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