/* Efx legacy TCP segmentation acceleration.
*
- * Why? Because by doing it here in the driver we can go significantly
- * faster than the GSO.
+ * Utilises firmware support to go faster than GSO (but not as fast as TSOv2).
*
* Requires TX checksum offload support.
*/
* @in_len: Remaining length in current SKB fragment
* @unmap_len: Length of SKB fragment
* @unmap_addr: DMA address of SKB fragment
- * @dma_flags: TX buffer flags for DMA mapping - %EFX_TX_BUF_MAP_SINGLE or 0
* @protocol: Network protocol (after any VLAN header)
* @ip_off: Offset of IP header
* @tcp_off: Offset of TCP header
* @header_len: Number of bytes of header
* @ip_base_len: IPv4 tot_len or IPv6 payload_len, before TCP payload
- * @header_dma_addr: Header DMA address, when using option descriptors
- * @header_unmap_len: Header DMA mapped length, or 0 if not using option
- * descriptors
+ * @header_dma_addr: Header DMA address
+ * @header_unmap_len: Header DMA mapped length
*
* The state used during segmentation. It is put into this data structure
* just to make it easy to pass into inline functions.
unsigned int in_len;
unsigned int unmap_len;
dma_addr_t unmap_addr;
- unsigned short dma_flags;
__be16 protocol;
unsigned int ip_off;
return protocol;
}
-static u8 *efx_tsoh_get_buffer(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer, unsigned int len)
-{
- u8 *result;
-
- EFX_BUG_ON_PARANOID(buffer->len);
- EFX_BUG_ON_PARANOID(buffer->flags);
- EFX_BUG_ON_PARANOID(buffer->unmap_len);
-
- result = efx_tx_get_copy_buffer_limited(tx_queue, buffer, len);
-
- if (result) {
- buffer->flags = EFX_TX_BUF_CONT;
- } else {
- buffer->heap_buf = kmalloc(NET_IP_ALIGN + len, GFP_ATOMIC);
- if (unlikely(!buffer->heap_buf))
- return NULL;
- tx_queue->tso_long_headers++;
- result = (u8 *)buffer->heap_buf + NET_IP_ALIGN;
- buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_HEAP;
- }
-
- buffer->len = len;
-
- return result;
-}
-
-/*
- * 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 int efx_tso_put_header(struct efx_tx_queue *tx_queue,
- struct efx_tx_buffer *buffer, u8 *header)
-{
- if (unlikely(buffer->flags & EFX_TX_BUF_HEAP)) {
- buffer->dma_addr = dma_map_single(&tx_queue->efx->pci_dev->dev,
- header, buffer->len,
- DMA_TO_DEVICE);
- if (unlikely(dma_mapping_error(&tx_queue->efx->pci_dev->dev,
- buffer->dma_addr))) {
- kfree(buffer->heap_buf);
- buffer->len = 0;
- buffer->flags = 0;
- return -ENOMEM;
- }
- buffer->unmap_len = buffer->len;
- buffer->dma_offset = 0;
- buffer->flags |= EFX_TX_BUF_MAP_SINGLE;
- }
-
- ++tx_queue->insert_count;
- return 0;
-}
-
/* Parse the SKB header and initialise state. */
static int tso_start(struct tso_state *st, struct efx_nic *efx,
{
struct device *dma_dev = &efx->pci_dev->dev;
unsigned int header_len, in_len;
- bool use_opt_desc = false;
dma_addr_t dma_addr;
- if (tx_queue->tso_version == 1)
- use_opt_desc = true;
-
st->ip_off = skb_network_header(skb) - skb->data;
st->tcp_off = skb_transport_header(skb) - skb->data;
header_len = st->tcp_off + (tcp_hdr(skb)->doff << 2u);
st->out_len = skb->len - header_len;
- if (!use_opt_desc) {
- st->header_unmap_len = 0;
-
- if (likely(in_len == 0)) {
- st->dma_flags = 0;
- st->unmap_len = 0;
- return 0;
- }
-
- dma_addr = dma_map_single(dma_dev, skb->data + header_len,
- in_len, DMA_TO_DEVICE);
- st->dma_flags = EFX_TX_BUF_MAP_SINGLE;
- st->dma_addr = dma_addr;
- st->unmap_addr = dma_addr;
- st->unmap_len = in_len;
- } else {
- dma_addr = dma_map_single(dma_dev, skb->data,
- skb_headlen(skb), DMA_TO_DEVICE);
- st->header_dma_addr = dma_addr;
- st->header_unmap_len = skb_headlen(skb);
- st->dma_flags = 0;
- st->dma_addr = dma_addr + header_len;
- st->unmap_len = 0;
- }
+ dma_addr = dma_map_single(dma_dev, skb->data,
+ skb_headlen(skb), DMA_TO_DEVICE);
+ st->header_dma_addr = dma_addr;
+ st->header_unmap_len = skb_headlen(skb);
+ st->dma_addr = dma_addr + header_len;
+ st->unmap_len = 0;
return unlikely(dma_mapping_error(dma_dev, dma_addr)) ? -ENOMEM : 0;
}
st->unmap_addr = skb_frag_dma_map(&efx->pci_dev->dev, frag, 0,
skb_frag_size(frag), DMA_TO_DEVICE);
if (likely(!dma_mapping_error(&efx->pci_dev->dev, st->unmap_addr))) {
- st->dma_flags = 0;
st->unmap_len = skb_frag_size(frag);
st->in_len = skb_frag_size(frag);
st->dma_addr = st->unmap_addr;
/* Transfer ownership of the DMA mapping */
buffer->unmap_len = st->unmap_len;
buffer->dma_offset = buffer->unmap_len - buffer->len;
- buffer->flags |= st->dma_flags;
st->unmap_len = 0;
}
* @st: TSO state
*
* Generate a new header and prepare for the new packet. Return 0 on
- * success, or -%ENOMEM if failed to alloc header.
+ * success, or -%ENOMEM if failed to alloc header, or other negative error.
*/
static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
const struct sk_buff *skb,
struct efx_tx_buffer *buffer =
efx_tx_queue_get_insert_buffer(tx_queue);
bool is_last = st->out_len <= skb_shinfo(skb)->gso_size;
- u8 tcp_flags_mask;
+ u8 tcp_flags_mask, tcp_flags;
if (!is_last) {
st->packet_space = skb_shinfo(skb)->gso_size;
tcp_flags_mask = 0x00;
}
- if (!st->header_unmap_len) {
- /* Allocate and insert a DMA-mapped header buffer. */
- struct tcphdr *tsoh_th;
- unsigned int ip_length;
- u8 *header;
- int rc;
-
- header = efx_tsoh_get_buffer(tx_queue, buffer, st->header_len);
- if (!header)
- return -ENOMEM;
-
- tsoh_th = (struct tcphdr *)(header + st->tcp_off);
-
- /* Copy and update the headers. */
- memcpy(header, skb->data, st->header_len);
-
- tsoh_th->seq = htonl(st->seqnum);
- ((u8 *)tsoh_th)[TCP_FLAGS_OFFSET] &= ~tcp_flags_mask;
-
- ip_length = st->ip_base_len + st->packet_space;
-
- if (st->protocol == htons(ETH_P_IP)) {
- struct iphdr *tsoh_iph =
- (struct iphdr *)(header + st->ip_off);
-
- tsoh_iph->tot_len = htons(ip_length);
- tsoh_iph->id = htons(st->ipv4_id);
- } else {
- struct ipv6hdr *tsoh_iph =
- (struct ipv6hdr *)(header + st->ip_off);
-
- tsoh_iph->payload_len = htons(ip_length);
- }
+ if (WARN_ON(!st->header_unmap_len))
+ return -EINVAL;
+ /* Send the original headers with a TSO option descriptor
+ * in front
+ */
+ tcp_flags = ((u8 *)tcp_hdr(skb))[TCP_FLAGS_OFFSET] & ~tcp_flags_mask;
+
+ buffer->flags = EFX_TX_BUF_OPTION;
+ buffer->len = 0;
+ buffer->unmap_len = 0;
+ EFX_POPULATE_QWORD_5(buffer->option,
+ ESF_DZ_TX_DESC_IS_OPT, 1,
+ ESF_DZ_TX_OPTION_TYPE,
+ ESE_DZ_TX_OPTION_DESC_TSO,
+ ESF_DZ_TX_TSO_TCP_FLAGS, tcp_flags,
+ ESF_DZ_TX_TSO_IP_ID, st->ipv4_id,
+ ESF_DZ_TX_TSO_TCP_SEQNO, st->seqnum);
+ ++tx_queue->insert_count;
- rc = efx_tso_put_header(tx_queue, buffer, header);
- if (unlikely(rc))
- return rc;
- } else {
- /* Send the original headers with a TSO option descriptor
- * in front
+ /* We mapped the headers in tso_start(). Unmap them
+ * when the last segment is completed.
+ */
+ buffer = efx_tx_queue_get_insert_buffer(tx_queue);
+ buffer->dma_addr = st->header_dma_addr;
+ buffer->len = st->header_len;
+ if (is_last) {
+ buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_MAP_SINGLE;
+ buffer->unmap_len = st->header_unmap_len;
+ buffer->dma_offset = 0;
+ /* Ensure we only unmap them once in case of a
+ * later DMA mapping error and rollback
*/
- u8 tcp_flags = ((u8 *)tcp_hdr(skb))[TCP_FLAGS_OFFSET] &
- ~tcp_flags_mask;
-
- buffer->flags = EFX_TX_BUF_OPTION;
- buffer->len = 0;
+ st->header_unmap_len = 0;
+ } else {
+ buffer->flags = EFX_TX_BUF_CONT;
buffer->unmap_len = 0;
- EFX_POPULATE_QWORD_5(buffer->option,
- ESF_DZ_TX_DESC_IS_OPT, 1,
- ESF_DZ_TX_OPTION_TYPE,
- ESE_DZ_TX_OPTION_DESC_TSO,
- ESF_DZ_TX_TSO_TCP_FLAGS, tcp_flags,
- ESF_DZ_TX_TSO_IP_ID, st->ipv4_id,
- ESF_DZ_TX_TSO_TCP_SEQNO, st->seqnum);
- ++tx_queue->insert_count;
-
- /* We mapped the headers in tso_start(). Unmap them
- * when the last segment is completed.
- */
- buffer = efx_tx_queue_get_insert_buffer(tx_queue);
- buffer->dma_addr = st->header_dma_addr;
- buffer->len = st->header_len;
- if (is_last) {
- buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_MAP_SINGLE;
- buffer->unmap_len = st->header_unmap_len;
- buffer->dma_offset = 0;
- /* Ensure we only unmap them once in case of a
- * later DMA mapping error and rollback
- */
- st->header_unmap_len = 0;
- } else {
- buffer->flags = EFX_TX_BUF_CONT;
- buffer->unmap_len = 0;
- }
- ++tx_queue->insert_count;
}
+ ++tx_queue->insert_count;
st->seqnum += skb_shinfo(skb)->gso_size;
* 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.
+ * @skb was not enqueued. @skb is consumed unless return value is
+ * %EINVAL.
*/
int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue,
struct sk_buff *skb,
int frag_i, rc;
struct tso_state state;
+ if (tx_queue->tso_version != 1)
+ return -EINVAL;
+
prefetch(skb->data);
/* Find the packet protocol and sanity-check it */
rc = tso_start(&state, efx, tx_queue, skb);
if (rc)
- goto mem_err;
+ goto fail;
if (likely(state.in_len == 0)) {
/* Grab the first payload fragment. */
rc = tso_get_fragment(&state, efx,
skb_shinfo(skb)->frags + frag_i);
if (rc)
- goto mem_err;
+ goto fail;
} else {
/* Payload starts in the header area. */
frag_i = -1;
}
- if (tso_start_new_packet(tx_queue, skb, &state) < 0)
- goto mem_err;
+ rc = tso_start_new_packet(tx_queue, skb, &state);
+ if (rc)
+ goto fail;
prefetch_ptr(tx_queue);
rc = tso_get_fragment(&state, efx,
skb_shinfo(skb)->frags + frag_i);
if (rc)
- goto mem_err;
+ goto fail;
}
/* Start at new packet? */
- if (state.packet_space == 0 &&
- tso_start_new_packet(tx_queue, skb, &state) < 0)
- goto mem_err;
+ if (state.packet_space == 0) {
+ rc = tso_start_new_packet(tx_queue, skb, &state);
+ if (rc)
+ goto fail;
+ }
}
*data_mapped = true;
return 0;
- mem_err:
- netif_err(efx, tx_err, efx->net_dev,
- "Out of memory for TSO headers, or DMA mapping error\n");
+fail:
+ if (rc == -ENOMEM)
+ netif_err(efx, tx_err, efx->net_dev,
+ "Out of memory for TSO headers, or DMA mapping error\n");
+ else
+ netif_err(efx, tx_err, efx->net_dev, "TSO failed, rc = %d\n", rc);
/* Free the DMA mapping we were in the process of writing out */
if (state.unmap_len) {
- if (state.dma_flags & EFX_TX_BUF_MAP_SINGLE)
- dma_unmap_single(&efx->pci_dev->dev, state.unmap_addr,
- state.unmap_len, DMA_TO_DEVICE);
- else
- dma_unmap_page(&efx->pci_dev->dev, state.unmap_addr,
- state.unmap_len, DMA_TO_DEVICE);
+ dma_unmap_page(&efx->pci_dev->dev, state.unmap_addr,
+ state.unmap_len, DMA_TO_DEVICE);
}
- /* Free the header DMA mapping, if using option descriptors */
+ /* Free the header DMA mapping */
if (state.header_unmap_len)
dma_unmap_single(&efx->pci_dev->dev, state.header_dma_addr,
state.header_unmap_len, DMA_TO_DEVICE);
- return -ENOMEM;
+ return rc;
}
projects / karo-tx-linux.git / commitdiff