1/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
2/* QLogic qed NIC Driver
3 * Copyright (c) 2015-2017 QLogic Corporation
4 * Copyright (c) 2019-2020 Marvell International Ltd.
5 */
6
7#ifndef _QED_CHAIN_H
8#define _QED_CHAIN_H
9
10#include <linux/types.h>
11#include <asm/byteorder.h>
12#include <linux/kernel.h>
13#include <linux/list.h>
14#include <linux/sizes.h>
15#include <linux/slab.h>
16#include <linux/qed/common_hsi.h>
17
18enum qed_chain_mode {
19 /* Each Page contains a next pointer at its end */
20 QED_CHAIN_MODE_NEXT_PTR,
21
22 /* Chain is a single page (next ptr) is not required */
23 QED_CHAIN_MODE_SINGLE,
24
25 /* Page pointers are located in a side list */
26 QED_CHAIN_MODE_PBL,
27};
28
29enum qed_chain_use_mode {
30 QED_CHAIN_USE_TO_PRODUCE, /* Chain starts empty */
31 QED_CHAIN_USE_TO_CONSUME, /* Chain starts full */
32 QED_CHAIN_USE_TO_CONSUME_PRODUCE, /* Chain starts empty */
33};
34
35enum qed_chain_cnt_type {
36 /* The chain's size/prod/cons are kept in 16-bit variables */
37 QED_CHAIN_CNT_TYPE_U16,
38
39 /* The chain's size/prod/cons are kept in 32-bit variables */
40 QED_CHAIN_CNT_TYPE_U32,
41};
42
43struct qed_chain_next {
44 struct regpair next_phys;
45 void *next_virt;
46};
47
48struct qed_chain_pbl_u16 {
49 u16 prod_page_idx;
50 u16 cons_page_idx;
51};
52
53struct qed_chain_pbl_u32 {
54 u32 prod_page_idx;
55 u32 cons_page_idx;
56};
57
58struct qed_chain_u16 {
59 /* Cyclic index of next element to produce/consume */
60 u16 prod_idx;
61 u16 cons_idx;
62};
63
64struct qed_chain_u32 {
65 /* Cyclic index of next element to produce/consume */
66 u32 prod_idx;
67 u32 cons_idx;
68};
69
70struct addr_tbl_entry {
71 void *virt_addr;
72 dma_addr_t dma_map;
73};
74
75struct qed_chain {
76 /* Fastpath portion of the chain - required for commands such
77 * as produce / consume.
78 */
79
80 /* Point to next element to produce/consume */
81 void *p_prod_elem;
82 void *p_cons_elem;
83
84 /* Fastpath portions of the PBL [if exists] */
85
86 struct {
87 /* Table for keeping the virtual and physical addresses of the
88 * chain pages, respectively to the physical addresses
89 * in the pbl table.
90 */
91 struct addr_tbl_entry *pp_addr_tbl;
92
93 union {
94 struct qed_chain_pbl_u16 u16;
95 struct qed_chain_pbl_u32 u32;
96 } c;
97 } pbl;
98
99 union {
100 struct qed_chain_u16 chain16;
101 struct qed_chain_u32 chain32;
102 } u;
103
104 /* Capacity counts only usable elements */
105 u32 capacity;
106 u32 page_cnt;
107
108 enum qed_chain_mode mode;
109
110 /* Elements information for fast calculations */
111 u16 elem_per_page;
112 u16 elem_per_page_mask;
113 u16 elem_size;
114 u16 next_page_mask;
115 u16 usable_per_page;
116 u8 elem_unusable;
117
118 enum qed_chain_cnt_type cnt_type;
119
120 /* Slowpath of the chain - required for initialization and destruction,
121 * but isn't involved in regular functionality.
122 */
123
124 u32 page_size;
125
126 /* Base address of a pre-allocated buffer for pbl */
127 struct {
128 __le64 *table_virt;
129 dma_addr_t table_phys;
130 size_t table_size;
131 } pbl_sp;
132
133 /* Address of first page of the chain - the address is required
134 * for fastpath operation [consume/produce] but only for the SINGLE
135 * flavour which isn't considered fastpath [== SPQ].
136 */
137 void *p_virt_addr;
138 dma_addr_t p_phys_addr;
139
140 /* Total number of elements [for entire chain] */
141 u32 size;
142
143 enum qed_chain_use_mode intended_use;
144
145 bool b_external_pbl;
146};
147
148struct qed_chain_init_params {
149 enum qed_chain_mode mode;
150 enum qed_chain_use_mode intended_use;
151 enum qed_chain_cnt_type cnt_type;
152
153 u32 page_size;
154 u32 num_elems;
155 size_t elem_size;
156
157 void *ext_pbl_virt;
158 dma_addr_t ext_pbl_phys;
159};
160
161#define QED_CHAIN_PAGE_SIZE SZ_4K
162
163#define ELEMS_PER_PAGE(elem_size, page_size) \
164 ((page_size) / (elem_size))
165
166#define UNUSABLE_ELEMS_PER_PAGE(elem_size, mode) \
167 (((mode) == QED_CHAIN_MODE_NEXT_PTR) ? \
168 (u8)(1 + ((sizeof(struct qed_chain_next) - 1) / (elem_size))) : \
169 0)
170
171#define USABLE_ELEMS_PER_PAGE(elem_size, page_size, mode) \
172 ((u32)(ELEMS_PER_PAGE((elem_size), (page_size)) - \
173 UNUSABLE_ELEMS_PER_PAGE((elem_size), (mode))))
174
175#define QED_CHAIN_PAGE_CNT(elem_cnt, elem_size, page_size, mode) \
176 DIV_ROUND_UP((elem_cnt), \
177 USABLE_ELEMS_PER_PAGE((elem_size), (page_size), (mode)))
178
179#define is_chain_u16(p) \
180 ((p)->cnt_type == QED_CHAIN_CNT_TYPE_U16)
181#define is_chain_u32(p) \
182 ((p)->cnt_type == QED_CHAIN_CNT_TYPE_U32)
183
184/* Accessors */
185
186static inline u16 qed_chain_get_prod_idx(const struct qed_chain *chain)
187{
188 return chain->u.chain16.prod_idx;
189}
190
191static inline u16 qed_chain_get_cons_idx(const struct qed_chain *chain)
192{
193 return chain->u.chain16.cons_idx;
194}
195
196static inline u32 qed_chain_get_prod_idx_u32(const struct qed_chain *chain)
197{
198 return chain->u.chain32.prod_idx;
199}
200
201static inline u32 qed_chain_get_cons_idx_u32(const struct qed_chain *chain)
202{
203 return chain->u.chain32.cons_idx;
204}
205
206static inline u16 qed_chain_get_elem_used(const struct qed_chain *chain)
207{
208 u32 prod = qed_chain_get_prod_idx(chain);
209 u32 cons = qed_chain_get_cons_idx(chain);
210 u16 elem_per_page = chain->elem_per_page;
211 u16 used;
212
213 if (prod < cons)
214 prod += (u32)U16_MAX + 1;
215
216 used = (u16)(prod - cons);
217 if (chain->mode == QED_CHAIN_MODE_NEXT_PTR)
218 used -= (u16)(prod / elem_per_page - cons / elem_per_page);
219
220 return used;
221}
222
223static inline u16 qed_chain_get_elem_left(const struct qed_chain *chain)
224{
225 return (u16)(chain->capacity - qed_chain_get_elem_used(chain));
226}
227
228static inline u32 qed_chain_get_elem_used_u32(const struct qed_chain *chain)
229{
230 u64 prod = qed_chain_get_prod_idx_u32(chain);
231 u64 cons = qed_chain_get_cons_idx_u32(chain);
232 u16 elem_per_page = chain->elem_per_page;
233 u32 used;
234
235 if (prod < cons)
236 prod += (u64)U32_MAX + 1;
237
238 used = (u32)(prod - cons);
239 if (chain->mode == QED_CHAIN_MODE_NEXT_PTR)
240 used -= (u32)(prod / elem_per_page - cons / elem_per_page);
241
242 return used;
243}
244
245static inline u32 qed_chain_get_elem_left_u32(const struct qed_chain *chain)
246{
247 return chain->capacity - qed_chain_get_elem_used_u32(chain);
248}
249
250static inline u16 qed_chain_get_usable_per_page(const struct qed_chain *chain)
251{
252 return chain->usable_per_page;
253}
254
255static inline u8 qed_chain_get_unusable_per_page(const struct qed_chain *chain)
256{
257 return chain->elem_unusable;
258}
259
260static inline u32 qed_chain_get_page_cnt(const struct qed_chain *chain)
261{
262 return chain->page_cnt;
263}
264
265static inline dma_addr_t qed_chain_get_pbl_phys(const struct qed_chain *chain)
266{
267 return chain->pbl_sp.table_phys;
268}
269
270/**
271 * qed_chain_advance_page(): Advance the next element across pages for a
272 * linked chain.
273 *
274 * @p_chain: P_chain.
275 * @p_next_elem: P_next_elem.
276 * @idx_to_inc: Idx_to_inc.
277 * @page_to_inc: page_to_inc.
278 *
279 * Return: Void.
280 */
281static inline void
282qed_chain_advance_page(struct qed_chain *p_chain,
283 void **p_next_elem, void *idx_to_inc, void *page_to_inc)
284{
285 struct qed_chain_next *p_next = NULL;
286 u32 page_index = 0;
287
288 switch (p_chain->mode) {
289 case QED_CHAIN_MODE_NEXT_PTR:
290 p_next = *p_next_elem;
291 *p_next_elem = p_next->next_virt;
292 if (is_chain_u16(p_chain))
293 *(u16 *)idx_to_inc += p_chain->elem_unusable;
294 else
295 *(u32 *)idx_to_inc += p_chain->elem_unusable;
296 break;
297 case QED_CHAIN_MODE_SINGLE:
298 *p_next_elem = p_chain->p_virt_addr;
299 break;
300
301 case QED_CHAIN_MODE_PBL:
302 if (is_chain_u16(p_chain)) {
303 if (++(*(u16 *)page_to_inc) == p_chain->page_cnt)
304 *(u16 *)page_to_inc = 0;
305 page_index = *(u16 *)page_to_inc;
306 } else {
307 if (++(*(u32 *)page_to_inc) == p_chain->page_cnt)
308 *(u32 *)page_to_inc = 0;
309 page_index = *(u32 *)page_to_inc;
310 }
311 *p_next_elem = p_chain->pbl.pp_addr_tbl[page_index].virt_addr;
312 }
313}
314
315#define is_unusable_idx(p, idx) \
316 (((p)->u.chain16.idx & (p)->elem_per_page_mask) == (p)->usable_per_page)
317
318#define is_unusable_idx_u32(p, idx) \
319 (((p)->u.chain32.idx & (p)->elem_per_page_mask) == (p)->usable_per_page)
320#define is_unusable_next_idx(p, idx) \
321 ((((p)->u.chain16.idx + 1) & (p)->elem_per_page_mask) == \
322 (p)->usable_per_page)
323
324#define is_unusable_next_idx_u32(p, idx) \
325 ((((p)->u.chain32.idx + 1) & (p)->elem_per_page_mask) == \
326 (p)->usable_per_page)
327
328#define test_and_skip(p, idx) \
329 do { \
330 if (is_chain_u16(p)) { \
331 if (is_unusable_idx(p, idx)) \
332 (p)->u.chain16.idx += (p)->elem_unusable; \
333 } else { \
334 if (is_unusable_idx_u32(p, idx)) \
335 (p)->u.chain32.idx += (p)->elem_unusable; \
336 } \
337 } while (0)
338
339/**
340 * qed_chain_return_produced(): A chain in which the driver "Produces"
341 * elements should use this API
342 * to indicate previous produced elements
343 * are now consumed.
344 *
345 * @p_chain: Chain.
346 *
347 * Return: Void.
348 */
349static inline void qed_chain_return_produced(struct qed_chain *p_chain)
350{
351 if (is_chain_u16(p_chain))
352 p_chain->u.chain16.cons_idx++;
353 else
354 p_chain->u.chain32.cons_idx++;
355 test_and_skip(p_chain, cons_idx);
356}
357
358/**
359 * qed_chain_produce(): A chain in which the driver "Produces"
360 * elements should use this to get a pointer to
361 * the next element which can be "Produced". It's driver
362 * responsibility to validate that the chain has room for
363 * new element.
364 *
365 * @p_chain: Chain.
366 *
367 * Return: void*, a pointer to next element.
368 */
369static inline void *qed_chain_produce(struct qed_chain *p_chain)
370{
371 void *p_ret = NULL, *p_prod_idx, *p_prod_page_idx;
372
373 if (is_chain_u16(p_chain)) {
374 if ((p_chain->u.chain16.prod_idx &
375 p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
376 p_prod_idx = &p_chain->u.chain16.prod_idx;
377 p_prod_page_idx = &p_chain->pbl.c.u16.prod_page_idx;
378 qed_chain_advance_page(p_chain, p_next_elem: &p_chain->p_prod_elem,
379 idx_to_inc: p_prod_idx, page_to_inc: p_prod_page_idx);
380 }
381 p_chain->u.chain16.prod_idx++;
382 } else {
383 if ((p_chain->u.chain32.prod_idx &
384 p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
385 p_prod_idx = &p_chain->u.chain32.prod_idx;
386 p_prod_page_idx = &p_chain->pbl.c.u32.prod_page_idx;
387 qed_chain_advance_page(p_chain, p_next_elem: &p_chain->p_prod_elem,
388 idx_to_inc: p_prod_idx, page_to_inc: p_prod_page_idx);
389 }
390 p_chain->u.chain32.prod_idx++;
391 }
392
393 p_ret = p_chain->p_prod_elem;
394 p_chain->p_prod_elem = (void *)(((u8 *)p_chain->p_prod_elem) +
395 p_chain->elem_size);
396
397 return p_ret;
398}
399
400/**
401 * qed_chain_get_capacity(): Get the maximum number of BDs in chain
402 *
403 * @p_chain: Chain.
404 *
405 * Return: number of unusable BDs.
406 */
407static inline u32 qed_chain_get_capacity(struct qed_chain *p_chain)
408{
409 return p_chain->capacity;
410}
411
412/**
413 * qed_chain_recycle_consumed(): Returns an element which was
414 * previously consumed;
415 * Increments producers so they could
416 * be written to FW.
417 *
418 * @p_chain: Chain.
419 *
420 * Return: Void.
421 */
422static inline void qed_chain_recycle_consumed(struct qed_chain *p_chain)
423{
424 test_and_skip(p_chain, prod_idx);
425 if (is_chain_u16(p_chain))
426 p_chain->u.chain16.prod_idx++;
427 else
428 p_chain->u.chain32.prod_idx++;
429}
430
431/**
432 * qed_chain_consume(): A Chain in which the driver utilizes data written
433 * by a different source (i.e., FW) should use this to
434 * access passed buffers.
435 *
436 * @p_chain: Chain.
437 *
438 * Return: void*, a pointer to the next buffer written.
439 */
440static inline void *qed_chain_consume(struct qed_chain *p_chain)
441{
442 void *p_ret = NULL, *p_cons_idx, *p_cons_page_idx;
443
444 if (is_chain_u16(p_chain)) {
445 if ((p_chain->u.chain16.cons_idx &
446 p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
447 p_cons_idx = &p_chain->u.chain16.cons_idx;
448 p_cons_page_idx = &p_chain->pbl.c.u16.cons_page_idx;
449 qed_chain_advance_page(p_chain, p_next_elem: &p_chain->p_cons_elem,
450 idx_to_inc: p_cons_idx, page_to_inc: p_cons_page_idx);
451 }
452 p_chain->u.chain16.cons_idx++;
453 } else {
454 if ((p_chain->u.chain32.cons_idx &
455 p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
456 p_cons_idx = &p_chain->u.chain32.cons_idx;
457 p_cons_page_idx = &p_chain->pbl.c.u32.cons_page_idx;
458 qed_chain_advance_page(p_chain, p_next_elem: &p_chain->p_cons_elem,
459 idx_to_inc: p_cons_idx, page_to_inc: p_cons_page_idx);
460 }
461 p_chain->u.chain32.cons_idx++;
462 }
463
464 p_ret = p_chain->p_cons_elem;
465 p_chain->p_cons_elem = (void *)(((u8 *)p_chain->p_cons_elem) +
466 p_chain->elem_size);
467
468 return p_ret;
469}
470
471/**
472 * qed_chain_reset(): Resets the chain to its start state.
473 *
474 * @p_chain: pointer to a previously allocated chain.
475 *
476 * Return Void.
477 */
478static inline void qed_chain_reset(struct qed_chain *p_chain)
479{
480 u32 i;
481
482 if (is_chain_u16(p_chain)) {
483 p_chain->u.chain16.prod_idx = 0;
484 p_chain->u.chain16.cons_idx = 0;
485 } else {
486 p_chain->u.chain32.prod_idx = 0;
487 p_chain->u.chain32.cons_idx = 0;
488 }
489 p_chain->p_cons_elem = p_chain->p_virt_addr;
490 p_chain->p_prod_elem = p_chain->p_virt_addr;
491
492 if (p_chain->mode == QED_CHAIN_MODE_PBL) {
493 /* Use (page_cnt - 1) as a reset value for the prod/cons page's
494 * indices, to avoid unnecessary page advancing on the first
495 * call to qed_chain_produce/consume. Instead, the indices
496 * will be advanced to page_cnt and then will be wrapped to 0.
497 */
498 u32 reset_val = p_chain->page_cnt - 1;
499
500 if (is_chain_u16(p_chain)) {
501 p_chain->pbl.c.u16.prod_page_idx = (u16)reset_val;
502 p_chain->pbl.c.u16.cons_page_idx = (u16)reset_val;
503 } else {
504 p_chain->pbl.c.u32.prod_page_idx = reset_val;
505 p_chain->pbl.c.u32.cons_page_idx = reset_val;
506 }
507 }
508
509 switch (p_chain->intended_use) {
510 case QED_CHAIN_USE_TO_CONSUME:
511 /* produce empty elements */
512 for (i = 0; i < p_chain->capacity; i++)
513 qed_chain_recycle_consumed(p_chain);
514 break;
515
516 case QED_CHAIN_USE_TO_CONSUME_PRODUCE:
517 case QED_CHAIN_USE_TO_PRODUCE:
518 default:
519 /* Do nothing */
520 break;
521 }
522}
523
524/**
525 * qed_chain_get_last_elem(): Returns a pointer to the last element of the
526 * chain.
527 *
528 * @p_chain: Chain.
529 *
530 * Return: void*.
531 */
532static inline void *qed_chain_get_last_elem(struct qed_chain *p_chain)
533{
534 struct qed_chain_next *p_next = NULL;
535 void *p_virt_addr = NULL;
536 u32 size, last_page_idx;
537
538 if (!p_chain->p_virt_addr)
539 goto out;
540
541 switch (p_chain->mode) {
542 case QED_CHAIN_MODE_NEXT_PTR:
543 size = p_chain->elem_size * p_chain->usable_per_page;
544 p_virt_addr = p_chain->p_virt_addr;
545 p_next = (struct qed_chain_next *)((u8 *)p_virt_addr + size);
546 while (p_next->next_virt != p_chain->p_virt_addr) {
547 p_virt_addr = p_next->next_virt;
548 p_next = (struct qed_chain_next *)((u8 *)p_virt_addr +
549 size);
550 }
551 break;
552 case QED_CHAIN_MODE_SINGLE:
553 p_virt_addr = p_chain->p_virt_addr;
554 break;
555 case QED_CHAIN_MODE_PBL:
556 last_page_idx = p_chain->page_cnt - 1;
557 p_virt_addr = p_chain->pbl.pp_addr_tbl[last_page_idx].virt_addr;
558 break;
559 }
560 /* p_virt_addr points at this stage to the last page of the chain */
561 size = p_chain->elem_size * (p_chain->usable_per_page - 1);
562 p_virt_addr = (u8 *)p_virt_addr + size;
563out:
564 return p_virt_addr;
565}
566
567/**
568 * qed_chain_set_prod(): sets the prod to the given value.
569 *
570 * @p_chain: Chain.
571 * @prod_idx: Prod Idx.
572 * @p_prod_elem: Prod elem.
573 *
574 * Return Void.
575 */
576static inline void qed_chain_set_prod(struct qed_chain *p_chain,
577 u32 prod_idx, void *p_prod_elem)
578{
579 if (p_chain->mode == QED_CHAIN_MODE_PBL) {
580 u32 cur_prod, page_mask, page_cnt, page_diff;
581
582 cur_prod = is_chain_u16(p_chain) ? p_chain->u.chain16.prod_idx :
583 p_chain->u.chain32.prod_idx;
584
585 /* Assume that number of elements in a page is power of 2 */
586 page_mask = ~p_chain->elem_per_page_mask;
587
588 /* Use "cur_prod - 1" and "prod_idx - 1" since producer index
589 * reaches the first element of next page before the page index
590 * is incremented. See qed_chain_produce().
591 * Index wrap around is not a problem because the difference
592 * between current and given producer indices is always
593 * positive and lower than the chain's capacity.
594 */
595 page_diff = (((cur_prod - 1) & page_mask) -
596 ((prod_idx - 1) & page_mask)) /
597 p_chain->elem_per_page;
598
599 page_cnt = qed_chain_get_page_cnt(chain: p_chain);
600 if (is_chain_u16(p_chain))
601 p_chain->pbl.c.u16.prod_page_idx =
602 (p_chain->pbl.c.u16.prod_page_idx -
603 page_diff + page_cnt) % page_cnt;
604 else
605 p_chain->pbl.c.u32.prod_page_idx =
606 (p_chain->pbl.c.u32.prod_page_idx -
607 page_diff + page_cnt) % page_cnt;
608 }
609
610 if (is_chain_u16(p_chain))
611 p_chain->u.chain16.prod_idx = (u16) prod_idx;
612 else
613 p_chain->u.chain32.prod_idx = prod_idx;
614 p_chain->p_prod_elem = p_prod_elem;
615}
616
617/**
618 * qed_chain_pbl_zero_mem(): set chain memory to 0.
619 *
620 * @p_chain: Chain.
621 *
622 * Return: Void.
623 */
624static inline void qed_chain_pbl_zero_mem(struct qed_chain *p_chain)
625{
626 u32 i, page_cnt;
627
628 if (p_chain->mode != QED_CHAIN_MODE_PBL)
629 return;
630
631 page_cnt = qed_chain_get_page_cnt(chain: p_chain);
632
633 for (i = 0; i < page_cnt; i++)
634 memset(p_chain->pbl.pp_addr_tbl[i].virt_addr, 0,
635 p_chain->page_size);
636}
637
638#endif
639

source code of linux/include/linux/qed/qed_chain.h