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/spinlock.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 | /* a list of queues so we can dispatch IRQs */ |
93 | spinlock_t lock; |
94 | struct list_head virtqueues; |
95 | }; |
96 | |
97 | struct virtio_mmio_vq_info { |
98 | /* the actual virtqueue */ |
99 | struct virtqueue *vq; |
100 | |
101 | /* the list node for the virtqueues list */ |
102 | struct list_head node; |
103 | }; |
104 | |
105 | |
106 | |
107 | /* Configuration interface */ |
108 | |
109 | static u64 vm_get_features(struct virtio_device *vdev) |
110 | { |
111 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
112 | u64 features; |
113 | |
114 | writel(val: 1, addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); |
115 | features = readl(addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); |
116 | features <<= 32; |
117 | |
118 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL); |
119 | features |= readl(addr: vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES); |
120 | |
121 | return features; |
122 | } |
123 | |
124 | static int vm_finalize_features(struct virtio_device *vdev) |
125 | { |
126 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
127 | |
128 | /* Give virtio_ring a chance to accept features. */ |
129 | vring_transport_features(vdev); |
130 | |
131 | /* Make sure there are no mixed devices */ |
132 | if (vm_dev->version == 2 && |
133 | !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) { |
134 | dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n" ); |
135 | return -EINVAL; |
136 | } |
137 | |
138 | writel(val: 1, addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); |
139 | writel(val: (u32)(vdev->features >> 32), |
140 | addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); |
141 | |
142 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL); |
143 | writel(val: (u32)vdev->features, |
144 | addr: vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES); |
145 | |
146 | return 0; |
147 | } |
148 | |
149 | static void vm_get(struct virtio_device *vdev, unsigned int offset, |
150 | void *buf, unsigned int len) |
151 | { |
152 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
153 | void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; |
154 | u8 b; |
155 | __le16 w; |
156 | __le32 l; |
157 | |
158 | if (vm_dev->version == 1) { |
159 | u8 *ptr = buf; |
160 | int i; |
161 | |
162 | for (i = 0; i < len; i++) |
163 | ptr[i] = readb(addr: base + offset + i); |
164 | return; |
165 | } |
166 | |
167 | switch (len) { |
168 | case 1: |
169 | b = readb(addr: base + offset); |
170 | memcpy(buf, &b, sizeof b); |
171 | break; |
172 | case 2: |
173 | w = cpu_to_le16(readw(base + offset)); |
174 | memcpy(buf, &w, sizeof w); |
175 | break; |
176 | case 4: |
177 | l = cpu_to_le32(readl(base + offset)); |
178 | memcpy(buf, &l, sizeof l); |
179 | break; |
180 | case 8: |
181 | l = cpu_to_le32(readl(base + offset)); |
182 | memcpy(buf, &l, sizeof l); |
183 | l = cpu_to_le32(ioread32(base + offset + sizeof l)); |
184 | memcpy(buf + sizeof l, &l, sizeof l); |
185 | break; |
186 | default: |
187 | BUG(); |
188 | } |
189 | } |
190 | |
191 | static void vm_set(struct virtio_device *vdev, unsigned int offset, |
192 | const void *buf, unsigned int len) |
193 | { |
194 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
195 | void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; |
196 | u8 b; |
197 | __le16 w; |
198 | __le32 l; |
199 | |
200 | if (vm_dev->version == 1) { |
201 | const u8 *ptr = buf; |
202 | int i; |
203 | |
204 | for (i = 0; i < len; i++) |
205 | writeb(val: ptr[i], addr: base + offset + i); |
206 | |
207 | return; |
208 | } |
209 | |
210 | switch (len) { |
211 | case 1: |
212 | memcpy(&b, buf, sizeof b); |
213 | writeb(val: b, addr: base + offset); |
214 | break; |
215 | case 2: |
216 | memcpy(&w, buf, sizeof w); |
217 | writew(le16_to_cpu(w), addr: base + offset); |
218 | break; |
219 | case 4: |
220 | memcpy(&l, buf, sizeof l); |
221 | writel(le32_to_cpu(l), addr: base + offset); |
222 | break; |
223 | case 8: |
224 | memcpy(&l, buf, sizeof l); |
225 | writel(le32_to_cpu(l), addr: base + offset); |
226 | memcpy(&l, buf + sizeof l, sizeof l); |
227 | writel(le32_to_cpu(l), addr: base + offset + sizeof l); |
228 | break; |
229 | default: |
230 | BUG(); |
231 | } |
232 | } |
233 | |
234 | static u32 vm_generation(struct virtio_device *vdev) |
235 | { |
236 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
237 | |
238 | if (vm_dev->version == 1) |
239 | return 0; |
240 | else |
241 | return readl(addr: vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); |
242 | } |
243 | |
244 | static u8 vm_get_status(struct virtio_device *vdev) |
245 | { |
246 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
247 | |
248 | return readl(addr: vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff; |
249 | } |
250 | |
251 | static void vm_set_status(struct virtio_device *vdev, u8 status) |
252 | { |
253 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
254 | |
255 | /* We should never be setting status to 0. */ |
256 | BUG_ON(status == 0); |
257 | |
258 | /* |
259 | * Per memory-barriers.txt, wmb() is not needed to guarantee |
260 | * that the cache coherent memory writes have completed |
261 | * before writing to the MMIO region. |
262 | */ |
263 | writel(val: status, addr: vm_dev->base + VIRTIO_MMIO_STATUS); |
264 | } |
265 | |
266 | static void vm_reset(struct virtio_device *vdev) |
267 | { |
268 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
269 | |
270 | /* 0 status means a reset. */ |
271 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_STATUS); |
272 | } |
273 | |
274 | |
275 | |
276 | /* Transport interface */ |
277 | |
278 | /* the notify function used when creating a virt queue */ |
279 | static bool vm_notify(struct virtqueue *vq) |
280 | { |
281 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); |
282 | |
283 | /* We write the queue's selector into the notification register to |
284 | * signal the other end */ |
285 | writel(val: vq->index, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); |
286 | return true; |
287 | } |
288 | |
289 | static bool vm_notify_with_data(struct virtqueue *vq) |
290 | { |
291 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); |
292 | u32 data = vring_notification_data(vq: vq); |
293 | |
294 | writel(val: data, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); |
295 | |
296 | return true; |
297 | } |
298 | |
299 | /* Notify all virtqueues on an interrupt. */ |
300 | static irqreturn_t vm_interrupt(int irq, void *opaque) |
301 | { |
302 | struct virtio_mmio_device *vm_dev = opaque; |
303 | struct virtio_mmio_vq_info *info; |
304 | unsigned long status; |
305 | unsigned long flags; |
306 | irqreturn_t ret = IRQ_NONE; |
307 | |
308 | /* Read and acknowledge interrupts */ |
309 | status = readl(addr: vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS); |
310 | writel(val: status, addr: vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK); |
311 | |
312 | if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { |
313 | virtio_config_changed(dev: &vm_dev->vdev); |
314 | ret = IRQ_HANDLED; |
315 | } |
316 | |
317 | if (likely(status & VIRTIO_MMIO_INT_VRING)) { |
318 | spin_lock_irqsave(&vm_dev->lock, flags); |
319 | list_for_each_entry(info, &vm_dev->virtqueues, node) |
320 | ret |= vring_interrupt(irq, vq: info->vq); |
321 | spin_unlock_irqrestore(lock: &vm_dev->lock, flags); |
322 | } |
323 | |
324 | return ret; |
325 | } |
326 | |
327 | |
328 | |
329 | static void vm_del_vq(struct virtqueue *vq) |
330 | { |
331 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); |
332 | struct virtio_mmio_vq_info *info = vq->priv; |
333 | unsigned long flags; |
334 | unsigned int index = vq->index; |
335 | |
336 | spin_lock_irqsave(&vm_dev->lock, flags); |
337 | list_del(entry: &info->node); |
338 | spin_unlock_irqrestore(lock: &vm_dev->lock, flags); |
339 | |
340 | /* Select and deactivate the queue */ |
341 | writel(val: index, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); |
342 | if (vm_dev->version == 1) { |
343 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); |
344 | } else { |
345 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_READY); |
346 | WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); |
347 | } |
348 | |
349 | vring_del_virtqueue(vq); |
350 | |
351 | kfree(objp: info); |
352 | } |
353 | |
354 | static void vm_del_vqs(struct virtio_device *vdev) |
355 | { |
356 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
357 | struct virtqueue *vq, *n; |
358 | |
359 | list_for_each_entry_safe(vq, n, &vdev->vqs, list) |
360 | vm_del_vq(vq); |
361 | |
362 | free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); |
363 | } |
364 | |
365 | static void vm_synchronize_cbs(struct virtio_device *vdev) |
366 | { |
367 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
368 | |
369 | synchronize_irq(irq: platform_get_irq(vm_dev->pdev, 0)); |
370 | } |
371 | |
372 | static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int index, |
373 | void (*callback)(struct virtqueue *vq), |
374 | const char *name, bool ctx) |
375 | { |
376 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
377 | bool (*notify)(struct virtqueue *vq); |
378 | struct virtio_mmio_vq_info *info; |
379 | struct virtqueue *vq; |
380 | unsigned long flags; |
381 | unsigned int num; |
382 | int err; |
383 | |
384 | if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA)) |
385 | notify = vm_notify_with_data; |
386 | else |
387 | notify = vm_notify; |
388 | |
389 | if (!name) |
390 | return NULL; |
391 | |
392 | /* Select the queue we're interested in */ |
393 | writel(val: index, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); |
394 | |
395 | /* Queue shouldn't already be set up. */ |
396 | if (readl(addr: vm_dev->base + (vm_dev->version == 1 ? |
397 | VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) { |
398 | err = -ENOENT; |
399 | goto error_available; |
400 | } |
401 | |
402 | /* Allocate and fill out our active queue description */ |
403 | info = kmalloc(size: sizeof(*info), GFP_KERNEL); |
404 | if (!info) { |
405 | err = -ENOMEM; |
406 | goto error_kmalloc; |
407 | } |
408 | |
409 | num = readl(addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX); |
410 | if (num == 0) { |
411 | err = -ENOENT; |
412 | goto error_new_virtqueue; |
413 | } |
414 | |
415 | /* Create the vring */ |
416 | vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, |
417 | weak_barriers: true, may_reduce_num: true, ctx, notify, callback, name); |
418 | if (!vq) { |
419 | err = -ENOMEM; |
420 | goto error_new_virtqueue; |
421 | } |
422 | |
423 | vq->num_max = num; |
424 | |
425 | /* Activate the queue */ |
426 | writel(val: virtqueue_get_vring_size(vq), addr: vm_dev->base + VIRTIO_MMIO_QUEUE_NUM); |
427 | if (vm_dev->version == 1) { |
428 | u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT; |
429 | |
430 | /* |
431 | * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something |
432 | * that doesn't fit in 32bit, fail the setup rather than |
433 | * pretending to be successful. |
434 | */ |
435 | if (q_pfn >> 32) { |
436 | dev_err(&vdev->dev, |
437 | "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n" , |
438 | 0x1ULL << (32 + PAGE_SHIFT - 30)); |
439 | err = -E2BIG; |
440 | goto error_bad_pfn; |
441 | } |
442 | |
443 | writel(PAGE_SIZE, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN); |
444 | writel(val: q_pfn, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); |
445 | } else { |
446 | u64 addr; |
447 | |
448 | addr = virtqueue_get_desc_addr(vq); |
449 | writel(val: (u32)addr, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW); |
450 | writel(val: (u32)(addr >> 32), |
451 | addr: vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH); |
452 | |
453 | addr = virtqueue_get_avail_addr(vq); |
454 | writel(val: (u32)addr, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW); |
455 | writel(val: (u32)(addr >> 32), |
456 | addr: vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH); |
457 | |
458 | addr = virtqueue_get_used_addr(vq); |
459 | writel(val: (u32)addr, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW); |
460 | writel(val: (u32)(addr >> 32), |
461 | addr: vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH); |
462 | |
463 | writel(val: 1, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_READY); |
464 | } |
465 | |
466 | vq->priv = info; |
467 | info->vq = vq; |
468 | |
469 | spin_lock_irqsave(&vm_dev->lock, flags); |
470 | list_add(new: &info->node, head: &vm_dev->virtqueues); |
471 | spin_unlock_irqrestore(lock: &vm_dev->lock, flags); |
472 | |
473 | return vq; |
474 | |
475 | error_bad_pfn: |
476 | vring_del_virtqueue(vq); |
477 | error_new_virtqueue: |
478 | if (vm_dev->version == 1) { |
479 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); |
480 | } else { |
481 | writel(val: 0, addr: vm_dev->base + VIRTIO_MMIO_QUEUE_READY); |
482 | WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY)); |
483 | } |
484 | kfree(objp: info); |
485 | error_kmalloc: |
486 | error_available: |
487 | return ERR_PTR(error: err); |
488 | } |
489 | |
490 | static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs, |
491 | struct virtqueue *vqs[], |
492 | vq_callback_t *callbacks[], |
493 | const char * const names[], |
494 | const bool *ctx, |
495 | struct irq_affinity *desc) |
496 | { |
497 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
498 | int irq = platform_get_irq(vm_dev->pdev, 0); |
499 | int i, err, queue_idx = 0; |
500 | |
501 | if (irq < 0) |
502 | return irq; |
503 | |
504 | err = request_irq(irq, handler: vm_interrupt, IRQF_SHARED, |
505 | name: dev_name(dev: &vdev->dev), dev: vm_dev); |
506 | if (err) |
507 | return err; |
508 | |
509 | if (of_property_read_bool(np: vm_dev->pdev->dev.of_node, propname: "wakeup-source" )) |
510 | enable_irq_wake(irq); |
511 | |
512 | for (i = 0; i < nvqs; ++i) { |
513 | if (!names[i]) { |
514 | vqs[i] = NULL; |
515 | continue; |
516 | } |
517 | |
518 | vqs[i] = vm_setup_vq(vdev, index: queue_idx++, callback: callbacks[i], name: names[i], |
519 | ctx: ctx ? ctx[i] : false); |
520 | if (IS_ERR(ptr: vqs[i])) { |
521 | vm_del_vqs(vdev); |
522 | return PTR_ERR(ptr: vqs[i]); |
523 | } |
524 | } |
525 | |
526 | return 0; |
527 | } |
528 | |
529 | static const char *vm_bus_name(struct virtio_device *vdev) |
530 | { |
531 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
532 | |
533 | return vm_dev->pdev->name; |
534 | } |
535 | |
536 | static bool vm_get_shm_region(struct virtio_device *vdev, |
537 | struct virtio_shm_region *region, u8 id) |
538 | { |
539 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
540 | u64 len, addr; |
541 | |
542 | /* Select the region we're interested in */ |
543 | writel(val: id, addr: vm_dev->base + VIRTIO_MMIO_SHM_SEL); |
544 | |
545 | /* Read the region size */ |
546 | len = (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); |
547 | len |= (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; |
548 | |
549 | region->len = len; |
550 | |
551 | /* Check if region length is -1. If that's the case, the shared memory |
552 | * region does not exist and there is no need to proceed further. |
553 | */ |
554 | if (len == ~(u64)0) |
555 | return false; |
556 | |
557 | /* Read the region base address */ |
558 | addr = (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); |
559 | addr |= (u64) readl(addr: vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; |
560 | |
561 | region->addr = addr; |
562 | |
563 | return true; |
564 | } |
565 | |
566 | static const struct virtio_config_ops virtio_mmio_config_ops = { |
567 | .get = vm_get, |
568 | .set = vm_set, |
569 | .generation = vm_generation, |
570 | .get_status = vm_get_status, |
571 | .set_status = vm_set_status, |
572 | .reset = vm_reset, |
573 | .find_vqs = vm_find_vqs, |
574 | .del_vqs = vm_del_vqs, |
575 | .get_features = vm_get_features, |
576 | .finalize_features = vm_finalize_features, |
577 | .bus_name = vm_bus_name, |
578 | .get_shm_region = vm_get_shm_region, |
579 | .synchronize_cbs = vm_synchronize_cbs, |
580 | }; |
581 | |
582 | #ifdef CONFIG_PM_SLEEP |
583 | static int virtio_mmio_freeze(struct device *dev) |
584 | { |
585 | struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); |
586 | |
587 | return virtio_device_freeze(dev: &vm_dev->vdev); |
588 | } |
589 | |
590 | static int virtio_mmio_restore(struct device *dev) |
591 | { |
592 | struct virtio_mmio_device *vm_dev = dev_get_drvdata(dev); |
593 | |
594 | if (vm_dev->version == 1) |
595 | writel(PAGE_SIZE, addr: vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); |
596 | |
597 | return virtio_device_restore(dev: &vm_dev->vdev); |
598 | } |
599 | |
600 | static const struct dev_pm_ops virtio_mmio_pm_ops = { |
601 | SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore) |
602 | }; |
603 | #endif |
604 | |
605 | static void virtio_mmio_release_dev(struct device *_d) |
606 | { |
607 | struct virtio_device *vdev = |
608 | container_of(_d, struct virtio_device, dev); |
609 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
610 | |
611 | kfree(objp: vm_dev); |
612 | } |
613 | |
614 | /* Platform device */ |
615 | |
616 | static int virtio_mmio_probe(struct platform_device *pdev) |
617 | { |
618 | struct virtio_mmio_device *vm_dev; |
619 | unsigned long magic; |
620 | int rc; |
621 | |
622 | vm_dev = kzalloc(size: sizeof(*vm_dev), GFP_KERNEL); |
623 | if (!vm_dev) |
624 | return -ENOMEM; |
625 | |
626 | vm_dev->vdev.dev.parent = &pdev->dev; |
627 | vm_dev->vdev.dev.release = virtio_mmio_release_dev; |
628 | vm_dev->vdev.config = &virtio_mmio_config_ops; |
629 | vm_dev->pdev = pdev; |
630 | INIT_LIST_HEAD(list: &vm_dev->virtqueues); |
631 | spin_lock_init(&vm_dev->lock); |
632 | |
633 | vm_dev->base = devm_platform_ioremap_resource(pdev, index: 0); |
634 | if (IS_ERR(ptr: vm_dev->base)) { |
635 | rc = PTR_ERR(ptr: vm_dev->base); |
636 | goto free_vm_dev; |
637 | } |
638 | |
639 | /* Check magic value */ |
640 | magic = readl(addr: vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); |
641 | if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { |
642 | dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n" , magic); |
643 | rc = -ENODEV; |
644 | goto free_vm_dev; |
645 | } |
646 | |
647 | /* Check device version */ |
648 | vm_dev->version = readl(addr: vm_dev->base + VIRTIO_MMIO_VERSION); |
649 | if (vm_dev->version < 1 || vm_dev->version > 2) { |
650 | dev_err(&pdev->dev, "Version %ld not supported!\n" , |
651 | vm_dev->version); |
652 | rc = -ENXIO; |
653 | goto free_vm_dev; |
654 | } |
655 | |
656 | vm_dev->vdev.id.device = readl(addr: vm_dev->base + VIRTIO_MMIO_DEVICE_ID); |
657 | if (vm_dev->vdev.id.device == 0) { |
658 | /* |
659 | * virtio-mmio device with an ID 0 is a (dummy) placeholder |
660 | * with no function. End probing now with no error reported. |
661 | */ |
662 | rc = -ENODEV; |
663 | goto free_vm_dev; |
664 | } |
665 | vm_dev->vdev.id.vendor = readl(addr: vm_dev->base + VIRTIO_MMIO_VENDOR_ID); |
666 | |
667 | if (vm_dev->version == 1) { |
668 | writel(PAGE_SIZE, addr: vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE); |
669 | |
670 | rc = dma_set_mask(dev: &pdev->dev, DMA_BIT_MASK(64)); |
671 | /* |
672 | * In the legacy case, ensure our coherently-allocated virtio |
673 | * ring will be at an address expressable as a 32-bit PFN. |
674 | */ |
675 | if (!rc) |
676 | dma_set_coherent_mask(dev: &pdev->dev, |
677 | DMA_BIT_MASK(32 + PAGE_SHIFT)); |
678 | } else { |
679 | rc = dma_set_mask_and_coherent(dev: &pdev->dev, DMA_BIT_MASK(64)); |
680 | } |
681 | if (rc) |
682 | rc = dma_set_mask_and_coherent(dev: &pdev->dev, DMA_BIT_MASK(32)); |
683 | if (rc) |
684 | dev_warn(&pdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n" ); |
685 | |
686 | platform_set_drvdata(pdev, data: vm_dev); |
687 | |
688 | rc = register_virtio_device(dev: &vm_dev->vdev); |
689 | if (rc) |
690 | put_device(dev: &vm_dev->vdev.dev); |
691 | |
692 | return rc; |
693 | |
694 | free_vm_dev: |
695 | kfree(objp: vm_dev); |
696 | return rc; |
697 | } |
698 | |
699 | static int virtio_mmio_remove(struct platform_device *pdev) |
700 | { |
701 | struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); |
702 | unregister_virtio_device(dev: &vm_dev->vdev); |
703 | |
704 | return 0; |
705 | } |
706 | |
707 | |
708 | |
709 | /* Devices list parameter */ |
710 | |
711 | #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) |
712 | |
713 | static struct device vm_cmdline_parent = { |
714 | .init_name = "virtio-mmio-cmdline" , |
715 | }; |
716 | |
717 | static int vm_cmdline_parent_registered; |
718 | static int vm_cmdline_id; |
719 | |
720 | static int vm_cmdline_set(const char *device, |
721 | const struct kernel_param *kp) |
722 | { |
723 | int err; |
724 | struct resource resources[2] = {}; |
725 | char *str; |
726 | long long base, size; |
727 | unsigned int irq; |
728 | int processed, consumed = 0; |
729 | struct platform_device *pdev; |
730 | |
731 | /* Consume "size" part of the command line parameter */ |
732 | size = memparse(ptr: device, retptr: &str); |
733 | |
734 | /* Get "@<base>:<irq>[:<id>]" chunks */ |
735 | processed = sscanf(str, "@%lli:%u%n:%d%n" , |
736 | &base, &irq, &consumed, |
737 | &vm_cmdline_id, &consumed); |
738 | |
739 | /* |
740 | * sscanf() must process at least 2 chunks; also there |
741 | * must be no extra characters after the last chunk, so |
742 | * str[consumed] must be '\0' |
743 | */ |
744 | if (processed < 2 || str[consumed] || irq == 0) |
745 | return -EINVAL; |
746 | |
747 | resources[0].flags = IORESOURCE_MEM; |
748 | resources[0].start = base; |
749 | resources[0].end = base + size - 1; |
750 | |
751 | resources[1].flags = IORESOURCE_IRQ; |
752 | resources[1].start = resources[1].end = irq; |
753 | |
754 | if (!vm_cmdline_parent_registered) { |
755 | err = device_register(dev: &vm_cmdline_parent); |
756 | if (err) { |
757 | put_device(dev: &vm_cmdline_parent); |
758 | pr_err("Failed to register parent device!\n" ); |
759 | return err; |
760 | } |
761 | vm_cmdline_parent_registered = 1; |
762 | } |
763 | |
764 | pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n" , |
765 | vm_cmdline_id, |
766 | (unsigned long long)resources[0].start, |
767 | (unsigned long long)resources[0].end, |
768 | (int)resources[1].start); |
769 | |
770 | pdev = platform_device_register_resndata(parent: &vm_cmdline_parent, |
771 | name: "virtio-mmio" , id: vm_cmdline_id++, |
772 | res: resources, ARRAY_SIZE(resources), NULL, size: 0); |
773 | |
774 | return PTR_ERR_OR_ZERO(ptr: pdev); |
775 | } |
776 | |
777 | static int vm_cmdline_get_device(struct device *dev, void *data) |
778 | { |
779 | char *buffer = data; |
780 | unsigned int len = strlen(buffer); |
781 | struct platform_device *pdev = to_platform_device(dev); |
782 | |
783 | snprintf(buf: buffer + len, PAGE_SIZE - len, fmt: "0x%llx@0x%llx:%llu:%d\n" , |
784 | pdev->resource[0].end - pdev->resource[0].start + 1ULL, |
785 | (unsigned long long)pdev->resource[0].start, |
786 | (unsigned long long)pdev->resource[1].start, |
787 | pdev->id); |
788 | return 0; |
789 | } |
790 | |
791 | static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) |
792 | { |
793 | buffer[0] = '\0'; |
794 | device_for_each_child(dev: &vm_cmdline_parent, data: buffer, |
795 | fn: vm_cmdline_get_device); |
796 | return strlen(buffer) + 1; |
797 | } |
798 | |
799 | static const struct kernel_param_ops vm_cmdline_param_ops = { |
800 | .set = vm_cmdline_set, |
801 | .get = vm_cmdline_get, |
802 | }; |
803 | |
804 | device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); |
805 | |
806 | static int vm_unregister_cmdline_device(struct device *dev, |
807 | void *data) |
808 | { |
809 | platform_device_unregister(to_platform_device(dev)); |
810 | |
811 | return 0; |
812 | } |
813 | |
814 | static void vm_unregister_cmdline_devices(void) |
815 | { |
816 | if (vm_cmdline_parent_registered) { |
817 | device_for_each_child(dev: &vm_cmdline_parent, NULL, |
818 | fn: vm_unregister_cmdline_device); |
819 | device_unregister(dev: &vm_cmdline_parent); |
820 | vm_cmdline_parent_registered = 0; |
821 | } |
822 | } |
823 | |
824 | #else |
825 | |
826 | static void vm_unregister_cmdline_devices(void) |
827 | { |
828 | } |
829 | |
830 | #endif |
831 | |
832 | /* Platform driver */ |
833 | |
834 | static const struct of_device_id virtio_mmio_match[] = { |
835 | { .compatible = "virtio,mmio" , }, |
836 | {}, |
837 | }; |
838 | MODULE_DEVICE_TABLE(of, virtio_mmio_match); |
839 | |
840 | #ifdef CONFIG_ACPI |
841 | static const struct acpi_device_id virtio_mmio_acpi_match[] = { |
842 | { "LNRO0005" , }, |
843 | { } |
844 | }; |
845 | MODULE_DEVICE_TABLE(acpi, virtio_mmio_acpi_match); |
846 | #endif |
847 | |
848 | static struct platform_driver virtio_mmio_driver = { |
849 | .probe = virtio_mmio_probe, |
850 | .remove = virtio_mmio_remove, |
851 | .driver = { |
852 | .name = "virtio-mmio" , |
853 | .of_match_table = virtio_mmio_match, |
854 | .acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match), |
855 | #ifdef CONFIG_PM_SLEEP |
856 | .pm = &virtio_mmio_pm_ops, |
857 | #endif |
858 | }, |
859 | }; |
860 | |
861 | static int __init virtio_mmio_init(void) |
862 | { |
863 | return platform_driver_register(&virtio_mmio_driver); |
864 | } |
865 | |
866 | static void __exit virtio_mmio_exit(void) |
867 | { |
868 | platform_driver_unregister(&virtio_mmio_driver); |
869 | vm_unregister_cmdline_devices(); |
870 | } |
871 | |
872 | module_init(virtio_mmio_init); |
873 | module_exit(virtio_mmio_exit); |
874 | |
875 | MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>" ); |
876 | MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices" ); |
877 | MODULE_LICENSE("GPL" ); |
878 | |