From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Wed, 24 Nov 2021 20:43:35 +0000 (+0100)
Subject: IB/mthca: Use non-atomic bitmap functions when possible in 'mthca_mr.c'
X-Git-Tag: v6.6.17~8410^2~62
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=675e2694fc6c99effd6f07df296b1d806e49ec88;p=platform%2Fkernel%2Flinux-rpi.git

IB/mthca: Use non-atomic bitmap functions when possible in 'mthca_mr.c'

In 'mthca_buddy_init()', the 'buddy->bits[n]' bitmap has just been
allocated, so no concurrent accesses can occur.

The other accesses to the 'buddy->bits[n]' bitmap are protected by the
'buddy->lock' spinlock, so no concurrent accesses can occur.

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

Link: https://lore.kernel.org/r/a19b88ccdbc03972fd97306b998731814283041f.1637785902.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---

diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c
index 8892fcd..a59100c 100644
--- a/drivers/infiniband/hw/mthca/mthca_mr.c
+++ b/drivers/infiniband/hw/mthca/mthca_mr.c
@@ -101,13 +101,13 @@ static u32 mthca_buddy_alloc(struct mthca_buddy *buddy, int order)
 	return -1;
 
  found:
-	clear_bit(seg, buddy->bits[o]);
+	__clear_bit(seg, buddy->bits[o]);
 	--buddy->num_free[o];
 
 	while (o > order) {
 		--o;
 		seg <<= 1;
-		set_bit(seg ^ 1, buddy->bits[o]);
+		__set_bit(seg ^ 1, buddy->bits[o]);
 		++buddy->num_free[o];
 	}
 
@@ -125,13 +125,13 @@ static void mthca_buddy_free(struct mthca_buddy *buddy, u32 seg, int order)
 	spin_lock(&buddy->lock);
 
 	while (test_bit(seg ^ 1, buddy->bits[order])) {
-		clear_bit(seg ^ 1, buddy->bits[order]);
+		__clear_bit(seg ^ 1, buddy->bits[order]);
 		--buddy->num_free[order];
 		seg >>= 1;
 		++order;
 	}
 
-	set_bit(seg, buddy->bits[order]);
+	__set_bit(seg, buddy->bits[order]);
 	++buddy->num_free[order];
 
 	spin_unlock(&buddy->lock);
@@ -158,7 +158,7 @@ static int mthca_buddy_init(struct mthca_buddy *buddy, int max_order)
 			goto err_out_free;
 	}
 
-	set_bit(0, buddy->bits[buddy->max_order]);
+	__set_bit(0, buddy->bits[buddy->max_order]);
 	buddy->num_free[buddy->max_order] = 1;
 
 	return 0;