[dpdk-stable] patch 'net/qede/base: fix page index for PBL chains' has been queued to LTS release 18.11.6

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.6

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 12/10/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/ca9e7fab8cbd768a945ea6993c4551f63fe7f6c8

Thanks.

Kevin.

---
>From ca9e7fab8cbd768a945ea6993c4551f63fe7f6c8 Mon Sep 17 00:00:00 2001
From: Rasesh Mody <rmody at marvell.com>
Date: Sun, 6 Oct 2019 13:14:01 -0700
Subject: [PATCH] net/qede/base: fix page index for PBL chains

[ upstream commit 766d68ac2d116f5a08de0b8667939408ce362c44 ]

ecore_chain_set_prod/cons() sets the wrong page index in chains with
non-power of 2 page count. Fix ecore_chain_set_prod/cons() for PBL
chains with non power of 2 page count.
Calculate the right page index according to current indexes.

Fixes: ec94dbc57362 ("qede: add base driver")

Signed-off-by: Rasesh Mody <rmody at marvell.com>
---
 drivers/net/qede/base/ecore_chain.h | 84 ++++++++++++++++++++---------
 1 file changed, 58 insertions(+), 26 deletions(-)

diff --git a/drivers/net/qede/base/ecore_chain.h b/drivers/net/qede/base/ecore_chain.h
index 6d0382d3a..c69920be5 100644
--- a/drivers/net/qede/base/ecore_chain.h
+++ b/drivers/net/qede/base/ecore_chain.h
@@ -87,6 +87,6 @@ struct ecore_chain {
 
 		union {
-			struct ecore_chain_pbl_u16	u16;
-			struct ecore_chain_pbl_u32	u32;
+			struct ecore_chain_pbl_u16	pbl_u16;
+			struct ecore_chain_pbl_u32	pbl_u32;
 		} c;
 	} pbl;
@@ -406,5 +406,5 @@ static OSAL_INLINE void *ecore_chain_produce(struct ecore_chain *p_chain)
 		     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 			p_prod_idx = &p_chain->u.chain16.prod_idx;
-			p_prod_page_idx = &p_chain->pbl.c.u16.prod_page_idx;
+			p_prod_page_idx = &p_chain->pbl.c.pbl_u16.prod_page_idx;
 			ecore_chain_advance_page(p_chain, &p_chain->p_prod_elem,
 						 p_prod_idx, p_prod_page_idx);
@@ -415,5 +415,5 @@ static OSAL_INLINE void *ecore_chain_produce(struct ecore_chain *p_chain)
 		     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 			p_prod_idx = &p_chain->u.chain32.prod_idx;
-			p_prod_page_idx = &p_chain->pbl.c.u32.prod_page_idx;
+			p_prod_page_idx = &p_chain->pbl.c.pbl_u32.prod_page_idx;
 			ecore_chain_advance_page(p_chain, &p_chain->p_prod_elem,
 						 p_prod_idx, p_prod_page_idx);
@@ -480,5 +480,5 @@ static OSAL_INLINE void *ecore_chain_consume(struct ecore_chain *p_chain)
 		     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 			p_cons_idx = &p_chain->u.chain16.cons_idx;
-			p_cons_page_idx = &p_chain->pbl.c.u16.cons_page_idx;
+			p_cons_page_idx = &p_chain->pbl.c.pbl_u16.cons_page_idx;
 			ecore_chain_advance_page(p_chain, &p_chain->p_cons_elem,
 						 p_cons_idx, p_cons_page_idx);
@@ -489,5 +489,5 @@ static OSAL_INLINE void *ecore_chain_consume(struct ecore_chain *p_chain)
 		     p_chain->elem_per_page_mask) == p_chain->next_page_mask) {
 			p_cons_idx = &p_chain->u.chain32.cons_idx;
-			p_cons_page_idx = &p_chain->pbl.c.u32.cons_page_idx;
+			p_cons_page_idx = &p_chain->pbl.c.pbl_u32.cons_page_idx;
 			ecore_chain_advance_page(p_chain, &p_chain->p_cons_elem,
 						 p_cons_idx, p_cons_page_idx);
@@ -533,9 +533,9 @@ static OSAL_INLINE void ecore_chain_reset(struct ecore_chain *p_chain)
 
 		if (is_chain_u16(p_chain)) {
-			p_chain->pbl.c.u16.prod_page_idx = (u16)reset_val;
-			p_chain->pbl.c.u16.cons_page_idx = (u16)reset_val;
+			p_chain->pbl.c.pbl_u16.prod_page_idx = (u16)reset_val;
+			p_chain->pbl.c.pbl_u16.cons_page_idx = (u16)reset_val;
 		} else {
-			p_chain->pbl.c.u32.prod_page_idx = reset_val;
-			p_chain->pbl.c.u32.cons_page_idx = reset_val;
+			p_chain->pbl.c.pbl_u32.prod_page_idx = reset_val;
+			p_chain->pbl.c.pbl_u32.cons_page_idx = reset_val;
 		}
 	}
@@ -726,16 +726,32 @@ static OSAL_INLINE void ecore_chain_set_prod(struct ecore_chain *p_chain,
 {
 	if (p_chain->mode == ECORE_CHAIN_MODE_PBL) {
-		/* Use "prod_idx-1" since ecore_chain_produce() advances the
-		 * page index before the producer index when getting to
-		 * "next_page_mask".
+		u32 cur_prod, page_mask, page_cnt, page_diff;
+
+		cur_prod = is_chain_u16(p_chain) ? p_chain->u.chain16.prod_idx
+						 : p_chain->u.chain32.prod_idx;
+
+		/* Assume that number of elements in a page is power of 2 */
+		page_mask = ~p_chain->elem_per_page_mask;
+
+		/* Use "cur_prod - 1" and "prod_idx - 1" since producer index
+		 * reaches the first element of next page before the page index
+		 * is incremented. See ecore_chain_produce().
+		 * Index wrap around is not a problem because the difference
+		 * between current and given producer indexes is always
+		 * positive and lower than the chain's capacity.
 		 */
-		u32 elem_idx =
-			(prod_idx - 1 + p_chain->capacity) % p_chain->capacity;
-		u32 page_idx = elem_idx / p_chain->elem_per_page;
+		page_diff = (((cur_prod - 1) & page_mask) -
+			     ((prod_idx - 1) & page_mask)) /
+			    p_chain->elem_per_page;
 
+		page_cnt = ecore_chain_get_page_cnt(p_chain);
 		if (is_chain_u16(p_chain))
-			p_chain->pbl.c.u16.prod_page_idx = (u16)page_idx;
+			p_chain->pbl.c.pbl_u16.prod_page_idx =
+				(p_chain->pbl.c.pbl_u16.prod_page_idx -
+				 page_diff + page_cnt) % page_cnt;
 		else
-			p_chain->pbl.c.u32.prod_page_idx = page_idx;
+			p_chain->pbl.c.pbl_u32.prod_page_idx =
+				(p_chain->pbl.c.pbl_u32.prod_page_idx -
+				 page_diff + page_cnt) % page_cnt;
 	}
 
@@ -757,16 +773,32 @@ static OSAL_INLINE void ecore_chain_set_cons(struct ecore_chain *p_chain,
 {
 	if (p_chain->mode == ECORE_CHAIN_MODE_PBL) {
-		/* Use "cons_idx-1" since ecore_chain_consume() advances the
-		 * page index before the consumer index when getting to
-		 * "next_page_mask".
+		u32 cur_cons, page_mask, page_cnt, page_diff;
+
+		cur_cons = is_chain_u16(p_chain) ? p_chain->u.chain16.cons_idx
+						 : p_chain->u.chain32.cons_idx;
+
+		/* Assume that number of elements in a page is power of 2 */
+		page_mask = ~p_chain->elem_per_page_mask;
+
+		/* Use "cur_cons - 1" and "cons_idx - 1" since consumer index
+		 * reaches the first element of next page before the page index
+		 * is incremented. See ecore_chain_consume().
+		 * Index wrap around is not a problem because the difference
+		 * between current and given consumer indexes is always
+		 * positive and lower than the chain's capacity.
 		 */
-		u32 elem_idx =
-			(cons_idx - 1 + p_chain->capacity) % p_chain->capacity;
-		u32 page_idx = elem_idx / p_chain->elem_per_page;
+		page_diff = (((cur_cons - 1) & page_mask) -
+			     ((cons_idx - 1) & page_mask)) /
+			    p_chain->elem_per_page;
 
+		page_cnt = ecore_chain_get_page_cnt(p_chain);
 		if (is_chain_u16(p_chain))
-			p_chain->pbl.c.u16.cons_page_idx = (u16)page_idx;
+			p_chain->pbl.c.pbl_u16.cons_page_idx =
+				(p_chain->pbl.c.pbl_u16.cons_page_idx -
+				 page_diff + page_cnt) % page_cnt;
 		else
-			p_chain->pbl.c.u32.cons_page_idx = page_idx;
+			p_chain->pbl.c.pbl_u32.cons_page_idx =
+				(p_chain->pbl.c.pbl_u32.cons_page_idx -
+				 page_diff + page_cnt) % page_cnt;
 	}
 
-- 
2.21.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-12-03 17:29:55.387004259 +0000
+++ 0063-net-qede-base-fix-page-index-for-PBL-chains.patch	2019-12-03 17:29:51.797748974 +0000
@@ -1 +1 @@
-From 766d68ac2d116f5a08de0b8667939408ce362c44 Mon Sep 17 00:00:00 2001
+From ca9e7fab8cbd768a945ea6993c4551f63fe7f6c8 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 766d68ac2d116f5a08de0b8667939408ce362c44 ]
+
@@ -12 +13,0 @@
-Cc: stable at dpdk.org