From a526f140b22131376b0e49577210e6af73e2b89f Mon Sep 17 00:00:00 2001 From: Steve Hodgson Date: Thu, 24 Feb 2011 23:45:16 +0000 Subject: [PATCH] sfc: Reduce size of efx_rx_buffer further by removing data member Instead calculate the KVA of receive data. It's not like it's a hard sum. [bwh: Fixed to work with GRO.] Signed-off-by: Ben Hutchings --- drivers/net/sfc/net_driver.h | 2 -- drivers/net/sfc/rx.c | 50 ++++++++++++++++++++---------------- 2 files changed, 28 insertions(+), 24 deletions(-) diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h index 59ff32ac7ec6..5b001c1c73d4 100644 --- a/drivers/net/sfc/net_driver.h +++ b/drivers/net/sfc/net_driver.h @@ -214,7 +214,6 @@ struct efx_tx_queue { * If both this and page are %NULL, the buffer slot is currently free. * @page: The associated page buffer, if any. * If both this and skb are %NULL, the buffer slot is currently free. - * @data: Pointer to ethernet header * @len: Buffer length, in bytes. * @is_page: Indicates if @page is valid. If false, @skb is valid. */ @@ -224,7 +223,6 @@ struct efx_rx_buffer { struct sk_buff *skb; struct page *page; } u; - char *data; unsigned int len; bool is_page; }; diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c index bcbd2ec2d92a..81bec873e9d3 100644 --- a/drivers/net/sfc/rx.c +++ b/drivers/net/sfc/rx.c @@ -89,24 +89,37 @@ static unsigned int rx_refill_limit = 95; */ #define EFX_RXD_HEAD_ROOM 2 -static inline unsigned int efx_rx_buf_offset(struct efx_rx_buffer *buf) +/* Offset of ethernet header within page */ +static inline unsigned int efx_rx_buf_offset(struct efx_nic *efx, + struct efx_rx_buffer *buf) { /* Offset is always within one page, so we don't need to consider * the page order. */ - return (__force unsigned long) buf->data & (PAGE_SIZE - 1); + return (((__force unsigned long) buf->dma_addr & (PAGE_SIZE - 1)) + + efx->type->rx_buffer_hash_size); } static inline unsigned int efx_rx_buf_size(struct efx_nic *efx) { return PAGE_SIZE << efx->rx_buffer_order; } -static inline u32 efx_rx_buf_hash(struct efx_rx_buffer *buf) +static u8 *efx_rx_buf_eh(struct efx_nic *efx, struct efx_rx_buffer *buf) { + if (buf->is_page) + return page_address(buf->u.page) + efx_rx_buf_offset(efx, buf); + else + return ((u8 *)buf->u.skb->data + + efx->type->rx_buffer_hash_size); +} + +static inline u32 efx_rx_buf_hash(const u8 *eh) +{ + /* The ethernet header is always directly after any hash. */ #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || NET_IP_ALIGN % 4 == 0 - return __le32_to_cpup((const __le32 *)(buf->data - 4)); + return __le32_to_cpup((const __le32 *)(eh - 4)); #else - const u8 *data = (const u8 *)(buf->data - 4); + const u8 *data = eh - 4; return ((u32)data[0] | (u32)data[1] << 8 | (u32)data[2] << 16 | @@ -143,13 +156,12 @@ static int efx_init_rx_buffers_skb(struct efx_rx_queue *rx_queue) /* Adjust the SKB for padding and checksum */ skb_reserve(skb, NET_IP_ALIGN); - rx_buf->data = (char *)skb->data; rx_buf->len = skb_len - NET_IP_ALIGN; rx_buf->is_page = false; skb->ip_summed = CHECKSUM_UNNECESSARY; rx_buf->dma_addr = pci_map_single(efx->pci_dev, - rx_buf->data, rx_buf->len, + skb->data, rx_buf->len, PCI_DMA_FROMDEVICE); if (unlikely(pci_dma_mapping_error(efx->pci_dev, rx_buf->dma_addr))) { @@ -213,7 +225,6 @@ static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue) rx_buf = efx_rx_buffer(rx_queue, index); rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN; rx_buf->u.page = page; - rx_buf->data = page_addr + EFX_PAGE_IP_ALIGN; rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN; rx_buf->is_page = true; ++rx_queue->added_count; @@ -297,8 +308,6 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue, new_buf = efx_rx_buffer(rx_queue, index); new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1); new_buf->u.page = rx_buf->u.page; - new_buf->data = (void *) - ((__force unsigned long)rx_buf->data ^ (PAGE_SIZE >> 1)); new_buf->len = rx_buf->len; new_buf->is_page = true; ++rx_queue->added_count; @@ -446,7 +455,7 @@ static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue, */ static void efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf, - bool checksummed) + const u8 *eh, bool checksummed) { struct napi_struct *napi = &channel->napi_str; gro_result_t gro_result; @@ -466,11 +475,11 @@ static void efx_rx_packet_gro(struct efx_channel *channel, } if (efx->net_dev->features & NETIF_F_RXHASH) - skb->rxhash = efx_rx_buf_hash(rx_buf); + skb->rxhash = efx_rx_buf_hash(eh); skb_shinfo(skb)->frags[0].page = page; skb_shinfo(skb)->frags[0].page_offset = - efx_rx_buf_offset(rx_buf); + efx_rx_buf_offset(efx, rx_buf); skb_shinfo(skb)->frags[0].size = rx_buf->len; skb_shinfo(skb)->nr_frags = 1; @@ -509,7 +518,6 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index, bool leak_packet = false; rx_buf = efx_rx_buffer(rx_queue, index); - EFX_BUG_ON_PARANOID(!rx_buf->data); /* This allows the refill path to post another buffer. * EFX_RXD_HEAD_ROOM ensures that the slot we are using @@ -548,12 +556,12 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index, /* Prefetch nice and early so data will (hopefully) be in cache by * the time we look at it. */ - prefetch(rx_buf->data); + prefetch(efx_rx_buf_eh(efx, rx_buf)); /* Pipeline receives so that we give time for packet headers to be * prefetched into cache. */ - rx_buf->len = len; + rx_buf->len = len - efx->type->rx_buffer_hash_size; out: if (channel->rx_pkt) __efx_rx_packet(channel, @@ -568,15 +576,13 @@ void __efx_rx_packet(struct efx_channel *channel, { struct efx_nic *efx = channel->efx; struct sk_buff *skb; - - rx_buf->data += efx->type->rx_buffer_hash_size; - rx_buf->len -= efx->type->rx_buffer_hash_size; + u8 *eh = efx_rx_buf_eh(efx, rx_buf); /* If we're in loopback test, then pass the packet directly to the * loopback layer, and free the rx_buf here */ if (unlikely(efx->loopback_selftest)) { - efx_loopback_rx_packet(efx, rx_buf->data, rx_buf->len); + efx_loopback_rx_packet(efx, eh, rx_buf->len); efx_free_rx_buffer(efx, rx_buf); return; } @@ -590,7 +596,7 @@ void __efx_rx_packet(struct efx_channel *channel, skb_put(skb, rx_buf->len); if (efx->net_dev->features & NETIF_F_RXHASH) - skb->rxhash = efx_rx_buf_hash(rx_buf); + skb->rxhash = efx_rx_buf_hash(eh); /* Move past the ethernet header. rx_buf->data still points * at the ethernet header */ @@ -600,7 +606,7 @@ void __efx_rx_packet(struct efx_channel *channel, } if (likely(checksummed || rx_buf->is_page)) { - efx_rx_packet_gro(channel, rx_buf, checksummed); + efx_rx_packet_gro(channel, rx_buf, eh, checksummed); return; }