1 /****************************************************************************
2 * Driver for Solarflare Solarstorm network controllers and boards
3 * Copyright 2005-2006 Fen Systems Ltd.
4 * Copyright 2005-2008 Solarflare Communications Inc.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation, incorporated herein by reference.
11 #include <linux/pci.h>
12 #include <linux/tcp.h>
15 #include <linux/if_ether.h>
16 #include <linux/highmem.h>
17 #include "net_driver.h"
21 #include "workarounds.h"
24 * TX descriptor ring full threshold
26 * The tx_queue descriptor ring fill-level must fall below this value
27 * before we restart the netif queue
29 #define EFX_NETDEV_TX_THRESHOLD(_tx_queue) \
30 (_tx_queue->efx->type->txd_ring_mask / 2u)
32 /* We want to be able to nest calls to netif_stop_queue(), since each
33 * channel can have an individual stop on the queue.
35 void efx_stop_queue(struct efx_nic
*efx
)
37 spin_lock_bh(&efx
->netif_stop_lock
);
38 EFX_TRACE(efx
, "stop TX queue\n");
40 atomic_inc(&efx
->netif_stop_count
);
41 netif_stop_queue(efx
->net_dev
);
43 spin_unlock_bh(&efx
->netif_stop_lock
);
46 /* Wake netif's TX queue
47 * We want to be able to nest calls to netif_stop_queue(), since each
48 * channel can have an individual stop on the queue.
50 void efx_wake_queue(struct efx_nic
*efx
)
53 if (atomic_dec_and_lock(&efx
->netif_stop_count
,
54 &efx
->netif_stop_lock
)) {
55 EFX_TRACE(efx
, "waking TX queue\n");
56 netif_wake_queue(efx
->net_dev
);
57 spin_unlock(&efx
->netif_stop_lock
);
62 static void efx_dequeue_buffer(struct efx_tx_queue
*tx_queue
,
63 struct efx_tx_buffer
*buffer
)
65 if (buffer
->unmap_len
) {
66 struct pci_dev
*pci_dev
= tx_queue
->efx
->pci_dev
;
67 dma_addr_t unmap_addr
= (buffer
->dma_addr
+ buffer
->len
-
69 if (buffer
->unmap_single
)
70 pci_unmap_single(pci_dev
, unmap_addr
, buffer
->unmap_len
,
73 pci_unmap_page(pci_dev
, unmap_addr
, buffer
->unmap_len
,
75 buffer
->unmap_len
= 0;
76 buffer
->unmap_single
= false;
80 dev_kfree_skb_any((struct sk_buff
*) buffer
->skb
);
82 EFX_TRACE(tx_queue
->efx
, "TX queue %d transmission id %x "
83 "complete\n", tx_queue
->queue
, read_ptr
);
88 * struct efx_tso_header - a DMA mapped buffer for packet headers
89 * @next: Linked list of free ones.
90 * The list is protected by the TX queue lock.
91 * @dma_unmap_len: Length to unmap for an oversize buffer, or 0.
92 * @dma_addr: The DMA address of the header below.
94 * This controls the memory used for a TSO header. Use TSOH_DATA()
95 * to find the packet header data. Use TSOH_SIZE() to calculate the
96 * total size required for a given packet header length. TSO headers
97 * in the free list are exactly %TSOH_STD_SIZE bytes in size.
99 struct efx_tso_header
{
101 struct efx_tso_header
*next
;
107 static int efx_enqueue_skb_tso(struct efx_tx_queue
*tx_queue
,
108 struct sk_buff
*skb
);
109 static void efx_fini_tso(struct efx_tx_queue
*tx_queue
);
110 static void efx_tsoh_heap_free(struct efx_tx_queue
*tx_queue
,
111 struct efx_tso_header
*tsoh
);
113 static void efx_tsoh_free(struct efx_tx_queue
*tx_queue
,
114 struct efx_tx_buffer
*buffer
)
117 if (likely(!buffer
->tsoh
->unmap_len
)) {
118 buffer
->tsoh
->next
= tx_queue
->tso_headers_free
;
119 tx_queue
->tso_headers_free
= buffer
->tsoh
;
121 efx_tsoh_heap_free(tx_queue
, buffer
->tsoh
);
129 * Add a socket buffer to a TX queue
131 * This maps all fragments of a socket buffer for DMA and adds them to
132 * the TX queue. The queue's insert pointer will be incremented by
133 * the number of fragments in the socket buffer.
135 * If any DMA mapping fails, any mapped fragments will be unmapped,
136 * the queue's insert pointer will be restored to its original value.
138 * Returns NETDEV_TX_OK or NETDEV_TX_BUSY
139 * You must hold netif_tx_lock() to call this function.
141 static int efx_enqueue_skb(struct efx_tx_queue
*tx_queue
,
144 struct efx_nic
*efx
= tx_queue
->efx
;
145 struct pci_dev
*pci_dev
= efx
->pci_dev
;
146 struct efx_tx_buffer
*buffer
;
147 skb_frag_t
*fragment
;
150 unsigned int len
, unmap_len
= 0, fill_level
, insert_ptr
, misalign
;
151 dma_addr_t dma_addr
, unmap_addr
= 0;
152 unsigned int dma_len
;
155 int rc
= NETDEV_TX_OK
;
157 EFX_BUG_ON_PARANOID(tx_queue
->write_count
!= tx_queue
->insert_count
);
159 if (skb_shinfo((struct sk_buff
*)skb
)->gso_size
)
160 return efx_enqueue_skb_tso(tx_queue
, skb
);
162 /* Get size of the initial fragment */
163 len
= skb_headlen(skb
);
165 /* Pad if necessary */
166 if (EFX_WORKAROUND_15592(efx
) && skb
->len
<= 32) {
167 EFX_BUG_ON_PARANOID(skb
->data_len
);
169 if (skb_pad(skb
, len
- skb
->len
))
173 fill_level
= tx_queue
->insert_count
- tx_queue
->old_read_count
;
174 q_space
= efx
->type
->txd_ring_mask
- 1 - fill_level
;
176 /* Map for DMA. Use pci_map_single rather than pci_map_page
177 * since this is more efficient on machines with sparse
181 dma_addr
= pci_map_single(pci_dev
, skb
->data
, len
, PCI_DMA_TODEVICE
);
183 /* Process all fragments */
185 if (unlikely(pci_dma_mapping_error(pci_dev
, dma_addr
)))
188 /* Store fields for marking in the per-fragment final
191 unmap_addr
= dma_addr
;
193 /* Add to TX queue, splitting across DMA boundaries */
195 if (unlikely(q_space
-- <= 0)) {
196 /* It might be that completions have
197 * happened since the xmit path last
198 * checked. Update the xmit path's
199 * copy of read_count.
202 /* This memory barrier protects the
203 * change of stopped from the access
206 tx_queue
->old_read_count
=
207 *(volatile unsigned *)
208 &tx_queue
->read_count
;
209 fill_level
= (tx_queue
->insert_count
210 - tx_queue
->old_read_count
);
211 q_space
= (efx
->type
->txd_ring_mask
- 1 -
213 if (unlikely(q_space
-- <= 0))
219 insert_ptr
= (tx_queue
->insert_count
&
220 efx
->type
->txd_ring_mask
);
221 buffer
= &tx_queue
->buffer
[insert_ptr
];
222 efx_tsoh_free(tx_queue
, buffer
);
223 EFX_BUG_ON_PARANOID(buffer
->tsoh
);
224 EFX_BUG_ON_PARANOID(buffer
->skb
);
225 EFX_BUG_ON_PARANOID(buffer
->len
);
226 EFX_BUG_ON_PARANOID(!buffer
->continuation
);
227 EFX_BUG_ON_PARANOID(buffer
->unmap_len
);
229 dma_len
= (((~dma_addr
) & efx
->type
->tx_dma_mask
) + 1);
230 if (likely(dma_len
> len
))
233 misalign
= (unsigned)dma_addr
& efx
->type
->bug5391_mask
;
234 if (misalign
&& dma_len
+ misalign
> 512)
235 dma_len
= 512 - misalign
;
237 /* Fill out per descriptor fields */
238 buffer
->len
= dma_len
;
239 buffer
->dma_addr
= dma_addr
;
242 ++tx_queue
->insert_count
;
245 /* Transfer ownership of the unmapping to the final buffer */
246 buffer
->unmap_single
= unmap_single
;
247 buffer
->unmap_len
= unmap_len
;
250 /* Get address and size of next fragment */
251 if (i
>= skb_shinfo(skb
)->nr_frags
)
253 fragment
= &skb_shinfo(skb
)->frags
[i
];
254 len
= fragment
->size
;
255 page
= fragment
->page
;
256 page_offset
= fragment
->page_offset
;
259 unmap_single
= false;
260 dma_addr
= pci_map_page(pci_dev
, page
, page_offset
, len
,
264 /* Transfer ownership of the skb to the final buffer */
266 buffer
->continuation
= false;
268 /* Pass off to hardware */
269 falcon_push_buffers(tx_queue
);
274 EFX_ERR_RL(efx
, " TX queue %d could not map skb with %d bytes %d "
275 "fragments for DMA\n", tx_queue
->queue
, skb
->len
,
276 skb_shinfo(skb
)->nr_frags
+ 1);
278 /* Mark the packet as transmitted, and free the SKB ourselves */
279 dev_kfree_skb_any((struct sk_buff
*)skb
);
285 if (tx_queue
->stopped
== 1)
289 /* Work backwards until we hit the original insert pointer value */
290 while (tx_queue
->insert_count
!= tx_queue
->write_count
) {
291 --tx_queue
->insert_count
;
292 insert_ptr
= tx_queue
->insert_count
& efx
->type
->txd_ring_mask
;
293 buffer
= &tx_queue
->buffer
[insert_ptr
];
294 efx_dequeue_buffer(tx_queue
, buffer
);
298 /* Free the fragment we were mid-way through pushing */
301 pci_unmap_single(pci_dev
, unmap_addr
, unmap_len
,
304 pci_unmap_page(pci_dev
, unmap_addr
, unmap_len
,
311 /* Remove packets from the TX queue
313 * This removes packets from the TX queue, up to and including the
316 static void efx_dequeue_buffers(struct efx_tx_queue
*tx_queue
,
319 struct efx_nic
*efx
= tx_queue
->efx
;
320 unsigned int stop_index
, read_ptr
;
321 unsigned int mask
= tx_queue
->efx
->type
->txd_ring_mask
;
323 stop_index
= (index
+ 1) & mask
;
324 read_ptr
= tx_queue
->read_count
& mask
;
326 while (read_ptr
!= stop_index
) {
327 struct efx_tx_buffer
*buffer
= &tx_queue
->buffer
[read_ptr
];
328 if (unlikely(buffer
->len
== 0)) {
329 EFX_ERR(tx_queue
->efx
, "TX queue %d spurious TX "
330 "completion id %x\n", tx_queue
->queue
,
332 efx_schedule_reset(efx
, RESET_TYPE_TX_SKIP
);
336 efx_dequeue_buffer(tx_queue
, buffer
);
337 buffer
->continuation
= true;
340 ++tx_queue
->read_count
;
341 read_ptr
= tx_queue
->read_count
& mask
;
345 /* Initiate a packet transmission on the specified TX queue.
346 * Note that returning anything other than NETDEV_TX_OK will cause the
347 * OS to free the skb.
349 * This function is split out from efx_hard_start_xmit to allow the
350 * loopback test to direct packets via specific TX queues. It is
351 * therefore a non-static inline, so as not to penalise performance
352 * for non-loopback transmissions.
354 * Context: netif_tx_lock held
356 inline int efx_xmit(struct efx_nic
*efx
,
357 struct efx_tx_queue
*tx_queue
, struct sk_buff
*skb
)
361 /* Map fragments for DMA and add to TX queue */
362 rc
= efx_enqueue_skb(tx_queue
, skb
);
366 /* Initiate a packet transmission. We use one channel per CPU
367 * (sharing when we have more CPUs than channels). On Falcon, the TX
368 * completion events will be directed back to the CPU that transmitted
369 * the packet, which should be cache-efficient.
371 * Context: non-blocking.
372 * Note that returning anything other than NETDEV_TX_OK will cause the
373 * OS to free the skb.
375 int efx_hard_start_xmit(struct sk_buff
*skb
, struct net_device
*net_dev
)
377 struct efx_nic
*efx
= netdev_priv(net_dev
);
378 struct efx_tx_queue
*tx_queue
;
380 if (unlikely(efx
->port_inhibited
))
381 return NETDEV_TX_BUSY
;
383 if (likely(skb
->ip_summed
== CHECKSUM_PARTIAL
))
384 tx_queue
= &efx
->tx_queue
[EFX_TX_QUEUE_OFFLOAD_CSUM
];
386 tx_queue
= &efx
->tx_queue
[EFX_TX_QUEUE_NO_CSUM
];
388 return efx_xmit(efx
, tx_queue
, skb
);
391 void efx_xmit_done(struct efx_tx_queue
*tx_queue
, unsigned int index
)
394 struct efx_nic
*efx
= tx_queue
->efx
;
396 EFX_BUG_ON_PARANOID(index
> efx
->type
->txd_ring_mask
);
398 efx_dequeue_buffers(tx_queue
, index
);
400 /* See if we need to restart the netif queue. This barrier
401 * separates the update of read_count from the test of
404 if (unlikely(tx_queue
->stopped
) && likely(efx
->port_enabled
)) {
405 fill_level
= tx_queue
->insert_count
- tx_queue
->read_count
;
406 if (fill_level
< EFX_NETDEV_TX_THRESHOLD(tx_queue
)) {
407 EFX_BUG_ON_PARANOID(!efx_dev_registered(efx
));
409 /* Do this under netif_tx_lock(), to avoid racing
410 * with efx_xmit(). */
411 netif_tx_lock(efx
->net_dev
);
412 if (tx_queue
->stopped
) {
413 tx_queue
->stopped
= 0;
416 netif_tx_unlock(efx
->net_dev
);
421 int efx_probe_tx_queue(struct efx_tx_queue
*tx_queue
)
423 struct efx_nic
*efx
= tx_queue
->efx
;
424 unsigned int txq_size
;
427 EFX_LOG(efx
, "creating TX queue %d\n", tx_queue
->queue
);
429 /* Allocate software ring */
430 txq_size
= (efx
->type
->txd_ring_mask
+ 1) * sizeof(*tx_queue
->buffer
);
431 tx_queue
->buffer
= kzalloc(txq_size
, GFP_KERNEL
);
432 if (!tx_queue
->buffer
)
434 for (i
= 0; i
<= efx
->type
->txd_ring_mask
; ++i
)
435 tx_queue
->buffer
[i
].continuation
= true;
437 /* Allocate hardware ring */
438 rc
= falcon_probe_tx(tx_queue
);
445 kfree(tx_queue
->buffer
);
446 tx_queue
->buffer
= NULL
;
450 void efx_init_tx_queue(struct efx_tx_queue
*tx_queue
)
452 EFX_LOG(tx_queue
->efx
, "initialising TX queue %d\n", tx_queue
->queue
);
454 tx_queue
->insert_count
= 0;
455 tx_queue
->write_count
= 0;
456 tx_queue
->read_count
= 0;
457 tx_queue
->old_read_count
= 0;
458 BUG_ON(tx_queue
->stopped
);
460 /* Set up TX descriptor ring */
461 falcon_init_tx(tx_queue
);
464 void efx_release_tx_buffers(struct efx_tx_queue
*tx_queue
)
466 struct efx_tx_buffer
*buffer
;
468 if (!tx_queue
->buffer
)
471 /* Free any buffers left in the ring */
472 while (tx_queue
->read_count
!= tx_queue
->write_count
) {
473 buffer
= &tx_queue
->buffer
[tx_queue
->read_count
&
474 tx_queue
->efx
->type
->txd_ring_mask
];
475 efx_dequeue_buffer(tx_queue
, buffer
);
476 buffer
->continuation
= true;
479 ++tx_queue
->read_count
;
483 void efx_fini_tx_queue(struct efx_tx_queue
*tx_queue
)
485 EFX_LOG(tx_queue
->efx
, "shutting down TX queue %d\n", tx_queue
->queue
);
487 /* Flush TX queue, remove descriptor ring */
488 falcon_fini_tx(tx_queue
);
490 efx_release_tx_buffers(tx_queue
);
492 /* Free up TSO header cache */
493 efx_fini_tso(tx_queue
);
495 /* Release queue's stop on port, if any */
496 if (tx_queue
->stopped
) {
497 tx_queue
->stopped
= 0;
498 efx_wake_queue(tx_queue
->efx
);
502 void efx_remove_tx_queue(struct efx_tx_queue
*tx_queue
)
504 EFX_LOG(tx_queue
->efx
, "destroying TX queue %d\n", tx_queue
->queue
);
505 falcon_remove_tx(tx_queue
);
507 kfree(tx_queue
->buffer
);
508 tx_queue
->buffer
= NULL
;
512 /* Efx TCP segmentation acceleration.
514 * Why? Because by doing it here in the driver we can go significantly
515 * faster than the GSO.
517 * Requires TX checksum offload support.
520 /* Number of bytes inserted at the start of a TSO header buffer,
521 * similar to NET_IP_ALIGN.
523 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
524 #define TSOH_OFFSET 0
526 #define TSOH_OFFSET NET_IP_ALIGN
529 #define TSOH_BUFFER(tsoh) ((u8 *)(tsoh + 1) + TSOH_OFFSET)
531 /* Total size of struct efx_tso_header, buffer and padding */
532 #define TSOH_SIZE(hdr_len) \
533 (sizeof(struct efx_tso_header) + TSOH_OFFSET + hdr_len)
535 /* Size of blocks on free list. Larger blocks must be allocated from
538 #define TSOH_STD_SIZE 128
540 #define PTR_DIFF(p1, p2) ((u8 *)(p1) - (u8 *)(p2))
541 #define ETH_HDR_LEN(skb) (skb_network_header(skb) - (skb)->data)
542 #define SKB_TCP_OFF(skb) PTR_DIFF(tcp_hdr(skb), (skb)->data)
543 #define SKB_IPV4_OFF(skb) PTR_DIFF(ip_hdr(skb), (skb)->data)
546 * struct tso_state - TSO state for an SKB
547 * @out_len: Remaining length in current segment
548 * @seqnum: Current sequence number
549 * @ipv4_id: Current IPv4 ID, host endian
550 * @packet_space: Remaining space in current packet
551 * @dma_addr: DMA address of current position
552 * @in_len: Remaining length in current SKB fragment
553 * @unmap_len: Length of SKB fragment
554 * @unmap_addr: DMA address of SKB fragment
555 * @unmap_single: DMA single vs page mapping flag
556 * @header_len: Number of bytes of header
557 * @full_packet_size: Number of bytes to put in each outgoing segment
559 * The state used during segmentation. It is put into this data structure
560 * just to make it easy to pass into inline functions.
563 /* Output position */
567 unsigned packet_space
;
573 dma_addr_t unmap_addr
;
577 int full_packet_size
;
582 * Verify that our various assumptions about sk_buffs and the conditions
583 * under which TSO will be attempted hold true.
585 static void efx_tso_check_safe(struct sk_buff
*skb
)
587 __be16 protocol
= skb
->protocol
;
589 EFX_BUG_ON_PARANOID(((struct ethhdr
*)skb
->data
)->h_proto
!=
591 if (protocol
== htons(ETH_P_8021Q
)) {
592 /* Find the encapsulated protocol; reset network header
593 * and transport header based on that. */
594 struct vlan_ethhdr
*veh
= (struct vlan_ethhdr
*)skb
->data
;
595 protocol
= veh
->h_vlan_encapsulated_proto
;
596 skb_set_network_header(skb
, sizeof(*veh
));
597 if (protocol
== htons(ETH_P_IP
))
598 skb_set_transport_header(skb
, sizeof(*veh
) +
599 4 * ip_hdr(skb
)->ihl
);
602 EFX_BUG_ON_PARANOID(protocol
!= htons(ETH_P_IP
));
603 EFX_BUG_ON_PARANOID(ip_hdr(skb
)->protocol
!= IPPROTO_TCP
);
604 EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb
), skb
->data
)
605 + (tcp_hdr(skb
)->doff
<< 2u)) >
611 * Allocate a page worth of efx_tso_header structures, and string them
612 * into the tx_queue->tso_headers_free linked list. Return 0 or -ENOMEM.
614 static int efx_tsoh_block_alloc(struct efx_tx_queue
*tx_queue
)
617 struct pci_dev
*pci_dev
= tx_queue
->efx
->pci_dev
;
618 struct efx_tso_header
*tsoh
;
622 base_kva
= pci_alloc_consistent(pci_dev
, PAGE_SIZE
, &dma_addr
);
623 if (base_kva
== NULL
) {
624 EFX_ERR(tx_queue
->efx
, "Unable to allocate page for TSO"
629 /* pci_alloc_consistent() allocates pages. */
630 EFX_BUG_ON_PARANOID(dma_addr
& (PAGE_SIZE
- 1u));
632 for (kva
= base_kva
; kva
< base_kva
+ PAGE_SIZE
; kva
+= TSOH_STD_SIZE
) {
633 tsoh
= (struct efx_tso_header
*)kva
;
634 tsoh
->dma_addr
= dma_addr
+ (TSOH_BUFFER(tsoh
) - base_kva
);
635 tsoh
->next
= tx_queue
->tso_headers_free
;
636 tx_queue
->tso_headers_free
= tsoh
;
643 /* Free up a TSO header, and all others in the same page. */
644 static void efx_tsoh_block_free(struct efx_tx_queue
*tx_queue
,
645 struct efx_tso_header
*tsoh
,
646 struct pci_dev
*pci_dev
)
648 struct efx_tso_header
**p
;
649 unsigned long base_kva
;
652 base_kva
= (unsigned long)tsoh
& PAGE_MASK
;
653 base_dma
= tsoh
->dma_addr
& PAGE_MASK
;
655 p
= &tx_queue
->tso_headers_free
;
657 if (((unsigned long)*p
& PAGE_MASK
) == base_kva
)
663 pci_free_consistent(pci_dev
, PAGE_SIZE
, (void *)base_kva
, base_dma
);
666 static struct efx_tso_header
*
667 efx_tsoh_heap_alloc(struct efx_tx_queue
*tx_queue
, size_t header_len
)
669 struct efx_tso_header
*tsoh
;
671 tsoh
= kmalloc(TSOH_SIZE(header_len
), GFP_ATOMIC
| GFP_DMA
);
675 tsoh
->dma_addr
= pci_map_single(tx_queue
->efx
->pci_dev
,
676 TSOH_BUFFER(tsoh
), header_len
,
678 if (unlikely(pci_dma_mapping_error(tx_queue
->efx
->pci_dev
,
684 tsoh
->unmap_len
= header_len
;
689 efx_tsoh_heap_free(struct efx_tx_queue
*tx_queue
, struct efx_tso_header
*tsoh
)
691 pci_unmap_single(tx_queue
->efx
->pci_dev
,
692 tsoh
->dma_addr
, tsoh
->unmap_len
,
698 * efx_tx_queue_insert - push descriptors onto the TX queue
699 * @tx_queue: Efx TX queue
700 * @dma_addr: DMA address of fragment
701 * @len: Length of fragment
702 * @final_buffer: The final buffer inserted into the queue
704 * Push descriptors onto the TX queue. Return 0 on success or 1 if
707 static int efx_tx_queue_insert(struct efx_tx_queue
*tx_queue
,
708 dma_addr_t dma_addr
, unsigned len
,
709 struct efx_tx_buffer
**final_buffer
)
711 struct efx_tx_buffer
*buffer
;
712 struct efx_nic
*efx
= tx_queue
->efx
;
713 unsigned dma_len
, fill_level
, insert_ptr
, misalign
;
716 EFX_BUG_ON_PARANOID(len
<= 0);
718 fill_level
= tx_queue
->insert_count
- tx_queue
->old_read_count
;
719 /* -1 as there is no way to represent all descriptors used */
720 q_space
= efx
->type
->txd_ring_mask
- 1 - fill_level
;
723 if (unlikely(q_space
-- <= 0)) {
724 /* It might be that completions have happened
725 * since the xmit path last checked. Update
726 * the xmit path's copy of read_count.
729 /* This memory barrier protects the change of
730 * stopped from the access of read_count. */
732 tx_queue
->old_read_count
=
733 *(volatile unsigned *)&tx_queue
->read_count
;
734 fill_level
= (tx_queue
->insert_count
735 - tx_queue
->old_read_count
);
736 q_space
= efx
->type
->txd_ring_mask
- 1 - fill_level
;
737 if (unlikely(q_space
-- <= 0)) {
738 *final_buffer
= NULL
;
745 insert_ptr
= tx_queue
->insert_count
& efx
->type
->txd_ring_mask
;
746 buffer
= &tx_queue
->buffer
[insert_ptr
];
747 ++tx_queue
->insert_count
;
749 EFX_BUG_ON_PARANOID(tx_queue
->insert_count
-
750 tx_queue
->read_count
>
751 efx
->type
->txd_ring_mask
);
753 efx_tsoh_free(tx_queue
, buffer
);
754 EFX_BUG_ON_PARANOID(buffer
->len
);
755 EFX_BUG_ON_PARANOID(buffer
->unmap_len
);
756 EFX_BUG_ON_PARANOID(buffer
->skb
);
757 EFX_BUG_ON_PARANOID(!buffer
->continuation
);
758 EFX_BUG_ON_PARANOID(buffer
->tsoh
);
760 buffer
->dma_addr
= dma_addr
;
762 /* Ensure we do not cross a boundary unsupported by H/W */
763 dma_len
= (~dma_addr
& efx
->type
->tx_dma_mask
) + 1;
765 misalign
= (unsigned)dma_addr
& efx
->type
->bug5391_mask
;
766 if (misalign
&& dma_len
+ misalign
> 512)
767 dma_len
= 512 - misalign
;
769 /* If there is enough space to send then do so */
773 buffer
->len
= dma_len
; /* Don't set the other members */
778 EFX_BUG_ON_PARANOID(!len
);
780 *final_buffer
= buffer
;
786 * Put a TSO header into the TX queue.
788 * This is special-cased because we know that it is small enough to fit in
789 * a single fragment, and we know it doesn't cross a page boundary. It
790 * also allows us to not worry about end-of-packet etc.
792 static void efx_tso_put_header(struct efx_tx_queue
*tx_queue
,
793 struct efx_tso_header
*tsoh
, unsigned len
)
795 struct efx_tx_buffer
*buffer
;
797 buffer
= &tx_queue
->buffer
[tx_queue
->insert_count
&
798 tx_queue
->efx
->type
->txd_ring_mask
];
799 efx_tsoh_free(tx_queue
, buffer
);
800 EFX_BUG_ON_PARANOID(buffer
->len
);
801 EFX_BUG_ON_PARANOID(buffer
->unmap_len
);
802 EFX_BUG_ON_PARANOID(buffer
->skb
);
803 EFX_BUG_ON_PARANOID(!buffer
->continuation
);
804 EFX_BUG_ON_PARANOID(buffer
->tsoh
);
806 buffer
->dma_addr
= tsoh
->dma_addr
;
809 ++tx_queue
->insert_count
;
813 /* Remove descriptors put into a tx_queue. */
814 static void efx_enqueue_unwind(struct efx_tx_queue
*tx_queue
)
816 struct efx_tx_buffer
*buffer
;
817 dma_addr_t unmap_addr
;
819 /* Work backwards until we hit the original insert pointer value */
820 while (tx_queue
->insert_count
!= tx_queue
->write_count
) {
821 --tx_queue
->insert_count
;
822 buffer
= &tx_queue
->buffer
[tx_queue
->insert_count
&
823 tx_queue
->efx
->type
->txd_ring_mask
];
824 efx_tsoh_free(tx_queue
, buffer
);
825 EFX_BUG_ON_PARANOID(buffer
->skb
);
827 buffer
->continuation
= true;
828 if (buffer
->unmap_len
) {
829 unmap_addr
= (buffer
->dma_addr
+ buffer
->len
-
831 if (buffer
->unmap_single
)
832 pci_unmap_single(tx_queue
->efx
->pci_dev
,
833 unmap_addr
, buffer
->unmap_len
,
836 pci_unmap_page(tx_queue
->efx
->pci_dev
,
837 unmap_addr
, buffer
->unmap_len
,
839 buffer
->unmap_len
= 0;
845 /* Parse the SKB header and initialise state. */
846 static void tso_start(struct tso_state
*st
, const struct sk_buff
*skb
)
848 /* All ethernet/IP/TCP headers combined size is TCP header size
849 * plus offset of TCP header relative to start of packet.
851 st
->header_len
= ((tcp_hdr(skb
)->doff
<< 2u)
852 + PTR_DIFF(tcp_hdr(skb
), skb
->data
));
853 st
->full_packet_size
= st
->header_len
+ skb_shinfo(skb
)->gso_size
;
855 st
->ipv4_id
= ntohs(ip_hdr(skb
)->id
);
856 st
->seqnum
= ntohl(tcp_hdr(skb
)->seq
);
858 EFX_BUG_ON_PARANOID(tcp_hdr(skb
)->urg
);
859 EFX_BUG_ON_PARANOID(tcp_hdr(skb
)->syn
);
860 EFX_BUG_ON_PARANOID(tcp_hdr(skb
)->rst
);
862 st
->packet_space
= st
->full_packet_size
;
863 st
->out_len
= skb
->len
- st
->header_len
;
865 st
->unmap_single
= false;
868 static int tso_get_fragment(struct tso_state
*st
, struct efx_nic
*efx
,
871 st
->unmap_addr
= pci_map_page(efx
->pci_dev
, frag
->page
,
872 frag
->page_offset
, frag
->size
,
874 if (likely(!pci_dma_mapping_error(efx
->pci_dev
, st
->unmap_addr
))) {
875 st
->unmap_single
= false;
876 st
->unmap_len
= frag
->size
;
877 st
->in_len
= frag
->size
;
878 st
->dma_addr
= st
->unmap_addr
;
884 static int tso_get_head_fragment(struct tso_state
*st
, struct efx_nic
*efx
,
885 const struct sk_buff
*skb
)
887 int hl
= st
->header_len
;
888 int len
= skb_headlen(skb
) - hl
;
890 st
->unmap_addr
= pci_map_single(efx
->pci_dev
, skb
->data
+ hl
,
891 len
, PCI_DMA_TODEVICE
);
892 if (likely(!pci_dma_mapping_error(efx
->pci_dev
, st
->unmap_addr
))) {
893 st
->unmap_single
= true;
896 st
->dma_addr
= st
->unmap_addr
;
904 * tso_fill_packet_with_fragment - form descriptors for the current fragment
905 * @tx_queue: Efx TX queue
906 * @skb: Socket buffer
909 * Form descriptors for the current fragment, until we reach the end
910 * of fragment or end-of-packet. Return 0 on success, 1 if not enough
911 * space in @tx_queue.
913 static int tso_fill_packet_with_fragment(struct efx_tx_queue
*tx_queue
,
914 const struct sk_buff
*skb
,
915 struct tso_state
*st
)
917 struct efx_tx_buffer
*buffer
;
918 int n
, end_of_packet
, rc
;
922 if (st
->packet_space
== 0)
925 EFX_BUG_ON_PARANOID(st
->in_len
<= 0);
926 EFX_BUG_ON_PARANOID(st
->packet_space
<= 0);
928 n
= min(st
->in_len
, st
->packet_space
);
930 st
->packet_space
-= n
;
934 rc
= efx_tx_queue_insert(tx_queue
, st
->dma_addr
, n
, &buffer
);
935 if (likely(rc
== 0)) {
936 if (st
->out_len
== 0)
937 /* Transfer ownership of the skb */
940 end_of_packet
= st
->out_len
== 0 || st
->packet_space
== 0;
941 buffer
->continuation
= !end_of_packet
;
943 if (st
->in_len
== 0) {
944 /* Transfer ownership of the pci mapping */
945 buffer
->unmap_len
= st
->unmap_len
;
946 buffer
->unmap_single
= st
->unmap_single
;
957 * tso_start_new_packet - generate a new header and prepare for the new packet
958 * @tx_queue: Efx TX queue
959 * @skb: Socket buffer
962 * Generate a new header and prepare for the new packet. Return 0 on
963 * success, or -1 if failed to alloc header.
965 static int tso_start_new_packet(struct efx_tx_queue
*tx_queue
,
966 const struct sk_buff
*skb
,
967 struct tso_state
*st
)
969 struct efx_tso_header
*tsoh
;
970 struct iphdr
*tsoh_iph
;
971 struct tcphdr
*tsoh_th
;
975 /* Allocate a DMA-mapped header buffer. */
976 if (likely(TSOH_SIZE(st
->header_len
) <= TSOH_STD_SIZE
)) {
977 if (tx_queue
->tso_headers_free
== NULL
) {
978 if (efx_tsoh_block_alloc(tx_queue
))
981 EFX_BUG_ON_PARANOID(!tx_queue
->tso_headers_free
);
982 tsoh
= tx_queue
->tso_headers_free
;
983 tx_queue
->tso_headers_free
= tsoh
->next
;
986 tx_queue
->tso_long_headers
++;
987 tsoh
= efx_tsoh_heap_alloc(tx_queue
, st
->header_len
);
992 header
= TSOH_BUFFER(tsoh
);
993 tsoh_th
= (struct tcphdr
*)(header
+ SKB_TCP_OFF(skb
));
994 tsoh_iph
= (struct iphdr
*)(header
+ SKB_IPV4_OFF(skb
));
996 /* Copy and update the headers. */
997 memcpy(header
, skb
->data
, st
->header_len
);
999 tsoh_th
->seq
= htonl(st
->seqnum
);
1000 st
->seqnum
+= skb_shinfo(skb
)->gso_size
;
1001 if (st
->out_len
> skb_shinfo(skb
)->gso_size
) {
1002 /* This packet will not finish the TSO burst. */
1003 ip_length
= st
->full_packet_size
- ETH_HDR_LEN(skb
);
1007 /* This packet will be the last in the TSO burst. */
1008 ip_length
= st
->header_len
- ETH_HDR_LEN(skb
) + st
->out_len
;
1009 tsoh_th
->fin
= tcp_hdr(skb
)->fin
;
1010 tsoh_th
->psh
= tcp_hdr(skb
)->psh
;
1012 tsoh_iph
->tot_len
= htons(ip_length
);
1014 /* Linux leaves suitable gaps in the IP ID space for us to fill. */
1015 tsoh_iph
->id
= htons(st
->ipv4_id
);
1018 st
->packet_space
= skb_shinfo(skb
)->gso_size
;
1019 ++tx_queue
->tso_packets
;
1021 /* Form a descriptor for this header. */
1022 efx_tso_put_header(tx_queue
, tsoh
, st
->header_len
);
1029 * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer
1030 * @tx_queue: Efx TX queue
1031 * @skb: Socket buffer
1033 * Context: You must hold netif_tx_lock() to call this function.
1035 * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if
1036 * @skb was not enqueued. In all cases @skb is consumed. Return
1037 * %NETDEV_TX_OK or %NETDEV_TX_BUSY.
1039 static int efx_enqueue_skb_tso(struct efx_tx_queue
*tx_queue
,
1040 struct sk_buff
*skb
)
1042 struct efx_nic
*efx
= tx_queue
->efx
;
1043 int frag_i
, rc
, rc2
= NETDEV_TX_OK
;
1044 struct tso_state state
;
1046 /* Verify TSO is safe - these checks should never fail. */
1047 efx_tso_check_safe(skb
);
1049 EFX_BUG_ON_PARANOID(tx_queue
->write_count
!= tx_queue
->insert_count
);
1051 tso_start(&state
, skb
);
1053 /* Assume that skb header area contains exactly the headers, and
1054 * all payload is in the frag list.
1056 if (skb_headlen(skb
) == state
.header_len
) {
1057 /* Grab the first payload fragment. */
1058 EFX_BUG_ON_PARANOID(skb_shinfo(skb
)->nr_frags
< 1);
1060 rc
= tso_get_fragment(&state
, efx
,
1061 skb_shinfo(skb
)->frags
+ frag_i
);
1065 rc
= tso_get_head_fragment(&state
, efx
, skb
);
1071 if (tso_start_new_packet(tx_queue
, skb
, &state
) < 0)
1075 rc
= tso_fill_packet_with_fragment(tx_queue
, skb
, &state
);
1079 /* Move onto the next fragment? */
1080 if (state
.in_len
== 0) {
1081 if (++frag_i
>= skb_shinfo(skb
)->nr_frags
)
1082 /* End of payload reached. */
1084 rc
= tso_get_fragment(&state
, efx
,
1085 skb_shinfo(skb
)->frags
+ frag_i
);
1090 /* Start at new packet? */
1091 if (state
.packet_space
== 0 &&
1092 tso_start_new_packet(tx_queue
, skb
, &state
) < 0)
1096 /* Pass off to hardware */
1097 falcon_push_buffers(tx_queue
);
1099 tx_queue
->tso_bursts
++;
1100 return NETDEV_TX_OK
;
1103 EFX_ERR(efx
, "Out of memory for TSO headers, or PCI mapping error\n");
1104 dev_kfree_skb_any((struct sk_buff
*)skb
);
1108 rc2
= NETDEV_TX_BUSY
;
1110 /* Stop the queue if it wasn't stopped before. */
1111 if (tx_queue
->stopped
== 1)
1112 efx_stop_queue(efx
);
1115 /* Free the DMA mapping we were in the process of writing out */
1116 if (state
.unmap_len
) {
1117 if (state
.unmap_single
)
1118 pci_unmap_single(efx
->pci_dev
, state
.unmap_addr
,
1119 state
.unmap_len
, PCI_DMA_TODEVICE
);
1121 pci_unmap_page(efx
->pci_dev
, state
.unmap_addr
,
1122 state
.unmap_len
, PCI_DMA_TODEVICE
);
1125 efx_enqueue_unwind(tx_queue
);
1131 * Free up all TSO datastructures associated with tx_queue. This
1132 * routine should be called only once the tx_queue is both empty and
1133 * will no longer be used.
1135 static void efx_fini_tso(struct efx_tx_queue
*tx_queue
)
1139 if (tx_queue
->buffer
) {
1140 for (i
= 0; i
<= tx_queue
->efx
->type
->txd_ring_mask
; ++i
)
1141 efx_tsoh_free(tx_queue
, &tx_queue
->buffer
[i
]);
1144 while (tx_queue
->tso_headers_free
!= NULL
)
1145 efx_tsoh_block_free(tx_queue
, tx_queue
->tso_headers_free
,
1146 tx_queue
->efx
->pci_dev
);