static int efx_enqueue_skb_copy(struct efx_tx_queue *tx_queue,
struct sk_buff *skb)
{
unsigned int copy_len = skb->len;
struct efx_tx_buffer *buffer;
u8 *copy_buffer;
int rc;
EFX_WARN_ON_ONCE_PARANOID(copy_len > EFX_TX_CB_SIZE);
buffer = efx_tx_queue_get_insert_buffer(tx_queue);
copy_buffer = efx_tx_get_copy_buffer(tx_queue, buffer);
if (unlikely(!copy_buffer))
return -ENOMEM;
rc = skb_copy_bits(skb, 0, copy_buffer, copy_len);
EFX_WARN_ON_PARANOID(rc);
buffer->len = copy_len;
buffer->skb = skb;
buffer->flags = EFX_TX_BUF_SKB;
++tx_queue->insert_count;
return rc;
}
/**
* 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
* @final_buffer: The final buffer inserted into the queue
*
* Push descriptors onto the TX queue.
*/
static void efx_tx_queue_insert(struct efx_tx_queue *tx_queue,
dma_addr_t dma_addr, unsigned int len,
struct efx_tx_buffer **final_buffer)
{
struct efx_tx_buffer *buffer;
unsigned int dma_len;
EFX_WARN_ON_ONCE_PARANOID(len <= 0);
while (1) {
buffer = efx_tx_queue_get_insert_buffer(tx_queue);
++tx_queue->insert_count;
EFX_WARN_ON_ONCE_PARANOID(tx_queue->insert_count -
tx_queue->read_count >=
tx_queue->efx->txq_entries);
buffer->dma_addr = dma_addr;
dma_len = tx_queue->efx->type->tx_limit_len(tx_queue,
dma_addr, len);
/* If there's space for everything this is our last buffer. */
if (dma_len >= len)
break;
buffer->len = dma_len;
buffer->flags = EFX_TX_BUF_CONT;
dma_addr += dma_len;
len -= dma_len;
}
EFX_WARN_ON_ONCE_PARANOID(!len);
buffer->len = len;
*final_buffer = buffer;
}
/**
* 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
* @is_first: true if this is the first packet
*
* Generate a new header and prepare for the new packet. Return 0 on
* success, or -%ENOMEM if failed to alloc header.
*/
static int tso_start_new_packet(struct efx_tx_queue *tx_queue,
const struct sk_buff *skb,
struct tso_state *st,
bool is_first)
{
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;
if (!is_last) {
st->packet_space = skb_shinfo(skb)->gso_size;
tcp_flags_mask = TCPHDR_FIN | TCPHDR_PSH;
} else {
st->packet_space = st->out_len;
tcp_flags_mask = 0;
}
if (!is_first)
tcp_flags_mask |= TCPHDR_CWR; /* Congestion control */
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);
tcp_flag_byte(tsoh_th) &= ~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);
}
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
*/
u8 tcp_flags = tcp_flag_byte(tcp_hdr(skb)) & ~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;
/* 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;
}
st->seqnum += skb_shinfo(skb)->gso_size;
/* Linux leaves suitable gaps in the IP ID space for us to fill. */
++st->ipv4_id;
return 0;
}
