]>
Commit | Line | Data |
---|---|---|
8ceee660 BH |
1 | /**************************************************************************** |
2 | * Driver for Solarflare Solarstorm network controllers and boards | |
3 | * Copyright 2005-2006 Fen Systems Ltd. | |
4 | * Copyright 2005-2008 Solarflare Communications Inc. | |
5 | * | |
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. | |
9 | */ | |
10 | ||
11 | #include <linux/pci.h> | |
12 | #include <linux/tcp.h> | |
13 | #include <linux/ip.h> | |
14 | #include <linux/in.h> | |
15 | #include <linux/if_ether.h> | |
16 | #include <linux/highmem.h> | |
17 | #include "net_driver.h" | |
18 | #include "tx.h" | |
19 | #include "efx.h" | |
20 | #include "falcon.h" | |
21 | #include "workarounds.h" | |
22 | ||
23 | /* | |
24 | * TX descriptor ring full threshold | |
25 | * | |
26 | * The tx_queue descriptor ring fill-level must fall below this value | |
27 | * before we restart the netif queue | |
28 | */ | |
29 | #define EFX_NETDEV_TX_THRESHOLD(_tx_queue) \ | |
30 | (_tx_queue->efx->type->txd_ring_mask / 2u) | |
31 | ||
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. | |
34 | */ | |
35 | void efx_stop_queue(struct efx_nic *efx) | |
36 | { | |
37 | spin_lock_bh(&efx->netif_stop_lock); | |
38 | EFX_TRACE(efx, "stop TX queue\n"); | |
39 | ||
40 | atomic_inc(&efx->netif_stop_count); | |
41 | netif_stop_queue(efx->net_dev); | |
42 | ||
43 | spin_unlock_bh(&efx->netif_stop_lock); | |
44 | } | |
45 | ||
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. | |
49 | */ | |
4d566063 | 50 | void efx_wake_queue(struct efx_nic *efx) |
8ceee660 BH |
51 | { |
52 | local_bh_disable(); | |
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); | |
58 | } | |
59 | local_bh_enable(); | |
60 | } | |
61 | ||
4d566063 BH |
62 | static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue, |
63 | struct efx_tx_buffer *buffer) | |
8ceee660 BH |
64 | { |
65 | if (buffer->unmap_len) { | |
66 | struct pci_dev *pci_dev = tx_queue->efx->pci_dev; | |
cc12dac2 BH |
67 | dma_addr_t unmap_addr = (buffer->dma_addr + buffer->len - |
68 | buffer->unmap_len); | |
8ceee660 | 69 | if (buffer->unmap_single) |
cc12dac2 BH |
70 | pci_unmap_single(pci_dev, unmap_addr, buffer->unmap_len, |
71 | PCI_DMA_TODEVICE); | |
8ceee660 | 72 | else |
cc12dac2 BH |
73 | pci_unmap_page(pci_dev, unmap_addr, buffer->unmap_len, |
74 | PCI_DMA_TODEVICE); | |
8ceee660 | 75 | buffer->unmap_len = 0; |
dc8cfa55 | 76 | buffer->unmap_single = false; |
8ceee660 BH |
77 | } |
78 | ||
79 | if (buffer->skb) { | |
80 | dev_kfree_skb_any((struct sk_buff *) buffer->skb); | |
81 | buffer->skb = NULL; | |
82 | EFX_TRACE(tx_queue->efx, "TX queue %d transmission id %x " | |
83 | "complete\n", tx_queue->queue, read_ptr); | |
84 | } | |
85 | } | |
86 | ||
b9b39b62 BH |
87 | /** |
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. | |
93 | * | |
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. | |
98 | */ | |
99 | struct efx_tso_header { | |
100 | union { | |
101 | struct efx_tso_header *next; | |
102 | size_t unmap_len; | |
103 | }; | |
104 | dma_addr_t dma_addr; | |
105 | }; | |
106 | ||
107 | static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, | |
108 | const 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); | |
112 | ||
4d566063 BH |
113 | static void efx_tsoh_free(struct efx_tx_queue *tx_queue, |
114 | struct efx_tx_buffer *buffer) | |
b9b39b62 BH |
115 | { |
116 | if (buffer->tsoh) { | |
117 | if (likely(!buffer->tsoh->unmap_len)) { | |
118 | buffer->tsoh->next = tx_queue->tso_headers_free; | |
119 | tx_queue->tso_headers_free = buffer->tsoh; | |
120 | } else { | |
121 | efx_tsoh_heap_free(tx_queue, buffer->tsoh); | |
122 | } | |
123 | buffer->tsoh = NULL; | |
124 | } | |
125 | } | |
126 | ||
8ceee660 BH |
127 | |
128 | /* | |
129 | * Add a socket buffer to a TX queue | |
130 | * | |
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. | |
134 | * | |
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. | |
137 | * | |
138 | * Returns NETDEV_TX_OK or NETDEV_TX_BUSY | |
139 | * You must hold netif_tx_lock() to call this function. | |
140 | */ | |
4d566063 BH |
141 | static int efx_enqueue_skb(struct efx_tx_queue *tx_queue, |
142 | const struct sk_buff *skb) | |
8ceee660 BH |
143 | { |
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; | |
148 | struct page *page; | |
149 | int page_offset; | |
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; | |
dc8cfa55 | 153 | bool unmap_single; |
8ceee660 BH |
154 | int q_space, i = 0; |
155 | int rc = NETDEV_TX_OK; | |
156 | ||
157 | EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); | |
158 | ||
b9b39b62 BH |
159 | if (skb_shinfo((struct sk_buff *)skb)->gso_size) |
160 | return efx_enqueue_skb_tso(tx_queue, skb); | |
161 | ||
8ceee660 BH |
162 | /* Get size of the initial fragment */ |
163 | len = skb_headlen(skb); | |
164 | ||
165 | fill_level = tx_queue->insert_count - tx_queue->old_read_count; | |
166 | q_space = efx->type->txd_ring_mask - 1 - fill_level; | |
167 | ||
168 | /* Map for DMA. Use pci_map_single rather than pci_map_page | |
169 | * since this is more efficient on machines with sparse | |
170 | * memory. | |
171 | */ | |
dc8cfa55 | 172 | unmap_single = true; |
8ceee660 BH |
173 | dma_addr = pci_map_single(pci_dev, skb->data, len, PCI_DMA_TODEVICE); |
174 | ||
175 | /* Process all fragments */ | |
176 | while (1) { | |
8d8bb39b | 177 | if (unlikely(pci_dma_mapping_error(pci_dev, dma_addr))) |
8ceee660 BH |
178 | goto pci_err; |
179 | ||
180 | /* Store fields for marking in the per-fragment final | |
181 | * descriptor */ | |
182 | unmap_len = len; | |
183 | unmap_addr = dma_addr; | |
184 | ||
185 | /* Add to TX queue, splitting across DMA boundaries */ | |
186 | do { | |
187 | if (unlikely(q_space-- <= 0)) { | |
188 | /* It might be that completions have | |
189 | * happened since the xmit path last | |
190 | * checked. Update the xmit path's | |
191 | * copy of read_count. | |
192 | */ | |
193 | ++tx_queue->stopped; | |
194 | /* This memory barrier protects the | |
195 | * change of stopped from the access | |
196 | * of read_count. */ | |
197 | smp_mb(); | |
198 | tx_queue->old_read_count = | |
199 | *(volatile unsigned *) | |
200 | &tx_queue->read_count; | |
201 | fill_level = (tx_queue->insert_count | |
202 | - tx_queue->old_read_count); | |
203 | q_space = (efx->type->txd_ring_mask - 1 - | |
204 | fill_level); | |
205 | if (unlikely(q_space-- <= 0)) | |
206 | goto stop; | |
207 | smp_mb(); | |
208 | --tx_queue->stopped; | |
209 | } | |
210 | ||
211 | insert_ptr = (tx_queue->insert_count & | |
212 | efx->type->txd_ring_mask); | |
213 | buffer = &tx_queue->buffer[insert_ptr]; | |
b9b39b62 BH |
214 | efx_tsoh_free(tx_queue, buffer); |
215 | EFX_BUG_ON_PARANOID(buffer->tsoh); | |
8ceee660 BH |
216 | EFX_BUG_ON_PARANOID(buffer->skb); |
217 | EFX_BUG_ON_PARANOID(buffer->len); | |
dc8cfa55 | 218 | EFX_BUG_ON_PARANOID(!buffer->continuation); |
8ceee660 BH |
219 | EFX_BUG_ON_PARANOID(buffer->unmap_len); |
220 | ||
221 | dma_len = (((~dma_addr) & efx->type->tx_dma_mask) + 1); | |
222 | if (likely(dma_len > len)) | |
223 | dma_len = len; | |
224 | ||
225 | misalign = (unsigned)dma_addr & efx->type->bug5391_mask; | |
226 | if (misalign && dma_len + misalign > 512) | |
227 | dma_len = 512 - misalign; | |
228 | ||
229 | /* Fill out per descriptor fields */ | |
230 | buffer->len = dma_len; | |
231 | buffer->dma_addr = dma_addr; | |
232 | len -= dma_len; | |
233 | dma_addr += dma_len; | |
234 | ++tx_queue->insert_count; | |
235 | } while (len); | |
236 | ||
237 | /* Transfer ownership of the unmapping to the final buffer */ | |
8ceee660 BH |
238 | buffer->unmap_single = unmap_single; |
239 | buffer->unmap_len = unmap_len; | |
240 | unmap_len = 0; | |
241 | ||
242 | /* Get address and size of next fragment */ | |
243 | if (i >= skb_shinfo(skb)->nr_frags) | |
244 | break; | |
245 | fragment = &skb_shinfo(skb)->frags[i]; | |
246 | len = fragment->size; | |
247 | page = fragment->page; | |
248 | page_offset = fragment->page_offset; | |
249 | i++; | |
250 | /* Map for DMA */ | |
dc8cfa55 | 251 | unmap_single = false; |
8ceee660 BH |
252 | dma_addr = pci_map_page(pci_dev, page, page_offset, len, |
253 | PCI_DMA_TODEVICE); | |
254 | } | |
255 | ||
256 | /* Transfer ownership of the skb to the final buffer */ | |
257 | buffer->skb = skb; | |
dc8cfa55 | 258 | buffer->continuation = false; |
8ceee660 BH |
259 | |
260 | /* Pass off to hardware */ | |
261 | falcon_push_buffers(tx_queue); | |
262 | ||
263 | return NETDEV_TX_OK; | |
264 | ||
265 | pci_err: | |
266 | EFX_ERR_RL(efx, " TX queue %d could not map skb with %d bytes %d " | |
267 | "fragments for DMA\n", tx_queue->queue, skb->len, | |
268 | skb_shinfo(skb)->nr_frags + 1); | |
269 | ||
270 | /* Mark the packet as transmitted, and free the SKB ourselves */ | |
271 | dev_kfree_skb_any((struct sk_buff *)skb); | |
272 | goto unwind; | |
273 | ||
274 | stop: | |
275 | rc = NETDEV_TX_BUSY; | |
276 | ||
277 | if (tx_queue->stopped == 1) | |
278 | efx_stop_queue(efx); | |
279 | ||
280 | unwind: | |
281 | /* Work backwards until we hit the original insert pointer value */ | |
282 | while (tx_queue->insert_count != tx_queue->write_count) { | |
283 | --tx_queue->insert_count; | |
284 | insert_ptr = tx_queue->insert_count & efx->type->txd_ring_mask; | |
285 | buffer = &tx_queue->buffer[insert_ptr]; | |
286 | efx_dequeue_buffer(tx_queue, buffer); | |
287 | buffer->len = 0; | |
288 | } | |
289 | ||
290 | /* Free the fragment we were mid-way through pushing */ | |
ecbd95c1 BH |
291 | if (unmap_len) { |
292 | if (unmap_single) | |
293 | pci_unmap_single(pci_dev, unmap_addr, unmap_len, | |
294 | PCI_DMA_TODEVICE); | |
295 | else | |
296 | pci_unmap_page(pci_dev, unmap_addr, unmap_len, | |
297 | PCI_DMA_TODEVICE); | |
298 | } | |
8ceee660 BH |
299 | |
300 | return rc; | |
301 | } | |
302 | ||
303 | /* Remove packets from the TX queue | |
304 | * | |
305 | * This removes packets from the TX queue, up to and including the | |
306 | * specified index. | |
307 | */ | |
4d566063 BH |
308 | static void efx_dequeue_buffers(struct efx_tx_queue *tx_queue, |
309 | unsigned int index) | |
8ceee660 BH |
310 | { |
311 | struct efx_nic *efx = tx_queue->efx; | |
312 | unsigned int stop_index, read_ptr; | |
313 | unsigned int mask = tx_queue->efx->type->txd_ring_mask; | |
314 | ||
315 | stop_index = (index + 1) & mask; | |
316 | read_ptr = tx_queue->read_count & mask; | |
317 | ||
318 | while (read_ptr != stop_index) { | |
319 | struct efx_tx_buffer *buffer = &tx_queue->buffer[read_ptr]; | |
320 | if (unlikely(buffer->len == 0)) { | |
321 | EFX_ERR(tx_queue->efx, "TX queue %d spurious TX " | |
322 | "completion id %x\n", tx_queue->queue, | |
323 | read_ptr); | |
324 | efx_schedule_reset(efx, RESET_TYPE_TX_SKIP); | |
325 | return; | |
326 | } | |
327 | ||
328 | efx_dequeue_buffer(tx_queue, buffer); | |
dc8cfa55 | 329 | buffer->continuation = true; |
8ceee660 BH |
330 | buffer->len = 0; |
331 | ||
332 | ++tx_queue->read_count; | |
333 | read_ptr = tx_queue->read_count & mask; | |
334 | } | |
335 | } | |
336 | ||
337 | /* Initiate a packet transmission on the specified TX queue. | |
338 | * Note that returning anything other than NETDEV_TX_OK will cause the | |
339 | * OS to free the skb. | |
340 | * | |
341 | * This function is split out from efx_hard_start_xmit to allow the | |
342 | * loopback test to direct packets via specific TX queues. It is | |
343 | * therefore a non-static inline, so as not to penalise performance | |
344 | * for non-loopback transmissions. | |
345 | * | |
346 | * Context: netif_tx_lock held | |
347 | */ | |
348 | inline int efx_xmit(struct efx_nic *efx, | |
349 | struct efx_tx_queue *tx_queue, struct sk_buff *skb) | |
350 | { | |
351 | int rc; | |
352 | ||
353 | /* Map fragments for DMA and add to TX queue */ | |
354 | rc = efx_enqueue_skb(tx_queue, skb); | |
355 | if (unlikely(rc != NETDEV_TX_OK)) | |
356 | goto out; | |
357 | ||
358 | /* Update last TX timer */ | |
359 | efx->net_dev->trans_start = jiffies; | |
360 | ||
361 | out: | |
362 | return rc; | |
363 | } | |
364 | ||
365 | /* Initiate a packet transmission. We use one channel per CPU | |
366 | * (sharing when we have more CPUs than channels). On Falcon, the TX | |
367 | * completion events will be directed back to the CPU that transmitted | |
368 | * the packet, which should be cache-efficient. | |
369 | * | |
370 | * Context: non-blocking. | |
371 | * Note that returning anything other than NETDEV_TX_OK will cause the | |
372 | * OS to free the skb. | |
373 | */ | |
374 | int efx_hard_start_xmit(struct sk_buff *skb, struct net_device *net_dev) | |
375 | { | |
767e468c | 376 | struct efx_nic *efx = netdev_priv(net_dev); |
60ac1065 BH |
377 | struct efx_tx_queue *tx_queue; |
378 | ||
379 | if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) | |
380 | tx_queue = &efx->tx_queue[EFX_TX_QUEUE_OFFLOAD_CSUM]; | |
381 | else | |
382 | tx_queue = &efx->tx_queue[EFX_TX_QUEUE_NO_CSUM]; | |
383 | ||
384 | return efx_xmit(efx, tx_queue, skb); | |
8ceee660 BH |
385 | } |
386 | ||
387 | void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index) | |
388 | { | |
389 | unsigned fill_level; | |
390 | struct efx_nic *efx = tx_queue->efx; | |
391 | ||
392 | EFX_BUG_ON_PARANOID(index > efx->type->txd_ring_mask); | |
393 | ||
394 | efx_dequeue_buffers(tx_queue, index); | |
395 | ||
396 | /* See if we need to restart the netif queue. This barrier | |
397 | * separates the update of read_count from the test of | |
398 | * stopped. */ | |
399 | smp_mb(); | |
400 | if (unlikely(tx_queue->stopped)) { | |
401 | fill_level = tx_queue->insert_count - tx_queue->read_count; | |
402 | if (fill_level < EFX_NETDEV_TX_THRESHOLD(tx_queue)) { | |
55668611 | 403 | EFX_BUG_ON_PARANOID(!efx_dev_registered(efx)); |
8ceee660 BH |
404 | |
405 | /* Do this under netif_tx_lock(), to avoid racing | |
406 | * with efx_xmit(). */ | |
407 | netif_tx_lock(efx->net_dev); | |
408 | if (tx_queue->stopped) { | |
409 | tx_queue->stopped = 0; | |
410 | efx_wake_queue(efx); | |
411 | } | |
412 | netif_tx_unlock(efx->net_dev); | |
413 | } | |
414 | } | |
415 | } | |
416 | ||
417 | int efx_probe_tx_queue(struct efx_tx_queue *tx_queue) | |
418 | { | |
419 | struct efx_nic *efx = tx_queue->efx; | |
420 | unsigned int txq_size; | |
421 | int i, rc; | |
422 | ||
423 | EFX_LOG(efx, "creating TX queue %d\n", tx_queue->queue); | |
424 | ||
425 | /* Allocate software ring */ | |
426 | txq_size = (efx->type->txd_ring_mask + 1) * sizeof(*tx_queue->buffer); | |
427 | tx_queue->buffer = kzalloc(txq_size, GFP_KERNEL); | |
60ac1065 BH |
428 | if (!tx_queue->buffer) |
429 | return -ENOMEM; | |
8ceee660 | 430 | for (i = 0; i <= efx->type->txd_ring_mask; ++i) |
dc8cfa55 | 431 | tx_queue->buffer[i].continuation = true; |
8ceee660 BH |
432 | |
433 | /* Allocate hardware ring */ | |
434 | rc = falcon_probe_tx(tx_queue); | |
435 | if (rc) | |
60ac1065 | 436 | goto fail; |
8ceee660 BH |
437 | |
438 | return 0; | |
439 | ||
60ac1065 | 440 | fail: |
8ceee660 BH |
441 | kfree(tx_queue->buffer); |
442 | tx_queue->buffer = NULL; | |
8ceee660 BH |
443 | return rc; |
444 | } | |
445 | ||
446 | int efx_init_tx_queue(struct efx_tx_queue *tx_queue) | |
447 | { | |
448 | EFX_LOG(tx_queue->efx, "initialising TX queue %d\n", tx_queue->queue); | |
449 | ||
450 | tx_queue->insert_count = 0; | |
451 | tx_queue->write_count = 0; | |
452 | tx_queue->read_count = 0; | |
453 | tx_queue->old_read_count = 0; | |
454 | BUG_ON(tx_queue->stopped); | |
455 | ||
456 | /* Set up TX descriptor ring */ | |
457 | return falcon_init_tx(tx_queue); | |
458 | } | |
459 | ||
460 | void efx_release_tx_buffers(struct efx_tx_queue *tx_queue) | |
461 | { | |
462 | struct efx_tx_buffer *buffer; | |
463 | ||
464 | if (!tx_queue->buffer) | |
465 | return; | |
466 | ||
467 | /* Free any buffers left in the ring */ | |
468 | while (tx_queue->read_count != tx_queue->write_count) { | |
469 | buffer = &tx_queue->buffer[tx_queue->read_count & | |
470 | tx_queue->efx->type->txd_ring_mask]; | |
471 | efx_dequeue_buffer(tx_queue, buffer); | |
dc8cfa55 | 472 | buffer->continuation = true; |
8ceee660 BH |
473 | buffer->len = 0; |
474 | ||
475 | ++tx_queue->read_count; | |
476 | } | |
477 | } | |
478 | ||
479 | void efx_fini_tx_queue(struct efx_tx_queue *tx_queue) | |
480 | { | |
481 | EFX_LOG(tx_queue->efx, "shutting down TX queue %d\n", tx_queue->queue); | |
482 | ||
483 | /* Flush TX queue, remove descriptor ring */ | |
484 | falcon_fini_tx(tx_queue); | |
485 | ||
486 | efx_release_tx_buffers(tx_queue); | |
487 | ||
b9b39b62 BH |
488 | /* Free up TSO header cache */ |
489 | efx_fini_tso(tx_queue); | |
490 | ||
8ceee660 BH |
491 | /* Release queue's stop on port, if any */ |
492 | if (tx_queue->stopped) { | |
493 | tx_queue->stopped = 0; | |
494 | efx_wake_queue(tx_queue->efx); | |
495 | } | |
496 | } | |
497 | ||
498 | void efx_remove_tx_queue(struct efx_tx_queue *tx_queue) | |
499 | { | |
500 | EFX_LOG(tx_queue->efx, "destroying TX queue %d\n", tx_queue->queue); | |
501 | falcon_remove_tx(tx_queue); | |
502 | ||
503 | kfree(tx_queue->buffer); | |
504 | tx_queue->buffer = NULL; | |
8ceee660 BH |
505 | } |
506 | ||
507 | ||
b9b39b62 BH |
508 | /* Efx TCP segmentation acceleration. |
509 | * | |
510 | * Why? Because by doing it here in the driver we can go significantly | |
511 | * faster than the GSO. | |
512 | * | |
513 | * Requires TX checksum offload support. | |
514 | */ | |
515 | ||
516 | /* Number of bytes inserted at the start of a TSO header buffer, | |
517 | * similar to NET_IP_ALIGN. | |
518 | */ | |
519 | #if defined(__i386__) || defined(__x86_64__) | |
520 | #define TSOH_OFFSET 0 | |
521 | #else | |
522 | #define TSOH_OFFSET NET_IP_ALIGN | |
523 | #endif | |
524 | ||
525 | #define TSOH_BUFFER(tsoh) ((u8 *)(tsoh + 1) + TSOH_OFFSET) | |
526 | ||
527 | /* Total size of struct efx_tso_header, buffer and padding */ | |
528 | #define TSOH_SIZE(hdr_len) \ | |
529 | (sizeof(struct efx_tso_header) + TSOH_OFFSET + hdr_len) | |
530 | ||
531 | /* Size of blocks on free list. Larger blocks must be allocated from | |
532 | * the heap. | |
533 | */ | |
534 | #define TSOH_STD_SIZE 128 | |
535 | ||
536 | #define PTR_DIFF(p1, p2) ((u8 *)(p1) - (u8 *)(p2)) | |
537 | #define ETH_HDR_LEN(skb) (skb_network_header(skb) - (skb)->data) | |
538 | #define SKB_TCP_OFF(skb) PTR_DIFF(tcp_hdr(skb), (skb)->data) | |
539 | #define SKB_IPV4_OFF(skb) PTR_DIFF(ip_hdr(skb), (skb)->data) | |
540 | ||
541 | /** | |
542 | * struct tso_state - TSO state for an SKB | |
23d9e60b | 543 | * @out_len: Remaining length in current segment |
b9b39b62 | 544 | * @seqnum: Current sequence number |
23d9e60b | 545 | * @ipv4_id: Current IPv4 ID, host endian |
b9b39b62 | 546 | * @packet_space: Remaining space in current packet |
23d9e60b BH |
547 | * @dma_addr: DMA address of current position |
548 | * @in_len: Remaining length in current SKB fragment | |
549 | * @unmap_len: Length of SKB fragment | |
550 | * @unmap_addr: DMA address of SKB fragment | |
551 | * @unmap_single: DMA single vs page mapping flag | |
552 | * @header_len: Number of bytes of header | |
553 | * @full_packet_size: Number of bytes to put in each outgoing segment | |
b9b39b62 BH |
554 | * |
555 | * The state used during segmentation. It is put into this data structure | |
556 | * just to make it easy to pass into inline functions. | |
557 | */ | |
558 | struct tso_state { | |
23d9e60b BH |
559 | /* Output position */ |
560 | unsigned out_len; | |
b9b39b62 | 561 | unsigned seqnum; |
23d9e60b | 562 | unsigned ipv4_id; |
b9b39b62 BH |
563 | unsigned packet_space; |
564 | ||
23d9e60b BH |
565 | /* Input position */ |
566 | dma_addr_t dma_addr; | |
567 | unsigned in_len; | |
568 | unsigned unmap_len; | |
569 | dma_addr_t unmap_addr; | |
570 | bool unmap_single; | |
571 | ||
572 | unsigned header_len; | |
573 | int full_packet_size; | |
b9b39b62 BH |
574 | }; |
575 | ||
576 | ||
577 | /* | |
578 | * Verify that our various assumptions about sk_buffs and the conditions | |
579 | * under which TSO will be attempted hold true. | |
580 | */ | |
4d566063 | 581 | static void efx_tso_check_safe(const struct sk_buff *skb) |
b9b39b62 BH |
582 | { |
583 | EFX_BUG_ON_PARANOID(skb->protocol != htons(ETH_P_IP)); | |
584 | EFX_BUG_ON_PARANOID(((struct ethhdr *)skb->data)->h_proto != | |
585 | skb->protocol); | |
586 | EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP); | |
587 | EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb), skb->data) | |
588 | + (tcp_hdr(skb)->doff << 2u)) > | |
589 | skb_headlen(skb)); | |
590 | } | |
591 | ||
592 | ||
593 | /* | |
594 | * Allocate a page worth of efx_tso_header structures, and string them | |
595 | * into the tx_queue->tso_headers_free linked list. Return 0 or -ENOMEM. | |
596 | */ | |
597 | static int efx_tsoh_block_alloc(struct efx_tx_queue *tx_queue) | |
598 | { | |
599 | ||
600 | struct pci_dev *pci_dev = tx_queue->efx->pci_dev; | |
601 | struct efx_tso_header *tsoh; | |
602 | dma_addr_t dma_addr; | |
603 | u8 *base_kva, *kva; | |
604 | ||
605 | base_kva = pci_alloc_consistent(pci_dev, PAGE_SIZE, &dma_addr); | |
606 | if (base_kva == NULL) { | |
607 | EFX_ERR(tx_queue->efx, "Unable to allocate page for TSO" | |
608 | " headers\n"); | |
609 | return -ENOMEM; | |
610 | } | |
611 | ||
612 | /* pci_alloc_consistent() allocates pages. */ | |
613 | EFX_BUG_ON_PARANOID(dma_addr & (PAGE_SIZE - 1u)); | |
614 | ||
615 | for (kva = base_kva; kva < base_kva + PAGE_SIZE; kva += TSOH_STD_SIZE) { | |
616 | tsoh = (struct efx_tso_header *)kva; | |
617 | tsoh->dma_addr = dma_addr + (TSOH_BUFFER(tsoh) - base_kva); | |
618 | tsoh->next = tx_queue->tso_headers_free; | |
619 | tx_queue->tso_headers_free = tsoh; | |
620 | } | |
621 | ||
622 | return 0; | |
623 | } | |
624 | ||
625 | ||
626 | /* Free up a TSO header, and all others in the same page. */ | |
627 | static void efx_tsoh_block_free(struct efx_tx_queue *tx_queue, | |
628 | struct efx_tso_header *tsoh, | |
629 | struct pci_dev *pci_dev) | |
630 | { | |
631 | struct efx_tso_header **p; | |
632 | unsigned long base_kva; | |
633 | dma_addr_t base_dma; | |
634 | ||
635 | base_kva = (unsigned long)tsoh & PAGE_MASK; | |
636 | base_dma = tsoh->dma_addr & PAGE_MASK; | |
637 | ||
638 | p = &tx_queue->tso_headers_free; | |
b3475645 | 639 | while (*p != NULL) { |
b9b39b62 BH |
640 | if (((unsigned long)*p & PAGE_MASK) == base_kva) |
641 | *p = (*p)->next; | |
642 | else | |
643 | p = &(*p)->next; | |
b3475645 | 644 | } |
b9b39b62 BH |
645 | |
646 | pci_free_consistent(pci_dev, PAGE_SIZE, (void *)base_kva, base_dma); | |
647 | } | |
648 | ||
649 | static struct efx_tso_header * | |
650 | efx_tsoh_heap_alloc(struct efx_tx_queue *tx_queue, size_t header_len) | |
651 | { | |
652 | struct efx_tso_header *tsoh; | |
653 | ||
654 | tsoh = kmalloc(TSOH_SIZE(header_len), GFP_ATOMIC | GFP_DMA); | |
655 | if (unlikely(!tsoh)) | |
656 | return NULL; | |
657 | ||
658 | tsoh->dma_addr = pci_map_single(tx_queue->efx->pci_dev, | |
659 | TSOH_BUFFER(tsoh), header_len, | |
660 | PCI_DMA_TODEVICE); | |
8d8bb39b FT |
661 | if (unlikely(pci_dma_mapping_error(tx_queue->efx->pci_dev, |
662 | tsoh->dma_addr))) { | |
b9b39b62 BH |
663 | kfree(tsoh); |
664 | return NULL; | |
665 | } | |
666 | ||
667 | tsoh->unmap_len = header_len; | |
668 | return tsoh; | |
669 | } | |
670 | ||
671 | static void | |
672 | efx_tsoh_heap_free(struct efx_tx_queue *tx_queue, struct efx_tso_header *tsoh) | |
673 | { | |
674 | pci_unmap_single(tx_queue->efx->pci_dev, | |
675 | tsoh->dma_addr, tsoh->unmap_len, | |
676 | PCI_DMA_TODEVICE); | |
677 | kfree(tsoh); | |
678 | } | |
679 | ||
680 | /** | |
681 | * efx_tx_queue_insert - push descriptors onto the TX queue | |
682 | * @tx_queue: Efx TX queue | |
683 | * @dma_addr: DMA address of fragment | |
684 | * @len: Length of fragment | |
ecbd95c1 | 685 | * @final_buffer: The final buffer inserted into the queue |
b9b39b62 BH |
686 | * |
687 | * Push descriptors onto the TX queue. Return 0 on success or 1 if | |
688 | * @tx_queue full. | |
689 | */ | |
690 | static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue, | |
691 | dma_addr_t dma_addr, unsigned len, | |
ecbd95c1 | 692 | struct efx_tx_buffer **final_buffer) |
b9b39b62 BH |
693 | { |
694 | struct efx_tx_buffer *buffer; | |
695 | struct efx_nic *efx = tx_queue->efx; | |
696 | unsigned dma_len, fill_level, insert_ptr, misalign; | |
697 | int q_space; | |
698 | ||
699 | EFX_BUG_ON_PARANOID(len <= 0); | |
700 | ||
701 | fill_level = tx_queue->insert_count - tx_queue->old_read_count; | |
702 | /* -1 as there is no way to represent all descriptors used */ | |
703 | q_space = efx->type->txd_ring_mask - 1 - fill_level; | |
704 | ||
705 | while (1) { | |
706 | if (unlikely(q_space-- <= 0)) { | |
707 | /* It might be that completions have happened | |
708 | * since the xmit path last checked. Update | |
709 | * the xmit path's copy of read_count. | |
710 | */ | |
711 | ++tx_queue->stopped; | |
712 | /* This memory barrier protects the change of | |
713 | * stopped from the access of read_count. */ | |
714 | smp_mb(); | |
715 | tx_queue->old_read_count = | |
716 | *(volatile unsigned *)&tx_queue->read_count; | |
717 | fill_level = (tx_queue->insert_count | |
718 | - tx_queue->old_read_count); | |
719 | q_space = efx->type->txd_ring_mask - 1 - fill_level; | |
ecbd95c1 BH |
720 | if (unlikely(q_space-- <= 0)) { |
721 | *final_buffer = NULL; | |
b9b39b62 | 722 | return 1; |
ecbd95c1 | 723 | } |
b9b39b62 BH |
724 | smp_mb(); |
725 | --tx_queue->stopped; | |
726 | } | |
727 | ||
728 | insert_ptr = tx_queue->insert_count & efx->type->txd_ring_mask; | |
729 | buffer = &tx_queue->buffer[insert_ptr]; | |
730 | ++tx_queue->insert_count; | |
731 | ||
732 | EFX_BUG_ON_PARANOID(tx_queue->insert_count - | |
733 | tx_queue->read_count > | |
734 | efx->type->txd_ring_mask); | |
735 | ||
736 | efx_tsoh_free(tx_queue, buffer); | |
737 | EFX_BUG_ON_PARANOID(buffer->len); | |
738 | EFX_BUG_ON_PARANOID(buffer->unmap_len); | |
739 | EFX_BUG_ON_PARANOID(buffer->skb); | |
dc8cfa55 | 740 | EFX_BUG_ON_PARANOID(!buffer->continuation); |
b9b39b62 BH |
741 | EFX_BUG_ON_PARANOID(buffer->tsoh); |
742 | ||
743 | buffer->dma_addr = dma_addr; | |
744 | ||
745 | /* Ensure we do not cross a boundary unsupported by H/W */ | |
746 | dma_len = (~dma_addr & efx->type->tx_dma_mask) + 1; | |
747 | ||
748 | misalign = (unsigned)dma_addr & efx->type->bug5391_mask; | |
749 | if (misalign && dma_len + misalign > 512) | |
750 | dma_len = 512 - misalign; | |
751 | ||
752 | /* If there is enough space to send then do so */ | |
753 | if (dma_len >= len) | |
754 | break; | |
755 | ||
756 | buffer->len = dma_len; /* Don't set the other members */ | |
757 | dma_addr += dma_len; | |
758 | len -= dma_len; | |
759 | } | |
760 | ||
761 | EFX_BUG_ON_PARANOID(!len); | |
762 | buffer->len = len; | |
ecbd95c1 | 763 | *final_buffer = buffer; |
b9b39b62 BH |
764 | return 0; |
765 | } | |
766 | ||
767 | ||
768 | /* | |
769 | * Put a TSO header into the TX queue. | |
770 | * | |
771 | * This is special-cased because we know that it is small enough to fit in | |
772 | * a single fragment, and we know it doesn't cross a page boundary. It | |
773 | * also allows us to not worry about end-of-packet etc. | |
774 | */ | |
4d566063 BH |
775 | static void efx_tso_put_header(struct efx_tx_queue *tx_queue, |
776 | struct efx_tso_header *tsoh, unsigned len) | |
b9b39b62 BH |
777 | { |
778 | struct efx_tx_buffer *buffer; | |
779 | ||
780 | buffer = &tx_queue->buffer[tx_queue->insert_count & | |
781 | tx_queue->efx->type->txd_ring_mask]; | |
782 | efx_tsoh_free(tx_queue, buffer); | |
783 | EFX_BUG_ON_PARANOID(buffer->len); | |
784 | EFX_BUG_ON_PARANOID(buffer->unmap_len); | |
785 | EFX_BUG_ON_PARANOID(buffer->skb); | |
dc8cfa55 | 786 | EFX_BUG_ON_PARANOID(!buffer->continuation); |
b9b39b62 BH |
787 | EFX_BUG_ON_PARANOID(buffer->tsoh); |
788 | buffer->len = len; | |
789 | buffer->dma_addr = tsoh->dma_addr; | |
790 | buffer->tsoh = tsoh; | |
791 | ||
792 | ++tx_queue->insert_count; | |
793 | } | |
794 | ||
795 | ||
796 | /* Remove descriptors put into a tx_queue. */ | |
797 | static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue) | |
798 | { | |
799 | struct efx_tx_buffer *buffer; | |
cc12dac2 | 800 | dma_addr_t unmap_addr; |
b9b39b62 BH |
801 | |
802 | /* Work backwards until we hit the original insert pointer value */ | |
803 | while (tx_queue->insert_count != tx_queue->write_count) { | |
804 | --tx_queue->insert_count; | |
805 | buffer = &tx_queue->buffer[tx_queue->insert_count & | |
806 | tx_queue->efx->type->txd_ring_mask]; | |
807 | efx_tsoh_free(tx_queue, buffer); | |
808 | EFX_BUG_ON_PARANOID(buffer->skb); | |
809 | buffer->len = 0; | |
dc8cfa55 | 810 | buffer->continuation = true; |
b9b39b62 | 811 | if (buffer->unmap_len) { |
cc12dac2 BH |
812 | unmap_addr = (buffer->dma_addr + buffer->len - |
813 | buffer->unmap_len); | |
ecbd95c1 BH |
814 | if (buffer->unmap_single) |
815 | pci_unmap_single(tx_queue->efx->pci_dev, | |
cc12dac2 | 816 | unmap_addr, buffer->unmap_len, |
ecbd95c1 BH |
817 | PCI_DMA_TODEVICE); |
818 | else | |
819 | pci_unmap_page(tx_queue->efx->pci_dev, | |
cc12dac2 | 820 | unmap_addr, buffer->unmap_len, |
ecbd95c1 | 821 | PCI_DMA_TODEVICE); |
b9b39b62 BH |
822 | buffer->unmap_len = 0; |
823 | } | |
824 | } | |
825 | } | |
826 | ||
827 | ||
828 | /* Parse the SKB header and initialise state. */ | |
4d566063 | 829 | static void tso_start(struct tso_state *st, const struct sk_buff *skb) |
b9b39b62 BH |
830 | { |
831 | /* All ethernet/IP/TCP headers combined size is TCP header size | |
832 | * plus offset of TCP header relative to start of packet. | |
833 | */ | |
23d9e60b BH |
834 | st->header_len = ((tcp_hdr(skb)->doff << 2u) |
835 | + PTR_DIFF(tcp_hdr(skb), skb->data)); | |
836 | st->full_packet_size = st->header_len + skb_shinfo(skb)->gso_size; | |
b9b39b62 | 837 | |
23d9e60b | 838 | st->ipv4_id = ntohs(ip_hdr(skb)->id); |
b9b39b62 BH |
839 | st->seqnum = ntohl(tcp_hdr(skb)->seq); |
840 | ||
841 | EFX_BUG_ON_PARANOID(tcp_hdr(skb)->urg); | |
842 | EFX_BUG_ON_PARANOID(tcp_hdr(skb)->syn); | |
843 | EFX_BUG_ON_PARANOID(tcp_hdr(skb)->rst); | |
844 | ||
23d9e60b BH |
845 | st->packet_space = st->full_packet_size; |
846 | st->out_len = skb->len - st->header_len; | |
847 | st->unmap_len = 0; | |
848 | st->unmap_single = false; | |
b9b39b62 BH |
849 | } |
850 | ||
4d566063 BH |
851 | static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx, |
852 | skb_frag_t *frag) | |
b9b39b62 | 853 | { |
23d9e60b BH |
854 | st->unmap_addr = pci_map_page(efx->pci_dev, frag->page, |
855 | frag->page_offset, frag->size, | |
856 | PCI_DMA_TODEVICE); | |
857 | if (likely(!pci_dma_mapping_error(efx->pci_dev, st->unmap_addr))) { | |
858 | st->unmap_single = false; | |
859 | st->unmap_len = frag->size; | |
860 | st->in_len = frag->size; | |
861 | st->dma_addr = st->unmap_addr; | |
ecbd95c1 BH |
862 | return 0; |
863 | } | |
864 | return -ENOMEM; | |
865 | } | |
866 | ||
4d566063 BH |
867 | static int tso_get_head_fragment(struct tso_state *st, struct efx_nic *efx, |
868 | const struct sk_buff *skb) | |
ecbd95c1 | 869 | { |
23d9e60b | 870 | int hl = st->header_len; |
ecbd95c1 | 871 | int len = skb_headlen(skb) - hl; |
b9b39b62 | 872 | |
23d9e60b BH |
873 | st->unmap_addr = pci_map_single(efx->pci_dev, skb->data + hl, |
874 | len, PCI_DMA_TODEVICE); | |
875 | if (likely(!pci_dma_mapping_error(efx->pci_dev, st->unmap_addr))) { | |
876 | st->unmap_single = true; | |
877 | st->unmap_len = len; | |
878 | st->in_len = len; | |
879 | st->dma_addr = st->unmap_addr; | |
b9b39b62 BH |
880 | return 0; |
881 | } | |
882 | return -ENOMEM; | |
883 | } | |
884 | ||
885 | ||
886 | /** | |
887 | * tso_fill_packet_with_fragment - form descriptors for the current fragment | |
888 | * @tx_queue: Efx TX queue | |
889 | * @skb: Socket buffer | |
890 | * @st: TSO state | |
891 | * | |
892 | * Form descriptors for the current fragment, until we reach the end | |
893 | * of fragment or end-of-packet. Return 0 on success, 1 if not enough | |
894 | * space in @tx_queue. | |
895 | */ | |
4d566063 BH |
896 | static int tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue, |
897 | const struct sk_buff *skb, | |
898 | struct tso_state *st) | |
b9b39b62 | 899 | { |
ecbd95c1 | 900 | struct efx_tx_buffer *buffer; |
b9b39b62 BH |
901 | int n, end_of_packet, rc; |
902 | ||
23d9e60b | 903 | if (st->in_len == 0) |
b9b39b62 BH |
904 | return 0; |
905 | if (st->packet_space == 0) | |
906 | return 0; | |
907 | ||
23d9e60b | 908 | EFX_BUG_ON_PARANOID(st->in_len <= 0); |
b9b39b62 BH |
909 | EFX_BUG_ON_PARANOID(st->packet_space <= 0); |
910 | ||
23d9e60b | 911 | n = min(st->in_len, st->packet_space); |
b9b39b62 BH |
912 | |
913 | st->packet_space -= n; | |
23d9e60b BH |
914 | st->out_len -= n; |
915 | st->in_len -= n; | |
b9b39b62 | 916 | |
23d9e60b | 917 | rc = efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer); |
ecbd95c1 | 918 | if (likely(rc == 0)) { |
23d9e60b | 919 | if (st->out_len == 0) |
ecbd95c1 BH |
920 | /* Transfer ownership of the skb */ |
921 | buffer->skb = skb; | |
b9b39b62 | 922 | |
23d9e60b | 923 | end_of_packet = st->out_len == 0 || st->packet_space == 0; |
ecbd95c1 | 924 | buffer->continuation = !end_of_packet; |
b9b39b62 | 925 | |
23d9e60b | 926 | if (st->in_len == 0) { |
ecbd95c1 | 927 | /* Transfer ownership of the pci mapping */ |
23d9e60b BH |
928 | buffer->unmap_len = st->unmap_len; |
929 | buffer->unmap_single = st->unmap_single; | |
930 | st->unmap_len = 0; | |
ecbd95c1 BH |
931 | } |
932 | } | |
933 | ||
23d9e60b | 934 | st->dma_addr += n; |
b9b39b62 BH |
935 | return rc; |
936 | } | |
937 | ||
938 | ||
939 | /** | |
940 | * tso_start_new_packet - generate a new header and prepare for the new packet | |
941 | * @tx_queue: Efx TX queue | |
942 | * @skb: Socket buffer | |
943 | * @st: TSO state | |
944 | * | |
945 | * Generate a new header and prepare for the new packet. Return 0 on | |
946 | * success, or -1 if failed to alloc header. | |
947 | */ | |
4d566063 BH |
948 | static int tso_start_new_packet(struct efx_tx_queue *tx_queue, |
949 | const struct sk_buff *skb, | |
950 | struct tso_state *st) | |
b9b39b62 BH |
951 | { |
952 | struct efx_tso_header *tsoh; | |
953 | struct iphdr *tsoh_iph; | |
954 | struct tcphdr *tsoh_th; | |
955 | unsigned ip_length; | |
956 | u8 *header; | |
957 | ||
958 | /* Allocate a DMA-mapped header buffer. */ | |
23d9e60b | 959 | if (likely(TSOH_SIZE(st->header_len) <= TSOH_STD_SIZE)) { |
b3475645 | 960 | if (tx_queue->tso_headers_free == NULL) { |
b9b39b62 BH |
961 | if (efx_tsoh_block_alloc(tx_queue)) |
962 | return -1; | |
b3475645 | 963 | } |
b9b39b62 BH |
964 | EFX_BUG_ON_PARANOID(!tx_queue->tso_headers_free); |
965 | tsoh = tx_queue->tso_headers_free; | |
966 | tx_queue->tso_headers_free = tsoh->next; | |
967 | tsoh->unmap_len = 0; | |
968 | } else { | |
969 | tx_queue->tso_long_headers++; | |
23d9e60b | 970 | tsoh = efx_tsoh_heap_alloc(tx_queue, st->header_len); |
b9b39b62 BH |
971 | if (unlikely(!tsoh)) |
972 | return -1; | |
973 | } | |
974 | ||
975 | header = TSOH_BUFFER(tsoh); | |
976 | tsoh_th = (struct tcphdr *)(header + SKB_TCP_OFF(skb)); | |
977 | tsoh_iph = (struct iphdr *)(header + SKB_IPV4_OFF(skb)); | |
978 | ||
979 | /* Copy and update the headers. */ | |
23d9e60b | 980 | memcpy(header, skb->data, st->header_len); |
b9b39b62 BH |
981 | |
982 | tsoh_th->seq = htonl(st->seqnum); | |
983 | st->seqnum += skb_shinfo(skb)->gso_size; | |
23d9e60b | 984 | if (st->out_len > skb_shinfo(skb)->gso_size) { |
b9b39b62 | 985 | /* This packet will not finish the TSO burst. */ |
23d9e60b | 986 | ip_length = st->full_packet_size - ETH_HDR_LEN(skb); |
b9b39b62 BH |
987 | tsoh_th->fin = 0; |
988 | tsoh_th->psh = 0; | |
989 | } else { | |
990 | /* This packet will be the last in the TSO burst. */ | |
23d9e60b | 991 | ip_length = st->header_len - ETH_HDR_LEN(skb) + st->out_len; |
b9b39b62 BH |
992 | tsoh_th->fin = tcp_hdr(skb)->fin; |
993 | tsoh_th->psh = tcp_hdr(skb)->psh; | |
994 | } | |
995 | tsoh_iph->tot_len = htons(ip_length); | |
996 | ||
997 | /* Linux leaves suitable gaps in the IP ID space for us to fill. */ | |
23d9e60b BH |
998 | tsoh_iph->id = htons(st->ipv4_id); |
999 | st->ipv4_id++; | |
b9b39b62 BH |
1000 | |
1001 | st->packet_space = skb_shinfo(skb)->gso_size; | |
1002 | ++tx_queue->tso_packets; | |
1003 | ||
1004 | /* Form a descriptor for this header. */ | |
23d9e60b | 1005 | efx_tso_put_header(tx_queue, tsoh, st->header_len); |
b9b39b62 BH |
1006 | |
1007 | return 0; | |
1008 | } | |
1009 | ||
1010 | ||
1011 | /** | |
1012 | * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer | |
1013 | * @tx_queue: Efx TX queue | |
1014 | * @skb: Socket buffer | |
1015 | * | |
1016 | * Context: You must hold netif_tx_lock() to call this function. | |
1017 | * | |
1018 | * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if | |
1019 | * @skb was not enqueued. In all cases @skb is consumed. Return | |
1020 | * %NETDEV_TX_OK or %NETDEV_TX_BUSY. | |
1021 | */ | |
1022 | static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, | |
1023 | const struct sk_buff *skb) | |
1024 | { | |
ecbd95c1 | 1025 | struct efx_nic *efx = tx_queue->efx; |
b9b39b62 BH |
1026 | int frag_i, rc, rc2 = NETDEV_TX_OK; |
1027 | struct tso_state state; | |
b9b39b62 BH |
1028 | |
1029 | /* Verify TSO is safe - these checks should never fail. */ | |
1030 | efx_tso_check_safe(skb); | |
1031 | ||
1032 | EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); | |
1033 | ||
1034 | tso_start(&state, skb); | |
1035 | ||
1036 | /* Assume that skb header area contains exactly the headers, and | |
1037 | * all payload is in the frag list. | |
1038 | */ | |
23d9e60b | 1039 | if (skb_headlen(skb) == state.header_len) { |
b9b39b62 BH |
1040 | /* Grab the first payload fragment. */ |
1041 | EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1); | |
1042 | frag_i = 0; | |
ecbd95c1 BH |
1043 | rc = tso_get_fragment(&state, efx, |
1044 | skb_shinfo(skb)->frags + frag_i); | |
b9b39b62 BH |
1045 | if (rc) |
1046 | goto mem_err; | |
1047 | } else { | |
ecbd95c1 | 1048 | rc = tso_get_head_fragment(&state, efx, skb); |
b9b39b62 BH |
1049 | if (rc) |
1050 | goto mem_err; | |
1051 | frag_i = -1; | |
1052 | } | |
1053 | ||
1054 | if (tso_start_new_packet(tx_queue, skb, &state) < 0) | |
1055 | goto mem_err; | |
1056 | ||
1057 | while (1) { | |
1058 | rc = tso_fill_packet_with_fragment(tx_queue, skb, &state); | |
1059 | if (unlikely(rc)) | |
1060 | goto stop; | |
1061 | ||
1062 | /* Move onto the next fragment? */ | |
23d9e60b | 1063 | if (state.in_len == 0) { |
b9b39b62 BH |
1064 | if (++frag_i >= skb_shinfo(skb)->nr_frags) |
1065 | /* End of payload reached. */ | |
1066 | break; | |
ecbd95c1 BH |
1067 | rc = tso_get_fragment(&state, efx, |
1068 | skb_shinfo(skb)->frags + frag_i); | |
b9b39b62 BH |
1069 | if (rc) |
1070 | goto mem_err; | |
1071 | } | |
1072 | ||
1073 | /* Start at new packet? */ | |
1074 | if (state.packet_space == 0 && | |
1075 | tso_start_new_packet(tx_queue, skb, &state) < 0) | |
1076 | goto mem_err; | |
1077 | } | |
1078 | ||
1079 | /* Pass off to hardware */ | |
1080 | falcon_push_buffers(tx_queue); | |
1081 | ||
1082 | tx_queue->tso_bursts++; | |
1083 | return NETDEV_TX_OK; | |
1084 | ||
1085 | mem_err: | |
ecbd95c1 | 1086 | EFX_ERR(efx, "Out of memory for TSO headers, or PCI mapping error\n"); |
b9b39b62 BH |
1087 | dev_kfree_skb_any((struct sk_buff *)skb); |
1088 | goto unwind; | |
1089 | ||
1090 | stop: | |
1091 | rc2 = NETDEV_TX_BUSY; | |
1092 | ||
1093 | /* Stop the queue if it wasn't stopped before. */ | |
1094 | if (tx_queue->stopped == 1) | |
ecbd95c1 | 1095 | efx_stop_queue(efx); |
b9b39b62 BH |
1096 | |
1097 | unwind: | |
5988b63a | 1098 | /* Free the DMA mapping we were in the process of writing out */ |
23d9e60b BH |
1099 | if (state.unmap_len) { |
1100 | if (state.unmap_single) | |
1101 | pci_unmap_single(efx->pci_dev, state.unmap_addr, | |
1102 | state.unmap_len, PCI_DMA_TODEVICE); | |
ecbd95c1 | 1103 | else |
23d9e60b BH |
1104 | pci_unmap_page(efx->pci_dev, state.unmap_addr, |
1105 | state.unmap_len, PCI_DMA_TODEVICE); | |
ecbd95c1 | 1106 | } |
5988b63a | 1107 | |
b9b39b62 BH |
1108 | efx_enqueue_unwind(tx_queue); |
1109 | return rc2; | |
1110 | } | |
1111 | ||
1112 | ||
1113 | /* | |
1114 | * Free up all TSO datastructures associated with tx_queue. This | |
1115 | * routine should be called only once the tx_queue is both empty and | |
1116 | * will no longer be used. | |
1117 | */ | |
1118 | static void efx_fini_tso(struct efx_tx_queue *tx_queue) | |
1119 | { | |
1120 | unsigned i; | |
1121 | ||
b3475645 | 1122 | if (tx_queue->buffer) { |
b9b39b62 BH |
1123 | for (i = 0; i <= tx_queue->efx->type->txd_ring_mask; ++i) |
1124 | efx_tsoh_free(tx_queue, &tx_queue->buffer[i]); | |
b3475645 | 1125 | } |
b9b39b62 BH |
1126 | |
1127 | while (tx_queue->tso_headers_free != NULL) | |
1128 | efx_tsoh_block_free(tx_queue, tx_queue->tso_headers_free, | |
1129 | tx_queue->efx->pci_dev); | |
1130 | } |