2021-09-26 06:55:37

by Cai,Huoqing

Subject: [PATCH v2] ibmveth: Use dma_alloc_coherent() instead of kmalloc/dma_map_single()

Replacing kmalloc/kfree/dma_map_single/dma_unmap_single()
with dma_alloc_coherent/dma_free_coherent() helps to reduce
code size, and simplify the code, and coherent DMA will not
clear the cache every time.

Signed-off-by: Cai Huoqing <[email protected]>
---
v1->v2: Remove extra change in Kconfig

drivers/net/ethernet/ibm/ibmveth.c | 25 +++++++++----------------
1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 3d9b4f99d357..3aedb680adb8 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -605,17 +605,13 @@ static int ibmveth_open(struct net_device *netdev)
}

rc = -ENOMEM;
- adapter->bounce_buffer =
- kmalloc(netdev->mtu + IBMVETH_BUFF_OH, GFP_KERNEL);
- if (!adapter->bounce_buffer)
- goto out_free_irq;

- adapter->bounce_buffer_dma =
- dma_map_single(&adapter->vdev->dev, adapter->bounce_buffer,
- netdev->mtu + IBMVETH_BUFF_OH, DMA_BIDIRECTIONAL);
- if (dma_mapping_error(dev, adapter->bounce_buffer_dma)) {
- netdev_err(netdev, "unable to map bounce buffer\n");
- goto out_free_bounce_buffer;
+ adapter->bounce_buffer = dma_alloc_coherent(&adapter->vdev->dev,
+ netdev->mtu + IBMVETH_BUFF_OH,
+ &adapter->bounce_buffer_dma, GFP_KERNEL);
+ if (!adapter->bounce_buffer) {
+ netdev_err(netdev, "unable to alloc bounce buffer\n");
+ goto out_free_irq;
}

netdev_dbg(netdev, "initial replenish cycle\n");
@@ -627,8 +623,6 @@ static int ibmveth_open(struct net_device *netdev)

return 0;

-out_free_bounce_buffer:
- kfree(adapter->bounce_buffer);
out_free_irq:
free_irq(netdev->irq, netdev);
out_free_buffer_pools:
@@ -702,10 +696,9 @@ static int ibmveth_close(struct net_device *netdev)
ibmveth_free_buffer_pool(adapter,
&adapter->rx_buff_pool[i]);

- dma_unmap_single(&adapter->vdev->dev, adapter->bounce_buffer_dma,
- adapter->netdev->mtu + IBMVETH_BUFF_OH,
- DMA_BIDIRECTIONAL);
- kfree(adapter->bounce_buffer);
+ dma_free_coherent(&adapter->vdev->dev,
+ adapter->netdev->mtu + IBMVETH_BUFF_OH,
+ adapter->bounce_buffer, adapter->bounce_buffer_dma);

netdev_dbg(netdev, "close complete\n");

--
2.25.1

2021-09-27 12:32:12

by patchwork-bot+netdevbpf

Subject: Re: [PATCH v2] ibmveth: Use dma_alloc_coherent() instead of kmalloc/dma_map_single()

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Sun, 26 Sep 2021 14:52:14 +0800 you wrote:
> Replacing kmalloc/kfree/dma_map_single/dma_unmap_single()
> with dma_alloc_coherent/dma_free_coherent() helps to reduce
> code size, and simplify the code, and coherent DMA will not
> clear the cache every time.
>
> Signed-off-by: Cai Huoqing <[email protected]>
>
> [...]

Here is the summary with links:
- [v2] ibmveth: Use dma_alloc_coherent() instead of kmalloc/dma_map_single()
https://git.kernel.org/netdev/net-next/c/4247ef026937

You are awesome, thank you!
--
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