include/linux/qed/qed_chain.h

   1 /* QLogic qed NIC Driver
   2  * Copyright (c) 2015 QLogic Corporation
   3  *
   4  * This software is available under the terms of the GNU General Public License
   5  * (GPL) Version 2, available from the file COPYING in the main directory of
   6  * this source tree.
   7  */
   8
   9 #ifndef _QED_CHAIN_H
  10 #define _QED_CHAIN_H
  11
  12 #include <linux/types.h>
  13 #include <asm/byteorder.h>
  14 #include <linux/kernel.h>
  15 #include <linux/list.h>
  16 #include <linux/slab.h>
  17 #include <linux/qed/common_hsi.h>
  18
  19 /* dma_addr_t manip */
  20 #define DMA_LO_LE(x)            cpu_to_le32(lower_32_bits(x))
  21 #define DMA_HI_LE(x)            cpu_to_le32(upper_32_bits(x))
  22 #define DMA_REGPAIR_LE(x, val)  do { \
  23                                         (x).hi = DMA_HI_LE((val)); \
  24                                         (x).lo = DMA_LO_LE((val)); \
  25                                 } while (0)
  26
  27 #define HILO_GEN(hi, lo, type)  ((((type)(hi)) << 32) + (lo))
  28 #define HILO_DMA(hi, lo)        HILO_GEN(hi, lo, dma_addr_t)
  29 #define HILO_64(hi, lo) HILO_GEN((le32_to_cpu(hi)), (le32_to_cpu(lo)), u64)
  30 #define HILO_DMA_REGPAIR(regpair)       (HILO_DMA(regpair.hi, regpair.lo))
  31 #define HILO_64_REGPAIR(regpair)        (HILO_64(regpair.hi, regpair.lo))
  32
  33 enum qed_chain_mode {
  34         /* Each Page contains a next pointer at its end */
  35         QED_CHAIN_MODE_NEXT_PTR,
  36
  37         /* Chain is a single page (next ptr) is unrequired */
  38         QED_CHAIN_MODE_SINGLE,
  39
  40         /* Page pointers are located in a side list */
  41         QED_CHAIN_MODE_PBL,
  42 };
  43
  44 enum qed_chain_use_mode {
  45         QED_CHAIN_USE_TO_PRODUCE,               /* Chain starts empty */
  46         QED_CHAIN_USE_TO_CONSUME,               /* Chain starts full */
  47         QED_CHAIN_USE_TO_CONSUME_PRODUCE,       /* Chain starts empty */
  48 };
  49
  50 struct qed_chain_next {
  51         struct regpair  next_phys;
  52         void            *next_virt;
  53 };
  54
  55 struct qed_chain_pbl {
  56         dma_addr_t      p_phys_table;
  57         void            *p_virt_table;
  58         u16             prod_page_idx;
  59         u16             cons_page_idx;
  60 };
  61
  62 struct qed_chain {
  63         void                    *p_virt_addr;
  64         dma_addr_t              p_phys_addr;
  65         void                    *p_prod_elem;
  66         void                    *p_cons_elem;
  67         u16                     page_cnt;
  68         enum qed_chain_mode     mode;
  69         enum qed_chain_use_mode intended_use; /* used to produce/consume */
  70         u16                     capacity; /*< number of _usable_ elements */
  71         u16                     size; /* number of elements */
  72         u16                     prod_idx;
  73         u16                     cons_idx;
  74         u16                     elem_per_page;
  75         u16                     elem_per_page_mask;
  76         u16                     elem_unusable;
  77         u16                     usable_per_page;
  78         u16                     elem_size;
  79         u16                     next_page_mask;
  80         struct qed_chain_pbl    pbl;
  81 };
  82
  83 #define QED_CHAIN_PBL_ENTRY_SIZE        (8)
  84 #define QED_CHAIN_PAGE_SIZE             (0x1000)
  85 #define ELEMS_PER_PAGE(elem_size)       (QED_CHAIN_PAGE_SIZE / (elem_size))
  86
  87 #define UNUSABLE_ELEMS_PER_PAGE(elem_size, mode)     \
  88         ((mode == QED_CHAIN_MODE_NEXT_PTR) ?         \
  89          (1 + ((sizeof(struct qed_chain_next) - 1) / \
  90                (elem_size))) : 0)
  91
  92 #define USABLE_ELEMS_PER_PAGE(elem_size, mode) \
  93         ((u32)(ELEMS_PER_PAGE(elem_size) -     \
  94                UNUSABLE_ELEMS_PER_PAGE(elem_size, mode)))
  95
  96 #define QED_CHAIN_PAGE_CNT(elem_cnt, elem_size, mode) \
  97         DIV_ROUND_UP(elem_cnt, USABLE_ELEMS_PER_PAGE(elem_size, mode))
  98
  99 /* Accessors */
 100 static inline u16 qed_chain_get_prod_idx(struct qed_chain *p_chain)
 101 {
 102         return p_chain->prod_idx;
 103 }
 104
 105 static inline u16 qed_chain_get_cons_idx(struct qed_chain *p_chain)
 106 {
 107         return p_chain->cons_idx;
 108 }
 109
 110 static inline u16 qed_chain_get_elem_left(struct qed_chain *p_chain)
 111 {
 112         u16 used;
 113
 114         /* we don't need to trancate upon assignmet, as we assign u32->u16 */
 115         used = ((u32)0x10000u + (u32)(p_chain->prod_idx)) -
 116                 (u32)p_chain->cons_idx;
 117         if (p_chain->mode == QED_CHAIN_MODE_NEXT_PTR)
 118                 used -= p_chain->prod_idx / p_chain->elem_per_page -
 119                         p_chain->cons_idx / p_chain->elem_per_page;
 120
 121         return p_chain->capacity - used;
 122 }
 123
 124 static inline u8 qed_chain_is_full(struct qed_chain *p_chain)
 125 {
 126         return qed_chain_get_elem_left(p_chain) == p_chain->capacity;
 127 }
 128
 129 static inline u8 qed_chain_is_empty(struct qed_chain *p_chain)
 130 {
 131         return qed_chain_get_elem_left(p_chain) == 0;
 132 }
 133
 134 static inline u16 qed_chain_get_elem_per_page(
 135         struct qed_chain *p_chain)
 136 {
 137         return p_chain->elem_per_page;
 138 }
 139
 140 static inline u16 qed_chain_get_usable_per_page(
 141         struct qed_chain *p_chain)
 142 {
 143         return p_chain->usable_per_page;
 144 }
 145
 146 static inline u16 qed_chain_get_unusable_per_page(
 147         struct qed_chain *p_chain)
 148 {
 149         return p_chain->elem_unusable;
 150 }
 151
 152 static inline u16 qed_chain_get_size(struct qed_chain *p_chain)
 153 {
 154         return p_chain->size;
 155 }
 156
 157 static inline dma_addr_t
 158 qed_chain_get_pbl_phys(struct qed_chain *p_chain)
 159 {
 160         return p_chain->pbl.p_phys_table;
 161 }
 162
 163 /**
 164  * @brief qed_chain_advance_page -
 165  *
 166  * Advance the next element accros pages for a linked chain
 167  *
 168  * @param p_chain
 169  * @param p_next_elem
 170  * @param idx_to_inc
 171  * @param page_to_inc
 172  */
 173 static inline void
 174 qed_chain_advance_page(struct qed_chain *p_chain,
 175                        void **p_next_elem,
 176                        u16 *idx_to_inc,
 177                        u16 *page_to_inc)
 178
 179 {
 180         switch (p_chain->mode) {
 181         case QED_CHAIN_MODE_NEXT_PTR:
 182         {
 183                 struct qed_chain_next *p_next = *p_next_elem;
 184                 *p_next_elem = p_next->next_virt;
 185                 *idx_to_inc += p_chain->elem_unusable;
 186                 break;
 187         }
 188         case QED_CHAIN_MODE_SINGLE:
 189                 *p_next_elem = p_chain->p_virt_addr;
 190                 break;
 191
 192         case QED_CHAIN_MODE_PBL:
 193                 /* It is assumed pages are sequential, next element needs
 194                  * to change only when passing going back to first from last.
 195                  */
 196                 if (++(*page_to_inc) == p_chain->page_cnt) {
 197                         *page_to_inc = 0;
 198                         *p_next_elem = p_chain->p_virt_addr;
 199                 }
 200         }
 201 }
 202
 203 #define is_unusable_idx(p, idx) \
 204         (((p)->idx & (p)->elem_per_page_mask) == (p)->usable_per_page)
 205
 206 #define is_unusable_next_idx(p, idx) \
 207         ((((p)->idx + 1) & (p)->elem_per_page_mask) == (p)->usable_per_page)
 208
 209 #define test_ans_skip(p, idx)                           \
 210         do {                                            \
 211                 if (is_unusable_idx(p, idx)) {          \
 212                         (p)->idx += (p)->elem_unusable; \
 213                 }                                       \
 214         } while (0)
 215
 216 /**
 217  * @brief qed_chain_return_multi_produced -
 218  *
 219  * A chain in which the driver "Produces" elements should use this API
 220  * to indicate previous produced elements are now consumed.
 221  *
 222  * @param p_chain
 223  * @param num
 224  */
 225 static inline void
 226 qed_chain_return_multi_produced(struct qed_chain *p_chain,
 227                                 u16 num)
 228 {
 229         p_chain->cons_idx += num;
 230         test_ans_skip(p_chain, cons_idx);
 231 }
 232
 233 /**
 234  * @brief qed_chain_return_produced -
 235  *
 236  * A chain in which the driver "Produces" elements should use this API
 237  * to indicate previous produced elements are now consumed.
 238  *
 239  * @param p_chain
 240  */
 241 static inline void qed_chain_return_produced(struct qed_chain *p_chain)
 242 {
 243         p_chain->cons_idx++;
 244         test_ans_skip(p_chain, cons_idx);
 245 }
 246
 247 /**
 248  * @brief qed_chain_produce -
 249  *
 250  * A chain in which the driver "Produces" elements should use this to get
 251  * a pointer to the next element which can be "Produced". It's driver
 252  * responsibility to validate that the chain has room for new element.
 253  *
 254  * @param p_chain
 255  *
 256  * @return void*, a pointer to next element
 257  */
 258 static inline void *qed_chain_produce(struct qed_chain *p_chain)
 259 {
 260         void *ret = NULL;
 261
 262         if ((p_chain->prod_idx & p_chain->elem_per_page_mask) ==
 263             p_chain->next_page_mask) {
 264                 qed_chain_advance_page(p_chain, &p_chain->p_prod_elem,
 265                                        &p_chain->prod_idx,
 266                                        &p_chain->pbl.prod_page_idx);
 267         }
 268
 269         ret = p_chain->p_prod_elem;
 270         p_chain->prod_idx++;
 271         p_chain->p_prod_elem = (void *)(((u8 *)p_chain->p_prod_elem) +
 272                                         p_chain->elem_size);
 273
 274         return ret;
 275 }
 276
 277 /**
 278  * @brief qed_chain_get_capacity -
 279  *
 280  * Get the maximum number of BDs in chain
 281  *
 282  * @param p_chain
 283  * @param num
 284  *
 285  * @return u16, number of unusable BDs
 286  */
 287 static inline u16 qed_chain_get_capacity(struct qed_chain *p_chain)
 288 {
 289         return p_chain->capacity;
 290 }
 291
 292 /**
 293  * @brief qed_chain_recycle_consumed -
 294  *
 295  * Returns an element which was previously consumed;
 296  * Increments producers so they could be written to FW.
 297  *
 298  * @param p_chain
 299  */
 300 static inline void
 301 qed_chain_recycle_consumed(struct qed_chain *p_chain)
 302 {
 303         test_ans_skip(p_chain, prod_idx);
 304         p_chain->prod_idx++;
 305 }
 306
 307 /**
 308  * @brief qed_chain_consume -
 309  *
 310  * A Chain in which the driver utilizes data written by a different source
 311  * (i.e., FW) should use this to access passed buffers.
 312  *
 313  * @param p_chain
 314  *
 315  * @return void*, a pointer to the next buffer written
 316  */
 317 static inline void *qed_chain_consume(struct qed_chain *p_chain)
 318 {
 319         void *ret = NULL;
 320
 321         if ((p_chain->cons_idx & p_chain->elem_per_page_mask) ==
 322             p_chain->next_page_mask) {
 323                 qed_chain_advance_page(p_chain, &p_chain->p_cons_elem,
 324                                        &p_chain->cons_idx,
 325                                        &p_chain->pbl.cons_page_idx);
 326         }
 327
 328         ret = p_chain->p_cons_elem;
 329         p_chain->cons_idx++;
 330         p_chain->p_cons_elem = (void *)(((u8 *)p_chain->p_cons_elem) +
 331                                         p_chain->elem_size);
 332
 333         return ret;
 334 }
 335
 336 /**
 337  * @brief qed_chain_reset - Resets the chain to its start state
 338  *
 339  * @param p_chain pointer to a previously allocted chain
 340  */
 341 static inline void qed_chain_reset(struct qed_chain *p_chain)
 342 {
 343         int i;
 344
 345         p_chain->prod_idx       = 0;
 346         p_chain->cons_idx       = 0;
 347         p_chain->p_cons_elem    = p_chain->p_virt_addr;
 348         p_chain->p_prod_elem    = p_chain->p_virt_addr;
 349
 350         if (p_chain->mode == QED_CHAIN_MODE_PBL) {
 351                 p_chain->pbl.prod_page_idx      = p_chain->page_cnt - 1;
 352                 p_chain->pbl.cons_page_idx      = p_chain->page_cnt - 1;
 353         }
 354
 355         switch (p_chain->intended_use) {
 356         case QED_CHAIN_USE_TO_CONSUME_PRODUCE:
 357         case QED_CHAIN_USE_TO_PRODUCE:
 358                 /* Do nothing */
 359                 break;
 360
 361         case QED_CHAIN_USE_TO_CONSUME:
 362                 /* produce empty elements */
 363                 for (i = 0; i < p_chain->capacity; i++)
 364                         qed_chain_recycle_consumed(p_chain);
 365                 break;
 366         }
 367 }
 368
 369 /**
 370  * @brief qed_chain_init - Initalizes a basic chain struct
 371  *
 372  * @param p_chain
 373  * @param p_virt_addr
 374  * @param p_phys_addr   physical address of allocated buffer's beginning
 375  * @param page_cnt      number of pages in the allocated buffer
 376  * @param elem_size     size of each element in the chain
 377  * @param intended_use
 378  * @param mode
 379  */
 380 static inline void qed_chain_init(struct qed_chain *p_chain,
 381                                   void *p_virt_addr,
 382                                   dma_addr_t p_phys_addr,
 383                                   u16 page_cnt,
 384                                   u8 elem_size,
 385                                   enum qed_chain_use_mode intended_use,
 386                                   enum qed_chain_mode mode)
 387 {
 388         /* chain fixed parameters */
 389         p_chain->p_virt_addr    = p_virt_addr;
 390         p_chain->p_phys_addr    = p_phys_addr;
 391         p_chain->elem_size      = elem_size;
 392         p_chain->page_cnt       = page_cnt;
 393         p_chain->mode           = mode;
 394
 395         p_chain->intended_use           = intended_use;
 396         p_chain->elem_per_page          = ELEMS_PER_PAGE(elem_size);
 397         p_chain->usable_per_page =
 398                 USABLE_ELEMS_PER_PAGE(elem_size, mode);
 399         p_chain->capacity               = p_chain->usable_per_page * page_cnt;
 400         p_chain->size                   = p_chain->elem_per_page * page_cnt;
 401         p_chain->elem_per_page_mask     = p_chain->elem_per_page - 1;
 402
 403         p_chain->elem_unusable = UNUSABLE_ELEMS_PER_PAGE(elem_size, mode);
 404
 405         p_chain->next_page_mask = (p_chain->usable_per_page &
 406                                    p_chain->elem_per_page_mask);
 407
 408         if (mode == QED_CHAIN_MODE_NEXT_PTR) {
 409                 struct qed_chain_next   *p_next;
 410                 u16                     i;
 411
 412                 for (i = 0; i < page_cnt - 1; i++) {
 413                         /* Increment mem_phy to the next page. */
 414                         p_phys_addr += QED_CHAIN_PAGE_SIZE;
 415
 416                         /* Initialize the physical address of the next page. */
 417                         p_next = (struct qed_chain_next *)((u8 *)p_virt_addr +
 418                                                            elem_size *
 419                                                            p_chain->
 420                                                            usable_per_page);
 421
 422                         p_next->next_phys.lo    = DMA_LO_LE(p_phys_addr);
 423                         p_next->next_phys.hi    = DMA_HI_LE(p_phys_addr);
 424
 425                         /* Initialize the virtual address of the next page. */
 426                         p_next->next_virt = (void *)((u8 *)p_virt_addr +
 427                                                      QED_CHAIN_PAGE_SIZE);
 428
 429                         /* Move to the next page. */
 430                         p_virt_addr = p_next->next_virt;
 431                 }
 432
 433                 /* Last page's next should point to beginning of the chain */
 434                 p_next = (struct qed_chain_next *)((u8 *)p_virt_addr +
 435                                                    elem_size *
 436                                                    p_chain->usable_per_page);
 437
 438                 p_next->next_phys.lo    = DMA_LO_LE(p_chain->p_phys_addr);
 439                 p_next->next_phys.hi    = DMA_HI_LE(p_chain->p_phys_addr);
 440                 p_next->next_virt       = p_chain->p_virt_addr;
 441         }
 442         qed_chain_reset(p_chain);
 443 }
 444
 445 /**
 446  * @brief qed_chain_pbl_init - Initalizes a basic pbl chain
 447  *        struct
 448  * @param p_chain
 449  * @param p_virt_addr   virtual address of allocated buffer's beginning
 450  * @param p_phys_addr   physical address of allocated buffer's beginning
 451  * @param page_cnt      number of pages in the allocated buffer
 452  * @param elem_size     size of each element in the chain
 453  * @param use_mode
 454  * @param p_phys_pbl    pointer to a pre-allocated side table
 455  *                      which will hold physical page addresses.
 456  * @param p_virt_pbl    pointer to a pre allocated side table
 457  *                      which will hold virtual page addresses.
 458  */
 459 static inline void
 460 qed_chain_pbl_init(struct qed_chain *p_chain,
 461                    void *p_virt_addr,
 462                    dma_addr_t p_phys_addr,
 463                    u16 page_cnt,
 464                    u8 elem_size,
 465                    enum qed_chain_use_mode use_mode,
 466                    dma_addr_t p_phys_pbl,
 467                    dma_addr_t *p_virt_pbl)
 468 {
 469         dma_addr_t *p_pbl_dma = p_virt_pbl;
 470         int i;
 471
 472         qed_chain_init(p_chain, p_virt_addr, p_phys_addr, page_cnt,
 473                        elem_size, use_mode, QED_CHAIN_MODE_PBL);
 474
 475         p_chain->pbl.p_phys_table = p_phys_pbl;
 476         p_chain->pbl.p_virt_table = p_virt_pbl;
 477
 478         /* Fill the PBL with physical addresses*/
 479         for (i = 0; i < page_cnt; i++) {
 480                 *p_pbl_dma = p_phys_addr;
 481                 p_phys_addr += QED_CHAIN_PAGE_SIZE;
 482                 p_pbl_dma++;
 483         }
 484 }
 485
 486 /**
 487  * @brief qed_chain_set_prod - sets the prod to the given
 488  *        value
 489  *
 490  * @param prod_idx
 491  * @param p_prod_elem
 492  */
 493 static inline void qed_chain_set_prod(struct qed_chain *p_chain,
 494                                       u16 prod_idx,
 495                                       void *p_prod_elem)
 496 {
 497         p_chain->prod_idx       = prod_idx;
 498         p_chain->p_prod_elem    = p_prod_elem;
 499 }
 500
 501 /**
 502  * @brief qed_chain_get_elem -
 503  *
 504  * get a pointer to an element represented by absolute idx
 505  *
 506  * @param p_chain
 507  * @assumption p_chain->size is a power of 2
 508  *
 509  * @return void*, a pointer to next element
 510  */
 511 static inline void *qed_chain_sge_get_elem(struct qed_chain *p_chain,
 512                                            u16 idx)
 513 {
 514         void *ret = NULL;
 515
 516         if (idx >= p_chain->size)
 517                 return NULL;
 518
 519         ret = (u8 *)p_chain->p_virt_addr + p_chain->elem_size * idx;
 520
 521         return ret;
 522 }
 523
 524 /**
 525  * @brief qed_chain_sge_inc_cons_prod
 526  *
 527  * for sge chains, producer isn't increased serially, the ring
 528  * is expected to be full at all times. Once elements are
 529  * consumed, they are immediately produced.
 530  *
 531  * @param p_chain
 532  * @param cnt
 533  *
 534  * @return inline void
 535  */
 536 static inline void
 537 qed_chain_sge_inc_cons_prod(struct qed_chain *p_chain,
 538                             u16 cnt)
 539 {
 540         p_chain->prod_idx += cnt;
 541         p_chain->cons_idx += cnt;
 542 }
 543
 544 #endif