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
84 struct 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
96 struct 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
vm_get_features(struct virtio_device * vdev)108 static 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
vm_finalize_features(struct virtio_device * vdev)123 static 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
vm_get(struct virtio_device * vdev,unsigned offset,void * buf,unsigned len)148 static void vm_get(struct virtio_device *vdev, unsigned offset,
149 void *buf, unsigned 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
vm_set(struct virtio_device * vdev,unsigned offset,const void * buf,unsigned len)190 static void vm_set(struct virtio_device *vdev, unsigned offset,
191 const void *buf, unsigned 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
vm_generation(struct virtio_device * vdev)233 static 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
vm_get_status(struct virtio_device * vdev)243 static 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
vm_set_status(struct virtio_device * vdev,u8 status)250 static 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 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
258 }
259
vm_reset(struct virtio_device * vdev)260 static void vm_reset(struct virtio_device *vdev)
261 {
262 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
263
264 /* 0 status means a reset. */
265 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
266 }
267
268
269
270 /* Transport interface */
271
272 /* the notify function used when creating a virt queue */
vm_notify(struct virtqueue * vq)273 static bool vm_notify(struct virtqueue *vq)
274 {
275 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
276
277 /* We write the queue's selector into the notification register to
278 * signal the other end */
279 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
280 return true;
281 }
282
283 /* Notify all virtqueues on an interrupt. */
vm_interrupt(int irq,void * opaque)284 static irqreturn_t vm_interrupt(int irq, void *opaque)
285 {
286 struct virtio_mmio_device *vm_dev = opaque;
287 struct virtio_mmio_vq_info *info;
288 unsigned long status;
289 unsigned long flags;
290 irqreturn_t ret = IRQ_NONE;
291
292 /* Read and acknowledge interrupts */
293 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
294 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
295
296 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
297 virtio_config_changed(&vm_dev->vdev);
298 ret = IRQ_HANDLED;
299 }
300
301 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
302 spin_lock_irqsave(&vm_dev->lock, flags);
303 list_for_each_entry(info, &vm_dev->virtqueues, node)
304 ret |= vring_interrupt(irq, info->vq);
305 spin_unlock_irqrestore(&vm_dev->lock, flags);
306 }
307
308 return ret;
309 }
310
311
312
vm_del_vq(struct virtqueue * vq)313 static void vm_del_vq(struct virtqueue *vq)
314 {
315 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
316 struct virtio_mmio_vq_info *info = vq->priv;
317 unsigned long flags;
318 unsigned int index = vq->index;
319
320 spin_lock_irqsave(&vm_dev->lock, flags);
321 list_del(&info->node);
322 spin_unlock_irqrestore(&vm_dev->lock, flags);
323
324 /* Select and deactivate the queue */
325 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
326 if (vm_dev->version == 1) {
327 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
328 } else {
329 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
330 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
331 }
332
333 vring_del_virtqueue(vq);
334
335 kfree(info);
336 }
337
vm_del_vqs(struct virtio_device * vdev)338 static void vm_del_vqs(struct virtio_device *vdev)
339 {
340 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
341 struct virtqueue *vq, *n;
342
343 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
344 vm_del_vq(vq);
345
346 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
347 }
348
vm_setup_vq(struct virtio_device * vdev,unsigned index,void (* callback)(struct virtqueue * vq),const char * name,bool ctx)349 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
350 void (*callback)(struct virtqueue *vq),
351 const char *name, bool ctx)
352 {
353 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
354 struct virtio_mmio_vq_info *info;
355 struct virtqueue *vq;
356 unsigned long flags;
357 unsigned int num;
358 int err;
359
360 if (!name)
361 return NULL;
362
363 /* Select the queue we're interested in */
364 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
365
366 /* Queue shouldn't already be set up. */
367 if (readl(vm_dev->base + (vm_dev->version == 1 ?
368 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
369 err = -ENOENT;
370 goto error_available;
371 }
372
373 /* Allocate and fill out our active queue description */
374 info = kmalloc(sizeof(*info), GFP_KERNEL);
375 if (!info) {
376 err = -ENOMEM;
377 goto error_kmalloc;
378 }
379
380 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
381 if (num == 0) {
382 err = -ENOENT;
383 goto error_new_virtqueue;
384 }
385
386 /* Create the vring */
387 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
388 true, true, ctx, vm_notify, callback, name);
389 if (!vq) {
390 err = -ENOMEM;
391 goto error_new_virtqueue;
392 }
393
394 /* Activate the queue */
395 writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
396 if (vm_dev->version == 1) {
397 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
398
399 /*
400 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
401 * that doesn't fit in 32bit, fail the setup rather than
402 * pretending to be successful.
403 */
404 if (q_pfn >> 32) {
405 dev_err(&vdev->dev,
406 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
407 0x1ULL << (32 + PAGE_SHIFT - 30));
408 err = -E2BIG;
409 goto error_bad_pfn;
410 }
411
412 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
413 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
414 } else {
415 u64 addr;
416
417 addr = virtqueue_get_desc_addr(vq);
418 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
419 writel((u32)(addr >> 32),
420 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
421
422 addr = virtqueue_get_avail_addr(vq);
423 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
424 writel((u32)(addr >> 32),
425 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
426
427 addr = virtqueue_get_used_addr(vq);
428 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
429 writel((u32)(addr >> 32),
430 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
431
432 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
433 }
434
435 vq->priv = info;
436 info->vq = vq;
437
438 spin_lock_irqsave(&vm_dev->lock, flags);
439 list_add(&info->node, &vm_dev->virtqueues);
440 spin_unlock_irqrestore(&vm_dev->lock, flags);
441
442 return vq;
443
444 error_bad_pfn:
445 vring_del_virtqueue(vq);
446 error_new_virtqueue:
447 if (vm_dev->version == 1) {
448 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
449 } else {
450 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
451 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
452 }
453 kfree(info);
454 error_kmalloc:
455 error_available:
456 return ERR_PTR(err);
457 }
458
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)459 static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
460 struct virtqueue *vqs[],
461 vq_callback_t *callbacks[],
462 const char * const names[],
463 const bool *ctx,
464 struct irq_affinity *desc)
465 {
466 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
467 int irq = platform_get_irq(vm_dev->pdev, 0);
468 int i, err, queue_idx = 0;
469
470 if (irq < 0)
471 return irq;
472
473 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
474 dev_name(&vdev->dev), vm_dev);
475 if (err)
476 return err;
477
478 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source"))
479 enable_irq_wake(irq);
480
481 for (i = 0; i < nvqs; ++i) {
482 if (!names[i]) {
483 vqs[i] = NULL;
484 continue;
485 }
486
487 vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
488 ctx ? ctx[i] : false);
489 if (IS_ERR(vqs[i])) {
490 vm_del_vqs(vdev);
491 return PTR_ERR(vqs[i]);
492 }
493 }
494
495 return 0;
496 }
497
vm_bus_name(struct virtio_device * vdev)498 static const char *vm_bus_name(struct virtio_device *vdev)
499 {
500 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
501
502 return vm_dev->pdev->name;
503 }
504
vm_get_shm_region(struct virtio_device * vdev,struct virtio_shm_region * region,u8 id)505 static bool vm_get_shm_region(struct virtio_device *vdev,
506 struct virtio_shm_region *region, u8 id)
507 {
508 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
509 u64 len, addr;
510
511 /* Select the region we're interested in */
512 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
513
514 /* Read the region size */
515 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
516 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
517
518 region->len = len;
519
520 /* Check if region length is -1. If that's the case, the shared memory
521 * region does not exist and there is no need to proceed further.
522 */
523 if (len == ~(u64)0)
524 return false;
525
526 /* Read the region base address */
527 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
528 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
529
530 region->addr = addr;
531
532 return true;
533 }
534
535 static const struct virtio_config_ops virtio_mmio_config_ops = {
536 .get = vm_get,
537 .set = vm_set,
538 .generation = vm_generation,
539 .get_status = vm_get_status,
540 .set_status = vm_set_status,
541 .reset = vm_reset,
542 .find_vqs = vm_find_vqs,
543 .del_vqs = vm_del_vqs,
544 .get_features = vm_get_features,
545 .finalize_features = vm_finalize_features,
546 .bus_name = vm_bus_name,
547 .get_shm_region = vm_get_shm_region,
548 };
549
550 #ifdef CONFIG_PM_SLEEP
virtio_mmio_freeze(struct device * dev)551 static int virtio_mmio_freeze(struct device *dev)
552 {
553 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
554
555 return virtio_device_freeze(&vm_dev->vdev);
556 }
557
virtio_mmio_restore(struct device * dev)558 static int virtio_mmio_restore(struct device *dev)
559 {
560 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
561
562 if (vm_dev->version == 1)
563 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
564
565 return virtio_device_restore(&vm_dev->vdev);
566 }
567
568 static const struct dev_pm_ops virtio_mmio_pm_ops = {
569 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore)
570 };
571 #endif
572
virtio_mmio_release_dev(struct device * _d)573 static void virtio_mmio_release_dev(struct device *_d)
574 {
575 struct virtio_device *vdev =
576 container_of(_d, struct virtio_device, dev);
577 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
578
579 kfree(vm_dev);
580 }
581
582 /* Platform device */
583
virtio_mmio_probe(struct platform_device * pdev)584 static int virtio_mmio_probe(struct platform_device *pdev)
585 {
586 struct virtio_mmio_device *vm_dev;
587 unsigned long magic;
588 int rc;
589
590 vm_dev = kzalloc(sizeof(*vm_dev), GFP_KERNEL);
591 if (!vm_dev)
592 return -ENOMEM;
593
594 vm_dev->vdev.dev.parent = &pdev->dev;
595 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
596 vm_dev->vdev.config = &virtio_mmio_config_ops;
597 vm_dev->pdev = pdev;
598 INIT_LIST_HEAD(&vm_dev->virtqueues);
599 spin_lock_init(&vm_dev->lock);
600
601 vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
602 if (IS_ERR(vm_dev->base)) {
603 rc = PTR_ERR(vm_dev->base);
604 goto free_vm_dev;
605 }
606
607 /* Check magic value */
608 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
609 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
610 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
611 rc = -ENODEV;
612 goto free_vm_dev;
613 }
614
615 /* Check device version */
616 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
617 if (vm_dev->version < 1 || vm_dev->version > 2) {
618 dev_err(&pdev->dev, "Version %ld not supported!\n",
619 vm_dev->version);
620 rc = -ENXIO;
621 goto free_vm_dev;
622 }
623
624 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
625 if (vm_dev->vdev.id.device == 0) {
626 /*
627 * virtio-mmio device with an ID 0 is a (dummy) placeholder
628 * with no function. End probing now with no error reported.
629 */
630 rc = -ENODEV;
631 goto free_vm_dev;
632 }
633 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
634
635 if (vm_dev->version == 1) {
636 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
637
638 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
639 /*
640 * In the legacy case, ensure our coherently-allocated virtio
641 * ring will be at an address expressable as a 32-bit PFN.
642 */
643 if (!rc)
644 dma_set_coherent_mask(&pdev->dev,
645 DMA_BIT_MASK(32 + PAGE_SHIFT));
646 } else {
647 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
648 }
649 if (rc)
650 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
651 if (rc)
652 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
653
654 platform_set_drvdata(pdev, vm_dev);
655
656 rc = register_virtio_device(&vm_dev->vdev);
657 if (rc)
658 put_device(&vm_dev->vdev.dev);
659
660 return rc;
661
662 free_vm_dev:
663 kfree(vm_dev);
664 return rc;
665 }
666
virtio_mmio_remove(struct platform_device * pdev)667 static int virtio_mmio_remove(struct platform_device *pdev)
668 {
669 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
670 unregister_virtio_device(&vm_dev->vdev);
671
672 return 0;
673 }
674
675
676
677 /* Devices list parameter */
678
679 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
680
681 static struct device vm_cmdline_parent = {
682 .init_name = "virtio-mmio-cmdline",
683 };
684
685 static int vm_cmdline_parent_registered;
686 static int vm_cmdline_id;
687
vm_cmdline_set(const char * device,const struct kernel_param * kp)688 static int vm_cmdline_set(const char *device,
689 const struct kernel_param *kp)
690 {
691 int err;
692 struct resource resources[2] = {};
693 char *str;
694 long long int base, size;
695 unsigned int irq;
696 int processed, consumed = 0;
697 struct platform_device *pdev;
698
699 /* Consume "size" part of the command line parameter */
700 size = memparse(device, &str);
701
702 /* Get "@<base>:<irq>[:<id>]" chunks */
703 processed = sscanf(str, "@%lli:%u%n:%d%n",
704 &base, &irq, &consumed,
705 &vm_cmdline_id, &consumed);
706
707 /*
708 * sscanf() must process at least 2 chunks; also there
709 * must be no extra characters after the last chunk, so
710 * str[consumed] must be '\0'
711 */
712 if (processed < 2 || str[consumed] || irq == 0)
713 return -EINVAL;
714
715 resources[0].flags = IORESOURCE_MEM;
716 resources[0].start = base;
717 resources[0].end = base + size - 1;
718
719 resources[1].flags = IORESOURCE_IRQ;
720 resources[1].start = resources[1].end = irq;
721
722 if (!vm_cmdline_parent_registered) {
723 err = device_register(&vm_cmdline_parent);
724 if (err) {
725 put_device(&vm_cmdline_parent);
726 pr_err("Failed to register parent device!\n");
727 return err;
728 }
729 vm_cmdline_parent_registered = 1;
730 }
731
732 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
733 vm_cmdline_id,
734 (unsigned long long)resources[0].start,
735 (unsigned long long)resources[0].end,
736 (int)resources[1].start);
737
738 pdev = platform_device_register_resndata(&vm_cmdline_parent,
739 "virtio-mmio", vm_cmdline_id++,
740 resources, ARRAY_SIZE(resources), NULL, 0);
741
742 return PTR_ERR_OR_ZERO(pdev);
743 }
744
vm_cmdline_get_device(struct device * dev,void * data)745 static int vm_cmdline_get_device(struct device *dev, void *data)
746 {
747 char *buffer = data;
748 unsigned int len = strlen(buffer);
749 struct platform_device *pdev = to_platform_device(dev);
750
751 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
752 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
753 (unsigned long long)pdev->resource[0].start,
754 (unsigned long long)pdev->resource[1].start,
755 pdev->id);
756 return 0;
757 }
758
vm_cmdline_get(char * buffer,const struct kernel_param * kp)759 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
760 {
761 buffer[0] = '\0';
762 device_for_each_child(&vm_cmdline_parent, buffer,
763 vm_cmdline_get_device);
764 return strlen(buffer) + 1;
765 }
766
767 static const struct kernel_param_ops vm_cmdline_param_ops = {
768 .set = vm_cmdline_set,
769 .get = vm_cmdline_get,
770 };
771
772 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
773
vm_unregister_cmdline_device(struct device * dev,void * data)774 static int vm_unregister_cmdline_device(struct device *dev,
775 void *data)
776 {
777 platform_device_unregister(to_platform_device(dev));
778
779 return 0;
780 }
781
vm_unregister_cmdline_devices(void)782 static void vm_unregister_cmdline_devices(void)
783 {
784 if (vm_cmdline_parent_registered) {
785 device_for_each_child(&vm_cmdline_parent, NULL,
786 vm_unregister_cmdline_device);
787 device_unregister(&vm_cmdline_parent);
788 vm_cmdline_parent_registered = 0;
789 }
790 }
791
792 #else
793
vm_unregister_cmdline_devices(void)794 static void vm_unregister_cmdline_devices(void)
795 {
796 }
797
798 #endif
799
800 /* Platform driver */
801
802 static const struct of_device_id virtio_mmio_match[] = {
803 { .compatible = "virtio,mmio", },
804 {},
805 };
806 MODULE_DEVICE_TABLE(of, virtio_mmio_match);
807
808 #ifdef CONFIG_ACPI
809 static const struct acpi_device_id virtio_mmio_acpi_match[] = {
810 { "LNRO0005", },
811 { }
812 };
813 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
814 #endif
815
816 static struct platform_driver virtio_mmio_driver = {
817 .probe = virtio_mmio_probe,
818 .remove = virtio_mmio_remove,
819 .driver = {
820 .name = "virtio-mmio",
821 .of_match_table = virtio_mmio_match,
822 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
823 #ifdef CONFIG_PM_SLEEP
824 .pm = &virtio_mmio_pm_ops,
825 #endif
826 },
827 };
828
virtio_mmio_init(void)829 static int __init virtio_mmio_init(void)
830 {
831 return platform_driver_register(&virtio_mmio_driver);
832 }
833
virtio_mmio_exit(void)834 static void __exit virtio_mmio_exit(void)
835 {
836 platform_driver_unregister(&virtio_mmio_driver);
837 vm_unregister_cmdline_devices();
838 }
839
840 module_init(virtio_mmio_init);
841 module_exit(virtio_mmio_exit);
842
843 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
844 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
845 MODULE_LICENSE("GPL");
846