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/of.h>
65#include <linux/platform_device.h>
66#include <linux/pm.h>
67#include <linux/slab.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
84struct virtio_mmio_device {
85 struct virtio_device vdev;
86 struct platform_device *pdev;
87
88 void __iomem *base;
89 unsigned long version;
90};
91
92/* Configuration interface */
93
94static u64 vm_get_features(struct virtio_device *vdev)
95{
96 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
97 u64 features;
98
99 writel(val: 1, addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
100 features = readl(addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
101 features <<= 32;
102
103 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
104 features |= readl(addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
105
106 return features;
107}
108
109static int vm_finalize_features(struct virtio_device *vdev)
110{
111 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
112
113 /* Give virtio_ring a chance to accept features. */
114 vring_transport_features(vdev);
115
116 /* Make sure there are no mixed devices */
117 if (vm_dev->version == 2 &&
118 !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
119 dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
120 return -EINVAL;
121 }
122
123 writel(val: 1, addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
124 writel(val: (u32)(vdev->features >> 32),
125 addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
126
127 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
128 writel(val: (u32)vdev->features,
129 addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
130
131 return 0;
132}
133
134static void vm_get(struct virtio_device *vdev, unsigned int offset,
135 void *buf, unsigned int len)
136{
137 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
138 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
139 u8 b;
140 __le16 w;
141 __le32 l;
142
143 if (vm_dev->version == 1) {
144 u8 *ptr = buf;
145 int i;
146
147 for (i = 0; i < len; i++)
148 ptr[i] = readb(addr: base + offset + i);
149 return;
150 }
151
152 switch (len) {
153 case 1:
154 b = readb(addr: base + offset);
155 memcpy(buf, &b, sizeof b);
156 break;
157 case 2:
158 w = cpu_to_le16(readw(base + offset));
159 memcpy(buf, &w, sizeof w);
160 break;
161 case 4:
162 l = cpu_to_le32(readl(base + offset));
163 memcpy(buf, &l, sizeof l);
164 break;
165 case 8:
166 l = cpu_to_le32(readl(base + offset));
167 memcpy(buf, &l, sizeof l);
168 l = cpu_to_le32(ioread32(base + offset + sizeof l));
169 memcpy(buf + sizeof l, &l, sizeof l);
170 break;
171 default:
172 BUG();
173 }
174}
175
176static void vm_set(struct virtio_device *vdev, unsigned int offset,
177 const void *buf, unsigned int len)
178{
179 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
180 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
181 u8 b;
182 __le16 w;
183 __le32 l;
184
185 if (vm_dev->version == 1) {
186 const u8 *ptr = buf;
187 int i;
188
189 for (i = 0; i < len; i++)
190 writeb(val: ptr[i], addr: base + offset + i);
191
192 return;
193 }
194
195 switch (len) {
196 case 1:
197 memcpy(&b, buf, sizeof b);
198 writeb(val: b, addr: base + offset);
199 break;
200 case 2:
201 memcpy(&w, buf, sizeof w);
202 writew(le16_to_cpu(w), addr: base + offset);
203 break;
204 case 4:
205 memcpy(&l, buf, sizeof l);
206 writel(le32_to_cpu(l), addr: base + offset);
207 break;
208 case 8:
209 memcpy(&l, buf, sizeof l);
210 writel(le32_to_cpu(l), addr: base + offset);
211 memcpy(&l, buf + sizeof l, sizeof l);
212 writel(le32_to_cpu(l), addr: base + offset + sizeof l);
213 break;
214 default:
215 BUG();
216 }
217}
218
219static u32 vm_generation(struct virtio_device *vdev)
220{
221 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
222
223 if (vm_dev->version == 1)
224 return 0;
225 else
226 return readl(addr: vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
227}
228
229static u8 vm_get_status(struct virtio_device *vdev)
230{
231 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
232
233 return readl(addr: vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
234}
235
236static void vm_set_status(struct virtio_device *vdev, u8 status)
237{
238 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
239
240 /* We should never be setting status to 0. */
241 BUG_ON(status == 0);
242
243 /*
244 * Per memory-barriers.txt, wmb() is not needed to guarantee
245 * that the cache coherent memory writes have completed
246 * before writing to the MMIO region.
247 */
248 writel(val: status, addr: vm_dev->base + VIRTIO_MMIO_STATUS);
249}
250
251static void vm_reset(struct virtio_device *vdev)
252{
253 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
254
255 /* 0 status means a reset. */
256 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_STATUS);
257}
258
259
260
261/* Transport interface */
262
263/* the notify function used when creating a virt queue */
264static bool vm_notify(struct virtqueue *vq)
265{
266 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
267
268 /* We write the queue's selector into the notification register to
269 * signal the other end */
270 writel(val: vq->index, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
271 return true;
272}
273
274static bool vm_notify_with_data(struct virtqueue *vq)
275{
276 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
277 u32 data = vring_notification_data(vq: vq);
278
279 writel(val: data, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
280
281 return true;
282}
283
284/* Notify all virtqueues on an interrupt. */
285static irqreturn_t vm_interrupt(int irq, void *opaque)
286{
287 struct virtio_mmio_device *vm_dev = opaque;
288 struct virtqueue *vq;
289 unsigned long status;
290 irqreturn_t ret = IRQ_NONE;
291
292 /* Read and acknowledge interrupts */
293 status = readl(addr: vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
294 writel(val: status, addr: vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
295
296 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
297 virtio_config_changed(dev: &vm_dev->vdev);
298 ret = IRQ_HANDLED;
299 }
300
301 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
302 virtio_device_for_each_vq(&vm_dev->vdev, vq)
303 ret |= vring_interrupt(irq, vq: vq);
304 }
305
306 return ret;
307}
308
309
310
311static void vm_del_vq(struct virtqueue *vq)
312{
313 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
314 unsigned int index = vq->index;
315
316 /* Select and deactivate the queue */
317 writel(val: index, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
318 if (vm_dev->version == 1) {
319 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
320 } else {
321 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
322 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
323 }
324
325 vring_del_virtqueue(vq);
326}
327
328static void vm_del_vqs(struct virtio_device *vdev)
329{
330 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
331 struct virtqueue *vq, *n;
332
333 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
334 vm_del_vq(vq);
335
336 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
337}
338
339static void vm_synchronize_cbs(struct virtio_device *vdev)
340{
341 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
342
343 synchronize_irq(irq: platform_get_irq(vm_dev->pdev, 0));
344}
345
346static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index,
347 void (*callback)(struct virtqueue *vq),
348 const char *name, bool ctx)
349{
350 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
351 bool (*notify)(struct virtqueue *vq);
352 struct virtqueue *vq;
353 unsigned int num;
354 int err;
355
356 if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
357 notify = vm_notify_with_data;
358 else
359 notify = vm_notify;
360
361 if (!name)
362 return NULL;
363
364 /* Select the queue we're interested in */
365 writel(val: index, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
366
367 /* Queue shouldn't already be set up. */
368 if (readl(addr: vm_dev->base + (vm_dev->version == 1 ?
369 VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
370 err = -ENOENT;
371 goto error_available;
372 }
373
374 num = readl(addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
375 if (num == 0) {
376 err = -ENOENT;
377 goto error_new_virtqueue;
378 }
379
380 /* Create the vring */
381 vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
382 weak_barriers: true, may_reduce_num: true, ctx, notify, callback, name);
383 if (!vq) {
384 err = -ENOMEM;
385 goto error_new_virtqueue;
386 }
387
388 vq->num_max = num;
389
390 /* Activate the queue */
391 writel(val: virtqueue_get_vring_size(vq), addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
392 if (vm_dev->version == 1) {
393 u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
394
395 /*
396 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
397 * that doesn't fit in 32bit, fail the setup rather than
398 * pretending to be successful.
399 */
400 if (q_pfn >> 32) {
401 dev_err(&vdev->dev,
402 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
403 0x1ULL << (32 + PAGE_SHIFT - 30));
404 err = -E2BIG;
405 goto error_bad_pfn;
406 }
407
408 writel(PAGE_SIZE, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
409 writel(val: q_pfn, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
410 } else {
411 u64 addr;
412
413 addr = virtqueue_get_desc_addr(vq);
414 writel(val: (u32)addr, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
415 writel(val: (u32)(addr >> 32),
416 addr: vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
417
418 addr = virtqueue_get_avail_addr(vq);
419 writel(val: (u32)addr, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
420 writel(val: (u32)(addr >> 32),
421 addr: vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
422
423 addr = virtqueue_get_used_addr(vq);
424 writel(val: (u32)addr, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
425 writel(val: (u32)(addr >> 32),
426 addr: vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
427
428 writel(val: 1, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
429 }
430
431 return vq;
432
433error_bad_pfn:
434 vring_del_virtqueue(vq);
435error_new_virtqueue:
436 if (vm_dev->version == 1) {
437 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
438 } else {
439 writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
440 WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
441 }
442error_available:
443 return ERR_PTR(error: err);
444}
445
446static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
447 struct virtqueue *vqs[],
448 struct virtqueue_info vqs_info[],
449 struct irq_affinity *desc)
450{
451 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
452 int irq = platform_get_irq(vm_dev->pdev, 0);
453 int i, err, queue_idx = 0;
454
455 if (irq < 0)
456 return irq;
457
458 err = request_irq(irq, handler: vm_interrupt, IRQF_SHARED,
459 name: dev_name(dev: &vdev->dev), dev: vm_dev);
460 if (err)
461 return err;
462
463 if (of_property_read_bool(np: vm_dev->pdev->dev.of_node, propname: "wakeup-source"))
464 enable_irq_wake(irq);
465
466 for (i = 0; i < nvqs; ++i) {
467 struct virtqueue_info *vqi = &vqs_info[i];
468
469 if (!vqi->name) {
470 vqs[i] = NULL;
471 continue;
472 }
473
474 vqs[i] = vm_setup_vq(vdev, index: queue_idx++, callback: vqi->callback,
475 name: vqi->name, ctx: vqi->ctx);
476 if (IS_ERR(ptr: vqs[i])) {
477 vm_del_vqs(vdev);
478 return PTR_ERR(ptr: vqs[i]);
479 }
480 }
481
482 return 0;
483}
484
485static const char *vm_bus_name(struct virtio_device *vdev)
486{
487 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
488
489 return vm_dev->pdev->name;
490}
491
492static bool vm_get_shm_region(struct virtio_device *vdev,
493 struct virtio_shm_region *region, u8 id)
494{
495 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
496 u64 len, addr;
497
498 /* Select the region we're interested in */
499 writel(val: id, addr: vm_dev->base + VIRTIO_MMIO_SHM_SEL);
500
501 /* Read the region size */
502 len = (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
503 len |= (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
504
505 region->len = len;
506
507 /* Check if region length is -1. If that's the case, the shared memory
508 * region does not exist and there is no need to proceed further.
509 */
510 if (len == ~(u64)0)
511 return false;
512
513 /* Read the region base address */
514 addr = (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
515 addr |= (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
516
517 region->addr = addr;
518
519 return true;
520}
521
522static const struct virtio_config_ops virtio_mmio_config_ops = {
523 .get = vm_get,
524 .set = vm_set,
525 .generation = vm_generation,
526 .get_status = vm_get_status,
527 .set_status = vm_set_status,
528 .reset = vm_reset,
529 .find_vqs = vm_find_vqs,
530 .del_vqs = vm_del_vqs,
531 .get_features = vm_get_features,
532 .finalize_features = vm_finalize_features,
533 .bus_name = vm_bus_name,
534 .get_shm_region = vm_get_shm_region,
535 .synchronize_cbs = vm_synchronize_cbs,
536};
537
538#ifdef CONFIG_PM_SLEEP
539static int virtio_mmio_freeze(struct device *dev)
540{
541 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
542
543 return virtio_device_freeze(dev: &vm_dev->vdev);
544}
545
546static int virtio_mmio_restore(struct device *dev)
547{
548 struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev);
549
550 if (vm_dev->version == 1)
551 writel(PAGE_SIZE, addr: vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
552
553 return virtio_device_restore(dev: &vm_dev->vdev);
554}
555
556static const struct dev_pm_ops virtio_mmio_pm_ops = {
557 SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore)
558};
559#endif
560
561static void virtio_mmio_release_dev(struct device *_d)
562{
563 struct virtio_device *vdev =
564 container_of(_d, struct virtio_device, dev);
565 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
566
567 kfree(objp: vm_dev);
568}
569
570/* Platform device */
571
572static int virtio_mmio_probe(struct platform_device *pdev)
573{
574 struct virtio_mmio_device *vm_dev;
575 unsigned long magic;
576 int rc;
577
578 vm_dev = kzalloc(sizeof(*vm_dev), GFP_KERNEL);
579 if (!vm_dev)
580 return -ENOMEM;
581
582 vm_dev->vdev.dev.parent = &pdev->dev;
583 vm_dev->vdev.dev.release = virtio_mmio_release_dev;
584 vm_dev->vdev.config = &virtio_mmio_config_ops;
585 vm_dev->pdev = pdev;
586
587 vm_dev->base = devm_platform_ioremap_resource(pdev, index: 0);
588 if (IS_ERR(ptr: vm_dev->base)) {
589 rc = PTR_ERR(ptr: vm_dev->base);
590 goto free_vm_dev;
591 }
592
593 /* Check magic value */
594 magic = readl(addr: vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
595 if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
596 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
597 rc = -ENODEV;
598 goto free_vm_dev;
599 }
600
601 /* Check device version */
602 vm_dev->version = readl(addr: vm_dev->base + VIRTIO_MMIO_VERSION);
603 if (vm_dev->version < 1 || vm_dev->version > 2) {
604 dev_err(&pdev->dev, "Version %ld not supported!\n",
605 vm_dev->version);
606 rc = -ENXIO;
607 goto free_vm_dev;
608 }
609
610 vm_dev->vdev.id.device = readl(addr: vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
611 if (vm_dev->vdev.id.device == 0) {
612 /*
613 * virtio-mmio device with an ID 0 is a (dummy) placeholder
614 * with no function. End probing now with no error reported.
615 */
616 rc = -ENODEV;
617 goto free_vm_dev;
618 }
619 vm_dev->vdev.id.vendor = readl(addr: vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
620
621 if (vm_dev->version == 1) {
622 writel(PAGE_SIZE, addr: vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
623
624 rc = dma_set_mask(dev: &pdev->dev, DMA_BIT_MASK(64));
625 /*
626 * In the legacy case, ensure our coherently-allocated virtio
627 * ring will be at an address expressable as a 32-bit PFN.
628 */
629 if (!rc)
630 dma_set_coherent_mask(dev: &pdev->dev,
631 DMA_BIT_MASK(32 + PAGE_SHIFT));
632 } else {
633 rc = dma_set_mask_and_coherent(dev: &pdev->dev, DMA_BIT_MASK(64));
634 }
635 if (rc)
636 rc = dma_set_mask_and_coherent(dev: &pdev->dev, DMA_BIT_MASK(32));
637 if (rc)
638 dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
639
640 platform_set_drvdata(pdev, data: vm_dev);
641
642 rc = register_virtio_device(dev: &vm_dev->vdev);
643 if (rc)
644 put_device(dev: &vm_dev->vdev.dev);
645
646 return rc;
647
648free_vm_dev:
649 kfree(objp: vm_dev);
650 return rc;
651}
652
653static void virtio_mmio_remove(struct platform_device *pdev)
654{
655 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
656 unregister_virtio_device(dev: &vm_dev->vdev);
657}
658
659
660
661/* Devices list parameter */
662
663#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
664
665static struct device vm_cmdline_parent = {
666 .init_name = "virtio-mmio-cmdline",
667};
668
669static int vm_cmdline_parent_registered;
670static int vm_cmdline_id;
671
672static int vm_cmdline_set(const char *device,
673 const struct kernel_param *kp)
674{
675 int err;
676 struct resource resources[2] = {};
677 char *str;
678 long long base, size;
679 unsigned int irq;
680 int processed, consumed = 0;
681 struct platform_device *pdev;
682
683 /* Consume "size" part of the command line parameter */
684 size = memparse(ptr: device, retptr: &str);
685
686 /* Get "@<base>:<irq>[:<id>]" chunks */
687 processed = sscanf(str, "@%lli:%u%n:%d%n",
688 &base, &irq, &consumed,
689 &vm_cmdline_id, &consumed);
690
691 /*
692 * sscanf() must process at least 2 chunks; also there
693 * must be no extra characters after the last chunk, so
694 * str[consumed] must be '\0'
695 */
696 if (processed < 2 || str[consumed] || irq == 0)
697 return -EINVAL;
698
699 resources[0].flags = IORESOURCE_MEM;
700 resources[0].start = base;
701 resources[0].end = base + size - 1;
702
703 resources[1].flags = IORESOURCE_IRQ;
704 resources[1].start = resources[1].end = irq;
705
706 if (!vm_cmdline_parent_registered) {
707 err = device_register(dev: &vm_cmdline_parent);
708 if (err) {
709 put_device(dev: &vm_cmdline_parent);
710 pr_err("Failed to register parent device!\n");
711 return err;
712 }
713 vm_cmdline_parent_registered = 1;
714 }
715
716 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
717 vm_cmdline_id,
718 (unsigned long long)resources[0].start,
719 (unsigned long long)resources[0].end,
720 (int)resources[1].start);
721
722 pdev = platform_device_register_resndata(parent: &vm_cmdline_parent,
723 name: "virtio-mmio", id: vm_cmdline_id++,
724 res: resources, ARRAY_SIZE(resources), NULL, size: 0);
725
726 return PTR_ERR_OR_ZERO(ptr: pdev);
727}
728
729static int vm_cmdline_get_device(struct device *dev, void *data)
730{
731 char *buffer = data;
732 unsigned int len = strlen(buffer);
733 struct platform_device *pdev = to_platform_device(dev);
734
735 snprintf(buf: buffer + len, PAGE_SIZE - len, fmt: "0x%llx@0x%llx:%llu:%d\n",
736 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
737 (unsigned long long)pdev->resource[0].start,
738 (unsigned long long)pdev->resource[1].start,
739 pdev->id);
740 return 0;
741}
742
743static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
744{
745 buffer[0] = '\0';
746 device_for_each_child(parent: &vm_cmdline_parent, data: buffer,
747 fn: vm_cmdline_get_device);
748 return strlen(buffer) + 1;
749}
750
751static const struct kernel_param_ops vm_cmdline_param_ops = {
752 .set = vm_cmdline_set,
753 .get = vm_cmdline_get,
754};
755
756device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
757
758static int vm_unregister_cmdline_device(struct device *dev,
759 void *data)
760{
761 platform_device_unregister(to_platform_device(dev));
762
763 return 0;
764}
765
766static void vm_unregister_cmdline_devices(void)
767{
768 if (vm_cmdline_parent_registered) {
769 device_for_each_child(parent: &vm_cmdline_parent, NULL,
770 fn: vm_unregister_cmdline_device);
771 device_unregister(dev: &vm_cmdline_parent);
772 vm_cmdline_parent_registered = 0;
773 }
774}
775
776#else
777
778static void vm_unregister_cmdline_devices(void)
779{
780}
781
782#endif
783
784/* Platform driver */
785
786static const struct of_device_id virtio_mmio_match[] = {
787 { .compatible = "virtio,mmio", },
788 {},
789};
790MODULE_DEVICE_TABLE(of, virtio_mmio_match);
791
792#ifdef CONFIG_ACPI
793static const struct acpi_device_id virtio_mmio_acpi_match[] = {
794 { "LNRO0005", },
795 { }
796};
797MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
798#endif
799
800static struct platform_driver virtio_mmio_driver = {
801 .probe = virtio_mmio_probe,
802 .remove = virtio_mmio_remove,
803 .driver = {
804 .name = "virtio-mmio",
805 .of_match_table = virtio_mmio_match,
806 .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
807#ifdef CONFIG_PM_SLEEP
808 .pm = &virtio_mmio_pm_ops,
809#endif
810 },
811};
812
813static int __init virtio_mmio_init(void)
814{
815 return platform_driver_register(&virtio_mmio_driver);
816}
817
818static void __exit virtio_mmio_exit(void)
819{
820 platform_driver_unregister(&virtio_mmio_driver);
821 vm_unregister_cmdline_devices();
822}
823
824module_init(virtio_mmio_init);
825module_exit(virtio_mmio_exit);
826
827MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
828MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
829MODULE_LICENSE("GPL");
830

source code of linux/drivers/virtio/virtio_mmio.c