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