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
83 struct 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
95 struct 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
vm_get_features(struct virtio_device * vdev)107 static 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
vm_finalize_features(struct virtio_device * vdev)122 static 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 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
vm_get(struct virtio_device * vdev,unsigned offset,void * buf,unsigned len)147 static 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
vm_set(struct virtio_device * vdev,unsigned offset,const void * buf,unsigned len)189 static 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
vm_generation(struct virtio_device * vdev)232 static 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
vm_get_status(struct virtio_device * vdev)242 static 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
vm_set_status(struct virtio_device * vdev,u8 status)249 static 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
vm_reset(struct virtio_device * vdev)259 static 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 */
vm_notify(struct virtqueue * vq)272 static 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. */
vm_interrupt(int irq,void * opaque)283 static 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
vm_del_vq(struct virtqueue * vq)312 static 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
vm_del_vqs(struct virtio_device * vdev)337 static 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
vm_setup_vq(struct virtio_device * vdev,unsigned index,void (* callback)(struct virtqueue * vq),const char * name,bool ctx)348 static 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
443 error_bad_pfn:
444 vring_del_virtqueue(vq);
445 error_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);
453 error_kmalloc:
454 error_available:
455 return ERR_PTR(err);
456 }
457
vm_find_vqs(struct virtio_device * vdev,unsigned nvqs,struct virtqueue * vqs[],vq_callback_t * callbacks[],const char * const names[],const bool * ctx,struct irq_affinity * desc)458 static 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
vm_bus_name(struct virtio_device * vdev)494 static 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
vm_get_shm_region(struct virtio_device * vdev,struct virtio_shm_region * region,u8 id)501 static bool vm_get_shm_region(struct virtio_device *vdev,
502 struct virtio_shm_region *region, u8 id)
503 {
504 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
505 u64 len, addr;
506
507 /* Select the region we're interested in */
508 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
509
510 /* Read the region size */
511 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
512 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
513
514 region->len = len;
515
516 /* Check if region length is -1. If that's the case, the shared memory
517 * region does not exist and there is no need to proceed further.
518 */
519 if (len == ~(u64)0)
520 return false;
521
522 /* Read the region base address */
523 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
524 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
525
526 region->addr = addr;
527
528 return true;
529 }
530
531 static const struct virtio_config_ops virtio_mmio_config_ops = {
532 .get = vm_get,
533 .set = vm_set,
534 .generation = vm_generation,
535 .get_status = vm_get_status,
536 .set_status = vm_set_status,
537 .reset = vm_reset,
538 .find_vqs = vm_find_vqs,
539 .del_vqs = vm_del_vqs,
540 .get_features = vm_get_features,
541 .finalize_features = vm_finalize_features,
542 .bus_name = vm_bus_name,
543 .get_shm_region = vm_get_shm_region,
544 };
545
546
virtio_mmio_release_dev(struct device * _d)547 static void virtio_mmio_release_dev(struct device *_d)
548 {
549 struct virtio_device *vdev =
550 container_of(_d, struct virtio_device, dev);
551 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
552 struct platform_device *pdev = vm_dev->pdev;
553
554 devm_kfree(&pdev->dev, vm_dev);
555 }
556
557 /* Platform device */
558
virtio_mmio_probe(struct platform_device * pdev)559 static int virtio_mmio_probe(struct platform_device *pdev)
560 {
561 struct virtio_mmio_device *vm_dev;
562 unsigned long magic;
563 int rc;
564
565 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
566 if (!vm_dev)
567 return -ENOMEM;
568
569 vm_dev->vdev.dev.parent = &pdev->dev;
570 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
571 vm_dev->vdev.config = &virtio_mmio_config_ops;
572 vm_dev->pdev = pdev;
573 INIT_LIST_HEAD(&vm_dev->virtqueues);
574 spin_lock_init(&vm_dev->lock);
575
576 vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
577 if (IS_ERR(vm_dev->base))
578 return PTR_ERR(vm_dev->base);
579
580 /* Check magic value */
581 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
582 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
583 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
584 return -ENODEV;
585 }
586
587 /* Check device version */
588 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
589 if (vm_dev->version < 1 || vm_dev->version > 2) {
590 dev_err(&pdev->dev, "Version %ld not supported!\n",
591 vm_dev->version);
592 return -ENXIO;
593 }
594
595 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
596 if (vm_dev->vdev.id.device == 0) {
597 /*
598 * virtio-mmio device with an ID 0 is a (dummy) placeholder
599 * with no function. End probing now with no error reported.
600 */
601 return -ENODEV;
602 }
603 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
604
605 if (vm_dev->version == 1) {
606 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
607
608 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
609 /*
610 * In the legacy case, ensure our coherently-allocated virtio
611 * ring will be at an address expressable as a 32-bit PFN.
612 */
613 if (!rc)
614 dma_set_coherent_mask(&pdev->dev,
615 DMA_BIT_MASK(32 + PAGE_SHIFT));
616 } else {
617 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
618 }
619 if (rc)
620 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
621 if (rc)
622 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
623
624 platform_set_drvdata(pdev, vm_dev);
625
626 rc = register_virtio_device(&vm_dev->vdev);
627 if (rc)
628 put_device(&vm_dev->vdev.dev);
629
630 return rc;
631 }
632
virtio_mmio_remove(struct platform_device * pdev)633 static int virtio_mmio_remove(struct platform_device *pdev)
634 {
635 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
636 unregister_virtio_device(&vm_dev->vdev);
637
638 return 0;
639 }
640
641
642
643 /* Devices list parameter */
644
645 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
646
647 static struct device vm_cmdline_parent = {
648 .init_name = "virtio-mmio-cmdline",
649 };
650
651 static int vm_cmdline_parent_registered;
652 static int vm_cmdline_id;
653
vm_cmdline_set(const char * device,const struct kernel_param * kp)654 static int vm_cmdline_set(const char *device,
655 const struct kernel_param *kp)
656 {
657 int err;
658 struct resource resources[2] = {};
659 char *str;
660 long long int base, size;
661 unsigned int irq;
662 int processed, consumed = 0;
663 struct platform_device *pdev;
664
665 /* Consume "size" part of the command line parameter */
666 size = memparse(device, &str);
667
668 /* Get "@<base>:<irq>[:<id>]" chunks */
669 processed = sscanf(str, "@%lli:%u%n:%d%n",
670 &base, &irq, &consumed,
671 &vm_cmdline_id, &consumed);
672
673 /*
674 * sscanf() must process at least 2 chunks; also there
675 * must be no extra characters after the last chunk, so
676 * str[consumed] must be '\0'
677 */
678 if (processed < 2 || str[consumed] || irq == 0)
679 return -EINVAL;
680
681 resources[0].flags = IORESOURCE_MEM;
682 resources[0].start = base;
683 resources[0].end = base + size - 1;
684
685 resources[1].flags = IORESOURCE_IRQ;
686 resources[1].start = resources[1].end = irq;
687
688 if (!vm_cmdline_parent_registered) {
689 err = device_register(&vm_cmdline_parent);
690 if (err) {
691 pr_err("Failed to register parent device!\n");
692 return err;
693 }
694 vm_cmdline_parent_registered = 1;
695 }
696
697 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
698 vm_cmdline_id,
699 (unsigned long long)resources[0].start,
700 (unsigned long long)resources[0].end,
701 (int)resources[1].start);
702
703 pdev = platform_device_register_resndata(&vm_cmdline_parent,
704 "virtio-mmio", vm_cmdline_id++,
705 resources, ARRAY_SIZE(resources), NULL, 0);
706
707 return PTR_ERR_OR_ZERO(pdev);
708 }
709
vm_cmdline_get_device(struct device * dev,void * data)710 static int vm_cmdline_get_device(struct device *dev, void *data)
711 {
712 char *buffer = data;
713 unsigned int len = strlen(buffer);
714 struct platform_device *pdev = to_platform_device(dev);
715
716 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
717 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
718 (unsigned long long)pdev->resource[0].start,
719 (unsigned long long)pdev->resource[1].start,
720 pdev->id);
721 return 0;
722 }
723
vm_cmdline_get(char * buffer,const struct kernel_param * kp)724 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
725 {
726 buffer[0] = '\0';
727 device_for_each_child(&vm_cmdline_parent, buffer,
728 vm_cmdline_get_device);
729 return strlen(buffer) + 1;
730 }
731
732 static const struct kernel_param_ops vm_cmdline_param_ops = {
733 .set = vm_cmdline_set,
734 .get = vm_cmdline_get,
735 };
736
737 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
738
vm_unregister_cmdline_device(struct device * dev,void * data)739 static int vm_unregister_cmdline_device(struct device *dev,
740 void *data)
741 {
742 platform_device_unregister(to_platform_device(dev));
743
744 return 0;
745 }
746
vm_unregister_cmdline_devices(void)747 static void vm_unregister_cmdline_devices(void)
748 {
749 if (vm_cmdline_parent_registered) {
750 device_for_each_child(&vm_cmdline_parent, NULL,
751 vm_unregister_cmdline_device);
752 device_unregister(&vm_cmdline_parent);
753 vm_cmdline_parent_registered = 0;
754 }
755 }
756
757 #else
758
vm_unregister_cmdline_devices(void)759 static void vm_unregister_cmdline_devices(void)
760 {
761 }
762
763 #endif
764
765 /* Platform driver */
766
767 static const struct of_device_id virtio_mmio_match[] = {
768 { .compatible = "virtio,mmio", },
769 {},
770 };
771 MODULE_DEVICE_TABLE(of, virtio_mmio_match);
772
773 #ifdef CONFIG_ACPI
774 static const struct acpi_device_id virtio_mmio_acpi_match[] = {
775 { "LNRO0005", },
776 { }
777 };
778 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
779 #endif
780
781 static struct platform_driver virtio_mmio_driver = {
782 .probe = virtio_mmio_probe,
783 .remove = virtio_mmio_remove,
784 .driver = {
785 .name = "virtio-mmio",
786 .of_match_table = virtio_mmio_match,
787 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
788 },
789 };
790
virtio_mmio_init(void)791 static int __init virtio_mmio_init(void)
792 {
793 return platform_driver_register(&virtio_mmio_driver);
794 }
795
virtio_mmio_exit(void)796 static void __exit virtio_mmio_exit(void)
797 {
798 platform_driver_unregister(&virtio_mmio_driver);
799 vm_unregister_cmdline_devices();
800 }
801
802 module_init(virtio_mmio_init);
803 module_exit(virtio_mmio_exit);
804
805 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
806 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
807 MODULE_LICENSE("GPL");
808
