linux/include/linux/qed/qed_chain.h
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   1/* QLogic qed NIC Driver
   2 * Copyright (c) 2015-2017  QLogic Corporation
   3 *
   4 * This software is available to you under a choice of one of two
   5 * licenses.  You may choose to be licensed under the terms of the GNU
   6 * General Public License (GPL) Version 2, available from the file
   7 * COPYING in the main directory of this source tree, or the
   8 * OpenIB.org BSD license below:
   9 *
  10 *     Redistribution and use in source and binary forms, with or
  11 *     without modification, are permitted provided that the following
  12 *     conditions are met:
  13 *
  14 *      - Redistributions of source code must retain the above
  15 *        copyright notice, this list of conditions and the following
  16 *        disclaimer.
  17 *
  18 *      - Redistributions in binary form must reproduce the above
  19 *        copyright notice, this list of conditions and the following
  20 *        disclaimer in the documentation and /or other materials
  21 *        provided with the distribution.
  22 *
  23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30 * SOFTWARE.
  31 */
  32
  33#ifndef _QED_CHAIN_H
  34#define _QED_CHAIN_H
  35
  36#include <linux/types.h>
  37#include <asm/byteorder.h>
  38#include <linux/kernel.h>
  39#include <linux/list.h>
  40#include <linux/slab.h>
  41#include <linux/qed/common_hsi.h>
  42
  43enum qed_chain_mode {
  44        /* Each Page contains a next pointer at its end */
  45        QED_CHAIN_MODE_NEXT_PTR,
  46
  47        /* Chain is a single page (next ptr) is unrequired */
  48        QED_CHAIN_MODE_SINGLE,
  49
  50        /* Page pointers are located in a side list */
  51        QED_CHAIN_MODE_PBL,
  52};
  53
  54enum qed_chain_use_mode {
  55        QED_CHAIN_USE_TO_PRODUCE,               /* Chain starts empty */
  56        QED_CHAIN_USE_TO_CONSUME,               /* Chain starts full */
  57        QED_CHAIN_USE_TO_CONSUME_PRODUCE,       /* Chain starts empty */
  58};
  59
  60enum qed_chain_cnt_type {
  61        /* The chain's size/prod/cons are kept in 16-bit variables */
  62        QED_CHAIN_CNT_TYPE_U16,
  63
  64        /* The chain's size/prod/cons are kept in 32-bit variables  */
  65        QED_CHAIN_CNT_TYPE_U32,
  66};
  67
  68struct qed_chain_next {
  69        struct regpair  next_phys;
  70        void            *next_virt;
  71};
  72
  73struct qed_chain_pbl_u16 {
  74        u16 prod_page_idx;
  75        u16 cons_page_idx;
  76};
  77
  78struct qed_chain_pbl_u32 {
  79        u32 prod_page_idx;
  80        u32 cons_page_idx;
  81};
  82
  83struct qed_chain_ext_pbl {
  84        dma_addr_t p_pbl_phys;
  85        void *p_pbl_virt;
  86};
  87
  88struct qed_chain_u16 {
  89        /* Cyclic index of next element to produce/consme */
  90        u16 prod_idx;
  91        u16 cons_idx;
  92};
  93
  94struct qed_chain_u32 {
  95        /* Cyclic index of next element to produce/consme */
  96        u32 prod_idx;
  97        u32 cons_idx;
  98};
  99
 100struct qed_chain {
 101        /* fastpath portion of the chain - required for commands such
 102         * as produce / consume.
 103         */
 104        /* Point to next element to produce/consume */
 105        void *p_prod_elem;
 106        void *p_cons_elem;
 107
 108        /* Fastpath portions of the PBL [if exists] */
 109        struct {
 110                /* Table for keeping the virtual addresses of the chain pages,
 111                 * respectively to the physical addresses in the pbl table.
 112                 */
 113                void **pp_virt_addr_tbl;
 114
 115                union {
 116                        struct qed_chain_pbl_u16 u16;
 117                        struct qed_chain_pbl_u32 u32;
 118                } c;
 119        } pbl;
 120
 121        union {
 122                struct qed_chain_u16 chain16;
 123                struct qed_chain_u32 chain32;
 124        } u;
 125
 126        /* Capacity counts only usable elements */
 127        u32 capacity;
 128        u32 page_cnt;
 129
 130        enum qed_chain_mode mode;
 131
 132        /* Elements information for fast calculations */
 133        u16 elem_per_page;
 134        u16 elem_per_page_mask;
 135        u16 elem_size;
 136        u16 next_page_mask;
 137        u16 usable_per_page;
 138        u8 elem_unusable;
 139
 140        u8 cnt_type;
 141
 142        /* Slowpath of the chain - required for initialization and destruction,
 143         * but isn't involved in regular functionality.
 144         */
 145
 146        /* Base address of a pre-allocated buffer for pbl */
 147        struct {
 148                dma_addr_t p_phys_table;
 149                void *p_virt_table;
 150        } pbl_sp;
 151
 152        /* Address of first page of the chain - the address is required
 153         * for fastpath operation [consume/produce] but only for the the SINGLE
 154         * flavour which isn't considered fastpath [== SPQ].
 155         */
 156        void *p_virt_addr;
 157        dma_addr_t p_phys_addr;
 158
 159        /* Total number of elements [for entire chain] */
 160        u32 size;
 161
 162        u8 intended_use;
 163
 164        bool b_external_pbl;
 165};
 166
 167#define QED_CHAIN_PBL_ENTRY_SIZE        (8)
 168#define QED_CHAIN_PAGE_SIZE             (0x1000)
 169#define ELEMS_PER_PAGE(elem_size)       (QED_CHAIN_PAGE_SIZE / (elem_size))
 170
 171#define UNUSABLE_ELEMS_PER_PAGE(elem_size, mode)         \
 172        (((mode) == QED_CHAIN_MODE_NEXT_PTR) ?           \
 173         (u8)(1 + ((sizeof(struct qed_chain_next) - 1) / \
 174                   (elem_size))) : 0)
 175
 176#define USABLE_ELEMS_PER_PAGE(elem_size, mode) \
 177        ((u32)(ELEMS_PER_PAGE(elem_size) -     \
 178               UNUSABLE_ELEMS_PER_PAGE(elem_size, mode)))
 179
 180#define QED_CHAIN_PAGE_CNT(elem_cnt, elem_size, mode) \
 181        DIV_ROUND_UP(elem_cnt, USABLE_ELEMS_PER_PAGE(elem_size, mode))
 182
 183#define is_chain_u16(p) ((p)->cnt_type == QED_CHAIN_CNT_TYPE_U16)
 184#define is_chain_u32(p) ((p)->cnt_type == QED_CHAIN_CNT_TYPE_U32)
 185
 186/* Accessors */
 187static inline u16 qed_chain_get_prod_idx(struct qed_chain *p_chain)
 188{
 189        return p_chain->u.chain16.prod_idx;
 190}
 191
 192static inline u16 qed_chain_get_cons_idx(struct qed_chain *p_chain)
 193{
 194        return p_chain->u.chain16.cons_idx;
 195}
 196
 197static inline u32 qed_chain_get_cons_idx_u32(struct qed_chain *p_chain)
 198{
 199        return p_chain->u.chain32.cons_idx;
 200}
 201
 202static inline u16 qed_chain_get_elem_left(struct qed_chain *p_chain)
 203{
 204        u16 used;
 205
 206        used = (u16) (((u32)0x10000 +
 207                       (u32)p_chain->u.chain16.prod_idx) -
 208                      (u32)p_chain->u.chain16.cons_idx);
 209        if (p_chain->mode == QED_CHAIN_MODE_NEXT_PTR)
 210                used -= p_chain->u.chain16.prod_idx / p_chain->elem_per_page -
 211                    p_chain->u.chain16.cons_idx / p_chain->elem_per_page;
 212
 213        return (u16)(p_chain->capacity - used);
 214}
 215
 216static inline u32 qed_chain_get_elem_left_u32(struct qed_chain *p_chain)
 217{
 218        u32 used;
 219
 220        used = (u32) (((u64)0x100000000ULL +
 221                       (u64)p_chain->u.chain32.prod_idx) -
 222                      (u64)p_chain->u.chain32.cons_idx);
 223        if (p_chain->mode == QED_CHAIN_MODE_NEXT_PTR)
 224                used -= p_chain->u.chain32.prod_idx / p_chain->elem_per_page -
 225                    p_chain->u.chain32.cons_idx / p_chain->elem_per_page;
 226
 227        return p_chain->capacity - used;
 228}
 229
 230static inline u16 qed_chain_get_usable_per_page(struct qed_chain *p_chain)
 231{
 232        return p_chain->usable_per_page;
 233}
 234
 235static inline u8 qed_chain_get_unusable_per_page(struct qed_chain *p_chain)
 236{
 237        return p_chain->elem_unusable;
 238}
 239
 240static inline u32 qed_chain_get_page_cnt(struct qed_chain *p_chain)
 241{
 242        return p_chain->page_cnt;
 243}
 244
 245static inline dma_addr_t qed_chain_get_pbl_phys(struct qed_chain *p_chain)
 246{
 247        return p_chain->pbl_sp.p_phys_table;
 248}
 249
 250/**
 251 * @brief qed_chain_advance_page -
 252 *
 253 * Advance the next element accros pages for a linked chain
 254 *
 255 * @param p_chain
 256 * @param p_next_elem
 257 * @param idx_to_inc
 258 * @param page_to_inc
 259 */
 260static inline void
 261qed_chain_advance_page(struct qed_chain *p_chain,
 262                       void **p_next_elem, void *idx_to_inc, void *page_to_inc)
 263{
 264        struct qed_chain_next *p_next = NULL;
 265        u32 page_index = 0;
 266
 267        switch (p_chain->mode) {
 268        case QED_CHAIN_MODE_NEXT_PTR:
 269                p_next = *p_next_elem;
 270                *p_next_elem = p_next->next_virt;
 271                if (is_chain_u16(p_chain))
 272                        *(u16 *)idx_to_inc += p_chain->elem_unusable;
 273                else
 274                        *(u32 *)idx_to_inc += p_chain->elem_unusable;
 275                break;
 276        case QED_CHAIN_MODE_SINGLE:
 277                *p_next_elem = p_chain->p_virt_addr;
 278                break;
 279
 280        case QED_CHAIN_MODE_PBL:
 281                if (is_chain_u16(p_chain)) {
 282                        if (++(*(u16 *)page_to_inc) == p_chain->page_cnt)
 283                                *(u16 *)page_to_inc = 0;
 284                        page_index = *(u16 *)page_to_inc;
 285                } else {
 286                        if (++(*(u32 *)page_to_inc) == p_chain->page_cnt)
 287                                *(u32 *)page_to_inc = 0;
 288                        page_index = *(u32 *)page_to_inc;
 289                }
 290                *p_next_elem = p_chain->pbl.pp_virt_addr_tbl[page_index];
 291        }
 292}
 293
 294#define is_unusable_idx(p, idx) \
 295        (((p)->u.chain16.idx & (p)->elem_per_page_mask) == (p)->usable_per_page)
 296
 297#define is_unusable_idx_u32(p, idx) \
 298        (((p)->u.chain32.idx & (p)->elem_per_page_mask) == (p)->usable_per_page)
 299#define is_unusable_next_idx(p, idx)                             \
 300        ((((p)->u.chain16.idx + 1) & (p)->elem_per_page_mask) == \
 301         (p)->usable_per_page)
 302
 303#define is_unusable_next_idx_u32(p, idx)                         \
 304        ((((p)->u.chain32.idx + 1) & (p)->elem_per_page_mask) == \
 305         (p)->usable_per_page)
 306
 307#define test_and_skip(p, idx)                                              \
 308        do {                                            \
 309                if (is_chain_u16(p)) {                                     \
 310                        if (is_unusable_idx(p, idx))                       \
 311                                (p)->u.chain16.idx += (p)->elem_unusable;  \
 312                } else {                                                   \
 313                        if (is_unusable_idx_u32(p, idx))                   \
 314                                (p)->u.chain32.idx += (p)->elem_unusable;  \
 315                }                                       \
 316        } while (0)
 317
 318/**
 319 * @brief qed_chain_return_produced -
 320 *
 321 * A chain in which the driver "Produces" elements should use this API
 322 * to indicate previous produced elements are now consumed.
 323 *
 324 * @param p_chain
 325 */
 326static inline void qed_chain_return_produced(struct qed_chain *p_chain)
 327{
 328        if (is_chain_u16(p_chain))
 329                p_chain->u.chain16.cons_idx++;
 330        else
 331                p_chain->u.chain32.cons_idx++;
 332        test_and_skip(p_chain, cons_idx);
 333}
 334
 335/**
 336 * @brief qed_chain_produce -
 337 *
 338 * A chain in which the driver "Produces" elements should use this to get
 339 * a pointer to the next element which can be "Produced". It's driver
 340 * responsibility to validate that the chain has room for new element.
 341 *
 342 * @param p_chain
 343 *
 344 * @return void*, a pointer to next element
 345 */
 346static inline void *qed_chain_produce(struct qed_chain *p_chain)
 347{
 348        void *p_ret = NULL, *p_prod_idx, *p_prod_page_idx;
 349
 350        if (is_chain_u16(p_chain)) {
 351                if ((p_chain->u.chain16.prod_idx &
 352                     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 353                        p_prod_idx = &p_chain->u.chain16.prod_idx;
 354                        p_prod_page_idx = &p_chain->pbl.c.u16.prod_page_idx;
 355                        qed_chain_advance_page(p_chain, &p_chain->p_prod_elem,
 356                                               p_prod_idx, p_prod_page_idx);
 357                }
 358                p_chain->u.chain16.prod_idx++;
 359        } else {
 360                if ((p_chain->u.chain32.prod_idx &
 361                     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 362                        p_prod_idx = &p_chain->u.chain32.prod_idx;
 363                        p_prod_page_idx = &p_chain->pbl.c.u32.prod_page_idx;
 364                        qed_chain_advance_page(p_chain, &p_chain->p_prod_elem,
 365                                               p_prod_idx, p_prod_page_idx);
 366                }
 367                p_chain->u.chain32.prod_idx++;
 368        }
 369
 370        p_ret = p_chain->p_prod_elem;
 371        p_chain->p_prod_elem = (void *)(((u8 *)p_chain->p_prod_elem) +
 372                                        p_chain->elem_size);
 373
 374        return p_ret;
 375}
 376
 377/**
 378 * @brief qed_chain_get_capacity -
 379 *
 380 * Get the maximum number of BDs in chain
 381 *
 382 * @param p_chain
 383 * @param num
 384 *
 385 * @return number of unusable BDs
 386 */
 387static inline u32 qed_chain_get_capacity(struct qed_chain *p_chain)
 388{
 389        return p_chain->capacity;
 390}
 391
 392/**
 393 * @brief qed_chain_recycle_consumed -
 394 *
 395 * Returns an element which was previously consumed;
 396 * Increments producers so they could be written to FW.
 397 *
 398 * @param p_chain
 399 */
 400static inline void qed_chain_recycle_consumed(struct qed_chain *p_chain)
 401{
 402        test_and_skip(p_chain, prod_idx);
 403        if (is_chain_u16(p_chain))
 404                p_chain->u.chain16.prod_idx++;
 405        else
 406                p_chain->u.chain32.prod_idx++;
 407}
 408
 409/**
 410 * @brief qed_chain_consume -
 411 *
 412 * A Chain in which the driver utilizes data written by a different source
 413 * (i.e., FW) should use this to access passed buffers.
 414 *
 415 * @param p_chain
 416 *
 417 * @return void*, a pointer to the next buffer written
 418 */
 419static inline void *qed_chain_consume(struct qed_chain *p_chain)
 420{
 421        void *p_ret = NULL, *p_cons_idx, *p_cons_page_idx;
 422
 423        if (is_chain_u16(p_chain)) {
 424                if ((p_chain->u.chain16.cons_idx &
 425                     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 426                        p_cons_idx = &p_chain->u.chain16.cons_idx;
 427                        p_cons_page_idx = &p_chain->pbl.c.u16.cons_page_idx;
 428                        qed_chain_advance_page(p_chain, &p_chain->p_cons_elem,
 429                                               p_cons_idx, p_cons_page_idx);
 430                }
 431                p_chain->u.chain16.cons_idx++;
 432        } else {
 433                if ((p_chain->u.chain32.cons_idx &
 434                     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 435                        p_cons_idx = &p_chain->u.chain32.cons_idx;
 436                        p_cons_page_idx = &p_chain->pbl.c.u32.cons_page_idx;
 437                        qed_chain_advance_page(p_chain, &p_chain->p_cons_elem,
 438                                               p_cons_idx, p_cons_page_idx);
 439                }
 440                p_chain->u.chain32.cons_idx++;
 441        }
 442
 443        p_ret = p_chain->p_cons_elem;
 444        p_chain->p_cons_elem = (void *)(((u8 *)p_chain->p_cons_elem) +
 445                                        p_chain->elem_size);
 446
 447        return p_ret;
 448}
 449
 450/**
 451 * @brief qed_chain_reset - Resets the chain to its start state
 452 *
 453 * @param p_chain pointer to a previously allocted chain
 454 */
 455static inline void qed_chain_reset(struct qed_chain *p_chain)
 456{
 457        u32 i;
 458
 459        if (is_chain_u16(p_chain)) {
 460                p_chain->u.chain16.prod_idx = 0;
 461                p_chain->u.chain16.cons_idx = 0;
 462        } else {
 463                p_chain->u.chain32.prod_idx = 0;
 464                p_chain->u.chain32.cons_idx = 0;
 465        }
 466        p_chain->p_cons_elem = p_chain->p_virt_addr;
 467        p_chain->p_prod_elem = p_chain->p_virt_addr;
 468
 469        if (p_chain->mode == QED_CHAIN_MODE_PBL) {
 470                /* Use (page_cnt - 1) as a reset value for the prod/cons page's
 471                 * indices, to avoid unnecessary page advancing on the first
 472                 * call to qed_chain_produce/consume. Instead, the indices
 473                 * will be advanced to page_cnt and then will be wrapped to 0.
 474                 */
 475                u32 reset_val = p_chain->page_cnt - 1;
 476
 477                if (is_chain_u16(p_chain)) {
 478                        p_chain->pbl.c.u16.prod_page_idx = (u16)reset_val;
 479                        p_chain->pbl.c.u16.cons_page_idx = (u16)reset_val;
 480                } else {
 481                        p_chain->pbl.c.u32.prod_page_idx = reset_val;
 482                        p_chain->pbl.c.u32.cons_page_idx = reset_val;
 483                }
 484        }
 485
 486        switch (p_chain->intended_use) {
 487        case QED_CHAIN_USE_TO_CONSUME:
 488                /* produce empty elements */
 489                for (i = 0; i < p_chain->capacity; i++)
 490                        qed_chain_recycle_consumed(p_chain);
 491                break;
 492
 493        case QED_CHAIN_USE_TO_CONSUME_PRODUCE:
 494        case QED_CHAIN_USE_TO_PRODUCE:
 495        default:
 496                /* Do nothing */
 497                break;
 498        }
 499}
 500
 501/**
 502 * @brief qed_chain_init - Initalizes a basic chain struct
 503 *
 504 * @param p_chain
 505 * @param p_virt_addr
 506 * @param p_phys_addr   physical address of allocated buffer's beginning
 507 * @param page_cnt      number of pages in the allocated buffer
 508 * @param elem_size     size of each element in the chain
 509 * @param intended_use
 510 * @param mode
 511 */
 512static inline void qed_chain_init_params(struct qed_chain *p_chain,
 513                                         u32 page_cnt,
 514                                         u8 elem_size,
 515                                         enum qed_chain_use_mode intended_use,
 516                                         enum qed_chain_mode mode,
 517                                         enum qed_chain_cnt_type cnt_type)
 518{
 519        /* chain fixed parameters */
 520        p_chain->p_virt_addr = NULL;
 521        p_chain->p_phys_addr = 0;
 522        p_chain->elem_size      = elem_size;
 523        p_chain->intended_use = (u8)intended_use;
 524        p_chain->mode           = mode;
 525        p_chain->cnt_type = (u8)cnt_type;
 526
 527        p_chain->elem_per_page = ELEMS_PER_PAGE(elem_size);
 528        p_chain->usable_per_page = USABLE_ELEMS_PER_PAGE(elem_size, mode);
 529        p_chain->elem_per_page_mask = p_chain->elem_per_page - 1;
 530        p_chain->elem_unusable = UNUSABLE_ELEMS_PER_PAGE(elem_size, mode);
 531        p_chain->next_page_mask = (p_chain->usable_per_page &
 532                                   p_chain->elem_per_page_mask);
 533
 534        p_chain->page_cnt = page_cnt;
 535        p_chain->capacity = p_chain->usable_per_page * page_cnt;
 536        p_chain->size = p_chain->elem_per_page * page_cnt;
 537
 538        p_chain->pbl_sp.p_phys_table = 0;
 539        p_chain->pbl_sp.p_virt_table = NULL;
 540        p_chain->pbl.pp_virt_addr_tbl = NULL;
 541}
 542
 543/**
 544 * @brief qed_chain_init_mem -
 545 *
 546 * Initalizes a basic chain struct with its chain buffers
 547 *
 548 * @param p_chain
 549 * @param p_virt_addr   virtual address of allocated buffer's beginning
 550 * @param p_phys_addr   physical address of allocated buffer's beginning
 551 *
 552 */
 553static inline void qed_chain_init_mem(struct qed_chain *p_chain,
 554                                      void *p_virt_addr, dma_addr_t p_phys_addr)
 555{
 556        p_chain->p_virt_addr = p_virt_addr;
 557        p_chain->p_phys_addr = p_phys_addr;
 558}
 559
 560/**
 561 * @brief qed_chain_init_pbl_mem -
 562 *
 563 * Initalizes a basic chain struct with its pbl buffers
 564 *
 565 * @param p_chain
 566 * @param p_virt_pbl    pointer to a pre allocated side table which will hold
 567 *                      virtual page addresses.
 568 * @param p_phys_pbl    pointer to a pre-allocated side table which will hold
 569 *                      physical page addresses.
 570 * @param pp_virt_addr_tbl
 571 *                      pointer to a pre-allocated side table which will hold
 572 *                      the virtual addresses of the chain pages.
 573 *
 574 */
 575static inline void qed_chain_init_pbl_mem(struct qed_chain *p_chain,
 576                                          void *p_virt_pbl,
 577                                          dma_addr_t p_phys_pbl,
 578                                          void **pp_virt_addr_tbl)
 579{
 580        p_chain->pbl_sp.p_phys_table = p_phys_pbl;
 581        p_chain->pbl_sp.p_virt_table = p_virt_pbl;
 582        p_chain->pbl.pp_virt_addr_tbl = pp_virt_addr_tbl;
 583}
 584
 585/**
 586 * @brief qed_chain_init_next_ptr_elem -
 587 *
 588 * Initalizes a next pointer element
 589 *
 590 * @param p_chain
 591 * @param p_virt_curr   virtual address of a chain page of which the next
 592 *                      pointer element is initialized
 593 * @param p_virt_next   virtual address of the next chain page
 594 * @param p_phys_next   physical address of the next chain page
 595 *
 596 */
 597static inline void
 598qed_chain_init_next_ptr_elem(struct qed_chain *p_chain,
 599                             void *p_virt_curr,
 600                             void *p_virt_next, dma_addr_t p_phys_next)
 601{
 602        struct qed_chain_next *p_next;
 603        u32 size;
 604
 605        size = p_chain->elem_size * p_chain->usable_per_page;
 606        p_next = (struct qed_chain_next *)((u8 *)p_virt_curr + size);
 607
 608        DMA_REGPAIR_LE(p_next->next_phys, p_phys_next);
 609
 610        p_next->next_virt = p_virt_next;
 611}
 612
 613/**
 614 * @brief qed_chain_get_last_elem -
 615 *
 616 * Returns a pointer to the last element of the chain
 617 *
 618 * @param p_chain
 619 *
 620 * @return void*
 621 */
 622static inline void *qed_chain_get_last_elem(struct qed_chain *p_chain)
 623{
 624        struct qed_chain_next *p_next = NULL;
 625        void *p_virt_addr = NULL;
 626        u32 size, last_page_idx;
 627
 628        if (!p_chain->p_virt_addr)
 629                goto out;
 630
 631        switch (p_chain->mode) {
 632        case QED_CHAIN_MODE_NEXT_PTR:
 633                size = p_chain->elem_size * p_chain->usable_per_page;
 634                p_virt_addr = p_chain->p_virt_addr;
 635                p_next = (struct qed_chain_next *)((u8 *)p_virt_addr + size);
 636                while (p_next->next_virt != p_chain->p_virt_addr) {
 637                        p_virt_addr = p_next->next_virt;
 638                        p_next = (struct qed_chain_next *)((u8 *)p_virt_addr +
 639                                                           size);
 640                }
 641                break;
 642        case QED_CHAIN_MODE_SINGLE:
 643                p_virt_addr = p_chain->p_virt_addr;
 644                break;
 645        case QED_CHAIN_MODE_PBL:
 646                last_page_idx = p_chain->page_cnt - 1;
 647                p_virt_addr = p_chain->pbl.pp_virt_addr_tbl[last_page_idx];
 648                break;
 649        }
 650        /* p_virt_addr points at this stage to the last page of the chain */
 651        size = p_chain->elem_size * (p_chain->usable_per_page - 1);
 652        p_virt_addr = (u8 *)p_virt_addr + size;
 653out:
 654        return p_virt_addr;
 655}
 656
 657/**
 658 * @brief qed_chain_set_prod - sets the prod to the given value
 659 *
 660 * @param prod_idx
 661 * @param p_prod_elem
 662 */
 663static inline void qed_chain_set_prod(struct qed_chain *p_chain,
 664                                      u32 prod_idx, void *p_prod_elem)
 665{
 666        if (is_chain_u16(p_chain))
 667                p_chain->u.chain16.prod_idx = (u16) prod_idx;
 668        else
 669                p_chain->u.chain32.prod_idx = prod_idx;
 670        p_chain->p_prod_elem = p_prod_elem;
 671}
 672
 673/**
 674 * @brief qed_chain_pbl_zero_mem - set chain memory to 0
 675 *
 676 * @param p_chain
 677 */
 678static inline void qed_chain_pbl_zero_mem(struct qed_chain *p_chain)
 679{
 680        u32 i, page_cnt;
 681
 682        if (p_chain->mode != QED_CHAIN_MODE_PBL)
 683                return;
 684
 685        page_cnt = qed_chain_get_page_cnt(p_chain);
 686
 687        for (i = 0; i < page_cnt; i++)
 688                memset(p_chain->pbl.pp_virt_addr_tbl[i], 0,
 689                       QED_CHAIN_PAGE_SIZE);
 690}
 691
 692#endif
 693