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                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1800                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1801                 } else {
1802                         port = NULL;
1803                         req_payload.num_slots = 0;
1804                 }
1805
1806                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1807                         mgr->payloads[i].start_slot = req_payload.start_slot;
1808                 }
1809                 /* work out what is required to happen with this payload */
1810                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1811
1812                         /* need to push an update for this payload */
1813                         if (req_payload.num_slots) {
1814                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1815                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1816                                 mgr->payloads[i].vcpi = req_payload.vcpi;
1817                         } else if (mgr->payloads[i].num_slots) {
1818                                 mgr->payloads[i].num_slots = 0;
1819                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1820                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1821                                 mgr->payloads[i].start_slot = 0;
1822                         }
1823                         mgr->payloads[i].payload_state = req_payload.payload_state;
1824                 }
1825                 cur_slots += req_payload.num_slots;
1826         }
1827
1828         for (i = 0; i < mgr->max_payloads; i++) {
1829                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1830                         DRM_DEBUG_KMS("removing payload %d\n", i);
1831                         for (j = i; j < mgr->max_payloads - 1; j++) {
1832                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1833                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1834                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1835                                         set_bit(j + 1, &mgr->payload_mask);
1836                                 } else {
1837                                         clear_bit(j + 1, &mgr->payload_mask);
1838                                 }
1839                         }
1840                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1841                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1842                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1843
1844                 }
1845         }
1846         mutex_unlock(&mgr->payload_lock);
1847
1848         return 0;
1849 }
1850 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1851
1852 /**
1853  * drm_dp_update_payload_part2() - Execute payload update part 2
1854  * @mgr: manager to use.
1855  *
1856  * This iterates over all proposed virtual channels, and tries to
1857  * allocate space in the link for them. For 0->slots transitions,
1858  * this step writes the remote VC payload commands. For slots->0
1859  * this just resets some internal state.
1860  */
1861 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1862 {
1863         struct drm_dp_mst_port *port;
1864         int i;
1865         int ret = 0;
1866         mutex_lock(&mgr->payload_lock);
1867         for (i = 0; i < mgr->max_payloads; i++) {
1868
1869                 if (!mgr->proposed_vcpis[i])
1870                         continue;
1871
1872                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1873
1874                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1875                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1876                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1877                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1878                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1879                 }
1880                 if (ret) {
1881                         mutex_unlock(&mgr->payload_lock);
1882                         return ret;
1883                 }
1884         }
1885         mutex_unlock(&mgr->payload_lock);
1886         return 0;
1887 }
1888 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1889
1890 #if 0 /* unused as of yet */
1891 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1892                                  struct drm_dp_mst_port *port,
1893                                  int offset, int size)
1894 {
1895         int len;
1896         struct drm_dp_sideband_msg_tx *txmsg;
1897
1898         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1899         if (!txmsg)
1900                 return -ENOMEM;
1901
1902         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1903         txmsg->dst = port->parent;
1904
1905         drm_dp_queue_down_tx(mgr, txmsg);
1906
1907         return 0;
1908 }
1909 #endif
1910
1911 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1912                                   struct drm_dp_mst_port *port,
1913                                   int offset, int size, u8 *bytes)
1914 {
1915         int len;
1916         int ret;
1917         struct drm_dp_sideband_msg_tx *txmsg;
1918         struct drm_dp_mst_branch *mstb;
1919
1920         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1921         if (!mstb)
1922                 return -EINVAL;
1923
1924         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1925         if (!txmsg) {
1926                 ret = -ENOMEM;
1927                 goto fail_put;
1928         }
1929
1930         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1931         txmsg->dst = mstb;
1932
1933         drm_dp_queue_down_tx(mgr, txmsg);
1934
1935         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1936         if (ret > 0) {
1937                 if (txmsg->reply.reply_type == 1) {
1938                         ret = -EINVAL;
1939                 } else
1940                         ret = 0;
1941         }
1942         kfree(txmsg);
1943 fail_put:
1944         drm_dp_put_mst_branch_device(mstb);
1945         return ret;
1946 }
1947
1948 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1949 {
1950         struct drm_dp_sideband_msg_reply_body reply;
1951
1952         reply.reply_type = 0;
1953         reply.req_type = req_type;
1954         drm_dp_encode_sideband_reply(&reply, msg);
1955         return 0;
1956 }
1957
1958 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1959                                     struct drm_dp_mst_branch *mstb,
1960                                     int req_type, int seqno, bool broadcast)
1961 {
1962         struct drm_dp_sideband_msg_tx *txmsg;
1963
1964         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1965         if (!txmsg)
1966                 return -ENOMEM;
1967
1968         txmsg->dst = mstb;
1969         txmsg->seqno = seqno;
1970         drm_dp_encode_up_ack_reply(txmsg, req_type);
1971
1972         mutex_lock(&mgr->qlock);
1973
1974         process_single_up_tx_qlock(mgr, txmsg);
1975
1976         mutex_unlock(&mgr->qlock);
1977
1978         kfree(txmsg);
1979         return 0;
1980 }
1981
1982 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1983                                      int dp_link_count,
1984                                      int *out)
1985 {
1986         switch (dp_link_bw) {
1987         default:
1988                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1989                               dp_link_bw, dp_link_count);
1990                 return false;
1991
1992         case DP_LINK_BW_1_62:
1993                 *out = 3 * dp_link_count;
1994                 break;
1995         case DP_LINK_BW_2_7:
1996                 *out = 5 * dp_link_count;
1997                 break;
1998         case DP_LINK_BW_5_4:
1999                 *out = 10 * dp_link_count;
2000                 break;
2001         }
2002         return true;
2003 }
2004
2005 /**
2006  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2007  * @mgr: manager to set state for
2008  * @mst_state: true to enable MST on this connector - false to disable.
2009  *
2010  * This is called by the driver when it detects an MST capable device plugged
2011  * into a DP MST capable port, or when a DP MST capable device is unplugged.
2012  */
2013 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2014 {
2015         int ret = 0;
2016         struct drm_dp_mst_branch *mstb = NULL;
2017
2018         mutex_lock(&mgr->lock);
2019         if (mst_state == mgr->mst_state)
2020                 goto out_unlock;
2021
2022         mgr->mst_state = mst_state;
2023         /* set the device into MST mode */
2024         if (mst_state) {
2025                 WARN_ON(mgr->mst_primary);
2026
2027                 /* get dpcd info */
2028                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2029                 if (ret != DP_RECEIVER_CAP_SIZE) {
2030                         DRM_DEBUG_KMS("failed to read DPCD\n");
2031                         goto out_unlock;
2032                 }
2033
2034                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2035                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2036                                               &mgr->pbn_div)) {
2037                         ret = -EINVAL;
2038                         goto out_unlock;
2039                 }
2040
2041                 mgr->total_pbn = 2560;
2042                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2043                 mgr->avail_slots = mgr->total_slots;
2044
2045                 /* add initial branch device at LCT 1 */
2046                 mstb = drm_dp_add_mst_branch_device(1, NULL);
2047                 if (mstb == NULL) {
2048                         ret = -ENOMEM;
2049                         goto out_unlock;
2050                 }
2051                 mstb->mgr = mgr;
2052
2053                 /* give this the main reference */
2054                 mgr->mst_primary = mstb;
2055                 kref_get(&mgr->mst_primary->kref);
2056
2057                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2058                                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2059                 if (ret < 0) {
2060                         goto out_unlock;
2061                 }
2062
2063                 {
2064                         struct drm_dp_payload reset_pay;
2065                         reset_pay.start_slot = 0;
2066                         reset_pay.num_slots = 0x3f;
2067                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2068                 }
2069
2070                 queue_work(system_long_wq, &mgr->work);
2071
2072                 ret = 0;
2073         } else {
2074                 /* disable MST on the device */
2075                 mstb = mgr->mst_primary;
2076                 mgr->mst_primary = NULL;
2077                 /* this can fail if the device is gone */
2078                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2079                 ret = 0;
2080                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2081                 mgr->payload_mask = 0;
2082                 set_bit(0, &mgr->payload_mask);
2083                 mgr->vcpi_mask = 0;
2084         }
2085
2086 out_unlock:
2087         mutex_unlock(&mgr->lock);
2088         if (mstb)
2089                 drm_dp_put_mst_branch_device(mstb);
2090         return ret;
2091
2092 }
2093 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2094
2095 /**
2096  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2097  * @mgr: manager to suspend
2098  *
2099  * This function tells the MST device that we can't handle UP messages
2100  * anymore. This should stop it from sending any since we are suspended.
2101  */
2102 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2103 {
2104         mutex_lock(&mgr->lock);
2105         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2106                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2107         mutex_unlock(&mgr->lock);
2108         flush_work(&mgr->work);
2109         flush_work(&mgr->destroy_connector_work);
2110 }
2111 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2112
2113 /**
2114  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2115  * @mgr: manager to resume
2116  *
2117  * This will fetch DPCD and see if the device is still there,
2118  * if it is, it will rewrite the MSTM control bits, and return.
2119  *
2120  * if the device fails this returns -1, and the driver should do
2121  * a full MST reprobe, in case we were undocked.
2122  */
2123 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2124 {
2125         int ret = 0;
2126
2127         mutex_lock(&mgr->lock);
2128
2129         if (mgr->mst_primary) {
2130                 int sret;
2131                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2132                 if (sret != DP_RECEIVER_CAP_SIZE) {
2133                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2134                         ret = -1;
2135                         goto out_unlock;
2136                 }
2137
2138                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2139                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2140                 if (ret < 0) {
2141                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2142                         ret = -1;
2143                         goto out_unlock;
2144                 }
2145                 ret = 0;
2146         } else
2147                 ret = -1;
2148
2149 out_unlock:
2150         mutex_unlock(&mgr->lock);
2151         return ret;
2152 }
2153 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2154
2155 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2156 {
2157         int len;
2158         u8 replyblock[32];
2159         int replylen, origlen, curreply;
2160         int ret;
2161         struct drm_dp_sideband_msg_rx *msg;
2162         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2163         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2164
2165         len = min(mgr->max_dpcd_transaction_bytes, 16);
2166         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2167                                replyblock, len);
2168         if (ret != len) {
2169                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2170                 return;
2171         }
2172         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2173         if (!ret) {
2174                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2175                 return;
2176         }
2177         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2178
2179         origlen = replylen;
2180         replylen -= len;
2181         curreply = len;
2182         while (replylen > 0) {
2183                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2184                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2185                                     replyblock, len);
2186                 if (ret != len) {
2187                         DRM_DEBUG_KMS("failed to read a chunk\n");
2188                 }
2189                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2190                 if (ret == false)
2191                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2192                 curreply += len;
2193                 replylen -= len;
2194         }
2195 }
2196
2197 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2198 {
2199         int ret = 0;
2200
2201         drm_dp_get_one_sb_msg(mgr, false);
2202
2203         if (mgr->down_rep_recv.have_eomt) {
2204                 struct drm_dp_sideband_msg_tx *txmsg;
2205                 struct drm_dp_mst_branch *mstb;
2206                 int slot = -1;
2207                 mstb = drm_dp_get_mst_branch_device(mgr,
2208                                                     mgr->down_rep_recv.initial_hdr.lct,
2209                                                     mgr->down_rep_recv.initial_hdr.rad);
2210
2211                 if (!mstb) {
2212                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2213                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2214                         return 0;
2215                 }
2216
2217                 /* find the message */
2218                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2219                 mutex_lock(&mgr->qlock);
2220                 txmsg = mstb->tx_slots[slot];
2221                 /* remove from slots */
2222                 mutex_unlock(&mgr->qlock);
2223
2224                 if (!txmsg) {
2225                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2226                                mstb,
2227                                mgr->down_rep_recv.initial_hdr.seqno,
2228                                mgr->down_rep_recv.initial_hdr.lct,
2229                                       mgr->down_rep_recv.initial_hdr.rad[0],
2230                                       mgr->down_rep_recv.msg[0]);
2231                         drm_dp_put_mst_branch_device(mstb);
2232                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2233                         return 0;
2234                 }
2235
2236                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2237                 if (txmsg->reply.reply_type == 1) {
2238                         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);
2239                 }
2240
2241                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2242                 drm_dp_put_mst_branch_device(mstb);
2243
2244                 mutex_lock(&mgr->qlock);
2245                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2246                 mstb->tx_slots[slot] = NULL;
2247                 mutex_unlock(&mgr->qlock);
2248
2249                 wake_up(&mgr->tx_waitq);
2250         }
2251         return ret;
2252 }
2253
2254 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2255 {
2256         int ret = 0;
2257         drm_dp_get_one_sb_msg(mgr, true);
2258
2259         if (mgr->up_req_recv.have_eomt) {
2260                 struct drm_dp_sideband_msg_req_body msg;
2261                 struct drm_dp_mst_branch *mstb = NULL;
2262                 bool seqno;
2263
2264                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2265                         mstb = drm_dp_get_mst_branch_device(mgr,
2266                                                             mgr->up_req_recv.initial_hdr.lct,
2267                                                             mgr->up_req_recv.initial_hdr.rad);
2268                         if (!mstb) {
2269                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2270                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2271                                 return 0;
2272                         }
2273                 }
2274
2275                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2276                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2277
2278                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2279                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2280
2281                         if (!mstb)
2282                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2283
2284                         if (!mstb) {
2285                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2286                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2287                                 return 0;
2288                         }
2289
2290                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2291
2292                         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);
2293                         (*mgr->cbs->hotplug)(mgr);
2294
2295                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2296                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2297                         if (!mstb)
2298                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2299
2300                         if (!mstb) {
2301                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2302                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2303                                 return 0;
2304                         }
2305
2306                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2307                 }
2308
2309                 drm_dp_put_mst_branch_device(mstb);
2310                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2311         }
2312         return ret;
2313 }
2314
2315 /**
2316  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2317  * @mgr: manager to notify irq for.
2318  * @esi: 4 bytes from SINK_COUNT_ESI
2319  * @handled: whether the hpd interrupt was consumed or not
2320  *
2321  * This should be called from the driver when it detects a short IRQ,
2322  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2323  * topology manager will process the sideband messages received as a result
2324  * of this.
2325  */
2326 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2327 {
2328         int ret = 0;
2329         int sc;
2330         *handled = false;
2331         sc = esi[0] & 0x3f;
2332
2333         if (sc != mgr->sink_count) {
2334                 mgr->sink_count = sc;
2335                 *handled = true;
2336         }
2337
2338         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2339                 ret = drm_dp_mst_handle_down_rep(mgr);
2340                 *handled = true;
2341         }
2342
2343         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2344                 ret |= drm_dp_mst_handle_up_req(mgr);
2345                 *handled = true;
2346         }
2347
2348         drm_dp_mst_kick_tx(mgr);
2349         return ret;
2350 }
2351 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2352
2353 /**
2354  * drm_dp_mst_detect_port() - get connection status for an MST port
2355  * @mgr: manager for this port
2356  * @port: unverified pointer to a port
2357  *
2358  * This returns the current connection state for a port. It validates the
2359  * port pointer still exists so the caller doesn't require a reference
2360  */
2361 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2362                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2363 {
2364         enum drm_connector_status status = connector_status_disconnected;
2365
2366         /* we need to search for the port in the mgr in case its gone */
2367         port = drm_dp_get_validated_port_ref(mgr, port);
2368         if (!port)
2369                 return connector_status_disconnected;
2370
2371         if (!port->ddps)
2372                 goto out;
2373
2374         switch (port->pdt) {
2375         case DP_PEER_DEVICE_NONE:
2376         case DP_PEER_DEVICE_MST_BRANCHING:
2377                 break;
2378
2379         case DP_PEER_DEVICE_SST_SINK:
2380                 status = connector_status_connected;
2381                 /* for logical ports - cache the EDID */
2382                 if (port->port_num >= 8 && !port->cached_edid) {
2383                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2384                 }
2385                 break;
2386         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2387                 if (port->ldps)
2388                         status = connector_status_connected;
2389                 break;
2390         }
2391 out:
2392         drm_dp_put_port(port);
2393         return status;
2394 }
2395 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2396
2397 /**
2398  * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2399  * @mgr: manager for this port
2400  * @port: unverified pointer to a port.
2401  *
2402  * This returns whether the port supports audio or not.
2403  */
2404 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2405                                         struct drm_dp_mst_port *port)
2406 {
2407         bool ret = false;
2408
2409         port = drm_dp_get_validated_port_ref(mgr, port);
2410         if (!port)
2411                 return ret;
2412         ret = port->has_audio;
2413         drm_dp_put_port(port);
2414         return ret;
2415 }
2416 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2417
2418 /**
2419  * drm_dp_mst_get_edid() - get EDID for an MST port
2420  * @connector: toplevel connector to get EDID for
2421  * @mgr: manager for this port
2422  * @port: unverified pointer to a port.
2423  *
2424  * This returns an EDID for the port connected to a connector,
2425  * It validates the pointer still exists so the caller doesn't require a
2426  * reference.
2427  */
2428 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2429 {
2430         struct edid *edid = NULL;
2431
2432         /* we need to search for the port in the mgr in case its gone */
2433         port = drm_dp_get_validated_port_ref(mgr, port);
2434         if (!port)
2435                 return NULL;
2436
2437         if (port->cached_edid)
2438                 edid = drm_edid_duplicate(port->cached_edid);
2439         else {
2440                 edid = drm_get_edid(connector, &port->aux.ddc);
2441                 drm_mode_connector_set_tile_property(connector);
2442         }
2443         port->has_audio = drm_detect_monitor_audio(edid);
2444         drm_dp_put_port(port);
2445         return edid;
2446 }
2447 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2448
2449 /**
2450  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2451  * @mgr: manager to use
2452  * @pbn: payload bandwidth to convert into slots.
2453  */
2454 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2455                            int pbn)
2456 {
2457         int num_slots;
2458
2459         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2460
2461         if (num_slots > mgr->avail_slots)
2462                 return -ENOSPC;
2463         return num_slots;
2464 }
2465 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2466
2467 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2468                             struct drm_dp_vcpi *vcpi, int pbn)
2469 {
2470         int num_slots;
2471         int ret;
2472
2473         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2474
2475         if (num_slots > mgr->avail_slots)
2476                 return -ENOSPC;
2477
2478         vcpi->pbn = pbn;
2479         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2480         vcpi->num_slots = num_slots;
2481
2482         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2483         if (ret < 0)
2484                 return ret;
2485         return 0;
2486 }
2487
2488 /**
2489  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2490  * @mgr: manager for this port
2491  * @port: port to allocate a virtual channel for.
2492  * @pbn: payload bandwidth number to request
2493  * @slots: returned number of slots for this PBN.
2494  */
2495 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2496 {
2497         int ret;
2498
2499         port = drm_dp_get_validated_port_ref(mgr, port);
2500         if (!port)
2501                 return false;
2502
2503         if (port->vcpi.vcpi > 0) {
2504                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2505                 if (pbn == port->vcpi.pbn) {
2506                         *slots = port->vcpi.num_slots;
2507                         drm_dp_put_port(port);
2508                         return true;
2509                 }
2510         }
2511
2512         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2513         if (ret) {
2514                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2515                 goto out;
2516         }
2517         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2518         *slots = port->vcpi.num_slots;
2519
2520         drm_dp_put_port(port);
2521         return true;
2522 out:
2523         return false;
2524 }
2525 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2526
2527 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2528 {
2529         int slots = 0;
2530         port = drm_dp_get_validated_port_ref(mgr, port);
2531         if (!port)
2532                 return slots;
2533
2534         slots = port->vcpi.num_slots;
2535         drm_dp_put_port(port);
2536         return slots;
2537 }
2538 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2539
2540 /**
2541  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2542  * @mgr: manager for this port
2543  * @port: unverified pointer to a port.
2544  *
2545  * This just resets the number of slots for the ports VCPI for later programming.
2546  */
2547 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2548 {
2549         port = drm_dp_get_validated_port_ref(mgr, port);
2550         if (!port)
2551                 return;
2552         port->vcpi.num_slots = 0;
2553         drm_dp_put_port(port);
2554 }
2555 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2556
2557 /**
2558  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2559  * @mgr: manager for this port
2560  * @port: unverified port to deallocate vcpi for
2561  */
2562 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2563 {
2564         port = drm_dp_get_validated_port_ref(mgr, port);
2565         if (!port)
2566                 return;
2567
2568         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2569         port->vcpi.num_slots = 0;
2570         port->vcpi.pbn = 0;
2571         port->vcpi.aligned_pbn = 0;
2572         port->vcpi.vcpi = 0;
2573         drm_dp_put_port(port);
2574 }
2575 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2576
2577 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2578                                      int id, struct drm_dp_payload *payload)
2579 {
2580         u8 payload_alloc[3], status;
2581         int ret;
2582         int retries = 0;
2583
2584         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2585                            DP_PAYLOAD_TABLE_UPDATED);
2586
2587         payload_alloc[0] = id;
2588         payload_alloc[1] = payload->start_slot;
2589         payload_alloc[2] = payload->num_slots;
2590
2591         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2592         if (ret != 3) {
2593                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2594                 goto fail;
2595         }
2596
2597 retry:
2598         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2599         if (ret < 0) {
2600                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2601                 goto fail;
2602         }
2603
2604         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2605                 retries++;
2606                 if (retries < 20) {
2607                         usleep_range(10000, 20000);
2608                         goto retry;
2609                 }
2610                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2611                 ret = -EINVAL;
2612                 goto fail;
2613         }
2614         ret = 0;
2615 fail:
2616         return ret;
2617 }
2618
2619
2620 /**
2621  * drm_dp_check_act_status() - Check ACT handled status.
2622  * @mgr: manager to use
2623  *
2624  * Check the payload status bits in the DPCD for ACT handled completion.
2625  */
2626 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2627 {
2628         u8 status;
2629         int ret;
2630         int count = 0;
2631
2632         do {
2633                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2634
2635                 if (ret < 0) {
2636                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2637                         goto fail;
2638                 }
2639
2640                 if (status & DP_PAYLOAD_ACT_HANDLED)
2641                         break;
2642                 count++;
2643                 udelay(100);
2644
2645         } while (count < 30);
2646
2647         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2648                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2649                 ret = -EINVAL;
2650                 goto fail;
2651         }
2652         return 0;
2653 fail:
2654         return ret;
2655 }
2656 EXPORT_SYMBOL(drm_dp_check_act_status);
2657
2658 /**
2659  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2660  * @clock: dot clock for the mode
2661  * @bpp: bpp for the mode.
2662  *
2663  * This uses the formula in the spec to calculate the PBN value for a mode.
2664  */
2665 int drm_dp_calc_pbn_mode(int clock, int bpp)
2666 {
2667         u64 kbps;
2668         s64 peak_kbps;
2669         u32 numerator;
2670         u32 denominator;
2671
2672         kbps = clock * bpp;
2673
2674         /*
2675          * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2676          * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2677          * common multiplier to render an integer PBN for all link rate/lane
2678          * counts combinations
2679          * calculate
2680          * peak_kbps *= (1006/1000)
2681          * peak_kbps *= (64/54)
2682          * peak_kbps *= 8    convert to bytes
2683          */
2684
2685         numerator = 64 * 1006;
2686         denominator = 54 * 8 * 1000 * 1000;
2687
2688         kbps *= numerator;
2689         peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2690
2691         return drm_fixp2int_ceil(peak_kbps);
2692 }
2693 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2694
2695 static int test_calc_pbn_mode(void)
2696 {
2697         int ret;
2698         ret = drm_dp_calc_pbn_mode(154000, 30);
2699         if (ret != 689) {
2700                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2701                                 154000, 30, 689, ret);
2702                 return -EINVAL;
2703         }
2704         ret = drm_dp_calc_pbn_mode(234000, 30);
2705         if (ret != 1047) {
2706                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2707                                 234000, 30, 1047, ret);
2708                 return -EINVAL;
2709         }
2710         ret = drm_dp_calc_pbn_mode(297000, 24);
2711         if (ret != 1063) {
2712                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2713                                 297000, 24, 1063, ret);
2714                 return -EINVAL;
2715         }
2716         return 0;
2717 }
2718
2719 /* we want to kick the TX after we've ack the up/down IRQs. */
2720 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2721 {
2722         queue_work(system_long_wq, &mgr->tx_work);
2723 }
2724
2725 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2726                                  struct drm_dp_mst_branch *mstb)
2727 {
2728         struct drm_dp_mst_port *port;
2729         int tabs = mstb->lct;
2730         char prefix[10];
2731         int i;
2732
2733         for (i = 0; i < tabs; i++)
2734                 prefix[i] = '\t';
2735         prefix[i] = '\0';
2736
2737         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2738         list_for_each_entry(port, &mstb->ports, next) {
2739                 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);
2740                 if (port->mstb)
2741                         drm_dp_mst_dump_mstb(m, port->mstb);
2742         }
2743 }
2744
2745 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2746                                   char *buf)
2747 {
2748         int ret;
2749         int i;
2750         for (i = 0; i < 4; i++) {
2751                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2752                 if (ret != 16)
2753                         break;
2754         }
2755         if (i == 4)
2756                 return true;
2757         return false;
2758 }
2759
2760 /**
2761  * drm_dp_mst_dump_topology(): dump topology to seq file.
2762  * @m: seq_file to dump output to
2763  * @mgr: manager to dump current topology for.
2764  *
2765  * helper to dump MST topology to a seq file for debugfs.
2766  */
2767 void drm_dp_mst_dump_topology(struct seq_file *m,
2768                               struct drm_dp_mst_topology_mgr *mgr)
2769 {
2770         int i;
2771         struct drm_dp_mst_port *port;
2772         mutex_lock(&mgr->lock);
2773         if (mgr->mst_primary)
2774                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2775
2776         /* dump VCPIs */
2777         mutex_unlock(&mgr->lock);
2778
2779         mutex_lock(&mgr->payload_lock);
2780         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2781
2782         for (i = 0; i < mgr->max_payloads; i++) {
2783                 if (mgr->proposed_vcpis[i]) {
2784                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2785                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2786                 } else
2787                         seq_printf(m, "vcpi %d:unsed\n", i);
2788         }
2789         for (i = 0; i < mgr->max_payloads; i++) {
2790                 seq_printf(m, "payload %d: %d, %d, %d\n",
2791                            i,
2792                            mgr->payloads[i].payload_state,
2793                            mgr->payloads[i].start_slot,
2794                            mgr->payloads[i].num_slots);
2795
2796
2797         }
2798         mutex_unlock(&mgr->payload_lock);
2799
2800         mutex_lock(&mgr->lock);
2801         if (mgr->mst_primary) {
2802                 u8 buf[64];
2803                 bool bret;
2804                 int ret;
2805                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2806                 seq_printf(m, "dpcd: ");
2807                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2808                         seq_printf(m, "%02x ", buf[i]);
2809                 seq_printf(m, "\n");
2810                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2811                 seq_printf(m, "faux/mst: ");
2812                 for (i = 0; i < 2; i++)
2813                         seq_printf(m, "%02x ", buf[i]);
2814                 seq_printf(m, "\n");
2815                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2816                 seq_printf(m, "mst ctrl: ");
2817                 for (i = 0; i < 1; i++)
2818                         seq_printf(m, "%02x ", buf[i]);
2819                 seq_printf(m, "\n");
2820
2821                 /* dump the standard OUI branch header */
2822                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2823                 seq_printf(m, "branch oui: ");
2824                 for (i = 0; i < 0x3; i++)
2825                         seq_printf(m, "%02x", buf[i]);
2826                 seq_printf(m, " devid: ");
2827                 for (i = 0x3; i < 0x8; i++)
2828                         seq_printf(m, "%c", buf[i]);
2829                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2830                 seq_printf(m, "\n");
2831                 bret = dump_dp_payload_table(mgr, buf);
2832                 if (bret == true) {
2833                         seq_printf(m, "payload table: ");
2834                         for (i = 0; i < 63; i++)
2835                                 seq_printf(m, "%02x ", buf[i]);
2836                         seq_printf(m, "\n");
2837                 }
2838
2839         }
2840
2841         mutex_unlock(&mgr->lock);
2842
2843 }
2844 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2845
2846 static void drm_dp_tx_work(struct work_struct *work)
2847 {
2848         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2849
2850         mutex_lock(&mgr->qlock);
2851         if (mgr->tx_down_in_progress)
2852                 process_single_down_tx_qlock(mgr);
2853         mutex_unlock(&mgr->qlock);
2854 }
2855
2856 static void drm_dp_free_mst_port(struct kref *kref)
2857 {
2858         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2859         kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2860         kfree(port);
2861 }
2862
2863 static void drm_dp_destroy_connector_work(struct work_struct *work)
2864 {
2865         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2866         struct drm_dp_mst_port *port;
2867         bool send_hotplug = false;
2868         /*
2869          * Not a regular list traverse as we have to drop the destroy
2870          * connector lock before destroying the connector, to avoid AB->BA
2871          * ordering between this lock and the config mutex.
2872          */
2873         for (;;) {
2874                 mutex_lock(&mgr->destroy_connector_lock);
2875                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2876                 if (!port) {
2877                         mutex_unlock(&mgr->destroy_connector_lock);
2878                         break;
2879                 }
2880                 list_del(&port->next);
2881                 mutex_unlock(&mgr->destroy_connector_lock);
2882
2883                 kref_init(&port->kref);
2884                 INIT_LIST_HEAD(&port->next);
2885
2886                 mgr->cbs->destroy_connector(mgr, port->connector);
2887
2888                 drm_dp_port_teardown_pdt(port, port->pdt);
2889
2890                 if (!port->input && port->vcpi.vcpi > 0) {
2891                         if (mgr->mst_state) {
2892                                 drm_dp_mst_reset_vcpi_slots(mgr, port);
2893                                 drm_dp_update_payload_part1(mgr);
2894                                 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2895                         }
2896                 }
2897
2898                 kref_put(&port->kref, drm_dp_free_mst_port);
2899                 send_hotplug = true;
2900         }
2901         if (send_hotplug)
2902                 (*mgr->cbs->hotplug)(mgr);
2903 }
2904
2905 /**
2906  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2907  * @mgr: manager struct to initialise
2908  * @dev: device providing this structure - for i2c addition.
2909  * @aux: DP helper aux channel to talk to this device
2910  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2911  * @max_payloads: maximum number of payloads this GPU can source
2912  * @conn_base_id: the connector object ID the MST device is connected to.
2913  *
2914  * Return 0 for success, or negative error code on failure
2915  */
2916 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2917                                  struct device *dev, struct drm_dp_aux *aux,
2918                                  int max_dpcd_transaction_bytes,
2919                                  int max_payloads, int conn_base_id)
2920 {
2921         mutex_init(&mgr->lock);
2922         mutex_init(&mgr->qlock);
2923         mutex_init(&mgr->payload_lock);
2924         mutex_init(&mgr->destroy_connector_lock);
2925         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2926         INIT_LIST_HEAD(&mgr->destroy_connector_list);
2927         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2928         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2929         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2930         init_waitqueue_head(&mgr->tx_waitq);
2931         mgr->dev = dev;
2932         mgr->aux = aux;
2933         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2934         mgr->max_payloads = max_payloads;
2935         mgr->conn_base_id = conn_base_id;
2936         if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
2937             max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
2938                 return -EINVAL;
2939         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2940         if (!mgr->payloads)
2941                 return -ENOMEM;
2942         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2943         if (!mgr->proposed_vcpis)
2944                 return -ENOMEM;
2945         set_bit(0, &mgr->payload_mask);
2946         if (test_calc_pbn_mode() < 0)
2947                 DRM_ERROR("MST PBN self-test failed\n");
2948
2949         return 0;
2950 }
2951 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2952
2953 /**
2954  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2955  * @mgr: manager to destroy
2956  */
2957 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2958 {
2959         flush_work(&mgr->work);
2960         flush_work(&mgr->destroy_connector_work);
2961         mutex_lock(&mgr->payload_lock);
2962         kfree(mgr->payloads);
2963         mgr->payloads = NULL;
2964         kfree(mgr->proposed_vcpis);
2965         mgr->proposed_vcpis = NULL;
2966         mutex_unlock(&mgr->payload_lock);
2967         mgr->dev = NULL;
2968         mgr->aux = NULL;
2969 }
2970 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2971
2972 /* I2C device */
2973 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2974                                int num)
2975 {
2976         struct drm_dp_aux *aux = adapter->algo_data;
2977         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2978         struct drm_dp_mst_branch *mstb;
2979         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2980         unsigned int i;
2981         bool reading = false;
2982         struct drm_dp_sideband_msg_req_body msg;
2983         struct drm_dp_sideband_msg_tx *txmsg = NULL;
2984         int ret;
2985
2986         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2987         if (!mstb)
2988                 return -EREMOTEIO;
2989
2990         /* construct i2c msg */
2991         /* see if last msg is a read */
2992         if (msgs[num - 1].flags & I2C_M_RD)
2993                 reading = true;
2994
2995         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2996                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2997                 ret = -EIO;
2998                 goto out;
2999         }
3000
3001         memset(&msg, 0, sizeof(msg));
3002         msg.req_type = DP_REMOTE_I2C_READ;
3003         msg.u.i2c_read.num_transactions = num - 1;
3004         msg.u.i2c_read.port_number = port->port_num;
3005         for (i = 0; i < num - 1; i++) {
3006                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3007                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3008                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3009         }
3010         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3011         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3012
3013         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3014         if (!txmsg) {
3015                 ret = -ENOMEM;
3016                 goto out;
3017         }
3018
3019         txmsg->dst = mstb;
3020         drm_dp_encode_sideband_req(&msg, txmsg);
3021
3022         drm_dp_queue_down_tx(mgr, txmsg);
3023
3024         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3025         if (ret > 0) {
3026
3027                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3028                         ret = -EREMOTEIO;
3029                         goto out;
3030                 }
3031                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3032                         ret = -EIO;
3033                         goto out;
3034                 }
3035                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3036                 ret = num;
3037         }
3038 out:
3039         kfree(txmsg);
3040         drm_dp_put_mst_branch_device(mstb);
3041         return ret;
3042 }
3043
3044 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3045 {
3046         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3047                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3048                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3049                I2C_FUNC_10BIT_ADDR;
3050 }
3051
3052 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3053         .functionality = drm_dp_mst_i2c_functionality,
3054         .master_xfer = drm_dp_mst_i2c_xfer,
3055 };
3056
3057 /**
3058  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3059  * @aux: DisplayPort AUX channel
3060  *
3061  * Returns 0 on success or a negative error code on failure.
3062  */
3063 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3064 {
3065         aux->ddc.algo = &drm_dp_mst_i2c_algo;
3066         aux->ddc.algo_data = aux;
3067         aux->ddc.retries = 3;
3068
3069         aux->ddc.class = I2C_CLASS_DDC;
3070         aux->ddc.owner = THIS_MODULE;
3071         aux->ddc.dev.parent = aux->dev;
3072         aux->ddc.dev.of_node = aux->dev->of_node;
3073
3074         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3075                 sizeof(aux->ddc.name));
3076
3077         return i2c_add_adapter(&aux->ddc);
3078 }
3079
3080 /**
3081  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3082  * @aux: DisplayPort AUX channel
3083  */
3084 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3085 {
3086         i2c_del_adapter(&aux->ddc);
3087 }