sfc: Reduce size of efx_rx_buffer by unionising skb and page
[bwh: Forward-ported to net-next-2.6.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
This commit is contained in:
parent
5b2c4dd2ec
commit
8ba5366ada
drivers/net/sfc
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@ -216,13 +216,17 @@ struct efx_tx_queue {
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* If both this and skb are %NULL, the buffer slot is currently free.
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* @data: Pointer to ethernet header
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* @len: Buffer length, in bytes.
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* @is_page: Indicates if @page is valid. If false, @skb is valid.
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*/
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struct efx_rx_buffer {
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dma_addr_t dma_addr;
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struct sk_buff *skb;
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struct page *page;
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union {
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struct sk_buff *skb;
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struct page *page;
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} u;
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char *data;
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unsigned int len;
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bool is_page;
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};
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/**
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@ -129,6 +129,7 @@ static int efx_init_rx_buffers_skb(struct efx_rx_queue *rx_queue)
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struct efx_nic *efx = rx_queue->efx;
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struct net_device *net_dev = efx->net_dev;
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struct efx_rx_buffer *rx_buf;
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struct sk_buff *skb;
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int skb_len = efx->rx_buffer_len;
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unsigned index, count;
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@ -136,24 +137,24 @@ static int efx_init_rx_buffers_skb(struct efx_rx_queue *rx_queue)
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index = rx_queue->added_count & rx_queue->ptr_mask;
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rx_buf = efx_rx_buffer(rx_queue, index);
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rx_buf->skb = netdev_alloc_skb(net_dev, skb_len);
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if (unlikely(!rx_buf->skb))
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rx_buf->u.skb = skb = netdev_alloc_skb(net_dev, skb_len);
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if (unlikely(!skb))
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return -ENOMEM;
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rx_buf->page = NULL;
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/* Adjust the SKB for padding and checksum */
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skb_reserve(rx_buf->skb, NET_IP_ALIGN);
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skb_reserve(skb, NET_IP_ALIGN);
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rx_buf->data = (char *)skb->data;
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rx_buf->len = skb_len - NET_IP_ALIGN;
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rx_buf->data = (char *)rx_buf->skb->data;
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rx_buf->skb->ip_summed = CHECKSUM_UNNECESSARY;
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rx_buf->is_page = false;
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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rx_buf->dma_addr = pci_map_single(efx->pci_dev,
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rx_buf->data, rx_buf->len,
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PCI_DMA_FROMDEVICE);
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if (unlikely(pci_dma_mapping_error(efx->pci_dev,
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rx_buf->dma_addr))) {
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dev_kfree_skb_any(rx_buf->skb);
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rx_buf->skb = NULL;
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dev_kfree_skb_any(skb);
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rx_buf->u.skb = NULL;
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return -EIO;
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}
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@ -211,10 +212,10 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
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index = rx_queue->added_count & rx_queue->ptr_mask;
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rx_buf = efx_rx_buffer(rx_queue, index);
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rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN;
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rx_buf->skb = NULL;
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rx_buf->page = page;
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rx_buf->u.page = page;
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rx_buf->data = page_addr + EFX_PAGE_IP_ALIGN;
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rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
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rx_buf->is_page = true;
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++rx_queue->added_count;
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++rx_queue->alloc_page_count;
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++state->refcnt;
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@ -235,19 +236,17 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
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static void efx_unmap_rx_buffer(struct efx_nic *efx,
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struct efx_rx_buffer *rx_buf)
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{
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if (rx_buf->page) {
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if (rx_buf->is_page && rx_buf->u.page) {
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struct efx_rx_page_state *state;
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EFX_BUG_ON_PARANOID(rx_buf->skb);
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state = page_address(rx_buf->page);
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state = page_address(rx_buf->u.page);
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if (--state->refcnt == 0) {
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pci_unmap_page(efx->pci_dev,
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state->dma_addr,
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efx_rx_buf_size(efx),
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PCI_DMA_FROMDEVICE);
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}
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} else if (likely(rx_buf->skb)) {
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} else if (!rx_buf->is_page && rx_buf->u.skb) {
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pci_unmap_single(efx->pci_dev, rx_buf->dma_addr,
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rx_buf->len, PCI_DMA_FROMDEVICE);
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}
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@ -256,12 +255,12 @@ static void efx_unmap_rx_buffer(struct efx_nic *efx,
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static void efx_free_rx_buffer(struct efx_nic *efx,
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struct efx_rx_buffer *rx_buf)
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{
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if (rx_buf->page) {
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__free_pages(rx_buf->page, efx->rx_buffer_order);
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rx_buf->page = NULL;
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} else if (likely(rx_buf->skb)) {
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dev_kfree_skb_any(rx_buf->skb);
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rx_buf->skb = NULL;
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if (rx_buf->is_page && rx_buf->u.page) {
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__free_pages(rx_buf->u.page, efx->rx_buffer_order);
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rx_buf->u.page = NULL;
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} else if (!rx_buf->is_page && rx_buf->u.skb) {
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dev_kfree_skb_any(rx_buf->u.skb);
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rx_buf->u.skb = NULL;
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}
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}
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@ -277,7 +276,7 @@ static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
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static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
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struct efx_rx_buffer *rx_buf)
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{
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struct efx_rx_page_state *state = page_address(rx_buf->page);
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struct efx_rx_page_state *state = page_address(rx_buf->u.page);
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struct efx_rx_buffer *new_buf;
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unsigned fill_level, index;
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@ -292,16 +291,16 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
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}
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++state->refcnt;
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get_page(rx_buf->page);
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get_page(rx_buf->u.page);
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index = rx_queue->added_count & rx_queue->ptr_mask;
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new_buf = efx_rx_buffer(rx_queue, index);
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new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
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new_buf->skb = NULL;
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new_buf->page = rx_buf->page;
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new_buf->u.page = rx_buf->u.page;
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new_buf->data = (void *)
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((__force unsigned long)rx_buf->data ^ (PAGE_SIZE >> 1));
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new_buf->len = rx_buf->len;
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new_buf->is_page = true;
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++rx_queue->added_count;
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}
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@ -315,16 +314,15 @@ static void efx_recycle_rx_buffer(struct efx_channel *channel,
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struct efx_rx_buffer *new_buf;
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unsigned index;
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if (rx_buf->page != NULL && efx->rx_buffer_len <= EFX_RX_HALF_PAGE &&
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page_count(rx_buf->page) == 1)
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if (rx_buf->is_page && efx->rx_buffer_len <= EFX_RX_HALF_PAGE &&
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page_count(rx_buf->u.page) == 1)
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efx_resurrect_rx_buffer(rx_queue, rx_buf);
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index = rx_queue->added_count & rx_queue->ptr_mask;
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new_buf = efx_rx_buffer(rx_queue, index);
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memcpy(new_buf, rx_buf, sizeof(*new_buf));
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rx_buf->page = NULL;
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rx_buf->skb = NULL;
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rx_buf->u.page = NULL;
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++rx_queue->added_count;
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}
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@ -428,7 +426,7 @@ static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
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* data at the end of the skb will be trashed. So
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* we have no choice but to leak the fragment.
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*/
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*leak_packet = (rx_buf->skb != NULL);
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*leak_packet = !rx_buf->is_page;
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efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
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} else {
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if (net_ratelimit())
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@ -454,13 +452,12 @@ static void efx_rx_packet_gro(struct efx_channel *channel,
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gro_result_t gro_result;
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/* Pass the skb/page into the GRO engine */
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if (rx_buf->page) {
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if (rx_buf->is_page) {
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struct efx_nic *efx = channel->efx;
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struct page *page = rx_buf->page;
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struct page *page = rx_buf->u.page;
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struct sk_buff *skb;
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EFX_BUG_ON_PARANOID(rx_buf->skb);
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rx_buf->page = NULL;
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rx_buf->u.page = NULL;
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skb = napi_get_frags(napi);
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if (!skb) {
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@ -487,11 +484,10 @@ static void efx_rx_packet_gro(struct efx_channel *channel,
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gro_result = napi_gro_frags(napi);
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} else {
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struct sk_buff *skb = rx_buf->skb;
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struct sk_buff *skb = rx_buf->u.skb;
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EFX_BUG_ON_PARANOID(!skb);
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EFX_BUG_ON_PARANOID(!checksummed);
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rx_buf->skb = NULL;
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rx_buf->u.skb = NULL;
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gro_result = napi_gro_receive(napi, skb);
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}
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@ -514,8 +510,6 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
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rx_buf = efx_rx_buffer(rx_queue, index);
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EFX_BUG_ON_PARANOID(!rx_buf->data);
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EFX_BUG_ON_PARANOID(rx_buf->skb && rx_buf->page);
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EFX_BUG_ON_PARANOID(!(rx_buf->skb || rx_buf->page));
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/* This allows the refill path to post another buffer.
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* EFX_RXD_HEAD_ROOM ensures that the slot we are using
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@ -587,32 +581,32 @@ void __efx_rx_packet(struct efx_channel *channel,
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return;
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}
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if (rx_buf->skb) {
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prefetch(skb_shinfo(rx_buf->skb));
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if (!rx_buf->is_page) {
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skb = rx_buf->u.skb;
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skb_reserve(rx_buf->skb, efx->type->rx_buffer_hash_size);
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skb_put(rx_buf->skb, rx_buf->len);
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prefetch(skb_shinfo(skb));
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skb_reserve(skb, efx->type->rx_buffer_hash_size);
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skb_put(skb, rx_buf->len);
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if (efx->net_dev->features & NETIF_F_RXHASH)
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rx_buf->skb->rxhash = efx_rx_buf_hash(rx_buf);
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skb->rxhash = efx_rx_buf_hash(rx_buf);
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/* Move past the ethernet header. rx_buf->data still points
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* at the ethernet header */
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rx_buf->skb->protocol = eth_type_trans(rx_buf->skb,
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efx->net_dev);
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skb->protocol = eth_type_trans(skb, efx->net_dev);
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skb_record_rx_queue(rx_buf->skb, channel->channel);
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skb_record_rx_queue(skb, channel->channel);
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}
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if (likely(checksummed || rx_buf->page)) {
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if (likely(checksummed || rx_buf->is_page)) {
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efx_rx_packet_gro(channel, rx_buf, checksummed);
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return;
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}
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/* We now own the SKB */
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skb = rx_buf->skb;
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rx_buf->skb = NULL;
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EFX_BUG_ON_PARANOID(!skb);
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skb = rx_buf->u.skb;
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rx_buf->u.skb = NULL;
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/* Set the SKB flags */
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skb_checksum_none_assert(skb);
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