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/netdevice.h>
30 #include <linux/init.h>
31 #include <linux/etherdevice.h>
32 #include <linux/ip.h>
33 #include <linux/ratelimit.h>
34 #include <linux/string.h>
35 #include <linux/interrupt.h>
36 #include <net/dst.h>
37 #ifdef CONFIG_XFRM
38 #include <linux/xfrm.h>
39 #include <net/xfrm.h>
40 #endif /* CONFIG_XFRM */
41 
42 #include <linux/atomic.h>
43 
44 #include <asm/octeon/octeon.h>
45 
46 #include "ethernet-defines.h"
47 #include "octeon-ethernet.h"
48 #include "ethernet-tx.h"
49 #include "ethernet-util.h"
50 
51 #include <asm/octeon/cvmx-wqe.h>
52 #include <asm/octeon/cvmx-fau.h>
53 #include <asm/octeon/cvmx-pip.h>
54 #include <asm/octeon/cvmx-pko.h>
55 #include <asm/octeon/cvmx-helper.h>
56 
57 #include <asm/octeon/cvmx-gmxx-defs.h>
58 
59 #define CVM_OCT_SKB_CB(skb)	((u64 *)((skb)->cb))
60 
61 /*
62  * You can define GET_SKBUFF_QOS() to override how the skbuff output
63  * function determines which output queue is used. The default
64  * implementation always uses the base queue for the port. If, for
65  * example, you wanted to use the skb->priority fieid, define
66  * GET_SKBUFF_QOS as: #define GET_SKBUFF_QOS(skb) ((skb)->priority)
67  */
68 #ifndef GET_SKBUFF_QOS
69 #define GET_SKBUFF_QOS(skb) 0
70 #endif
71 
72 static void cvm_oct_tx_do_cleanup(unsigned long arg);
73 static DECLARE_TASKLET(cvm_oct_tx_cleanup_tasklet, cvm_oct_tx_do_cleanup, 0);
74 
75 /* Maximum number of SKBs to try to free per xmit packet. */
76 #define MAX_SKB_TO_FREE (MAX_OUT_QUEUE_DEPTH * 2)
77 
cvm_oct_adjust_skb_to_free(int32_t skb_to_free,int fau)78 static inline int32_t cvm_oct_adjust_skb_to_free(int32_t skb_to_free, int fau)
79 {
80 	int32_t undo;
81 	undo = skb_to_free > 0 ? MAX_SKB_TO_FREE : skb_to_free + MAX_SKB_TO_FREE;
82 	if (undo > 0)
83 		cvmx_fau_atomic_add32(fau, -undo);
84 	skb_to_free = -skb_to_free > MAX_SKB_TO_FREE ? MAX_SKB_TO_FREE : -skb_to_free;
85 	return skb_to_free;
86 }
87 
cvm_oct_kick_tx_poll_watchdog(void)88 static void cvm_oct_kick_tx_poll_watchdog(void)
89 {
90 	union cvmx_ciu_timx ciu_timx;
91 	ciu_timx.u64 = 0;
92 	ciu_timx.s.one_shot = 1;
93 	ciu_timx.s.len = cvm_oct_tx_poll_interval;
94 	cvmx_write_csr(CVMX_CIU_TIMX(1), ciu_timx.u64);
95 }
96 
cvm_oct_free_tx_skbs(struct net_device * dev)97 void cvm_oct_free_tx_skbs(struct net_device *dev)
98 {
99 	int32_t skb_to_free;
100 	int qos, queues_per_port;
101 	int total_freed = 0;
102 	int total_remaining = 0;
103 	unsigned long flags;
104 	struct octeon_ethernet *priv = netdev_priv(dev);
105 
106 	queues_per_port = cvmx_pko_get_num_queues(priv->port);
107 	/* Drain any pending packets in the free list */
108 	for (qos = 0; qos < queues_per_port; qos++) {
109 		if (skb_queue_len(&priv->tx_free_list[qos]) == 0)
110 			continue;
111 		skb_to_free = cvmx_fau_fetch_and_add32(priv->fau+qos*4, MAX_SKB_TO_FREE);
112 		skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau+qos*4);
113 
114 
115 		total_freed += skb_to_free;
116 		if (skb_to_free > 0) {
117 			struct sk_buff *to_free_list = NULL;
118 			spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
119 			while (skb_to_free > 0) {
120 				struct sk_buff *t = __skb_dequeue(&priv->tx_free_list[qos]);
121 				t->next = to_free_list;
122 				to_free_list = t;
123 				skb_to_free--;
124 			}
125 			spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
126 			/* Do the actual freeing outside of the lock. */
127 			while (to_free_list) {
128 				struct sk_buff *t = to_free_list;
129 				to_free_list = to_free_list->next;
130 				dev_kfree_skb_any(t);
131 			}
132 		}
133 		total_remaining += skb_queue_len(&priv->tx_free_list[qos]);
134 	}
135 	if (total_freed >= 0 && netif_queue_stopped(dev))
136 		netif_wake_queue(dev);
137 	if (total_remaining)
138 		cvm_oct_kick_tx_poll_watchdog();
139 }
140 
141 /**
142  * cvm_oct_xmit - transmit a packet
143  * @skb:    Packet to send
144  * @dev:    Device info structure
145  *
146  * Returns Always returns NETDEV_TX_OK
147  */
cvm_oct_xmit(struct sk_buff * skb,struct net_device * dev)148 int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
149 {
150 	cvmx_pko_command_word0_t pko_command;
151 	union cvmx_buf_ptr hw_buffer;
152 	uint64_t old_scratch;
153 	uint64_t old_scratch2;
154 	int qos;
155 	int i;
156 	enum {QUEUE_CORE, QUEUE_HW, QUEUE_DROP} queue_type;
157 	struct octeon_ethernet *priv = netdev_priv(dev);
158 	struct sk_buff *to_free_list;
159 	int32_t skb_to_free;
160 	int32_t buffers_to_free;
161 	u32 total_to_clean;
162 	unsigned long flags;
163 #if REUSE_SKBUFFS_WITHOUT_FREE
164 	unsigned char *fpa_head;
165 #endif
166 
167 	/*
168 	 * Prefetch the private data structure.  It is larger that one
169 	 * cache line.
170 	 */
171 	prefetch(priv);
172 
173 	/*
174 	 * The check on CVMX_PKO_QUEUES_PER_PORT_* is designed to
175 	 * completely remove "qos" in the event neither interface
176 	 * supports multiple queues per port.
177 	 */
178 	if ((CVMX_PKO_QUEUES_PER_PORT_INTERFACE0 > 1) ||
179 	    (CVMX_PKO_QUEUES_PER_PORT_INTERFACE1 > 1)) {
180 		qos = GET_SKBUFF_QOS(skb);
181 		if (qos <= 0)
182 			qos = 0;
183 		else if (qos >= cvmx_pko_get_num_queues(priv->port))
184 			qos = 0;
185 	} else
186 		qos = 0;
187 
188 	if (USE_ASYNC_IOBDMA) {
189 		/* Save scratch in case userspace is using it */
190 		CVMX_SYNCIOBDMA;
191 		old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
192 		old_scratch2 = cvmx_scratch_read64(CVMX_SCR_SCRATCH + 8);
193 
194 		/*
195 		 * Fetch and increment the number of packets to be
196 		 * freed.
197 		 */
198 		cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH + 8,
199 					       FAU_NUM_PACKET_BUFFERS_TO_FREE,
200 					       0);
201 		cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH,
202 					       priv->fau + qos * 4,
203 					       MAX_SKB_TO_FREE);
204 	}
205 
206 	/*
207 	 * We have space for 6 segment pointers, If there will be more
208 	 * than that, we must linearize.
209 	 */
210 	if (unlikely(skb_shinfo(skb)->nr_frags > 5)) {
211 		if (unlikely(__skb_linearize(skb))) {
212 			queue_type = QUEUE_DROP;
213 			if (USE_ASYNC_IOBDMA) {
214 				/* Get the number of skbuffs in use by the hardware */
215 				CVMX_SYNCIOBDMA;
216 				skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
217 			} else {
218 				/* Get the number of skbuffs in use by the hardware */
219 				skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,
220 								       MAX_SKB_TO_FREE);
221 			}
222 			skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau + qos * 4);
223 			spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
224 			goto skip_xmit;
225 		}
226 	}
227 
228 	/*
229 	 * The CN3XXX series of parts has an errata (GMX-401) which
230 	 * causes the GMX block to hang if a collision occurs towards
231 	 * the end of a <68 byte packet. As a workaround for this, we
232 	 * pad packets to be 68 bytes whenever we are in half duplex
233 	 * mode. We don't handle the case of having a small packet but
234 	 * no room to add the padding.  The kernel should always give
235 	 * us at least a cache line
236 	 */
237 	if ((skb->len < 64) && OCTEON_IS_MODEL(OCTEON_CN3XXX)) {
238 		union cvmx_gmxx_prtx_cfg gmx_prt_cfg;
239 		int interface = INTERFACE(priv->port);
240 		int index = INDEX(priv->port);
241 
242 		if (interface < 2) {
243 			/* We only need to pad packet in half duplex mode */
244 			gmx_prt_cfg.u64 =
245 			    cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
246 			if (gmx_prt_cfg.s.duplex == 0) {
247 				int add_bytes = 64 - skb->len;
248 				if ((skb_tail_pointer(skb) + add_bytes) <=
249 				    skb_end_pointer(skb))
250 					memset(__skb_put(skb, add_bytes), 0,
251 					       add_bytes);
252 			}
253 		}
254 	}
255 
256 	/* Build the PKO command */
257 	pko_command.u64 = 0;
258 	pko_command.s.n2 = 1;	/* Don't pollute L2 with the outgoing packet */
259 	pko_command.s.segs = 1;
260 	pko_command.s.total_bytes = skb->len;
261 	pko_command.s.size0 = CVMX_FAU_OP_SIZE_32;
262 	pko_command.s.subone0 = 1;
263 
264 	pko_command.s.dontfree = 1;
265 
266 	/* Build the PKO buffer pointer */
267 	hw_buffer.u64 = 0;
268 	if (skb_shinfo(skb)->nr_frags == 0) {
269 		hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);
270 		hw_buffer.s.pool = 0;
271 		hw_buffer.s.size = skb->len;
272 	} else {
273 		hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);
274 		hw_buffer.s.pool = 0;
275 		hw_buffer.s.size = skb_headlen(skb);
276 		CVM_OCT_SKB_CB(skb)[0] = hw_buffer.u64;
277 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
278 			struct skb_frag_struct *fs = skb_shinfo(skb)->frags + i;
279 			hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)(page_address(fs->page.p) + fs->page_offset));
280 			hw_buffer.s.size = fs->size;
281 			CVM_OCT_SKB_CB(skb)[i + 1] = hw_buffer.u64;
282 		}
283 		hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)CVM_OCT_SKB_CB(skb));
284 		hw_buffer.s.size = skb_shinfo(skb)->nr_frags + 1;
285 		pko_command.s.segs = skb_shinfo(skb)->nr_frags + 1;
286 		pko_command.s.gather = 1;
287 		goto dont_put_skbuff_in_hw;
288 	}
289 
290 	/*
291 	 * See if we can put this skb in the FPA pool. Any strange
292 	 * behavior from the Linux networking stack will most likely
293 	 * be caused by a bug in the following code. If some field is
294 	 * in use by the network stack and get carried over when a
295 	 * buffer is reused, bad thing may happen.  If in doubt and
296 	 * you dont need the absolute best performance, disable the
297 	 * define REUSE_SKBUFFS_WITHOUT_FREE. The reuse of buffers has
298 	 * shown a 25% increase in performance under some loads.
299 	 */
300 #if REUSE_SKBUFFS_WITHOUT_FREE
301 	fpa_head = skb->head + 256 - ((unsigned long)skb->head & 0x7f);
302 	if (unlikely(skb->data < fpa_head)) {
303 		/*
304 		 * printk("TX buffer beginning can't meet FPA
305 		 * alignment constraints\n");
306 		 */
307 		goto dont_put_skbuff_in_hw;
308 	}
309 	if (unlikely
310 	    ((skb_end_pointer(skb) - fpa_head) < CVMX_FPA_PACKET_POOL_SIZE)) {
311 		/*
312 		   printk("TX buffer isn't large enough for the FPA\n");
313 		 */
314 		goto dont_put_skbuff_in_hw;
315 	}
316 	if (unlikely(skb_shared(skb))) {
317 		/*
318 		   printk("TX buffer sharing data with someone else\n");
319 		 */
320 		goto dont_put_skbuff_in_hw;
321 	}
322 	if (unlikely(skb_cloned(skb))) {
323 		/*
324 		   printk("TX buffer has been cloned\n");
325 		 */
326 		goto dont_put_skbuff_in_hw;
327 	}
328 	if (unlikely(skb_header_cloned(skb))) {
329 		/*
330 		   printk("TX buffer header has been cloned\n");
331 		 */
332 		goto dont_put_skbuff_in_hw;
333 	}
334 	if (unlikely(skb->destructor)) {
335 		/*
336 		   printk("TX buffer has a destructor\n");
337 		 */
338 		goto dont_put_skbuff_in_hw;
339 	}
340 	if (unlikely(skb_shinfo(skb)->nr_frags)) {
341 		/*
342 		   printk("TX buffer has fragments\n");
343 		 */
344 		goto dont_put_skbuff_in_hw;
345 	}
346 	if (unlikely
347 	    (skb->truesize !=
348 	     sizeof(*skb) + skb_end_offset(skb))) {
349 		/*
350 		   printk("TX buffer truesize has been changed\n");
351 		 */
352 		goto dont_put_skbuff_in_hw;
353 	}
354 
355 	/*
356 	 * We can use this buffer in the FPA.  We don't need the FAU
357 	 * update anymore
358 	 */
359 	pko_command.s.dontfree = 0;
360 
361 	hw_buffer.s.back = ((unsigned long)skb->data >> 7) - ((unsigned long)fpa_head >> 7);
362 	*(struct sk_buff **)(fpa_head - sizeof(void *)) = skb;
363 
364 	/*
365 	 * The skbuff will be reused without ever being freed. We must
366 	 * cleanup a bunch of core things.
367 	 */
368 	dst_release(skb_dst(skb));
369 	skb_dst_set(skb, NULL);
370 #ifdef CONFIG_XFRM
371 	secpath_put(skb->sp);
372 	skb->sp = NULL;
373 #endif
374 	nf_reset(skb);
375 
376 #ifdef CONFIG_NET_SCHED
377 	skb->tc_index = 0;
378 #ifdef CONFIG_NET_CLS_ACT
379 	skb->tc_verd = 0;
380 #endif /* CONFIG_NET_CLS_ACT */
381 #endif /* CONFIG_NET_SCHED */
382 #endif /* REUSE_SKBUFFS_WITHOUT_FREE */
383 
384 dont_put_skbuff_in_hw:
385 
386 	/* Check if we can use the hardware checksumming */
387 	if (USE_HW_TCPUDP_CHECKSUM && (skb->protocol == htons(ETH_P_IP)) &&
388 	    (ip_hdr(skb)->version == 4) && (ip_hdr(skb)->ihl == 5) &&
389 	    ((ip_hdr(skb)->frag_off == 0) || (ip_hdr(skb)->frag_off == 1 << 14))
390 	    && ((ip_hdr(skb)->protocol == IPPROTO_TCP)
391 		|| (ip_hdr(skb)->protocol == IPPROTO_UDP))) {
392 		/* Use hardware checksum calc */
393 		pko_command.s.ipoffp1 = sizeof(struct ethhdr) + 1;
394 	}
395 
396 	if (USE_ASYNC_IOBDMA) {
397 		/* Get the number of skbuffs in use by the hardware */
398 		CVMX_SYNCIOBDMA;
399 		skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
400 		buffers_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH + 8);
401 	} else {
402 		/* Get the number of skbuffs in use by the hardware */
403 		skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,
404 						       MAX_SKB_TO_FREE);
405 		buffers_to_free =
406 		    cvmx_fau_fetch_and_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, 0);
407 	}
408 
409 	skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau+qos*4);
410 
411 	/*
412 	 * If we're sending faster than the receive can free them then
413 	 * don't do the HW free.
414 	 */
415 	if ((buffers_to_free < -100) && !pko_command.s.dontfree)
416 		pko_command.s.dontfree = 1;
417 
418 	if (pko_command.s.dontfree) {
419 		queue_type = QUEUE_CORE;
420 		pko_command.s.reg0 = priv->fau+qos*4;
421 	} else {
422 		queue_type = QUEUE_HW;
423 	}
424 	if (USE_ASYNC_IOBDMA)
425 		cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH, FAU_TOTAL_TX_TO_CLEAN, 1);
426 
427 	spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
428 
429 	/* Drop this packet if we have too many already queued to the HW */
430 	if (unlikely(skb_queue_len(&priv->tx_free_list[qos]) >= MAX_OUT_QUEUE_DEPTH)) {
431 		if (dev->tx_queue_len != 0) {
432 			/* Drop the lock when notifying the core.  */
433 			spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
434 			netif_stop_queue(dev);
435 			spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
436 		} else {
437 			/* If not using normal queueing.  */
438 			queue_type = QUEUE_DROP;
439 			goto skip_xmit;
440 		}
441 	}
442 
443 	cvmx_pko_send_packet_prepare(priv->port, priv->queue + qos,
444 				     CVMX_PKO_LOCK_NONE);
445 
446 	/* Send the packet to the output queue */
447 	if (unlikely(cvmx_pko_send_packet_finish(priv->port,
448 						 priv->queue + qos,
449 						 pko_command, hw_buffer,
450 						 CVMX_PKO_LOCK_NONE))) {
451 		printk_ratelimited("%s: Failed to send the packet\n", dev->name);
452 		queue_type = QUEUE_DROP;
453 	}
454 skip_xmit:
455 	to_free_list = NULL;
456 
457 	switch (queue_type) {
458 	case QUEUE_DROP:
459 		skb->next = to_free_list;
460 		to_free_list = skb;
461 		priv->stats.tx_dropped++;
462 		break;
463 	case QUEUE_HW:
464 		cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, -1);
465 		break;
466 	case QUEUE_CORE:
467 		__skb_queue_tail(&priv->tx_free_list[qos], skb);
468 		break;
469 	default:
470 		BUG();
471 	}
472 
473 	while (skb_to_free > 0) {
474 		struct sk_buff *t = __skb_dequeue(&priv->tx_free_list[qos]);
475 		t->next = to_free_list;
476 		to_free_list = t;
477 		skb_to_free--;
478 	}
479 
480 	spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
481 
482 	/* Do the actual freeing outside of the lock. */
483 	while (to_free_list) {
484 		struct sk_buff *t = to_free_list;
485 		to_free_list = to_free_list->next;
486 		dev_kfree_skb_any(t);
487 	}
488 
489 	if (USE_ASYNC_IOBDMA) {
490 		CVMX_SYNCIOBDMA;
491 		total_to_clean = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
492 		/* Restore the scratch area */
493 		cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
494 		cvmx_scratch_write64(CVMX_SCR_SCRATCH + 8, old_scratch2);
495 	} else {
496 		total_to_clean = cvmx_fau_fetch_and_add32(FAU_TOTAL_TX_TO_CLEAN, 1);
497 	}
498 
499 	if (total_to_clean & 0x3ff) {
500 		/*
501 		 * Schedule the cleanup tasklet every 1024 packets for
502 		 * the pathological case of high traffic on one port
503 		 * delaying clean up of packets on a different port
504 		 * that is blocked waiting for the cleanup.
505 		 */
506 		tasklet_schedule(&cvm_oct_tx_cleanup_tasklet);
507 	}
508 
509 	cvm_oct_kick_tx_poll_watchdog();
510 
511 	return NETDEV_TX_OK;
512 }
513 
514 /**
515  * cvm_oct_xmit_pow - transmit a packet to the POW
516  * @skb:    Packet to send
517  * @dev:    Device info structure
518 
519  * Returns Always returns zero
520  */
cvm_oct_xmit_pow(struct sk_buff * skb,struct net_device * dev)521 int cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev)
522 {
523 	struct octeon_ethernet *priv = netdev_priv(dev);
524 	void *packet_buffer;
525 	void *copy_location;
526 
527 	/* Get a work queue entry */
528 	cvmx_wqe_t *work = cvmx_fpa_alloc(CVMX_FPA_WQE_POOL);
529 	if (unlikely(work == NULL)) {
530 		printk_ratelimited("%s: Failed to allocate a work "
531 				   "queue entry\n", dev->name);
532 		priv->stats.tx_dropped++;
533 		dev_kfree_skb(skb);
534 		return 0;
535 	}
536 
537 	/* Get a packet buffer */
538 	packet_buffer = cvmx_fpa_alloc(CVMX_FPA_PACKET_POOL);
539 	if (unlikely(packet_buffer == NULL)) {
540 		printk_ratelimited("%s: Failed to allocate a packet buffer\n",
541 				   dev->name);
542 		cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, DONT_WRITEBACK(1));
543 		priv->stats.tx_dropped++;
544 		dev_kfree_skb(skb);
545 		return 0;
546 	}
547 
548 	/*
549 	 * Calculate where we need to copy the data to. We need to
550 	 * leave 8 bytes for a next pointer (unused). We also need to
551 	 * include any configure skip. Then we need to align the IP
552 	 * packet src and dest into the same 64bit word. The below
553 	 * calculation may add a little extra, but that doesn't
554 	 * hurt.
555 	 */
556 	copy_location = packet_buffer + sizeof(uint64_t);
557 	copy_location += ((CVMX_HELPER_FIRST_MBUFF_SKIP + 7) & 0xfff8) + 6;
558 
559 	/*
560 	 * We have to copy the packet since whoever processes this
561 	 * packet will free it to a hardware pool. We can't use the
562 	 * trick of counting outstanding packets like in
563 	 * cvm_oct_xmit.
564 	 */
565 	memcpy(copy_location, skb->data, skb->len);
566 
567 	/*
568 	 * Fill in some of the work queue fields. We may need to add
569 	 * more if the software at the other end needs them.
570 	 */
571 	work->hw_chksum = skb->csum;
572 	work->len = skb->len;
573 	work->ipprt = priv->port;
574 	work->qos = priv->port & 0x7;
575 	work->grp = pow_send_group;
576 	work->tag_type = CVMX_HELPER_INPUT_TAG_TYPE;
577 	work->tag = pow_send_group;	/* FIXME */
578 	/* Default to zero. Sets of zero later are commented out */
579 	work->word2.u64 = 0;
580 	work->word2.s.bufs = 1;
581 	work->packet_ptr.u64 = 0;
582 	work->packet_ptr.s.addr = cvmx_ptr_to_phys(copy_location);
583 	work->packet_ptr.s.pool = CVMX_FPA_PACKET_POOL;
584 	work->packet_ptr.s.size = CVMX_FPA_PACKET_POOL_SIZE;
585 	work->packet_ptr.s.back = (copy_location - packet_buffer) >> 7;
586 
587 	if (skb->protocol == htons(ETH_P_IP)) {
588 		work->word2.s.ip_offset = 14;
589 #if 0
590 		work->word2.s.vlan_valid = 0;	/* FIXME */
591 		work->word2.s.vlan_cfi = 0;	/* FIXME */
592 		work->word2.s.vlan_id = 0;	/* FIXME */
593 		work->word2.s.dec_ipcomp = 0;	/* FIXME */
594 #endif
595 		work->word2.s.tcp_or_udp =
596 		    (ip_hdr(skb)->protocol == IPPROTO_TCP)
597 		    || (ip_hdr(skb)->protocol == IPPROTO_UDP);
598 #if 0
599 		/* FIXME */
600 		work->word2.s.dec_ipsec = 0;
601 		/* We only support IPv4 right now */
602 		work->word2.s.is_v6 = 0;
603 		/* Hardware would set to zero */
604 		work->word2.s.software = 0;
605 		/* No error, packet is internal */
606 		work->word2.s.L4_error = 0;
607 #endif
608 		work->word2.s.is_frag = !((ip_hdr(skb)->frag_off == 0)
609 					  || (ip_hdr(skb)->frag_off ==
610 					      1 << 14));
611 #if 0
612 		/* Assume Linux is sending a good packet */
613 		work->word2.s.IP_exc = 0;
614 #endif
615 		work->word2.s.is_bcast = (skb->pkt_type == PACKET_BROADCAST);
616 		work->word2.s.is_mcast = (skb->pkt_type == PACKET_MULTICAST);
617 #if 0
618 		/* This is an IP packet */
619 		work->word2.s.not_IP = 0;
620 		/* No error, packet is internal */
621 		work->word2.s.rcv_error = 0;
622 		/* No error, packet is internal */
623 		work->word2.s.err_code = 0;
624 #endif
625 
626 		/*
627 		 * When copying the data, include 4 bytes of the
628 		 * ethernet header to align the same way hardware
629 		 * does.
630 		 */
631 		memcpy(work->packet_data, skb->data + 10,
632 		       sizeof(work->packet_data));
633 	} else {
634 #if 0
635 		work->word2.snoip.vlan_valid = 0;	/* FIXME */
636 		work->word2.snoip.vlan_cfi = 0;	/* FIXME */
637 		work->word2.snoip.vlan_id = 0;	/* FIXME */
638 		work->word2.snoip.software = 0;	/* Hardware would set to zero */
639 #endif
640 		work->word2.snoip.is_rarp = skb->protocol == htons(ETH_P_RARP);
641 		work->word2.snoip.is_arp = skb->protocol == htons(ETH_P_ARP);
642 		work->word2.snoip.is_bcast =
643 		    (skb->pkt_type == PACKET_BROADCAST);
644 		work->word2.snoip.is_mcast =
645 		    (skb->pkt_type == PACKET_MULTICAST);
646 		work->word2.snoip.not_IP = 1;	/* IP was done up above */
647 #if 0
648 		/* No error, packet is internal */
649 		work->word2.snoip.rcv_error = 0;
650 		/* No error, packet is internal */
651 		work->word2.snoip.err_code = 0;
652 #endif
653 		memcpy(work->packet_data, skb->data, sizeof(work->packet_data));
654 	}
655 
656 	/* Submit the packet to the POW */
657 	cvmx_pow_work_submit(work, work->tag, work->tag_type, work->qos,
658 			     work->grp);
659 	priv->stats.tx_packets++;
660 	priv->stats.tx_bytes += skb->len;
661 	dev_kfree_skb(skb);
662 	return 0;
663 }
664 
665 /**
666  * cvm_oct_tx_shutdown_dev - free all skb that are currently queued for TX.
667  * @dev:    Device being shutdown
668  *
669  */
cvm_oct_tx_shutdown_dev(struct net_device * dev)670 void cvm_oct_tx_shutdown_dev(struct net_device *dev)
671 {
672 	struct octeon_ethernet *priv = netdev_priv(dev);
673 	unsigned long flags;
674 	int qos;
675 
676 	for (qos = 0; qos < 16; qos++) {
677 		spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
678 		while (skb_queue_len(&priv->tx_free_list[qos]))
679 			dev_kfree_skb_any(__skb_dequeue
680 					  (&priv->tx_free_list[qos]));
681 		spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
682 	}
683 }
684 
cvm_oct_tx_do_cleanup(unsigned long arg)685 static void cvm_oct_tx_do_cleanup(unsigned long arg)
686 {
687 	int port;
688 
689 	for (port = 0; port < TOTAL_NUMBER_OF_PORTS; port++) {
690 		if (cvm_oct_device[port]) {
691 			struct net_device *dev = cvm_oct_device[port];
692 			cvm_oct_free_tx_skbs(dev);
693 		}
694 	}
695 }
696 
cvm_oct_tx_cleanup_watchdog(int cpl,void * dev_id)697 static irqreturn_t cvm_oct_tx_cleanup_watchdog(int cpl, void *dev_id)
698 {
699 	/* Disable the interrupt.  */
700 	cvmx_write_csr(CVMX_CIU_TIMX(1), 0);
701 	/* Do the work in the tasklet.  */
702 	tasklet_schedule(&cvm_oct_tx_cleanup_tasklet);
703 	return IRQ_HANDLED;
704 }
705 
cvm_oct_tx_initialize(void)706 void cvm_oct_tx_initialize(void)
707 {
708 	int i;
709 
710 	/* Disable the interrupt.  */
711 	cvmx_write_csr(CVMX_CIU_TIMX(1), 0);
712 	/* Register an IRQ hander for to receive CIU_TIMX(1) interrupts */
713 	i = request_irq(OCTEON_IRQ_TIMER1,
714 			cvm_oct_tx_cleanup_watchdog, 0,
715 			"Ethernet", cvm_oct_device);
716 
717 	if (i)
718 		panic("Could not acquire Ethernet IRQ %d\n", OCTEON_IRQ_TIMER1);
719 }
720 
cvm_oct_tx_shutdown(void)721 void cvm_oct_tx_shutdown(void)
722 {
723 	/* Free the interrupt handler */
724 	free_irq(OCTEON_IRQ_TIMER1, cvm_oct_device);
725 }
726