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 niclist {
34 	struct list_head list;
35 	void *ptr;
36 };
37 
38 struct __dispatch {
39 	struct list_head list;
40 	struct octeon_recv_info *rinfo;
41 	octeon_dispatch_fn_t disp_fn;
42 };
43 
44 /** Get the argument that the user set when registering dispatch
45  *  function for a given opcode/subcode.
46  *  @param  octeon_dev - the octeon device pointer.
47  *  @param  opcode     - the opcode for which the dispatch argument
48  *                       is to be checked.
49  *  @param  subcode    - the subcode for which the dispatch argument
50  *                       is to be checked.
51  *  @return  Success: void * (argument to the dispatch function)
52  *  @return  Failure: NULL
53  *
54  */
55 void *octeon_get_dispatch_arg(struct octeon_device *octeon_dev,
56 			      u16 opcode, u16 subcode)
57 {
58 	int idx;
59 	struct list_head *dispatch;
60 	void *fn_arg = NULL;
61 	u16 combined_opcode = OPCODE_SUBCODE(opcode, subcode);
62 
63 	idx = combined_opcode & OCTEON_OPCODE_MASK;
64 
65 	spin_lock_bh(&octeon_dev->dispatch.lock);
66 
67 	if (octeon_dev->dispatch.count == 0) {
68 		spin_unlock_bh(&octeon_dev->dispatch.lock);
69 		return NULL;
70 	}
71 
72 	if (octeon_dev->dispatch.dlist[idx].opcode == combined_opcode) {
73 		fn_arg = octeon_dev->dispatch.dlist[idx].arg;
74 	} else {
75 		list_for_each(dispatch,
76 			      &octeon_dev->dispatch.dlist[idx].list) {
77 			if (((struct octeon_dispatch *)dispatch)->opcode ==
78 			    combined_opcode) {
79 				fn_arg = ((struct octeon_dispatch *)
80 					  dispatch)->arg;
81 				break;
82 			}
83 		}
84 	}
85 
86 	spin_unlock_bh(&octeon_dev->dispatch.lock);
87 	return fn_arg;
88 }
89 
90 /** Check for packets on Droq. This function should be called with lock held.
91  *  @param  droq - Droq on which count is checked.
92  *  @return Returns packet count.
93  */
94 u32 octeon_droq_check_hw_for_pkts(struct octeon_droq *droq)
95 {
96 	u32 pkt_count = 0;
97 	u32 last_count;
98 
99 	pkt_count = readl(droq->pkts_sent_reg);
100 
101 	last_count = pkt_count - droq->pkt_count;
102 	droq->pkt_count = pkt_count;
103 
104 	/* we shall write to cnts  at napi irq enable or end of droq tasklet */
105 	if (last_count)
106 		atomic_add(last_count, &droq->pkts_pending);
107 
108 	return last_count;
109 }
110 
111 static void octeon_droq_compute_max_packet_bufs(struct octeon_droq *droq)
112 {
113 	u32 count = 0;
114 
115 	/* max_empty_descs is the max. no. of descs that can have no buffers.
116 	 * If the empty desc count goes beyond this value, we cannot safely
117 	 * read in a 64K packet sent by Octeon
118 	 * (64K is max pkt size from Octeon)
119 	 */
120 	droq->max_empty_descs = 0;
121 
122 	do {
123 		droq->max_empty_descs++;
124 		count += droq->buffer_size;
125 	} while (count < (64 * 1024));
126 
127 	droq->max_empty_descs = droq->max_count - droq->max_empty_descs;
128 }
129 
130 static void octeon_droq_reset_indices(struct octeon_droq *droq)
131 {
132 	droq->read_idx = 0;
133 	droq->write_idx = 0;
134 	droq->refill_idx = 0;
135 	droq->refill_count = 0;
136 	atomic_set(&droq->pkts_pending, 0);
137 }
138 
139 static void
140 octeon_droq_destroy_ring_buffers(struct octeon_device *oct,
141 				 struct octeon_droq *droq)
142 {
143 	u32 i;
144 	struct octeon_skb_page_info *pg_info;
145 
146 	for (i = 0; i < droq->max_count; i++) {
147 		pg_info = &droq->recv_buf_list[i].pg_info;
148 		if (!pg_info)
149 			continue;
150 
151 		if (pg_info->dma)
152 			lio_unmap_ring(oct->pci_dev,
153 				       (u64)pg_info->dma);
154 		pg_info->dma = 0;
155 
156 		if (pg_info->page)
157 			recv_buffer_destroy(droq->recv_buf_list[i].buffer,
158 					    pg_info);
159 
160 		droq->recv_buf_list[i].buffer = NULL;
161 	}
162 
163 	octeon_droq_reset_indices(droq);
164 }
165 
166 static int
167 octeon_droq_setup_ring_buffers(struct octeon_device *oct,
168 			       struct octeon_droq *droq)
169 {
170 	u32 i;
171 	void *buf;
172 	struct octeon_droq_desc *desc_ring = droq->desc_ring;
173 
174 	for (i = 0; i < droq->max_count; i++) {
175 		buf = recv_buffer_alloc(oct, &droq->recv_buf_list[i].pg_info);
176 
177 		if (!buf) {
178 			dev_err(&oct->pci_dev->dev, "%s buffer alloc failed\n",
179 				__func__);
180 			droq->stats.rx_alloc_failure++;
181 			return -ENOMEM;
182 		}
183 
184 		droq->recv_buf_list[i].buffer = buf;
185 		droq->recv_buf_list[i].data = get_rbd(buf);
186 		desc_ring[i].info_ptr = 0;
187 		desc_ring[i].buffer_ptr =
188 			lio_map_ring(droq->recv_buf_list[i].buffer);
189 	}
190 
191 	octeon_droq_reset_indices(droq);
192 
193 	octeon_droq_compute_max_packet_bufs(droq);
194 
195 	return 0;
196 }
197 
198 int octeon_delete_droq(struct octeon_device *oct, u32 q_no)
199 {
200 	struct octeon_droq *droq = oct->droq[q_no];
201 
202 	dev_dbg(&oct->pci_dev->dev, "%s[%d]\n", __func__, q_no);
203 
204 	octeon_droq_destroy_ring_buffers(oct, droq);
205 	vfree(droq->recv_buf_list);
206 
207 	if (droq->desc_ring)
208 		lio_dma_free(oct, (droq->max_count * OCT_DROQ_DESC_SIZE),
209 			     droq->desc_ring, droq->desc_ring_dma);
210 
211 	memset(droq, 0, OCT_DROQ_SIZE);
212 	oct->io_qmask.oq &= ~(1ULL << q_no);
213 	vfree(oct->droq[q_no]);
214 	oct->droq[q_no] = NULL;
215 	oct->num_oqs--;
216 
217 	return 0;
218 }
219 
220 int octeon_init_droq(struct octeon_device *oct,
221 		     u32 q_no,
222 		     u32 num_descs,
223 		     u32 desc_size,
224 		     void *app_ctx)
225 {
226 	struct octeon_droq *droq;
227 	u32 desc_ring_size = 0, c_num_descs = 0, c_buf_size = 0;
228 	u32 c_pkts_per_intr = 0, c_refill_threshold = 0;
229 	int numa_node = dev_to_node(&oct->pci_dev->dev);
230 
231 	dev_dbg(&oct->pci_dev->dev, "%s[%d]\n", __func__, q_no);
232 
233 	droq = oct->droq[q_no];
234 	memset(droq, 0, OCT_DROQ_SIZE);
235 
236 	droq->oct_dev = oct;
237 	droq->q_no = q_no;
238 	if (app_ctx)
239 		droq->app_ctx = app_ctx;
240 	else
241 		droq->app_ctx = (void *)(size_t)q_no;
242 
243 	c_num_descs = num_descs;
244 	c_buf_size = desc_size;
245 	if (OCTEON_CN6XXX(oct)) {
246 		struct octeon_config *conf6x = CHIP_CONF(oct, cn6xxx);
247 
248 		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf6x);
249 		c_refill_threshold =
250 			(u32)CFG_GET_OQ_REFILL_THRESHOLD(conf6x);
251 	} else if (OCTEON_CN23XX_PF(oct)) {
252 		struct octeon_config *conf23 = CHIP_CONF(oct, cn23xx_pf);
253 
254 		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf23);
255 		c_refill_threshold = (u32)CFG_GET_OQ_REFILL_THRESHOLD(conf23);
256 	} else if (OCTEON_CN23XX_VF(oct)) {
257 		struct octeon_config *conf23 = CHIP_CONF(oct, cn23xx_vf);
258 
259 		c_pkts_per_intr = (u32)CFG_GET_OQ_PKTS_PER_INTR(conf23);
260 		c_refill_threshold = (u32)CFG_GET_OQ_REFILL_THRESHOLD(conf23);
261 	} else {
262 		return 1;
263 	}
264 
265 	droq->max_count = c_num_descs;
266 	droq->buffer_size = c_buf_size;
267 
268 	desc_ring_size = droq->max_count * OCT_DROQ_DESC_SIZE;
269 	droq->desc_ring = lio_dma_alloc(oct, desc_ring_size,
270 					(dma_addr_t *)&droq->desc_ring_dma);
271 
272 	if (!droq->desc_ring) {
273 		dev_err(&oct->pci_dev->dev,
274 			"Output queue %d ring alloc failed\n", q_no);
275 		return 1;
276 	}
277 
278 	dev_dbg(&oct->pci_dev->dev, "droq[%d]: desc_ring: virt: 0x%p, dma: %lx\n",
279 		q_no, droq->desc_ring, droq->desc_ring_dma);
280 	dev_dbg(&oct->pci_dev->dev, "droq[%d]: num_desc: %d\n", q_no,
281 		droq->max_count);
282 
283 	droq->recv_buf_list = (struct octeon_recv_buffer *)
284 			      vzalloc_node(droq->max_count *
285 						OCT_DROQ_RECVBUF_SIZE,
286 						numa_node);
287 	if (!droq->recv_buf_list)
288 		droq->recv_buf_list = (struct octeon_recv_buffer *)
289 				      vzalloc(droq->max_count *
290 						OCT_DROQ_RECVBUF_SIZE);
291 	if (!droq->recv_buf_list) {
292 		dev_err(&oct->pci_dev->dev, "Output queue recv buf list alloc failed\n");
293 		goto init_droq_fail;
294 	}
295 
296 	if (octeon_droq_setup_ring_buffers(oct, droq))
297 		goto init_droq_fail;
298 
299 	droq->pkts_per_intr = c_pkts_per_intr;
300 	droq->refill_threshold = c_refill_threshold;
301 
302 	dev_dbg(&oct->pci_dev->dev, "DROQ INIT: max_empty_descs: %d\n",
303 		droq->max_empty_descs);
304 
305 	spin_lock_init(&droq->lock);
306 
307 	INIT_LIST_HEAD(&droq->dispatch_list);
308 
309 	/* For 56xx Pass1, this function won't be called, so no checks. */
310 	oct->fn_list.setup_oq_regs(oct, q_no);
311 
312 	oct->io_qmask.oq |= BIT_ULL(q_no);
313 
314 	return 0;
315 
316 init_droq_fail:
317 	octeon_delete_droq(oct, q_no);
318 	return 1;
319 }
320 
321 /* octeon_create_recv_info
322  * Parameters:
323  *  octeon_dev - pointer to the octeon device structure
324  *  droq       - droq in which the packet arrived.
325  *  buf_cnt    - no. of buffers used by the packet.
326  *  idx        - index in the descriptor for the first buffer in the packet.
327  * Description:
328  *  Allocates a recv_info_t and copies the buffer addresses for packet data
329  *  into the recv_pkt space which starts at an 8B offset from recv_info_t.
330  *  Flags the descriptors for refill later. If available descriptors go
331  *  below the threshold to receive a 64K pkt, new buffers are first allocated
332  *  before the recv_pkt_t is created.
333  *  This routine will be called in interrupt context.
334  * Returns:
335  *  Success: Pointer to recv_info_t
336  *  Failure: NULL.
337  * Locks:
338  *  The droq->lock is held when this routine is called.
339  */
340 static inline struct octeon_recv_info *octeon_create_recv_info(
341 		struct octeon_device *octeon_dev,
342 		struct octeon_droq *droq,
343 		u32 buf_cnt,
344 		u32 idx)
345 {
346 	struct octeon_droq_info *info;
347 	struct octeon_recv_pkt *recv_pkt;
348 	struct octeon_recv_info *recv_info;
349 	u32 i, bytes_left;
350 	struct octeon_skb_page_info *pg_info;
351 
352 	info = (struct octeon_droq_info *)droq->recv_buf_list[idx].data;
353 
354 	recv_info = octeon_alloc_recv_info(sizeof(struct __dispatch));
355 	if (!recv_info)
356 		return NULL;
357 
358 	recv_pkt = recv_info->recv_pkt;
359 	recv_pkt->rh = info->rh;
360 	recv_pkt->length = (u32)info->length;
361 	recv_pkt->buffer_count = (u16)buf_cnt;
362 	recv_pkt->octeon_id = (u16)octeon_dev->octeon_id;
363 
364 	i = 0;
365 	bytes_left = (u32)info->length;
366 
367 	while (buf_cnt) {
368 		{
369 			pg_info = &droq->recv_buf_list[idx].pg_info;
370 
371 			lio_unmap_ring(octeon_dev->pci_dev,
372 				       (u64)pg_info->dma);
373 			pg_info->page = NULL;
374 			pg_info->dma = 0;
375 		}
376 
377 		recv_pkt->buffer_size[i] =
378 			(bytes_left >=
379 			 droq->buffer_size) ? droq->buffer_size : bytes_left;
380 
381 		recv_pkt->buffer_ptr[i] = droq->recv_buf_list[idx].buffer;
382 		droq->recv_buf_list[idx].buffer = NULL;
383 
384 		idx = incr_index(idx, 1, droq->max_count);
385 		bytes_left -= droq->buffer_size;
386 		i++;
387 		buf_cnt--;
388 	}
389 
390 	return recv_info;
391 }
392 
393 /* If we were not able to refill all buffers, try to move around
394  * the buffers that were not dispatched.
395  */
396 static inline u32
397 octeon_droq_refill_pullup_descs(struct octeon_droq *droq,
398 				struct octeon_droq_desc *desc_ring)
399 {
400 	u32 desc_refilled = 0;
401 
402 	u32 refill_index = droq->refill_idx;
403 
404 	while (refill_index != droq->read_idx) {
405 		if (droq->recv_buf_list[refill_index].buffer) {
406 			droq->recv_buf_list[droq->refill_idx].buffer =
407 				droq->recv_buf_list[refill_index].buffer;
408 			droq->recv_buf_list[droq->refill_idx].data =
409 				droq->recv_buf_list[refill_index].data;
410 			desc_ring[droq->refill_idx].buffer_ptr =
411 				desc_ring[refill_index].buffer_ptr;
412 			droq->recv_buf_list[refill_index].buffer = NULL;
413 			desc_ring[refill_index].buffer_ptr = 0;
414 			do {
415 				droq->refill_idx = incr_index(droq->refill_idx,
416 							      1,
417 							      droq->max_count);
418 				desc_refilled++;
419 				droq->refill_count--;
420 			} while (droq->recv_buf_list[droq->refill_idx].buffer);
421 		}
422 		refill_index = incr_index(refill_index, 1, droq->max_count);
423 	}                       /* while */
424 	return desc_refilled;
425 }
426 
427 /* octeon_droq_refill
428  * Parameters:
429  *  droq       - droq in which descriptors require new buffers.
430  * Description:
431  *  Called during normal DROQ processing in interrupt mode or by the poll
432  *  thread to refill the descriptors from which buffers were dispatched
433  *  to upper layers. Attempts to allocate new buffers. If that fails, moves
434  *  up buffers (that were not dispatched) to form a contiguous ring.
435  * Returns:
436  *  No of descriptors refilled.
437  * Locks:
438  *  This routine is called with droq->lock held.
439  */
440 static u32
441 octeon_droq_refill(struct octeon_device *octeon_dev, struct octeon_droq *droq)
442 {
443 	struct octeon_droq_desc *desc_ring;
444 	void *buf = NULL;
445 	u8 *data;
446 	u32 desc_refilled = 0;
447 	struct octeon_skb_page_info *pg_info;
448 
449 	desc_ring = droq->desc_ring;
450 
451 	while (droq->refill_count && (desc_refilled < droq->max_count)) {
452 		/* If a valid buffer exists (happens if there is no dispatch),
453 		 * reuse
454 		 * the buffer, else allocate.
455 		 */
456 		if (!droq->recv_buf_list[droq->refill_idx].buffer) {
457 			pg_info =
458 				&droq->recv_buf_list[droq->refill_idx].pg_info;
459 			/* Either recycle the existing pages or go for
460 			 * new page alloc
461 			 */
462 			if (pg_info->page)
463 				buf = recv_buffer_reuse(octeon_dev, pg_info);
464 			else
465 				buf = recv_buffer_alloc(octeon_dev, pg_info);
466 			/* If a buffer could not be allocated, no point in
467 			 * continuing
468 			 */
469 			if (!buf) {
470 				droq->stats.rx_alloc_failure++;
471 				break;
472 			}
473 			droq->recv_buf_list[droq->refill_idx].buffer =
474 				buf;
475 			data = get_rbd(buf);
476 		} else {
477 			data = get_rbd(droq->recv_buf_list
478 				       [droq->refill_idx].buffer);
479 		}
480 
481 		droq->recv_buf_list[droq->refill_idx].data = data;
482 
483 		desc_ring[droq->refill_idx].buffer_ptr =
484 			lio_map_ring(droq->recv_buf_list[
485 				     droq->refill_idx].buffer);
486 
487 		droq->refill_idx = incr_index(droq->refill_idx, 1,
488 					      droq->max_count);
489 		desc_refilled++;
490 		droq->refill_count--;
491 	}
492 
493 	if (droq->refill_count)
494 		desc_refilled +=
495 			octeon_droq_refill_pullup_descs(droq, desc_ring);
496 
497 	/* if droq->refill_count
498 	 * The refill count would not change in pass two. We only moved buffers
499 	 * to close the gap in the ring, but we would still have the same no. of
500 	 * buffers to refill.
501 	 */
502 	return desc_refilled;
503 }
504 
505 /** check if we can allocate packets to get out of oom.
506  *  @param  droq - Droq being checked.
507  *  @return does not return anything
508  */
509 void octeon_droq_check_oom(struct octeon_droq *droq)
510 {
511 	int desc_refilled;
512 	struct octeon_device *oct = droq->oct_dev;
513 
514 	if (readl(droq->pkts_credit_reg) <= CN23XX_SLI_DEF_BP) {
515 		spin_lock_bh(&droq->lock);
516 		desc_refilled = octeon_droq_refill(oct, droq);
517 		if (desc_refilled) {
518 			/* Flush the droq descriptor data to memory to be sure
519 			 * that when we update the credits the data in memory
520 			 * is accurate.
521 			 */
522 			wmb();
523 			writel(desc_refilled, droq->pkts_credit_reg);
524 			/* make sure mmio write completes */
525 			mmiowb();
526 		}
527 		spin_unlock_bh(&droq->lock);
528 	}
529 }
530 
531 static inline u32
532 octeon_droq_get_bufcount(u32 buf_size, u32 total_len)
533 {
534 	return ((total_len + buf_size - 1) / buf_size);
535 }
536 
537 static int
538 octeon_droq_dispatch_pkt(struct octeon_device *oct,
539 			 struct octeon_droq *droq,
540 			 union octeon_rh *rh,
541 			 struct octeon_droq_info *info)
542 {
543 	u32 cnt;
544 	octeon_dispatch_fn_t disp_fn;
545 	struct octeon_recv_info *rinfo;
546 
547 	cnt = octeon_droq_get_bufcount(droq->buffer_size, (u32)info->length);
548 
549 	disp_fn = octeon_get_dispatch(oct, (u16)rh->r.opcode,
550 				      (u16)rh->r.subcode);
551 	if (disp_fn) {
552 		rinfo = octeon_create_recv_info(oct, droq, cnt, droq->read_idx);
553 		if (rinfo) {
554 			struct __dispatch *rdisp = rinfo->rsvd;
555 
556 			rdisp->rinfo = rinfo;
557 			rdisp->disp_fn = disp_fn;
558 			rinfo->recv_pkt->rh = *rh;
559 			list_add_tail(&rdisp->list,
560 				      &droq->dispatch_list);
561 		} else {
562 			droq->stats.dropped_nomem++;
563 		}
564 	} else {
565 		dev_err(&oct->pci_dev->dev, "DROQ: No dispatch function (opcode %u/%u)\n",
566 			(unsigned int)rh->r.opcode,
567 			(unsigned int)rh->r.subcode);
568 		droq->stats.dropped_nodispatch++;
569 	}
570 
571 	return cnt;
572 }
573 
574 static inline void octeon_droq_drop_packets(struct octeon_device *oct,
575 					    struct octeon_droq *droq,
576 					    u32 cnt)
577 {
578 	u32 i = 0, buf_cnt;
579 	struct octeon_droq_info *info;
580 
581 	for (i = 0; i < cnt; i++) {
582 		info = (struct octeon_droq_info *)
583 			droq->recv_buf_list[droq->read_idx].data;
584 		octeon_swap_8B_data((u64 *)info, 2);
585 
586 		if (info->length) {
587 			info->length += OCTNET_FRM_LENGTH_SIZE;
588 			droq->stats.bytes_received += info->length;
589 			buf_cnt = octeon_droq_get_bufcount(droq->buffer_size,
590 							   (u32)info->length);
591 		} else {
592 			dev_err(&oct->pci_dev->dev, "DROQ: In drop: pkt with len 0\n");
593 			buf_cnt = 1;
594 		}
595 
596 		droq->read_idx = incr_index(droq->read_idx, buf_cnt,
597 					    droq->max_count);
598 		droq->refill_count += buf_cnt;
599 	}
600 }
601 
602 static u32
603 octeon_droq_fast_process_packets(struct octeon_device *oct,
604 				 struct octeon_droq *droq,
605 				 u32 pkts_to_process)
606 {
607 	struct octeon_droq_info *info;
608 	union octeon_rh *rh;
609 	u32 pkt, total_len = 0, pkt_count;
610 
611 	pkt_count = pkts_to_process;
612 
613 	for (pkt = 0; pkt < pkt_count; pkt++) {
614 		u32 pkt_len = 0;
615 		struct sk_buff *nicbuf = NULL;
616 		struct octeon_skb_page_info *pg_info;
617 		void *buf;
618 
619 		info = (struct octeon_droq_info *)
620 			droq->recv_buf_list[droq->read_idx].data;
621 		octeon_swap_8B_data((u64 *)info, 2);
622 
623 		if (!info->length) {
624 			dev_err(&oct->pci_dev->dev,
625 				"DROQ[%d] idx: %d len:0, pkt_cnt: %d\n",
626 				droq->q_no, droq->read_idx, pkt_count);
627 			print_hex_dump_bytes("", DUMP_PREFIX_ADDRESS,
628 					     (u8 *)info,
629 					     OCT_DROQ_INFO_SIZE);
630 			break;
631 		}
632 
633 		/* Len of resp hdr in included in the received data len. */
634 		rh = &info->rh;
635 
636 		info->length += OCTNET_FRM_LENGTH_SIZE;
637 		rh->r_dh.len += (ROUNDUP8(OCT_DROQ_INFO_SIZE) / sizeof(u64));
638 		total_len += (u32)info->length;
639 		if (opcode_slow_path(rh)) {
640 			u32 buf_cnt;
641 
642 			buf_cnt = octeon_droq_dispatch_pkt(oct, droq, rh, info);
643 			droq->read_idx = incr_index(droq->read_idx,
644 						    buf_cnt, droq->max_count);
645 			droq->refill_count += buf_cnt;
646 		} else {
647 			if (info->length <= droq->buffer_size) {
648 				pkt_len = (u32)info->length;
649 				nicbuf = droq->recv_buf_list[
650 					droq->read_idx].buffer;
651 				pg_info = &droq->recv_buf_list[
652 					droq->read_idx].pg_info;
653 				if (recv_buffer_recycle(oct, pg_info))
654 					pg_info->page = NULL;
655 				droq->recv_buf_list[droq->read_idx].buffer =
656 					NULL;
657 
658 				droq->read_idx = incr_index(droq->read_idx, 1,
659 							    droq->max_count);
660 				droq->refill_count++;
661 			} else {
662 				nicbuf = octeon_fast_packet_alloc((u32)
663 								  info->length);
664 				pkt_len = 0;
665 				/* nicbuf allocation can fail. We'll handle it
666 				 * inside the loop.
667 				 */
668 				while (pkt_len < info->length) {
669 					int cpy_len, idx = droq->read_idx;
670 
671 					cpy_len = ((pkt_len + droq->buffer_size)
672 						   > info->length) ?
673 						((u32)info->length - pkt_len) :
674 						droq->buffer_size;
675 
676 					if (nicbuf) {
677 						octeon_fast_packet_next(droq,
678 									nicbuf,
679 									cpy_len,
680 									idx);
681 						buf = droq->recv_buf_list[
682 							idx].buffer;
683 						recv_buffer_fast_free(buf);
684 						droq->recv_buf_list[idx].buffer
685 							= NULL;
686 					} else {
687 						droq->stats.rx_alloc_failure++;
688 					}
689 
690 					pkt_len += cpy_len;
691 					droq->read_idx =
692 						incr_index(droq->read_idx, 1,
693 							   droq->max_count);
694 					droq->refill_count++;
695 				}
696 			}
697 
698 			if (nicbuf) {
699 				if (droq->ops.fptr) {
700 					droq->ops.fptr(oct->octeon_id,
701 						       nicbuf, pkt_len,
702 						       rh, &droq->napi,
703 						       droq->ops.farg);
704 				} else {
705 					recv_buffer_free(nicbuf);
706 				}
707 			}
708 		}
709 
710 		if (droq->refill_count >= droq->refill_threshold) {
711 			int desc_refilled = octeon_droq_refill(oct, droq);
712 
713 			/* Flush the droq descriptor data to memory to be sure
714 			 * that when we update the credits the data in memory
715 			 * is accurate.
716 			 */
717 			wmb();
718 			writel((desc_refilled), droq->pkts_credit_reg);
719 			/* make sure mmio write completes */
720 			mmiowb();
721 		}
722 
723 	}                       /* for (each packet)... */
724 
725 	/* Increment refill_count by the number of buffers processed. */
726 	droq->stats.pkts_received += pkt;
727 	droq->stats.bytes_received += total_len;
728 
729 	if ((droq->ops.drop_on_max) && (pkts_to_process - pkt)) {
730 		octeon_droq_drop_packets(oct, droq, (pkts_to_process - pkt));
731 
732 		droq->stats.dropped_toomany += (pkts_to_process - pkt);
733 		return pkts_to_process;
734 	}
735 
736 	return pkt;
737 }
738 
739 int
740 octeon_droq_process_packets(struct octeon_device *oct,
741 			    struct octeon_droq *droq,
742 			    u32 budget)
743 {
744 	u32 pkt_count = 0, pkts_processed = 0;
745 	struct list_head *tmp, *tmp2;
746 
747 	/* Grab the droq lock */
748 	spin_lock(&droq->lock);
749 
750 	octeon_droq_check_hw_for_pkts(droq);
751 	pkt_count = atomic_read(&droq->pkts_pending);
752 
753 	if (!pkt_count) {
754 		spin_unlock(&droq->lock);
755 		return 0;
756 	}
757 
758 	if (pkt_count > budget)
759 		pkt_count = budget;
760 
761 	pkts_processed = octeon_droq_fast_process_packets(oct, droq, pkt_count);
762 
763 	atomic_sub(pkts_processed, &droq->pkts_pending);
764 
765 	/* Release the spin lock */
766 	spin_unlock(&droq->lock);
767 
768 	list_for_each_safe(tmp, tmp2, &droq->dispatch_list) {
769 		struct __dispatch *rdisp = (struct __dispatch *)tmp;
770 
771 		list_del(tmp);
772 		rdisp->disp_fn(rdisp->rinfo,
773 			       octeon_get_dispatch_arg
774 			       (oct,
775 				(u16)rdisp->rinfo->recv_pkt->rh.r.opcode,
776 				(u16)rdisp->rinfo->recv_pkt->rh.r.subcode));
777 	}
778 
779 	/* If there are packets pending. schedule tasklet again */
780 	if (atomic_read(&droq->pkts_pending))
781 		return 1;
782 
783 	return 0;
784 }
785 
786 /**
787  * Utility function to poll for packets. check_hw_for_packets must be
788  * called before calling this routine.
789  */
790 
791 static int
792 octeon_droq_process_poll_pkts(struct octeon_device *oct,
793 			      struct octeon_droq *droq, u32 budget)
794 {
795 	struct list_head *tmp, *tmp2;
796 	u32 pkts_available = 0, pkts_processed = 0;
797 	u32 total_pkts_processed = 0;
798 
799 	if (budget > droq->max_count)
800 		budget = droq->max_count;
801 
802 	spin_lock(&droq->lock);
803 
804 	while (total_pkts_processed < budget) {
805 		octeon_droq_check_hw_for_pkts(droq);
806 
807 		pkts_available = min((budget - total_pkts_processed),
808 				     (u32)(atomic_read(&droq->pkts_pending)));
809 
810 		if (pkts_available == 0)
811 			break;
812 
813 		pkts_processed =
814 			octeon_droq_fast_process_packets(oct, droq,
815 							 pkts_available);
816 
817 		atomic_sub(pkts_processed, &droq->pkts_pending);
818 
819 		total_pkts_processed += pkts_processed;
820 	}
821 
822 	spin_unlock(&droq->lock);
823 
824 	list_for_each_safe(tmp, tmp2, &droq->dispatch_list) {
825 		struct __dispatch *rdisp = (struct __dispatch *)tmp;
826 
827 		list_del(tmp);
828 		rdisp->disp_fn(rdisp->rinfo,
829 			       octeon_get_dispatch_arg
830 			       (oct,
831 				(u16)rdisp->rinfo->recv_pkt->rh.r.opcode,
832 				(u16)rdisp->rinfo->recv_pkt->rh.r.subcode));
833 	}
834 
835 	return total_pkts_processed;
836 }
837 
838 int
839 octeon_process_droq_poll_cmd(struct octeon_device *oct, u32 q_no, int cmd,
840 			     u32 arg)
841 {
842 	struct octeon_droq *droq;
843 
844 	droq = oct->droq[q_no];
845 
846 	if (cmd == POLL_EVENT_PROCESS_PKTS)
847 		return octeon_droq_process_poll_pkts(oct, droq, arg);
848 
849 	if (cmd == POLL_EVENT_PENDING_PKTS) {
850 		u32 pkt_cnt = atomic_read(&droq->pkts_pending);
851 
852 		return  octeon_droq_process_packets(oct, droq, pkt_cnt);
853 	}
854 
855 	if (cmd == POLL_EVENT_ENABLE_INTR) {
856 		u32 value;
857 		unsigned long flags;
858 
859 		/* Enable Pkt Interrupt */
860 		switch (oct->chip_id) {
861 		case OCTEON_CN66XX:
862 		case OCTEON_CN68XX: {
863 			struct octeon_cn6xxx *cn6xxx =
864 				(struct octeon_cn6xxx *)oct->chip;
865 			spin_lock_irqsave
866 				(&cn6xxx->lock_for_droq_int_enb_reg, flags);
867 			value =
868 				octeon_read_csr(oct,
869 						CN6XXX_SLI_PKT_TIME_INT_ENB);
870 			value |= (1 << q_no);
871 			octeon_write_csr(oct,
872 					 CN6XXX_SLI_PKT_TIME_INT_ENB,
873 					 value);
874 			value =
875 				octeon_read_csr(oct,
876 						CN6XXX_SLI_PKT_CNT_INT_ENB);
877 			value |= (1 << q_no);
878 			octeon_write_csr(oct,
879 					 CN6XXX_SLI_PKT_CNT_INT_ENB,
880 					 value);
881 
882 			/* don't bother flushing the enables */
883 
884 			spin_unlock_irqrestore
885 				(&cn6xxx->lock_for_droq_int_enb_reg, flags);
886 			return 0;
887 		}
888 		break;
889 		case OCTEON_CN23XX_PF_VID: {
890 			lio_enable_irq(oct->droq[q_no], oct->instr_queue[q_no]);
891 		}
892 		break;
893 
894 		case OCTEON_CN23XX_VF_VID:
895 			lio_enable_irq(oct->droq[q_no], oct->instr_queue[q_no]);
896 		break;
897 		}
898 		return 0;
899 	}
900 
901 	dev_err(&oct->pci_dev->dev, "%s Unknown command: %d\n", __func__, cmd);
902 	return -EINVAL;
903 }
904 
905 int octeon_register_droq_ops(struct octeon_device *oct, u32 q_no,
906 			     struct octeon_droq_ops *ops)
907 {
908 	struct octeon_droq *droq;
909 	unsigned long flags;
910 	struct octeon_config *oct_cfg = NULL;
911 
912 	oct_cfg = octeon_get_conf(oct);
913 
914 	if (!oct_cfg)
915 		return -EINVAL;
916 
917 	if (!(ops)) {
918 		dev_err(&oct->pci_dev->dev, "%s: droq_ops pointer is NULL\n",
919 			__func__);
920 		return -EINVAL;
921 	}
922 
923 	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
924 		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
925 			__func__, q_no, (oct->num_oqs - 1));
926 		return -EINVAL;
927 	}
928 
929 	droq = oct->droq[q_no];
930 
931 	spin_lock_irqsave(&droq->lock, flags);
932 
933 	memcpy(&droq->ops, ops, sizeof(struct octeon_droq_ops));
934 
935 	spin_unlock_irqrestore(&droq->lock, flags);
936 
937 	return 0;
938 }
939 
940 int octeon_unregister_droq_ops(struct octeon_device *oct, u32 q_no)
941 {
942 	unsigned long flags;
943 	struct octeon_droq *droq;
944 	struct octeon_config *oct_cfg = NULL;
945 
946 	oct_cfg = octeon_get_conf(oct);
947 
948 	if (!oct_cfg)
949 		return -EINVAL;
950 
951 	if (q_no >= CFG_GET_OQ_MAX_Q(oct_cfg)) {
952 		dev_err(&oct->pci_dev->dev, "%s: droq id (%d) exceeds MAX (%d)\n",
953 			__func__, q_no, oct->num_oqs - 1);
954 		return -EINVAL;
955 	}
956 
957 	droq = oct->droq[q_no];
958 
959 	if (!droq) {
960 		dev_info(&oct->pci_dev->dev,
961 			 "Droq id (%d) not available.\n", q_no);
962 		return 0;
963 	}
964 
965 	spin_lock_irqsave(&droq->lock, flags);
966 
967 	droq->ops.fptr = NULL;
968 	droq->ops.farg = NULL;
969 	droq->ops.drop_on_max = 0;
970 
971 	spin_unlock_irqrestore(&droq->lock, flags);
972 
973 	return 0;
974 }
975 
976 int octeon_create_droq(struct octeon_device *oct,
977 		       u32 q_no, u32 num_descs,
978 		       u32 desc_size, void *app_ctx)
979 {
980 	struct octeon_droq *droq;
981 	int numa_node = dev_to_node(&oct->pci_dev->dev);
982 
983 	if (oct->droq[q_no]) {
984 		dev_dbg(&oct->pci_dev->dev, "Droq already in use. Cannot create droq %d again\n",
985 			q_no);
986 		return 1;
987 	}
988 
989 	/* Allocate the DS for the new droq. */
990 	droq = vmalloc_node(sizeof(*droq), numa_node);
991 	if (!droq)
992 		droq = vmalloc(sizeof(*droq));
993 	if (!droq)
994 		return -1;
995 
996 	memset(droq, 0, sizeof(struct octeon_droq));
997 
998 	/*Disable the pkt o/p for this Q  */
999 	octeon_set_droq_pkt_op(oct, q_no, 0);
1000 	oct->droq[q_no] = droq;
1001 
1002 	/* Initialize the Droq */
1003 	if (octeon_init_droq(oct, q_no, num_descs, desc_size, app_ctx)) {
1004 		vfree(oct->droq[q_no]);
1005 		oct->droq[q_no] = NULL;
1006 		return -1;
1007 	}
1008 
1009 	oct->num_oqs++;
1010 
1011 	dev_dbg(&oct->pci_dev->dev, "%s: Total number of OQ: %d\n", __func__,
1012 		oct->num_oqs);
1013 
1014 	/* Global Droq register settings */
1015 
1016 	/* As of now not required, as setting are done for all 32 Droqs at
1017 	 * the same time.
1018 	 */
1019 	return 0;
1020 }
1021