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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/highmem.h>
63#include <linux/interrupt.h>
64#include <linux/io.h>
65#include <linux/list.h>
66#include <linux/module.h>
67#include <linux/platform_device.h>
68#include <linux/slab.h>
69#include <linux/spinlock.h>
70#include <linux/virtio.h>
71#include <linux/virtio_config.h>
72#include <linux/virtio_mmio.h>
73#include <linux/virtio_ring.h>
74
75
76
77/* The alignment to use between consumer and producer parts of vring.
78 * Currently hardcoded to the page size. */
79#define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
80
81
82
83#define to_virtio_mmio_device(_plat_dev) \
84 container_of(_plat_dev, struct virtio_mmio_device, vdev)
85
86struct virtio_mmio_device {
87 struct virtio_device vdev;
88 struct platform_device *pdev;
89
90 void __iomem *base;
91 unsigned long version;
92
93 /* a list of queues so we can dispatch IRQs */
94 spinlock_t lock;
95 struct list_head virtqueues;
96};
97
98struct virtio_mmio_vq_info {
99 /* the actual virtqueue */
100 struct virtqueue *vq;
101
102 /* the list node for the virtqueues list */
103 struct list_head node;
104};
105
106
107
108/* Configuration interface */
109
110static u64 vm_get_features(struct virtio_device *vdev)
111{
112 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
113 u64 features;
114
115 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
116 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
117 features <<= 32;
118
119 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
120 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
121
122 return features;
123}
124
125static int vm_finalize_features(struct virtio_device *vdev)
126{
127 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
128
129 /* Give virtio_ring a chance to accept features. */
130 vring_transport_features(vdev);
131
132 /* Make sure there is are no mixed devices */
133 if (vm_dev->version == 2 &&
134 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
135 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
136 return -EINVAL;
137 }
138
139 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
140 writel((u32)(vdev->features >> 32),
141 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
142
143 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
144 writel((u32)vdev->features,
145 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
146
147 return 0;
148}
149
150static void vm_get(struct virtio_device *vdev, unsigned offset,
151 void *buf, unsigned len)
152{
153 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
154 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
155 u8 b;
156 __le16 w;
157 __le32 l;
158
159 if (vm_dev->version == 1) {
160 u8 *ptr = buf;
161 int i;
162
163 for (i = 0; i < len; i++)
164 ptr[i] = readb(base + offset + i);
165 return;
166 }
167
168 switch (len) {
169 case 1:
170 b = readb(base + offset);
171 memcpy(buf, &b, sizeof b);
172 break;
173 case 2:
174 w = cpu_to_le16(readw(base + offset));
175 memcpy(buf, &w, sizeof w);
176 break;
177 case 4:
178 l = cpu_to_le32(readl(base + offset));
179 memcpy(buf, &l, sizeof l);
180 break;
181 case 8:
182 l = cpu_to_le32(readl(base + offset));
183 memcpy(buf, &l, sizeof l);
184 l = cpu_to_le32(ioread32(base + offset + sizeof l));
185 memcpy(buf + sizeof l, &l, sizeof l);
186 break;
187 default:
188 BUG();
189 }
190}
191
192static void vm_set(struct virtio_device *vdev, unsigned offset,
193 const void *buf, unsigned len)
194{
195 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
196 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
197 u8 b;
198 __le16 w;
199 __le32 l;
200
201 if (vm_dev->version == 1) {
202 const u8 *ptr = buf;
203 int i;
204
205 for (i = 0; i < len; i++)
206 writeb(ptr[i], base + offset + i);
207
208 return;
209 }
210
211 switch (len) {
212 case 1:
213 memcpy(&b, buf, sizeof b);
214 writeb(b, base + offset);
215 break;
216 case 2:
217 memcpy(&w, buf, sizeof w);
218 writew(le16_to_cpu(w), base + offset);
219 break;
220 case 4:
221 memcpy(&l, buf, sizeof l);
222 writel(le32_to_cpu(l), base + offset);
223 break;
224 case 8:
225 memcpy(&l, buf, sizeof l);
226 writel(le32_to_cpu(l), base + offset);
227 memcpy(&l, buf + sizeof l, sizeof l);
228 writel(le32_to_cpu(l), base + offset + sizeof l);
229 break;
230 default:
231 BUG();
232 }
233}
234
235static u32 vm_generation(struct virtio_device *vdev)
236{
237 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
238
239 if (vm_dev->version == 1)
240 return 0;
241 else
242 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
243}
244
245static u8 vm_get_status(struct virtio_device *vdev)
246{
247 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
248
249 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
250}
251
252static void vm_set_status(struct virtio_device *vdev, u8 status)
253{
254 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
255
256 /* We should never be setting status to 0. */
257 BUG_ON(status == 0);
258
259 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
260}
261
262static void vm_reset(struct virtio_device *vdev)
263{
264 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
265
266 /* 0 status means a reset. */
267 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
268}
269
270
271
272/* Transport interface */
273
274/* the notify function used when creating a virt queue */
275static bool vm_notify(struct virtqueue *vq)
276{
277 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
278
279 /* We write the queue's selector into the notification register to
280 * signal the other end */
281 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
282 return true;
283}
284
285/* Notify all virtqueues on an interrupt. */
286static irqreturn_t vm_interrupt(int irq, void *opaque)
287{
288 struct virtio_mmio_device *vm_dev = opaque;
289 struct virtio_mmio_vq_info *info;
290 unsigned long status;
291 unsigned long flags;
292 irqreturn_t ret = IRQ_NONE;
293
294 /* Read and acknowledge interrupts */
295 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
296 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
297
298 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
299 virtio_config_changed(&vm_dev->vdev);
300 ret = IRQ_HANDLED;
301 }
302
303 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
304 spin_lock_irqsave(&vm_dev->lock, flags);
305 list_for_each_entry(info, &vm_dev->virtqueues, node)
306 ret |= vring_interrupt(irq, info->vq);
307 spin_unlock_irqrestore(&vm_dev->lock, flags);
308 }
309
310 return ret;
311}
312
313
314
315static void vm_del_vq(struct virtqueue *vq)
316{
317 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
318 struct virtio_mmio_vq_info *info = vq->priv;
319 unsigned long flags;
320 unsigned int index = vq->index;
321
322 spin_lock_irqsave(&vm_dev->lock, flags);
323 list_del(&info->node);
324 spin_unlock_irqrestore(&vm_dev->lock, flags);
325
326 /* Select and deactivate the queue */
327 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
328 if (vm_dev->version == 1) {
329 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
330 } else {
331 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
332 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
333 }
334
335 vring_del_virtqueue(vq);
336
337 kfree(info);
338}
339
340static void vm_del_vqs(struct virtio_device *vdev)
341{
342 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
343 struct virtqueue *vq, *n;
344
345 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
346 vm_del_vq(vq);
347
348 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
349}
350
351static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
352 void (*callback)(struct virtqueue *vq),
353 const char *name)
354{
355 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
356 struct virtio_mmio_vq_info *info;
357 struct virtqueue *vq;
358 unsigned long flags;
359 unsigned int num;
360 int err;
361
362 if (!name)
363 return NULL;
364
365 /* Select the queue we're interested in */
366 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
367
368 /* Queue shouldn't already be set up. */
369 if (readl(vm_dev->base + (vm_dev->version == 1 ?
370 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
371 err = -ENOENT;
372 goto error_available;
373 }
374
375 /* Allocate and fill out our active queue description */
376 info = kmalloc(sizeof(*info), GFP_KERNEL);
377 if (!info) {
378 err = -ENOMEM;
379 goto error_kmalloc;
380 }
381
382 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
383 if (num == 0) {
384 err = -ENOENT;
385 goto error_new_virtqueue;
386 }
387
388 /* Create the vring */
389 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
390 true, true, vm_notify, callback, name);
391 if (!vq) {
392 err = -ENOMEM;
393 goto error_new_virtqueue;
394 }
395
396 /* Activate the queue */
397 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
398 if (vm_dev->version == 1) {
399 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
400 writel(virtqueue_get_desc_addr(vq) >> PAGE_SHIFT,
401 vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
402 } else {
403 u64 addr;
404
405 addr = virtqueue_get_desc_addr(vq);
406 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
407 writel((u32)(addr >> 32),
408 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
409
410 addr = virtqueue_get_avail_addr(vq);
411 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
412 writel((u32)(addr >> 32),
413 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
414
415 addr = virtqueue_get_used_addr(vq);
416 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
417 writel((u32)(addr >> 32),
418 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
419
420 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
421 }
422
423 vq->priv = info;
424 info->vq = vq;
425
426 spin_lock_irqsave(&vm_dev->lock, flags);
427 list_add(&info->node, &vm_dev->virtqueues);
428 spin_unlock_irqrestore(&vm_dev->lock, flags);
429
430 return vq;
431
432error_new_virtqueue:
433 if (vm_dev->version == 1) {
434 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
435 } else {
436 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
437 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
438 }
439 kfree(info);
440error_kmalloc:
441error_available:
442 return ERR_PTR(err);
443}
444
445static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
446 struct virtqueue *vqs[],
447 vq_callback_t *callbacks[],
448 const char * const names[])
449{
450 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
451 unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
452 int i, err;
453
454 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
455 dev_name(&vdev->dev), vm_dev);
456 if (err)
457 return err;
458
459 for (i = 0; i < nvqs; ++i) {
460 vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i]);
461 if (IS_ERR(vqs[i])) {
462 vm_del_vqs(vdev);
463 return PTR_ERR(vqs[i]);
464 }
465 }
466
467 return 0;
468}
469
470static const char *vm_bus_name(struct virtio_device *vdev)
471{
472 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
473
474 return vm_dev->pdev->name;
475}
476
477static const struct virtio_config_ops virtio_mmio_config_ops = {
478 .get = vm_get,
479 .set = vm_set,
480 .generation = vm_generation,
481 .get_status = vm_get_status,
482 .set_status = vm_set_status,
483 .reset = vm_reset,
484 .find_vqs = vm_find_vqs,
485 .del_vqs = vm_del_vqs,
486 .get_features = vm_get_features,
487 .finalize_features = vm_finalize_features,
488 .bus_name = vm_bus_name,
489};
490
491
492
493/* Platform device */
494
495static int virtio_mmio_probe(struct platform_device *pdev)
496{
497 struct virtio_mmio_device *vm_dev;
498 struct resource *mem;
499 unsigned long magic;
500
501 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
502 if (!mem)
503 return -EINVAL;
504
505 if (!devm_request_mem_region(&pdev->dev, mem->start,
506 resource_size(mem), pdev->name))
507 return -EBUSY;
508
509 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
510 if (!vm_dev)
511 return -ENOMEM;
512
513 vm_dev->vdev.dev.parent = &pdev->dev;
514 vm_dev->vdev.config = &virtio_mmio_config_ops;
515 vm_dev->pdev = pdev;
516 INIT_LIST_HEAD(&vm_dev->virtqueues);
517 spin_lock_init(&vm_dev->lock);
518
519 vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
520 if (vm_dev->base == NULL)
521 return -EFAULT;
522
523 /* Check magic value */
524 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
525 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
526 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
527 return -ENODEV;
528 }
529
530 /* Check device version */
531 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
532 if (vm_dev->version < 1 || vm_dev->version > 2) {
533 dev_err(&pdev->dev, "Version %ld not supported!\n",
534 vm_dev->version);
535 return -ENXIO;
536 }
537
538 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
539 if (vm_dev->vdev.id.device == 0) {
540 /*
541 * virtio-mmio device with an ID 0 is a (dummy) placeholder
542 * with no function. End probing now with no error reported.
543 */
544 return -ENODEV;
545 }
546 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
547
548 if (vm_dev->version == 1)
549 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
550
551 platform_set_drvdata(pdev, vm_dev);
552
553 return register_virtio_device(&vm_dev->vdev);
554}
555
556static int virtio_mmio_remove(struct platform_device *pdev)
557{
558 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
559
560 unregister_virtio_device(&vm_dev->vdev);
561
562 return 0;
563}
564
565
566
567/* Devices list parameter */
568
569#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
570
571static struct device vm_cmdline_parent = {
572 .init_name = "virtio-mmio-cmdline",
573};
574
575static int vm_cmdline_parent_registered;
576static int vm_cmdline_id;
577
578static int vm_cmdline_set(const char *device,
579 const struct kernel_param *kp)
580{
581 int err;
582 struct resource resources[2] = {};
583 char *str;
584 long long int base, size;
585 unsigned int irq;
586 int processed, consumed = 0;
587 struct platform_device *pdev;
588
589 /* Consume "size" part of the command line parameter */
590 size = memparse(device, &str);
591
592 /* Get "@<base>:<irq>[:<id>]" chunks */
593 processed = sscanf(str, "@%lli:%u%n:%d%n",
594 &base, &irq, &consumed,
595 &vm_cmdline_id, &consumed);
596
597 /*
598 * sscanf() must processes at least 2 chunks; also there
599 * must be no extra characters after the last chunk, so
600 * str[consumed] must be '\0'
601 */
602 if (processed < 2 || str[consumed])
603 return -EINVAL;
604
605 resources[0].flags = IORESOURCE_MEM;
606 resources[0].start = base;
607 resources[0].end = base + size - 1;
608
609 resources[1].flags = IORESOURCE_IRQ;
610 resources[1].start = resources[1].end = irq;
611
612 if (!vm_cmdline_parent_registered) {
613 err = device_register(&vm_cmdline_parent);
614 if (err) {
615 pr_err("Failed to register parent device!\n");
616 return err;
617 }
618 vm_cmdline_parent_registered = 1;
619 }
620
621 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
622 vm_cmdline_id,
623 (unsigned long long)resources[0].start,
624 (unsigned long long)resources[0].end,
625 (int)resources[1].start);
626
627 pdev = platform_device_register_resndata(&vm_cmdline_parent,
628 "virtio-mmio", vm_cmdline_id++,
629 resources, ARRAY_SIZE(resources), NULL, 0);
630 if (IS_ERR(pdev))
631 return PTR_ERR(pdev);
632
633 return 0;
634}
635
636static int vm_cmdline_get_device(struct device *dev, void *data)
637{
638 char *buffer = data;
639 unsigned int len = strlen(buffer);
640 struct platform_device *pdev = to_platform_device(dev);
641
642 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
643 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
644 (unsigned long long)pdev->resource[0].start,
645 (unsigned long long)pdev->resource[1].start,
646 pdev->id);
647 return 0;
648}
649
650static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
651{
652 buffer[0] = '\0';
653 device_for_each_child(&vm_cmdline_parent, buffer,
654 vm_cmdline_get_device);
655 return strlen(buffer) + 1;
656}
657
658static const struct kernel_param_ops vm_cmdline_param_ops = {
659 .set = vm_cmdline_set,
660 .get = vm_cmdline_get,
661};
662
663device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
664
665static int vm_unregister_cmdline_device(struct device *dev,
666 void *data)
667{
668 platform_device_unregister(to_platform_device(dev));
669
670 return 0;
671}
672
673static void vm_unregister_cmdline_devices(void)
674{
675 if (vm_cmdline_parent_registered) {
676 device_for_each_child(&vm_cmdline_parent, NULL,
677 vm_unregister_cmdline_device);
678 device_unregister(&vm_cmdline_parent);
679 vm_cmdline_parent_registered = 0;
680 }
681}
682
683#else
684
685static void vm_unregister_cmdline_devices(void)
686{
687}
688
689#endif
690
691/* Platform driver */
692
693static struct of_device_id virtio_mmio_match[] = {
694 { .compatible = "virtio,mmio", },
695 {},
696};
697MODULE_DEVICE_TABLE(of, virtio_mmio_match);
698
699#ifdef CONFIG_ACPI
700static const struct acpi_device_id virtio_mmio_acpi_match[] = {
701 { "LNRO0005", },
702 { }
703};
704MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
705#endif
706
707static struct platform_driver virtio_mmio_driver = {
708 .probe = virtio_mmio_probe,
709 .remove = virtio_mmio_remove,
710 .driver = {
711 .name = "virtio-mmio",
712 .of_match_table = virtio_mmio_match,
713 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
714 },
715};
716
717static int __init virtio_mmio_init(void)
718{
719 return platform_driver_register(&virtio_mmio_driver);
720}
721
722static void __exit virtio_mmio_exit(void)
723{
724 platform_driver_unregister(&virtio_mmio_driver);
725 vm_unregister_cmdline_devices();
726}
727
728module_init(virtio_mmio_init);
729module_exit(virtio_mmio_exit);
730
731MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
732MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
733MODULE_LICENSE("GPL");
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/pm.h>
66#include <linux/slab.h>
67#include <linux/spinlock.h>
68#include <linux/virtio.h>
69#include <linux/virtio_config.h>
70#include <uapi/linux/virtio_mmio.h>
71#include <linux/virtio_ring.h>
72
73
74
75/* The alignment to use between consumer and producer parts of vring.
76 * Currently hardcoded to the page size. */
77#define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
78
79
80
81#define to_virtio_mmio_device(_plat_dev) \
82 container_of(_plat_dev, struct virtio_mmio_device, vdev)
83
84struct virtio_mmio_device {
85 struct virtio_device vdev;
86 struct platform_device *pdev;
87
88 void __iomem *base;
89 unsigned long version;
90
91 /* a list of queues so we can dispatch IRQs */
92 spinlock_t lock;
93 struct list_head virtqueues;
94};
95
96struct virtio_mmio_vq_info {
97 /* the actual virtqueue */
98 struct virtqueue *vq;
99
100 /* the list node for the virtqueues list */
101 struct list_head node;
102};
103
104
105
106/* Configuration interface */
107
108static u64 vm_get_features(struct virtio_device *vdev)
109{
110 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
111 u64 features;
112
113 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
114 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
115 features <<= 32;
116
117 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
118 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
119
120 return features;
121}
122
123static int vm_finalize_features(struct virtio_device *vdev)
124{
125 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
126
127 /* Give virtio_ring a chance to accept features. */
128 vring_transport_features(vdev);
129
130 /* Make sure there are no mixed devices */
131 if (vm_dev->version == 2 &&
132 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
133 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
134 return -EINVAL;
135 }
136
137 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
138 writel((u32)(vdev->features >> 32),
139 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
140
141 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
142 writel((u32)vdev->features,
143 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
144
145 return 0;
146}
147
148static void vm_get(struct virtio_device *vdev, unsigned int offset,
149 void *buf, unsigned int len)
150{
151 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
152 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
153 u8 b;
154 __le16 w;
155 __le32 l;
156
157 if (vm_dev->version == 1) {
158 u8 *ptr = buf;
159 int i;
160
161 for (i = 0; i < len; i++)
162 ptr[i] = readb(base + offset + i);
163 return;
164 }
165
166 switch (len) {
167 case 1:
168 b = readb(base + offset);
169 memcpy(buf, &b, sizeof b);
170 break;
171 case 2:
172 w = cpu_to_le16(readw(base + offset));
173 memcpy(buf, &w, sizeof w);
174 break;
175 case 4:
176 l = cpu_to_le32(readl(base + offset));
177 memcpy(buf, &l, sizeof l);
178 break;
179 case 8:
180 l = cpu_to_le32(readl(base + offset));
181 memcpy(buf, &l, sizeof l);
182 l = cpu_to_le32(ioread32(base + offset + sizeof l));
183 memcpy(buf + sizeof l, &l, sizeof l);
184 break;
185 default:
186 BUG();
187 }
188}
189
190static void vm_set(struct virtio_device *vdev, unsigned int offset,
191 const void *buf, unsigned int len)
192{
193 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
194 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
195 u8 b;
196 __le16 w;
197 __le32 l;
198
199 if (vm_dev->version == 1) {
200 const u8 *ptr = buf;
201 int i;
202
203 for (i = 0; i < len; i++)
204 writeb(ptr[i], base + offset + i);
205
206 return;
207 }
208
209 switch (len) {
210 case 1:
211 memcpy(&b, buf, sizeof b);
212 writeb(b, base + offset);
213 break;
214 case 2:
215 memcpy(&w, buf, sizeof w);
216 writew(le16_to_cpu(w), base + offset);
217 break;
218 case 4:
219 memcpy(&l, buf, sizeof l);
220 writel(le32_to_cpu(l), base + offset);
221 break;
222 case 8:
223 memcpy(&l, buf, sizeof l);
224 writel(le32_to_cpu(l), base + offset);
225 memcpy(&l, buf + sizeof l, sizeof l);
226 writel(le32_to_cpu(l), base + offset + sizeof l);
227 break;
228 default:
229 BUG();
230 }
231}
232
233static u32 vm_generation(struct virtio_device *vdev)
234{
235 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
236
237 if (vm_dev->version == 1)
238 return 0;
239 else
240 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
241}
242
243static u8 vm_get_status(struct virtio_device *vdev)
244{
245 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
246
247 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
248}
249
250static void vm_set_status(struct virtio_device *vdev, u8 status)
251{
252 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
253
254 /* We should never be setting status to 0. */
255 BUG_ON(status == 0);
256
257 /*
258 * Per memory-barriers.txt, wmb() is not needed to guarantee
259 * that the cache coherent memory writes have completed
260 * before writing to the MMIO region.
261 */
262 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
263}
264
265static void vm_reset(struct virtio_device *vdev)
266{
267 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
268
269 /* 0 status means a reset. */
270 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
271}
272
273
274
275/* Transport interface */
276
277/* the notify function used when creating a virt queue */
278static bool vm_notify(struct virtqueue *vq)
279{
280 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
281
282 /* We write the queue's selector into the notification register to
283 * signal the other end */
284 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
285 return true;
286}
287
288/* Notify all virtqueues on an interrupt. */
289static irqreturn_t vm_interrupt(int irq, void *opaque)
290{
291 struct virtio_mmio_device *vm_dev = opaque;
292 struct virtio_mmio_vq_info *info;
293 unsigned long status;
294 unsigned long flags;
295 irqreturn_t ret = IRQ_NONE;
296
297 /* Read and acknowledge interrupts */
298 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
299 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
300
301 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
302 virtio_config_changed(&vm_dev->vdev);
303 ret = IRQ_HANDLED;
304 }
305
306 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
307 spin_lock_irqsave(&vm_dev->lock, flags);
308 list_for_each_entry(info, &vm_dev->virtqueues, node)
309 ret |= vring_interrupt(irq, info->vq);
310 spin_unlock_irqrestore(&vm_dev->lock, flags);
311 }
312
313 return ret;
314}
315
316
317
318static void vm_del_vq(struct virtqueue *vq)
319{
320 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
321 struct virtio_mmio_vq_info *info = vq->priv;
322 unsigned long flags;
323 unsigned int index = vq->index;
324
325 spin_lock_irqsave(&vm_dev->lock, flags);
326 list_del(&info->node);
327 spin_unlock_irqrestore(&vm_dev->lock, flags);
328
329 /* Select and deactivate the queue */
330 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
331 if (vm_dev->version == 1) {
332 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
333 } else {
334 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
335 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
336 }
337
338 vring_del_virtqueue(vq);
339
340 kfree(info);
341}
342
343static void vm_del_vqs(struct virtio_device *vdev)
344{
345 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
346 struct virtqueue *vq, *n;
347
348 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
349 vm_del_vq(vq);
350
351 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
352}
353
354static void vm_synchronize_cbs(struct virtio_device *vdev)
355{
356 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
357
358 synchronize_irq(platform_get_irq(vm_dev->pdev, 0));
359}
360
361static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index,
362 void (*callback)(struct virtqueue *vq),
363 const char *name, bool ctx)
364{
365 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
366 struct virtio_mmio_vq_info *info;
367 struct virtqueue *vq;
368 unsigned long flags;
369 unsigned int num;
370 int err;
371
372 if (!name)
373 return NULL;
374
375 /* Select the queue we're interested in */
376 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
377
378 /* Queue shouldn't already be set up. */
379 if (readl(vm_dev->base + (vm_dev->version == 1 ?
380 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
381 err = -ENOENT;
382 goto error_available;
383 }
384
385 /* Allocate and fill out our active queue description */
386 info = kmalloc(sizeof(*info), GFP_KERNEL);
387 if (!info) {
388 err = -ENOMEM;
389 goto error_kmalloc;
390 }
391
392 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
393 if (num == 0) {
394 err = -ENOENT;
395 goto error_new_virtqueue;
396 }
397
398 /* Create the vring */
399 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
400 true, true, ctx, vm_notify, callback, name);
401 if (!vq) {
402 err = -ENOMEM;
403 goto error_new_virtqueue;
404 }
405
406 vq->num_max = num;
407
408 /* Activate the queue */
409 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
410 if (vm_dev->version == 1) {
411 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
412
413 /*
414 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
415 * that doesn't fit in 32bit, fail the setup rather than
416 * pretending to be successful.
417 */
418 if (q_pfn >> 32) {
419 dev_err(&vdev->dev,
420 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
421 0x1ULL << (32 + PAGE_SHIFT - 30));
422 err = -E2BIG;
423 goto error_bad_pfn;
424 }
425
426 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
427 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
428 } else {
429 u64 addr;
430
431 addr = virtqueue_get_desc_addr(vq);
432 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
433 writel((u32)(addr >> 32),
434 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
435
436 addr = virtqueue_get_avail_addr(vq);
437 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
438 writel((u32)(addr >> 32),
439 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
440
441 addr = virtqueue_get_used_addr(vq);
442 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
443 writel((u32)(addr >> 32),
444 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
445
446 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
447 }
448
449 vq->priv = info;
450 info->vq = vq;
451
452 spin_lock_irqsave(&vm_dev->lock, flags);
453 list_add(&info->node, &vm_dev->virtqueues);
454 spin_unlock_irqrestore(&vm_dev->lock, flags);
455
456 return vq;
457
458error_bad_pfn:
459 vring_del_virtqueue(vq);
460error_new_virtqueue:
461 if (vm_dev->version == 1) {
462 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
463 } else {
464 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
465 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
466 }
467 kfree(info);
468error_kmalloc:
469error_available:
470 return ERR_PTR(err);
471}
472
473static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
474 struct virtqueue *vqs[],
475 vq_callback_t *callbacks[],
476 const char * const names[],
477 const bool *ctx,
478 struct irq_affinity *desc)
479{
480 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
481 int irq = platform_get_irq(vm_dev->pdev, 0);
482 int i, err, queue_idx = 0;
483
484 if (irq < 0)
485 return irq;
486
487 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
488 dev_name(&vdev->dev), vm_dev);
489 if (err)
490 return err;
491
492 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source"))
493 enable_irq_wake(irq);
494
495 for (i = 0; i < nvqs; ++i) {
496 if (!names[i]) {
497 vqs[i] = NULL;
498 continue;
499 }
500
501 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
502 ctx ? ctx[i] : false);
503 if (IS_ERR(vqs[i])) {
504 vm_del_vqs(vdev);
505 return PTR_ERR(vqs[i]);
506 }
507 }
508
509 return 0;
510}
511
512static const char *vm_bus_name(struct virtio_device *vdev)
513{
514 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
515
516 return vm_dev->pdev->name;
517}
518
519static bool vm_get_shm_region(struct virtio_device *vdev,
520 struct virtio_shm_region *region, u8 id)
521{
522 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
523 u64 len, addr;
524
525 /* Select the region we're interested in */
526 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
527
528 /* Read the region size */
529 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
530 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
531
532 region->len = len;
533
534 /* Check if region length is -1. If that's the case, the shared memory
535 * region does not exist and there is no need to proceed further.
536 */
537 if (len == ~(u64)0)
538 return false;
539
540 /* Read the region base address */
541 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
542 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
543
544 region->addr = addr;
545
546 return true;
547}
548
549static const struct virtio_config_ops virtio_mmio_config_ops = {
550 .get = vm_get,
551 .set = vm_set,
552 .generation = vm_generation,
553 .get_status = vm_get_status,
554 .set_status = vm_set_status,
555 .reset = vm_reset,
556 .find_vqs = vm_find_vqs,
557 .del_vqs = vm_del_vqs,
558 .get_features = vm_get_features,
559 .finalize_features = vm_finalize_features,
560 .bus_name = vm_bus_name,
561 .get_shm_region = vm_get_shm_region,
562 .synchronize_cbs = vm_synchronize_cbs,
563};
564
565#ifdef CONFIG_PM_SLEEP
566static int virtio_mmio_freeze(struct device *dev)
567{
568 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
569
570 return virtio_device_freeze(&vm_dev->vdev);
571}
572
573static int virtio_mmio_restore(struct device *dev)
574{
575 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
576
577 if (vm_dev->version == 1)
578 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
579
580 return virtio_device_restore(&vm_dev->vdev);
581}
582
583static const struct dev_pm_ops virtio_mmio_pm_ops = {
584 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore)
585};
586#endif
587
588static void virtio_mmio_release_dev(struct device *_d)
589{
590 struct virtio_device *vdev =
591 container_of(_d, struct virtio_device, dev);
592 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
593 struct platform_device *pdev = vm_dev->pdev;
594
595 devm_kfree(&pdev->dev, vm_dev);
596}
597
598/* Platform device */
599
600static int virtio_mmio_probe(struct platform_device *pdev)
601{
602 struct virtio_mmio_device *vm_dev;
603 unsigned long magic;
604 int rc;
605
606 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
607 if (!vm_dev)
608 return -ENOMEM;
609
610 vm_dev->vdev.dev.parent = &pdev->dev;
611 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
612 vm_dev->vdev.config = &virtio_mmio_config_ops;
613 vm_dev->pdev = pdev;
614 INIT_LIST_HEAD(&vm_dev->virtqueues);
615 spin_lock_init(&vm_dev->lock);
616
617 vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
618 if (IS_ERR(vm_dev->base))
619 return PTR_ERR(vm_dev->base);
620
621 /* Check magic value */
622 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
623 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
624 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
625 return -ENODEV;
626 }
627
628 /* Check device version */
629 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
630 if (vm_dev->version < 1 || vm_dev->version > 2) {
631 dev_err(&pdev->dev, "Version %ld not supported!\n",
632 vm_dev->version);
633 return -ENXIO;
634 }
635
636 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
637 if (vm_dev->vdev.id.device == 0) {
638 /*
639 * virtio-mmio device with an ID 0 is a (dummy) placeholder
640 * with no function. End probing now with no error reported.
641 */
642 return -ENODEV;
643 }
644 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
645
646 if (vm_dev->version == 1) {
647 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
648
649 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
650 /*
651 * In the legacy case, ensure our coherently-allocated virtio
652 * ring will be at an address expressable as a 32-bit PFN.
653 */
654 if (!rc)
655 dma_set_coherent_mask(&pdev->dev,
656 DMA_BIT_MASK(32 + PAGE_SHIFT));
657 } else {
658 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
659 }
660 if (rc)
661 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
662 if (rc)
663 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
664
665 platform_set_drvdata(pdev, vm_dev);
666
667 rc = register_virtio_device(&vm_dev->vdev);
668 if (rc)
669 put_device(&vm_dev->vdev.dev);
670
671 return rc;
672}
673
674static int virtio_mmio_remove(struct platform_device *pdev)
675{
676 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
677 unregister_virtio_device(&vm_dev->vdev);
678
679 return 0;
680}
681
682
683
684/* Devices list parameter */
685
686#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
687
688static struct device vm_cmdline_parent = {
689 .init_name = "virtio-mmio-cmdline",
690};
691
692static int vm_cmdline_parent_registered;
693static int vm_cmdline_id;
694
695static int vm_cmdline_set(const char *device,
696 const struct kernel_param *kp)
697{
698 int err;
699 struct resource resources[2] = {};
700 char *str;
701 long long base, size;
702 unsigned int irq;
703 int processed, consumed = 0;
704 struct platform_device *pdev;
705
706 /* Consume "size" part of the command line parameter */
707 size = memparse(device, &str);
708
709 /* Get "@<base>:<irq>[:<id>]" chunks */
710 processed = sscanf(str, "@%lli:%u%n:%d%n",
711 &base, &irq, &consumed,
712 &vm_cmdline_id, &consumed);
713
714 /*
715 * sscanf() must process at least 2 chunks; also there
716 * must be no extra characters after the last chunk, so
717 * str[consumed] must be '\0'
718 */
719 if (processed < 2 || str[consumed] || irq == 0)
720 return -EINVAL;
721
722 resources[0].flags = IORESOURCE_MEM;
723 resources[0].start = base;
724 resources[0].end = base + size - 1;
725
726 resources[1].flags = IORESOURCE_IRQ;
727 resources[1].start = resources[1].end = irq;
728
729 if (!vm_cmdline_parent_registered) {
730 err = device_register(&vm_cmdline_parent);
731 if (err) {
732 put_device(&vm_cmdline_parent);
733 pr_err("Failed to register parent device!\n");
734 return err;
735 }
736 vm_cmdline_parent_registered = 1;
737 }
738
739 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
740 vm_cmdline_id,
741 (unsigned long long)resources[0].start,
742 (unsigned long long)resources[0].end,
743 (int)resources[1].start);
744
745 pdev = platform_device_register_resndata(&vm_cmdline_parent,
746 "virtio-mmio", vm_cmdline_id++,
747 resources, ARRAY_SIZE(resources), NULL, 0);
748
749 return PTR_ERR_OR_ZERO(pdev);
750}
751
752static int vm_cmdline_get_device(struct device *dev, void *data)
753{
754 char *buffer = data;
755 unsigned int len = strlen(buffer);
756 struct platform_device *pdev = to_platform_device(dev);
757
758 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
759 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
760 (unsigned long long)pdev->resource[0].start,
761 (unsigned long long)pdev->resource[1].start,
762 pdev->id);
763 return 0;
764}
765
766static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
767{
768 buffer[0] = '\0';
769 device_for_each_child(&vm_cmdline_parent, buffer,
770 vm_cmdline_get_device);
771 return strlen(buffer) + 1;
772}
773
774static const struct kernel_param_ops vm_cmdline_param_ops = {
775 .set = vm_cmdline_set,
776 .get = vm_cmdline_get,
777};
778
779device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
780
781static int vm_unregister_cmdline_device(struct device *dev,
782 void *data)
783{
784 platform_device_unregister(to_platform_device(dev));
785
786 return 0;
787}
788
789static void vm_unregister_cmdline_devices(void)
790{
791 if (vm_cmdline_parent_registered) {
792 device_for_each_child(&vm_cmdline_parent, NULL,
793 vm_unregister_cmdline_device);
794 device_unregister(&vm_cmdline_parent);
795 vm_cmdline_parent_registered = 0;
796 }
797}
798
799#else
800
801static void vm_unregister_cmdline_devices(void)
802{
803}
804
805#endif
806
807/* Platform driver */
808
809static const struct of_device_id virtio_mmio_match[] = {
810 { .compatible = "virtio,mmio", },
811 {},
812};
813MODULE_DEVICE_TABLE(of, virtio_mmio_match);
814
815#ifdef CONFIG_ACPI
816static const struct acpi_device_id virtio_mmio_acpi_match[] = {
817 { "LNRO0005", },
818 { }
819};
820MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
821#endif
822
823static struct platform_driver virtio_mmio_driver = {
824 .probe = virtio_mmio_probe,
825 .remove = virtio_mmio_remove,
826 .driver = {
827 .name = "virtio-mmio",
828 .of_match_table = virtio_mmio_match,
829 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
830#ifdef CONFIG_PM_SLEEP
831 .pm = &virtio_mmio_pm_ops,
832#endif
833 },
834};
835
836static int __init virtio_mmio_init(void)
837{
838 return platform_driver_register(&virtio_mmio_driver);
839}
840
841static void __exit virtio_mmio_exit(void)
842{
843 platform_driver_unregister(&virtio_mmio_driver);
844 vm_unregister_cmdline_devices();
845}
846
847module_init(virtio_mmio_init);
848module_exit(virtio_mmio_exit);
849
850MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
851MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
852MODULE_LICENSE("GPL");