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authorDenis Bolotin <dbolotin@marvell.com>2019-01-03 12:02:39 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-02-27 10:08:03 +0100
commita096429cac56f3d4571ae7914f98bd2eb201b5fe (patch)
tree9c1a2e93b3679e5c845eceb6e27087c3d2b50383
parent3abbc145c7f7dd6f2ba3e89a8e2e691fb16e1f85 (diff)
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qed: Fix qed_chain_set_prod() for PBL chains with non power of 2 page count
[ Upstream commit 2d533a9287f2011632977e87ce2783f4c689c984 ] In PBL chains with non power of 2 page count, the producer is not at the beginning of the chain when index is 0 after a wrap. Therefore, after the producer index wrap around, page index should be calculated more carefully. Signed-off-by: Denis Bolotin <dbolotin@marvell.com> Signed-off-by: Ariel Elior <aelior@marvell.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--include/linux/qed/qed_chain.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/qed/qed_chain.h b/include/linux/qed/qed_chain.h
index 59ddf9af909e..2dd0a9ed5b36 100644
--- a/include/linux/qed/qed_chain.h
+++ b/include/linux/qed/qed_chain.h
@@ -663,6 +663,37 @@ out:
static inline void qed_chain_set_prod(struct qed_chain *p_chain,
u32 prod_idx, void *p_prod_elem)
{
+ if (p_chain->mode == QED_CHAIN_MODE_PBL) {
+ 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 qed_chain_produce().
+ * Index wrap around is not a problem because the difference
+ * between current and given producer indices is always
+ * positive and lower than the chain's capacity.
+ */
+ page_diff = (((cur_prod - 1) & page_mask) -
+ ((prod_idx - 1) & page_mask)) /
+ p_chain->elem_per_page;
+
+ page_cnt = qed_chain_get_page_cnt(p_chain);
+ if (is_chain_u16(p_chain))
+ p_chain->pbl.c.u16.prod_page_idx =
+ (p_chain->pbl.c.u16.prod_page_idx -
+ page_diff + page_cnt) % page_cnt;
+ else
+ p_chain->pbl.c.u32.prod_page_idx =
+ (p_chain->pbl.c.u32.prod_page_idx -
+ page_diff + page_cnt) % page_cnt;
+ }
+
if (is_chain_u16(p_chain))
p_chain->u.chain16.prod_idx = (u16) prod_idx;
else