Each skb as the element in RX ring was expected with sized buffer 8216 (RTK_PCI_RX_BUF_SIZE) bytes. However, the skb buffer's true size is 16640 bytes for alignment after allocated, x86_64 for example. And, the difference will be enlarged 512 times (RTK_MAX_RX_DESC_NUM). To prevent that much wasted memory, this patch follows David's suggestion [1] and uses general buffer arrays, instead of skbs as the elements in RX ring.
[1] https://www.spinics.net/lists/linux-wireless/msg187870.html Signed-off-by: Jian-Hong Pan <jian-h...@endlessm.com> Cc: <sta...@vger.kernel.org> --- drivers/net/wireless/realtek/rtw88/pci.c | 132 +++++++++++++---------- drivers/net/wireless/realtek/rtw88/pci.h | 2 +- 2 files changed, 75 insertions(+), 59 deletions(-) diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index 23dd06afef3d..e953010f0179 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -111,25 +111,49 @@ static void rtw_pci_free_tx_ring(struct rtw_dev *rtwdev, tx_ring->r.head = NULL; } +static struct rtw_pci_rx_buffer_desc *rtw_pci_get_rx_desc( + struct rtw_pci_rx_ring *rx_ring, + u32 idx) +{ + struct rtw_pci_rx_buffer_desc *buf_desc; + u32 desc_sz = rx_ring->r.desc_size; + + buf_desc = (struct rtw_pci_rx_buffer_desc *)(rx_ring->r.head + + idx * desc_sz); + return buf_desc; +} + +static dma_addr_t rtw_pci_get_rx_bufdma(struct rtw_pci_rx_ring *rx_ring, + u32 idx) +{ + struct rtw_pci_rx_buffer_desc *buf_desc; + dma_addr_t dma; + + buf_desc = rtw_pci_get_rx_desc(rx_ring, idx); + dma = le32_to_cpu(buf_desc->dma); + + return dma; +} + static void rtw_pci_free_rx_ring(struct rtw_dev *rtwdev, struct rtw_pci_rx_ring *rx_ring) { struct pci_dev *pdev = to_pci_dev(rtwdev->dev); - struct sk_buff *skb; + u8 *buf; dma_addr_t dma; u8 *head = rx_ring->r.head; int buf_sz = RTK_PCI_RX_BUF_SIZE; int ring_sz = rx_ring->r.desc_size * rx_ring->r.len; - int i; + u32 i; for (i = 0; i < rx_ring->r.len; i++) { - skb = rx_ring->buf[i]; - if (!skb) + buf = rx_ring->buf[i]; + if (!buf) continue; - dma = *((dma_addr_t *)skb->cb); - pci_unmap_single(pdev, dma, buf_sz, PCI_DMA_FROMDEVICE); - dev_kfree_skb(skb); + dma = rtw_pci_get_rx_bufdma(rx_ring, i); + pci_unmap_single(pdev, dma, buf_sz, DMA_FROM_DEVICE); + devm_kfree(rtwdev->dev, buf); rx_ring->buf[i] = NULL; } @@ -180,27 +204,24 @@ static int rtw_pci_init_tx_ring(struct rtw_dev *rtwdev, return 0; } -static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb, - struct rtw_pci_rx_ring *rx_ring, - u32 idx, u32 desc_sz) +static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, u8 *buf, + struct rtw_pci_rx_ring *rx_ring, u32 idx) { struct pci_dev *pdev = to_pci_dev(rtwdev->dev); struct rtw_pci_rx_buffer_desc *buf_desc; int buf_sz = RTK_PCI_RX_BUF_SIZE; dma_addr_t dma; - if (!skb) + if (!buf) return -EINVAL; - dma = pci_map_single(pdev, skb->data, buf_sz, PCI_DMA_FROMDEVICE); + dma = pci_map_single(pdev, buf, buf_sz, DMA_FROM_DEVICE); if (pci_dma_mapping_error(pdev, dma)) return -EBUSY; - *((dma_addr_t *)skb->cb) = dma; - buf_desc = (struct rtw_pci_rx_buffer_desc *)(rx_ring->r.head + - idx * desc_sz); - memset(buf_desc, 0, sizeof(*buf_desc)); + buf_desc = rtw_pci_get_rx_desc(rx_ring, idx); buf_desc->buf_size = cpu_to_le16(RTK_PCI_RX_BUF_SIZE); + buf_desc->total_pkt_size = cpu_to_le16(0); buf_desc->dma = cpu_to_le32(dma); return 0; @@ -208,7 +229,7 @@ static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb, 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) + u32 idx) { struct device *dev = rtwdev->dev; struct rtw_pci_rx_buffer_desc *buf_desc; @@ -216,10 +237,9 @@ static void rtw_pci_sync_rx_desc_device(struct rtw_dev *rtwdev, dma_addr_t dma, 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 = rtw_pci_get_rx_desc(rx_ring, idx); buf_desc->buf_size = cpu_to_le16(RTK_PCI_RX_BUF_SIZE); + buf_desc->total_pkt_size = cpu_to_le16(0); buf_desc->dma = cpu_to_le32(dma); } @@ -228,12 +248,12 @@ static int rtw_pci_init_rx_ring(struct rtw_dev *rtwdev, u8 desc_size, u32 len) { struct pci_dev *pdev = to_pci_dev(rtwdev->dev); - struct sk_buff *skb = NULL; + u8 *buf = NULL; dma_addr_t dma; u8 *head; int ring_sz = desc_size * len; int buf_sz = RTK_PCI_RX_BUF_SIZE; - int i, allocated; + u32 i, allocated; int ret = 0; head = pci_zalloc_consistent(pdev, ring_sz, &dma); @@ -242,41 +262,39 @@ static int rtw_pci_init_rx_ring(struct rtw_dev *rtwdev, return -ENOMEM; } rx_ring->r.head = head; + rx_ring->r.dma = dma; + rx_ring->r.len = len; + rx_ring->r.desc_size = desc_size; + rx_ring->r.wp = 0; + rx_ring->r.rp = 0; for (i = 0; i < len; i++) { - skb = dev_alloc_skb(buf_sz); - if (!skb) { + buf = devm_kzalloc(rtwdev->dev, buf_sz, GFP_ATOMIC); + if (!buf) { allocated = i; ret = -ENOMEM; goto err_out; } - memset(skb->data, 0, buf_sz); - rx_ring->buf[i] = skb; - ret = rtw_pci_reset_rx_desc(rtwdev, skb, rx_ring, i, desc_size); + rx_ring->buf[i] = buf; + ret = rtw_pci_reset_rx_desc(rtwdev, buf, rx_ring, i); if (ret) { allocated = i; - dev_kfree_skb_any(skb); + devm_kfree(rtwdev->dev, buf); goto err_out; } } - rx_ring->r.dma = dma; - rx_ring->r.len = len; - rx_ring->r.desc_size = desc_size; - rx_ring->r.wp = 0; - rx_ring->r.rp = 0; - return 0; err_out: for (i = 0; i < allocated; i++) { - skb = rx_ring->buf[i]; - if (!skb) + buf = rx_ring->buf[i]; + if (!buf) continue; - dma = *((dma_addr_t *)skb->cb); - pci_unmap_single(pdev, dma, buf_sz, PCI_DMA_FROMDEVICE); - dev_kfree_skb_any(skb); + dma = rtw_pci_get_rx_bufdma(rx_ring, i); + pci_unmap_single(pdev, dma, buf_sz, DMA_FROM_DEVICE); + devm_kfree(rtwdev->dev, buf); rx_ring->buf[i] = NULL; } pci_free_consistent(pdev, ring_sz, head, dma); @@ -776,13 +794,12 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, struct rtw_pci_rx_ring *ring; struct rtw_rx_pkt_stat pkt_stat; struct ieee80211_rx_status rx_status; - struct sk_buff *skb, *new; + struct sk_buff *skb; u32 cur_wp, cur_rp, tmp; u32 count; u32 pkt_offset; u32 pkt_desc_sz = chip->rx_pkt_desc_sz; - u32 buf_desc_sz = chip->rx_buf_desc_sz; - u32 new_len; + u32 len; u8 *rx_desc; dma_addr_t dma; @@ -799,11 +816,11 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, cur_rp = ring->r.rp; while (count--) { rtw_pci_dma_check(rtwdev, ring, cur_rp); - skb = ring->buf[cur_rp]; - dma = *((dma_addr_t *)skb->cb); + /* buffer is already filled as rx_desc */ + rx_desc = ring->buf[cur_rp]; + dma = rtw_pci_get_rx_bufdma(ring, cur_rp); 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); /* offset from rx_desc to payload */ @@ -813,32 +830,31 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, /* allocate a new skb for this frame, * discard the frame if none available */ - new_len = pkt_stat.pkt_len + pkt_offset; - new = dev_alloc_skb(new_len); - if (WARN_ONCE(!new, "rx routine starvation\n")) + len = pkt_stat.pkt_len + pkt_offset; + skb = dev_alloc_skb(len); + if (WARN_ONCE(!skb, "rx routine starvation\n")) goto next_rp; /* put the DMA data including rx_desc from phy to new skb */ - skb_put_data(new, skb->data, new_len); + skb_put_data(skb, rx_desc, len); if (pkt_stat.is_c2h) { /* pass rx_desc & offset for further operation */ - *((u32 *)new->cb) = pkt_offset; - skb_queue_tail(&rtwdev->c2h_queue, new); + *((u32 *)skb->cb) = pkt_offset; + skb_queue_tail(&rtwdev->c2h_queue, skb); ieee80211_queue_work(rtwdev->hw, &rtwdev->c2h_work); } else { /* remove rx_desc */ - skb_pull(new, pkt_offset); + skb_pull(skb, pkt_offset); - rtw_rx_stats(rtwdev, pkt_stat.vif, new); - memcpy(new->cb, &rx_status, sizeof(rx_status)); - ieee80211_rx_irqsafe(rtwdev->hw, new); + rtw_rx_stats(rtwdev, pkt_stat.vif, skb); + memcpy(skb->cb, &rx_status, sizeof(rx_status)); + ieee80211_rx_irqsafe(rtwdev->hw, skb); } next_rp: - /* new skb delivered to mac80211, re-enable original skb DMA */ - rtw_pci_sync_rx_desc_device(rtwdev, dma, ring, cur_rp, - buf_desc_sz); + /* new skb delivered to mac80211, re-enable original buf DMA */ + rtw_pci_sync_rx_desc_device(rtwdev, dma, ring, cur_rp); /* host read next element in ring */ if (++cur_rp >= ring->r.len) diff --git a/drivers/net/wireless/realtek/rtw88/pci.h b/drivers/net/wireless/realtek/rtw88/pci.h index 87824a4caba9..283685421a64 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.h +++ b/drivers/net/wireless/realtek/rtw88/pci.h @@ -174,7 +174,7 @@ struct rtw_pci_rx_buffer_desc { struct rtw_pci_rx_ring { struct rtw_pci_ring r; - struct sk_buff *buf[RTK_MAX_RX_DESC_NUM]; + u8 *buf[RTK_MAX_RX_DESC_NUM]; }; #define RX_TAG_MAX 8192 -- 2.22.0
