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 (file)
--- 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;