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net: hns3: use writel() to optimize the barrier operation

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writel() can be used to order I/O vs memory by default when
writing portable drivers. Use writel() to replace wmb() +
writel_relaxed(), and writel() is dma_wmb() + writel_relaxed()
for ARM64, so there is an optimization here because dma_wmb()
is a lighter barrier than wmb().

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yunsheng Lin 2020-09-16 17:33:49 +08:00 committed by David S. Miller
parent 8c30e19460
commit 48ee56fd0b
2 changed files with 3 additions and 8 deletions
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8
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
View file

@ -1398,9 +1398,8 @@ static void hns3_tx_doorbell(struct hns3_enet_ring *ring, int num,
if (!ring->pending_buf)
return;
wmb(); /* Commit all data before submit */
hnae3_queue_xmit(ring->tqp, ring->pending_buf);
writel(ring->pending_buf,
ring->tqp->io_base + HNS3_RING_TX_RING_TAIL_REG);
ring->pending_buf = 0;
WRITE_ONCE(ring->last_to_use, ring->next_to_use);
}
@ -2618,8 +2617,7 @@ static void hns3_nic_alloc_rx_buffers(struct hns3_enet_ring *ring,
ring_ptr_move_fw(ring, next_to_use);
}
wmb(); /* Make all data has been write before submit */
writel_relaxed(i, ring->tqp->io_base + HNS3_RING_RX_RING_HEAD_REG);
writel(i, ring->tqp->io_base + HNS3_RING_RX_RING_HEAD_REG);
}
static bool hns3_page_is_reusable(struct page *page)

3
drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
View file

@ -539,9 +539,6 @@ static inline bool hns3_nic_resetting(struct net_device *netdev)
#define hns3_write_dev(a, reg, value) \
hns3_write_reg((a)->io_base, (reg), (value))
#define hnae3_queue_xmit(tqp, buf_num) writel_relaxed(buf_num, \
(tqp)->io_base + HNS3_RING_TX_RING_TAIL_REG)
#define ring_to_dev(ring) ((ring)->dev)
#define ring_to_netdev(ring) ((ring)->tqp_vector->napi.dev)