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Merge tag 'ceph-for-4.13-rc8' of git://github.com/ceph/ceph-client
[linux/fpc-iii.git] / drivers / virtio / virtio_mmio.c
blob74dc7170fd351e02d1732357b0705f66c507f7ce
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
87 struct 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
99 struct 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
111 static 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
126 static 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
151 static 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
193 static 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
236 static 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
246 static 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
253 static 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
263 static 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 */
276 static 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. */
287 static 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
316 static 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
341 static 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
352 static 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
433 error_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);
441 error_kmalloc:
442 error_available:
443 return ERR_PTR(err);
444 }
445
446 static 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
474 static 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
481 static 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
496 static void virtio_mmio_release_dev_empty(struct device *_d) {}
497
498 /* Platform device */
499
500 static int virtio_mmio_probe(struct platform_device *pdev)
501 {
502 struct virtio_mmio_device *vm_dev;
503 struct resource *mem;
504 unsigned long magic;
505 int rc;
506
507 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
508 if (!mem)
509 return -EINVAL;
510
511 if (!devm_request_mem_region(&pdev->dev, mem->start,
512 resource_size(mem), pdev->name))
513 return -EBUSY;
514
515 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
516 if (!vm_dev)
517 return -ENOMEM;
518
519 vm_dev->vdev.dev.parent = &pdev->dev;
520 vm_dev->vdev.dev.release = virtio_mmio_release_dev_empty;
521 vm_dev->vdev.config = &virtio_mmio_config_ops;
522 vm_dev->pdev = pdev;
523 INIT_LIST_HEAD(&vm_dev->virtqueues);
524 spin_lock_init(&vm_dev->lock);
525
526 vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
527 if (vm_dev->base == NULL)
528 return -EFAULT;
529
530 /* Check magic value */
531 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
532 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
533 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
534 return -ENODEV;
535 }
536
537 /* Check device version */
538 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
539 if (vm_dev->version < 1 || vm_dev->version > 2) {
540 dev_err(&pdev->dev, "Version %ld not supported!\n",
541 vm_dev->version);
542 return -ENXIO;
543 }
544
545 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
546 if (vm_dev->vdev.id.device == 0) {
547 /*
548 * virtio-mmio device with an ID 0 is a (dummy) placeholder
549 * with no function. End probing now with no error reported.
550 */
551 return -ENODEV;
552 }
553 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
554
555 if (vm_dev->version == 1) {
556 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
557
558 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
559 /*
560 * In the legacy case, ensure our coherently-allocated virtio
561 * ring will be at an address expressable as a 32-bit PFN.
562 */
563 if (!rc)
564 dma_set_coherent_mask(&pdev->dev,
565 DMA_BIT_MASK(32 + PAGE_SHIFT));
566 } else {
567 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
568 }
569 if (rc)
570 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
571 if (rc)
572 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
573
574 platform_set_drvdata(pdev, vm_dev);
575
576 return register_virtio_device(&vm_dev->vdev);
577 }
578
579 static int virtio_mmio_remove(struct platform_device *pdev)
580 {
581 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
582
583 unregister_virtio_device(&vm_dev->vdev);
584
585 return 0;
586 }
587
588
589
590 /* Devices list parameter */
591
592 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
593
594 static struct device vm_cmdline_parent = {
595 .init_name = "virtio-mmio-cmdline",
596 };
597
598 static int vm_cmdline_parent_registered;
599 static int vm_cmdline_id;
600
601 static int vm_cmdline_set(const char *device,
602 const struct kernel_param *kp)
603 {
604 int err;
605 struct resource resources[2] = {};
606 char *str;
607 long long int base, size;
608 unsigned int irq;
609 int processed, consumed = 0;
610 struct platform_device *pdev;
611
612 /* Consume "size" part of the command line parameter */
613 size = memparse(device, &str);
614
615 /* Get "@<base>:<irq>[:<id>]" chunks */
616 processed = sscanf(str, "@%lli:%u%n:%d%n",
617 &base, &irq, &consumed,
618 &vm_cmdline_id, &consumed);
619
620 /*
621 * sscanf() must processes at least 2 chunks; also there
622 * must be no extra characters after the last chunk, so
623 * str[consumed] must be '\0'
624 */
625 if (processed < 2 || str[consumed])
626 return -EINVAL;
627
628 resources[0].flags = IORESOURCE_MEM;
629 resources[0].start = base;
630 resources[0].end = base + size - 1;
631
632 resources[1].flags = IORESOURCE_IRQ;
633 resources[1].start = resources[1].end = irq;
634
635 if (!vm_cmdline_parent_registered) {
636 err = device_register(&vm_cmdline_parent);
637 if (err) {
638 pr_err("Failed to register parent device!\n");
639 return err;
640 }
641 vm_cmdline_parent_registered = 1;
642 }
643
644 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
645 vm_cmdline_id,
646 (unsigned long long)resources[0].start,
647 (unsigned long long)resources[0].end,
648 (int)resources[1].start);
649
650 pdev = platform_device_register_resndata(&vm_cmdline_parent,
651 "virtio-mmio", vm_cmdline_id++,
652 resources, ARRAY_SIZE(resources), NULL, 0);
653 if (IS_ERR(pdev))
654 return PTR_ERR(pdev);
655
656 return 0;
657 }
658
659 static int vm_cmdline_get_device(struct device *dev, void *data)
660 {
661 char *buffer = data;
662 unsigned int len = strlen(buffer);
663 struct platform_device *pdev = to_platform_device(dev);
664
665 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
666 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
667 (unsigned long long)pdev->resource[0].start,
668 (unsigned long long)pdev->resource[1].start,
669 pdev->id);
670 return 0;
671 }
672
673 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
674 {
675 buffer[0] = '\0';
676 device_for_each_child(&vm_cmdline_parent, buffer,
677 vm_cmdline_get_device);
678 return strlen(buffer) + 1;
679 }
680
681 static const struct kernel_param_ops vm_cmdline_param_ops = {
682 .set = vm_cmdline_set,
683 .get = vm_cmdline_get,
684 };
685
686 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
687
688 static int vm_unregister_cmdline_device(struct device *dev,
689 void *data)
690 {
691 platform_device_unregister(to_platform_device(dev));
692
693 return 0;
694 }
695
696 static void vm_unregister_cmdline_devices(void)
697 {
698 if (vm_cmdline_parent_registered) {
699 device_for_each_child(&vm_cmdline_parent, NULL,
700 vm_unregister_cmdline_device);
701 device_unregister(&vm_cmdline_parent);
702 vm_cmdline_parent_registered = 0;
703 }
704 }
705
706 #else
707
708 static void vm_unregister_cmdline_devices(void)
709 {
710 }
711
712 #endif
713
714 /* Platform driver */
715
716 static struct of_device_id virtio_mmio_match[] = {
717 { .compatible = "virtio,mmio", },
718 {},
719 };
720 MODULE_DEVICE_TABLE(of, virtio_mmio_match);
721
722 #ifdef CONFIG_ACPI
723 static const struct acpi_device_id virtio_mmio_acpi_match[] = {
724 { "LNRO0005", },
725 { }
726 };
727 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
728 #endif
729
730 static struct platform_driver virtio_mmio_driver = {
731 .probe = virtio_mmio_probe,
732 .remove = virtio_mmio_remove,
733 .driver = {
734 .name = "virtio-mmio",
735 .of_match_table = virtio_mmio_match,
736 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
737 },
738 };
739
740 static int __init virtio_mmio_init(void)
741 {
742 return platform_driver_register(&virtio_mmio_driver);
743 }
744
745 static void __exit virtio_mmio_exit(void)
746 {
747 platform_driver_unregister(&virtio_mmio_driver);
748 vm_unregister_cmdline_devices();
749 }
750
751 module_init(virtio_mmio_init);
752 module_exit(virtio_mmio_exit);
753
754 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
755 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
756 MODULE_LICENSE("GPL");
Linux with added FPC-III support