1 // SPDX-License-Identifier: GPL-2.0
2 /* Marvell Octeon EP (EndPoint) VF Ethernet Driver
3 *
4 * Copyright (C) 2020 Marvell.
5 *
6 */
7
8 #include <linux/pci.h>
9 #include <linux/etherdevice.h>
10 #include <linux/vmalloc.h>
11
12 #include "octep_vf_config.h"
13 #include "octep_vf_main.h"
14
octep_vf_oq_reset_indices(struct octep_vf_oq * oq)15 static void octep_vf_oq_reset_indices(struct octep_vf_oq *oq)
16 {
17 oq->host_read_idx = 0;
18 oq->host_refill_idx = 0;
19 oq->refill_count = 0;
20 oq->last_pkt_count = 0;
21 oq->pkts_pending = 0;
22 }
23
24 /**
25 * octep_vf_oq_fill_ring_buffers() - fill initial receive buffers for Rx ring.
26 *
27 * @oq: Octeon Rx queue data structure.
28 *
29 * Return: 0, if successfully filled receive buffers for all descriptors.
30 * -ENOMEM, if failed to allocate a buffer or failed to map for DMA.
31 */
octep_vf_oq_fill_ring_buffers(struct octep_vf_oq * oq)32 static int octep_vf_oq_fill_ring_buffers(struct octep_vf_oq *oq)
33 {
34 struct octep_vf_oq_desc_hw *desc_ring = oq->desc_ring;
35 struct page *page;
36 u32 i;
37
38 for (i = 0; i < oq->max_count; i++) {
39 page = dev_alloc_page();
40 if (unlikely(!page)) {
41 dev_err(oq->dev, "Rx buffer alloc failed\n");
42 goto rx_buf_alloc_err;
43 }
44 desc_ring[i].buffer_ptr = dma_map_page(oq->dev, page, 0,
45 PAGE_SIZE,
46 DMA_FROM_DEVICE);
47 if (dma_mapping_error(oq->dev, desc_ring[i].buffer_ptr)) {
48 dev_err(oq->dev,
49 "OQ-%d buffer alloc: DMA mapping error!\n",
50 oq->q_no);
51 goto dma_map_err;
52 }
53 oq->buff_info[i].page = page;
54 }
55
56 return 0;
57
58 dma_map_err:
59 put_page(page);
60 rx_buf_alloc_err:
61 while (i) {
62 i--;
63 dma_unmap_page(oq->dev, desc_ring[i].buffer_ptr, PAGE_SIZE, DMA_FROM_DEVICE);
64 put_page(oq->buff_info[i].page);
65 oq->buff_info[i].page = NULL;
66 }
67
68 return -ENOMEM;
69 }
70
71 /**
72 * octep_vf_oq_refill() - refill buffers for used Rx ring descriptors.
73 *
74 * @oct: Octeon device private data structure.
75 * @oq: Octeon Rx queue data structure.
76 *
77 * Return: number of descriptors successfully refilled with receive buffers.
78 */
octep_vf_oq_refill(struct octep_vf_device * oct,struct octep_vf_oq * oq)79 static int octep_vf_oq_refill(struct octep_vf_device *oct, struct octep_vf_oq *oq)
80 {
81 struct octep_vf_oq_desc_hw *desc_ring = oq->desc_ring;
82 struct page *page;
83 u32 refill_idx, i;
84
85 refill_idx = oq->host_refill_idx;
86 for (i = 0; i < oq->refill_count; i++) {
87 page = dev_alloc_page();
88 if (unlikely(!page)) {
89 dev_err(oq->dev, "refill: rx buffer alloc failed\n");
90 oq->stats.alloc_failures++;
91 break;
92 }
93
94 desc_ring[refill_idx].buffer_ptr = dma_map_page(oq->dev, page, 0,
95 PAGE_SIZE, DMA_FROM_DEVICE);
96 if (dma_mapping_error(oq->dev, desc_ring[refill_idx].buffer_ptr)) {
97 dev_err(oq->dev,
98 "OQ-%d buffer refill: DMA mapping error!\n",
99 oq->q_no);
100 put_page(page);
101 oq->stats.alloc_failures++;
102 break;
103 }
104 oq->buff_info[refill_idx].page = page;
105 refill_idx++;
106 if (refill_idx == oq->max_count)
107 refill_idx = 0;
108 }
109 oq->host_refill_idx = refill_idx;
110 oq->refill_count -= i;
111
112 return i;
113 }
114
115 /**
116 * octep_vf_setup_oq() - Setup a Rx queue.
117 *
118 * @oct: Octeon device private data structure.
119 * @q_no: Rx queue number to be setup.
120 *
121 * Allocate resources for a Rx queue.
122 */
octep_vf_setup_oq(struct octep_vf_device * oct,int q_no)123 static int octep_vf_setup_oq(struct octep_vf_device *oct, int q_no)
124 {
125 struct octep_vf_oq *oq;
126 u32 desc_ring_size;
127
128 oq = vzalloc(sizeof(*oq));
129 if (!oq)
130 goto create_oq_fail;
131 oct->oq[q_no] = oq;
132
133 oq->octep_vf_dev = oct;
134 oq->netdev = oct->netdev;
135 oq->dev = &oct->pdev->dev;
136 oq->q_no = q_no;
137 oq->max_count = CFG_GET_OQ_NUM_DESC(oct->conf);
138 oq->ring_size_mask = oq->max_count - 1;
139 oq->buffer_size = CFG_GET_OQ_BUF_SIZE(oct->conf);
140 oq->max_single_buffer_size = oq->buffer_size - OCTEP_VF_OQ_RESP_HW_SIZE;
141
142 /* When the hardware/firmware supports additional capabilities,
143 * additional header is filled-in by Octeon after length field in
144 * Rx packets. this header contains additional packet information.
145 */
146 if (oct->fw_info.rx_ol_flags)
147 oq->max_single_buffer_size -= OCTEP_VF_OQ_RESP_HW_EXT_SIZE;
148
149 oq->refill_threshold = CFG_GET_OQ_REFILL_THRESHOLD(oct->conf);
150
151 desc_ring_size = oq->max_count * OCTEP_VF_OQ_DESC_SIZE;
152 oq->desc_ring = dma_alloc_coherent(oq->dev, desc_ring_size,
153 &oq->desc_ring_dma, GFP_KERNEL);
154
155 if (unlikely(!oq->desc_ring)) {
156 dev_err(oq->dev,
157 "Failed to allocate DMA memory for OQ-%d !!\n", q_no);
158 goto desc_dma_alloc_err;
159 }
160
161 oq->buff_info = vzalloc(oq->max_count * OCTEP_VF_OQ_RECVBUF_SIZE);
162
163 if (unlikely(!oq->buff_info)) {
164 dev_err(&oct->pdev->dev,
165 "Failed to allocate buffer info for OQ-%d\n", q_no);
166 goto buf_list_err;
167 }
168
169 if (octep_vf_oq_fill_ring_buffers(oq))
170 goto oq_fill_buff_err;
171
172 octep_vf_oq_reset_indices(oq);
173 oct->hw_ops.setup_oq_regs(oct, q_no);
174 oct->num_oqs++;
175
176 return 0;
177
178 oq_fill_buff_err:
179 vfree(oq->buff_info);
180 oq->buff_info = NULL;
181 buf_list_err:
182 dma_free_coherent(oq->dev, desc_ring_size,
183 oq->desc_ring, oq->desc_ring_dma);
184 oq->desc_ring = NULL;
185 desc_dma_alloc_err:
186 vfree(oq);
187 oct->oq[q_no] = NULL;
188 create_oq_fail:
189 return -ENOMEM;
190 }
191
192 /**
193 * octep_vf_oq_free_ring_buffers() - Free ring buffers.
194 *
195 * @oq: Octeon Rx queue data structure.
196 *
197 * Free receive buffers in unused Rx queue descriptors.
198 */
octep_vf_oq_free_ring_buffers(struct octep_vf_oq * oq)199 static void octep_vf_oq_free_ring_buffers(struct octep_vf_oq *oq)
200 {
201 struct octep_vf_oq_desc_hw *desc_ring = oq->desc_ring;
202 int i;
203
204 if (!oq->desc_ring || !oq->buff_info)
205 return;
206
207 for (i = 0; i < oq->max_count; i++) {
208 if (oq->buff_info[i].page) {
209 dma_unmap_page(oq->dev, desc_ring[i].buffer_ptr,
210 PAGE_SIZE, DMA_FROM_DEVICE);
211 put_page(oq->buff_info[i].page);
212 oq->buff_info[i].page = NULL;
213 desc_ring[i].buffer_ptr = 0;
214 }
215 }
216 octep_vf_oq_reset_indices(oq);
217 }
218
219 /**
220 * octep_vf_free_oq() - Free Rx queue resources.
221 *
222 * @oq: Octeon Rx queue data structure.
223 *
224 * Free all resources of a Rx queue.
225 */
octep_vf_free_oq(struct octep_vf_oq * oq)226 static int octep_vf_free_oq(struct octep_vf_oq *oq)
227 {
228 struct octep_vf_device *oct = oq->octep_vf_dev;
229 int q_no = oq->q_no;
230
231 octep_vf_oq_free_ring_buffers(oq);
232
233 vfree(oq->buff_info);
234
235 if (oq->desc_ring)
236 dma_free_coherent(oq->dev,
237 oq->max_count * OCTEP_VF_OQ_DESC_SIZE,
238 oq->desc_ring, oq->desc_ring_dma);
239
240 vfree(oq);
241 oct->oq[q_no] = NULL;
242 oct->num_oqs--;
243 return 0;
244 }
245
246 /**
247 * octep_vf_setup_oqs() - setup resources for all Rx queues.
248 *
249 * @oct: Octeon device private data structure.
250 */
octep_vf_setup_oqs(struct octep_vf_device * oct)251 int octep_vf_setup_oqs(struct octep_vf_device *oct)
252 {
253 int i, retval = 0;
254
255 oct->num_oqs = 0;
256 for (i = 0; i < CFG_GET_PORTS_ACTIVE_IO_RINGS(oct->conf); i++) {
257 retval = octep_vf_setup_oq(oct, i);
258 if (retval) {
259 dev_err(&oct->pdev->dev,
260 "Failed to setup OQ(RxQ)-%d.\n", i);
261 goto oq_setup_err;
262 }
263 dev_dbg(&oct->pdev->dev, "Successfully setup OQ(RxQ)-%d.\n", i);
264 }
265
266 return 0;
267
268 oq_setup_err:
269 while (i) {
270 i--;
271 octep_vf_free_oq(oct->oq[i]);
272 }
273 return retval;
274 }
275
276 /**
277 * octep_vf_oq_dbell_init() - Initialize Rx queue doorbell.
278 *
279 * @oct: Octeon device private data structure.
280 *
281 * Write number of descriptors to Rx queue doorbell register.
282 */
octep_vf_oq_dbell_init(struct octep_vf_device * oct)283 void octep_vf_oq_dbell_init(struct octep_vf_device *oct)
284 {
285 int i;
286
287 for (i = 0; i < oct->num_oqs; i++)
288 writel(oct->oq[i]->max_count, oct->oq[i]->pkts_credit_reg);
289 }
290
291 /**
292 * octep_vf_free_oqs() - Free resources of all Rx queues.
293 *
294 * @oct: Octeon device private data structure.
295 */
octep_vf_free_oqs(struct octep_vf_device * oct)296 void octep_vf_free_oqs(struct octep_vf_device *oct)
297 {
298 int i;
299
300 for (i = 0; i < CFG_GET_PORTS_ACTIVE_IO_RINGS(oct->conf); i++) {
301 if (!oct->oq[i])
302 continue;
303 octep_vf_free_oq(oct->oq[i]);
304 dev_dbg(&oct->pdev->dev,
305 "Successfully freed OQ(RxQ)-%d.\n", i);
306 }
307 }
308
309 /**
310 * octep_vf_oq_check_hw_for_pkts() - Check for new Rx packets.
311 *
312 * @oct: Octeon device private data structure.
313 * @oq: Octeon Rx queue data structure.
314 *
315 * Return: packets received after previous check.
316 */
octep_vf_oq_check_hw_for_pkts(struct octep_vf_device * oct,struct octep_vf_oq * oq)317 static int octep_vf_oq_check_hw_for_pkts(struct octep_vf_device *oct,
318 struct octep_vf_oq *oq)
319 {
320 u32 pkt_count, new_pkts;
321
322 pkt_count = readl(oq->pkts_sent_reg);
323 new_pkts = pkt_count - oq->last_pkt_count;
324
325 /* Clear the hardware packets counter register if the rx queue is
326 * being processed continuously with-in a single interrupt and
327 * reached half its max value.
328 * this counter is not cleared every time read, to save write cycles.
329 */
330 if (unlikely(pkt_count > 0xF0000000U)) {
331 writel(pkt_count, oq->pkts_sent_reg);
332 pkt_count = readl(oq->pkts_sent_reg);
333 new_pkts += pkt_count;
334 }
335 oq->last_pkt_count = pkt_count;
336 oq->pkts_pending += new_pkts;
337 return new_pkts;
338 }
339
340 /**
341 * __octep_vf_oq_process_rx() - Process hardware Rx queue and push to stack.
342 *
343 * @oct: Octeon device private data structure.
344 * @oq: Octeon Rx queue data structure.
345 * @pkts_to_process: number of packets to be processed.
346 *
347 * Process the new packets in Rx queue.
348 * Packets larger than single Rx buffer arrive in consecutive descriptors.
349 * But, count returned by the API only accounts full packets, not fragments.
350 *
351 * Return: number of packets processed and pushed to stack.
352 */
__octep_vf_oq_process_rx(struct octep_vf_device * oct,struct octep_vf_oq * oq,u16 pkts_to_process)353 static int __octep_vf_oq_process_rx(struct octep_vf_device *oct,
354 struct octep_vf_oq *oq, u16 pkts_to_process)
355 {
356 struct octep_vf_oq_resp_hw_ext *resp_hw_ext = NULL;
357 netdev_features_t feat = oq->netdev->features;
358 struct octep_vf_rx_buffer *buff_info;
359 struct octep_vf_oq_resp_hw *resp_hw;
360 u32 pkt, rx_bytes, desc_used;
361 u16 data_offset, rx_ol_flags;
362 struct sk_buff *skb;
363 u32 read_idx;
364
365 read_idx = oq->host_read_idx;
366 rx_bytes = 0;
367 desc_used = 0;
368 for (pkt = 0; pkt < pkts_to_process; pkt++) {
369 buff_info = (struct octep_vf_rx_buffer *)&oq->buff_info[read_idx];
370 dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
371 PAGE_SIZE, DMA_FROM_DEVICE);
372 resp_hw = page_address(buff_info->page);
373 buff_info->page = NULL;
374
375 /* Swap the length field that is in Big-Endian to CPU */
376 buff_info->len = be64_to_cpu(resp_hw->length);
377 if (oct->fw_info.rx_ol_flags) {
378 /* Extended response header is immediately after
379 * response header (resp_hw)
380 */
381 resp_hw_ext = (struct octep_vf_oq_resp_hw_ext *)
382 (resp_hw + 1);
383 buff_info->len -= OCTEP_VF_OQ_RESP_HW_EXT_SIZE;
384 /* Packet Data is immediately after
385 * extended response header.
386 */
387 data_offset = OCTEP_VF_OQ_RESP_HW_SIZE +
388 OCTEP_VF_OQ_RESP_HW_EXT_SIZE;
389 rx_ol_flags = resp_hw_ext->rx_ol_flags;
390 } else {
391 /* Data is immediately after
392 * Hardware Rx response header.
393 */
394 data_offset = OCTEP_VF_OQ_RESP_HW_SIZE;
395 rx_ol_flags = 0;
396 }
397 rx_bytes += buff_info->len;
398
399 if (buff_info->len <= oq->max_single_buffer_size) {
400 skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
401 skb_reserve(skb, data_offset);
402 skb_put(skb, buff_info->len);
403 read_idx++;
404 desc_used++;
405 if (read_idx == oq->max_count)
406 read_idx = 0;
407 } else {
408 struct skb_shared_info *shinfo;
409 u16 data_len;
410
411 skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
412 skb_reserve(skb, data_offset);
413 /* Head fragment includes response header(s);
414 * subsequent fragments contains only data.
415 */
416 skb_put(skb, oq->max_single_buffer_size);
417 read_idx++;
418 desc_used++;
419 if (read_idx == oq->max_count)
420 read_idx = 0;
421
422 shinfo = skb_shinfo(skb);
423 data_len = buff_info->len - oq->max_single_buffer_size;
424 while (data_len) {
425 dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
426 PAGE_SIZE, DMA_FROM_DEVICE);
427 buff_info = (struct octep_vf_rx_buffer *)
428 &oq->buff_info[read_idx];
429 if (data_len < oq->buffer_size) {
430 buff_info->len = data_len;
431 data_len = 0;
432 } else {
433 buff_info->len = oq->buffer_size;
434 data_len -= oq->buffer_size;
435 }
436
437 skb_add_rx_frag(skb, shinfo->nr_frags,
438 buff_info->page, 0,
439 buff_info->len,
440 buff_info->len);
441 buff_info->page = NULL;
442 read_idx++;
443 desc_used++;
444 if (read_idx == oq->max_count)
445 read_idx = 0;
446 }
447 }
448
449 skb->dev = oq->netdev;
450 skb->protocol = eth_type_trans(skb, skb->dev);
451 if (feat & NETIF_F_RXCSUM &&
452 OCTEP_VF_RX_CSUM_VERIFIED(rx_ol_flags))
453 skb->ip_summed = CHECKSUM_UNNECESSARY;
454 else
455 skb->ip_summed = CHECKSUM_NONE;
456 napi_gro_receive(oq->napi, skb);
457 }
458
459 oq->host_read_idx = read_idx;
460 oq->refill_count += desc_used;
461 oq->stats.packets += pkt;
462 oq->stats.bytes += rx_bytes;
463
464 return pkt;
465 }
466
467 /**
468 * octep_vf_oq_process_rx() - Process Rx queue.
469 *
470 * @oq: Octeon Rx queue data structure.
471 * @budget: max number of packets can be processed in one invocation.
472 *
473 * Check for newly received packets and process them.
474 * Keeps checking for new packets until budget is used or no new packets seen.
475 *
476 * Return: number of packets processed.
477 */
octep_vf_oq_process_rx(struct octep_vf_oq * oq,int budget)478 int octep_vf_oq_process_rx(struct octep_vf_oq *oq, int budget)
479 {
480 u32 pkts_available, pkts_processed, total_pkts_processed;
481 struct octep_vf_device *oct = oq->octep_vf_dev;
482
483 pkts_available = 0;
484 pkts_processed = 0;
485 total_pkts_processed = 0;
486 while (total_pkts_processed < budget) {
487 /* update pending count only when current one exhausted */
488 if (oq->pkts_pending == 0)
489 octep_vf_oq_check_hw_for_pkts(oct, oq);
490 pkts_available = min(budget - total_pkts_processed,
491 oq->pkts_pending);
492 if (!pkts_available)
493 break;
494
495 pkts_processed = __octep_vf_oq_process_rx(oct, oq,
496 pkts_available);
497 oq->pkts_pending -= pkts_processed;
498 total_pkts_processed += pkts_processed;
499 }
500
501 if (oq->refill_count >= oq->refill_threshold) {
502 u32 desc_refilled = octep_vf_oq_refill(oct, oq);
503
504 /* flush pending writes before updating credits */
505 smp_wmb();
506 writel(desc_refilled, oq->pkts_credit_reg);
507 }
508
509 return total_pkts_processed;
510 }
511