drivers/gpu/drm/drm_dp_mst_topology.c

   1 /*
   2  * Copyright © 2014 Red Hat
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that copyright
   7  * notice and this permission notice appear in supporting documentation, and
   8  * that the name of the copyright holders not be used in advertising or
   9  * publicity pertaining to distribution of the software without specific,
  10  * written prior permission.  The copyright holders make no representations
  11  * about the suitability of this software for any purpose.  It is provided "as
  12  * is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20  * OF THIS SOFTWARE.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26 #include <linux/errno.h>
  27 #include <linux/sched.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/i2c.h>
  30 #include <drm/drm_dp_mst_helper.h>
  31 #include <drm/drmP.h>
  32
  33 #include <drm/drm_fixed.h>
  34
  35 /**
  36  * DOC: dp mst helper
  37  *
  38  * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
  39  * protocol. The helpers contain a topology manager and bandwidth manager.
  40  * The helpers encapsulate the sending and received of sideband msgs.
  41  */
  42 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
  43                                   char *buf);
  44 static int test_calc_pbn_mode(void);
  45
  46 static void drm_dp_put_port(struct drm_dp_mst_port *port);
  47
  48 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
  49                                      int id,
  50                                      struct drm_dp_payload *payload);
  51
  52 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
  53                                   struct drm_dp_mst_port *port,
  54                                   int offset, int size, u8 *bytes);
  55
  56 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
  57                                      struct drm_dp_mst_branch *mstb);
  58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
  59                                            struct drm_dp_mst_branch *mstb,
  60                                            struct drm_dp_mst_port *port);
  61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
  62                                  u8 *guid);
  63
  64 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
  65 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
  66 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
  67 /* sideband msg handling */
  68 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
  69 {
  70         u8 bitmask = 0x80;
  71         u8 bitshift = 7;
  72         u8 array_index = 0;
  73         int number_of_bits = num_nibbles * 4;
  74         u8 remainder = 0;
  75
  76         while (number_of_bits != 0) {
  77                 number_of_bits--;
  78                 remainder <<= 1;
  79                 remainder |= (data[array_index] & bitmask) >> bitshift;
  80                 bitmask >>= 1;
  81                 bitshift--;
  82                 if (bitmask == 0) {
  83                         bitmask = 0x80;
  84                         bitshift = 7;
  85                         array_index++;
  86                 }
  87                 if ((remainder & 0x10) == 0x10)
  88                         remainder ^= 0x13;
  89         }
  90
  91         number_of_bits = 4;
  92         while (number_of_bits != 0) {
  93                 number_of_bits--;
  94                 remainder <<= 1;
  95                 if ((remainder & 0x10) != 0)
  96                         remainder ^= 0x13;
  97         }
  98
  99         return remainder;
 100 }
 101
 102 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
 103 {
 104         u8 bitmask = 0x80;
 105         u8 bitshift = 7;
 106         u8 array_index = 0;
 107         int number_of_bits = number_of_bytes * 8;
 108         u16 remainder = 0;
 109
 110         while (number_of_bits != 0) {
 111                 number_of_bits--;
 112                 remainder <<= 1;
 113                 remainder |= (data[array_index] & bitmask) >> bitshift;
 114                 bitmask >>= 1;
 115                 bitshift--;
 116                 if (bitmask == 0) {
 117                         bitmask = 0x80;
 118                         bitshift = 7;
 119                         array_index++;
 120                 }
 121                 if ((remainder & 0x100) == 0x100)
 122                         remainder ^= 0xd5;
 123         }
 124
 125         number_of_bits = 8;
 126         while (number_of_bits != 0) {
 127                 number_of_bits--;
 128                 remainder <<= 1;
 129                 if ((remainder & 0x100) != 0)
 130                         remainder ^= 0xd5;
 131         }
 132
 133         return remainder & 0xff;
 134 }
 135 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
 136 {
 137         u8 size = 3;
 138         size += (hdr->lct / 2);
 139         return size;
 140 }
 141
 142 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 143                                            u8 *buf, int *len)
 144 {
 145         int idx = 0;
 146         int i;
 147         u8 crc4;
 148         buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
 149         for (i = 0; i < (hdr->lct / 2); i++)
 150                 buf[idx++] = hdr->rad[i];
 151         buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
 152                 (hdr->msg_len & 0x3f);
 153         buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
 154
 155         crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
 156         buf[idx - 1] |= (crc4 & 0xf);
 157
 158         *len = idx;
 159 }
 160
 161 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 162                                            u8 *buf, int buflen, u8 *hdrlen)
 163 {
 164         u8 crc4;
 165         u8 len;
 166         int i;
 167         u8 idx;
 168         if (buf[0] == 0)
 169                 return false;
 170         len = 3;
 171         len += ((buf[0] & 0xf0) >> 4) / 2;
 172         if (len > buflen)
 173                 return false;
 174         crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
 175
 176         if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
 177                 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
 178                 return false;
 179         }
 180
 181         hdr->lct = (buf[0] & 0xf0) >> 4;
 182         hdr->lcr = (buf[0] & 0xf);
 183         idx = 1;
 184         for (i = 0; i < (hdr->lct / 2); i++)
 185                 hdr->rad[i] = buf[idx++];
 186         hdr->broadcast = (buf[idx] >> 7) & 0x1;
 187         hdr->path_msg = (buf[idx] >> 6) & 0x1;
 188         hdr->msg_len = buf[idx] & 0x3f;
 189         idx++;
 190         hdr->somt = (buf[idx] >> 7) & 0x1;
 191         hdr->eomt = (buf[idx] >> 6) & 0x1;
 192         hdr->seqno = (buf[idx] >> 4) & 0x1;
 193         idx++;
 194         *hdrlen = idx;
 195         return true;
 196 }
 197
 198 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
 199                                        struct drm_dp_sideband_msg_tx *raw)
 200 {
 201         int idx = 0;
 202         int i;
 203         u8 *buf = raw->msg;
 204         buf[idx++] = req->req_type & 0x7f;
 205
 206         switch (req->req_type) {
 207         case DP_ENUM_PATH_RESOURCES:
 208                 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
 209                 idx++;
 210                 break;
 211         case DP_ALLOCATE_PAYLOAD:
 212                 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
 213                         (req->u.allocate_payload.number_sdp_streams & 0xf);
 214                 idx++;
 215                 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
 216                 idx++;
 217                 buf[idx] = (req->u.allocate_payload.pbn >> 8);
 218                 idx++;
 219                 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
 220                 idx++;
 221                 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
 222                         buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
 223                                 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
 224                         idx++;
 225                 }
 226                 if (req->u.allocate_payload.number_sdp_streams & 1) {
 227                         i = req->u.allocate_payload.number_sdp_streams - 1;
 228                         buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
 229                         idx++;
 230                 }
 231                 break;
 232         case DP_QUERY_PAYLOAD:
 233                 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
 234                 idx++;
 235                 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
 236                 idx++;
 237                 break;
 238         case DP_REMOTE_DPCD_READ:
 239                 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
 240                 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
 241                 idx++;
 242                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
 243                 idx++;
 244                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
 245                 idx++;
 246                 buf[idx] = (req->u.dpcd_read.num_bytes);
 247                 idx++;
 248                 break;
 249
 250         case DP_REMOTE_DPCD_WRITE:
 251                 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
 252                 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
 253                 idx++;
 254                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
 255                 idx++;
 256                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
 257                 idx++;
 258                 buf[idx] = (req->u.dpcd_write.num_bytes);
 259                 idx++;
 260                 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
 261                 idx += req->u.dpcd_write.num_bytes;
 262                 break;
 263         case DP_REMOTE_I2C_READ:
 264                 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
 265                 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
 266                 idx++;
 267                 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
 268                         buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
 269                         idx++;
 270                         buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
 271                         idx++;
 272                         memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
 273                         idx += req->u.i2c_read.transactions[i].num_bytes;
 274
 275                         buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
 276                         buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
 277                         idx++;
 278                 }
 279                 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
 280                 idx++;
 281                 buf[idx] = (req->u.i2c_read.num_bytes_read);
 282                 idx++;
 283                 break;
 284
 285         case DP_REMOTE_I2C_WRITE:
 286                 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
 287                 idx++;
 288                 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
 289                 idx++;
 290                 buf[idx] = (req->u.i2c_write.num_bytes);
 291                 idx++;
 292                 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
 293                 idx += req->u.i2c_write.num_bytes;
 294                 break;
 295         }
 296         raw->cur_len = idx;
 297 }
 298
 299 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
 300 {
 301         u8 crc4;
 302         crc4 = drm_dp_msg_data_crc4(msg, len);
 303         msg[len] = crc4;
 304 }
 305
 306 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
 307                                          struct drm_dp_sideband_msg_tx *raw)
 308 {
 309         int idx = 0;
 310         u8 *buf = raw->msg;
 311
 312         buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
 313
 314         raw->cur_len = idx;
 315 }
 316
 317 /* this adds a chunk of msg to the builder to get the final msg */
 318 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
 319                                       u8 *replybuf, u8 replybuflen, bool hdr)
 320 {
 321         int ret;
 322         u8 crc4;
 323
 324         if (hdr) {
 325                 u8 hdrlen;
 326                 struct drm_dp_sideband_msg_hdr recv_hdr;
 327                 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
 328                 if (ret == false) {
 329                         print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
 330                         return false;
 331                 }
 332
 333                 /* get length contained in this portion */
 334                 msg->curchunk_len = recv_hdr.msg_len;
 335                 msg->curchunk_hdrlen = hdrlen;
 336
 337                 /* we have already gotten an somt - don't bother parsing */
 338                 if (recv_hdr.somt && msg->have_somt)
 339                         return false;
 340
 341                 if (recv_hdr.somt) {
 342                         memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
 343                         msg->have_somt = true;
 344                 }
 345                 if (recv_hdr.eomt)
 346                         msg->have_eomt = true;
 347
 348                 /* copy the bytes for the remainder of this header chunk */
 349                 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
 350                 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
 351         } else {
 352                 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
 353                 msg->curchunk_idx += replybuflen;
 354         }
 355
 356         if (msg->curchunk_idx >= msg->curchunk_len) {
 357                 /* do CRC */
 358                 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
 359                 /* copy chunk into bigger msg */
 360                 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 361                 msg->curlen += msg->curchunk_len - 1;
 362         }
 363         return true;
 364 }
 365
 366 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
 367                                                struct drm_dp_sideband_msg_reply_body *repmsg)
 368 {
 369         int idx = 1;
 370         int i;
 371         memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
 372         idx += 16;
 373         repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
 374         idx++;
 375         if (idx > raw->curlen)
 376                 goto fail_len;
 377         for (i = 0; i < repmsg->u.link_addr.nports; i++) {
 378                 if (raw->msg[idx] & 0x80)
 379                         repmsg->u.link_addr.ports[i].input_port = 1;
 380
 381                 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
 382                 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
 383
 384                 idx++;
 385                 if (idx > raw->curlen)
 386                         goto fail_len;
 387                 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
 388                 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
 389                 if (repmsg->u.link_addr.ports[i].input_port == 0)
 390                         repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 391                 idx++;
 392                 if (idx > raw->curlen)
 393                         goto fail_len;
 394                 if (repmsg->u.link_addr.ports[i].input_port == 0) {
 395                         repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
 396                         idx++;
 397                         if (idx > raw->curlen)
 398                                 goto fail_len;
 399                         memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
 400                         idx += 16;
 401                         if (idx > raw->curlen)
 402                                 goto fail_len;
 403                         repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
 404                         repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
 405                         idx++;
 406
 407                 }
 408                 if (idx > raw->curlen)
 409                         goto fail_len;
 410         }
 411
 412         return true;
 413 fail_len:
 414         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 415         return false;
 416 }
 417
 418 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
 419                                                    struct drm_dp_sideband_msg_reply_body *repmsg)
 420 {
 421         int idx = 1;
 422         repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
 423         idx++;
 424         if (idx > raw->curlen)
 425                 goto fail_len;
 426         repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
 427         if (idx > raw->curlen)
 428                 goto fail_len;
 429
 430         memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
 431         return true;
 432 fail_len:
 433         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 434         return false;
 435 }
 436
 437 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
 438                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 439 {
 440         int idx = 1;
 441         repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
 442         idx++;
 443         if (idx > raw->curlen)
 444                 goto fail_len;
 445         return true;
 446 fail_len:
 447         DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
 448         return false;
 449 }
 450
 451 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
 452                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 453 {
 454         int idx = 1;
 455
 456         repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
 457         idx++;
 458         if (idx > raw->curlen)
 459                 goto fail_len;
 460         repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
 461         idx++;
 462         /* TODO check */
 463         memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
 464         return true;
 465 fail_len:
 466         DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
 467         return false;
 468 }
 469
 470 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
 471                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 472 {
 473         int idx = 1;
 474         repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
 475         idx++;
 476         if (idx > raw->curlen)
 477                 goto fail_len;
 478         repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 479         idx += 2;
 480         if (idx > raw->curlen)
 481                 goto fail_len;
 482         repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 483         idx += 2;
 484         if (idx > raw->curlen)
 485                 goto fail_len;
 486         return true;
 487 fail_len:
 488         DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
 489         return false;
 490 }
 491
 492 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 493                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 494 {
 495         int idx = 1;
 496         repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 497         idx++;
 498         if (idx > raw->curlen)
 499                 goto fail_len;
 500         repmsg->u.allocate_payload.vcpi = raw->msg[idx];
 501         idx++;
 502         if (idx > raw->curlen)
 503                 goto fail_len;
 504         repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 505         idx += 2;
 506         if (idx > raw->curlen)
 507                 goto fail_len;
 508         return true;
 509 fail_len:
 510         DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
 511         return false;
 512 }
 513
 514 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 515                                                     struct drm_dp_sideband_msg_reply_body *repmsg)
 516 {
 517         int idx = 1;
 518         repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 519         idx++;
 520         if (idx > raw->curlen)
 521                 goto fail_len;
 522         repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 523         idx += 2;
 524         if (idx > raw->curlen)
 525                 goto fail_len;
 526         return true;
 527 fail_len:
 528         DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
 529         return false;
 530 }
 531
 532 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
 533                                         struct drm_dp_sideband_msg_reply_body *msg)
 534 {
 535         memset(msg, 0, sizeof(*msg));
 536         msg->reply_type = (raw->msg[0] & 0x80) >> 7;
 537         msg->req_type = (raw->msg[0] & 0x7f);
 538
 539         if (msg->reply_type) {
 540                 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
 541                 msg->u.nak.reason = raw->msg[17];
 542                 msg->u.nak.nak_data = raw->msg[18];
 543                 return false;
 544         }
 545
 546         switch (msg->req_type) {
 547         case DP_LINK_ADDRESS:
 548                 return drm_dp_sideband_parse_link_address(raw, msg);
 549         case DP_QUERY_PAYLOAD:
 550                 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
 551         case DP_REMOTE_DPCD_READ:
 552                 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
 553         case DP_REMOTE_DPCD_WRITE:
 554                 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
 555         case DP_REMOTE_I2C_READ:
 556                 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
 557         case DP_ENUM_PATH_RESOURCES:
 558                 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
 559         case DP_ALLOCATE_PAYLOAD:
 560                 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
 561         default:
 562                 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
 563                 return false;
 564         }
 565 }
 566
 567 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
 568                                                            struct drm_dp_sideband_msg_req_body *msg)
 569 {
 570         int idx = 1;
 571
 572         msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 573         idx++;
 574         if (idx > raw->curlen)
 575                 goto fail_len;
 576
 577         memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
 578         idx += 16;
 579         if (idx > raw->curlen)
 580                 goto fail_len;
 581
 582         msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
 583         msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 584         msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
 585         msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
 586         msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
 587         idx++;
 588         return true;
 589 fail_len:
 590         DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
 591         return false;
 592 }
 593
 594 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
 595                                                            struct drm_dp_sideband_msg_req_body *msg)
 596 {
 597         int idx = 1;
 598
 599         msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 600         idx++;
 601         if (idx > raw->curlen)
 602                 goto fail_len;
 603
 604         memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
 605         idx += 16;
 606         if (idx > raw->curlen)
 607                 goto fail_len;
 608
 609         msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 610         idx++;
 611         return true;
 612 fail_len:
 613         DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
 614         return false;
 615 }
 616
 617 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
 618                                       struct drm_dp_sideband_msg_req_body *msg)
 619 {
 620         memset(msg, 0, sizeof(*msg));
 621         msg->req_type = (raw->msg[0] & 0x7f);
 622
 623         switch (msg->req_type) {
 624         case DP_CONNECTION_STATUS_NOTIFY:
 625                 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
 626         case DP_RESOURCE_STATUS_NOTIFY:
 627                 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
 628         default:
 629                 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
 630                 return false;
 631         }
 632 }
 633
 634 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
 635 {
 636         struct drm_dp_sideband_msg_req_body req;
 637
 638         req.req_type = DP_REMOTE_DPCD_WRITE;
 639         req.u.dpcd_write.port_number = port_num;
 640         req.u.dpcd_write.dpcd_address = offset;
 641         req.u.dpcd_write.num_bytes = num_bytes;
 642         req.u.dpcd_write.bytes = bytes;
 643         drm_dp_encode_sideband_req(&req, msg);
 644
 645         return 0;
 646 }
 647
 648 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
 649 {
 650         struct drm_dp_sideband_msg_req_body req;
 651
 652         req.req_type = DP_LINK_ADDRESS;
 653         drm_dp_encode_sideband_req(&req, msg);
 654         return 0;
 655 }
 656
 657 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
 658 {
 659         struct drm_dp_sideband_msg_req_body req;
 660
 661         req.req_type = DP_ENUM_PATH_RESOURCES;
 662         req.u.port_num.port_number = port_num;
 663         drm_dp_encode_sideband_req(&req, msg);
 664         msg->path_msg = true;
 665         return 0;
 666 }
 667
 668 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
 669                                   u8 vcpi, uint16_t pbn,
 670                                   u8 number_sdp_streams,
 671                                   u8 *sdp_stream_sink)
 672 {
 673         struct drm_dp_sideband_msg_req_body req;
 674         memset(&req, 0, sizeof(req));
 675         req.req_type = DP_ALLOCATE_PAYLOAD;
 676         req.u.allocate_payload.port_number = port_num;
 677         req.u.allocate_payload.vcpi = vcpi;
 678         req.u.allocate_payload.pbn = pbn;
 679         req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
 680         memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
 681                    number_sdp_streams);
 682         drm_dp_encode_sideband_req(&req, msg);
 683         msg->path_msg = true;
 684         return 0;
 685 }
 686
 687 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 688                                         struct drm_dp_vcpi *vcpi)
 689 {
 690         int ret, vcpi_ret;
 691
 692         mutex_lock(&mgr->payload_lock);
 693         ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
 694         if (ret > mgr->max_payloads) {
 695                 ret = -EINVAL;
 696                 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
 697                 goto out_unlock;
 698         }
 699
 700         vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
 701         if (vcpi_ret > mgr->max_payloads) {
 702                 ret = -EINVAL;
 703                 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
 704                 goto out_unlock;
 705         }
 706
 707         set_bit(ret, &mgr->payload_mask);
 708         set_bit(vcpi_ret, &mgr->vcpi_mask);
 709         vcpi->vcpi = vcpi_ret + 1;
 710         mgr->proposed_vcpis[ret - 1] = vcpi;
 711 out_unlock:
 712         mutex_unlock(&mgr->payload_lock);
 713         return ret;
 714 }
 715
 716 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 717                                       int vcpi)
 718 {
 719         int i;
 720         if (vcpi == 0)
 721                 return;
 722
 723         mutex_lock(&mgr->payload_lock);
 724         DRM_DEBUG_KMS("putting payload %d\n", vcpi);
 725         clear_bit(vcpi - 1, &mgr->vcpi_mask);
 726
 727         for (i = 0; i < mgr->max_payloads; i++) {
 728                 if (mgr->proposed_vcpis[i])
 729                         if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
 730                                 mgr->proposed_vcpis[i] = NULL;
 731                                 clear_bit(i + 1, &mgr->payload_mask);
 732                         }
 733         }
 734         mutex_unlock(&mgr->payload_lock);
 735 }
 736
 737 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 738                               struct drm_dp_sideband_msg_tx *txmsg)
 739 {
 740         bool ret;
 741
 742         /*
 743          * All updates to txmsg->state are protected by mgr->qlock, and the two
 744          * cases we check here are terminal states. For those the barriers
 745          * provided by the wake_up/wait_event pair are enough.
 746          */
 747         ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 748                txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 749         return ret;
 750 }
 751
 752 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 753                                     struct drm_dp_sideband_msg_tx *txmsg)
 754 {
 755         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 756         int ret;
 757
 758         ret = wait_event_timeout(mgr->tx_waitq,
 759                                  check_txmsg_state(mgr, txmsg),
 760                                  (4 * HZ));
 761         mutex_lock(&mstb->mgr->qlock);
 762         if (ret > 0) {
 763                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 764                         ret = -EIO;
 765                         goto out;
 766                 }
 767         } else {
 768                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 769
 770                 /* dump some state */
 771                 ret = -EIO;
 772
 773                 /* remove from q */
 774                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 775                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 776                         list_del(&txmsg->next);
 777                 }
 778
 779                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 780                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 781                         mstb->tx_slots[txmsg->seqno] = NULL;
 782                 }
 783         }
 784 out:
 785         mutex_unlock(&mgr->qlock);
 786
 787         return ret;
 788 }
 789
 790 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 791 {
 792         struct drm_dp_mst_branch *mstb;
 793
 794         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 795         if (!mstb)
 796                 return NULL;
 797
 798         mstb->lct = lct;
 799         if (lct > 1)
 800                 memcpy(mstb->rad, rad, lct / 2);
 801         INIT_LIST_HEAD(&mstb->ports);
 802         kref_init(&mstb->kref);
 803         return mstb;
 804 }
 805
 806 static void drm_dp_free_mst_port(struct kref *kref);
 807
 808 static void drm_dp_free_mst_branch_device(struct kref *kref)
 809 {
 810         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 811         if (mstb->port_parent) {
 812                 if (list_empty(&mstb->port_parent->next))
 813                         kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
 814         }
 815         kfree(mstb);
 816 }
 817
 818 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 819 {
 820         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 821         struct drm_dp_mst_port *port, *tmp;
 822         bool wake_tx = false;
 823
 824         /*
 825          * init kref again to be used by ports to remove mst branch when it is
 826          * not needed anymore
 827          */
 828         kref_init(kref);
 829
 830         if (mstb->port_parent && list_empty(&mstb->port_parent->next))
 831                 kref_get(&mstb->port_parent->kref);
 832
 833         /*
 834          * destroy all ports - don't need lock
 835          * as there are no more references to the mst branch
 836          * device at this point.
 837          */
 838         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 839                 list_del(&port->next);
 840                 drm_dp_put_port(port);
 841         }
 842
 843         /* drop any tx slots msg */
 844         mutex_lock(&mstb->mgr->qlock);
 845         if (mstb->tx_slots[0]) {
 846                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 847                 mstb->tx_slots[0] = NULL;
 848                 wake_tx = true;
 849         }
 850         if (mstb->tx_slots[1]) {
 851                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 852                 mstb->tx_slots[1] = NULL;
 853                 wake_tx = true;
 854         }
 855         mutex_unlock(&mstb->mgr->qlock);
 856
 857         if (wake_tx)
 858                 wake_up(&mstb->mgr->tx_waitq);
 859
 860         kref_put(kref, drm_dp_free_mst_branch_device);
 861 }
 862
 863 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 864 {
 865         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 866 }
 867
 868
 869 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 870 {
 871         struct drm_dp_mst_branch *mstb;
 872
 873         switch (old_pdt) {
 874         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 875         case DP_PEER_DEVICE_SST_SINK:
 876                 /* remove i2c over sideband */
 877                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 878                 break;
 879         case DP_PEER_DEVICE_MST_BRANCHING:
 880                 mstb = port->mstb;
 881                 port->mstb = NULL;
 882                 drm_dp_put_mst_branch_device(mstb);
 883                 break;
 884         }
 885 }
 886
 887 static void drm_dp_destroy_port(struct kref *kref)
 888 {
 889         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 890         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 891
 892         if (!port->input) {
 893                 port->vcpi.num_slots = 0;
 894
 895                 kfree(port->cached_edid);
 896
 897                 /*
 898                  * The only time we don't have a connector
 899                  * on an output port is if the connector init
 900                  * fails.
 901                  */
 902                 if (port->connector) {
 903                         /* we can't destroy the connector here, as
 904                          * we might be holding the mode_config.mutex
 905                          * from an EDID retrieval */
 906
 907                         mutex_lock(&mgr->destroy_connector_lock);
 908                         kref_get(&port->parent->kref);
 909                         list_add(&port->next, &mgr->destroy_connector_list);
 910                         mutex_unlock(&mgr->destroy_connector_lock);
 911                         schedule_work(&mgr->destroy_connector_work);
 912                         return;
 913                 }
 914                 /* no need to clean up vcpi
 915                  * as if we have no connector we never setup a vcpi */
 916                 drm_dp_port_teardown_pdt(port, port->pdt);
 917         }
 918         kfree(port);
 919 }
 920
 921 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 922 {
 923         kref_put(&port->kref, drm_dp_destroy_port);
 924 }
 925
 926 static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
 927 {
 928         struct drm_dp_mst_port *port;
 929         struct drm_dp_mst_branch *rmstb;
 930         if (to_find == mstb) {
 931                 kref_get(&mstb->kref);
 932                 return mstb;
 933         }
 934         list_for_each_entry(port, &mstb->ports, next) {
 935                 if (port->mstb) {
 936                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 937                         if (rmstb)
 938                                 return rmstb;
 939                 }
 940         }
 941         return NULL;
 942 }
 943
 944 static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
 945 {
 946         struct drm_dp_mst_branch *rmstb = NULL;
 947         mutex_lock(&mgr->lock);
 948         if (mgr->mst_primary)
 949                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 950         mutex_unlock(&mgr->lock);
 951         return rmstb;
 952 }
 953
 954 static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
 955 {
 956         struct drm_dp_mst_port *port, *mport;
 957
 958         list_for_each_entry(port, &mstb->ports, next) {
 959                 if (port == to_find) {
 960                         kref_get(&port->kref);
 961                         return port;
 962                 }
 963                 if (port->mstb) {
 964                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 965                         if (mport)
 966                                 return mport;
 967                 }
 968         }
 969         return NULL;
 970 }
 971
 972 static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
 973 {
 974         struct drm_dp_mst_port *rport = NULL;
 975         mutex_lock(&mgr->lock);
 976         if (mgr->mst_primary)
 977                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 978         mutex_unlock(&mgr->lock);
 979         return rport;
 980 }
 981
 982 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 983 {
 984         struct drm_dp_mst_port *port;
 985
 986         list_for_each_entry(port, &mstb->ports, next) {
 987                 if (port->port_num == port_num) {
 988                         kref_get(&port->kref);
 989                         return port;
 990                 }
 991         }
 992
 993         return NULL;
 994 }
 995
 996 /*
 997  * calculate a new RAD for this MST branch device
 998  * if parent has an LCT of 2 then it has 1 nibble of RAD,
 999  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1000  */
1001 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1002                                  u8 *rad)
1003 {
1004         int parent_lct = port->parent->lct;
1005         int shift = 4;
1006         int idx = (parent_lct - 1) / 2;
1007         if (parent_lct > 1) {
1008                 memcpy(rad, port->parent->rad, idx + 1);
1009                 shift = (parent_lct % 2) ? 4 : 0;
1010         } else
1011                 rad[0] = 0;
1012
1013         rad[idx] |= port->port_num << shift;
1014         return parent_lct + 1;
1015 }
1016
1017 /*
1018  * return sends link address for new mstb
1019  */
1020 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1021 {
1022         int ret;
1023         u8 rad[6], lct;
1024         bool send_link = false;
1025         switch (port->pdt) {
1026         case DP_PEER_DEVICE_DP_LEGACY_CONV:
1027         case DP_PEER_DEVICE_SST_SINK:
1028                 /* add i2c over sideband */
1029                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1030                 break;
1031         case DP_PEER_DEVICE_MST_BRANCHING:
1032                 lct = drm_dp_calculate_rad(port, rad);
1033
1034                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1035                 port->mstb->mgr = port->mgr;
1036                 port->mstb->port_parent = port;
1037
1038                 send_link = true;
1039                 break;
1040         }
1041         return send_link;
1042 }
1043
1044 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1045 {
1046         int ret;
1047
1048         memcpy(mstb->guid, guid, 16);
1049
1050         if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1051                 if (mstb->port_parent) {
1052                         ret = drm_dp_send_dpcd_write(
1053                                         mstb->mgr,
1054                                         mstb->port_parent,
1055                                         DP_GUID,
1056                                         16,
1057                                         mstb->guid);
1058                 } else {
1059
1060                         ret = drm_dp_dpcd_write(
1061                                         mstb->mgr->aux,
1062                                         DP_GUID,
1063                                         mstb->guid,
1064                                         16);
1065                 }
1066         }
1067 }
1068
1069 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1070                                 int pnum,
1071                                 char *proppath,
1072                                 size_t proppath_size)
1073 {
1074         int i;
1075         char temp[8];
1076         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1077         for (i = 0; i < (mstb->lct - 1); i++) {
1078                 int shift = (i % 2) ? 0 : 4;
1079                 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1080                 snprintf(temp, sizeof(temp), "-%d", port_num);
1081                 strlcat(proppath, temp, proppath_size);
1082         }
1083         snprintf(temp, sizeof(temp), "-%d", pnum);
1084         strlcat(proppath, temp, proppath_size);
1085 }
1086
1087 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1088                             struct device *dev,
1089                             struct drm_dp_link_addr_reply_port *port_msg)
1090 {
1091         struct drm_dp_mst_port *port;
1092         bool ret;
1093         bool created = false;
1094         int old_pdt = 0;
1095         int old_ddps = 0;
1096         port = drm_dp_get_port(mstb, port_msg->port_number);
1097         if (!port) {
1098                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1099                 if (!port)
1100                         return;
1101                 kref_init(&port->kref);
1102                 port->parent = mstb;
1103                 port->port_num = port_msg->port_number;
1104                 port->mgr = mstb->mgr;
1105                 port->aux.name = "DPMST";
1106                 port->aux.dev = dev;
1107                 created = true;
1108         } else {
1109                 old_pdt = port->pdt;
1110                 old_ddps = port->ddps;
1111         }
1112
1113         port->pdt = port_msg->peer_device_type;
1114         port->input = port_msg->input_port;
1115         port->mcs = port_msg->mcs;
1116         port->ddps = port_msg->ddps;
1117         port->ldps = port_msg->legacy_device_plug_status;
1118         port->dpcd_rev = port_msg->dpcd_revision;
1119         port->num_sdp_streams = port_msg->num_sdp_streams;
1120         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1121
1122         /* manage mstb port lists with mgr lock - take a reference
1123            for this list */
1124         if (created) {
1125                 mutex_lock(&mstb->mgr->lock);
1126                 kref_get(&port->kref);
1127                 list_add(&port->next, &mstb->ports);
1128                 mutex_unlock(&mstb->mgr->lock);
1129         }
1130
1131         if (old_ddps != port->ddps) {
1132                 if (port->ddps) {
1133                         if (!port->input)
1134                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1135                 } else {
1136                         port->available_pbn = 0;
1137                         }
1138         }
1139
1140         if (old_pdt != port->pdt && !port->input) {
1141                 drm_dp_port_teardown_pdt(port, old_pdt);
1142
1143                 ret = drm_dp_port_setup_pdt(port);
1144                 if (ret == true)
1145                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1146         }
1147
1148         if (created && !port->input) {
1149                 char proppath[255];
1150
1151                 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1152                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1153                 if (!port->connector) {
1154                         /* remove it from the port list */
1155                         mutex_lock(&mstb->mgr->lock);
1156                         list_del(&port->next);
1157                         mutex_unlock(&mstb->mgr->lock);
1158                         /* drop port list reference */
1159                         drm_dp_put_port(port);
1160                         goto out;
1161                 }
1162                 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1163                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1164                         drm_mode_connector_set_tile_property(port->connector);
1165                 }
1166                 (*mstb->mgr->cbs->register_connector)(port->connector);
1167         }
1168
1169 out:
1170         /* put reference to this port */
1171         drm_dp_put_port(port);
1172 }
1173
1174 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1175                                struct drm_dp_connection_status_notify *conn_stat)
1176 {
1177         struct drm_dp_mst_port *port;
1178         int old_pdt;
1179         int old_ddps;
1180         bool dowork = false;
1181         port = drm_dp_get_port(mstb, conn_stat->port_number);
1182         if (!port)
1183                 return;
1184
1185         old_ddps = port->ddps;
1186         old_pdt = port->pdt;
1187         port->pdt = conn_stat->peer_device_type;
1188         port->mcs = conn_stat->message_capability_status;
1189         port->ldps = conn_stat->legacy_device_plug_status;
1190         port->ddps = conn_stat->displayport_device_plug_status;
1191
1192         if (old_ddps != port->ddps) {
1193                 if (port->ddps) {
1194                         dowork = true;
1195                 } else {
1196                         port->available_pbn = 0;
1197                 }
1198         }
1199         if (old_pdt != port->pdt && !port->input) {
1200                 drm_dp_port_teardown_pdt(port, old_pdt);
1201
1202                 if (drm_dp_port_setup_pdt(port))
1203                         dowork = true;
1204         }
1205
1206         drm_dp_put_port(port);
1207         if (dowork)
1208                 queue_work(system_long_wq, &mstb->mgr->work);
1209
1210 }
1211
1212 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1213                                                                u8 lct, u8 *rad)
1214 {
1215         struct drm_dp_mst_branch *mstb;
1216         struct drm_dp_mst_port *port;
1217         int i;
1218         /* find the port by iterating down */
1219
1220         mutex_lock(&mgr->lock);
1221         mstb = mgr->mst_primary;
1222
1223         for (i = 0; i < lct - 1; i++) {
1224                 int shift = (i % 2) ? 0 : 4;
1225                 int port_num = (rad[i / 2] >> shift) & 0xf;
1226
1227                 list_for_each_entry(port, &mstb->ports, next) {
1228                         if (port->port_num == port_num) {
1229                                 mstb = port->mstb;
1230                                 if (!mstb) {
1231                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1232                                         goto out;
1233                                 }
1234
1235                                 break;
1236                         }
1237                 }
1238         }
1239         kref_get(&mstb->kref);
1240 out:
1241         mutex_unlock(&mgr->lock);
1242         return mstb;
1243 }
1244
1245 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1246         struct drm_dp_mst_branch *mstb,
1247         uint8_t *guid)
1248 {
1249         struct drm_dp_mst_branch *found_mstb;
1250         struct drm_dp_mst_port *port;
1251
1252         if (memcmp(mstb->guid, guid, 16) == 0)
1253                 return mstb;
1254
1255
1256         list_for_each_entry(port, &mstb->ports, next) {
1257                 if (!port->mstb)
1258                         continue;
1259
1260                 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1261
1262                 if (found_mstb)
1263                         return found_mstb;
1264         }
1265
1266         return NULL;
1267 }
1268
1269 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1270         struct drm_dp_mst_topology_mgr *mgr,
1271         uint8_t *guid)
1272 {
1273         struct drm_dp_mst_branch *mstb;
1274
1275         /* find the port by iterating down */
1276         mutex_lock(&mgr->lock);
1277
1278         mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1279
1280         if (mstb)
1281                 kref_get(&mstb->kref);
1282
1283         mutex_unlock(&mgr->lock);
1284         return mstb;
1285 }
1286
1287 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1288                                                struct drm_dp_mst_branch *mstb)
1289 {
1290         struct drm_dp_mst_port *port;
1291         struct drm_dp_mst_branch *mstb_child;
1292         if (!mstb->link_address_sent)
1293                 drm_dp_send_link_address(mgr, mstb);
1294
1295         list_for_each_entry(port, &mstb->ports, next) {
1296                 if (port->input)
1297                         continue;
1298
1299                 if (!port->ddps)
1300                         continue;
1301
1302                 if (!port->available_pbn)
1303                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1304
1305                 if (port->mstb) {
1306                         mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1307                         if (mstb_child) {
1308                                 drm_dp_check_and_send_link_address(mgr, mstb_child);
1309                                 drm_dp_put_mst_branch_device(mstb_child);
1310                         }
1311                 }
1312         }
1313 }
1314
1315 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1316 {
1317         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1318         struct drm_dp_mst_branch *mstb;
1319
1320         mutex_lock(&mgr->lock);
1321         mstb = mgr->mst_primary;
1322         if (mstb) {
1323                 kref_get(&mstb->kref);
1324         }
1325         mutex_unlock(&mgr->lock);
1326         if (mstb) {
1327                 drm_dp_check_and_send_link_address(mgr, mstb);
1328                 drm_dp_put_mst_branch_device(mstb);
1329         }
1330 }
1331
1332 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1333                                  u8 *guid)
1334 {
1335         static u8 zero_guid[16];
1336
1337         if (!memcmp(guid, zero_guid, 16)) {
1338                 u64 salt = get_jiffies_64();
1339                 memcpy(&guid[0], &salt, sizeof(u64));
1340                 memcpy(&guid[8], &salt, sizeof(u64));
1341                 return false;
1342         }
1343         return true;
1344 }
1345
1346 #if 0
1347 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1348 {
1349         struct drm_dp_sideband_msg_req_body req;
1350
1351         req.req_type = DP_REMOTE_DPCD_READ;
1352         req.u.dpcd_read.port_number = port_num;
1353         req.u.dpcd_read.dpcd_address = offset;
1354         req.u.dpcd_read.num_bytes = num_bytes;
1355         drm_dp_encode_sideband_req(&req, msg);
1356
1357         return 0;
1358 }
1359 #endif
1360
1361 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1362                                     bool up, u8 *msg, int len)
1363 {
1364         int ret;
1365         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1366         int tosend, total, offset;
1367         int retries = 0;
1368
1369 retry:
1370         total = len;
1371         offset = 0;
1372         do {
1373                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1374
1375                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1376                                         &msg[offset],
1377                                         tosend);
1378                 if (ret != tosend) {
1379                         if (ret == -EIO && retries < 5) {
1380                                 retries++;
1381                                 goto retry;
1382                         }
1383                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1384
1385                         return -EIO;
1386                 }
1387                 offset += tosend;
1388                 total -= tosend;
1389         } while (total > 0);
1390         return 0;
1391 }
1392
1393 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1394                                   struct drm_dp_sideband_msg_tx *txmsg)
1395 {
1396         struct drm_dp_mst_branch *mstb = txmsg->dst;
1397         u8 req_type;
1398
1399         /* both msg slots are full */
1400         if (txmsg->seqno == -1) {
1401                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1402                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1403                         return -EAGAIN;
1404                 }
1405                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1406                         txmsg->seqno = mstb->last_seqno;
1407                         mstb->last_seqno ^= 1;
1408                 } else if (mstb->tx_slots[0] == NULL)
1409                         txmsg->seqno = 0;
1410                 else
1411                         txmsg->seqno = 1;
1412                 mstb->tx_slots[txmsg->seqno] = txmsg;
1413         }
1414
1415         req_type = txmsg->msg[0] & 0x7f;
1416         if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1417                 req_type == DP_RESOURCE_STATUS_NOTIFY)
1418                 hdr->broadcast = 1;
1419         else
1420                 hdr->broadcast = 0;
1421         hdr->path_msg = txmsg->path_msg;
1422         hdr->lct = mstb->lct;
1423         hdr->lcr = mstb->lct - 1;
1424         if (mstb->lct > 1)
1425                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1426         hdr->seqno = txmsg->seqno;
1427         return 0;
1428 }
1429 /*
1430  * process a single block of the next message in the sideband queue
1431  */
1432 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1433                                    struct drm_dp_sideband_msg_tx *txmsg,
1434                                    bool up)
1435 {
1436         u8 chunk[48];
1437         struct drm_dp_sideband_msg_hdr hdr;
1438         int len, space, idx, tosend;
1439         int ret;
1440
1441         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1442
1443         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1444                 txmsg->seqno = -1;
1445                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1446         }
1447
1448         /* make hdr from dst mst - for replies use seqno
1449            otherwise assign one */
1450         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1451         if (ret < 0)
1452                 return ret;
1453
1454         /* amount left to send in this message */
1455         len = txmsg->cur_len - txmsg->cur_offset;
1456
1457         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1458         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1459
1460         tosend = min(len, space);
1461         if (len == txmsg->cur_len)
1462                 hdr.somt = 1;
1463         if (space >= len)
1464                 hdr.eomt = 1;
1465
1466
1467         hdr.msg_len = tosend + 1;
1468         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1469         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1470         /* add crc at end */
1471         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1472         idx += tosend + 1;
1473
1474         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1475         if (ret) {
1476                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1477                 return ret;
1478         }
1479
1480         txmsg->cur_offset += tosend;
1481         if (txmsg->cur_offset == txmsg->cur_len) {
1482                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1483                 return 1;
1484         }
1485         return 0;
1486 }
1487
1488 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1489 {
1490         struct drm_dp_sideband_msg_tx *txmsg;
1491         int ret;
1492
1493         WARN_ON(!mutex_is_locked(&mgr->qlock));
1494
1495         /* construct a chunk from the first msg in the tx_msg queue */
1496         if (list_empty(&mgr->tx_msg_downq)) {
1497                 mgr->tx_down_in_progress = false;
1498                 return;
1499         }
1500         mgr->tx_down_in_progress = true;
1501
1502         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1503         ret = process_single_tx_qlock(mgr, txmsg, false);
1504         if (ret == 1) {
1505                 /* txmsg is sent it should be in the slots now */
1506                 list_del(&txmsg->next);
1507         } else if (ret) {
1508                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1509                 list_del(&txmsg->next);
1510                 if (txmsg->seqno != -1)
1511                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1512                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1513                 wake_up(&mgr->tx_waitq);
1514         }
1515         if (list_empty(&mgr->tx_msg_downq)) {
1516                 mgr->tx_down_in_progress = false;
1517                 return;
1518         }
1519 }
1520
1521 /* called holding qlock */
1522 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1523                                        struct drm_dp_sideband_msg_tx *txmsg)
1524 {
1525         int ret;
1526
1527         /* construct a chunk from the first msg in the tx_msg queue */
1528         ret = process_single_tx_qlock(mgr, txmsg, true);
1529
1530         if (ret != 1)
1531                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1532
1533         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1534 }
1535
1536 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1537                                  struct drm_dp_sideband_msg_tx *txmsg)
1538 {
1539         mutex_lock(&mgr->qlock);
1540         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1541         if (!mgr->tx_down_in_progress)
1542                 process_single_down_tx_qlock(mgr);
1543         mutex_unlock(&mgr->qlock);
1544 }
1545
1546 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1547                                      struct drm_dp_mst_branch *mstb)
1548 {
1549         int len;
1550         struct drm_dp_sideband_msg_tx *txmsg;
1551         int ret;
1552
1553         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1554         if (!txmsg)
1555                 return;
1556
1557         txmsg->dst = mstb;
1558         len = build_link_address(txmsg);
1559
1560         mstb->link_address_sent = true;
1561         drm_dp_queue_down_tx(mgr, txmsg);
1562
1563         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1564         if (ret > 0) {
1565                 int i;
1566
1567                 if (txmsg->reply.reply_type == 1)
1568                         DRM_DEBUG_KMS("link address nak received\n");
1569                 else {
1570                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1571                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1572                                 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
1573                                        txmsg->reply.u.link_addr.ports[i].input_port,
1574                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1575                                        txmsg->reply.u.link_addr.ports[i].port_number,
1576                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1577                                        txmsg->reply.u.link_addr.ports[i].mcs,
1578                                        txmsg->reply.u.link_addr.ports[i].ddps,
1579                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1580                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1581                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1582                         }
1583
1584                         drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1585
1586                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1587                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1588                         }
1589                         (*mgr->cbs->hotplug)(mgr);
1590                 }
1591         } else {
1592                 mstb->link_address_sent = false;
1593                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1594         }
1595
1596         kfree(txmsg);
1597 }
1598
1599 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1600                                            struct drm_dp_mst_branch *mstb,
1601                                            struct drm_dp_mst_port *port)
1602 {
1603         int len;
1604         struct drm_dp_sideband_msg_tx *txmsg;
1605         int ret;
1606
1607         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1608         if (!txmsg)
1609                 return -ENOMEM;
1610
1611         txmsg->dst = mstb;
1612         len = build_enum_path_resources(txmsg, port->port_num);
1613
1614         drm_dp_queue_down_tx(mgr, txmsg);
1615
1616         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1617         if (ret > 0) {
1618                 if (txmsg->reply.reply_type == 1)
1619                         DRM_DEBUG_KMS("enum path resources nak received\n");
1620                 else {
1621                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1622                                 DRM_ERROR("got incorrect port in response\n");
1623                         DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
1624                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1625                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1626                 }
1627         }
1628
1629         kfree(txmsg);
1630         return 0;
1631 }
1632
1633 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1634 {
1635         if (!mstb->port_parent)
1636                 return NULL;
1637
1638         if (mstb->port_parent->mstb != mstb)
1639                 return mstb->port_parent;
1640
1641         return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1642 }
1643
1644 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1645                                                                          struct drm_dp_mst_branch *mstb,
1646                                                                          int *port_num)
1647 {
1648         struct drm_dp_mst_branch *rmstb = NULL;
1649         struct drm_dp_mst_port *found_port;
1650         mutex_lock(&mgr->lock);
1651         if (mgr->mst_primary) {
1652                 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1653
1654                 if (found_port) {
1655                         rmstb = found_port->parent;
1656                         kref_get(&rmstb->kref);
1657                         *port_num = found_port->port_num;
1658                 }
1659         }
1660         mutex_unlock(&mgr->lock);
1661         return rmstb;
1662 }
1663
1664 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1665                                    struct drm_dp_mst_port *port,
1666                                    int id,
1667                                    int pbn)
1668 {
1669         struct drm_dp_sideband_msg_tx *txmsg;
1670         struct drm_dp_mst_branch *mstb;
1671         int len, ret, port_num;
1672         u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1673         int i;
1674
1675         port = drm_dp_get_validated_port_ref(mgr, port);
1676         if (!port)
1677                 return -EINVAL;
1678
1679         port_num = port->port_num;
1680         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1681         if (!mstb) {
1682                 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1683
1684                 if (!mstb) {
1685                         drm_dp_put_port(port);
1686                         return -EINVAL;
1687                 }
1688         }
1689
1690         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1691         if (!txmsg) {
1692                 ret = -ENOMEM;
1693                 goto fail_put;
1694         }
1695
1696         for (i = 0; i < port->num_sdp_streams; i++)
1697                 sinks[i] = i;
1698
1699         txmsg->dst = mstb;
1700         len = build_allocate_payload(txmsg, port_num,
1701                                      id,
1702                                      pbn, port->num_sdp_streams, sinks);
1703
1704         drm_dp_queue_down_tx(mgr, txmsg);
1705
1706         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1707         if (ret > 0) {
1708                 if (txmsg->reply.reply_type == 1) {
1709                         ret = -EINVAL;
1710                 } else
1711                         ret = 0;
1712         }
1713         kfree(txmsg);
1714 fail_put:
1715         drm_dp_put_mst_branch_device(mstb);
1716         drm_dp_put_port(port);
1717         return ret;
1718 }
1719
1720 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1721                                        int id,
1722                                        struct drm_dp_payload *payload)
1723 {
1724         int ret;
1725
1726         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1727         if (ret < 0) {
1728                 payload->payload_state = 0;
1729                 return ret;
1730         }
1731         payload->payload_state = DP_PAYLOAD_LOCAL;
1732         return 0;
1733 }
1734
1735 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1736                                        struct drm_dp_mst_port *port,
1737                                        int id,
1738                                        struct drm_dp_payload *payload)
1739 {
1740         int ret;
1741         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1742         if (ret < 0)
1743                 return ret;
1744         payload->payload_state = DP_PAYLOAD_REMOTE;
1745         return ret;
1746 }
1747
1748 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1749                                         struct drm_dp_mst_port *port,
1750                                         int id,
1751                                         struct drm_dp_payload *payload)
1752 {
1753         DRM_DEBUG_KMS("\n");
1754         /* its okay for these to fail */
1755         if (port) {
1756                 drm_dp_payload_send_msg(mgr, port, id, 0);
1757         }
1758
1759         drm_dp_dpcd_write_payload(mgr, id, payload);
1760         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1761         return 0;
1762 }
1763
1764 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1765                                         int id,
1766                                         struct drm_dp_payload *payload)
1767 {
1768         payload->payload_state = 0;
1769         return 0;
1770 }
1771
1772 /**
1773  * drm_dp_update_payload_part1() - Execute payload update part 1
1774  * @mgr: manager to use.
1775  *
1776  * This iterates over all proposed virtual channels, and tries to
1777  * allocate space in the link for them. For 0->slots transitions,
1778  * this step just writes the VCPI to the MST device. For slots->0
1779  * transitions, this writes the updated VCPIs and removes the
1780  * remote VC payloads.
1781  *
1782  * after calling this the driver should generate ACT and payload
1783  * packets.
1784  */
1785 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1786 {
1787         int i, j;
1788         int cur_slots = 1;
1789         struct drm_dp_payload req_payload;
1790         struct drm_dp_mst_port *port;
1791
1792         mutex_lock(&mgr->payload_lock);
1793         for (i = 0; i < mgr->max_payloads; i++) {
1794                 /* solve the current payloads - compare to the hw ones
1795                    - update the hw view */
1796                 req_payload.start_slot = cur_slots;
1797                 if (mgr->proposed_vcpis[i]) {
1798                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1799                         port = drm_dp_get_validated_port_ref(mgr, port);
1800                         if (!port) {
1801                                 mutex_unlock(&mgr->payload_lock);
1802                                 return -EINVAL;
1803                         }
1804                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1805                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1806                 } else {
1807                         port = NULL;
1808                         req_payload.num_slots = 0;
1809                 }
1810
1811                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1812                         mgr->payloads[i].start_slot = req_payload.start_slot;
1813                 }
1814                 /* work out what is required to happen with this payload */
1815                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1816
1817                         /* need to push an update for this payload */
1818                         if (req_payload.num_slots) {
1819                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1820                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1821                                 mgr->payloads[i].vcpi = req_payload.vcpi;
1822                         } else if (mgr->payloads[i].num_slots) {
1823                                 mgr->payloads[i].num_slots = 0;
1824                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1825                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1826                                 mgr->payloads[i].start_slot = 0;
1827                         }
1828                         mgr->payloads[i].payload_state = req_payload.payload_state;
1829                 }
1830                 cur_slots += req_payload.num_slots;
1831
1832                 if (port)
1833                         drm_dp_put_port(port);
1834         }
1835
1836         for (i = 0; i < mgr->max_payloads; i++) {
1837                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1838                         DRM_DEBUG_KMS("removing payload %d\n", i);
1839                         for (j = i; j < mgr->max_payloads - 1; j++) {
1840                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1841                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1842                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1843                                         set_bit(j + 1, &mgr->payload_mask);
1844                                 } else {
1845                                         clear_bit(j + 1, &mgr->payload_mask);
1846                                 }
1847                         }
1848                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1849                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1850                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1851
1852                 }
1853         }
1854         mutex_unlock(&mgr->payload_lock);
1855
1856         return 0;
1857 }
1858 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1859
1860 /**
1861  * drm_dp_update_payload_part2() - Execute payload update part 2
1862  * @mgr: manager to use.
1863  *
1864  * This iterates over all proposed virtual channels, and tries to
1865  * allocate space in the link for them. For 0->slots transitions,
1866  * this step writes the remote VC payload commands. For slots->0
1867  * this just resets some internal state.
1868  */
1869 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1870 {
1871         struct drm_dp_mst_port *port;
1872         int i;
1873         int ret = 0;
1874         mutex_lock(&mgr->payload_lock);
1875         for (i = 0; i < mgr->max_payloads; i++) {
1876
1877                 if (!mgr->proposed_vcpis[i])
1878                         continue;
1879
1880                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1881
1882                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1883                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1884                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1885                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1886                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1887                 }
1888                 if (ret) {
1889                         mutex_unlock(&mgr->payload_lock);
1890                         return ret;
1891                 }
1892         }
1893         mutex_unlock(&mgr->payload_lock);
1894         return 0;
1895 }
1896 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1897
1898 #if 0 /* unused as of yet */
1899 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1900                                  struct drm_dp_mst_port *port,
1901                                  int offset, int size)
1902 {
1903         int len;
1904         struct drm_dp_sideband_msg_tx *txmsg;
1905
1906         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1907         if (!txmsg)
1908                 return -ENOMEM;
1909
1910         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1911         txmsg->dst = port->parent;
1912
1913         drm_dp_queue_down_tx(mgr, txmsg);
1914
1915         return 0;
1916 }
1917 #endif
1918
1919 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1920                                   struct drm_dp_mst_port *port,
1921                                   int offset, int size, u8 *bytes)
1922 {
1923         int len;
1924         int ret;
1925         struct drm_dp_sideband_msg_tx *txmsg;
1926         struct drm_dp_mst_branch *mstb;
1927
1928         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1929         if (!mstb)
1930                 return -EINVAL;
1931
1932         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1933         if (!txmsg) {
1934                 ret = -ENOMEM;
1935                 goto fail_put;
1936         }
1937
1938         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1939         txmsg->dst = mstb;
1940
1941         drm_dp_queue_down_tx(mgr, txmsg);
1942
1943         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1944         if (ret > 0) {
1945                 if (txmsg->reply.reply_type == 1) {
1946                         ret = -EINVAL;
1947                 } else
1948                         ret = 0;
1949         }
1950         kfree(txmsg);
1951 fail_put:
1952         drm_dp_put_mst_branch_device(mstb);
1953         return ret;
1954 }
1955
1956 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1957 {
1958         struct drm_dp_sideband_msg_reply_body reply;
1959
1960         reply.reply_type = 0;
1961         reply.req_type = req_type;
1962         drm_dp_encode_sideband_reply(&reply, msg);
1963         return 0;
1964 }
1965
1966 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1967                                     struct drm_dp_mst_branch *mstb,
1968                                     int req_type, int seqno, bool broadcast)
1969 {
1970         struct drm_dp_sideband_msg_tx *txmsg;
1971
1972         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1973         if (!txmsg)
1974                 return -ENOMEM;
1975
1976         txmsg->dst = mstb;
1977         txmsg->seqno = seqno;
1978         drm_dp_encode_up_ack_reply(txmsg, req_type);
1979
1980         mutex_lock(&mgr->qlock);
1981
1982         process_single_up_tx_qlock(mgr, txmsg);
1983
1984         mutex_unlock(&mgr->qlock);
1985
1986         kfree(txmsg);
1987         return 0;
1988 }
1989
1990 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1991                                      int dp_link_count,
1992                                      int *out)
1993 {
1994         switch (dp_link_bw) {
1995         default:
1996                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1997                               dp_link_bw, dp_link_count);
1998                 return false;
1999
2000         case DP_LINK_BW_1_62:
2001                 *out = 3 * dp_link_count;
2002                 break;
2003         case DP_LINK_BW_2_7:
2004                 *out = 5 * dp_link_count;
2005                 break;
2006         case DP_LINK_BW_5_4:
2007                 *out = 10 * dp_link_count;
2008                 break;
2009         }
2010         return true;
2011 }
2012
2013 /**
2014  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2015  * @mgr: manager to set state for
2016  * @mst_state: true to enable MST on this connector - false to disable.
2017  *
2018  * This is called by the driver when it detects an MST capable device plugged
2019  * into a DP MST capable port, or when a DP MST capable device is unplugged.
2020  */
2021 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2022 {
2023         int ret = 0;
2024         struct drm_dp_mst_branch *mstb = NULL;
2025
2026         mutex_lock(&mgr->lock);
2027         if (mst_state == mgr->mst_state)
2028                 goto out_unlock;
2029
2030         mgr->mst_state = mst_state;
2031         /* set the device into MST mode */
2032         if (mst_state) {
2033                 WARN_ON(mgr->mst_primary);
2034
2035                 /* get dpcd info */
2036                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2037                 if (ret != DP_RECEIVER_CAP_SIZE) {
2038                         DRM_DEBUG_KMS("failed to read DPCD\n");
2039                         goto out_unlock;
2040                 }
2041
2042                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2043                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2044                                               &mgr->pbn_div)) {
2045                         ret = -EINVAL;
2046                         goto out_unlock;
2047                 }
2048
2049                 mgr->total_pbn = 2560;
2050                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2051                 mgr->avail_slots = mgr->total_slots;
2052
2053                 /* add initial branch device at LCT 1 */
2054                 mstb = drm_dp_add_mst_branch_device(1, NULL);
2055                 if (mstb == NULL) {
2056                         ret = -ENOMEM;
2057                         goto out_unlock;
2058                 }
2059                 mstb->mgr = mgr;
2060
2061                 /* give this the main reference */
2062                 mgr->mst_primary = mstb;
2063                 kref_get(&mgr->mst_primary->kref);
2064
2065                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2066                                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2067                 if (ret < 0) {
2068                         goto out_unlock;
2069                 }
2070
2071                 {
2072                         struct drm_dp_payload reset_pay;
2073                         reset_pay.start_slot = 0;
2074                         reset_pay.num_slots = 0x3f;
2075                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2076                 }
2077
2078                 queue_work(system_long_wq, &mgr->work);
2079
2080                 ret = 0;
2081         } else {
2082                 /* disable MST on the device */
2083                 mstb = mgr->mst_primary;
2084                 mgr->mst_primary = NULL;
2085                 /* this can fail if the device is gone */
2086                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2087                 ret = 0;
2088                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2089                 mgr->payload_mask = 0;
2090                 set_bit(0, &mgr->payload_mask);
2091                 mgr->vcpi_mask = 0;
2092         }
2093
2094 out_unlock:
2095         mutex_unlock(&mgr->lock);
2096         if (mstb)
2097                 drm_dp_put_mst_branch_device(mstb);
2098         return ret;
2099
2100 }
2101 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2102
2103 /**
2104  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2105  * @mgr: manager to suspend
2106  *
2107  * This function tells the MST device that we can't handle UP messages
2108  * anymore. This should stop it from sending any since we are suspended.
2109  */
2110 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2111 {
2112         mutex_lock(&mgr->lock);
2113         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2114                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2115         mutex_unlock(&mgr->lock);
2116         flush_work(&mgr->work);
2117         flush_work(&mgr->destroy_connector_work);
2118 }
2119 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2120
2121 /**
2122  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2123  * @mgr: manager to resume
2124  *
2125  * This will fetch DPCD and see if the device is still there,
2126  * if it is, it will rewrite the MSTM control bits, and return.
2127  *
2128  * if the device fails this returns -1, and the driver should do
2129  * a full MST reprobe, in case we were undocked.
2130  */
2131 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2132 {
2133         int ret = 0;
2134
2135         mutex_lock(&mgr->lock);
2136
2137         if (mgr->mst_primary) {
2138                 int sret;
2139                 u8 guid[16];
2140
2141                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2142                 if (sret != DP_RECEIVER_CAP_SIZE) {
2143                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2144                         ret = -1;
2145                         goto out_unlock;
2146                 }
2147
2148                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2149                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2150                 if (ret < 0) {
2151                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2152                         ret = -1;
2153                         goto out_unlock;
2154                 }
2155
2156                 /* Some hubs forget their guids after they resume */
2157                 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2158                 if (sret != 16) {
2159                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2160                         ret = -1;
2161                         goto out_unlock;
2162                 }
2163                 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2164
2165                 ret = 0;
2166         } else
2167                 ret = -1;
2168
2169 out_unlock:
2170         mutex_unlock(&mgr->lock);
2171         return ret;
2172 }
2173 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2174
2175 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2176 {
2177         int len;
2178         u8 replyblock[32];
2179         int replylen, origlen, curreply;
2180         int ret;
2181         struct drm_dp_sideband_msg_rx *msg;
2182         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2183         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2184
2185         len = min(mgr->max_dpcd_transaction_bytes, 16);
2186         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2187                                replyblock, len);
2188         if (ret != len) {
2189                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2190                 return;
2191         }
2192         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2193         if (!ret) {
2194                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2195                 return;
2196         }
2197         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2198
2199         origlen = replylen;
2200         replylen -= len;
2201         curreply = len;
2202         while (replylen > 0) {
2203                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2204                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2205                                     replyblock, len);
2206                 if (ret != len) {
2207                         DRM_DEBUG_KMS("failed to read a chunk\n");
2208                 }
2209                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2210                 if (ret == false)
2211                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2212                 curreply += len;
2213                 replylen -= len;
2214         }
2215 }
2216
2217 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2218 {
2219         int ret = 0;
2220
2221         drm_dp_get_one_sb_msg(mgr, false);
2222
2223         if (mgr->down_rep_recv.have_eomt) {
2224                 struct drm_dp_sideband_msg_tx *txmsg;
2225                 struct drm_dp_mst_branch *mstb;
2226                 int slot = -1;
2227                 mstb = drm_dp_get_mst_branch_device(mgr,
2228                                                     mgr->down_rep_recv.initial_hdr.lct,
2229                                                     mgr->down_rep_recv.initial_hdr.rad);
2230
2231                 if (!mstb) {
2232                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2233                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2234                         return 0;
2235                 }
2236
2237                 /* find the message */
2238                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2239                 mutex_lock(&mgr->qlock);
2240                 txmsg = mstb->tx_slots[slot];
2241                 /* remove from slots */
2242                 mutex_unlock(&mgr->qlock);
2243
2244                 if (!txmsg) {
2245                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2246                                mstb,
2247                                mgr->down_rep_recv.initial_hdr.seqno,
2248                                mgr->down_rep_recv.initial_hdr.lct,
2249                                       mgr->down_rep_recv.initial_hdr.rad[0],
2250                                       mgr->down_rep_recv.msg[0]);
2251                         drm_dp_put_mst_branch_device(mstb);
2252                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2253                         return 0;
2254                 }
2255
2256                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2257                 if (txmsg->reply.reply_type == 1) {
2258                         DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
2259                 }
2260
2261                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2262                 drm_dp_put_mst_branch_device(mstb);
2263
2264                 mutex_lock(&mgr->qlock);
2265                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2266                 mstb->tx_slots[slot] = NULL;
2267                 mutex_unlock(&mgr->qlock);
2268
2269                 wake_up(&mgr->tx_waitq);
2270         }
2271         return ret;
2272 }
2273
2274 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2275 {
2276         int ret = 0;
2277         drm_dp_get_one_sb_msg(mgr, true);
2278
2279         if (mgr->up_req_recv.have_eomt) {
2280                 struct drm_dp_sideband_msg_req_body msg;
2281                 struct drm_dp_mst_branch *mstb = NULL;
2282                 bool seqno;
2283
2284                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2285                         mstb = drm_dp_get_mst_branch_device(mgr,
2286                                                             mgr->up_req_recv.initial_hdr.lct,
2287                                                             mgr->up_req_recv.initial_hdr.rad);
2288                         if (!mstb) {
2289                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2290                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2291                                 return 0;
2292                         }
2293                 }
2294
2295                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2296                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2297
2298                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2299                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2300
2301                         if (!mstb)
2302                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2303
2304                         if (!mstb) {
2305                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2306                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2307                                 return 0;
2308                         }
2309
2310                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2311
2312                         DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
2313                         (*mgr->cbs->hotplug)(mgr);
2314
2315                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2316                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2317                         if (!mstb)
2318                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2319
2320                         if (!mstb) {
2321                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2322                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2323                                 return 0;
2324                         }
2325
2326                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2327                 }
2328
2329                 drm_dp_put_mst_branch_device(mstb);
2330                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2331         }
2332         return ret;
2333 }
2334
2335 /**
2336  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2337  * @mgr: manager to notify irq for.
2338  * @esi: 4 bytes from SINK_COUNT_ESI
2339  * @handled: whether the hpd interrupt was consumed or not
2340  *
2341  * This should be called from the driver when it detects a short IRQ,
2342  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2343  * topology manager will process the sideband messages received as a result
2344  * of this.
2345  */
2346 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2347 {
2348         int ret = 0;
2349         int sc;
2350         *handled = false;
2351         sc = esi[0] & 0x3f;
2352
2353         if (sc != mgr->sink_count) {
2354                 mgr->sink_count = sc;
2355                 *handled = true;
2356         }
2357
2358         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2359                 ret = drm_dp_mst_handle_down_rep(mgr);
2360                 *handled = true;
2361         }
2362
2363         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2364                 ret |= drm_dp_mst_handle_up_req(mgr);
2365                 *handled = true;
2366         }
2367
2368         drm_dp_mst_kick_tx(mgr);
2369         return ret;
2370 }
2371 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2372
2373 /**
2374  * drm_dp_mst_detect_port() - get connection status for an MST port
2375  * @mgr: manager for this port
2376  * @port: unverified pointer to a port
2377  *
2378  * This returns the current connection state for a port. It validates the
2379  * port pointer still exists so the caller doesn't require a reference
2380  */
2381 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2382                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2383 {
2384         enum drm_connector_status status = connector_status_disconnected;
2385
2386         /* we need to search for the port in the mgr in case its gone */
2387         port = drm_dp_get_validated_port_ref(mgr, port);
2388         if (!port)
2389                 return connector_status_disconnected;
2390
2391         if (!port->ddps)
2392                 goto out;
2393
2394         switch (port->pdt) {
2395         case DP_PEER_DEVICE_NONE:
2396         case DP_PEER_DEVICE_MST_BRANCHING:
2397                 break;
2398
2399         case DP_PEER_DEVICE_SST_SINK:
2400                 status = connector_status_connected;
2401                 /* for logical ports - cache the EDID */
2402                 if (port->port_num >= 8 && !port->cached_edid) {
2403                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2404                 }
2405                 break;
2406         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2407                 if (port->ldps)
2408                         status = connector_status_connected;
2409                 break;
2410         }
2411 out:
2412         drm_dp_put_port(port);
2413         return status;
2414 }
2415 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2416
2417 /**
2418  * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2419  * @mgr: manager for this port
2420  * @port: unverified pointer to a port.
2421  *
2422  * This returns whether the port supports audio or not.
2423  */
2424 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2425                                         struct drm_dp_mst_port *port)
2426 {
2427         bool ret = false;
2428
2429         port = drm_dp_get_validated_port_ref(mgr, port);
2430         if (!port)
2431                 return ret;
2432         ret = port->has_audio;
2433         drm_dp_put_port(port);
2434         return ret;
2435 }
2436 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2437
2438 /**
2439  * drm_dp_mst_get_edid() - get EDID for an MST port
2440  * @connector: toplevel connector to get EDID for
2441  * @mgr: manager for this port
2442  * @port: unverified pointer to a port.
2443  *
2444  * This returns an EDID for the port connected to a connector,
2445  * It validates the pointer still exists so the caller doesn't require a
2446  * reference.
2447  */
2448 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2449 {
2450         struct edid *edid = NULL;
2451
2452         /* we need to search for the port in the mgr in case its gone */
2453         port = drm_dp_get_validated_port_ref(mgr, port);
2454         if (!port)
2455                 return NULL;
2456
2457         if (port->cached_edid)
2458                 edid = drm_edid_duplicate(port->cached_edid);
2459         else {
2460                 edid = drm_get_edid(connector, &port->aux.ddc);
2461                 drm_mode_connector_set_tile_property(connector);
2462         }
2463         port->has_audio = drm_detect_monitor_audio(edid);
2464         drm_dp_put_port(port);
2465         return edid;
2466 }
2467 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2468
2469 /**
2470  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2471  * @mgr: manager to use
2472  * @pbn: payload bandwidth to convert into slots.
2473  */
2474 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2475                            int pbn)
2476 {
2477         int num_slots;
2478
2479         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2480
2481         if (num_slots > mgr->avail_slots)
2482                 return -ENOSPC;
2483         return num_slots;
2484 }
2485 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2486
2487 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2488                             struct drm_dp_vcpi *vcpi, int pbn)
2489 {
2490         int num_slots;
2491         int ret;
2492
2493         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2494
2495         if (num_slots > mgr->avail_slots)
2496                 return -ENOSPC;
2497
2498         vcpi->pbn = pbn;
2499         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2500         vcpi->num_slots = num_slots;
2501
2502         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2503         if (ret < 0)
2504                 return ret;
2505         return 0;
2506 }
2507
2508 /**
2509  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2510  * @mgr: manager for this port
2511  * @port: port to allocate a virtual channel for.
2512  * @pbn: payload bandwidth number to request
2513  * @slots: returned number of slots for this PBN.
2514  */
2515 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2516 {
2517         int ret;
2518
2519         port = drm_dp_get_validated_port_ref(mgr, port);
2520         if (!port)
2521                 return false;
2522
2523         if (port->vcpi.vcpi > 0) {
2524                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2525                 if (pbn == port->vcpi.pbn) {
2526                         *slots = port->vcpi.num_slots;
2527                         drm_dp_put_port(port);
2528                         return true;
2529                 }
2530         }
2531
2532         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2533         if (ret) {
2534                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2535                 goto out;
2536         }
2537         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2538         *slots = port->vcpi.num_slots;
2539
2540         drm_dp_put_port(port);
2541         return true;
2542 out:
2543         return false;
2544 }
2545 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2546
2547 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2548 {
2549         int slots = 0;
2550         port = drm_dp_get_validated_port_ref(mgr, port);
2551         if (!port)
2552                 return slots;
2553
2554         slots = port->vcpi.num_slots;
2555         drm_dp_put_port(port);
2556         return slots;
2557 }
2558 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2559
2560 /**
2561  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2562  * @mgr: manager for this port
2563  * @port: unverified pointer to a port.
2564  *
2565  * This just resets the number of slots for the ports VCPI for later programming.
2566  */
2567 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2568 {
2569         port = drm_dp_get_validated_port_ref(mgr, port);
2570         if (!port)
2571                 return;
2572         port->vcpi.num_slots = 0;
2573         drm_dp_put_port(port);
2574 }
2575 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2576
2577 /**
2578  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2579  * @mgr: manager for this port
2580  * @port: unverified port to deallocate vcpi for
2581  */
2582 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2583 {
2584         port = drm_dp_get_validated_port_ref(mgr, port);
2585         if (!port)
2586                 return;
2587
2588         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2589         port->vcpi.num_slots = 0;
2590         port->vcpi.pbn = 0;
2591         port->vcpi.aligned_pbn = 0;
2592         port->vcpi.vcpi = 0;
2593         drm_dp_put_port(port);
2594 }
2595 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2596
2597 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2598                                      int id, struct drm_dp_payload *payload)
2599 {
2600         u8 payload_alloc[3], status;
2601         int ret;
2602         int retries = 0;
2603
2604         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2605                            DP_PAYLOAD_TABLE_UPDATED);
2606
2607         payload_alloc[0] = id;
2608         payload_alloc[1] = payload->start_slot;
2609         payload_alloc[2] = payload->num_slots;
2610
2611         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2612         if (ret != 3) {
2613                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2614                 goto fail;
2615         }
2616
2617 retry:
2618         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2619         if (ret < 0) {
2620                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2621                 goto fail;
2622         }
2623
2624         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2625                 retries++;
2626                 if (retries < 20) {
2627                         usleep_range(10000, 20000);
2628                         goto retry;
2629                 }
2630                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2631                 ret = -EINVAL;
2632                 goto fail;
2633         }
2634         ret = 0;
2635 fail:
2636         return ret;
2637 }
2638
2639
2640 /**
2641  * drm_dp_check_act_status() - Check ACT handled status.
2642  * @mgr: manager to use
2643  *
2644  * Check the payload status bits in the DPCD for ACT handled completion.
2645  */
2646 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2647 {
2648         u8 status;
2649         int ret;
2650         int count = 0;
2651
2652         do {
2653                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2654
2655                 if (ret < 0) {
2656                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2657                         goto fail;
2658                 }
2659
2660                 if (status & DP_PAYLOAD_ACT_HANDLED)
2661                         break;
2662                 count++;
2663                 udelay(100);
2664
2665         } while (count < 30);
2666
2667         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2668                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2669                 ret = -EINVAL;
2670                 goto fail;
2671         }
2672         return 0;
2673 fail:
2674         return ret;
2675 }
2676 EXPORT_SYMBOL(drm_dp_check_act_status);
2677
2678 /**
2679  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2680  * @clock: dot clock for the mode
2681  * @bpp: bpp for the mode.
2682  *
2683  * This uses the formula in the spec to calculate the PBN value for a mode.
2684  */
2685 int drm_dp_calc_pbn_mode(int clock, int bpp)
2686 {
2687         u64 kbps;
2688         s64 peak_kbps;
2689         u32 numerator;
2690         u32 denominator;
2691
2692         kbps = clock * bpp;
2693
2694         /*
2695          * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2696          * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2697          * common multiplier to render an integer PBN for all link rate/lane
2698          * counts combinations
2699          * calculate
2700          * peak_kbps *= (1006/1000)
2701          * peak_kbps *= (64/54)
2702          * peak_kbps *= 8    convert to bytes
2703          */
2704
2705         numerator = 64 * 1006;
2706         denominator = 54 * 8 * 1000 * 1000;
2707
2708         kbps *= numerator;
2709         peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2710
2711         return drm_fixp2int_ceil(peak_kbps);
2712 }
2713 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2714
2715 static int test_calc_pbn_mode(void)
2716 {
2717         int ret;
2718         ret = drm_dp_calc_pbn_mode(154000, 30);
2719         if (ret != 689) {
2720                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2721                                 154000, 30, 689, ret);
2722                 return -EINVAL;
2723         }
2724         ret = drm_dp_calc_pbn_mode(234000, 30);
2725         if (ret != 1047) {
2726                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2727                                 234000, 30, 1047, ret);
2728                 return -EINVAL;
2729         }
2730         ret = drm_dp_calc_pbn_mode(297000, 24);
2731         if (ret != 1063) {
2732                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2733                                 297000, 24, 1063, ret);
2734                 return -EINVAL;
2735         }
2736         return 0;
2737 }
2738
2739 /* we want to kick the TX after we've ack the up/down IRQs. */
2740 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2741 {
2742         queue_work(system_long_wq, &mgr->tx_work);
2743 }
2744
2745 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2746                                  struct drm_dp_mst_branch *mstb)
2747 {
2748         struct drm_dp_mst_port *port;
2749         int tabs = mstb->lct;
2750         char prefix[10];
2751         int i;
2752
2753         for (i = 0; i < tabs; i++)
2754                 prefix[i] = '\t';
2755         prefix[i] = '\0';
2756
2757         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2758         list_for_each_entry(port, &mstb->ports, next) {
2759                 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2760                 if (port->mstb)
2761                         drm_dp_mst_dump_mstb(m, port->mstb);
2762         }
2763 }
2764
2765 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2766                                   char *buf)
2767 {
2768         int ret;
2769         int i;
2770         for (i = 0; i < 4; i++) {
2771                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2772                 if (ret != 16)
2773                         break;
2774         }
2775         if (i == 4)
2776                 return true;
2777         return false;
2778 }
2779
2780 /**
2781  * drm_dp_mst_dump_topology(): dump topology to seq file.
2782  * @m: seq_file to dump output to
2783  * @mgr: manager to dump current topology for.
2784  *
2785  * helper to dump MST topology to a seq file for debugfs.
2786  */
2787 void drm_dp_mst_dump_topology(struct seq_file *m,
2788                               struct drm_dp_mst_topology_mgr *mgr)
2789 {
2790         int i;
2791         struct drm_dp_mst_port *port;
2792         mutex_lock(&mgr->lock);
2793         if (mgr->mst_primary)
2794                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2795
2796         /* dump VCPIs */
2797         mutex_unlock(&mgr->lock);
2798
2799         mutex_lock(&mgr->payload_lock);
2800         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2801
2802         for (i = 0; i < mgr->max_payloads; i++) {
2803                 if (mgr->proposed_vcpis[i]) {
2804                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2805                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2806                 } else
2807                         seq_printf(m, "vcpi %d:unsed\n", i);
2808         }
2809         for (i = 0; i < mgr->max_payloads; i++) {
2810                 seq_printf(m, "payload %d: %d, %d, %d\n",
2811                            i,
2812                            mgr->payloads[i].payload_state,
2813                            mgr->payloads[i].start_slot,
2814                            mgr->payloads[i].num_slots);
2815
2816
2817         }
2818         mutex_unlock(&mgr->payload_lock);
2819
2820         mutex_lock(&mgr->lock);
2821         if (mgr->mst_primary) {
2822                 u8 buf[64];
2823                 bool bret;
2824                 int ret;
2825                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2826                 seq_printf(m, "dpcd: ");
2827                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2828                         seq_printf(m, "%02x ", buf[i]);
2829                 seq_printf(m, "\n");
2830                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2831                 seq_printf(m, "faux/mst: ");
2832                 for (i = 0; i < 2; i++)
2833                         seq_printf(m, "%02x ", buf[i]);
2834                 seq_printf(m, "\n");
2835                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2836                 seq_printf(m, "mst ctrl: ");
2837                 for (i = 0; i < 1; i++)
2838                         seq_printf(m, "%02x ", buf[i]);
2839                 seq_printf(m, "\n");
2840
2841                 /* dump the standard OUI branch header */
2842                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2843                 seq_printf(m, "branch oui: ");
2844                 for (i = 0; i < 0x3; i++)
2845                         seq_printf(m, "%02x", buf[i]);
2846                 seq_printf(m, " devid: ");
2847                 for (i = 0x3; i < 0x8; i++)
2848                         seq_printf(m, "%c", buf[i]);
2849                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2850                 seq_printf(m, "\n");
2851                 bret = dump_dp_payload_table(mgr, buf);
2852                 if (bret == true) {
2853                         seq_printf(m, "payload table: ");
2854                         for (i = 0; i < 63; i++)
2855                                 seq_printf(m, "%02x ", buf[i]);
2856                         seq_printf(m, "\n");
2857                 }
2858
2859         }
2860
2861         mutex_unlock(&mgr->lock);
2862
2863 }
2864 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2865
2866 static void drm_dp_tx_work(struct work_struct *work)
2867 {
2868         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2869
2870         mutex_lock(&mgr->qlock);
2871         if (mgr->tx_down_in_progress)
2872                 process_single_down_tx_qlock(mgr);
2873         mutex_unlock(&mgr->qlock);
2874 }
2875
2876 static void drm_dp_free_mst_port(struct kref *kref)
2877 {
2878         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2879         kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2880         kfree(port);
2881 }
2882
2883 static void drm_dp_destroy_connector_work(struct work_struct *work)
2884 {
2885         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2886         struct drm_dp_mst_port *port;
2887         bool send_hotplug = false;
2888         /*
2889          * Not a regular list traverse as we have to drop the destroy
2890          * connector lock before destroying the connector, to avoid AB->BA
2891          * ordering between this lock and the config mutex.
2892          */
2893         for (;;) {
2894                 mutex_lock(&mgr->destroy_connector_lock);
2895                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2896                 if (!port) {
2897                         mutex_unlock(&mgr->destroy_connector_lock);
2898                         break;
2899                 }
2900                 list_del(&port->next);
2901                 mutex_unlock(&mgr->destroy_connector_lock);
2902
2903                 kref_init(&port->kref);
2904                 INIT_LIST_HEAD(&port->next);
2905
2906                 mgr->cbs->destroy_connector(mgr, port->connector);
2907
2908                 drm_dp_port_teardown_pdt(port, port->pdt);
2909
2910                 if (!port->input && port->vcpi.vcpi > 0) {
2911                         if (mgr->mst_state) {
2912                                 drm_dp_mst_reset_vcpi_slots(mgr, port);
2913                                 drm_dp_update_payload_part1(mgr);
2914                                 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2915                         }
2916                 }
2917
2918                 kref_put(&port->kref, drm_dp_free_mst_port);
2919                 send_hotplug = true;
2920         }
2921         if (send_hotplug)
2922                 (*mgr->cbs->hotplug)(mgr);
2923 }
2924
2925 /**
2926  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2927  * @mgr: manager struct to initialise
2928  * @dev: device providing this structure - for i2c addition.
2929  * @aux: DP helper aux channel to talk to this device
2930  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2931  * @max_payloads: maximum number of payloads this GPU can source
2932  * @conn_base_id: the connector object ID the MST device is connected to.
2933  *
2934  * Return 0 for success, or negative error code on failure
2935  */
2936 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2937                                  struct device *dev, struct drm_dp_aux *aux,
2938                                  int max_dpcd_transaction_bytes,
2939                                  int max_payloads, int conn_base_id)
2940 {
2941         mutex_init(&mgr->lock);
2942         mutex_init(&mgr->qlock);
2943         mutex_init(&mgr->payload_lock);
2944         mutex_init(&mgr->destroy_connector_lock);
2945         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2946         INIT_LIST_HEAD(&mgr->destroy_connector_list);
2947         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2948         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2949         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2950         init_waitqueue_head(&mgr->tx_waitq);
2951         mgr->dev = dev;
2952         mgr->aux = aux;
2953         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2954         mgr->max_payloads = max_payloads;
2955         mgr->conn_base_id = conn_base_id;
2956         if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
2957             max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
2958                 return -EINVAL;
2959         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2960         if (!mgr->payloads)
2961                 return -ENOMEM;
2962         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2963         if (!mgr->proposed_vcpis)
2964                 return -ENOMEM;
2965         set_bit(0, &mgr->payload_mask);
2966         if (test_calc_pbn_mode() < 0)
2967                 DRM_ERROR("MST PBN self-test failed\n");
2968
2969         return 0;
2970 }
2971 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2972
2973 /**
2974  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2975  * @mgr: manager to destroy
2976  */
2977 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2978 {
2979         flush_work(&mgr->work);
2980         flush_work(&mgr->destroy_connector_work);
2981         mutex_lock(&mgr->payload_lock);
2982         kfree(mgr->payloads);
2983         mgr->payloads = NULL;
2984         kfree(mgr->proposed_vcpis);
2985         mgr->proposed_vcpis = NULL;
2986         mutex_unlock(&mgr->payload_lock);
2987         mgr->dev = NULL;
2988         mgr->aux = NULL;
2989 }
2990 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2991
2992 /* I2C device */
2993 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2994                                int num)
2995 {
2996         struct drm_dp_aux *aux = adapter->algo_data;
2997         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2998         struct drm_dp_mst_branch *mstb;
2999         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3000         unsigned int i;
3001         bool reading = false;
3002         struct drm_dp_sideband_msg_req_body msg;
3003         struct drm_dp_sideband_msg_tx *txmsg = NULL;
3004         int ret;
3005
3006         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3007         if (!mstb)
3008                 return -EREMOTEIO;
3009
3010         /* construct i2c msg */
3011         /* see if last msg is a read */
3012         if (msgs[num - 1].flags & I2C_M_RD)
3013                 reading = true;
3014
3015         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3016                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3017                 ret = -EIO;
3018                 goto out;
3019         }
3020
3021         memset(&msg, 0, sizeof(msg));
3022         msg.req_type = DP_REMOTE_I2C_READ;
3023         msg.u.i2c_read.num_transactions = num - 1;
3024         msg.u.i2c_read.port_number = port->port_num;
3025         for (i = 0; i < num - 1; i++) {
3026                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3027                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3028                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3029         }
3030         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3031         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3032
3033         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3034         if (!txmsg) {
3035                 ret = -ENOMEM;
3036                 goto out;
3037         }
3038
3039         txmsg->dst = mstb;
3040         drm_dp_encode_sideband_req(&msg, txmsg);
3041
3042         drm_dp_queue_down_tx(mgr, txmsg);
3043
3044         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3045         if (ret > 0) {
3046
3047                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3048                         ret = -EREMOTEIO;
3049                         goto out;
3050                 }
3051                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3052                         ret = -EIO;
3053                         goto out;
3054                 }
3055                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3056                 ret = num;
3057         }
3058 out:
3059         kfree(txmsg);
3060         drm_dp_put_mst_branch_device(mstb);
3061         return ret;
3062 }
3063
3064 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3065 {
3066         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3067                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3068                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3069                I2C_FUNC_10BIT_ADDR;
3070 }
3071
3072 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3073         .functionality = drm_dp_mst_i2c_functionality,
3074         .master_xfer = drm_dp_mst_i2c_xfer,
3075 };
3076
3077 /**
3078  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3079  * @aux: DisplayPort AUX channel
3080  *
3081  * Returns 0 on success or a negative error code on failure.
3082  */
3083 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3084 {
3085         aux->ddc.algo = &drm_dp_mst_i2c_algo;
3086         aux->ddc.algo_data = aux;
3087         aux->ddc.retries = 3;
3088
3089         aux->ddc.class = I2C_CLASS_DDC;
3090         aux->ddc.owner = THIS_MODULE;
3091         aux->ddc.dev.parent = aux->dev;
3092         aux->ddc.dev.of_node = aux->dev->of_node;
3093
3094         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3095                 sizeof(aux->ddc.name));
3096
3097         return i2c_add_adapter(&aux->ddc);
3098 }
3099
3100 /**
3101  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3102  * @aux: DisplayPort AUX channel
3103  */
3104 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3105 {
3106         i2c_del_adapter(&aux->ddc);
3107 }