xref: /linux/include/linux/qed/qed_chain.h (revision 03ab8e6297acd1bc0eedaa050e2a1635c576fd11)
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 
18 enum 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 
29 enum 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 
35 enum 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 
43 struct qed_chain_next {
44 	struct regpair					next_phys;
45 	void						*next_virt;
46 };
47 
48 struct qed_chain_pbl_u16 {
49 	u16						prod_page_idx;
50 	u16						cons_page_idx;
51 };
52 
53 struct qed_chain_pbl_u32 {
54 	u32						prod_page_idx;
55 	u32						cons_page_idx;
56 };
57 
58 struct qed_chain_u16 {
59 	/* Cyclic index of next element to produce/consume */
60 	u16						prod_idx;
61 	u16						cons_idx;
62 };
63 
64 struct qed_chain_u32 {
65 	/* Cyclic index of next element to produce/consume */
66 	u32						prod_idx;
67 	u32						cons_idx;
68 };
69 
70 struct addr_tbl_entry {
71 	void						*virt_addr;
72 	dma_addr_t					dma_map;
73 };
74 
75 struct 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 
148 struct 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 
qed_chain_get_prod_idx(const struct qed_chain * chain)186 static inline u16 qed_chain_get_prod_idx(const struct qed_chain *chain)
187 {
188 	return chain->u.chain16.prod_idx;
189 }
190 
qed_chain_get_cons_idx(const struct qed_chain * chain)191 static inline u16 qed_chain_get_cons_idx(const struct qed_chain *chain)
192 {
193 	return chain->u.chain16.cons_idx;
194 }
195 
qed_chain_get_prod_idx_u32(const struct qed_chain * chain)196 static inline u32 qed_chain_get_prod_idx_u32(const struct qed_chain *chain)
197 {
198 	return chain->u.chain32.prod_idx;
199 }
200 
qed_chain_get_cons_idx_u32(const struct qed_chain * chain)201 static inline u32 qed_chain_get_cons_idx_u32(const struct qed_chain *chain)
202 {
203 	return chain->u.chain32.cons_idx;
204 }
205 
qed_chain_get_elem_used(const struct qed_chain * chain)206 static 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 
qed_chain_get_elem_left(const struct qed_chain * chain)223 static 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 
qed_chain_get_elem_used_u32(const struct qed_chain * chain)228 static 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 
qed_chain_get_elem_left_u32(const struct qed_chain * chain)245 static 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 
qed_chain_get_usable_per_page(const struct qed_chain * chain)250 static inline u16 qed_chain_get_usable_per_page(const struct qed_chain *chain)
251 {
252 	return chain->usable_per_page;
253 }
254 
qed_chain_get_unusable_per_page(const struct qed_chain * chain)255 static inline u8 qed_chain_get_unusable_per_page(const struct qed_chain *chain)
256 {
257 	return chain->elem_unusable;
258 }
259 
qed_chain_get_page_cnt(const struct qed_chain * chain)260 static inline u32 qed_chain_get_page_cnt(const struct qed_chain *chain)
261 {
262 	return chain->page_cnt;
263 }
264 
qed_chain_get_pbl_phys(const struct qed_chain * chain)265 static 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  */
281 static inline void
qed_chain_advance_page(struct qed_chain * p_chain,void ** p_next_elem,void * idx_to_inc,void * page_to_inc)282 qed_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  */
qed_chain_return_produced(struct qed_chain * p_chain)349 static 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  */
qed_chain_produce(struct qed_chain * p_chain)369 static 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_chain->p_prod_elem,
379 					       p_prod_idx, 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_chain->p_prod_elem,
388 					       p_prod_idx, 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  */
qed_chain_get_capacity(struct qed_chain * p_chain)407 static 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  */
qed_chain_recycle_consumed(struct qed_chain * p_chain)422 static 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  */
qed_chain_consume(struct qed_chain * p_chain)440 static 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_chain->p_cons_elem,
450 					       p_cons_idx, 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_chain->p_cons_elem,
459 					       p_cons_idx, 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  */
qed_chain_reset(struct qed_chain * p_chain)478 static 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  */
qed_chain_get_last_elem(struct qed_chain * p_chain)532 static 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;
563 out:
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  */
qed_chain_set_prod(struct qed_chain * p_chain,u32 prod_idx,void * p_prod_elem)576 static 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(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  */
qed_chain_pbl_zero_mem(struct qed_chain * p_chain)624 static 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(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