linux-kernel - [PATCH 3/3] RDMA/cxgb4: Use non-atomic bitmap functions when possible

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Message-Id: <0c1c4505ca32f5ba4126e3e324041da191513ef2.1637789139.git.christophe.jaillet@wanadoo.fr>
Date:   Wed, 24 Nov 2021 22:40:26 +0100
From:   Christophe JAILLET <christophe.jaillet@...adoo.fr>
To:     bharat@...lsio.com, dledford@...hat.com, jgg@...pe.ca
Cc:     linux-rdma@...r.kernel.org, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>
Subject: [PATCH 3/3] RDMA/cxgb4: Use non-atomic bitmap functions when possible

The accesses to the 'alloc->table' bitmap are protected by the
'alloc->lock' spinlock, so no concurrent accesses can happen.

So prefer the non-atomic '__[set|clear]_bit()' functions to save a few
cycles.

Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
---
 drivers/infiniband/hw/cxgb4/id_table.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/cxgb4/id_table.c b/drivers/infiniband/hw/cxgb4/id_table.c
index e09faa659d68..f64e7e02b129 100644
--- a/drivers/infiniband/hw/cxgb4/id_table.c
+++ b/drivers/infiniband/hw/cxgb4/id_table.c
@@ -59,7 +59,7 @@ u32 c4iw_id_alloc(struct c4iw_id_table *alloc)
 			alloc->last = obj + 1;
 		if (alloc->last >= alloc->max)
 			alloc->last = 0;
-		set_bit(obj, alloc->table);
+		__set_bit(obj, alloc->table);
 		obj += alloc->start;
 	} else
 		obj = -1;
@@ -75,7 +75,7 @@ void c4iw_id_free(struct c4iw_id_table *alloc, u32 obj)
 	obj -= alloc->start;
 
 	spin_lock_irqsave(&alloc->lock, flags);
-	clear_bit(obj, alloc->table);
+	__clear_bit(obj, alloc->table);
 	spin_unlock_irqrestore(&alloc->lock, flags);
 }
 
-- 
2.30.2