xref: /linux/drivers/net/ethernet/cavium/liquidio/octeon_droq.c (revision 5c61f59824b5e46516ea5d0543ad7a8871567416)
1 /**********************************************************************
2  * Author: Cavium, Inc.
3  *
4  * Contact: support@cavium.com
5  *          Please include "LiquidIO" in the subject.
6  *
7  * Copyright (c) 2003-2016 Cavium, Inc.
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 details.
17  ***********************************************************************/
18 #include <linux/pci.h>
19 #include <linux/netdevice.h>
20 #include <linux/vmalloc.h>
21 #include "liquidio_common.h"
22 #include "octeon_droq.h"
23 #include "octeon_iq.h"
24 #include "response_manager.h"
25 #include "octeon_device.h"
26 #include "octeon_main.h"
27 #include "octeon_network.h"
28 #include "cn66xx_regs.h"
29 #include "cn66xx_device.h"
30 #include "cn23xx_pf_device.h"
31 #include "cn23xx_vf_device.h"
32 
33 struct __dispatch {
34 	struct list_head list;
35 	struct octeon_recv_info *rinfo;
36 	octeon_dispatch_fn_t disp_fn;
37 };
38 
39 /** Get the argument that the user set when registering dispatch
40  *  function for a given opcode/subcode.
41  *  @param  octeon_dev - the octeon device pointer.
42  *  @param  opcode     - the opcode for which the dispatch argument
43  *                       is to be checked.
44  *  @param  subcode    - the subcode for which the dispatch argument
45  *                       is to be checked.
46  *  @return  Success: void * (argument to the dispatch function)
47  *  @return  Failure: NULL
48  *
49  */
50 void *octeon_get_dispatch_arg(struct octeon_device *octeon_dev,
51 			      u16 opcode, u16 subcode)
52 {
53 	int idx;
54 	struct list_head *dispatch;
55 	void *fn_arg = NULL;
56 	u16 combined_opcode = OPCODE_SUBCODE(opcode, subcode);
57 
58 	idx = combined_opcode & OCTEON_OPCODE_MASK;
59 
60 	spin_lock_bh(&octeon_dev->dispatch.lock);
61 
62 	if (octeon_dev->dispatch.count == 0) {
63 		spin_unlock_bh(&octeon_dev->dispatch.lock);
64 		return NULL;
65 	}
66 
67 	if (octeon_dev->dispatch.dlist[idx].opcode == combined_opcode) {
68 		fn_arg = octeon_dev->dispatch.dlist[idx].arg;
69 	} else {
70 		list_for_each(dispatch,
71 			      &octeon_dev->dispatch.dlist[idx].list) {
72 			if (((struct octeon_dispatch *)dispatch)->opcode ==
73 			    combined_opcode) {
74 				fn_arg = ((struct octeon_dispatch *)
75 					  dispatch)->arg;
76 				break;
77 			}
78 		}
79 	}
80 
81 	spin_unlock_bh(&octeon_dev->dispatch.lock);
82 	return fn_arg;
83 }
84 
85 /** Check for packets on Droq. This function should be called with lock held.
86  *  @param  droq - Droq on which count is checked.
87  *  @return Returns packet count.
88  */
89 u32 octeon_droq_check_hw_for_pkts(struct octeon_droq *droq)
90 {
91 	u32 pkt_count = 0;
92 	u32 last_count;
93 
94 	pkt_count = readl(droq->pkts_sent_reg);
95 
96 	last_count = pkt_count - droq->pkt_count;
97 	droq->pkt_count = pkt_count;
98 
99 	/* we shall write to cnts  at napi irq enable or end of droq tasklet */
100 	if (last_count)
101 		atomic_add(last_count, &droq->pkts_pending);
102 
103 	return last_count;
104 }
105 EXPORT_SYMBOL_GPL(octeon_droq_check_hw_for_pkts);
106 
107 static void octeon_droq_compute_max_packet_bufs(struct octeon_droq *droq)
108 {
109 	u32 count = 0;
110 
111 	/* max_empty_descs is the max. no. of descs that can have no buffers.
112 	 * If the empty desc count goes beyond this value, we cannot safely
113 	 * read in a 64K packet sent by Octeon
114 	 * (64K is max pkt size from Octeon)
115 	 */
116 	droq->max_empty_descs = 0;
117 
118 	do {
119 		droq->max_empty_descs++;
120 		count += droq->buffer_size;
121 	} while (count < (64 * 1024));
122 
123 	droq->max_empty_descs = droq->max_count - droq->max_empty_descs;
124 }
125 
126 static void octeon_droq_reset_indices(struct octeon_droq *droq)
127 {
128 	droq->read_idx = 0;
129 	droq->write_idx = 0;
130 	droq->refill_idx = 0;
131 	droq->refill_count = 0;
132 	atomic_set(&droq->pkts_pending, 0);
133 }
134 
135 static void
136 octeon_droq_destroy_ring_buffers(struct octeon_device *oct,
137 				 struct octeon_droq *droq)
138 {
139 	u32 i;
140 	struct octeon_skb_page_info *pg_info;
141 
142 	for (i = 0; i < droq->max_count; i++) {
143 		pg_info = &droq->recv_buf_list[i].pg_info;
144 		if (!pg_info)
145 			continue;
146 
147 		if (pg_info->dma)
148 			lio_unmap_ring(oct->pci_dev,
149 				       (u64)pg_info->dma);
150 		pg_info->dma = 0;
151 
152 		if (pg_info->page)
153 			recv_buffer_destroy(droq->recv_buf_list[i].buffer,
154 					    pg_info);
155 
156 		droq->recv_buf_list[i].buffer = NULL;
157 	}
158 
159 	octeon_droq_reset_indices(droq);
160 }
161 
162 static int
163 octeon_droq_setup_ring_buffers(struct octeon_device *oct,
164 			       struct octeon_droq *droq)
165 {
166 	u32 i;
167 	void *buf;
168 	struct octeon_droq_desc *desc_ring = droq->desc_ring;
169 
170 	for (i = 0; i < droq->max_count; i++) {
171 		buf = recv_buffer_alloc(oct, &droq->recv_buf_list[i].pg_info);
172 
173 		if (!buf) {
174 			dev_err(&oct->pci_dev->dev, "%s buffer alloc failed\n",
175 				__func__);
176 			droq->stats.rx_alloc_failure++;
177 			return -ENOMEM;
178 		}
179 
180 		droq->recv_buf_list[i].buffer = buf;
181 		droq->recv_buf_list[i].data = get_rbd(buf);
182 		desc_ring[i].info_ptr = 0;
183 		desc_ring[i].buffer_ptr =
184 			lio_map_ring(droq->recv_buf_list[i].buffer);
185 	}
186 
187 	octeon_droq_reset_indices(droq);
188 
189 	octeon_droq_compute_max_packet_bufs(droq);
190 
191 	return 0;
192 }
193 
194 int octeon_delete_droq(struct octeon_device *oct, u32 q_no)
195 {
196 	struct octeon_droq *droq = oct->droq[q_no];
197 
198 	dev_dbg(&oct->pci_dev->dev, "%s[%d]\n", __func__, q_no);
199 
200 	octeon_droq_destroy_ring_buffers(oct, droq);
201 	vfree(droq->recv_buf_list);
202 
203 	if (droq->desc_ring)
204 		lio_dma_free(oct, (droq->max_count * OCT_DROQ_DESC_SIZE),
205 			     droq->desc_ring, droq->desc_ring_dma);
206 
207 	memset(droq, 0, OCT_DROQ_SIZE);
208 	oct->io_qmask.oq &= ~(1ULL << q_no);
209 	vfree(oct->droq[q_no]);
210 	oct->droq[q_no] = NULL;
211 	oct->num_oqs--;
212 
213 	return 0;
214 }
215 EXPORT_SYMBOL_GPL(octeon_delete_droq);
216 
217 int octeon_init_droq(struct octeon_device *oct,
218 		     u32 q_no,
219 		     u32 num_descs,
220 		     u32 desc_size,
221 		     void *app_ctx)
222 {
223 	struct octeon_droq *droq;
224 	u32 desc_ring_size = 0, c_num_descs = 0, c_buf_size = 0;
225 	u32 c_pkts_per_intr = 0, c_refill_threshold = 0;
226 	int numa_node = dev_to_node(&oct->pci_dev->dev);
227 
228 	dev_dbg(&oct->pci_dev->dev, "%s[%d]\n", __func__, q_no);
229 
230 	droq = oct->droq[q_no];
231 	memset(droq, 0, OCT_DROQ_SIZE);
232 
233 	droq->oct_dev = oct;
234 	droq->q_no = q_no;
235 	if (app_ctx)
236 		droq->app_ctx = app_ctx;
237 	else
238 		droq->app_ctx = (void *)(size_t)q_no;
239 
240 	c_num_descs = num_descs;
241 	c_buf_size = desc_size;
242 	if (OCTEON_CN6XXX(oct)) {
243 		struct octeon_config *conf6x = CHIP_CONF(oct, cn6xxx);
244 
245 		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf6x);
246 		c_refill_threshold =
247 			(u32)CFG_GET_OQ_REFILL_THRESHOLD(conf6x);
248 	} else if (OCTEON_CN23XX_PF(oct)) {
249 		struct octeon_config *conf23 = CHIP_CONF(oct, cn23xx_pf);
250 
251 		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf23);
252 		c_refill_threshold = (u32)CFG_GET_OQ_REFILL_THRESHOLD(conf23);
253 	} else if (OCTEON_CN23XX_VF(oct)) {
254 		struct octeon_config *conf23 = CHIP_CONF(oct, cn23xx_vf);
255 
256 		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf23);
257 		c_refill_threshold = (u32)CFG_GET_OQ_REFILL_THRESHOLD(conf23);
258 	} else {
259 		return 1;
260 	}
261 
262 	droq->max_count = c_num_descs;
263 	droq->buffer_size = c_buf_size;
264 
265 	desc_ring_size = droq->max_count * OCT_DROQ_DESC_SIZE;
266 	droq->desc_ring = lio_dma_alloc(oct, desc_ring_size,
267 					(dma_addr_t *)&droq->desc_ring_dma);
268 
269 	if (!droq->desc_ring) {
270 		dev_err(&oct->pci_dev->dev,
271 			"Output queue %d ring alloc failed\n", q_no);
272 		return 1;
273 	}
274 
275 	dev_dbg(&oct->pci_dev->dev, "droq[%d]: desc_ring: virt: 0x%p, dma: %lx\n",
276 		q_no, droq->desc_ring, droq->desc_ring_dma);
277 	dev_dbg(&oct->pci_dev->dev, "droq[%d]: num_desc: %d\n", q_no,
278 		droq->max_count);
279 
280 	droq->recv_buf_list = vzalloc_node(array_size(droq->max_count, OCT_DROQ_RECVBUF_SIZE),
281 					   numa_node);
282 	if (!droq->recv_buf_list)
283 		droq->recv_buf_list = vzalloc(array_size(droq->max_count, OCT_DROQ_RECVBUF_SIZE));
284 	if (!droq->recv_buf_list) {
285 		dev_err(&oct->pci_dev->dev, "Output queue recv buf list alloc failed\n");
286 		goto init_droq_fail;
287 	}
288 
289 	if (octeon_droq_setup_ring_buffers(oct, droq))
290 		goto init_droq_fail;
291 
292 	droq->pkts_per_intr = c_pkts_per_intr;
293 	droq->refill_threshold = c_refill_threshold;
294 
295 	dev_dbg(&oct->pci_dev->dev, "DROQ INIT: max_empty_descs: %d\n",
296 		droq->max_empty_descs);
297 
298 	INIT_LIST_HEAD(&droq->dispatch_list);
299 
300 	/* For 56xx Pass1, this function won't be called, so no checks. */
301 	oct->fn_list.setup_oq_regs(oct, q_no);
302 
303 	oct->io_qmask.oq |= BIT_ULL(q_no);
304 
305 	return 0;
306 
307 init_droq_fail:
308 	octeon_delete_droq(oct, q_no);
309 	return 1;
310 }
311 
312 /* octeon_create_recv_info
313  * Parameters:
314  *  octeon_dev - pointer to the octeon device structure
315  *  droq       - droq in which the packet arrived.
316  *  buf_cnt    - no. of buffers used by the packet.
317  *  idx        - index in the descriptor for the first buffer in the packet.
318  * Description:
319  *  Allocates a recv_info_t and copies the buffer addresses for packet data
320  *  into the recv_pkt space which starts at an 8B offset from recv_info_t.
321  *  Flags the descriptors for refill later. If available descriptors go
322  *  below the threshold to receive a 64K pkt, new buffers are first allocated
323  *  before the recv_pkt_t is created.
324  *  This routine will be called in interrupt context.
325  * Returns:
326  *  Success: Pointer to recv_info_t
327  *  Failure: NULL.
328  */
329 static inline struct octeon_recv_info *octeon_create_recv_info(
330 		struct octeon_device *octeon_dev,
331 		struct octeon_droq *droq,
332 		u32 buf_cnt,
333 		u32 idx)
334 {
335 	struct octeon_droq_info *info;
336 	struct octeon_recv_pkt *recv_pkt;
337 	struct octeon_recv_info *recv_info;
338 	u32 i, bytes_left;
339 	struct octeon_skb_page_info *pg_info;
340 
341 	info = (struct octeon_droq_info *)droq->recv_buf_list[idx].data;
342 
343 	recv_info = octeon_alloc_recv_info(sizeof(struct __dispatch));
344 	if (!recv_info)
345 		return NULL;
346 
347 	recv_pkt = recv_info->recv_pkt;
348 	recv_pkt->rh = info->rh;
349 	recv_pkt->length = (u32)info->length;
350 	recv_pkt->buffer_count = (u16)buf_cnt;
351 	recv_pkt->octeon_id = (u16)octeon_dev->octeon_id;
352 
353 	i = 0;
354 	bytes_left = (u32)info->length;
355 
356 	while (buf_cnt) {
357 		{
358 			pg_info = &droq->recv_buf_list[idx].pg_info;
359 
360 			lio_unmap_ring(octeon_dev->pci_dev,
361 				       (u64)pg_info->dma);
362 			pg_info->page = NULL;
363 			pg_info->dma = 0;
364 		}
365 
366 		recv_pkt->buffer_size[i] =
367 			(bytes_left >=
368 			 droq->buffer_size) ? droq->buffer_size : bytes_left;
369 
370 		recv_pkt->buffer_ptr[i] = droq->recv_buf_list[idx].buffer;
371 		droq->recv_buf_list[idx].buffer = NULL;
372 
373 		idx = incr_index(idx, 1, droq->max_count);
374 		bytes_left -= droq->buffer_size;
375 		i++;
376 		buf_cnt--;
377 	}
378 
379 	return recv_info;
380 }
381 
382 /* If we were not able to refill all buffers, try to move around
383  * the buffers that were not dispatched.
384  */
385 static inline u32
386 octeon_droq_refill_pullup_descs(struct octeon_droq *droq,
387 				struct octeon_droq_desc *desc_ring)
388 {
389 	u32 desc_refilled = 0;
390 
391 	u32 refill_index = droq->refill_idx;
392 
393 	while (refill_index != droq->read_idx) {
394 		if (droq->recv_buf_list[refill_index].buffer) {
395 			droq->recv_buf_list[droq->refill_idx].buffer =
396 				droq->recv_buf_list[refill_index].buffer;
397 			droq->recv_buf_list[droq->refill_idx].data =
398 				droq->recv_buf_list[refill_index].data;
399 			desc_ring[droq->refill_idx].buffer_ptr =
400 				desc_ring[refill_index].buffer_ptr;
401 			droq->recv_buf_list[refill_index].buffer = NULL;
402 			desc_ring[refill_index].buffer_ptr = 0;
403 			do {
404 				droq->refill_idx = incr_index(droq->refill_idx,
405 							      1,
406 							      droq->max_count);
407 				desc_refilled++;
408 				droq->refill_count--;
409 			} while (droq->recv_buf_list[droq->refill_idx].buffer);
410 		}
411 		refill_index = incr_index(refill_index, 1, droq->max_count);
412 	}                       /* while */
413 	return desc_refilled;
414 }
415 
416 /* octeon_droq_refill
417  * Parameters:
418  *  droq       - droq in which descriptors require new buffers.
419  * Description:
420  *  Called during normal DROQ processing in interrupt mode or by the poll
421  *  thread to refill the descriptors from which buffers were dispatched
422  *  to upper layers. Attempts to allocate new buffers. If that fails, moves
423  *  up buffers (that were not dispatched) to form a contiguous ring.
424  * Returns:
425  *  No of descriptors refilled.
426  */
427 static u32
428 octeon_droq_refill(struct octeon_device *octeon_dev, struct octeon_droq *droq)
429 {
430 	struct octeon_droq_desc *desc_ring;
431 	void *buf = NULL;
432 	u8 *data;
433 	u32 desc_refilled = 0;
434 	struct octeon_skb_page_info *pg_info;
435 
436 	desc_ring = droq->desc_ring;
437 
438 	while (droq->refill_count && (desc_refilled < droq->max_count)) {
439 		/* If a valid buffer exists (happens if there is no dispatch),
440 		 * reuse the buffer, else allocate.
441 		 */
442 		if (!droq->recv_buf_list[droq->refill_idx].buffer) {
443 			pg_info =
444 				&droq->recv_buf_list[droq->refill_idx].pg_info;
445 			/* Either recycle the existing pages or go for
446 			 * new page alloc
447 			 */
448 			if (pg_info->page)
449 				buf = recv_buffer_reuse(octeon_dev, pg_info);
450 			else
451 				buf = recv_buffer_alloc(octeon_dev, pg_info);
452 			/* If a buffer could not be allocated, no point in
453 			 * continuing
454 			 */
455 			if (!buf) {
456 				droq->stats.rx_alloc_failure++;
457 				break;
458 			}
459 			droq->recv_buf_list[droq->refill_idx].buffer =
460 				buf;
461 			data = get_rbd(buf);
462 		} else {
463 			data = get_rbd(droq->recv_buf_list
464 				       [droq->refill_idx].buffer);
465 		}
466 
467 		droq->recv_buf_list[droq->refill_idx].data = data;
468 
469 		desc_ring[droq->refill_idx].buffer_ptr =
470 			lio_map_ring(droq->recv_buf_list[
471 				     droq->refill_idx].buffer);
472 
473 		droq->refill_idx = incr_index(droq->refill_idx, 1,
474 					      droq->max_count);
475 		desc_refilled++;
476 		droq->refill_count--;
477 	}
478 
479 	if (droq->refill_count)
480 		desc_refilled +=
481 			octeon_droq_refill_pullup_descs(droq, desc_ring);
482 
483 	/* if droq->refill_count
484 	 * The refill count would not change in pass two. We only moved buffers
485 	 * to close the gap in the ring, but we would still have the same no. of
486 	 * buffers to refill.
487 	 */
488 	return desc_refilled;
489 }
490 
491 /** check if we can allocate packets to get out of oom.
492  *  @param  droq - Droq being checked.
493  *  @return 1 if fails to refill minimum
494  */
495 int octeon_retry_droq_refill(struct octeon_droq *droq)
496 {
497 	struct octeon_device *oct = droq->oct_dev;
498 	int desc_refilled, reschedule = 1;
499 	u32 pkts_credit;
500 
501 	pkts_credit = readl(droq->pkts_credit_reg);
502 	desc_refilled = octeon_droq_refill(oct, droq);
503 	if (desc_refilled) {
504 		/* Flush the droq descriptor data to memory to be sure
505 		 * that when we update the credits the data in memory
506 		 * is accurate.
507 		 */
508 		wmb();
509 		writel(desc_refilled, droq->pkts_credit_reg);
510 
511 		if (pkts_credit + desc_refilled >= CN23XX_SLI_DEF_BP)
512 			reschedule = 0;
513 	}
514 
515 	return reschedule;
516 }
517 
518 static inline u32
519 octeon_droq_get_bufcount(u32 buf_size, u32 total_len)
520 {
521 	return DIV_ROUND_UP(total_len, buf_size);
522 }
523 
524 static int
525 octeon_droq_dispatch_pkt(struct octeon_device *oct,
526 			 struct octeon_droq *droq,
527 			 union octeon_rh *rh,
528 			 struct octeon_droq_info *info)
529 {
530 	u32 cnt;
531 	octeon_dispatch_fn_t disp_fn;
532 	struct octeon_recv_info *rinfo;
533 
534 	cnt = octeon_droq_get_bufcount(droq->buffer_size, (u32)info->length);
535 
536 	disp_fn = octeon_get_dispatch(oct, (u16)rh->r.opcode,
537 				      (u16)rh->r.subcode);
538 	if (disp_fn) {
539 		rinfo = octeon_create_recv_info(oct, droq, cnt, droq->read_idx);
540 		if (rinfo) {
541 			struct __dispatch *rdisp = rinfo->rsvd;
542 
543 			rdisp->rinfo = rinfo;
544 			rdisp->disp_fn = disp_fn;
545 			rinfo->recv_pkt->rh = *rh;
546 			list_add_tail(&rdisp->list,
547 				      &droq->dispatch_list);
548 		} else {
549 			droq->stats.dropped_nomem++;
550 		}
551 	} else {
552 		dev_err(&oct->pci_dev->dev, "DROQ: No dispatch function (opcode %u/%u)\n",
553 			(unsigned int)rh->r.opcode,
554 			(unsigned int)rh->r.subcode);
555 		droq->stats.dropped_nodispatch++;
556 	}
557 
558 	return cnt;
559 }
560 
561 static inline void octeon_droq_drop_packets(struct octeon_device *oct,
562 					    struct octeon_droq *droq,
563 					    u32 cnt)
564 {
565 	u32 i = 0, buf_cnt;
566 	struct octeon_droq_info *info;
567 
568 	for (i = 0; i < cnt; i++) {
569 		info = (struct octeon_droq_info *)
570 			droq->recv_buf_list[droq->read_idx].data;
571 		octeon_swap_8B_data((u64 *)info, 2);
572 
573 		if (info->length) {
574 			info->length += OCTNET_FRM_LENGTH_SIZE;
575 			droq->stats.bytes_received += info->length;
576 			buf_cnt = octeon_droq_get_bufcount(droq->buffer_size,
577 							   (u32)info->length);
578 		} else {
579 			dev_err(&oct->pci_dev->dev, "DROQ: In drop: pkt with len 0\n");
580 			buf_cnt = 1;
581 		}
582 
583 		droq->read_idx = incr_index(droq->read_idx, buf_cnt,
584 					    droq->max_count);
585 		droq->refill_count += buf_cnt;
586 	}
587 }
588 
589 static u32
590 octeon_droq_fast_process_packets(struct octeon_device *oct,
591 				 struct octeon_droq *droq,
592 				 u32 pkts_to_process)
593 {
594 	u32 pkt, total_len = 0, pkt_count, retval;
595 	struct octeon_droq_info *info;
596 	union octeon_rh *rh;
597 
598 	pkt_count = pkts_to_process;
599 
600 	for (pkt = 0; pkt < pkt_count; pkt++) {
601 		u32 pkt_len = 0;
602 		struct sk_buff *nicbuf = NULL;
603 		struct octeon_skb_page_info *pg_info;
604 		void *buf;
605 
606 		info = (struct octeon_droq_info *)
607 			droq->recv_buf_list[droq->read_idx].data;
608 		octeon_swap_8B_data((u64 *)info, 2);
609 
610 		if (!info->length) {
611 			dev_err(&oct->pci_dev->dev,
612 				"DROQ[%d] idx: %d len:0, pkt_cnt: %d\n",
613 				droq->q_no, droq->read_idx, pkt_count);
614 			print_hex_dump_bytes("", DUMP_PREFIX_ADDRESS,
615 					     (u8 *)info,
616 					     OCT_DROQ_INFO_SIZE);
617 			break;
618 		}
619 
620 		/* Len of resp hdr in included in the received data len. */
621 		rh = &info->rh;
622 
623 		info->length += OCTNET_FRM_LENGTH_SIZE;
624 		rh->r_dh.len += (ROUNDUP8(OCT_DROQ_INFO_SIZE) / sizeof(u64));
625 		total_len += (u32)info->length;
626 		if (opcode_slow_path(rh)) {
627 			u32 buf_cnt;
628 
629 			buf_cnt = octeon_droq_dispatch_pkt(oct, droq, rh, info);
630 			droq->read_idx = incr_index(droq->read_idx,
631 						    buf_cnt, droq->max_count);
632 			droq->refill_count += buf_cnt;
633 		} else {
634 			if (info->length <= droq->buffer_size) {
635 				pkt_len = (u32)info->length;
636 				nicbuf = droq->recv_buf_list[
637 					droq->read_idx].buffer;
638 				pg_info = &droq->recv_buf_list[
639 					droq->read_idx].pg_info;
640 				if (recv_buffer_recycle(oct, pg_info))
641 					pg_info->page = NULL;
642 				droq->recv_buf_list[droq->read_idx].buffer =
643 					NULL;
644 
645 				droq->read_idx = incr_index(droq->read_idx, 1,
646 							    droq->max_count);
647 				droq->refill_count++;
648 			} else {
649 				nicbuf = octeon_fast_packet_alloc((u32)
650 								  info->length);
651 				pkt_len = 0;
652 				/* nicbuf allocation can fail. We'll handle it
653 				 * inside the loop.
654 				 */
655 				while (pkt_len < info->length) {
656 					int cpy_len, idx = droq->read_idx;
657 
658 					cpy_len = ((pkt_len + droq->buffer_size)
659 						   > info->length) ?
660 						((u32)info->length - pkt_len) :
661 						droq->buffer_size;
662 
663 					if (nicbuf) {
664 						octeon_fast_packet_next(droq,
665 									nicbuf,
666 									cpy_len,
667 									idx);
668 						buf = droq->recv_buf_list[
669 							idx].buffer;
670 						recv_buffer_fast_free(buf);
671 						droq->recv_buf_list[idx].buffer
672 							= NULL;
673 					} else {
674 						droq->stats.rx_alloc_failure++;
675 					}
676 
677 					pkt_len += cpy_len;
678 					droq->read_idx =
679 						incr_index(droq->read_idx, 1,
680 							   droq->max_count);
681 					droq->refill_count++;
682 				}
683 			}
684 
685 			if (nicbuf) {
686 				if (droq->ops.fptr) {
687 					droq->ops.fptr(oct->octeon_id,
688 						       nicbuf, pkt_len,
689 						       rh, &droq->napi,
690 						       droq->ops.farg);
691 				} else {
692 					recv_buffer_free(nicbuf);
693 				}
694 			}
695 		}
696 
697 		if (droq->refill_count >= droq->refill_threshold) {
698 			int desc_refilled = octeon_droq_refill(oct, droq);
699 
700 			if (desc_refilled) {
701 				/* Flush the droq descriptor data to memory to
702 				 * be sure that when we update the credits the
703 				 * data in memory is accurate.
704 				 */
705 				wmb();
706 				writel(desc_refilled, droq->pkts_credit_reg);
707 			}
708 		}
709 	}                       /* for (each packet)... */
710 
711 	/* Increment refill_count by the number of buffers processed. */
712 	droq->stats.pkts_received += pkt;
713 	droq->stats.bytes_received += total_len;
714 
715 	retval = pkt;
716 	if ((droq->ops.drop_on_max) && (pkts_to_process - pkt)) {
717 		octeon_droq_drop_packets(oct, droq, (pkts_to_process - pkt));
718 
719 		droq->stats.dropped_toomany += (pkts_to_process - pkt);
720 		retval = pkts_to_process;
721 	}
722 
723 	atomic_sub(retval, &droq->pkts_pending);
724 
725 	if (droq->refill_count >= droq->refill_threshold &&
726 	    readl(droq->pkts_credit_reg) < CN23XX_SLI_DEF_BP) {
727 		octeon_droq_check_hw_for_pkts(droq);
728 
729 		/* Make sure there are no pkts_pending */
730 		if (!atomic_read(&droq->pkts_pending))
731 			octeon_schedule_rxq_oom_work(oct, droq);
732 	}
733 
734 	return retval;
735 }
736 
737 int
738 octeon_droq_process_packets(struct octeon_device *oct,
739 			    struct octeon_droq *droq,
740 			    u32 budget)
741 {
742 	u32 pkt_count = 0;
743 	struct list_head *tmp, *tmp2;
744 
745 	octeon_droq_check_hw_for_pkts(droq);
746 	pkt_count = atomic_read(&droq->pkts_pending);
747 
748 	if (!pkt_count)
749 		return 0;
750 
751 	if (pkt_count > budget)
752 		pkt_count = budget;
753 
754 	octeon_droq_fast_process_packets(oct, droq, pkt_count);
755 
756 	list_for_each_safe(tmp, tmp2, &droq->dispatch_list) {
757 		struct __dispatch *rdisp = (struct __dispatch *)tmp;
758 
759 		list_del(tmp);
760 		rdisp->disp_fn(rdisp->rinfo,
761 			       octeon_get_dispatch_arg
762 			       (oct,
763 				(u16)rdisp->rinfo->recv_pkt->rh.r.opcode,
764 				(u16)rdisp->rinfo->recv_pkt->rh.r.subcode));
765 	}
766 
767 	/* If there are packets pending. schedule tasklet again */
768 	if (atomic_read(&droq->pkts_pending))
769 		return 1;
770 
771 	return 0;
772 }
773 EXPORT_SYMBOL_GPL(octeon_droq_process_packets);
774 
775 /*
776  * Utility function to poll for packets. check_hw_for_packets must be
777  * called before calling this routine.
778  */
779 
780 int
781 octeon_droq_process_poll_pkts(struct octeon_device *oct,
782 			      struct octeon_droq *droq, u32 budget)
783 {
784 	struct list_head *tmp, *tmp2;
785 	u32 pkts_available = 0, pkts_processed = 0;
786 	u32 total_pkts_processed = 0;
787 
788 	if (budget > droq->max_count)
789 		budget = droq->max_count;
790 
791 	while (total_pkts_processed < budget) {
792 		octeon_droq_check_hw_for_pkts(droq);
793 
794 		pkts_available = min((budget - total_pkts_processed),
795 				     (u32)(atomic_read(&droq->pkts_pending)));
796 
797 		if (pkts_available == 0)
798 			break;
799 
800 		pkts_processed =
801 			octeon_droq_fast_process_packets(oct, droq,
802 							 pkts_available);
803 
804 		total_pkts_processed += pkts_processed;
805 	}
806 
807 	list_for_each_safe(tmp, tmp2, &droq->dispatch_list) {
808 		struct __dispatch *rdisp = (struct __dispatch *)tmp;
809 
810 		list_del(tmp);
811 		rdisp->disp_fn(rdisp->rinfo,
812 			       octeon_get_dispatch_arg
813 			       (oct,
814 				(u16)rdisp->rinfo->recv_pkt->rh.r.opcode,
815 				(u16)rdisp->rinfo->recv_pkt->rh.r.subcode));
816 	}
817 
818 	return total_pkts_processed;
819 }
820 
821 /* Enable Pkt Interrupt */
822 int
823 octeon_enable_irq(struct octeon_device *oct, u32 q_no)
824 {
825 	switch (oct->chip_id) {
826 	case OCTEON_CN66XX:
827 	case OCTEON_CN68XX: {
828 		struct octeon_cn6xxx *cn6xxx =
829 			(struct octeon_cn6xxx *)oct->chip;
830 		unsigned long flags;
831 		u32 value;
832 
833 		spin_lock_irqsave
834 			(&cn6xxx->lock_for_droq_int_enb_reg, flags);
835 		value = octeon_read_csr(oct, CN6XXX_SLI_PKT_TIME_INT_ENB);
836 		value |= (1 << q_no);
837 		octeon_write_csr(oct, CN6XXX_SLI_PKT_TIME_INT_ENB, value);
838 		value = octeon_read_csr(oct, CN6XXX_SLI_PKT_CNT_INT_ENB);
839 		value |= (1 << q_no);
840 		octeon_write_csr(oct, CN6XXX_SLI_PKT_CNT_INT_ENB, value);
841 
842 		/* don't bother flushing the enables */
843 
844 		spin_unlock_irqrestore
845 			(&cn6xxx->lock_for_droq_int_enb_reg, flags);
846 	}
847 		break;
848 	case OCTEON_CN23XX_PF_VID:
849 		lio_enable_irq(oct->droq[q_no], oct->instr_queue[q_no]);
850 		break;
851 
852 	case OCTEON_CN23XX_VF_VID:
853 		lio_enable_irq(oct->droq[q_no], oct->instr_queue[q_no]);
854 		break;
855 	default:
856 		dev_err(&oct->pci_dev->dev, "%s Unknown Chip\n", __func__);
857 		return 1;
858 	}
859 
860 	return 0;
861 }
862 
863 int octeon_register_droq_ops(struct octeon_device *oct, u32 q_no,
864 			     struct octeon_droq_ops *ops)
865 {
866 	struct octeon_config *oct_cfg = NULL;
867 	struct octeon_droq *droq;
868 
869 	oct_cfg = octeon_get_conf(oct);
870 
871 	if (!oct_cfg)
872 		return -EINVAL;
873 
874 	if (!(ops)) {
875 		dev_err(&oct->pci_dev->dev, "%s: droq_ops pointer is NULL\n",
876 			__func__);
877 		return -EINVAL;
878 	}
879 
880 	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
881 		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
882 			__func__, q_no, (oct->num_oqs - 1));
883 		return -EINVAL;
884 	}
885 
886 	droq = oct->droq[q_no];
887 	memcpy(&droq->ops, ops, sizeof(struct octeon_droq_ops));
888 
889 	return 0;
890 }
891 
892 int octeon_unregister_droq_ops(struct octeon_device *oct, u32 q_no)
893 {
894 	struct octeon_config *oct_cfg = NULL;
895 	struct octeon_droq *droq;
896 
897 	oct_cfg = octeon_get_conf(oct);
898 
899 	if (!oct_cfg)
900 		return -EINVAL;
901 
902 	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
903 		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
904 			__func__, q_no, oct->num_oqs - 1);
905 		return -EINVAL;
906 	}
907 
908 	droq = oct->droq[q_no];
909 
910 	if (!droq) {
911 		dev_info(&oct->pci_dev->dev,
912 			 "Droq id (%d) not available.\n", q_no);
913 		return 0;
914 	}
915 
916 	droq->ops.fptr = NULL;
917 	droq->ops.farg = NULL;
918 	droq->ops.drop_on_max = 0;
919 
920 	return 0;
921 }
922 EXPORT_SYMBOL_GPL(octeon_unregister_droq_ops);
923 
924 int octeon_create_droq(struct octeon_device *oct,
925 		       u32 q_no, u32 num_descs,
926 		       u32 desc_size, void *app_ctx)
927 {
928 	struct octeon_droq *droq;
929 	int numa_node = dev_to_node(&oct->pci_dev->dev);
930 
931 	if (oct->droq[q_no]) {
932 		dev_dbg(&oct->pci_dev->dev, "Droq already in use. Cannot create droq %d again\n",
933 			q_no);
934 		return 1;
935 	}
936 
937 	/* Allocate the DS for the new droq. */
938 	droq = vmalloc_node(sizeof(*droq), numa_node);
939 	if (!droq)
940 		droq = vmalloc(sizeof(*droq));
941 	if (!droq)
942 		return -1;
943 
944 	memset(droq, 0, sizeof(struct octeon_droq));
945 
946 	/*Disable the pkt o/p for this Q  */
947 	octeon_set_droq_pkt_op(oct, q_no, 0);
948 	oct->droq[q_no] = droq;
949 
950 	/* Initialize the Droq */
951 	if (octeon_init_droq(oct, q_no, num_descs, desc_size, app_ctx)) {
952 		vfree(oct->droq[q_no]);
953 		oct->droq[q_no] = NULL;
954 		return -1;
955 	}
956 
957 	oct->num_oqs++;
958 
959 	dev_dbg(&oct->pci_dev->dev, "%s: Total number of OQ: %d\n", __func__,
960 		oct->num_oqs);
961 
962 	/* Global Droq register settings */
963 
964 	/* As of now not required, as setting are done for all 32 Droqs at
965 	 * the same time.
966 	 */
967 	return 0;
968 }
969