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Kirkwood: Enable PCIe port 1 on QNAP TS-11x/TS-21x
[linux-2.6.git] / drivers / virtio / virtio_mmio.c
blob1ba0d683101525b1615cc03beea3524f42318694
1 /*
2 * Virtio memory mapped device driver
3 *
4 * Copyright 2011, 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 * Registers layout (all 32-bit wide):
54 *
55 * offset d. name description
56 * ------ -- ---------------- -----------------
57 *
58 * 0x000 R MagicValue Magic value "virt"
59 * 0x004 R Version Device version (current max. 1)
60 * 0x008 R DeviceID Virtio device ID
61 * 0x00c R VendorID Virtio vendor ID
62 *
63 * 0x010 R HostFeatures Features supported by the host
64 * 0x014 W HostFeaturesSel Set of host features to access via HostFeatures
65 *
66 * 0x020 W GuestFeatures Features activated by the guest
67 * 0x024 W GuestFeaturesSel Set of activated features to set via GuestFeatures
68 * 0x028 W GuestPageSize Size of guest's memory page in bytes
69 *
70 * 0x030 W QueueSel Queue selector
71 * 0x034 R QueueNumMax Maximum size of the currently selected queue
72 * 0x038 W QueueNum Queue size for the currently selected queue
73 * 0x03c W QueueAlign Used Ring alignment for the current queue
74 * 0x040 RW QueuePFN PFN for the currently selected queue
75 *
76 * 0x050 W QueueNotify Queue notifier
77 * 0x060 R InterruptStatus Interrupt status register
78 * 0x064 W InterruptACK Interrupt acknowledge register
79 * 0x070 RW Status Device status register
80 *
81 * 0x100+ RW Device-specific configuration space
82 *
83 * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
84 *
85 * This work is licensed under the terms of the GNU GPL, version 2 or later.
86 * See the COPYING file in the top-level directory.
87 */
88
89 #define pr_fmt(fmt) "virtio-mmio: " fmt
90
91 #include <linux/highmem.h>
92 #include <linux/interrupt.h>
93 #include <linux/io.h>
94 #include <linux/list.h>
95 #include <linux/module.h>
96 #include <linux/platform_device.h>
97 #include <linux/slab.h>
98 #include <linux/spinlock.h>
99 #include <linux/virtio.h>
100 #include <linux/virtio_config.h>
101 #include <linux/virtio_mmio.h>
102 #include <linux/virtio_ring.h>
103
104
105
106 /* The alignment to use between consumer and producer parts of vring.
107 * Currently hardcoded to the page size. */
108 #define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
109
110
111
112 #define to_virtio_mmio_device(_plat_dev) \
113 container_of(_plat_dev, struct virtio_mmio_device, vdev)
114
115 struct virtio_mmio_device {
116 struct virtio_device vdev;
117 struct platform_device *pdev;
118
119 void __iomem *base;
120 unsigned long version;
121
122 /* a list of queues so we can dispatch IRQs */
123 spinlock_t lock;
124 struct list_head virtqueues;
125 };
126
127 struct virtio_mmio_vq_info {
128 /* the actual virtqueue */
129 struct virtqueue *vq;
130
131 /* the number of entries in the queue */
132 unsigned int num;
133
134 /* the virtual address of the ring queue */
135 void *queue;
136
137 /* the list node for the virtqueues list */
138 struct list_head node;
139 };
140
141
142
143 /* Configuration interface */
144
145 static u32 vm_get_features(struct virtio_device *vdev)
146 {
147 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
148
149 /* TODO: Features > 32 bits */
150 writel(0, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
151
152 return readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
153 }
154
155 static void vm_finalize_features(struct virtio_device *vdev)
156 {
157 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
158 int i;
159
160 /* Give virtio_ring a chance to accept features. */
161 vring_transport_features(vdev);
162
163 for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
164 writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
165 writel(vdev->features[i],
166 vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
167 }
168 }
169
170 static void vm_get(struct virtio_device *vdev, unsigned offset,
171 void *buf, unsigned len)
172 {
173 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
174 u8 *ptr = buf;
175 int i;
176
177 for (i = 0; i < len; i++)
178 ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
179 }
180
181 static void vm_set(struct virtio_device *vdev, unsigned offset,
182 const void *buf, unsigned len)
183 {
184 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
185 const u8 *ptr = buf;
186 int i;
187
188 for (i = 0; i < len; i++)
189 writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
190 }
191
192 static u8 vm_get_status(struct virtio_device *vdev)
193 {
194 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
195
196 return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
197 }
198
199 static void vm_set_status(struct virtio_device *vdev, u8 status)
200 {
201 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
202
203 /* We should never be setting status to 0. */
204 BUG_ON(status == 0);
205
206 writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
207 }
208
209 static void vm_reset(struct virtio_device *vdev)
210 {
211 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
212
213 /* 0 status means a reset. */
214 writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
215 }
216
217
218
219 /* Transport interface */
220
221 /* the notify function used when creating a virt queue */
222 static void vm_notify(struct virtqueue *vq)
223 {
224 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
225
226 /* We write the queue's selector into the notification register to
227 * signal the other end */
228 writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
229 }
230
231 /* Notify all virtqueues on an interrupt. */
232 static irqreturn_t vm_interrupt(int irq, void *opaque)
233 {
234 struct virtio_mmio_device *vm_dev = opaque;
235 struct virtio_mmio_vq_info *info;
236 struct virtio_driver *vdrv = container_of(vm_dev->vdev.dev.driver,
237 struct virtio_driver, driver);
238 unsigned long status;
239 unsigned long flags;
240 irqreturn_t ret = IRQ_NONE;
241
242 /* Read and acknowledge interrupts */
243 status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
244 writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
245
246 if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
247 && vdrv && vdrv->config_changed) {
248 vdrv->config_changed(&vm_dev->vdev);
249 ret = IRQ_HANDLED;
250 }
251
252 if (likely(status & VIRTIO_MMIO_INT_VRING)) {
253 spin_lock_irqsave(&vm_dev->lock, flags);
254 list_for_each_entry(info, &vm_dev->virtqueues, node)
255 ret |= vring_interrupt(irq, info->vq);
256 spin_unlock_irqrestore(&vm_dev->lock, flags);
257 }
258
259 return ret;
260 }
261
262
263
264 static void vm_del_vq(struct virtqueue *vq)
265 {
266 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
267 struct virtio_mmio_vq_info *info = vq->priv;
268 unsigned long flags, size;
269 unsigned int index = vq->index;
270
271 spin_lock_irqsave(&vm_dev->lock, flags);
272 list_del(&info->node);
273 spin_unlock_irqrestore(&vm_dev->lock, flags);
274
275 vring_del_virtqueue(vq);
276
277 /* Select and deactivate the queue */
278 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
279 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
280
281 size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));
282 free_pages_exact(info->queue, size);
283 kfree(info);
284 }
285
286 static void vm_del_vqs(struct virtio_device *vdev)
287 {
288 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
289 struct virtqueue *vq, *n;
290
291 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
292 vm_del_vq(vq);
293
294 free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
295 }
296
297
298
299 static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
300 void (*callback)(struct virtqueue *vq),
301 const char *name)
302 {
303 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
304 struct virtio_mmio_vq_info *info;
305 struct virtqueue *vq;
306 unsigned long flags, size;
307 int err;
308
309 if (!name)
310 return NULL;
311
312 /* Select the queue we're interested in */
313 writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
314
315 /* Queue shouldn't already be set up. */
316 if (readl(vm_dev->base + VIRTIO_MMIO_QUEUE_PFN)) {
317 err = -ENOENT;
318 goto error_available;
319 }
320
321 /* Allocate and fill out our active queue description */
322 info = kmalloc(sizeof(*info), GFP_KERNEL);
323 if (!info) {
324 err = -ENOMEM;
325 goto error_kmalloc;
326 }
327
328 /* Allocate pages for the queue - start with a queue as big as
329 * possible (limited by maximum size allowed by device), drop down
330 * to a minimal size, just big enough to fit descriptor table
331 * and two rings (which makes it "alignment_size * 2")
332 */
333 info->num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
334
335 /* If the device reports a 0 entry queue, we won't be able to
336 * use it to perform I/O, and vring_new_virtqueue() can't create
337 * empty queues anyway, so don't bother to set up the device.
338 */
339 if (info->num == 0) {
340 err = -ENOENT;
341 goto error_alloc_pages;
342 }
343
344 while (1) {
345 size = PAGE_ALIGN(vring_size(info->num,
346 VIRTIO_MMIO_VRING_ALIGN));
347 /* Did the last iter shrink the queue below minimum size? */
348 if (size < VIRTIO_MMIO_VRING_ALIGN * 2) {
349 err = -ENOMEM;
350 goto error_alloc_pages;
351 }
352
353 info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
354 if (info->queue)
355 break;
356
357 info->num /= 2;
358 }
359
360 /* Activate the queue */
361 writel(info->num, vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
362 writel(VIRTIO_MMIO_VRING_ALIGN,
363 vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
364 writel(virt_to_phys(info->queue) >> PAGE_SHIFT,
365 vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
366
367 /* Create the vring */
368 vq = vring_new_virtqueue(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev,
369 true, info->queue, vm_notify, callback, name);
370 if (!vq) {
371 err = -ENOMEM;
372 goto error_new_virtqueue;
373 }
374
375 vq->priv = info;
376 info->vq = vq;
377
378 spin_lock_irqsave(&vm_dev->lock, flags);
379 list_add(&info->node, &vm_dev->virtqueues);
380 spin_unlock_irqrestore(&vm_dev->lock, flags);
381
382 return vq;
383
384 error_new_virtqueue:
385 writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
386 free_pages_exact(info->queue, size);
387 error_alloc_pages:
388 kfree(info);
389 error_kmalloc:
390 error_available:
391 return ERR_PTR(err);
392 }
393
394 static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
395 struct virtqueue *vqs[],
396 vq_callback_t *callbacks[],
397 const char *names[])
398 {
399 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
400 unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
401 int i, err;
402
403 err = request_irq(irq, vm_interrupt, IRQF_SHARED,
404 dev_name(&vdev->dev), vm_dev);
405 if (err)
406 return err;
407
408 for (i = 0; i < nvqs; ++i) {
409 vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i]);
410 if (IS_ERR(vqs[i])) {
411 vm_del_vqs(vdev);
412 return PTR_ERR(vqs[i]);
413 }
414 }
415
416 return 0;
417 }
418
419 static const char *vm_bus_name(struct virtio_device *vdev)
420 {
421 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
422
423 return vm_dev->pdev->name;
424 }
425
426 static const struct virtio_config_ops virtio_mmio_config_ops = {
427 .get = vm_get,
428 .set = vm_set,
429 .get_status = vm_get_status,
430 .set_status = vm_set_status,
431 .reset = vm_reset,
432 .find_vqs = vm_find_vqs,
433 .del_vqs = vm_del_vqs,
434 .get_features = vm_get_features,
435 .finalize_features = vm_finalize_features,
436 .bus_name = vm_bus_name,
437 };
438
439
440
441 /* Platform device */
442
443 static int virtio_mmio_probe(struct platform_device *pdev)
444 {
445 struct virtio_mmio_device *vm_dev;
446 struct resource *mem;
447 unsigned long magic;
448
449 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
450 if (!mem)
451 return -EINVAL;
452
453 if (!devm_request_mem_region(&pdev->dev, mem->start,
454 resource_size(mem), pdev->name))
455 return -EBUSY;
456
457 vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
458 if (!vm_dev)
459 return -ENOMEM;
460
461 vm_dev->vdev.dev.parent = &pdev->dev;
462 vm_dev->vdev.config = &virtio_mmio_config_ops;
463 vm_dev->pdev = pdev;
464 INIT_LIST_HEAD(&vm_dev->virtqueues);
465 spin_lock_init(&vm_dev->lock);
466
467 vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
468 if (vm_dev->base == NULL)
469 return -EFAULT;
470
471 /* Check magic value */
472 magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
473 if (memcmp(&magic, "virt", 4) != 0) {
474 dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
475 return -ENODEV;
476 }
477
478 /* Check device version */
479 vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
480 if (vm_dev->version != 1) {
481 dev_err(&pdev->dev, "Version %ld not supported!\n",
482 vm_dev->version);
483 return -ENXIO;
484 }
485
486 vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
487 vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
488
489 writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
490
491 platform_set_drvdata(pdev, vm_dev);
492
493 return register_virtio_device(&vm_dev->vdev);
494 }
495
496 static int virtio_mmio_remove(struct platform_device *pdev)
497 {
498 struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
499
500 unregister_virtio_device(&vm_dev->vdev);
501
502 return 0;
503 }
504
505
506
507 /* Devices list parameter */
508
509 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
510
511 static struct device vm_cmdline_parent = {
512 .init_name = "virtio-mmio-cmdline",
513 };
514
515 static int vm_cmdline_parent_registered;
516 static int vm_cmdline_id;
517
518 static int vm_cmdline_set(const char *device,
519 const struct kernel_param *kp)
520 {
521 int err;
522 struct resource resources[2] = {};
523 char *str;
524 long long int base, size;
525 unsigned int irq;
526 int processed, consumed = 0;
527 struct platform_device *pdev;
528
529 /* Consume "size" part of the command line parameter */
530 size = memparse(device, &str);
531
532 /* Get "@<base>:<irq>[:<id>]" chunks */
533 processed = sscanf(str, "@%lli:%u%n:%d%n",
534 &base, &irq, &consumed,
535 &vm_cmdline_id, &consumed);
536
537 /*
538 * sscanf() must processes at least 2 chunks; also there
539 * must be no extra characters after the last chunk, so
540 * str[consumed] must be '\0'
541 */
542 if (processed < 2 || str[consumed])
543 return -EINVAL;
544
545 resources[0].flags = IORESOURCE_MEM;
546 resources[0].start = base;
547 resources[0].end = base + size - 1;
548
549 resources[1].flags = IORESOURCE_IRQ;
550 resources[1].start = resources[1].end = irq;
551
552 if (!vm_cmdline_parent_registered) {
553 err = device_register(&vm_cmdline_parent);
554 if (err) {
555 pr_err("Failed to register parent device!\n");
556 return err;
557 }
558 vm_cmdline_parent_registered = 1;
559 }
560
561 pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
562 vm_cmdline_id,
563 (unsigned long long)resources[0].start,
564 (unsigned long long)resources[0].end,
565 (int)resources[1].start);
566
567 pdev = platform_device_register_resndata(&vm_cmdline_parent,
568 "virtio-mmio", vm_cmdline_id++,
569 resources, ARRAY_SIZE(resources), NULL, 0);
570 if (IS_ERR(pdev))
571 return PTR_ERR(pdev);
572
573 return 0;
574 }
575
576 static int vm_cmdline_get_device(struct device *dev, void *data)
577 {
578 char *buffer = data;
579 unsigned int len = strlen(buffer);
580 struct platform_device *pdev = to_platform_device(dev);
581
582 snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
583 pdev->resource[0].end - pdev->resource[0].start + 1ULL,
584 (unsigned long long)pdev->resource[0].start,
585 (unsigned long long)pdev->resource[1].start,
586 pdev->id);
587 return 0;
588 }
589
590 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
591 {
592 buffer[0] = '\0';
593 device_for_each_child(&vm_cmdline_parent, buffer,
594 vm_cmdline_get_device);
595 return strlen(buffer) + 1;
596 }
597
598 static struct kernel_param_ops vm_cmdline_param_ops = {
599 .set = vm_cmdline_set,
600 .get = vm_cmdline_get,
601 };
602
603 device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
604
605 static int vm_unregister_cmdline_device(struct device *dev,
606 void *data)
607 {
608 platform_device_unregister(to_platform_device(dev));
609
610 return 0;
611 }
612
613 static void vm_unregister_cmdline_devices(void)
614 {
615 if (vm_cmdline_parent_registered) {
616 device_for_each_child(&vm_cmdline_parent, NULL,
617 vm_unregister_cmdline_device);
618 device_unregister(&vm_cmdline_parent);
619 vm_cmdline_parent_registered = 0;
620 }
621 }
622
623 #else
624
625 static void vm_unregister_cmdline_devices(void)
626 {
627 }
628
629 #endif
630
631 /* Platform driver */
632
633 static struct of_device_id virtio_mmio_match[] = {
634 { .compatible = "virtio,mmio", },
635 {},
636 };
637 MODULE_DEVICE_TABLE(of, virtio_mmio_match);
638
639 static struct platform_driver virtio_mmio_driver = {
640 .probe = virtio_mmio_probe,
641 .remove = virtio_mmio_remove,
642 .driver = {
643 .name = "virtio-mmio",
644 .owner = THIS_MODULE,
645 .of_match_table = virtio_mmio_match,
646 },
647 };
648
649 static int __init virtio_mmio_init(void)
650 {
651 return platform_driver_register(&virtio_mmio_driver);
652 }
653
654 static void __exit virtio_mmio_exit(void)
655 {
656 platform_driver_unregister(&virtio_mmio_driver);
657 vm_unregister_cmdline_devices();
658 }
659
660 module_init(virtio_mmio_init);
661 module_exit(virtio_mmio_exit);
662
663 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
664 MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
665 MODULE_LICENSE("GPL");
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