| Message ID | 20190709102059.7036-2-jian-hong@endlessm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | rtw88/pci: Rearrange the memory usage for skb in RX ISR | expand |
On Tue, Jul 09, 2019 at 06:21:01PM +0800, Jian-Hong Pan wrote: > 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> > --- > drivers/net/wireless/realtek/rtw88/pci.c | 35 ++++++++++++++++++++++-- > 1 file changed, 32 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c > index e9fe3ad896c8..28ca76f71dfe 100644 > --- a/drivers/net/wireless/realtek/rtw88/pci.c > +++ b/drivers/net/wireless/realtek/rtw88/pci.c > @@ -206,6 +206,35 @@ static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb, > return 0; > } > > +static int rtw_pci_sync_rx_desc_cpu(struct rtw_dev *rtwdev, dma_addr_t dma) > +{ > + struct device *dev = rtwdev->dev; > + int buf_sz = RTK_PCI_RX_BUF_SIZE; > + > + dma_sync_single_for_cpu(dev, dma, buf_sz, PCI_DMA_FROMDEVICE); > + > + return 0; > +} No need to return a value from this helper. In fact I'm not even sure you need the helper at all. Also please use the DMA_FROM_DEVICE constant instead of the deprecated PCI variant. > +static int 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, PCI_DMA_FROMDEVICE); > + > + 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); > + > + return 0; > +} Same comment on the PCI constant and the return value here.
diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index e9fe3ad896c8..28ca76f71dfe 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -206,6 +206,35 @@ static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb, return 0; } +static int rtw_pci_sync_rx_desc_cpu(struct rtw_dev *rtwdev, dma_addr_t dma) +{ + struct device *dev = rtwdev->dev; + int buf_sz = RTK_PCI_RX_BUF_SIZE; + + dma_sync_single_for_cpu(dev, dma, buf_sz, PCI_DMA_FROMDEVICE); + + return 0; +} + +static int 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, PCI_DMA_FROMDEVICE); + + 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); + + return 0; +} + 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 +811,7 @@ 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); + rtw_pci_sync_rx_desc_cpu(rtwdev, dma); rx_desc = skb->data; chip->ops->query_rx_desc(rtwdev, rx_desc, &pkt_stat, &rx_status); @@ -818,7 +846,8 @@ 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)
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> --- drivers/net/wireless/realtek/rtw88/pci.c | 35 ++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 3 deletions(-)