summaryrefslogtreecommitdiff
path: root/drivers/soc/fsl/dpio/dpio-service.c
blob: 518a8e081b490e96aeb2c32b185cbe81e8d72327 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * Copyright 2014-2016 Freescale Semiconductor Inc.
 * Copyright 2016 NXP
 *
 */
#include <linux/types.h>
#include <linux/fsl/mc.h>
#include <soc/fsl/dpaa2-io.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>

#include "dpio.h"
#include "qbman-portal.h"

struct dpaa2_io {
	struct dpaa2_io_desc dpio_desc;
	struct qbman_swp_desc swp_desc;
	struct qbman_swp *swp;
	struct list_head node;
	/* protect against multiple management commands */
	spinlock_t lock_mgmt_cmd;
	/* protect notifications list */
	spinlock_t lock_notifications;
	struct list_head notifications;
	struct device *dev;
};

struct dpaa2_io_store {
	unsigned int max;
	dma_addr_t paddr;
	struct dpaa2_dq *vaddr;
	void *alloced_addr;    /* unaligned value from kmalloc() */
	unsigned int idx;      /* position of the next-to-be-returned entry */
	struct qbman_swp *swp; /* portal used to issue VDQCR */
	struct device *dev;    /* device used for DMA mapping */
};

/* keep a per cpu array of DPIOs for fast access */
static struct dpaa2_io *dpio_by_cpu[NR_CPUS];
static struct list_head dpio_list = LIST_HEAD_INIT(dpio_list);
static DEFINE_SPINLOCK(dpio_list_lock);

static inline struct dpaa2_io *service_select_by_cpu(struct dpaa2_io *d,
						     int cpu)
{
	if (d)
		return d;

	if (cpu != DPAA2_IO_ANY_CPU && cpu >= num_possible_cpus())
		return NULL;

	/*
	 * If cpu == -1, choose the current cpu, with no guarantees about
	 * potentially being migrated away.
	 */
	if (unlikely(cpu < 0))
		cpu = smp_processor_id();

	/* If a specific cpu was requested, pick it up immediately */
	return dpio_by_cpu[cpu];
}

static inline struct dpaa2_io *service_select(struct dpaa2_io *d)
{
	if (d)
		return d;

	spin_lock(&dpio_list_lock);
	d = list_entry(dpio_list.next, struct dpaa2_io, node);
	list_del(&d->node);
	list_add_tail(&d->node, &dpio_list);
	spin_unlock(&dpio_list_lock);

	return d;
}

/**
 * dpaa2_io_service_select() - return a dpaa2_io service affined to this cpu
 * @cpu: the cpu id
 *
 * Return the affine dpaa2_io service, or NULL if there is no service affined
 * to the specified cpu. If DPAA2_IO_ANY_CPU is used, return the next available
 * service.
 */
struct dpaa2_io *dpaa2_io_service_select(int cpu)
{
	if (cpu == DPAA2_IO_ANY_CPU)
		return service_select(NULL);

	return service_select_by_cpu(NULL, cpu);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_select);

/**
 * dpaa2_io_create() - create a dpaa2_io object.
 * @desc: the dpaa2_io descriptor
 * @dev: the actual DPIO device
 *
 * Activates a "struct dpaa2_io" corresponding to the given config of an actual
 * DPIO object.
 *
 * Return a valid dpaa2_io object for success, or NULL for failure.
 */
struct dpaa2_io *dpaa2_io_create(const struct dpaa2_io_desc *desc,
				 struct device *dev)
{
	struct dpaa2_io *obj = kmalloc(sizeof(*obj), GFP_KERNEL);

	if (!obj)
		return NULL;

	/* check if CPU is out of range (-1 means any cpu) */
	if (desc->cpu != DPAA2_IO_ANY_CPU && desc->cpu >= num_possible_cpus()) {
		kfree(obj);
		return NULL;
	}

	obj->dpio_desc = *desc;
	obj->swp_desc.cena_bar = obj->dpio_desc.regs_cena;
	obj->swp_desc.cinh_bar = obj->dpio_desc.regs_cinh;
	obj->swp_desc.qman_version = obj->dpio_desc.qman_version;
	obj->swp = qbman_swp_init(&obj->swp_desc);

	if (!obj->swp) {
		kfree(obj);
		return NULL;
	}

	INIT_LIST_HEAD(&obj->node);
	spin_lock_init(&obj->lock_mgmt_cmd);
	spin_lock_init(&obj->lock_notifications);
	INIT_LIST_HEAD(&obj->notifications);

	/* For now only enable DQRR interrupts */
	qbman_swp_interrupt_set_trigger(obj->swp,
					QBMAN_SWP_INTERRUPT_DQRI);
	qbman_swp_interrupt_clear_status(obj->swp, 0xffffffff);
	if (obj->dpio_desc.receives_notifications)
		qbman_swp_push_set(obj->swp, 0, 1);

	spin_lock(&dpio_list_lock);
	list_add_tail(&obj->node, &dpio_list);
	if (desc->cpu >= 0 && !dpio_by_cpu[desc->cpu])
		dpio_by_cpu[desc->cpu] = obj;
	spin_unlock(&dpio_list_lock);

	obj->dev = dev;

	return obj;
}

/**
 * dpaa2_io_down() - release the dpaa2_io object.
 * @d: the dpaa2_io object to be released.
 *
 * The "struct dpaa2_io" type can represent an individual DPIO object (as
 * described by "struct dpaa2_io_desc") or an instance of a "DPIO service",
 * which can be used to group/encapsulate multiple DPIO objects. In all cases,
 * each handle obtained should be released using this function.
 */
void dpaa2_io_down(struct dpaa2_io *d)
{
	spin_lock(&dpio_list_lock);
	dpio_by_cpu[d->dpio_desc.cpu] = NULL;
	list_del(&d->node);
	spin_unlock(&dpio_list_lock);

	kfree(d);
}

#define DPAA_POLL_MAX 32

/**
 * dpaa2_io_irq() - ISR for DPIO interrupts
 *
 * @obj: the given DPIO object.
 *
 * Return IRQ_HANDLED for success or IRQ_NONE if there
 * were no pending interrupts.
 */
irqreturn_t dpaa2_io_irq(struct dpaa2_io *obj)
{
	const struct dpaa2_dq *dq;
	int max = 0;
	struct qbman_swp *swp;
	u32 status;

	swp = obj->swp;
	status = qbman_swp_interrupt_read_status(swp);
	if (!status)
		return IRQ_NONE;

	dq = qbman_swp_dqrr_next(swp);
	while (dq) {
		if (qbman_result_is_SCN(dq)) {
			struct dpaa2_io_notification_ctx *ctx;
			u64 q64;

			q64 = qbman_result_SCN_ctx(dq);
			ctx = (void *)(uintptr_t)q64;
			ctx->cb(ctx);
		} else {
			pr_crit("fsl-mc-dpio: Unrecognised/ignored DQRR entry\n");
		}
		qbman_swp_dqrr_consume(swp, dq);
		++max;
		if (max > DPAA_POLL_MAX)
			goto done;
		dq = qbman_swp_dqrr_next(swp);
	}
done:
	qbman_swp_interrupt_clear_status(swp, status);
	qbman_swp_interrupt_set_inhibit(swp, 0);
	return IRQ_HANDLED;
}

/**
 * dpaa2_io_get_cpu() - get the cpu associated with a given DPIO object
 *
 * @d: the given DPIO object.
 *
 * Return the cpu associated with the DPIO object
 */
int dpaa2_io_get_cpu(struct dpaa2_io *d)
{
	return d->dpio_desc.cpu;
}
EXPORT_SYMBOL(dpaa2_io_get_cpu);

/**
 * dpaa2_io_service_register() - Prepare for servicing of FQDAN or CDAN
 *                               notifications on the given DPIO service.
 * @d:   the given DPIO service.
 * @ctx: the notification context.
 * @dev: the device that requests the register
 *
 * The caller should make the MC command to attach a DPAA2 object to
 * a DPIO after this function completes successfully.  In that way:
 *    (a) The DPIO service is "ready" to handle a notification arrival
 *        (which might happen before the "attach" command to MC has
 *        returned control of execution back to the caller)
 *    (b) The DPIO service can provide back to the caller the 'dpio_id' and
 *        'qman64' parameters that it should pass along in the MC command
 *        in order for the object to be configured to produce the right
 *        notification fields to the DPIO service.
 *
 * Return 0 for success, or -ENODEV for failure.
 */
int dpaa2_io_service_register(struct dpaa2_io *d,
			      struct dpaa2_io_notification_ctx *ctx,
			      struct device *dev)
{
	struct device_link *link;
	unsigned long irqflags;

	d = service_select_by_cpu(d, ctx->desired_cpu);
	if (!d)
		return -ENODEV;

	link = device_link_add(dev, d->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
	if (!link)
		return -EINVAL;

	ctx->dpio_id = d->dpio_desc.dpio_id;
	ctx->qman64 = (u64)(uintptr_t)ctx;
	ctx->dpio_private = d;
	spin_lock_irqsave(&d->lock_notifications, irqflags);
	list_add(&ctx->node, &d->notifications);
	spin_unlock_irqrestore(&d->lock_notifications, irqflags);

	/* Enable the generation of CDAN notifications */
	if (ctx->is_cdan)
		return qbman_swp_CDAN_set_context_enable(d->swp,
							 (u16)ctx->id,
							 ctx->qman64);
	return 0;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_register);

/**
 * dpaa2_io_service_deregister - The opposite of 'register'.
 * @service: the given DPIO service.
 * @ctx: the notification context.
 * @dev: the device that requests to be deregistered
 *
 * This function should be called only after sending the MC command to
 * to detach the notification-producing device from the DPIO.
 */
void dpaa2_io_service_deregister(struct dpaa2_io *service,
				 struct dpaa2_io_notification_ctx *ctx,
				 struct device *dev)
{
	struct dpaa2_io *d = ctx->dpio_private;
	unsigned long irqflags;

	if (ctx->is_cdan)
		qbman_swp_CDAN_disable(d->swp, (u16)ctx->id);

	spin_lock_irqsave(&d->lock_notifications, irqflags);
	list_del(&ctx->node);
	spin_unlock_irqrestore(&d->lock_notifications, irqflags);

}
EXPORT_SYMBOL_GPL(dpaa2_io_service_deregister);

/**
 * dpaa2_io_service_rearm() - Rearm the notification for the given DPIO service.
 * @d: the given DPIO service.
 * @ctx: the notification context.
 *
 * Once a FQDAN/CDAN has been produced, the corresponding FQ/channel is
 * considered "disarmed". Ie. the user can issue pull dequeue operations on that
 * traffic source for as long as it likes. Eventually it may wish to "rearm"
 * that source to allow it to produce another FQDAN/CDAN, that's what this
 * function achieves.
 *
 * Return 0 for success.
 */
int dpaa2_io_service_rearm(struct dpaa2_io *d,
			   struct dpaa2_io_notification_ctx *ctx)
{
	unsigned long irqflags;
	int err;

	d = service_select_by_cpu(d, ctx->desired_cpu);
	if (!unlikely(d))
		return -ENODEV;

	spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
	if (ctx->is_cdan)
		err = qbman_swp_CDAN_enable(d->swp, (u16)ctx->id);
	else
		err = qbman_swp_fq_schedule(d->swp, ctx->id);
	spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);

	return err;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_rearm);

/**
 * dpaa2_io_service_pull_fq() - pull dequeue functions from a fq.
 * @d: the given DPIO service.
 * @fqid: the given frame queue id.
 * @s: the dpaa2_io_store object for the result.
 *
 * Return 0 for success, or error code for failure.
 */
int dpaa2_io_service_pull_fq(struct dpaa2_io *d, u32 fqid,
			     struct dpaa2_io_store *s)
{
	struct qbman_pull_desc pd;
	int err;

	qbman_pull_desc_clear(&pd);
	qbman_pull_desc_set_storage(&pd, s->vaddr, s->paddr, 1);
	qbman_pull_desc_set_numframes(&pd, (u8)s->max);
	qbman_pull_desc_set_fq(&pd, fqid);

	d = service_select(d);
	if (!d)
		return -ENODEV;
	s->swp = d->swp;
	err = qbman_swp_pull(d->swp, &pd);
	if (err)
		s->swp = NULL;

	return err;
}
EXPORT_SYMBOL(dpaa2_io_service_pull_fq);

/**
 * dpaa2_io_service_pull_channel() - pull dequeue functions from a channel.
 * @d: the given DPIO service.
 * @channelid: the given channel id.
 * @s: the dpaa2_io_store object for the result.
 *
 * Return 0 for success, or error code for failure.
 */
int dpaa2_io_service_pull_channel(struct dpaa2_io *d, u32 channelid,
				  struct dpaa2_io_store *s)
{
	struct qbman_pull_desc pd;
	int err;

	qbman_pull_desc_clear(&pd);
	qbman_pull_desc_set_storage(&pd, s->vaddr, s->paddr, 1);
	qbman_pull_desc_set_numframes(&pd, (u8)s->max);
	qbman_pull_desc_set_channel(&pd, channelid, qbman_pull_type_prio);

	d = service_select(d);
	if (!d)
		return -ENODEV;

	s->swp = d->swp;
	err = qbman_swp_pull(d->swp, &pd);
	if (err)
		s->swp = NULL;

	return err;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_pull_channel);

/**
 * dpaa2_io_service_enqueue_fq() - Enqueue a frame to a frame queue.
 * @d: the given DPIO service.
 * @fqid: the given frame queue id.
 * @fd: the frame descriptor which is enqueued.
 *
 * Return 0 for successful enqueue, -EBUSY if the enqueue ring is not ready,
 * or -ENODEV if there is no dpio service.
 */
int dpaa2_io_service_enqueue_fq(struct dpaa2_io *d,
				u32 fqid,
				const struct dpaa2_fd *fd)
{
	struct qbman_eq_desc ed;

	d = service_select(d);
	if (!d)
		return -ENODEV;

	qbman_eq_desc_clear(&ed);
	qbman_eq_desc_set_no_orp(&ed, 0);
	qbman_eq_desc_set_fq(&ed, fqid);

	return qbman_swp_enqueue(d->swp, &ed, fd);
}
EXPORT_SYMBOL(dpaa2_io_service_enqueue_fq);

/**
 * dpaa2_io_service_enqueue_qd() - Enqueue a frame to a QD.
 * @d: the given DPIO service.
 * @qdid: the given queuing destination id.
 * @prio: the given queuing priority.
 * @qdbin: the given queuing destination bin.
 * @fd: the frame descriptor which is enqueued.
 *
 * Return 0 for successful enqueue, or -EBUSY if the enqueue ring is not ready,
 * or -ENODEV if there is no dpio service.
 */
int dpaa2_io_service_enqueue_qd(struct dpaa2_io *d,
				u32 qdid, u8 prio, u16 qdbin,
				const struct dpaa2_fd *fd)
{
	struct qbman_eq_desc ed;

	d = service_select(d);
	if (!d)
		return -ENODEV;

	qbman_eq_desc_clear(&ed);
	qbman_eq_desc_set_no_orp(&ed, 0);
	qbman_eq_desc_set_qd(&ed, qdid, qdbin, prio);

	return qbman_swp_enqueue(d->swp, &ed, fd);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_enqueue_qd);

/**
 * dpaa2_io_service_release() - Release buffers to a buffer pool.
 * @d: the given DPIO object.
 * @bpid: the buffer pool id.
 * @buffers: the buffers to be released.
 * @num_buffers: the number of the buffers to be released.
 *
 * Return 0 for success, and negative error code for failure.
 */
int dpaa2_io_service_release(struct dpaa2_io *d,
			     u16 bpid,
			     const u64 *buffers,
			     unsigned int num_buffers)
{
	struct qbman_release_desc rd;

	d = service_select(d);
	if (!d)
		return -ENODEV;

	qbman_release_desc_clear(&rd);
	qbman_release_desc_set_bpid(&rd, bpid);

	return qbman_swp_release(d->swp, &rd, buffers, num_buffers);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_release);

/**
 * dpaa2_io_service_acquire() - Acquire buffers from a buffer pool.
 * @d: the given DPIO object.
 * @bpid: the buffer pool id.
 * @buffers: the buffer addresses for acquired buffers.
 * @num_buffers: the expected number of the buffers to acquire.
 *
 * Return a negative error code if the command failed, otherwise it returns
 * the number of buffers acquired, which may be less than the number requested.
 * Eg. if the buffer pool is empty, this will return zero.
 */
int dpaa2_io_service_acquire(struct dpaa2_io *d,
			     u16 bpid,
			     u64 *buffers,
			     unsigned int num_buffers)
{
	unsigned long irqflags;
	int err;

	d = service_select(d);
	if (!d)
		return -ENODEV;

	spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
	err = qbman_swp_acquire(d->swp, bpid, buffers, num_buffers);
	spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);

	return err;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_acquire);

/*
 * 'Stores' are reusable memory blocks for holding dequeue results, and to
 * assist with parsing those results.
 */

/**
 * dpaa2_io_store_create() - Create the dma memory storage for dequeue result.
 * @max_frames: the maximum number of dequeued result for frames, must be <= 16.
 * @dev:        the device to allow mapping/unmapping the DMAable region.
 *
 * The size of the storage is "max_frames*sizeof(struct dpaa2_dq)".
 * The 'dpaa2_io_store' returned is a DPIO service managed object.
 *
 * Return pointer to dpaa2_io_store struct for successfully created storage
 * memory, or NULL on error.
 */
struct dpaa2_io_store *dpaa2_io_store_create(unsigned int max_frames,
					     struct device *dev)
{
	struct dpaa2_io_store *ret;
	size_t size;

	if (!max_frames || (max_frames > 16))
		return NULL;

	ret = kmalloc(sizeof(*ret), GFP_KERNEL);
	if (!ret)
		return NULL;

	ret->max = max_frames;
	size = max_frames * sizeof(struct dpaa2_dq) + 64;
	ret->alloced_addr = kzalloc(size, GFP_KERNEL);
	if (!ret->alloced_addr) {
		kfree(ret);
		return NULL;
	}

	ret->vaddr = PTR_ALIGN(ret->alloced_addr, 64);
	ret->paddr = dma_map_single(dev, ret->vaddr,
				    sizeof(struct dpaa2_dq) * max_frames,
				    DMA_FROM_DEVICE);
	if (dma_mapping_error(dev, ret->paddr)) {
		kfree(ret->alloced_addr);
		kfree(ret);
		return NULL;
	}

	ret->idx = 0;
	ret->dev = dev;

	return ret;
}
EXPORT_SYMBOL_GPL(dpaa2_io_store_create);

/**
 * dpaa2_io_store_destroy() - Frees the dma memory storage for dequeue
 *                            result.
 * @s: the storage memory to be destroyed.
 */
void dpaa2_io_store_destroy(struct dpaa2_io_store *s)
{
	dma_unmap_single(s->dev, s->paddr, sizeof(struct dpaa2_dq) * s->max,
			 DMA_FROM_DEVICE);
	kfree(s->alloced_addr);
	kfree(s);
}
EXPORT_SYMBOL_GPL(dpaa2_io_store_destroy);

/**
 * dpaa2_io_store_next() - Determine when the next dequeue result is available.
 * @s: the dpaa2_io_store object.
 * @is_last: indicate whether this is the last frame in the pull command.
 *
 * When an object driver performs dequeues to a dpaa2_io_store, this function
 * can be used to determine when the next frame result is available. Once
 * this function returns non-NULL, a subsequent call to it will try to find
 * the next dequeue result.
 *
 * Note that if a pull-dequeue has a NULL result because the target FQ/channel
 * was empty, then this function will also return NULL (rather than expecting
 * the caller to always check for this. As such, "is_last" can be used to
 * differentiate between "end-of-empty-dequeue" and "still-waiting".
 *
 * Return dequeue result for a valid dequeue result, or NULL for empty dequeue.
 */
struct dpaa2_dq *dpaa2_io_store_next(struct dpaa2_io_store *s, int *is_last)
{
	int match;
	struct dpaa2_dq *ret = &s->vaddr[s->idx];

	match = qbman_result_has_new_result(s->swp, ret);
	if (!match) {
		*is_last = 0;
		return NULL;
	}

	s->idx++;

	if (dpaa2_dq_is_pull_complete(ret)) {
		*is_last = 1;
		s->idx = 0;
		/*
		 * If we get an empty dequeue result to terminate a zero-results
		 * vdqcr, return NULL to the caller rather than expecting him to
		 * check non-NULL results every time.
		 */
		if (!(dpaa2_dq_flags(ret) & DPAA2_DQ_STAT_VALIDFRAME))
			ret = NULL;
	} else {
		prefetch(&s->vaddr[s->idx]);
		*is_last = 0;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(dpaa2_io_store_next);

/**
 * dpaa2_io_query_fq_count() - Get the frame and byte count for a given fq.
 * @d: the given DPIO object.
 * @fqid: the id of frame queue to be queried.
 * @fcnt: the queried frame count.
 * @bcnt: the queried byte count.
 *
 * Knowing the FQ count at run-time can be useful in debugging situations.
 * The instantaneous frame- and byte-count are hereby returned.
 *
 * Return 0 for a successful query, and negative error code if query fails.
 */
int dpaa2_io_query_fq_count(struct dpaa2_io *d, u32 fqid,
			    u32 *fcnt, u32 *bcnt)
{
	struct qbman_fq_query_np_rslt state;
	struct qbman_swp *swp;
	unsigned long irqflags;
	int ret;

	d = service_select(d);
	if (!d)
		return -ENODEV;

	swp = d->swp;
	spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
	ret = qbman_fq_query_state(swp, fqid, &state);
	spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);
	if (ret)
		return ret;
	*fcnt = qbman_fq_state_frame_count(&state);
	*bcnt = qbman_fq_state_byte_count(&state);

	return 0;
}
EXPORT_SYMBOL_GPL(dpaa2_io_query_fq_count);

/**
 * dpaa2_io_query_bp_count() - Query the number of buffers currently in a
 * buffer pool.
 * @d: the given DPIO object.
 * @bpid: the index of buffer pool to be queried.
 * @num: the queried number of buffers in the buffer pool.
 *
 * Return 0 for a successful query, and negative error code if query fails.
 */
int dpaa2_io_query_bp_count(struct dpaa2_io *d, u16 bpid, u32 *num)
{
	struct qbman_bp_query_rslt state;
	struct qbman_swp *swp;
	unsigned long irqflags;
	int ret;

	d = service_select(d);
	if (!d)
		return -ENODEV;

	swp = d->swp;
	spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
	ret = qbman_bp_query(swp, bpid, &state);
	spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);
	if (ret)
		return ret;
	*num = qbman_bp_info_num_free_bufs(&state);
	return 0;
}
EXPORT_SYMBOL_GPL(dpaa2_io_query_bp_count);