1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This file is based on code from OCTEON SDK by Cavium Networks.
4 *
5 * Copyright (c) 2003-2010 Cavium Networks
6 */
7
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/cache.h>
11 #include <linux/cpumask.h>
12 #include <linux/netdevice.h>
13 #include <linux/etherdevice.h>
14 #include <linux/ip.h>
15 #include <linux/string.h>
16 #include <linux/prefetch.h>
17 #include <linux/ratelimit.h>
18 #include <linux/smp.h>
19 #include <linux/interrupt.h>
20 #include <net/dst.h>
21 #ifdef CONFIG_XFRM
22 #include <linux/xfrm.h>
23 #include <net/xfrm.h>
24 #endif /* CONFIG_XFRM */
25
26 #include "octeon-ethernet.h"
27 #include "ethernet-defines.h"
28 #include "ethernet-mem.h"
29 #include "ethernet-rx.h"
30 #include "ethernet-util.h"
31
32 static atomic_t oct_rx_ready = ATOMIC_INIT(0);
33
34 static struct oct_rx_group {
35 int irq;
36 int group;
37 struct napi_struct napi;
38 } oct_rx_group[16];
39
40 /**
41 * cvm_oct_do_interrupt - interrupt handler.
42 * @irq: Interrupt number.
43 * @napi_id: Cookie to identify the NAPI instance.
44 *
45 * The interrupt occurs whenever the POW has packets in our group.
46 *
47 */
48 static irqreturn_t cvm_oct_do_interrupt(int irq, void *napi_id)
49 {
50 /* Disable the IRQ and start napi_poll. */
51 disable_irq_nosync(irq);
52 napi_schedule(napi_id);
53
54 return IRQ_HANDLED;
55 }
56
57 /**
58 * cvm_oct_check_rcv_error - process receive errors
59 * @work: Work queue entry pointing to the packet.
60 *
61 * Returns Non-zero if the packet can be dropped, zero otherwise.
62 */
63 static inline int cvm_oct_check_rcv_error(cvmx_wqe_t *work)
64 {
65 int port;
66
67 if (octeon_has_feature(OCTEON_FEATURE_PKND))
68 port = work->word0.pip.cn68xx.pknd;
69 else
70 port = work->word1.cn38xx.ipprt;
71
72 if ((work->word2.snoip.err_code == 10) && (work->word1.len <= 64)) {
73 /*
74 * Ignore length errors on min size packets. Some
75 * equipment incorrectly pads packets to 64+4FCS
76 * instead of 60+4FCS. Note these packets still get
77 * counted as frame errors.
78 */
79 } else if (work->word2.snoip.err_code == 5 ||
80 work->word2.snoip.err_code == 7) {
81 /*
82 * We received a packet with either an alignment error
83 * or a FCS error. This may be signalling that we are
84 * running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK]
85 * off. If this is the case we need to parse the
86 * packet to determine if we can remove a non spec
87 * preamble and generate a correct packet.
88 */
89 int interface = cvmx_helper_get_interface_num(port);
90 int index = cvmx_helper_get_interface_index_num(port);
91 union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
92
93 gmxx_rxx_frm_ctl.u64 =
94 cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
95 if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
96 u8 *ptr =
97 cvmx_phys_to_ptr(work->packet_ptr.s.addr);
98 int i = 0;
99
100 while (i < work->word1.len - 1) {
101 if (*ptr != 0x55)
102 break;
103 ptr++;
104 i++;
105 }
106
107 if (*ptr == 0xd5) {
108 /* Port received 0xd5 preamble */
109 work->packet_ptr.s.addr += i + 1;
110 work->word1.len -= i + 5;
111 } else if ((*ptr & 0xf) == 0xd) {
112 /* Port received 0xd preamble */
113 work->packet_ptr.s.addr += i;
114 work->word1.len -= i + 4;
115 for (i = 0; i < work->word1.len; i++) {
116 *ptr =
117 ((*ptr & 0xf0) >> 4) |
118 ((*(ptr + 1) & 0xf) << 4);
119 ptr++;
120 }
121 } else {
122 printk_ratelimited("Port %d unknown preamble, packet dropped\n",
123 port);
124 cvm_oct_free_work(work);
125 return 1;
126 }
127 }
128 } else {
129 printk_ratelimited("Port %d receive error code %d, packet dropped\n",
130 port, work->word2.snoip.err_code);
131 cvm_oct_free_work(work);
132 return 1;
133 }
134
135 return 0;
136 }
137
138 static void copy_segments_to_skb(cvmx_wqe_t *work, struct sk_buff *skb)
139 {
140 int segments = work->word2.s.bufs;
141 union cvmx_buf_ptr segment_ptr = work->packet_ptr;
142 int len = work->word1.len;
143 int segment_size;
144
145 while (segments--) {
146 union cvmx_buf_ptr next_ptr;
147
148 next_ptr = *(union cvmx_buf_ptr *)
149 cvmx_phys_to_ptr(segment_ptr.s.addr - 8);
150
151 /*
152 * Octeon Errata PKI-100: The segment size is wrong.
153 *
154 * Until it is fixed, calculate the segment size based on
155 * the packet pool buffer size.
156 * When it is fixed, the following line should be replaced
157 * with this one:
158 * int segment_size = segment_ptr.s.size;
159 */
160 segment_size =
161 CVMX_FPA_PACKET_POOL_SIZE -
162 (segment_ptr.s.addr -
163 (((segment_ptr.s.addr >> 7) -
164 segment_ptr.s.back) << 7));
165
166 /* Don't copy more than what is left in the packet */
167 if (segment_size > len)
168 segment_size = len;
169
170 /* Copy the data into the packet */
171 skb_put_data(skb, cvmx_phys_to_ptr(segment_ptr.s.addr),
172 segment_size);
173 len -= segment_size;
174 segment_ptr = next_ptr;
175 }
176 }
177
178 static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget)
179 {
180 const int coreid = cvmx_get_core_num();
181 u64 old_group_mask;
182 u64 old_scratch;
183 int rx_count = 0;
184 int did_work_request = 0;
185 int packet_not_copied;
186
187 /* Prefetch cvm_oct_device since we know we need it soon */
188 prefetch(cvm_oct_device);
189
190 if (USE_ASYNC_IOBDMA) {
191 /* Save scratch in case userspace is using it */
192 CVMX_SYNCIOBDMA;
193 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
194 }
195
196 /* Only allow work for our group (and preserve priorities) */
197 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
198 old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid));
199 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid),
200 BIT(rx_group->group));
201 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
202 } else {
203 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
204 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
205 (old_group_mask & ~0xFFFFull) |
206 BIT(rx_group->group));
207 }
208
209 if (USE_ASYNC_IOBDMA) {
210 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
211 did_work_request = 1;
212 }
213
214 while (rx_count < budget) {
215 struct sk_buff *skb = NULL;
216 struct sk_buff **pskb = NULL;
217 int skb_in_hw;
218 cvmx_wqe_t *work;
219 int port;
220
221 if (USE_ASYNC_IOBDMA && did_work_request)
222 work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
223 else
224 work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
225
226 prefetch(work);
227 did_work_request = 0;
228 if (!work) {
229 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
230 cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS,
231 BIT(rx_group->group));
232 cvmx_write_csr(CVMX_SSO_WQ_INT,
233 BIT(rx_group->group));
234 } else {
235 union cvmx_pow_wq_int wq_int;
236
237 wq_int.u64 = 0;
238 wq_int.s.iq_dis = BIT(rx_group->group);
239 wq_int.s.wq_int = BIT(rx_group->group);
240 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
241 }
242 break;
243 }
244 pskb = (struct sk_buff **)
245 (cvm_oct_get_buffer_ptr(work->packet_ptr) -
246 sizeof(void *));
247 prefetch(pskb);
248
249 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
250 cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
251 CVMX_POW_NO_WAIT);
252 did_work_request = 1;
253 }
254 rx_count++;
255
256 skb_in_hw = work->word2.s.bufs == 1;
257 if (likely(skb_in_hw)) {
258 skb = *pskb;
259 prefetch(&skb->head);
260 prefetch(&skb->len);
261 }
262
263 if (octeon_has_feature(OCTEON_FEATURE_PKND))
264 port = work->word0.pip.cn68xx.pknd;
265 else
266 port = work->word1.cn38xx.ipprt;
267
268 prefetch(cvm_oct_device[port]);
269
270 /* Immediately throw away all packets with receive errors */
271 if (unlikely(work->word2.snoip.rcv_error)) {
272 if (cvm_oct_check_rcv_error(work))
273 continue;
274 }
275
276 /*
277 * We can only use the zero copy path if skbuffs are
278 * in the FPA pool and the packet fits in a single
279 * buffer.
280 */
281 if (likely(skb_in_hw)) {
282 skb->data = skb->head + work->packet_ptr.s.addr -
283 cvmx_ptr_to_phys(skb->head);
284 prefetch(skb->data);
285 skb->len = work->word1.len;
286 skb_set_tail_pointer(skb, skb->len);
287 packet_not_copied = 1;
288 } else {
289 /*
290 * We have to copy the packet. First allocate
291 * an skbuff for it.
292 */
293 skb = dev_alloc_skb(work->word1.len);
294 if (!skb) {
295 cvm_oct_free_work(work);
296 continue;
297 }
298
299 /*
300 * Check if we've received a packet that was
301 * entirely stored in the work entry.
302 */
303 if (unlikely(work->word2.s.bufs == 0)) {
304 u8 *ptr = work->packet_data;
305
306 if (likely(!work->word2.s.not_IP)) {
307 /*
308 * The beginning of the packet
309 * moves for IP packets.
310 */
311 if (work->word2.s.is_v6)
312 ptr += 2;
313 else
314 ptr += 6;
315 }
316 skb_put_data(skb, ptr, work->word1.len);
317 /* No packet buffers to free */
318 } else {
319 copy_segments_to_skb(work, skb);
320 }
321 packet_not_copied = 0;
322 }
323 if (likely((port < TOTAL_NUMBER_OF_PORTS) &&
324 cvm_oct_device[port])) {
325 struct net_device *dev = cvm_oct_device[port];
326
327 /*
328 * Only accept packets for devices that are
329 * currently up.
330 */
331 if (likely(dev->flags & IFF_UP)) {
332 skb->protocol = eth_type_trans(skb, dev);
333 skb->dev = dev;
334
335 if (unlikely(work->word2.s.not_IP ||
336 work->word2.s.IP_exc ||
337 work->word2.s.L4_error ||
338 !work->word2.s.tcp_or_udp))
339 skb->ip_summed = CHECKSUM_NONE;
340 else
341 skb->ip_summed = CHECKSUM_UNNECESSARY;
342
343 /* Increment RX stats for virtual ports */
344 if (port >= CVMX_PIP_NUM_INPUT_PORTS) {
345 dev->stats.rx_packets++;
346 dev->stats.rx_bytes += skb->len;
347 }
348 netif_receive_skb(skb);
349 } else {
350 /*
351 * Drop any packet received for a device that
352 * isn't up.
353 */
354 dev->stats.rx_dropped++;
355 dev_kfree_skb_irq(skb);
356 }
357 } else {
358 /*
359 * Drop any packet received for a device that
360 * doesn't exist.
361 */
362 printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
363 port);
364 dev_kfree_skb_irq(skb);
365 }
366 /*
367 * Check to see if the skbuff and work share the same
368 * packet buffer.
369 */
370 if (likely(packet_not_copied)) {
371 /*
372 * This buffer needs to be replaced, increment
373 * the number of buffers we need to free by
374 * one.
375 */
376 cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
377 1);
378
379 cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, 1);
380 } else {
381 cvm_oct_free_work(work);
382 }
383 }
384 /* Restore the original POW group mask */
385 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
386 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), old_group_mask);
387 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
388 } else {
389 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
390 }
391
392 if (USE_ASYNC_IOBDMA) {
393 /* Restore the scratch area */
394 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
395 }
396 cvm_oct_rx_refill_pool(0);
397
398 return rx_count;
399 }
400
401 /**
402 * cvm_oct_napi_poll - the NAPI poll function.
403 * @napi: The NAPI instance.
404 * @budget: Maximum number of packets to receive.
405 *
406 * Returns the number of packets processed.
407 */
408 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
409 {
410 struct oct_rx_group *rx_group = container_of(napi, struct oct_rx_group,
411 napi);
412 int rx_count;
413
414 rx_count = cvm_oct_poll(rx_group, budget);
415
416 if (rx_count < budget) {
417 /* No more work */
418 napi_complete_done(napi, rx_count);
419 enable_irq(rx_group->irq);
420 }
421 return rx_count;
422 }
423
424 #ifdef CONFIG_NET_POLL_CONTROLLER
425 /**
426 * cvm_oct_poll_controller - poll for receive packets
427 * device.
428 *
429 * @dev: Device to poll. Unused
430 */
431 void cvm_oct_poll_controller(struct net_device *dev)
432 {
433 int i;
434
435 if (!atomic_read(&oct_rx_ready))
436 return;
437
438 for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
439 if (!(pow_receive_groups & BIT(i)))
440 continue;
441
442 cvm_oct_poll(&oct_rx_group[i], 16);
443 }
444 }
445 #endif
446
447 void cvm_oct_rx_initialize(void)
448 {
449 int i;
450 struct net_device *dev_for_napi = NULL;
451
452 for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
453 if (cvm_oct_device[i]) {
454 dev_for_napi = cvm_oct_device[i];
455 break;
456 }
457 }
458
459 if (!dev_for_napi)
460 panic("No net_devices were allocated.");
461
462 for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
463 int ret;
464
465 if (!(pow_receive_groups & BIT(i)))
466 continue;
467
468 netif_napi_add(dev_for_napi, &oct_rx_group[i].napi,
469 cvm_oct_napi_poll, rx_napi_weight);
470 napi_enable(&oct_rx_group[i].napi);
471
472 oct_rx_group[i].irq = OCTEON_IRQ_WORKQ0 + i;
473 oct_rx_group[i].group = i;
474
475 /* Register an IRQ handler to receive POW interrupts */
476 ret = request_irq(oct_rx_group[i].irq, cvm_oct_do_interrupt, 0,
477 "Ethernet", &oct_rx_group[i].napi);
478 if (ret)
479 panic("Could not acquire Ethernet IRQ %d\n",
480 oct_rx_group[i].irq);
481
482 disable_irq_nosync(oct_rx_group[i].irq);
483
484 /* Enable POW interrupt when our port has at least one packet */
485 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
486 union cvmx_sso_wq_int_thrx int_thr;
487 union cvmx_pow_wq_int_pc int_pc;
488
489 int_thr.u64 = 0;
490 int_thr.s.tc_en = 1;
491 int_thr.s.tc_thr = 1;
492 cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), int_thr.u64);
493
494 int_pc.u64 = 0;
495 int_pc.s.pc_thr = 5;
496 cvmx_write_csr(CVMX_SSO_WQ_INT_PC, int_pc.u64);
497 } else {
498 union cvmx_pow_wq_int_thrx int_thr;
499 union cvmx_pow_wq_int_pc int_pc;
500
501 int_thr.u64 = 0;
502 int_thr.s.tc_en = 1;
503 int_thr.s.tc_thr = 1;
504 cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), int_thr.u64);
505
506 int_pc.u64 = 0;
507 int_pc.s.pc_thr = 5;
508 cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
509 }
510
511 /* Schedule NAPI now. This will indirectly enable the
512 * interrupt.
513 */
514 napi_schedule(&oct_rx_group[i].napi);
515 }
516 atomic_inc(&oct_rx_ready);
517 }
518
519 void cvm_oct_rx_shutdown(void)
520 {
521 int i;
522
523 for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
524 if (!(pow_receive_groups & BIT(i)))
525 continue;
526
527 /* Disable POW interrupt */
528 if (OCTEON_IS_MODEL(OCTEON_CN68XX))
529 cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), 0);
530 else
531 cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0);
532
533 /* Free the interrupt handler */
534 free_irq(oct_rx_group[i].irq, cvm_oct_device);
535
536 netif_napi_del(&oct_rx_group[i].napi);
537 }
538 }