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/delay.h>
59 #include <linux/dma-mapping.h>
60 #include <linux/highmem.h>
61 #include <linux/interrupt.h>
62 #include <linux/io.h>
63 #include <linux/list.h>
64 #include <linux/module.h>
65 #include <linux/of.h>
66 #include <linux/platform_device.h>
67 #include <linux/pm.h>
68 #include <linux/slab.h>
69 #include <linux/virtio.h>
70 #include <linux/virtio_config.h>
71 #include <uapi/linux/virtio_mmio.h>
72 #include <linux/virtio_ring.h>
73
74
75
76 /* The alignment to use between consumer and producer parts of vring.
77 * Currently hardcoded to the page size. */
78 #define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
79
80
81
82 #define to_virtio_mmio_device(_plat_dev) \
83 container_of(_plat_dev, struct virtio_mmio_device, vdev)
84
85 struct virtio_mmio_device {
86 struct virtio_device vdev;
87 struct platform_device *pdev;
88
89 void __iomem *base;
90 unsigned long version;
91 };
92
93 /* Configuration interface */
94
vm_get_features(struct virtio_device * vdev)95 static u64 vm_get_features(struct virtio_device *vdev)
96 {
97 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
98 u64 features;
99
100 writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
101 features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
102 features <<= 32;
103
104 writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
105 features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
106
107 return features;
108 }
109
vm_finalize_features(struct virtio_device * vdev)110 static int vm_finalize_features(struct virtio_device *vdev)
111 {
112 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
113
114 /* Give virtio_ring a chance to accept features. */
115 vring_transport_features(vdev);
116
117 /* Make sure there are no mixed devices */
118 if (vm_dev->version >= 2 &&
119 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
120 dev_err(&vdev->dev, "New virtio-mmio devices (version >= 2) must provide VIRTIO_F_VERSION_1 feature!\n");
121 return -EINVAL;
122 }
123
124 writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
125 writel((u32)(vdev->features >> 32),
126 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
127
128 writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
129 writel((u32)vdev->features,
130 vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
131
132 return 0;
133 }
134
vm_get(struct virtio_device * vdev,unsigned int offset,void * buf,unsigned int len)135 static void vm_get(struct virtio_device *vdev, unsigned int offset,
136 void *buf, unsigned int len)
137 {
138 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
139 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
140 u8 b;
141 __le16 w;
142 __le32 l;
143
144 if (vm_dev->version == 1) {
145 u8 *ptr = buf;
146 int i;
147
148 for (i = 0; i < len; i++)
149 ptr[i] = readb(base + offset + i);
150 return;
151 }
152
153 switch (len) {
154 case 1:
155 b = readb(base + offset);
156 memcpy(buf, &b, sizeof b);
157 break;
158 case 2:
159 w = cpu_to_le16(readw(base + offset));
160 memcpy(buf, &w, sizeof w);
161 break;
162 case 4:
163 l = cpu_to_le32(readl(base + offset));
164 memcpy(buf, &l, sizeof l);
165 break;
166 case 8:
167 l = cpu_to_le32(readl(base + offset));
168 memcpy(buf, &l, sizeof l);
169 l = cpu_to_le32(ioread32(base + offset + sizeof l));
170 memcpy(buf + sizeof l, &l, sizeof l);
171 break;
172 default:
173 BUG();
174 }
175 }
176
vm_set(struct virtio_device * vdev,unsigned int offset,const void * buf,unsigned int len)177 static void vm_set(struct virtio_device *vdev, unsigned int offset,
178 const void *buf, unsigned int len)
179 {
180 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
181 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
182 u8 b;
183 __le16 w;
184 __le32 l;
185
186 if (vm_dev->version == 1) {
187 const u8 *ptr = buf;
188 int i;
189
190 for (i = 0; i < len; i++)
191 writeb(ptr[i], base + offset + i);
192
193 return;
194 }
195
196 switch (len) {
197 case 1:
198 memcpy(&b, buf, sizeof b);
199 writeb(b, base + offset);
200 break;
201 case 2:
202 memcpy(&w, buf, sizeof w);
203 writew(le16_to_cpu(w), base + offset);
204 break;
205 case 4:
206 memcpy(&l, buf, sizeof l);
207 writel(le32_to_cpu(l), base + offset);
208 break;
209 case 8:
210 memcpy(&l, buf, sizeof l);
211 writel(le32_to_cpu(l), base + offset);
212 memcpy(&l, buf + sizeof l, sizeof l);
213 writel(le32_to_cpu(l), base + offset + sizeof l);
214 break;
215 default:
216 BUG();
217 }
218 }
219
vm_generation(struct virtio_device * vdev)220 static u32 vm_generation(struct virtio_device *vdev)
221 {
222 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
223
224 if (vm_dev->version == 1)
225 return 0;
226 else
227 return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
228 }
229
vm_get_status(struct virtio_device * vdev)230 static u8 vm_get_status(struct virtio_device *vdev)
231 {
232 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
233
234 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
235 }
236
vm_set_status(struct virtio_device * vdev,u8 status)237 static void vm_set_status(struct virtio_device *vdev, u8 status)
238 {
239 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
240
241 /* We should never be setting status to 0. */
242 BUG_ON(status == 0);
243
244 /*
245 * Per memory-barriers.txt, wmb() is not needed to guarantee
246 * that the cache coherent memory writes have completed
247 * before writing to the MMIO region.
248 */
249 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
250 }
251
vm_reset(struct virtio_device * vdev)252 static void vm_reset(struct virtio_device *vdev)
253 {
254 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
255
256 /* 0 status means a reset. */
257 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
258
259 if (vm_dev->version >= 3) {
260 /* Wait for reset to complete. */
261 while (vm_get_status(vdev))
262 fsleep(1000);
263 }
264 }
265
266
267
268 /* Transport interface */
269
270 /* the notify function used when creating a virt queue */
vm_notify(struct virtqueue * vq)271 static bool vm_notify(struct virtqueue *vq)
272 {
273 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
274
275 /* We write the queue's selector into the notification register to
276 * signal the other end */
277 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
278 return true;
279 }
280
vm_notify_with_data(struct virtqueue * vq)281 static bool vm_notify_with_data(struct virtqueue *vq)
282 {
283 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
284 u32 data = vring_notification_data(vq);
285
286 writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
287
288 return true;
289 }
290
291 /* Notify all virtqueues on an interrupt. */
vm_interrupt(int irq,void * opaque)292 static irqreturn_t vm_interrupt(int irq, void *opaque)
293 {
294 struct virtio_mmio_device *vm_dev = opaque;
295 struct virtqueue *vq;
296 unsigned long status;
297 irqreturn_t ret = IRQ_NONE;
298
299 /* Read and acknowledge interrupts */
300 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
301 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
302
303 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
304 virtio_config_changed(&vm_dev->vdev);
305 ret = IRQ_HANDLED;
306 }
307
308 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
309 virtio_device_for_each_vq(&vm_dev->vdev, vq)
310 ret |= vring_interrupt(irq, vq);
311 }
312
313 return ret;
314 }
315
316
317
vm_del_vq(struct virtqueue * vq)318 static void vm_del_vq(struct virtqueue *vq)
319 {
320 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
321 unsigned int index = vq->index;
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
vm_del_vqs(struct virtio_device * vdev)335 static void vm_del_vqs(struct virtio_device *vdev)
336 {
337 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
338 struct virtqueue *vq, *n;
339
340 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
341 vm_del_vq(vq);
342
343 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
344 }
345
vm_synchronize_cbs(struct virtio_device * vdev)346 static void vm_synchronize_cbs(struct virtio_device *vdev)
347 {
348 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
349
350 synchronize_irq(platform_get_irq(vm_dev->pdev, 0));
351 }
352
vm_setup_vq(struct virtio_device * vdev,unsigned int index,void (* callback)(struct virtqueue * vq),const char * name,bool ctx)353 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int 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 bool (*notify)(struct virtqueue *vq);
359 struct virtqueue *vq;
360 unsigned int num;
361 int err;
362
363 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
364 notify = vm_notify_with_data;
365 else
366 notify = vm_notify;
367
368 if (!name)
369 return NULL;
370
371 /* Select the queue we're interested in */
372 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
373
374 /* Queue shouldn't already be set up. */
375 if (readl(vm_dev->base + (vm_dev->version == 1 ?
376 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
377 err = -ENOENT;
378 goto error_available;
379 }
380
381 num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
382 if (num == 0) {
383 err = -ENOENT;
384 goto error_new_virtqueue;
385 }
386
387 /* Create the vring */
388 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
389 true, true, ctx, notify, callback, name);
390 if (!vq) {
391 err = -ENOMEM;
392 goto error_new_virtqueue;
393 }
394
395 vq->num_max = num;
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 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
401
402 /*
403 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
404 * that doesn't fit in 32bit, fail the setup rather than
405 * pretending to be successful.
406 */
407 if (q_pfn >> 32) {
408 dev_err(&vdev->dev,
409 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
410 0x1ULL << (32 + PAGE_SHIFT - 30));
411 err = -E2BIG;
412 goto error_bad_pfn;
413 }
414
415 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
416 writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
417 } else {
418 u64 addr;
419
420 addr = virtqueue_get_desc_addr(vq);
421 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
422 writel((u32)(addr >> 32),
423 vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
424
425 addr = virtqueue_get_avail_addr(vq);
426 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
427 writel((u32)(addr >> 32),
428 vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
429
430 addr = virtqueue_get_used_addr(vq);
431 writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
432 writel((u32)(addr >> 32),
433 vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
434
435 writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
436 }
437
438 return vq;
439
440 error_bad_pfn:
441 vring_del_virtqueue(vq);
442 error_new_virtqueue:
443 if (vm_dev->version == 1) {
444 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
445 } else {
446 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
447 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
448 }
449 error_available:
450 return ERR_PTR(err);
451 }
452
vm_find_vqs(struct virtio_device * vdev,unsigned int nvqs,struct virtqueue * vqs[],struct virtqueue_info vqs_info[],struct irq_affinity * desc)453 static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
454 struct virtqueue *vqs[],
455 struct virtqueue_info vqs_info[],
456 struct irq_affinity *desc)
457 {
458 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
459 int irq = platform_get_irq(vm_dev->pdev, 0);
460 int i, err, queue_idx = 0;
461
462 if (irq < 0)
463 return irq;
464
465 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
466 dev_name(&vdev->dev), vm_dev);
467 if (err)
468 return err;
469
470 if (of_property_read_bool(vm_dev->pdev->dev.of_node, "wakeup-source"))
471 enable_irq_wake(irq);
472
473 for (i = 0; i < nvqs; ++i) {
474 struct virtqueue_info *vqi = &vqs_info[i];
475
476 if (!vqi->name) {
477 vqs[i] = NULL;
478 continue;
479 }
480
481 vqs[i] = vm_setup_vq(vdev, queue_idx++, vqi->callback,
482 vqi->name, vqi->ctx);
483 if (IS_ERR(vqs[i])) {
484 vm_del_vqs(vdev);
485 return PTR_ERR(vqs[i]);
486 }
487 }
488
489 return 0;
490 }
491
vm_bus_name(struct virtio_device * vdev)492 static const char *vm_bus_name(struct virtio_device *vdev)
493 {
494 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
495
496 return vm_dev->pdev->name;
497 }
498
vm_get_shm_region(struct virtio_device * vdev,struct virtio_shm_region * region,u8 id)499 static bool vm_get_shm_region(struct virtio_device *vdev,
500 struct virtio_shm_region *region, u8 id)
501 {
502 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
503 u64 len, addr;
504
505 /* Select the region we're interested in */
506 writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
507
508 /* Read the region size */
509 len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
510 len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
511
512 region->len = len;
513
514 /* Check if region length is -1. If that's the case, the shared memory
515 * region does not exist and there is no need to proceed further.
516 */
517 if (len == ~(u64)0)
518 return false;
519
520 /* Read the region base address */
521 addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
522 addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
523
524 region->addr = addr;
525
526 return true;
527 }
528
529 static const struct virtio_config_ops virtio_mmio_config_ops = {
530 .get = vm_get,
531 .set = vm_set,
532 .generation = vm_generation,
533 .get_status = vm_get_status,
534 .set_status = vm_set_status,
535 .reset = vm_reset,
536 .find_vqs = vm_find_vqs,
537 .del_vqs = vm_del_vqs,
538 .get_features = vm_get_features,
539 .finalize_features = vm_finalize_features,
540 .bus_name = vm_bus_name,
541 .get_shm_region = vm_get_shm_region,
542 .synchronize_cbs = vm_synchronize_cbs,
543 };
544
545 #ifdef CONFIG_PM_SLEEP
virtio_mmio_freeze(struct device * dev)546 static int virtio_mmio_freeze(struct device *dev)
547 {
548 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
549
550 return virtio_device_freeze(&vm_dev->vdev);
551 }
552
virtio_mmio_restore(struct device * dev)553 static int virtio_mmio_restore(struct device *dev)
554 {
555 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
556
557 if (vm_dev->version == 1)
558 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
559
560 return virtio_device_restore(&vm_dev->vdev);
561 }
562
563 static const struct dev_pm_ops virtio_mmio_pm_ops = {
564 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore)
565 };
566 #endif
567
virtio_mmio_release_dev(struct device * _d)568 static void virtio_mmio_release_dev(struct device *_d)
569 {
570 struct virtio_device *vdev =
571 container_of(_d, struct virtio_device, dev);
572 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
573
574 kfree(vm_dev);
575 }
576
577 /* Platform device */
578
virtio_mmio_probe(struct platform_device * pdev)579 static int virtio_mmio_probe(struct platform_device *pdev)
580 {
581 struct virtio_mmio_device *vm_dev;
582 unsigned long magic;
583 int rc;
584
585 vm_dev = kzalloc_obj(*vm_dev);
586 if (!vm_dev)
587 return -ENOMEM;
588
589 vm_dev->vdev.dev.parent = &pdev->dev;
590 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
591 vm_dev->vdev.config = &virtio_mmio_config_ops;
592 vm_dev->pdev = pdev;
593
594 vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
595 if (IS_ERR(vm_dev->base)) {
596 rc = PTR_ERR(vm_dev->base);
597 goto free_vm_dev;
598 }
599
600 /* Check magic value */
601 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
602 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
603 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
604 rc = -ENODEV;
605 goto free_vm_dev;
606 }
607
608 /* Check device version */
609 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
610 if (vm_dev->version < 1 || vm_dev->version > 3) {
611 dev_err(&pdev->dev, "Version %ld not supported!\n",
612 vm_dev->version);
613 rc = -ENXIO;
614 goto free_vm_dev;
615 }
616
617 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
618 if (vm_dev->vdev.id.device == 0) {
619 /*
620 * virtio-mmio device with an ID 0 is a (dummy) placeholder
621 * with no function. End probing now with no error reported.
622 */
623 rc = -ENODEV;
624 goto free_vm_dev;
625 }
626 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
627
628 if (vm_dev->version == 1) {
629 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
630
631 rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
632 /*
633 * In the legacy case, ensure our coherently-allocated virtio
634 * ring will be at an address expressable as a 32-bit PFN.
635 */
636 if (!rc)
637 dma_set_coherent_mask(&pdev->dev,
638 DMA_BIT_MASK(32 + PAGE_SHIFT));
639 } else {
640 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
641 }
642 if (rc)
643 rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
644 if (rc)
645 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
646
647 platform_set_drvdata(pdev, vm_dev);
648
649 rc = register_virtio_device(&vm_dev->vdev);
650 if (rc)
651 put_device(&vm_dev->vdev.dev);
652
653 return rc;
654
655 free_vm_dev:
656 kfree(vm_dev);
657 return rc;
658 }
659
virtio_mmio_remove(struct platform_device * pdev)660 static void virtio_mmio_remove(struct platform_device *pdev)
661 {
662 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
663 unregister_virtio_device(&vm_dev->vdev);
664 }
665
666
667
668 /* Devices list parameter */
669
670 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
671
672 static struct device *vm_cmdline_parent;
673
674 static int vm_cmdline_parent_registered;
675 static int vm_cmdline_id;
676
vm_cmdline_set(const char * device,const struct kernel_param * kp)677 static int vm_cmdline_set(const char *device,
678 const struct kernel_param *kp)
679 {
680 struct resource resources[2] = {};
681 char *str;
682 long long base, size;
683 unsigned int irq;
684 int processed, consumed = 0;
685 struct platform_device *pdev;
686
687 /* Consume "size" part of the command line parameter */
688 size = memparse(device, &str);
689
690 /* Get "@<base>:<irq>[:<id>]" chunks */
691 processed = sscanf(str, "@%lli:%u%n:%d%n",
692 &base, &irq, &consumed,
693 &vm_cmdline_id, &consumed);
694
695 /*
696 * sscanf() must process at least 2 chunks; also there
697 * must be no extra characters after the last chunk, so
698 * str[consumed] must be '\0'
699 */
700 if (processed < 2 || str[consumed] || irq == 0)
701 return -EINVAL;
702
703 resources[0].flags = IORESOURCE_MEM;
704 resources[0].start = base;
705 resources[0].end = base + size - 1;
706
707 resources[1].flags = IORESOURCE_IRQ;
708 resources[1].start = resources[1].end = irq;
709
710 if (!vm_cmdline_parent_registered) {
711 vm_cmdline_parent = __root_device_register("virtio-mmio-cmdline", NULL);
712 if (IS_ERR(vm_cmdline_parent)) {
713 pr_err("Failed to register parent device!\n");
714 return PTR_ERR(vm_cmdline_parent);
715 }
716 vm_cmdline_parent_registered = 1;
717 }
718
719 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
720 vm_cmdline_id,
721 (unsigned long long)resources[0].start,
722 (unsigned long long)resources[0].end,
723 (int)resources[1].start);
724
725 pdev = platform_device_register_resndata(vm_cmdline_parent,
726 "virtio-mmio", vm_cmdline_id++,
727 resources, ARRAY_SIZE(resources), NULL, 0);
728
729 return PTR_ERR_OR_ZERO(pdev);
730 }
731
vm_cmdline_get_device(struct device * dev,void * data)732 static int vm_cmdline_get_device(struct device *dev, void *data)
733 {
734 char *buffer = data;
735 unsigned int len = strlen(buffer);
736 struct platform_device *pdev = to_platform_device(dev);
737
738 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
739 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
740 (unsigned long long)pdev->resource[0].start,
741 (unsigned long long)pdev->resource[1].start,
742 pdev->id);
743 return 0;
744 }
745
vm_cmdline_get(char * buffer,const struct kernel_param * kp)746 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
747 {
748 buffer[0] = '\0';
749
750 if (vm_cmdline_parent_registered) {
751 device_for_each_child(vm_cmdline_parent, buffer,
752 vm_cmdline_get_device);
753 }
754
755 return strlen(buffer) + 1;
756 }
757
758 static const struct kernel_param_ops vm_cmdline_param_ops = {
759 .set = vm_cmdline_set,
760 .get = vm_cmdline_get,
761 };
762
763 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
764
vm_unregister_cmdline_device(struct device * dev,void * data)765 static int vm_unregister_cmdline_device(struct device *dev,
766 void *data)
767 {
768 platform_device_unregister(to_platform_device(dev));
769
770 return 0;
771 }
772
vm_unregister_cmdline_devices(void)773 static void vm_unregister_cmdline_devices(void)
774 {
775 if (vm_cmdline_parent_registered) {
776 device_for_each_child(vm_cmdline_parent, NULL,
777 vm_unregister_cmdline_device);
778 root_device_unregister(vm_cmdline_parent);
779 vm_cmdline_parent_registered = 0;
780 }
781 }
782
783 #else
784
vm_unregister_cmdline_devices(void)785 static void vm_unregister_cmdline_devices(void)
786 {
787 }
788
789 #endif
790
791 /* Platform driver */
792
793 static const struct of_device_id virtio_mmio_match[] = {
794 { .compatible = "virtio,mmio", },
795 {},
796 };
797 MODULE_DEVICE_TABLE(of, virtio_mmio_match);
798
799 #ifdef CONFIG_ACPI
800 static const struct acpi_device_id virtio_mmio_acpi_match[] = {
801 { "LNRO0005", },
802 { }
803 };
804 MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
805 #endif
806
807 static struct platform_driver virtio_mmio_driver = {
808 .probe = virtio_mmio_probe,
809 .remove = virtio_mmio_remove,
810 .driver = {
811 .name = "virtio-mmio",
812 .of_match_table = virtio_mmio_match,
813 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
814 #ifdef CONFIG_PM_SLEEP
815 .pm = &virtio_mmio_pm_ops,
816 #endif
817 },
818 };
819
virtio_mmio_init(void)820 static int __init virtio_mmio_init(void)
821 {
822 return platform_driver_register(&virtio_mmio_driver);
823 }
824
virtio_mmio_exit(void)825 static void __exit virtio_mmio_exit(void)
826 {
827 platform_driver_unregister(&virtio_mmio_driver);
828 vm_unregister_cmdline_devices();
829 }
830
831 module_init(virtio_mmio_init);
832 module_exit(virtio_mmio_exit);
833
834 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
835 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
836 MODULE_LICENSE("GPL");
837