From c335869fb934ebcccab69315f1cbe7b34f6d9414 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Wed, 8 Apr 2015 18:49:49 -0700 Subject: [PATCH] e100: Use dma_rmb/wmb where appropriate Reduce the CPU overhead for transmit and receive by using lightweight dma_ barriers instead of full barriers where they are applicable. Cc: Jeff Kirsher Signed-off-by: Alexander Duyck Acked-by: Jeff Kirsher Signed-off-by: David S. Miller --- drivers/net/ethernet/intel/e100.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c index 05f88394f9a5..1a450f4b6b12 100644 --- a/drivers/net/ethernet/intel/e100.c +++ b/drivers/net/ethernet/intel/e100.c @@ -899,7 +899,7 @@ static int e100_exec_cb(struct nic *nic, struct sk_buff *skb, /* Order is important otherwise we'll be in a race with h/w: * set S-bit in current first, then clear S-bit in previous. */ cb->command |= cpu_to_le16(cb_s); - wmb(); + dma_wmb(); cb->prev->command &= cpu_to_le16(~cb_s); while (nic->cb_to_send != nic->cb_to_use) { @@ -1843,7 +1843,7 @@ static int e100_tx_clean(struct nic *nic) for (cb = nic->cb_to_clean; cb->status & cpu_to_le16(cb_complete); cb = nic->cb_to_clean = cb->next) { - rmb(); /* read skb after status */ + dma_rmb(); /* read skb after status */ netif_printk(nic, tx_done, KERN_DEBUG, nic->netdev, "cb[%d]->status = 0x%04X\n", (int)(((void*)cb - (void*)nic->cbs)/sizeof(struct cb)), @@ -1993,7 +1993,7 @@ static int e100_rx_indicate(struct nic *nic, struct rx *rx, netif_printk(nic, rx_status, KERN_DEBUG, nic->netdev, "status=0x%04X\n", rfd_status); - rmb(); /* read size after status bit */ + dma_rmb(); /* read size after status bit */ /* If data isn't ready, nothing to indicate */ if (unlikely(!(rfd_status & cb_complete))) { -- 2.39.5