diff options
Diffstat (limited to 'drivers/net/sfc/tx.c')
| -rw-r--r-- | drivers/net/sfc/tx.c | 1120 |
1 files changed, 0 insertions, 1120 deletions
diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c deleted file mode 100644 index 5e8374ab28e..00000000000 --- a/drivers/net/sfc/tx.c +++ /dev/null @@ -1,1120 +0,0 @@ -/**************************************************************************** - * Driver for Solarflare Solarstorm network controllers and boards - * Copyright 2005-2006 Fen Systems Ltd. - * Copyright 2005-2008 Solarflare Communications Inc. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published - * by the Free Software Foundation, incorporated herein by reference. - */ - -#include <linux/pci.h> -#include <linux/tcp.h> -#include <linux/ip.h> -#include <linux/in.h> -#include <linux/if_ether.h> -#include <linux/highmem.h> -#include "net_driver.h" -#include "tx.h" -#include "efx.h" -#include "falcon.h" -#include "workarounds.h" - -/* - * TX descriptor ring full threshold - * - * The tx_queue descriptor ring fill-level must fall below this value - * before we restart the netif queue - */ -#define EFX_NETDEV_TX_THRESHOLD(_tx_queue) \ - (_tx_queue->efx->type->txd_ring_mask / 2u) - -/* We want to be able to nest calls to netif_stop_queue(), since each - * channel can have an individual stop on the queue. - */ -void efx_stop_queue(struct efx_nic *efx) -{ - spin_lock_bh(&efx->netif_stop_lock); - EFX_TRACE(efx, "stop TX queue\n"); - - atomic_inc(&efx->netif_stop_count); - netif_stop_queue(efx->net_dev); - - spin_unlock_bh(&efx->netif_stop_lock); -} - -/* Wake netif's TX queue - * We want to be able to nest calls to netif_stop_queue(), since each - * channel can have an individual stop on the queue. - */ -inline void efx_wake_queue(struct efx_nic *efx) -{ - local_bh_disable(); - if (atomic_dec_and_lock(&efx->netif_stop_count, - &efx->netif_stop_lock)) { - EFX_TRACE(efx, "waking TX queue\n"); - netif_wake_queue(efx->net_dev); - spin_unlock(&efx->netif_stop_lock); - } - local_bh_enable(); -} - -static inline void efx_dequeue_buffer(struct efx_tx_queue *tx_queue, - struct efx_tx_buffer *buffer) -{ - if (buffer->unmap_len) { - struct pci_dev *pci_dev = tx_queue->efx->pci_dev; - if (buffer->unmap_single) - pci_unmap_single(pci_dev, buffer->unmap_addr, - buffer->unmap_len, PCI_DMA_TODEVICE); - else - pci_unmap_page(pci_dev, buffer->unmap_addr, - buffer->unmap_len, PCI_DMA_TODEVICE); - buffer->unmap_len = 0; - buffer->unmap_single = 0; - } - - if (buffer->skb) { - dev_kfree_skb_any((struct sk_buff *) buffer->skb); - buffer->skb = NULL; - EFX_TRACE(tx_queue->efx, "TX queue %d transmission id %x " - "complete\n", tx_queue->queue, read_ptr); - } -} - -/** - * struct efx_tso_header - a DMA mapped buffer for packet headers - * @next: Linked list of free ones. - * The list is protected by the TX queue lock. - * @dma_unmap_len: Length to unmap for an oversize buffer, or 0. - * @dma_addr: The DMA address of the header below. - * - * This controls the memory used for a TSO header. Use TSOH_DATA() - * to find the packet header data. Use TSOH_SIZE() to calculate the - * total size required for a given packet header length. TSO headers - * in the free list are exactly %TSOH_STD_SIZE bytes in size. - */ -struct efx_tso_header { - union { - struct efx_tso_header *next; - size_t unmap_len; - }; - dma_addr_t dma_addr; -}; - -static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, - const struct sk_buff *skb); -static void efx_fini_tso(struct efx_tx_queue *tx_queue); -static void efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, - struct efx_tso_header *tsoh); - -static inline void efx_tsoh_free(struct efx_tx_queue *tx_queue, - struct efx_tx_buffer *buffer) -{ - if (buffer->tsoh) { - if (likely(!buffer->tsoh->unmap_len)) { - buffer->tsoh->next = tx_queue->tso_headers_free; - tx_queue->tso_headers_free = buffer->tsoh; - } else { - efx_tsoh_heap_free(tx_queue, buffer->tsoh); - } - buffer->tsoh = NULL; - } -} - - -/* - * Add a socket buffer to a TX queue - * - * This maps all fragments of a socket buffer for DMA and adds them to - * the TX queue. The queue's insert pointer will be incremented by - * the number of fragments in the socket buffer. - * - * If any DMA mapping fails, any mapped fragments will be unmapped, - * the queue's insert pointer will be restored to its original value. - * - * Returns NETDEV_TX_OK or NETDEV_TX_BUSY - * You must hold netif_tx_lock() to call this function. - */ -static inline int efx_enqueue_skb(struct efx_tx_queue *tx_queue, - const struct sk_buff *skb) -{ - struct efx_nic *efx = tx_queue->efx; - struct pci_dev *pci_dev = efx->pci_dev; - struct efx_tx_buffer *buffer; - skb_frag_t *fragment; - struct page *page; - int page_offset; - unsigned int len, unmap_len = 0, fill_level, insert_ptr, misalign; - dma_addr_t dma_addr, unmap_addr = 0; - unsigned int dma_len; - unsigned unmap_single; - int q_space, i = 0; - int rc = NETDEV_TX_OK; - - EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); - - if (skb_shinfo((struct sk_buff *)skb)->gso_size) - return efx_enqueue_skb_tso(tx_queue, skb); - - /* Get size of the initial fragment */ - len = skb_headlen(skb); - - fill_level = tx_queue->insert_count - tx_queue->old_read_count; - q_space = efx->type->txd_ring_mask - 1 - fill_level; - - /* Map for DMA. Use pci_map_single rather than pci_map_page - * since this is more efficient on machines with sparse - * memory. - */ - unmap_single = 1; - dma_addr = pci_map_single(pci_dev, skb->data, len, PCI_DMA_TODEVICE); - - /* Process all fragments */ - while (1) { - if (unlikely(pci_dma_mapping_error(pci_dev, dma_addr))) - goto pci_err; - - /* Store fields for marking in the per-fragment final - * descriptor */ - unmap_len = len; - unmap_addr = dma_addr; - - /* Add to TX queue, splitting across DMA boundaries */ - do { - if (unlikely(q_space-- <= 0)) { - /* It might be that completions have - * happened since the xmit path last - * checked. Update the xmit path's - * copy of read_count. - */ - ++tx_queue->stopped; - /* This memory barrier protects the - * change of stopped from the access - * of read_count. */ - smp_mb(); - tx_queue->old_read_count = - *(volatile unsigned *) - &tx_queue->read_count; - fill_level = (tx_queue->insert_count - - tx_queue->old_read_count); - q_space = (efx->type->txd_ring_mask - 1 - - fill_level); - if (unlikely(q_space-- <= 0)) - goto stop; - smp_mb(); - --tx_queue->stopped; - } - - insert_ptr = (tx_queue->insert_count & - efx->type->txd_ring_mask); - buffer = &tx_queue->buffer[insert_ptr]; - efx_tsoh_free(tx_queue, buffer); - EFX_BUG_ON_PARANOID(buffer->tsoh); - EFX_BUG_ON_PARANOID(buffer->skb); - EFX_BUG_ON_PARANOID(buffer->len); - EFX_BUG_ON_PARANOID(buffer->continuation != 1); - EFX_BUG_ON_PARANOID(buffer->unmap_len); - - dma_len = (((~dma_addr) & efx->type->tx_dma_mask) + 1); - if (likely(dma_len > len)) - dma_len = len; - - misalign = (unsigned)dma_addr & efx->type->bug5391_mask; - if (misalign && dma_len + misalign > 512) - dma_len = 512 - misalign; - - /* Fill out per descriptor fields */ - buffer->len = dma_len; - buffer->dma_addr = dma_addr; - len -= dma_len; - dma_addr += dma_len; - ++tx_queue->insert_count; - } while (len); - - /* Transfer ownership of the unmapping to the final buffer */ - buffer->unmap_addr = unmap_addr; - buffer->unmap_single = unmap_single; - buffer->unmap_len = unmap_len; - unmap_len = 0; - - /* Get address and size of next fragment */ - if (i >= skb_shinfo(skb)->nr_frags) - break; - fragment = &skb_shinfo(skb)->frags[i]; - len = fragment->size; - page = fragment->page; - page_offset = fragment->page_offset; - i++; - /* Map for DMA */ - unmap_single = 0; - dma_addr = pci_map_page(pci_dev, page, page_offset, len, - PCI_DMA_TODEVICE); - } - - /* Transfer ownership of the skb to the final buffer */ - buffer->skb = skb; - buffer->continuation = 0; - - /* Pass off to hardware */ - falcon_push_buffers(tx_queue); - - return NETDEV_TX_OK; - - pci_err: - EFX_ERR_RL(efx, " TX queue %d could not map skb with %d bytes %d " - "fragments for DMA\n", tx_queue->queue, skb->len, - skb_shinfo(skb)->nr_frags + 1); - - /* Mark the packet as transmitted, and free the SKB ourselves */ - dev_kfree_skb_any((struct sk_buff *)skb); - goto unwind; - - stop: - rc = NETDEV_TX_BUSY; - - if (tx_queue->stopped == 1) - efx_stop_queue(efx); - - unwind: - /* Work backwards until we hit the original insert pointer value */ - while (tx_queue->insert_count != tx_queue->write_count) { - --tx_queue->insert_count; - insert_ptr = tx_queue->insert_count & efx->type->txd_ring_mask; - buffer = &tx_queue->buffer[insert_ptr]; - efx_dequeue_buffer(tx_queue, buffer); - buffer->len = 0; - } - - /* Free the fragment we were mid-way through pushing */ - if (unmap_len) - pci_unmap_page(pci_dev, unmap_addr, unmap_len, - PCI_DMA_TODEVICE); - - return rc; -} - -/* Remove packets from the TX queue - * - * This removes packets from the TX queue, up to and including the - * specified index. - */ -static inline void efx_dequeue_buffers(struct efx_tx_queue *tx_queue, - unsigned int index) -{ - struct efx_nic *efx = tx_queue->efx; - unsigned int stop_index, read_ptr; - unsigned int mask = tx_queue->efx->type->txd_ring_mask; - - stop_index = (index + 1) & mask; - read_ptr = tx_queue->read_count & mask; - - while (read_ptr != stop_index) { - struct efx_tx_buffer *buffer = &tx_queue->buffer[read_ptr]; - if (unlikely(buffer->len == 0)) { - EFX_ERR(tx_queue->efx, "TX queue %d spurious TX " - "completion id %x\n", tx_queue->queue, - read_ptr); - efx_schedule_reset(efx, RESET_TYPE_TX_SKIP); - return; - } - - efx_dequeue_buffer(tx_queue, buffer); - buffer->continuation = 1; - buffer->len = 0; - - ++tx_queue->read_count; - read_ptr = tx_queue->read_count & mask; - } -} - -/* Initiate a packet transmission on the specified TX queue. - * Note that returning anything other than NETDEV_TX_OK will cause the - * OS to free the skb. - * - * This function is split out from efx_hard_start_xmit to allow the - * loopback test to direct packets via specific TX queues. It is - * therefore a non-static inline, so as not to penalise performance - * for non-loopback transmissions. - * - * Context: netif_tx_lock held - */ -inline int efx_xmit(struct efx_nic *efx, - struct efx_tx_queue *tx_queue, struct sk_buff *skb) -{ - int rc; - - /* Map fragments for DMA and add to TX queue */ - rc = efx_enqueue_skb(tx_queue, skb); - if (unlikely(rc != NETDEV_TX_OK)) - goto out; - - /* Update last TX timer */ - efx->net_dev->trans_start = jiffies; - - out: - return rc; -} - -/* Initiate a packet transmission. We use one channel per CPU - * (sharing when we have more CPUs than channels). On Falcon, the TX - * completion events will be directed back to the CPU that transmitted - * the packet, which should be cache-efficient. - * - * Context: non-blocking. - * Note that returning anything other than NETDEV_TX_OK will cause the - * OS to free the skb. - */ -int efx_hard_start_xmit(struct sk_buff *skb, struct net_device *net_dev) -{ - struct efx_nic *efx = net_dev->priv; - return efx_xmit(efx, &efx->tx_queue[0], skb); -} - -void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index) -{ - unsigned fill_level; - struct efx_nic *efx = tx_queue->efx; - - EFX_BUG_ON_PARANOID(index > efx->type->txd_ring_mask); - - efx_dequeue_buffers(tx_queue, index); - - /* See if we need to restart the netif queue. This barrier - * separates the update of read_count from the test of - * stopped. */ - smp_mb(); - if (unlikely(tx_queue->stopped)) { - fill_level = tx_queue->insert_count - tx_queue->read_count; - if (fill_level < EFX_NETDEV_TX_THRESHOLD(tx_queue)) { - EFX_BUG_ON_PARANOID(!efx_dev_registered(efx)); - - /* Do this under netif_tx_lock(), to avoid racing - * with efx_xmit(). */ - netif_tx_lock(efx->net_dev); - if (tx_queue->stopped) { - tx_queue->stopped = 0; - efx_wake_queue(efx); - } - netif_tx_unlock(efx->net_dev); - } - } -} - -int efx_probe_tx_queue(struct efx_tx_queue *tx_queue) -{ - struct efx_nic *efx = tx_queue->efx; - unsigned int txq_size; - int i, rc; - - EFX_LOG(efx, "creating TX queue %d\n", tx_queue->queue); - - /* Allocate software ring */ - txq_size = (efx->type->txd_ring_mask + 1) * sizeof(*tx_queue->buffer); - tx_queue->buffer = kzalloc(txq_size, GFP_KERNEL); - if (!tx_queue->buffer) { - rc = -ENOMEM; - goto fail1; - } - for (i = 0; i <= efx->type->txd_ring_mask; ++i) - tx_queue->buffer[i].continuation = 1; - - /* Allocate hardware ring */ - rc = falcon_probe_tx(tx_queue); - if (rc) - goto fail2; - - return 0; - - fail2: - kfree(tx_queue->buffer); - tx_queue->buffer = NULL; - fail1: - tx_queue->used = 0; - - return rc; -} - -int efx_init_tx_queue(struct efx_tx_queue *tx_queue) -{ - EFX_LOG(tx_queue->efx, "initialising TX queue %d\n", tx_queue->queue); - - tx_queue->insert_count = 0; - tx_queue->write_count = 0; - tx_queue->read_count = 0; - tx_queue->old_read_count = 0; - BUG_ON(tx_queue->stopped); - - /* Set up TX descriptor ring */ - return falcon_init_tx(tx_queue); -} - -void efx_release_tx_buffers(struct efx_tx_queue *tx_queue) -{ - struct efx_tx_buffer *buffer; - - if (!tx_queue->buffer) - return; - - /* Free any buffers left in the ring */ - while (tx_queue->read_count != tx_queue->write_count) { - buffer = &tx_queue->buffer[tx_queue->read_count & - tx_queue->efx->type->txd_ring_mask]; - efx_dequeue_buffer(tx_queue, buffer); - buffer->continuation = 1; - buffer->len = 0; - - ++tx_queue->read_count; - } -} - -void efx_fini_tx_queue(struct efx_tx_queue *tx_queue) -{ - EFX_LOG(tx_queue->efx, "shutting down TX queue %d\n", tx_queue->queue); - - /* Flush TX queue, remove descriptor ring */ - falcon_fini_tx(tx_queue); - - efx_release_tx_buffers(tx_queue); - - /* Free up TSO header cache */ - efx_fini_tso(tx_queue); - - /* Release queue's stop on port, if any */ - if (tx_queue->stopped) { - tx_queue->stopped = 0; - efx_wake_queue(tx_queue->efx); - } -} - -void efx_remove_tx_queue(struct efx_tx_queue *tx_queue) -{ - EFX_LOG(tx_queue->efx, "destroying TX queue %d\n", tx_queue->queue); - falcon_remove_tx(tx_queue); - - kfree(tx_queue->buffer); - tx_queue->buffer = NULL; - tx_queue->used = 0; -} - - -/* Efx TCP segmentation acceleration. - * - * Why? Because by doing it here in the driver we can go significantly - * faster than the GSO. - * - * Requires TX checksum offload support. - */ - -/* Number of bytes inserted at the start of a TSO header buffer, - * similar to NET_IP_ALIGN. - */ -#if defined(__i386__) || defined(__x86_64__) -#define TSOH_OFFSET 0 -#else -#define TSOH_OFFSET NET_IP_ALIGN -#endif - -#define TSOH_BUFFER(tsoh) ((u8 *)(tsoh + 1) + TSOH_OFFSET) - -/* Total size of struct efx_tso_header, buffer and padding */ -#define TSOH_SIZE(hdr_len) \ - (sizeof(struct efx_tso_header) + TSOH_OFFSET + hdr_len) - -/* Size of blocks on free list. Larger blocks must be allocated from - * the heap. - */ -#define TSOH_STD_SIZE 128 - -#define PTR_DIFF(p1, p2) ((u8 *)(p1) - (u8 *)(p2)) -#define ETH_HDR_LEN(skb) (skb_network_header(skb) - (skb)->data) -#define SKB_TCP_OFF(skb) PTR_DIFF(tcp_hdr(skb), (skb)->data) -#define SKB_IPV4_OFF(skb) PTR_DIFF(ip_hdr(skb), (skb)->data) - -/** - * struct tso_state - TSO state for an SKB - * @remaining_len: Bytes of data we've yet to segment - * @seqnum: Current sequence number - * @packet_space: Remaining space in current packet - * @ifc: Input fragment cursor. - * Where we are in the current fragment of the incoming SKB. These - * values get updated in place when we split a fragment over - * multiple packets. - * @p: Parameters. - * These values are set once at the start of the TSO send and do - * not get changed as the routine progresses. - * - * The state used during segmentation. It is put into this data structure - * just to make it easy to pass into inline functions. - */ -struct tso_state { - unsigned remaining_len; - unsigned seqnum; - unsigned packet_space; - - struct { - /* DMA address of current position */ - dma_addr_t dma_addr; - /* Remaining length */ - unsigned int len; - /* DMA address and length of the whole fragment */ - unsigned int unmap_len; - dma_addr_t unmap_addr; - struct page *page; - unsigned page_off; - } ifc; - - struct { - /* The number of bytes of header */ - unsigned int header_length; - - /* The number of bytes to put in each outgoing segment. */ - int full_packet_size; - - /* Current IPv4 ID, host endian. */ - unsigned ipv4_id; - } p; -}; - - -/* - * Verify that our various assumptions about sk_buffs and the conditions - * under which TSO will be attempted hold true. - */ -static inline void efx_tso_check_safe(const struct sk_buff *skb) -{ - EFX_BUG_ON_PARANOID(skb->protocol != htons(ETH_P_IP)); - EFX_BUG_ON_PARANOID(((struct ethhdr *)skb->data)->h_proto != - skb->protocol); - EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP); - EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb), skb->data) - + (tcp_hdr(skb)->doff << 2u)) > - skb_headlen(skb)); -} - - -/* - * Allocate a page worth of efx_tso_header structures, and string them - * into the tx_queue->tso_headers_free linked list. Return 0 or -ENOMEM. - */ -static int efx_tsoh_block_alloc(struct efx_tx_queue *tx_queue) -{ - - struct pci_dev *pci_dev = tx_queue->efx->pci_dev; - struct efx_tso_header *tsoh; - dma_addr_t dma_addr; - u8 *base_kva, *kva; - - base_kva = pci_alloc_consistent(pci_dev, PAGE_SIZE, &dma_addr); - if (base_kva == NULL) { - EFX_ERR(tx_queue->efx, "Unable to allocate page for TSO" - " headers\n"); - return -ENOMEM; - } - - /* pci_alloc_consistent() allocates pages. */ - EFX_BUG_ON_PARANOID(dma_addr & (PAGE_SIZE - 1u)); - - for (kva = base_kva; kva < base_kva + PAGE_SIZE; kva += TSOH_STD_SIZE) { - tsoh = (struct efx_tso_header *)kva; - tsoh->dma_addr = dma_addr + (TSOH_BUFFER(tsoh) - base_kva); - tsoh->next = tx_queue->tso_headers_free; - tx_queue->tso_headers_free = tsoh; - } - - return 0; -} - - -/* Free up a TSO header, and all others in the same page. */ -static void efx_tsoh_block_free(struct efx_tx_queue *tx_queue, - struct efx_tso_header *tsoh, - struct pci_dev *pci_dev) -{ - struct efx_tso_header **p; - unsigned long base_kva; - dma_addr_t base_dma; - - base_kva = (unsigned long)tsoh & PAGE_MASK; - base_dma = tsoh->dma_addr & PAGE_MASK; - - p = &tx_queue->tso_headers_free; - while (*p != NULL) { - if (((unsigned long)*p & PAGE_MASK) == base_kva) - *p = (*p)->next; - else - p = &(*p)->next; - } - - pci_free_consistent(pci_dev, PAGE_SIZE, (void *)base_kva, base_dma); -} - -static struct efx_tso_header * -efx_tsoh_heap_alloc(struct efx_tx_queue *tx_queue, size_t header_len) -{ - struct efx_tso_header *tsoh; - - tsoh = kmalloc(TSOH_SIZE(header_len), GFP_ATOMIC | GFP_DMA); - if (unlikely(!tsoh)) - return NULL; - - tsoh->dma_addr = pci_map_single(tx_queue->efx->pci_dev, - TSOH_BUFFER(tsoh), header_len, - PCI_DMA_TODEVICE); - if (unlikely(pci_dma_mapping_error(tx_queue->efx->pci_dev, - tsoh->dma_addr))) { - kfree(tsoh); - return NULL; - } - - tsoh->unmap_len = header_len; - return tsoh; -} - -static void -efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, struct efx_tso_header *tsoh) -{ - pci_unmap_single(tx_queue->efx->pci_dev, - tsoh->dma_addr, tsoh->unmap_len, - PCI_DMA_TODEVICE); - kfree(tsoh); -} - -/** - * efx_tx_queue_insert - push descriptors onto the TX queue - * @tx_queue: Efx TX queue - * @dma_addr: DMA address of fragment - * @len: Length of fragment - * @skb: Only non-null for end of last segment - * @end_of_packet: True if last fragment in a packet - * @unmap_addr: DMA address of fragment for unmapping - * @unmap_len: Only set this in last segment of a fragment - * - * Push descriptors onto the TX queue. Return 0 on success or 1 if - * @tx_queue full. - */ -static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue, - dma_addr_t dma_addr, unsigned len, - const struct sk_buff *skb, int end_of_packet, - dma_addr_t unmap_addr, unsigned unmap_len) -{ - struct efx_tx_buffer *buffer; - struct efx_nic *efx = tx_queue->efx; - unsigned dma_len, fill_level, insert_ptr, misalign; - int q_space; - - EFX_BUG_ON_PARANOID(len <= 0); - - fill_level = tx_queue->insert_count - tx_queue->old_read_count; - /* -1 as there is no way to represent all descriptors used */ - q_space = efx->type->txd_ring_mask - 1 - fill_level; - - while (1) { - if (unlikely(q_space-- <= 0)) { - /* It might be that completions have happened - * since the xmit path last checked. Update - * the xmit path's copy of read_count. - */ - ++tx_queue->stopped; - /* This memory barrier protects the change of - * stopped from the access of read_count. */ - smp_mb(); - tx_queue->old_read_count = - *(volatile unsigned *)&tx_queue->read_count; - fill_level = (tx_queue->insert_count - - tx_queue->old_read_count); - q_space = efx->type->txd_ring_mask - 1 - fill_level; - if (unlikely(q_space-- <= 0)) - return 1; - smp_mb(); - --tx_queue->stopped; - } - - insert_ptr = tx_queue->insert_count & efx->type->txd_ring_mask; - buffer = &tx_queue->buffer[insert_ptr]; - ++tx_queue->insert_count; - - EFX_BUG_ON_PARANOID(tx_queue->insert_count - - tx_queue->read_count > - efx->type->txd_ring_mask); - - efx_tsoh_free(tx_queue, buffer); - EFX_BUG_ON_PARANOID(buffer->len); - EFX_BUG_ON_PARANOID(buffer->unmap_len); - EFX_BUG_ON_PARANOID(buffer->skb); - EFX_BUG_ON_PARANOID(buffer->continuation != 1); - EFX_BUG_ON_PARANOID(buffer->tsoh); - - buffer->dma_addr = dma_addr; - - /* Ensure we do not cross a boundary unsupported by H/W */ - dma_len = (~dma_addr & efx->type->tx_dma_mask) + 1; - - misalign = (unsigned)dma_addr & efx->type->bug5391_mask; - if (misalign && dma_len + misalign > 512) - dma_len = 512 - misalign; - - /* If there is enough space to send then do so */ - if (dma_len >= len) - break; - - buffer->len = dma_len; /* Don't set the other members */ - dma_addr += dma_len; - len -= dma_len; - } - - EFX_BUG_ON_PARANOID(!len); - buffer->len = len; - buffer->skb = skb; - buffer->continuation = !end_of_packet; - buffer->unmap_addr = unmap_addr; - buffer->unmap_len = unmap_len; - return 0; -} - - -/* - * Put a TSO header into the TX queue. - * - * This is special-cased because we know that it is small enough to fit in - * a single fragment, and we know it doesn't cross a page boundary. It - * also allows us to not worry about end-of-packet etc. - */ -static inline void efx_tso_put_header(struct efx_tx_queue *tx_queue, - struct efx_tso_header *tsoh, unsigned len) -{ - struct efx_tx_buffer *buffer; - - buffer = &tx_queue->buffer[tx_queue->insert_count & - tx_queue->efx->type->txd_ring_mask]; - efx_tsoh_free(tx_queue, buffer); - EFX_BUG_ON_PARANOID(buffer->len); - EFX_BUG_ON_PARANOID(buffer->unmap_len); - EFX_BUG_ON_PARANOID(buffer->skb); - EFX_BUG_ON_PARANOID(buffer->continuation != 1); - EFX_BUG_ON_PARANOID(buffer->tsoh); - buffer->len = len; - buffer->dma_addr = tsoh->dma_addr; - buffer->tsoh = tsoh; - - ++tx_queue->insert_count; -} - - -/* Remove descriptors put into a tx_queue. */ -static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue) -{ - struct efx_tx_buffer *buffer; - - /* Work backwards until we hit the original insert pointer value */ - while (tx_queue->insert_count != tx_queue->write_count) { - --tx_queue->insert_count; - buffer = &tx_queue->buffer[tx_queue->insert_count & - tx_queue->efx->type->txd_ring_mask]; - efx_tsoh_free(tx_queue, buffer); - EFX_BUG_ON_PARANOID(buffer->skb); - buffer->len = 0; - buffer->continuation = 1; - if (buffer->unmap_len) { - pci_unmap_page(tx_queue->efx->pci_dev, - buffer->unmap_addr, - buffer->unmap_len, PCI_DMA_TODEVICE); - buffer->unmap_len = 0; - } - } -} - - -/* Parse the SKB header and initialise state. */ -static inline void tso_start(struct tso_state *st, const struct sk_buff *skb) -{ - /* All ethernet/IP/TCP headers combined size is TCP header size - * plus offset of TCP header relative to start of packet. - */ - st->p.header_length = ((tcp_hdr(skb)->doff << 2u) - + PTR_DIFF(tcp_hdr(skb), skb->data)); - st->p.full_packet_size = (st->p.header_length - + skb_shinfo(skb)->gso_size); - - st->p.ipv4_id = ntohs(ip_hdr(skb)->id); - st->seqnum = ntohl(tcp_hdr(skb)->seq); - - EFX_BUG_ON_PARANOID(tcp_hdr(skb)->urg); - EFX_BUG_ON_PARANOID(tcp_hdr(skb)->syn); - EFX_BUG_ON_PARANOID(tcp_hdr(skb)->rst); - - st->packet_space = st->p.full_packet_size; - st->remaining_len = skb->len - st->p.header_length; -} - - -/** - * tso_get_fragment - record fragment details and map for DMA - * @st: TSO state - * @efx: Efx NIC - * @data: Pointer to fragment data - * @len: Length of fragment - * - * Record fragment details and map for DMA. Return 0 on success, or - * -%ENOMEM if DMA mapping fails. - */ -static inline int tso_get_fragment(struct tso_state *st, struct efx_nic *efx, - int len, struct page *page, int page_off) -{ - - st->ifc.unmap_addr = pci_map_page(efx->pci_dev, page, page_off, - len, PCI_DMA_TODEVICE); - if (likely(!pci_dma_mapping_error(efx->pci_dev, st->ifc.unmap_addr))) { - st->ifc.unmap_len = len; - st->ifc.len = len; - st->ifc.dma_addr = st->ifc.unmap_addr; - st->ifc.page = page; - st->ifc.page_off = page_off; - return 0; - } - return -ENOMEM; -} - - -/** - * tso_fill_packet_with_fragment - form descriptors for the current fragment - * @tx_queue: Efx TX queue - * @skb: Socket buffer - * @st: TSO state - * - * Form descriptors for the current fragment, until we reach the end - * of fragment or end-of-packet. Return 0 on success, 1 if not enough - * space in @tx_queue. - */ -static inline int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue, - const struct sk_buff *skb, - struct tso_state *st) -{ - - int n, end_of_packet, rc; - - if (st->ifc.len == 0) - return 0; - if (st->packet_space == 0) - return 0; - - EFX_BUG_ON_PARANOID(st->ifc.len <= 0); - EFX_BUG_ON_PARANOID(st->packet_space <= 0); - - n = min(st->ifc.len, st->packet_space); - - st->packet_space -= n; - st->remaining_len -= n; - st->ifc.len -= n; - st->ifc.page_off += n; - end_of_packet = st->remaining_len == 0 || st->packet_space == 0; - - rc = efx_tx_queue_insert(tx_queue, st->ifc.dma_addr, n, - st->remaining_len ? NULL : skb, - end_of_packet, st->ifc.unmap_addr, - st->ifc.len ? 0 : st->ifc.unmap_len); - - st->ifc.dma_addr += n; - - return rc; -} - - -/** - * tso_start_new_packet - generate a new header and prepare for the new packet - * @tx_queue: Efx TX queue - * @skb: Socket buffer - * @st: TSO state - * - * Generate a new header and prepare for the new packet. Return 0 on - * success, or -1 if failed to alloc header. - */ -static inline int tso_start_new_packet(struct efx_tx_queue *tx_queue, - const struct sk_buff *skb, - struct tso_state *st) -{ - struct efx_tso_header *tsoh; - struct iphdr *tsoh_iph; - struct tcphdr *tsoh_th; - unsigned ip_length; - u8 *header; - - /* Allocate a DMA-mapped header buffer. */ - if (likely(TSOH_SIZE(st->p.header_length) <= TSOH_STD_SIZE)) { - if (tx_queue->tso_headers_free == NULL) { - if (efx_tsoh_block_alloc(tx_queue)) - return -1; - } - EFX_BUG_ON_PARANOID(!tx_queue->tso_headers_free); - tsoh = tx_queue->tso_headers_free; - tx_queue->tso_headers_free = tsoh->next; - tsoh->unmap_len = 0; - } else { - tx_queue->tso_long_headers++; - tsoh = efx_tsoh_heap_alloc(tx_queue, st->p.header_length); - if (unlikely(!tsoh)) - return -1; - } - - header = TSOH_BUFFER(tsoh); - tsoh_th = (struct tcphdr *)(header + SKB_TCP_OFF(skb)); - tsoh_iph = (struct iphdr *)(header + SKB_IPV4_OFF(skb)); - - /* Copy and update the headers. */ - memcpy(header, skb->data, st->p.header_length); - - tsoh_th->seq = htonl(st->seqnum); - st->seqnum += skb_shinfo(skb)->gso_size; - if (st->remaining_len > skb_shinfo(skb)->gso_size) { - /* This packet will not finish the TSO burst. */ - ip_length = st->p.full_packet_size - ETH_HDR_LEN(skb); - tsoh_th->fin = 0; - tsoh_th->psh = 0; - } else { - /* This packet will be the last in the TSO burst. */ - ip_length = (st->p.header_length - ETH_HDR_LEN(skb) - + st->remaining_len); - tsoh_th->fin = tcp_hdr(skb)->fin; - tsoh_th->psh = tcp_hdr(skb)->psh; - } - tsoh_iph->tot_len = htons(ip_length); - - /* Linux leaves suitable gaps in the IP ID space for us to fill. */ - tsoh_iph->id = htons(st->p.ipv4_id); - st->p.ipv4_id++; - - st->packet_space = skb_shinfo(skb)->gso_size; - ++tx_queue->tso_packets; - - /* Form a descriptor for this header. */ - efx_tso_put_header(tx_queue, tsoh, st->p.header_length); - - return 0; -} - - -/** - * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer - * @tx_queue: Efx TX queue - * @skb: Socket buffer - * - * Context: You must hold netif_tx_lock() to call this function. - * - * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if - * @skb was not enqueued. In all cases @skb is consumed. Return - * %NETDEV_TX_OK or %NETDEV_TX_BUSY. - */ -static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, - const struct sk_buff *skb) -{ - int frag_i, rc, rc2 = NETDEV_TX_OK; - struct tso_state state; - skb_frag_t *f; - - /* Verify TSO is safe - these checks should never fail. */ - efx_tso_check_safe(skb); - - EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); - - tso_start(&state, skb); - - /* Assume that skb header area contains exactly the headers, and - * all payload is in the frag list. - */ - if (skb_headlen(skb) == state.p.header_length) { - /* Grab the first payload fragment. */ - EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1); - frag_i = 0; - f = &skb_shinfo(skb)->frags[frag_i]; - rc = tso_get_fragment(&state, tx_queue->efx, - f->size, f->page, f->page_offset); - if (rc) - goto mem_err; - } else { - /* It may look like this code fragment assumes that the - * skb->data portion does not cross a page boundary, but - * that is not the case. It is guaranteed to be direct - * mapped memory, and therefore is physically contiguous, - * and so DMA will work fine. kmap_atomic() on this region - * will just return the direct mapping, so that will work - * too. - */ - int page_off = (unsigned long)skb->data & (PAGE_SIZE - 1); - int hl = state.p.header_length; - rc = tso_get_fragment(&state, tx_queue->efx, - skb_headlen(skb) - hl, - virt_to_page(skb->data), page_off + hl); - if (rc) - goto mem_err; - frag_i = -1; - } - - if (tso_start_new_packet(tx_queue, skb, &state) < 0) - goto mem_err; - - while (1) { - rc = tso_fill_packet_with_fragment(tx_queue, skb, &state); - if (unlikely(rc)) - goto stop; - - /* Move onto the next fragment? */ - if (state.ifc.len == 0) { - if (++frag_i >= skb_shinfo(skb)->nr_frags) - /* End of payload reached. */ - break; - f = &skb_shinfo(skb)->frags[frag_i]; - rc = tso_get_fragment(&state, tx_queue->efx, - f->size, f->page, f->page_offset); - if (rc) - goto mem_err; - } - - /* Start at new packet? */ - if (state.packet_space == 0 && - tso_start_new_packet(tx_queue, skb, &state) < 0) - goto mem_err; - } - - /* Pass off to hardware */ - falcon_push_buffers(tx_queue); - - tx_queue->tso_bursts++; - return NETDEV_TX_OK; - - mem_err: - EFX_ERR(tx_queue->efx, "Out of memory for TSO headers, or PCI mapping" - " error\n"); - dev_kfree_skb_any((struct sk_buff *)skb); - goto unwind; - - stop: - rc2 = NETDEV_TX_BUSY; - - /* Stop the queue if it wasn't stopped before. */ - if (tx_queue->stopped == 1) - efx_stop_queue(tx_queue->efx); - - unwind: - efx_enqueue_unwind(tx_queue); - return rc2; -} - - -/* - * Free up all TSO datastructures associated with tx_queue. This - * routine should be called only once the tx_queue is both empty and - * will no longer be used. - */ -static void efx_fini_tso(struct efx_tx_queue *tx_queue) -{ - unsigned i; - - if (tx_queue->buffer) { - for (i = 0; i <= tx_queue->efx->type->txd_ring_mask; ++i) - efx_tsoh_free(tx_queue, &tx_queue->buffer[i]); - } - - while (tx_queue->tso_headers_free != NULL) - efx_tsoh_block_free(tx_queue, tx_queue->tso_headers_free, - tx_queue->efx->pci_dev); -} |