Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * Virtio memory mapped device driver
4 : *
5 : * Copyright 2011-2014, ARM Ltd.
6 : *
7 : * This module allows virtio devices to be used over a virtual, memory mapped
8 : * platform device.
9 : *
10 : * The guest device(s) may be instantiated in one of three equivalent ways:
11 : *
12 : * 1. Static platform device in board's code, eg.:
13 : *
14 : * static struct platform_device v2m_virtio_device = {
15 : * .name = "virtio-mmio",
16 : * .id = -1,
17 : * .num_resources = 2,
18 : * .resource = (struct resource []) {
19 : * {
20 : * .start = 0x1001e000,
21 : * .end = 0x1001e0ff,
22 : * .flags = IORESOURCE_MEM,
23 : * }, {
24 : * .start = 42 + 32,
25 : * .end = 42 + 32,
26 : * .flags = IORESOURCE_IRQ,
27 : * },
28 : * }
29 : * };
30 : *
31 : * 2. Device Tree node, eg.:
32 : *
33 : * virtio_block@1e000 {
34 : * compatible = "virtio,mmio";
35 : * reg = <0x1e000 0x100>;
36 : * interrupts = <42>;
37 : * }
38 : *
39 : * 3. Kernel module (or command line) parameter. Can be used more than once -
40 : * one device will be created for each one. Syntax:
41 : *
42 : * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>]
43 : * where:
44 : * <size> := size (can use standard suffixes like K, M or G)
45 : * <baseaddr> := physical base address
46 : * <irq> := interrupt number (as passed to request_irq())
47 : * <id> := (optional) platform device id
48 : * eg.:
49 : * virtio_mmio.device=0x100@0x100b0000:48 \
50 : * virtio_mmio.device=1K@0x1001e000:74
51 : *
52 : * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
53 : */
54 :
55 : #define pr_fmt(fmt) "virtio-mmio: " fmt
56 :
57 : #include <linux/acpi.h>
58 : #include <linux/dma-mapping.h>
59 : #include <linux/highmem.h>
60 : #include <linux/interrupt.h>
61 : #include <linux/io.h>
62 : #include <linux/list.h>
63 : #include <linux/module.h>
64 : #include <linux/platform_device.h>
65 : #include <linux/slab.h>
66 : #include <linux/spinlock.h>
67 : #include <linux/virtio.h>
68 : #include <linux/virtio_config.h>
69 : #include <uapi/linux/virtio_mmio.h>
70 : #include <linux/virtio_ring.h>
71 :
72 :
73 :
74 : /* The alignment to use between consumer and producer parts of vring.
75 : * Currently hardcoded to the page size. */
76 : #define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
77 :
78 :
79 :
80 : #define to_virtio_mmio_device(_plat_dev) \
81 : container_of(_plat_dev, struct virtio_mmio_device, vdev)
82 :
83 : struct virtio_mmio_device {
84 : struct virtio_device vdev;
85 : struct platform_device *pdev;
86 :
87 : void __iomem *base;
88 : unsigned long version;
89 :
90 : /* a list of queues so we can dispatch IRQs */
91 : spinlock_t lock;
92 : struct list_head virtqueues;
93 : };
94 :
95 : struct virtio_mmio_vq_info {
96 : /* the actual virtqueue */
97 : struct virtqueue *vq;
98 :
99 : /* the list node for the virtqueues list */
100 : struct list_head node;
101 : };
102 :
103 :
104 :
105 : /* Configuration interface */
106 :
107 2 : static u64 vm_get_features(struct virtio_device *vdev)
108 : {
109 2 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
110 2 : u64 features;
111 :
112 2 : writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
113 2 : features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
114 2 : features <<= 32;
115 :
116 2 : writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
117 2 : features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
118 :
119 2 : return features;
120 : }
121 :
122 2 : static int vm_finalize_features(struct virtio_device *vdev)
123 : {
124 2 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
125 :
126 : /* Give virtio_ring a chance to accept features. */
127 2 : vring_transport_features(vdev);
128 :
129 : /* Make sure there are no mixed devices */
130 2 : if (vm_dev->version == 2 &&
131 0 : !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
132 0 : dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
133 0 : return -EINVAL;
134 : }
135 :
136 2 : writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
137 4 : writel((u32)(vdev->features >> 32),
138 2 : vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
139 :
140 2 : writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
141 2 : writel((u32)vdev->features,
142 2 : vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
143 :
144 2 : return 0;
145 : }
146 :
147 19 : static void vm_get(struct virtio_device *vdev, unsigned offset,
148 : void *buf, unsigned len)
149 : {
150 19 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
151 19 : void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
152 19 : u8 b;
153 19 : __le16 w;
154 19 : __le32 l;
155 :
156 19 : if (vm_dev->version == 1) {
157 68 : u8 *ptr = buf;
158 : int i;
159 :
160 68 : for (i = 0; i < len; i++)
161 49 : ptr[i] = readb(base + offset + i);
162 : return;
163 : }
164 :
165 0 : switch (len) {
166 0 : case 1:
167 0 : b = readb(base + offset);
168 0 : memcpy(buf, &b, sizeof b);
169 0 : break;
170 0 : case 2:
171 0 : w = cpu_to_le16(readw(base + offset));
172 0 : memcpy(buf, &w, sizeof w);
173 0 : break;
174 0 : case 4:
175 0 : l = cpu_to_le32(readl(base + offset));
176 0 : memcpy(buf, &l, sizeof l);
177 0 : break;
178 0 : case 8:
179 0 : l = cpu_to_le32(readl(base + offset));
180 0 : memcpy(buf, &l, sizeof l);
181 0 : l = cpu_to_le32(ioread32(base + offset + sizeof l));
182 0 : memcpy(buf + sizeof l, &l, sizeof l);
183 0 : break;
184 0 : default:
185 0 : BUG();
186 : }
187 : }
188 :
189 0 : static void vm_set(struct virtio_device *vdev, unsigned offset,
190 : const void *buf, unsigned len)
191 : {
192 0 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
193 0 : void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG;
194 0 : u8 b;
195 0 : __le16 w;
196 0 : __le32 l;
197 :
198 0 : if (vm_dev->version == 1) {
199 0 : const u8 *ptr = buf;
200 : int i;
201 :
202 0 : for (i = 0; i < len; i++)
203 0 : writeb(ptr[i], base + offset + i);
204 :
205 : return;
206 : }
207 :
208 0 : switch (len) {
209 0 : case 1:
210 0 : memcpy(&b, buf, sizeof b);
211 0 : writeb(b, base + offset);
212 : break;
213 0 : case 2:
214 0 : memcpy(&w, buf, sizeof w);
215 0 : writew(le16_to_cpu(w), base + offset);
216 : break;
217 0 : case 4:
218 0 : memcpy(&l, buf, sizeof l);
219 0 : writel(le32_to_cpu(l), base + offset);
220 : break;
221 0 : case 8:
222 0 : memcpy(&l, buf, sizeof l);
223 0 : writel(le32_to_cpu(l), base + offset);
224 0 : memcpy(&l, buf + sizeof l, sizeof l);
225 0 : writel(le32_to_cpu(l), base + offset + sizeof l);
226 : break;
227 0 : default:
228 0 : BUG();
229 : }
230 : }
231 :
232 4 : static u32 vm_generation(struct virtio_device *vdev)
233 : {
234 4 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
235 :
236 4 : if (vm_dev->version == 1)
237 : return 0;
238 : else
239 0 : return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
240 : }
241 :
242 8 : static u8 vm_get_status(struct virtio_device *vdev)
243 : {
244 8 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
245 :
246 8 : return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
247 : }
248 :
249 6 : static void vm_set_status(struct virtio_device *vdev, u8 status)
250 : {
251 6 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
252 :
253 : /* We should never be setting status to 0. */
254 6 : BUG_ON(status == 0);
255 :
256 6 : writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
257 6 : }
258 :
259 2 : static void vm_reset(struct virtio_device *vdev)
260 : {
261 2 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
262 :
263 : /* 0 status means a reset. */
264 2 : writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
265 2 : }
266 :
267 :
268 :
269 : /* Transport interface */
270 :
271 : /* the notify function used when creating a virt queue */
272 3185 : static bool vm_notify(struct virtqueue *vq)
273 : {
274 3185 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
275 :
276 : /* We write the queue's selector into the notification register to
277 : * signal the other end */
278 3185 : writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
279 3185 : return true;
280 : }
281 :
282 : /* Notify all virtqueues on an interrupt. */
283 3263 : static irqreturn_t vm_interrupt(int irq, void *opaque)
284 : {
285 3263 : struct virtio_mmio_device *vm_dev = opaque;
286 3263 : struct virtio_mmio_vq_info *info;
287 3263 : unsigned long status;
288 3263 : unsigned long flags;
289 3263 : irqreturn_t ret = IRQ_NONE;
290 :
291 : /* Read and acknowledge interrupts */
292 3263 : status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
293 3263 : writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
294 :
295 3263 : if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
296 0 : virtio_config_changed(&vm_dev->vdev);
297 0 : ret = IRQ_HANDLED;
298 : }
299 :
300 3263 : if (likely(status & VIRTIO_MMIO_INT_VRING)) {
301 3157 : spin_lock_irqsave(&vm_dev->lock, flags);
302 7284 : list_for_each_entry(info, &vm_dev->virtqueues, node)
303 4127 : ret |= vring_interrupt(irq, info->vq);
304 3157 : spin_unlock_irqrestore(&vm_dev->lock, flags);
305 : }
306 :
307 3263 : return ret;
308 : }
309 :
310 :
311 :
312 0 : static void vm_del_vq(struct virtqueue *vq)
313 : {
314 0 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
315 0 : struct virtio_mmio_vq_info *info = vq->priv;
316 0 : unsigned long flags;
317 0 : unsigned int index = vq->index;
318 :
319 0 : spin_lock_irqsave(&vm_dev->lock, flags);
320 0 : list_del(&info->node);
321 0 : spin_unlock_irqrestore(&vm_dev->lock, flags);
322 :
323 : /* Select and deactivate the queue */
324 0 : writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
325 0 : if (vm_dev->version == 1) {
326 0 : writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
327 : } else {
328 0 : writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
329 0 : WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
330 : }
331 :
332 0 : vring_del_virtqueue(vq);
333 :
334 0 : kfree(info);
335 0 : }
336 :
337 0 : static void vm_del_vqs(struct virtio_device *vdev)
338 : {
339 0 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
340 0 : struct virtqueue *vq, *n;
341 :
342 0 : list_for_each_entry_safe(vq, n, &vdev->vqs, list)
343 0 : vm_del_vq(vq);
344 :
345 0 : free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
346 0 : }
347 :
348 4 : static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
349 : void (*callback)(struct virtqueue *vq),
350 : const char *name, bool ctx)
351 : {
352 4 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
353 4 : struct virtio_mmio_vq_info *info;
354 4 : struct virtqueue *vq;
355 4 : unsigned long flags;
356 4 : unsigned int num;
357 4 : int err;
358 :
359 4 : if (!name)
360 : return NULL;
361 :
362 : /* Select the queue we're interested in */
363 4 : writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
364 :
365 : /* Queue shouldn't already be set up. */
366 4 : if (readl(vm_dev->base + (vm_dev->version == 1 ?
367 4 : VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
368 0 : err = -ENOENT;
369 0 : goto error_available;
370 : }
371 :
372 : /* Allocate and fill out our active queue description */
373 4 : info = kmalloc(sizeof(*info), GFP_KERNEL);
374 4 : if (!info) {
375 0 : err = -ENOMEM;
376 0 : goto error_kmalloc;
377 : }
378 :
379 4 : num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
380 4 : if (num == 0) {
381 0 : err = -ENOENT;
382 0 : goto error_new_virtqueue;
383 : }
384 :
385 : /* Create the vring */
386 4 : vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev,
387 : true, true, ctx, vm_notify, callback, name);
388 4 : if (!vq) {
389 0 : err = -ENOMEM;
390 0 : goto error_new_virtqueue;
391 : }
392 :
393 : /* Activate the queue */
394 4 : writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
395 4 : if (vm_dev->version == 1) {
396 4 : u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
397 :
398 : /*
399 : * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
400 : * that doesn't fit in 32bit, fail the setup rather than
401 : * pretending to be successful.
402 : */
403 4 : if (q_pfn >> 32) {
404 0 : dev_err(&vdev->dev,
405 : "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
406 : 0x1ULL << (32 + PAGE_SHIFT - 30));
407 0 : err = -E2BIG;
408 0 : goto error_bad_pfn;
409 : }
410 :
411 4 : writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
412 4 : writel(q_pfn, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
413 : } else {
414 0 : u64 addr;
415 :
416 0 : addr = virtqueue_get_desc_addr(vq);
417 0 : writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
418 0 : writel((u32)(addr >> 32),
419 0 : vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
420 :
421 0 : addr = virtqueue_get_avail_addr(vq);
422 0 : writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
423 0 : writel((u32)(addr >> 32),
424 0 : vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
425 :
426 0 : addr = virtqueue_get_used_addr(vq);
427 0 : writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
428 0 : writel((u32)(addr >> 32),
429 0 : vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
430 :
431 0 : writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
432 : }
433 :
434 4 : vq->priv = info;
435 4 : info->vq = vq;
436 :
437 4 : spin_lock_irqsave(&vm_dev->lock, flags);
438 4 : list_add(&info->node, &vm_dev->virtqueues);
439 4 : spin_unlock_irqrestore(&vm_dev->lock, flags);
440 :
441 4 : return vq;
442 :
443 0 : error_bad_pfn:
444 0 : vring_del_virtqueue(vq);
445 0 : error_new_virtqueue:
446 0 : if (vm_dev->version == 1) {
447 0 : writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
448 : } else {
449 0 : writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
450 0 : WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
451 : }
452 0 : kfree(info);
453 0 : error_kmalloc:
454 0 : error_available:
455 0 : return ERR_PTR(err);
456 : }
457 :
458 2 : static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
459 : struct virtqueue *vqs[],
460 : vq_callback_t *callbacks[],
461 : const char * const names[],
462 : const bool *ctx,
463 : struct irq_affinity *desc)
464 : {
465 2 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
466 2 : int irq = platform_get_irq(vm_dev->pdev, 0);
467 2 : int i, err, queue_idx = 0;
468 :
469 2 : if (irq < 0)
470 : return irq;
471 :
472 2 : err = request_irq(irq, vm_interrupt, IRQF_SHARED,
473 2 : dev_name(&vdev->dev), vm_dev);
474 2 : if (err)
475 : return err;
476 :
477 6 : for (i = 0; i < nvqs; ++i) {
478 4 : if (!names[i]) {
479 0 : vqs[i] = NULL;
480 0 : continue;
481 : }
482 :
483 4 : vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
484 4 : ctx ? ctx[i] : false);
485 4 : if (IS_ERR(vqs[i])) {
486 0 : vm_del_vqs(vdev);
487 0 : return PTR_ERR(vqs[i]);
488 : }
489 : }
490 :
491 : return 0;
492 : }
493 :
494 1 : static const char *vm_bus_name(struct virtio_device *vdev)
495 : {
496 1 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
497 :
498 1 : return vm_dev->pdev->name;
499 : }
500 :
501 0 : static bool vm_get_shm_region(struct virtio_device *vdev,
502 : struct virtio_shm_region *region, u8 id)
503 : {
504 0 : struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
505 0 : u64 len, addr;
506 :
507 : /* Select the region we're interested in */
508 0 : writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
509 :
510 : /* Read the region size */
511 0 : len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
512 0 : len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
513 :
514 0 : region->len = len;
515 :
516 : /* Check if region length is -1. If that's the case, the shared memory
517 : * region does not exist and there is no need to proceed further.
518 : */
519 0 : if (len == ~(u64)0)
520 : return false;
521 :
522 : /* Read the region base address */
523 0 : addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
524 0 : addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
525 :
526 0 : region->addr = addr;
527 :
528 0 : return true;
529 : }
530 :
531 : static const struct virtio_config_ops virtio_mmio_config_ops = {
532 : .get = vm_get,
533 : .set = vm_set,
534 : .generation = vm_generation,
535 : .get_status = vm_get_status,
536 : .set_status = vm_set_status,
537 : .reset = vm_reset,
538 : .find_vqs = vm_find_vqs,
539 : .del_vqs = vm_del_vqs,
540 : .get_features = vm_get_features,
541 : .finalize_features = vm_finalize_features,
542 : .bus_name = vm_bus_name,
543 : .get_shm_region = vm_get_shm_region,
544 : };
545 :
546 :
547 0 : static void virtio_mmio_release_dev(struct device *_d)
548 : {
549 0 : struct virtio_device *vdev =
550 0 : container_of(_d, struct virtio_device, dev);
551 0 : struct virtio_mmio_device *vm_dev =
552 0 : container_of(vdev, struct virtio_mmio_device, vdev);
553 0 : struct platform_device *pdev = vm_dev->pdev;
554 :
555 0 : devm_kfree(&pdev->dev, vm_dev);
556 0 : }
557 :
558 : /* Platform device */
559 :
560 2 : static int virtio_mmio_probe(struct platform_device *pdev)
561 : {
562 2 : struct virtio_mmio_device *vm_dev;
563 2 : unsigned long magic;
564 2 : int rc;
565 :
566 2 : vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
567 2 : if (!vm_dev)
568 : return -ENOMEM;
569 :
570 2 : vm_dev->vdev.dev.parent = &pdev->dev;
571 2 : vm_dev->vdev.dev.release = virtio_mmio_release_dev;
572 2 : vm_dev->vdev.config = &virtio_mmio_config_ops;
573 2 : vm_dev->pdev = pdev;
574 2 : INIT_LIST_HEAD(&vm_dev->virtqueues);
575 2 : spin_lock_init(&vm_dev->lock);
576 :
577 2 : vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
578 2 : if (IS_ERR(vm_dev->base))
579 0 : return PTR_ERR(vm_dev->base);
580 :
581 : /* Check magic value */
582 2 : magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
583 2 : if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
584 0 : dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
585 0 : return -ENODEV;
586 : }
587 :
588 : /* Check device version */
589 2 : vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
590 2 : if (vm_dev->version < 1 || vm_dev->version > 2) {
591 0 : dev_err(&pdev->dev, "Version %ld not supported!\n",
592 : vm_dev->version);
593 0 : return -ENXIO;
594 : }
595 :
596 2 : vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
597 2 : if (vm_dev->vdev.id.device == 0) {
598 : /*
599 : * virtio-mmio device with an ID 0 is a (dummy) placeholder
600 : * with no function. End probing now with no error reported.
601 : */
602 : return -ENODEV;
603 : }
604 2 : vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
605 :
606 2 : if (vm_dev->version == 1) {
607 2 : writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
608 :
609 2 : rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
610 : /*
611 : * In the legacy case, ensure our coherently-allocated virtio
612 : * ring will be at an address expressable as a 32-bit PFN.
613 : */
614 2 : if (!rc)
615 2 : dma_set_coherent_mask(&pdev->dev,
616 : DMA_BIT_MASK(32 + PAGE_SHIFT));
617 : } else {
618 0 : rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
619 : }
620 2 : if (rc)
621 0 : rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
622 2 : if (rc)
623 0 : dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
624 :
625 2 : platform_set_drvdata(pdev, vm_dev);
626 :
627 2 : rc = register_virtio_device(&vm_dev->vdev);
628 2 : if (rc)
629 0 : put_device(&vm_dev->vdev.dev);
630 :
631 : return rc;
632 : }
633 :
634 0 : static int virtio_mmio_remove(struct platform_device *pdev)
635 : {
636 0 : struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
637 0 : unregister_virtio_device(&vm_dev->vdev);
638 :
639 0 : return 0;
640 : }
641 :
642 :
643 :
644 : /* Devices list parameter */
645 :
646 : #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
647 :
648 : static struct device vm_cmdline_parent = {
649 : .init_name = "virtio-mmio-cmdline",
650 : };
651 :
652 : static int vm_cmdline_parent_registered;
653 : static int vm_cmdline_id;
654 :
655 2 : static int vm_cmdline_set(const char *device,
656 : const struct kernel_param *kp)
657 : {
658 2 : int err;
659 2 : struct resource resources[2] = {};
660 2 : char *str;
661 2 : long long int base, size;
662 2 : unsigned int irq;
663 2 : int processed, consumed = 0;
664 2 : struct platform_device *pdev;
665 :
666 : /* Consume "size" part of the command line parameter */
667 2 : size = memparse(device, &str);
668 :
669 : /* Get "@<base>:<irq>[:<id>]" chunks */
670 2 : processed = sscanf(str, "@%lli:%u%n:%d%n",
671 : &base, &irq, &consumed,
672 : &vm_cmdline_id, &consumed);
673 :
674 : /*
675 : * sscanf() must process at least 2 chunks; also there
676 : * must be no extra characters after the last chunk, so
677 : * str[consumed] must be '\0'
678 : */
679 2 : if (processed < 2 || str[consumed] || irq == 0)
680 : return -EINVAL;
681 :
682 2 : resources[0].flags = IORESOURCE_MEM;
683 2 : resources[0].start = base;
684 2 : resources[0].end = base + size - 1;
685 :
686 2 : resources[1].flags = IORESOURCE_IRQ;
687 2 : resources[1].start = resources[1].end = irq;
688 :
689 2 : if (!vm_cmdline_parent_registered) {
690 1 : err = device_register(&vm_cmdline_parent);
691 1 : if (err) {
692 0 : pr_err("Failed to register parent device!\n");
693 0 : return err;
694 : }
695 1 : vm_cmdline_parent_registered = 1;
696 : }
697 :
698 2 : pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
699 : vm_cmdline_id,
700 : (unsigned long long)resources[0].start,
701 : (unsigned long long)resources[0].end,
702 : (int)resources[1].start);
703 :
704 2 : pdev = platform_device_register_resndata(&vm_cmdline_parent,
705 : "virtio-mmio", vm_cmdline_id++,
706 : resources, ARRAY_SIZE(resources), NULL, 0);
707 :
708 2 : return PTR_ERR_OR_ZERO(pdev);
709 : }
710 :
711 0 : static int vm_cmdline_get_device(struct device *dev, void *data)
712 : {
713 0 : char *buffer = data;
714 0 : unsigned int len = strlen(buffer);
715 0 : struct platform_device *pdev = to_platform_device(dev);
716 :
717 0 : snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
718 0 : pdev->resource[0].end - pdev->resource[0].start + 1ULL,
719 0 : (unsigned long long)pdev->resource[0].start,
720 0 : (unsigned long long)pdev->resource[1].start,
721 : pdev->id);
722 0 : return 0;
723 : }
724 :
725 0 : static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
726 : {
727 0 : buffer[0] = '\0';
728 0 : device_for_each_child(&vm_cmdline_parent, buffer,
729 : vm_cmdline_get_device);
730 0 : return strlen(buffer) + 1;
731 : }
732 :
733 : static const struct kernel_param_ops vm_cmdline_param_ops = {
734 : .set = vm_cmdline_set,
735 : .get = vm_cmdline_get,
736 : };
737 :
738 : device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
739 :
740 0 : static int vm_unregister_cmdline_device(struct device *dev,
741 : void *data)
742 : {
743 0 : platform_device_unregister(to_platform_device(dev));
744 :
745 0 : return 0;
746 : }
747 :
748 0 : static void vm_unregister_cmdline_devices(void)
749 : {
750 0 : if (vm_cmdline_parent_registered) {
751 0 : device_for_each_child(&vm_cmdline_parent, NULL,
752 : vm_unregister_cmdline_device);
753 0 : device_unregister(&vm_cmdline_parent);
754 0 : vm_cmdline_parent_registered = 0;
755 : }
756 0 : }
757 :
758 : #else
759 :
760 : static void vm_unregister_cmdline_devices(void)
761 : {
762 : }
763 :
764 : #endif
765 :
766 : /* Platform driver */
767 :
768 : static const struct of_device_id virtio_mmio_match[] = {
769 : { .compatible = "virtio,mmio", },
770 : {},
771 : };
772 : MODULE_DEVICE_TABLE(of, virtio_mmio_match);
773 :
774 : #ifdef CONFIG_ACPI
775 : static const struct acpi_device_id virtio_mmio_acpi_match[] = {
776 : { "LNRO0005", },
777 : { }
778 : };
779 : MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match);
780 : #endif
781 :
782 : static struct platform_driver virtio_mmio_driver = {
783 : .probe = virtio_mmio_probe,
784 : .remove = virtio_mmio_remove,
785 : .driver = {
786 : .name = "virtio-mmio",
787 : .of_match_table = virtio_mmio_match,
788 : .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
789 : },
790 : };
791 :
792 1 : static int __init virtio_mmio_init(void)
793 : {
794 1 : return platform_driver_register(&virtio_mmio_driver);
795 : }
796 :
797 0 : static void __exit virtio_mmio_exit(void)
798 : {
799 0 : platform_driver_unregister(&virtio_mmio_driver);
800 0 : vm_unregister_cmdline_devices();
801 0 : }
802 :
803 : module_init(virtio_mmio_init);
804 : module_exit(virtio_mmio_exit);
805 :
806 : MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
807 : MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
808 : MODULE_LICENSE("GPL");
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