Jian-Hong Pan jian-hong@endlessm.com 於 2019年7月11日 週四 下午1:25寫道：
Since each skb in RX ring is reused instead of new allocation, we can treat the DMA in a more efficient way by DMA synchronization.
Signed-off-by: Jian-Hong Pan jian-hong@endlessm.com Cc: stable@vger.kernel.org
Sorry, also forget to place the version difference here
v2: - New patch by following [PATCH v3 1/2] rtw88: pci: Rearrange the memory usage for skb in RX ISR.
v3: - Remove rtw_pci_sync_rx_desc_cpu and call dma_sync_single_for_cpu in rtw_pci_rx_isr directly. - Remove the return value of rtw_pci_sync_rx_desc_device. - Use DMA_FROM_DEVICE instead of PCI_DMA_FROMDEVICE.
v4: - Same as v3.
drivers/net/wireless/realtek/rtw88/pci.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index c415f5e94fed..68fae52151dd 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -206,6 +206,23 @@ static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb, return 0; }
+static void rtw_pci_sync_rx_desc_device(struct rtw_dev *rtwdev, dma_addr_t dma,
struct rtw_pci_rx_ring *rx_ring,u32 idx, u32 desc_sz)+{
struct device *dev = rtwdev->dev;struct rtw_pci_rx_buffer_desc *buf_desc;int buf_sz = RTK_PCI_RX_BUF_SIZE;dma_sync_single_for_device(dev, dma, buf_sz, DMA_FROM_DEVICE);buf_desc = (struct rtw_pci_rx_buffer_desc *)(rx_ring->r.head +idx * desc_sz);memset(buf_desc, 0, sizeof(*buf_desc));buf_desc->buf_size = cpu_to_le16(RTK_PCI_RX_BUF_SIZE);buf_desc->dma = cpu_to_le32(dma);+}
static int rtw_pci_init_rx_ring(struct rtw_dev *rtwdev, struct rtw_pci_rx_ring *rx_ring, u8 desc_size, u32 len) @@ -782,8 +799,8 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, rtw_pci_dma_check(rtwdev, ring, cur_rp); skb = ring->buf[cur_rp]; dma = *((dma_addr_t *)skb->cb);
pci_unmap_single(rtwpci->pdev, dma, RTK_PCI_RX_BUF_SIZE,PCI_DMA_FROMDEVICE);
dma_sync_single_for_cpu(rtwdev->dev, dma, RTK_PCI_RX_BUF_SIZE,DMA_FROM_DEVICE); rx_desc = skb->data; chip->ops->query_rx_desc(rtwdev, rx_desc, &pkt_stat, &rx_status);@@ -818,7 +835,8 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci,
next_rp: /* new skb delivered to mac80211, re-enable original skb DMA */
rtw_pci_reset_rx_desc(rtwdev, skb, ring, cur_rp, buf_desc_sz);
rtw_pci_sync_rx_desc_device(rtwdev, dma, ring, cur_rp,buf_desc_sz); /* host read next element in ring */ if (++cur_rp >= ring->r.len)-- 2.22.0