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