1 /**********************************************************************
2 * Author: Cavium Networks
3 *
4 * Contact: support@caviumnetworks.com
5 * This file is part of the OCTEON SDK
6 *
7 * Copyright (c) 2003-2010 Cavium Networks
8 *
9 * This file is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License, Version 2, as
11 * published by the Free Software Foundation.
12 *
13 * This file is distributed in the hope that it will be useful, but
14 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
16 * NONINFRINGEMENT. See the GNU General Public License for more
17 * details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this file; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 * or visit http://www.gnu.org/licenses/.
23 *
24 * This file may also be available under a different license from Cavium.
25 * Contact Cavium Networks for more information
26 **********************************************************************/
27 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/cache.h>
30 #include <linux/cpumask.h>
31 #include <linux/netdevice.h>
32 #include <linux/etherdevice.h>
33 #include <linux/ip.h>
34 #include <linux/string.h>
35 #include <linux/prefetch.h>
36 #include <linux/ratelimit.h>
37 #include <linux/smp.h>
38 #include <linux/interrupt.h>
39 #include <net/dst.h>
40 #ifdef CONFIG_XFRM
41 #include <linux/xfrm.h>
42 #include <net/xfrm.h>
43 #endif /* CONFIG_XFRM */
44
45 #include <linux/atomic.h>
46
47 #include <asm/octeon/octeon.h>
48
49 #include "ethernet-defines.h"
50 #include "ethernet-mem.h"
51 #include "ethernet-rx.h"
52 #include "octeon-ethernet.h"
53 #include "ethernet-util.h"
54
55 #include <asm/octeon/cvmx-helper.h>
56 #include <asm/octeon/cvmx-wqe.h>
57 #include <asm/octeon/cvmx-fau.h>
58 #include <asm/octeon/cvmx-pow.h>
59 #include <asm/octeon/cvmx-pip.h>
60 #include <asm/octeon/cvmx-scratch.h>
61
62 #include <asm/octeon/cvmx-gmxx-defs.h>
63
64 static struct napi_struct cvm_oct_napi;
65
66 /**
67 * cvm_oct_do_interrupt - interrupt handler.
68 *
69 * The interrupt occurs whenever the POW has packets in our group.
70 *
71 */
cvm_oct_do_interrupt(int cpl,void * dev_id)72 static irqreturn_t cvm_oct_do_interrupt(int cpl, void *dev_id)
73 {
74 /* Disable the IRQ and start napi_poll. */
75 disable_irq_nosync(OCTEON_IRQ_WORKQ0 + pow_receive_group);
76 napi_schedule(&cvm_oct_napi);
77
78 return IRQ_HANDLED;
79 }
80
81 /**
82 * cvm_oct_check_rcv_error - process receive errors
83 * @work: Work queue entry pointing to the packet.
84 *
85 * Returns Non-zero if the packet can be dropped, zero otherwise.
86 */
cvm_oct_check_rcv_error(cvmx_wqe_t * work)87 static inline int cvm_oct_check_rcv_error(cvmx_wqe_t *work)
88 {
89 if ((work->word2.snoip.err_code == 10) && (work->len <= 64)) {
90 /*
91 * Ignore length errors on min size packets. Some
92 * equipment incorrectly pads packets to 64+4FCS
93 * instead of 60+4FCS. Note these packets still get
94 * counted as frame errors.
95 */
96 } else
97 if (USE_10MBPS_PREAMBLE_WORKAROUND
98 && ((work->word2.snoip.err_code == 5)
99 || (work->word2.snoip.err_code == 7))) {
100
101 /*
102 * We received a packet with either an alignment error
103 * or a FCS error. This may be signalling that we are
104 * running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK]
105 * off. If this is the case we need to parse the
106 * packet to determine if we can remove a non spec
107 * preamble and generate a correct packet.
108 */
109 int interface = cvmx_helper_get_interface_num(work->ipprt);
110 int index = cvmx_helper_get_interface_index_num(work->ipprt);
111 union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
112
113 gmxx_rxx_frm_ctl.u64 =
114 cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
115 if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
116
117 uint8_t *ptr =
118 cvmx_phys_to_ptr(work->packet_ptr.s.addr);
119 int i = 0;
120
121 while (i < work->len - 1) {
122 if (*ptr != 0x55)
123 break;
124 ptr++;
125 i++;
126 }
127
128 if (*ptr == 0xd5) {
129 /*
130 printk_ratelimited("Port %d received 0xd5 preamble\n",
131 work->ipprt);
132 */
133 work->packet_ptr.s.addr += i + 1;
134 work->len -= i + 5;
135 } else if ((*ptr & 0xf) == 0xd) {
136 /*
137 printk_ratelimited("Port %d received 0x?d preamble\n",
138 work->ipprt);
139 */
140 work->packet_ptr.s.addr += i;
141 work->len -= i + 4;
142 for (i = 0; i < work->len; i++) {
143 *ptr =
144 ((*ptr & 0xf0) >> 4) |
145 ((*(ptr + 1) & 0xf) << 4);
146 ptr++;
147 }
148 } else {
149 printk_ratelimited("Port %d unknown preamble, packet dropped\n",
150 work->ipprt);
151 /*
152 cvmx_helper_dump_packet(work);
153 */
154 cvm_oct_free_work(work);
155 return 1;
156 }
157 }
158 } else {
159 printk_ratelimited("Port %d receive error code %d, packet dropped\n",
160 work->ipprt, work->word2.snoip.err_code);
161 cvm_oct_free_work(work);
162 return 1;
163 }
164
165 return 0;
166 }
167
168 /**
169 * cvm_oct_napi_poll - the NAPI poll function.
170 * @napi: The NAPI instance, or null if called from cvm_oct_poll_controller
171 * @budget: Maximum number of packets to receive.
172 *
173 * Returns the number of packets processed.
174 */
cvm_oct_napi_poll(struct napi_struct * napi,int budget)175 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
176 {
177 const int coreid = cvmx_get_core_num();
178 uint64_t old_group_mask;
179 uint64_t old_scratch;
180 int rx_count = 0;
181 int did_work_request = 0;
182 int packet_not_copied;
183
184 /* Prefetch cvm_oct_device since we know we need it soon */
185 prefetch(cvm_oct_device);
186
187 if (USE_ASYNC_IOBDMA) {
188 /* Save scratch in case userspace is using it */
189 CVMX_SYNCIOBDMA;
190 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
191 }
192
193 /* Only allow work for our group (and preserve priorities) */
194 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
195 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
196 (old_group_mask & ~0xFFFFull) | 1 << pow_receive_group);
197
198 if (USE_ASYNC_IOBDMA) {
199 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
200 did_work_request = 1;
201 }
202
203 while (rx_count < budget) {
204 struct sk_buff *skb = NULL;
205 struct sk_buff **pskb = NULL;
206 int skb_in_hw;
207 cvmx_wqe_t *work;
208
209 if (USE_ASYNC_IOBDMA && did_work_request)
210 work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
211 else
212 work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
213
214 prefetch(work);
215 did_work_request = 0;
216 if (work == NULL) {
217 union cvmx_pow_wq_int wq_int;
218
219 wq_int.u64 = 0;
220 wq_int.s.iq_dis = 1 << pow_receive_group;
221 wq_int.s.wq_int = 1 << pow_receive_group;
222 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
223 break;
224 }
225 pskb = (struct sk_buff **)(cvm_oct_get_buffer_ptr(work->packet_ptr) -
226 sizeof(void *));
227 prefetch(pskb);
228
229 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
230 cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
231 CVMX_POW_NO_WAIT);
232 did_work_request = 1;
233 }
234 rx_count++;
235
236 skb_in_hw = USE_SKBUFFS_IN_HW && work->word2.s.bufs == 1;
237 if (likely(skb_in_hw)) {
238 skb = *pskb;
239 prefetch(&skb->head);
240 prefetch(&skb->len);
241 }
242 prefetch(cvm_oct_device[work->ipprt]);
243
244 /* Immediately throw away all packets with receive errors */
245 if (unlikely(work->word2.snoip.rcv_error)) {
246 if (cvm_oct_check_rcv_error(work))
247 continue;
248 }
249
250 /*
251 * We can only use the zero copy path if skbuffs are
252 * in the FPA pool and the packet fits in a single
253 * buffer.
254 */
255 if (likely(skb_in_hw)) {
256 skb->data = skb->head + work->packet_ptr.s.addr -
257 cvmx_ptr_to_phys(skb->head);
258 prefetch(skb->data);
259 skb->len = work->len;
260 skb_set_tail_pointer(skb, skb->len);
261 packet_not_copied = 1;
262 } else {
263 /*
264 * We have to copy the packet. First allocate
265 * an skbuff for it.
266 */
267 skb = dev_alloc_skb(work->len);
268 if (!skb) {
269 cvm_oct_free_work(work);
270 continue;
271 }
272
273 /*
274 * Check if we've received a packet that was
275 * entirely stored in the work entry.
276 */
277 if (unlikely(work->word2.s.bufs == 0)) {
278 uint8_t *ptr = work->packet_data;
279
280 if (likely(!work->word2.s.not_IP)) {
281 /*
282 * The beginning of the packet
283 * moves for IP packets.
284 */
285 if (work->word2.s.is_v6)
286 ptr += 2;
287 else
288 ptr += 6;
289 }
290 memcpy(skb_put(skb, work->len), ptr, work->len);
291 /* No packet buffers to free */
292 } else {
293 int segments = work->word2.s.bufs;
294 union cvmx_buf_ptr segment_ptr =
295 work->packet_ptr;
296 int len = work->len;
297
298 while (segments--) {
299 union cvmx_buf_ptr next_ptr =
300 *(union cvmx_buf_ptr *)cvmx_phys_to_ptr(segment_ptr.s.addr - 8);
301
302 /*
303 * Octeon Errata PKI-100: The segment size is
304 * wrong. Until it is fixed, calculate the
305 * segment size based on the packet pool
306 * buffer size. When it is fixed, the
307 * following line should be replaced with this
308 * one: int segment_size =
309 * segment_ptr.s.size;
310 */
311 int segment_size =
312 CVMX_FPA_PACKET_POOL_SIZE -
313 (segment_ptr.s.addr -
314 (((segment_ptr.s.addr >> 7) -
315 segment_ptr.s.back) << 7));
316 /*
317 * Don't copy more than what
318 * is left in the packet.
319 */
320 if (segment_size > len)
321 segment_size = len;
322 /* Copy the data into the packet */
323 memcpy(skb_put(skb, segment_size),
324 cvmx_phys_to_ptr(segment_ptr.s.addr),
325 segment_size);
326 len -= segment_size;
327 segment_ptr = next_ptr;
328 }
329 }
330 packet_not_copied = 0;
331 }
332
333 if (likely((work->ipprt < TOTAL_NUMBER_OF_PORTS) &&
334 cvm_oct_device[work->ipprt])) {
335 struct net_device *dev = cvm_oct_device[work->ipprt];
336 struct octeon_ethernet *priv = netdev_priv(dev);
337
338 /*
339 * Only accept packets for devices that are
340 * currently up.
341 */
342 if (likely(dev->flags & IFF_UP)) {
343 skb->protocol = eth_type_trans(skb, dev);
344 skb->dev = dev;
345
346 if (unlikely(work->word2.s.not_IP ||
347 work->word2.s.IP_exc ||
348 work->word2.s.L4_error ||
349 !work->word2.s.tcp_or_udp))
350 skb->ip_summed = CHECKSUM_NONE;
351 else
352 skb->ip_summed = CHECKSUM_UNNECESSARY;
353
354 /* Increment RX stats for virtual ports */
355 if (work->ipprt >= CVMX_PIP_NUM_INPUT_PORTS) {
356 #ifdef CONFIG_64BIT
357 atomic64_add(1,
358 (atomic64_t *)&priv->stats.rx_packets);
359 atomic64_add(skb->len,
360 (atomic64_t *)&priv->stats.rx_bytes);
361 #else
362 atomic_add(1,
363 (atomic_t *)&priv->stats.rx_packets);
364 atomic_add(skb->len,
365 (atomic_t *)&priv->stats.rx_bytes);
366 #endif
367 }
368 netif_receive_skb(skb);
369 } else {
370 /* Drop any packet received for a device that isn't up */
371 /*
372 printk_ratelimited("%s: Device not up, packet dropped\n",
373 dev->name);
374 */
375 #ifdef CONFIG_64BIT
376 atomic64_add(1,
377 (atomic64_t *)&priv->stats.rx_dropped);
378 #else
379 atomic_add(1,
380 (atomic_t *)&priv->stats.rx_dropped);
381 #endif
382 dev_kfree_skb_irq(skb);
383 }
384 } else {
385 /*
386 * Drop any packet received for a device that
387 * doesn't exist.
388 */
389 printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
390 work->ipprt);
391 dev_kfree_skb_irq(skb);
392 }
393 /*
394 * Check to see if the skbuff and work share the same
395 * packet buffer.
396 */
397 if (USE_SKBUFFS_IN_HW && likely(packet_not_copied)) {
398 /*
399 * This buffer needs to be replaced, increment
400 * the number of buffers we need to free by
401 * one.
402 */
403 cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
404 1);
405
406 cvmx_fpa_free(work, CVMX_FPA_WQE_POOL,
407 DONT_WRITEBACK(1));
408 } else {
409 cvm_oct_free_work(work);
410 }
411 }
412 /* Restore the original POW group mask */
413 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
414 if (USE_ASYNC_IOBDMA) {
415 /* Restore the scratch area */
416 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
417 }
418 cvm_oct_rx_refill_pool(0);
419
420 if (rx_count < budget && napi != NULL) {
421 /* No more work */
422 napi_complete(napi);
423 enable_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group);
424 }
425 return rx_count;
426 }
427
428 #ifdef CONFIG_NET_POLL_CONTROLLER
429 /**
430 * cvm_oct_poll_controller - poll for receive packets
431 * device.
432 *
433 * @dev: Device to poll. Unused
434 */
cvm_oct_poll_controller(struct net_device * dev)435 void cvm_oct_poll_controller(struct net_device *dev)
436 {
437 cvm_oct_napi_poll(NULL, 16);
438 }
439 #endif
440
cvm_oct_rx_initialize(void)441 void cvm_oct_rx_initialize(void)
442 {
443 int i;
444 struct net_device *dev_for_napi = NULL;
445 union cvmx_pow_wq_int_thrx int_thr;
446 union cvmx_pow_wq_int_pc int_pc;
447
448 for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
449 if (cvm_oct_device[i]) {
450 dev_for_napi = cvm_oct_device[i];
451 break;
452 }
453 }
454
455 if (NULL == dev_for_napi)
456 panic("No net_devices were allocated.");
457
458 netif_napi_add(dev_for_napi, &cvm_oct_napi, cvm_oct_napi_poll,
459 rx_napi_weight);
460 napi_enable(&cvm_oct_napi);
461
462 /* Register an IRQ handler to receive POW interrupts */
463 i = request_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group,
464 cvm_oct_do_interrupt, 0, "Ethernet", cvm_oct_device);
465
466 if (i)
467 panic("Could not acquire Ethernet IRQ %d\n",
468 OCTEON_IRQ_WORKQ0 + pow_receive_group);
469
470 disable_irq_nosync(OCTEON_IRQ_WORKQ0 + pow_receive_group);
471
472 int_thr.u64 = 0;
473 int_thr.s.tc_en = 1;
474 int_thr.s.tc_thr = 1;
475 /* Enable POW interrupt when our port has at least one packet */
476 cvmx_write_csr(CVMX_POW_WQ_INT_THRX(pow_receive_group), int_thr.u64);
477
478 int_pc.u64 = 0;
479 int_pc.s.pc_thr = 5;
480 cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
481
482 /* Schedule NAPI now. This will indirectly enable the interrupt. */
483 napi_schedule(&cvm_oct_napi);
484 }
485
cvm_oct_rx_shutdown(void)486 void cvm_oct_rx_shutdown(void)
487 {
488 netif_napi_del(&cvm_oct_napi);
489 }
490