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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Virtio memory mapped device driver
4 *
5 * Copyright 2011-2014, ARM Ltd.
6 *
7 * This module allows virtio devices to be used over a virtual, memory mapped
8 * platform device.
9 *
10 * The guest device(s) may be instantiated in one of three equivalent ways:
11 *
12 * 1. Static platform device in board's code, eg.:
13 *
14 * static struct platform_device v2m_virtio_device = {
15 * .name = "virtio-mmio",
16 * .id = -1,
17 * .num_resources = 2,
18 * .resource = (struct resource []) {
19 * {
20 * .start = 0x1001e000,
21 * .end = 0x1001e0ff,
22 * .flags = IORESOURCE_MEM,
23 * }, {
24 * .start = 42 + 32,
25 * .end = 42 + 32,
26 * .flags = IORESOURCE_IRQ,
27 * },
28 * }
29 * };
30 *
31 * 2. Device Tree node, eg.:
32 *
33 * virtio_block@1e000 {
34 * compatible = "virtio,mmio";
35 * reg = <0x1e000 0x100>;
36 * interrupts = <42>;
37 * }
38 *
39 * 3. Kernel module (or command line) parameter. Can be used more than once -
40 * one device will be created for each one. Syntax:
41 *
42 * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>]
43 * where:
44 * <size> := size (can use standard suffixes like K, M or G)
45 * <baseaddr> := physical base address
46 * <irq> := interrupt number (as passed to request_irq())
47 * <id> := (optional) platform device id
48 * eg.:
49 * virtio_mmio.device=0x100@0x100b0000:48 \
50 * virtio_mmio.device=1K@0x1001e000:74
51 *
52 * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
53 */
54
55#define pr_fmt(fmt) "virtio-mmio: " fmt
56
57#include <linux/acpi.h>
58#include <linux/dma-mapping.h>
59#include <linux/highmem.h>
60#include <linux/interrupt.h>
61#include <linux/io.h>
62#include <linux/list.h>
63#include <linux/module.h>
64#include <linux/platform_device.h>
65#include <linux/slab.h>
66#include <linux/spinlock.h>
67#include <linux/virtio.h>
68#include <linux/virtio_config.h>
69#include <uapi/linux/virtio_mmio.h>
70#include <linux/virtio_ring.h>
71
72
73
74/* The alignment to use between consumer and producer parts of vring.
75 * Currently hardcoded to the page size. */
76#define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
77
78
79
80#define to_virtio_mmio_device(_plat_dev) \
81 container_of(_plat_dev, struct virtio_mmio_device, vdev)
82
83struct virtio_mmio_device {
84 struct virtio_device vdev;
85 struct platform_device *pdev;
86
87 void __iomem *base;
88 unsigned long version;
89
90 /* a list of queues so we can dispatch IRQs */
91 spinlock_t lock;
92 struct list_head virtqueues;
93};
94
95struct virtio_mmio_vq_info {
96 /* the actual virtqueue */
97 struct virtqueue *vq;
98
99 /* the list node for the virtqueues list */
100 struct list_head node;
101};
102
103
104
105/* Configuration interface */
106
107static u64 vm_get_features(struct virtio_device *vdev)
108{
109 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
110 u64 features;
111
112 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
113 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
114 features <<= 32;
115
116 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
117 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
118
119 return features;
120}
121
122static int vm_finalize_features(struct virtio_device *vdev)
123{
124 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
125
126 /* Give virtio_ring a chance to accept features. */
127 vring_transport_features(vdev);
128
129 /* Make sure there is are no mixed devices */
130 if (vm_dev->version == 2 &&
131 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
132 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
133 return -EINVAL;
134 }
135
136 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
137 writel((u32)(vdev->features >> 32),
138 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
139
140 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
141 writel((u32)vdev->features,
142 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
143
144 return 0;
145}
146
147static void vm_get(struct virtio_device *vdev, unsigned offset,
148 void *buf, unsigned len)
149{
150 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
151 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
152 u8 b;
153 __le16 w;
154 __le32 l;
155
156 if (vm_dev->version == 1) {
157 u8 *ptr = buf;
158 int i;
159
160 for (i = 0; i < len; i++)
161 ptr[i] = readb(base + offset + i);
162 return;
163 }
164
165 switch (len) {
166 case 1:
167 b = readb(base + offset);
168 memcpy(buf, &b, sizeof b);
169 break;
170 case 2:
171 w = cpu_to_le16(readw(base + offset));
172 memcpy(buf, &w, sizeof w);
173 break;
174 case 4:
175 l = cpu_to_le32(readl(base + offset));
176 memcpy(buf, &l, sizeof l);
177 break;
178 case 8:
179 l = cpu_to_le32(readl(base + offset));
180 memcpy(buf, &l, sizeof l);
181 l = cpu_to_le32(ioread32(base + offset + sizeof l));
182 memcpy(buf + sizeof l, &l, sizeof l);
183 break;
184 default:
185 BUG();
186 }
187}
188
189static void vm_set(struct virtio_device *vdev, unsigned offset,
190 const void *buf, unsigned len)
191{
192 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
193 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
194 u8 b;
195 __le16 w;
196 __le32 l;
197
198 if (vm_dev->version == 1) {
199 const u8 *ptr = buf;
200 int i;
201
202 for (i = 0; i < len; i++)
203 writeb(ptr[i], base + offset + i);
204
205 return;
206 }
207
208 switch (len) {
209 case 1:
210 memcpy(&b, buf, sizeof b);
211 writeb(b, base + offset);
212 break;
213 case 2:
214 memcpy(&w, buf, sizeof w);
215 writew(le16_to_cpu(w), base + offset);
216 break;
217 case 4:
218 memcpy(&l, buf, sizeof l);
219 writel(le32_to_cpu(l), base + offset);
220 break;
221 case 8:
222 memcpy(&l, buf, sizeof l);
223 writel(le32_to_cpu(l), base + offset);
224 memcpy(&l, buf + sizeof l, sizeof l);
225 writel(le32_to_cpu(l), base + offset + sizeof l);
226 break;
227 default:
228 BUG();
229 }
230}
231
232static u32 vm_generation(struct virtio_device *vdev)
233{
234 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
235
236 if (vm_dev->version == 1)
237 return 0;
238 else
239 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
240}
241
242static u8 vm_get_status(struct virtio_device *vdev)
243{
244 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
245
246 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
247}
248
249static void vm_set_status(struct virtio_device *vdev, u8 status)
250{
251 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
252
253 /* We should never be setting status to 0. */
254 BUG_ON(status == 0);
255
256 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
257}
258
259static void vm_reset(struct virtio_device *vdev)
260{
261 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
262
263 /* 0 status means a reset. */
264 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
265}
266
267
268
269/* Transport interface */
270
271/* the notify function used when creating a virt queue */
272static bool vm_notify(struct virtqueue *vq)
273{
274 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
275
276 /* We write the queue's selector into the notification register to
277 * signal the other end */
278 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
279 return true;
280}
281
282/* Notify all virtqueues on an interrupt. */
283static irqreturn_t vm_interrupt(int irq, void *opaque)
284{
285 struct virtio_mmio_device *vm_dev = opaque;
286 struct virtio_mmio_vq_info *info;
287 unsigned long status;
288 unsigned long flags;
289 irqreturn_t ret = IRQ_NONE;
290
291 /* Read and acknowledge interrupts */
292 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
293 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
294
295 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
296 virtio_config_changed(&vm_dev->vdev);
297 ret = IRQ_HANDLED;
298 }
299
300 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
301 spin_lock_irqsave(&vm_dev->lock, flags);
302 list_for_each_entry(info, &vm_dev->virtqueues, node)
303 ret |= vring_interrupt(irq, info->vq);
304 spin_unlock_irqrestore(&vm_dev->lock, flags);
305 }
306
307 return ret;
308}
309
310
311
312static void vm_del_vq(struct virtqueue *vq)
313{
314 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
315 struct virtio_mmio_vq_info *info = vq->priv;
316 unsigned long flags;
317 unsigned int index = vq->index;
318
319 spin_lock_irqsave(&vm_dev->lock, flags);
320 list_del(&info->node);
321 spin_unlock_irqrestore(&vm_dev->lock, flags);
322
323 /* Select and deactivate the queue */
324 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
325 if (vm_dev->version == 1) {
326 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
327 } else {
328 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
329 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
330 }
331
332 vring_del_virtqueue(vq);
333
334 kfree(info);
335}
336
337static void vm_del_vqs(struct virtio_device *vdev)
338{
339 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
340 struct virtqueue *vq, *n;
341
342 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
343 vm_del_vq(vq);
344
345 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
346}
347
348static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
349 void (*callback)(struct virtqueue *vq),
350 const char *name, bool ctx)
351{
352 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
353 struct virtio_mmio_vq_info *info;
354 struct virtqueue *vq;
355 unsigned long flags;
356 unsigned int num;
357 int err;
358
359 if (!name)
360 return NULL;
361
362 /* Select the queue we're interested in */
363 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
364
365 /* Queue shouldn't already be set up. */
366 if (readl(vm_dev->base + (vm_dev->version == 1 ?
367 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
368 err = -ENOENT;
369 goto error_available;
370 }
371
372 /* Allocate and fill out our active queue description */
373 info = kmalloc(sizeof(*info), GFP_KERNEL);
374 if (!info) {
375 err = -ENOMEM;
376 goto error_kmalloc;
377 }
378
379 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
380 if (num == 0) {
381 err = -ENOENT;
382 goto error_new_virtqueue;
383 }
384
385 /* Create the vring */
386 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
387 true, true, ctx, vm_notify, callback, name);
388 if (!vq) {
389 err = -ENOMEM;
390 goto error_new_virtqueue;
391 }
392
393 /* Activate the queue */
394 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
395 if (vm_dev->version == 1) {
396 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
397
398 /*
399 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
400 * that doesn't fit in 32bit, fail the setup rather than
401 * pretending to be successful.
402 */
403 if (q_pfn >> 32) {
404 dev_err(&vdev->dev,
405 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
406 0x1ULL << (32 + PAGE_SHIFT - 30));
407 err = -E2BIG;
408 goto error_bad_pfn;
409 }
410
411 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
412 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
413 } else {
414 u64 addr;
415
416 addr = virtqueue_get_desc_addr(vq);
417 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
418 writel((u32)(addr >> 32),
419 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
420
421 addr = virtqueue_get_avail_addr(vq);
422 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
423 writel((u32)(addr >> 32),
424 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
425
426 addr = virtqueue_get_used_addr(vq);
427 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
428 writel((u32)(addr >> 32),
429 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
430
431 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
432 }
433
434 vq->priv = info;
435 info->vq = vq;
436
437 spin_lock_irqsave(&vm_dev->lock, flags);
438 list_add(&info->node, &vm_dev->virtqueues);
439 spin_unlock_irqrestore(&vm_dev->lock, flags);
440
441 return vq;
442
443error_bad_pfn:
444 vring_del_virtqueue(vq);
445error_new_virtqueue:
446 if (vm_dev->version == 1) {
447 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
448 } else {
449 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
450 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
451 }
452 kfree(info);
453error_kmalloc:
454error_available:
455 return ERR_PTR(err);
456}
457
458static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
459 struct virtqueue *vqs[],
460 vq_callback_t *callbacks[],
461 const char * const names[],
462 const bool *ctx,
463 struct irq_affinity *desc)
464{
465 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
466 int irq = platform_get_irq(vm_dev->pdev, 0);
467 int i, err, queue_idx = 0;
468
469 if (irq < 0)
470 return irq;
471
472 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
473 dev_name(&vdev->dev), vm_dev);
474 if (err)
475 return err;
476
477 for (i = 0; i < nvqs; ++i) {
478 if (!names[i]) {
479 vqs[i] = NULL;
480 continue;
481 }
482
483 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
484 ctx ? ctx[i] : false);
485 if (IS_ERR(vqs[i])) {
486 vm_del_vqs(vdev);
487 return PTR_ERR(vqs[i]);
488 }
489 }
490
491 return 0;
492}
493
494static const char *vm_bus_name(struct virtio_device *vdev)
495{
496 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
497
498 return vm_dev->pdev->name;
499}
500
501static const struct virtio_config_ops virtio_mmio_config_ops = {
502 .get = vm_get,
503 .set = vm_set,
504 .generation = vm_generation,
505 .get_status = vm_get_status,
506 .set_status = vm_set_status,
507 .reset = vm_reset,
508 .find_vqs = vm_find_vqs,
509 .del_vqs = vm_del_vqs,
510 .get_features = vm_get_features,
511 .finalize_features = vm_finalize_features,
512 .bus_name = vm_bus_name,
513};
514
515
516static void virtio_mmio_release_dev(struct device *_d)
517{
518 struct virtio_device *vdev =
519 container_of(_d, struct virtio_device, dev);
520 struct virtio_mmio_device *vm_dev =
521 container_of(vdev, struct virtio_mmio_device, vdev);
522 struct platform_device *pdev = vm_dev->pdev;
523
524 devm_kfree(&pdev->dev, vm_dev);
525}
526
527/* Platform device */
528
529static int virtio_mmio_probe(struct platform_device *pdev)
530{
531 struct virtio_mmio_device *vm_dev;
532 unsigned long magic;
533 int rc;
534
535 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
536 if (!vm_dev)
537 return -ENOMEM;
538
539 vm_dev->vdev.dev.parent = &pdev->dev;
540 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
541 vm_dev->vdev.config = &virtio_mmio_config_ops;
542 vm_dev->pdev = pdev;
543 INIT_LIST_HEAD(&vm_dev->virtqueues);
544 spin_lock_init(&vm_dev->lock);
545
546 vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
547 if (IS_ERR(vm_dev->base))
548 return PTR_ERR(vm_dev->base);
549
550 /* Check magic value */
551 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
552 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
553 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
554 return -ENODEV;
555 }
556
557 /* Check device version */
558 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
559 if (vm_dev->version < 1 || vm_dev->version > 2) {
560 dev_err(&pdev->dev, "Version %ld not supported!\n",
561 vm_dev->version);
562 return -ENXIO;
563 }
564
565 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
566 if (vm_dev->vdev.id.device == 0) {
567 /*
568 * virtio-mmio device with an ID 0 is a (dummy) placeholder
569 * with no function. End probing now with no error reported.
570 */
571 return -ENODEV;
572 }
573 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
574
575 if (vm_dev->version == 1) {
576 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
577
578 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
579 /*
580 * In the legacy case, ensure our coherently-allocated virtio
581 * ring will be at an address expressable as a 32-bit PFN.
582 */
583 if (!rc)
584 dma_set_coherent_mask(&pdev->dev,
585 DMA_BIT_MASK(32 + PAGE_SHIFT));
586 } else {
587 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
588 }
589 if (rc)
590 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
591 if (rc)
592 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
593
594 platform_set_drvdata(pdev, vm_dev);
595
596 rc = register_virtio_device(&vm_dev->vdev);
597 if (rc)
598 put_device(&vm_dev->vdev.dev);
599
600 return rc;
601}
602
603static int virtio_mmio_remove(struct platform_device *pdev)
604{
605 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
606 unregister_virtio_device(&vm_dev->vdev);
607
608 return 0;
609}
610
611
612
613/* Devices list parameter */
614
615#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
616
617static struct device vm_cmdline_parent = {
618 .init_name = "virtio-mmio-cmdline",
619};
620
621static int vm_cmdline_parent_registered;
622static int vm_cmdline_id;
623
624static int vm_cmdline_set(const char *device,
625 const struct kernel_param *kp)
626{
627 int err;
628 struct resource resources[2] = {};
629 char *str;
630 long long int base, size;
631 unsigned int irq;
632 int processed, consumed = 0;
633 struct platform_device *pdev;
634
635 /* Consume "size" part of the command line parameter */
636 size = memparse(device, &str);
637
638 /* Get "@<base>:<irq>[:<id>]" chunks */
639 processed = sscanf(str, "@%lli:%u%n:%d%n",
640 &base, &irq, &consumed,
641 &vm_cmdline_id, &consumed);
642
643 /*
644 * sscanf() must process at least 2 chunks; also there
645 * must be no extra characters after the last chunk, so
646 * str[consumed] must be '\0'
647 */
648 if (processed < 2 || str[consumed] || irq == 0)
649 return -EINVAL;
650
651 resources[0].flags = IORESOURCE_MEM;
652 resources[0].start = base;
653 resources[0].end = base + size - 1;
654
655 resources[1].flags = IORESOURCE_IRQ;
656 resources[1].start = resources[1].end = irq;
657
658 if (!vm_cmdline_parent_registered) {
659 err = device_register(&vm_cmdline_parent);
660 if (err) {
661 pr_err("Failed to register parent device!\n");
662 return err;
663 }
664 vm_cmdline_parent_registered = 1;
665 }
666
667 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
668 vm_cmdline_id,
669 (unsigned long long)resources[0].start,
670 (unsigned long long)resources[0].end,
671 (int)resources[1].start);
672
673 pdev = platform_device_register_resndata(&vm_cmdline_parent,
674 "virtio-mmio", vm_cmdline_id++,
675 resources, ARRAY_SIZE(resources), NULL, 0);
676
677 return PTR_ERR_OR_ZERO(pdev);
678}
679
680static int vm_cmdline_get_device(struct device *dev, void *data)
681{
682 char *buffer = data;
683 unsigned int len = strlen(buffer);
684 struct platform_device *pdev = to_platform_device(dev);
685
686 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
687 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
688 (unsigned long long)pdev->resource[0].start,
689 (unsigned long long)pdev->resource[1].start,
690 pdev->id);
691 return 0;
692}
693
694static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
695{
696 buffer[0] = '\0';
697 device_for_each_child(&vm_cmdline_parent, buffer,
698 vm_cmdline_get_device);
699 return strlen(buffer) + 1;
700}
701
702static const struct kernel_param_ops vm_cmdline_param_ops = {
703 .set = vm_cmdline_set,
704 .get = vm_cmdline_get,
705};
706
707device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
708
709static int vm_unregister_cmdline_device(struct device *dev,
710 void *data)
711{
712 platform_device_unregister(to_platform_device(dev));
713
714 return 0;
715}
716
717static void vm_unregister_cmdline_devices(void)
718{
719 if (vm_cmdline_parent_registered) {
720 device_for_each_child(&vm_cmdline_parent, NULL,
721 vm_unregister_cmdline_device);
722 device_unregister(&vm_cmdline_parent);
723 vm_cmdline_parent_registered = 0;
724 }
725}
726
727#else
728
729static void vm_unregister_cmdline_devices(void)
730{
731}
732
733#endif
734
735/* Platform driver */
736
737static const struct of_device_id virtio_mmio_match[] = {
738 { .compatible = "virtio,mmio", },
739 {},
740};
741MODULE_DEVICE_TABLE(of, virtio_mmio_match);
742
743#ifdef CONFIG_ACPI
744static const struct acpi_device_id virtio_mmio_acpi_match[] = {
745 { "LNRO0005", },
746 { }
747};
748MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
749#endif
750
751static struct platform_driver virtio_mmio_driver = {
752 .probe = virtio_mmio_probe,
753 .remove = virtio_mmio_remove,
754 .driver = {
755 .name = "virtio-mmio",
756 .of_match_table = virtio_mmio_match,
757 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
758 },
759};
760
761static int __init virtio_mmio_init(void)
762{
763 return platform_driver_register(&virtio_mmio_driver);
764}
765
766static void __exit virtio_mmio_exit(void)
767{
768 platform_driver_unregister(&virtio_mmio_driver);
769 vm_unregister_cmdline_devices();
770}
771
772module_init(virtio_mmio_init);
773module_exit(virtio_mmio_exit);
774
775MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
776MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
777MODULE_LICENSE("GPL");
1/*
2 * Virtio memory mapped device driver
3 *
4 * Copyright 2011-2014, ARM Ltd.
5 *
6 * This module allows virtio devices to be used over a virtual, memory mapped
7 * platform device.
8 *
9 * The guest device(s) may be instantiated in one of three equivalent ways:
10 *
11 * 1. Static platform device in board's code, eg.:
12 *
13 * static struct platform_device v2m_virtio_device = {
14 * .name = "virtio-mmio",
15 * .id = -1,
16 * .num_resources = 2,
17 * .resource = (struct resource []) {
18 * {
19 * .start = 0x1001e000,
20 * .end = 0x1001e0ff,
21 * .flags = IORESOURCE_MEM,
22 * }, {
23 * .start = 42 + 32,
24 * .end = 42 + 32,
25 * .flags = IORESOURCE_IRQ,
26 * },
27 * }
28 * };
29 *
30 * 2. Device Tree node, eg.:
31 *
32 * virtio_block@1e000 {
33 * compatible = "virtio,mmio";
34 * reg = <0x1e000 0x100>;
35 * interrupts = <42>;
36 * }
37 *
38 * 3. Kernel module (or command line) parameter. Can be used more than once -
39 * one device will be created for each one. Syntax:
40 *
41 * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>]
42 * where:
43 * <size> := size (can use standard suffixes like K, M or G)
44 * <baseaddr> := physical base address
45 * <irq> := interrupt number (as passed to request_irq())
46 * <id> := (optional) platform device id
47 * eg.:
48 * virtio_mmio.device=0x100@0x100b0000:48 \
49 * virtio_mmio.device=1K@0x1001e000:74
50 *
51 *
52 *
53 * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
54 *
55 * This work is licensed under the terms of the GNU GPL, version 2 or later.
56 * See the COPYING file in the top-level directory.
57 */
58
59#define pr_fmt(fmt) "virtio-mmio: " fmt
60
61#include <linux/acpi.h>
62#include <linux/dma-mapping.h>
63#include <linux/highmem.h>
64#include <linux/interrupt.h>
65#include <linux/io.h>
66#include <linux/list.h>
67#include <linux/module.h>
68#include <linux/platform_device.h>
69#include <linux/slab.h>
70#include <linux/spinlock.h>
71#include <linux/virtio.h>
72#include <linux/virtio_config.h>
73#include <uapi/linux/virtio_mmio.h>
74#include <linux/virtio_ring.h>
75
76
77
78/* The alignment to use between consumer and producer parts of vring.
79 * Currently hardcoded to the page size. */
80#define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
81
82
83
84#define to_virtio_mmio_device(_plat_dev) \
85 container_of(_plat_dev, struct virtio_mmio_device, vdev)
86
87struct virtio_mmio_device {
88 struct virtio_device vdev;
89 struct platform_device *pdev;
90
91 void __iomem *base;
92 unsigned long version;
93
94 /* a list of queues so we can dispatch IRQs */
95 spinlock_t lock;
96 struct list_head virtqueues;
97};
98
99struct virtio_mmio_vq_info {
100 /* the actual virtqueue */
101 struct virtqueue *vq;
102
103 /* the list node for the virtqueues list */
104 struct list_head node;
105};
106
107
108
109/* Configuration interface */
110
111static u64 vm_get_features(struct virtio_device *vdev)
112{
113 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
114 u64 features;
115
116 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
117 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
118 features <<= 32;
119
120 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
121 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
122
123 return features;
124}
125
126static int vm_finalize_features(struct virtio_device *vdev)
127{
128 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
129
130 /* Give virtio_ring a chance to accept features. */
131 vring_transport_features(vdev);
132
133 /* Make sure there is are no mixed devices */
134 if (vm_dev->version == 2 &&
135 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
136 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
137 return -EINVAL;
138 }
139
140 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
141 writel((u32)(vdev->features >> 32),
142 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
143
144 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
145 writel((u32)vdev->features,
146 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
147
148 return 0;
149}
150
151static void vm_get(struct virtio_device *vdev, unsigned offset,
152 void *buf, unsigned len)
153{
154 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
155 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
156 u8 b;
157 __le16 w;
158 __le32 l;
159
160 if (vm_dev->version == 1) {
161 u8 *ptr = buf;
162 int i;
163
164 for (i = 0; i < len; i++)
165 ptr[i] = readb(base + offset + i);
166 return;
167 }
168
169 switch (len) {
170 case 1:
171 b = readb(base + offset);
172 memcpy(buf, &b, sizeof b);
173 break;
174 case 2:
175 w = cpu_to_le16(readw(base + offset));
176 memcpy(buf, &w, sizeof w);
177 break;
178 case 4:
179 l = cpu_to_le32(readl(base + offset));
180 memcpy(buf, &l, sizeof l);
181 break;
182 case 8:
183 l = cpu_to_le32(readl(base + offset));
184 memcpy(buf, &l, sizeof l);
185 l = cpu_to_le32(ioread32(base + offset + sizeof l));
186 memcpy(buf + sizeof l, &l, sizeof l);
187 break;
188 default:
189 BUG();
190 }
191}
192
193static void vm_set(struct virtio_device *vdev, unsigned offset,
194 const void *buf, unsigned len)
195{
196 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
197 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
198 u8 b;
199 __le16 w;
200 __le32 l;
201
202 if (vm_dev->version == 1) {
203 const u8 *ptr = buf;
204 int i;
205
206 for (i = 0; i < len; i++)
207 writeb(ptr[i], base + offset + i);
208
209 return;
210 }
211
212 switch (len) {
213 case 1:
214 memcpy(&b, buf, sizeof b);
215 writeb(b, base + offset);
216 break;
217 case 2:
218 memcpy(&w, buf, sizeof w);
219 writew(le16_to_cpu(w), base + offset);
220 break;
221 case 4:
222 memcpy(&l, buf, sizeof l);
223 writel(le32_to_cpu(l), base + offset);
224 break;
225 case 8:
226 memcpy(&l, buf, sizeof l);
227 writel(le32_to_cpu(l), base + offset);
228 memcpy(&l, buf + sizeof l, sizeof l);
229 writel(le32_to_cpu(l), base + offset + sizeof l);
230 break;
231 default:
232 BUG();
233 }
234}
235
236static u32 vm_generation(struct virtio_device *vdev)
237{
238 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
239
240 if (vm_dev->version == 1)
241 return 0;
242 else
243 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
244}
245
246static u8 vm_get_status(struct virtio_device *vdev)
247{
248 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
249
250 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
251}
252
253static void vm_set_status(struct virtio_device *vdev, u8 status)
254{
255 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
256
257 /* We should never be setting status to 0. */
258 BUG_ON(status == 0);
259
260 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
261}
262
263static void vm_reset(struct virtio_device *vdev)
264{
265 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
266
267 /* 0 status means a reset. */
268 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
269}
270
271
272
273/* Transport interface */
274
275/* the notify function used when creating a virt queue */
276static bool vm_notify(struct virtqueue *vq)
277{
278 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
279
280 /* We write the queue's selector into the notification register to
281 * signal the other end */
282 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
283 return true;
284}
285
286/* Notify all virtqueues on an interrupt. */
287static irqreturn_t vm_interrupt(int irq, void *opaque)
288{
289 struct virtio_mmio_device *vm_dev = opaque;
290 struct virtio_mmio_vq_info *info;
291 unsigned long status;
292 unsigned long flags;
293 irqreturn_t ret = IRQ_NONE;
294
295 /* Read and acknowledge interrupts */
296 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
297 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
298
299 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
300 virtio_config_changed(&vm_dev->vdev);
301 ret = IRQ_HANDLED;
302 }
303
304 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
305 spin_lock_irqsave(&vm_dev->lock, flags);
306 list_for_each_entry(info, &vm_dev->virtqueues, node)
307 ret |= vring_interrupt(irq, info->vq);
308 spin_unlock_irqrestore(&vm_dev->lock, flags);
309 }
310
311 return ret;
312}
313
314
315
316static void vm_del_vq(struct virtqueue *vq)
317{
318 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
319 struct virtio_mmio_vq_info *info = vq->priv;
320 unsigned long flags;
321 unsigned int index = vq->index;
322
323 spin_lock_irqsave(&vm_dev->lock, flags);
324 list_del(&info->node);
325 spin_unlock_irqrestore(&vm_dev->lock, flags);
326
327 /* Select and deactivate the queue */
328 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
329 if (vm_dev->version == 1) {
330 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
331 } else {
332 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
333 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
334 }
335
336 vring_del_virtqueue(vq);
337
338 kfree(info);
339}
340
341static void vm_del_vqs(struct virtio_device *vdev)
342{
343 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
344 struct virtqueue *vq, *n;
345
346 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
347 vm_del_vq(vq);
348
349 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
350}
351
352static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
353 void (*callback)(struct virtqueue *vq),
354 const char *name, bool ctx)
355{
356 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
357 struct virtio_mmio_vq_info *info;
358 struct virtqueue *vq;
359 unsigned long flags;
360 unsigned int num;
361 int err;
362
363 if (!name)
364 return NULL;
365
366 /* Select the queue we're interested in */
367 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
368
369 /* Queue shouldn't already be set up. */
370 if (readl(vm_dev->base + (vm_dev->version == 1 ?
371 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
372 err = -ENOENT;
373 goto error_available;
374 }
375
376 /* Allocate and fill out our active queue description */
377 info = kmalloc(sizeof(*info), GFP_KERNEL);
378 if (!info) {
379 err = -ENOMEM;
380 goto error_kmalloc;
381 }
382
383 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
384 if (num == 0) {
385 err = -ENOENT;
386 goto error_new_virtqueue;
387 }
388
389 /* Create the vring */
390 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
391 true, true, ctx, vm_notify, callback, name);
392 if (!vq) {
393 err = -ENOMEM;
394 goto error_new_virtqueue;
395 }
396
397 /* Activate the queue */
398 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
399 if (vm_dev->version == 1) {
400 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
401 writel(virtqueue_get_desc_addr(vq) >> PAGE_SHIFT,
402 vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
403 } else {
404 u64 addr;
405
406 addr = virtqueue_get_desc_addr(vq);
407 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
408 writel((u32)(addr >> 32),
409 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
410
411 addr = virtqueue_get_avail_addr(vq);
412 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
413 writel((u32)(addr >> 32),
414 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
415
416 addr = virtqueue_get_used_addr(vq);
417 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
418 writel((u32)(addr >> 32),
419 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
420
421 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
422 }
423
424 vq->priv = info;
425 info->vq = vq;
426
427 spin_lock_irqsave(&vm_dev->lock, flags);
428 list_add(&info->node, &vm_dev->virtqueues);
429 spin_unlock_irqrestore(&vm_dev->lock, flags);
430
431 return vq;
432
433error_new_virtqueue:
434 if (vm_dev->version == 1) {
435 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
436 } else {
437 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
438 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
439 }
440 kfree(info);
441error_kmalloc:
442error_available:
443 return ERR_PTR(err);
444}
445
446static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
447 struct virtqueue *vqs[],
448 vq_callback_t *callbacks[],
449 const char * const names[],
450 const bool *ctx,
451 struct irq_affinity *desc)
452{
453 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
454 unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
455 int i, err;
456
457 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
458 dev_name(&vdev->dev), vm_dev);
459 if (err)
460 return err;
461
462 for (i = 0; i < nvqs; ++i) {
463 vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i],
464 ctx ? ctx[i] : false);
465 if (IS_ERR(vqs[i])) {
466 vm_del_vqs(vdev);
467 return PTR_ERR(vqs[i]);
468 }
469 }
470
471 return 0;
472}
473
474static const char *vm_bus_name(struct virtio_device *vdev)
475{
476 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
477
478 return vm_dev->pdev->name;
479}
480
481static const struct virtio_config_ops virtio_mmio_config_ops = {
482 .get = vm_get,
483 .set = vm_set,
484 .generation = vm_generation,
485 .get_status = vm_get_status,
486 .set_status = vm_set_status,
487 .reset = vm_reset,
488 .find_vqs = vm_find_vqs,
489 .del_vqs = vm_del_vqs,
490 .get_features = vm_get_features,
491 .finalize_features = vm_finalize_features,
492 .bus_name = vm_bus_name,
493};
494
495
496static void virtio_mmio_release_dev(struct device *_d)
497{
498 struct virtio_device *vdev =
499 container_of(_d, struct virtio_device, dev);
500 struct virtio_mmio_device *vm_dev =
501 container_of(vdev, struct virtio_mmio_device, vdev);
502 struct platform_device *pdev = vm_dev->pdev;
503
504 devm_kfree(&pdev->dev, vm_dev);
505}
506
507/* Platform device */
508
509static int virtio_mmio_probe(struct platform_device *pdev)
510{
511 struct virtio_mmio_device *vm_dev;
512 struct resource *mem;
513 unsigned long magic;
514 int rc;
515
516 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
517 if (!mem)
518 return -EINVAL;
519
520 if (!devm_request_mem_region(&pdev->dev, mem->start,
521 resource_size(mem), pdev->name))
522 return -EBUSY;
523
524 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
525 if (!vm_dev)
526 return -ENOMEM;
527
528 vm_dev->vdev.dev.parent = &pdev->dev;
529 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
530 vm_dev->vdev.config = &virtio_mmio_config_ops;
531 vm_dev->pdev = pdev;
532 INIT_LIST_HEAD(&vm_dev->virtqueues);
533 spin_lock_init(&vm_dev->lock);
534
535 vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
536 if (vm_dev->base == NULL)
537 return -EFAULT;
538
539 /* Check magic value */
540 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
541 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
542 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
543 return -ENODEV;
544 }
545
546 /* Check device version */
547 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
548 if (vm_dev->version < 1 || vm_dev->version > 2) {
549 dev_err(&pdev->dev, "Version %ld not supported!\n",
550 vm_dev->version);
551 return -ENXIO;
552 }
553
554 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
555 if (vm_dev->vdev.id.device == 0) {
556 /*
557 * virtio-mmio device with an ID 0 is a (dummy) placeholder
558 * with no function. End probing now with no error reported.
559 */
560 return -ENODEV;
561 }
562 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
563
564 if (vm_dev->version == 1) {
565 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
566
567 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
568 /*
569 * In the legacy case, ensure our coherently-allocated virtio
570 * ring will be at an address expressable as a 32-bit PFN.
571 */
572 if (!rc)
573 dma_set_coherent_mask(&pdev->dev,
574 DMA_BIT_MASK(32 + PAGE_SHIFT));
575 } else {
576 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
577 }
578 if (rc)
579 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
580 if (rc)
581 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
582
583 platform_set_drvdata(pdev, vm_dev);
584
585 rc = register_virtio_device(&vm_dev->vdev);
586 if (rc)
587 put_device(&vm_dev->vdev.dev);
588
589 return rc;
590}
591
592static int virtio_mmio_remove(struct platform_device *pdev)
593{
594 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
595 unregister_virtio_device(&vm_dev->vdev);
596
597 return 0;
598}
599
600
601
602/* Devices list parameter */
603
604#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
605
606static struct device vm_cmdline_parent = {
607 .init_name = "virtio-mmio-cmdline",
608};
609
610static int vm_cmdline_parent_registered;
611static int vm_cmdline_id;
612
613static int vm_cmdline_set(const char *device,
614 const struct kernel_param *kp)
615{
616 int err;
617 struct resource resources[2] = {};
618 char *str;
619 long long int base, size;
620 unsigned int irq;
621 int processed, consumed = 0;
622 struct platform_device *pdev;
623
624 /* Consume "size" part of the command line parameter */
625 size = memparse(device, &str);
626
627 /* Get "@<base>:<irq>[:<id>]" chunks */
628 processed = sscanf(str, "@%lli:%u%n:%d%n",
629 &base, &irq, &consumed,
630 &vm_cmdline_id, &consumed);
631
632 /*
633 * sscanf() must processes at least 2 chunks; also there
634 * must be no extra characters after the last chunk, so
635 * str[consumed] must be '\0'
636 */
637 if (processed < 2 || str[consumed])
638 return -EINVAL;
639
640 resources[0].flags = IORESOURCE_MEM;
641 resources[0].start = base;
642 resources[0].end = base + size - 1;
643
644 resources[1].flags = IORESOURCE_IRQ;
645 resources[1].start = resources[1].end = irq;
646
647 if (!vm_cmdline_parent_registered) {
648 err = device_register(&vm_cmdline_parent);
649 if (err) {
650 pr_err("Failed to register parent device!\n");
651 return err;
652 }
653 vm_cmdline_parent_registered = 1;
654 }
655
656 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
657 vm_cmdline_id,
658 (unsigned long long)resources[0].start,
659 (unsigned long long)resources[0].end,
660 (int)resources[1].start);
661
662 pdev = platform_device_register_resndata(&vm_cmdline_parent,
663 "virtio-mmio", vm_cmdline_id++,
664 resources, ARRAY_SIZE(resources), NULL, 0);
665
666 return PTR_ERR_OR_ZERO(pdev);
667}
668
669static int vm_cmdline_get_device(struct device *dev, void *data)
670{
671 char *buffer = data;
672 unsigned int len = strlen(buffer);
673 struct platform_device *pdev = to_platform_device(dev);
674
675 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
676 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
677 (unsigned long long)pdev->resource[0].start,
678 (unsigned long long)pdev->resource[1].start,
679 pdev->id);
680 return 0;
681}
682
683static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
684{
685 buffer[0] = '\0';
686 device_for_each_child(&vm_cmdline_parent, buffer,
687 vm_cmdline_get_device);
688 return strlen(buffer) + 1;
689}
690
691static const struct kernel_param_ops vm_cmdline_param_ops = {
692 .set = vm_cmdline_set,
693 .get = vm_cmdline_get,
694};
695
696device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
697
698static int vm_unregister_cmdline_device(struct device *dev,
699 void *data)
700{
701 platform_device_unregister(to_platform_device(dev));
702
703 return 0;
704}
705
706static void vm_unregister_cmdline_devices(void)
707{
708 if (vm_cmdline_parent_registered) {
709 device_for_each_child(&vm_cmdline_parent, NULL,
710 vm_unregister_cmdline_device);
711 device_unregister(&vm_cmdline_parent);
712 vm_cmdline_parent_registered = 0;
713 }
714}
715
716#else
717
718static void vm_unregister_cmdline_devices(void)
719{
720}
721
722#endif
723
724/* Platform driver */
725
726static const struct of_device_id virtio_mmio_match[] = {
727 { .compatible = "virtio,mmio", },
728 {},
729};
730MODULE_DEVICE_TABLE(of, virtio_mmio_match);
731
732#ifdef CONFIG_ACPI
733static const struct acpi_device_id virtio_mmio_acpi_match[] = {
734 { "LNRO0005", },
735 { }
736};
737MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
738#endif
739
740static struct platform_driver virtio_mmio_driver = {
741 .probe = virtio_mmio_probe,
742 .remove = virtio_mmio_remove,
743 .driver = {
744 .name = "virtio-mmio",
745 .of_match_table = virtio_mmio_match,
746 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
747 },
748};
749
750static int __init virtio_mmio_init(void)
751{
752 return platform_driver_register(&virtio_mmio_driver);
753}
754
755static void __exit virtio_mmio_exit(void)
756{
757 platform_driver_unregister(&virtio_mmio_driver);
758 vm_unregister_cmdline_devices();
759}
760
761module_init(virtio_mmio_init);
762module_exit(virtio_mmio_exit);
763
764MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
765MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
766MODULE_LICENSE("GPL");