[PATCH] net: spider_net: Use non-atomic bitmap API when applicable

From: Christophe JAILLET
Date: Sat Nov 27 2021 - 10:21:16 EST


No concurrent access is possible when a bitmap is local to a function.
So prefer the non-atomic functions to save a few cycles.
- replace a 'for' loop by an equivalent non-atomic 'bitmap_fill()' call
- use '__set_bit()'

While at it, clear the 'bitmask' bitmap only when needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
This patch is *not* compile tested. I don't have the needed cross compiling
tool chain.
---
drivers/net/ethernet/toshiba/spider_net.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/toshiba/spider_net.c b/drivers/net/ethernet/toshiba/spider_net.c
index f50f9a43d3ea..f47b8358669d 100644
--- a/drivers/net/ethernet/toshiba/spider_net.c
+++ b/drivers/net/ethernet/toshiba/spider_net.c
@@ -595,24 +595,24 @@ spider_net_set_multi(struct net_device *netdev)
int i;
u32 reg;
struct spider_net_card *card = netdev_priv(netdev);
- DECLARE_BITMAP(bitmask, SPIDER_NET_MULTICAST_HASHES) = {};
+ DECLARE_BITMAP(bitmask, SPIDER_NET_MULTICAST_HASHES);

spider_net_set_promisc(card);

if (netdev->flags & IFF_ALLMULTI) {
- for (i = 0; i < SPIDER_NET_MULTICAST_HASHES; i++) {
- set_bit(i, bitmask);
- }
+ bitmap_fill(bitmask, SPIDER_NET_MULTICAST_HASHES);
goto write_hash;
}

+ bitmap_zero(bitmask, SPIDER_NET_MULTICAST_HASHES);
+
/* well, we know, what the broadcast hash value is: it's xfd
hash = spider_net_get_multicast_hash(netdev, netdev->broadcast); */
- set_bit(0xfd, bitmask);
+ __set_bit(0xfd, bitmask);

netdev_for_each_mc_addr(ha, netdev) {
hash = spider_net_get_multicast_hash(netdev, ha->addr);
- set_bit(hash, bitmask);
+ __set_bit(hash, bitmask);
}

write_hash:
--
2.30.2