1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 - Virtual Open Systems
4 * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
5 */
6
7#define dev_fmt(fmt) "VFIO: " fmt
8
9#include <linux/device.h>
10#include <linux/acpi.h>
11#include <linux/iommu.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/pm_runtime.h>
15#include <linux/slab.h>
16#include <linux/types.h>
17#include <linux/uaccess.h>
18#include <linux/vfio.h>
19
20#include "vfio_platform_private.h"
21
22#define DRIVER_VERSION "0.10"
23#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>"
24#define DRIVER_DESC "VFIO platform base module"
25
26#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
27
28static LIST_HEAD(reset_list);
29static DEFINE_MUTEX(driver_lock);
30
31static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
32 struct module **module)
33{
34 struct vfio_platform_reset_node *iter;
35 vfio_platform_reset_fn_t reset_fn = NULL;
36
37 mutex_lock(&driver_lock);
38 list_for_each_entry(iter, &reset_list, link) {
39 if (!strcmp(iter->compat, compat) &&
40 try_module_get(module: iter->owner)) {
41 *module = iter->owner;
42 reset_fn = iter->of_reset;
43 break;
44 }
45 }
46 mutex_unlock(lock: &driver_lock);
47 return reset_fn;
48}
49
50static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
51 struct device *dev)
52{
53 struct acpi_device *adev;
54
55 if (acpi_disabled)
56 return -ENOENT;
57
58 adev = ACPI_COMPANION(dev);
59 if (!adev) {
60 dev_err(dev, "ACPI companion device not found for %s\n",
61 vdev->name);
62 return -ENODEV;
63 }
64
65#ifdef CONFIG_ACPI
66 vdev->acpihid = acpi_device_hid(device: adev);
67#endif
68 return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
69}
70
71static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
72 const char **extra_dbg)
73{
74#ifdef CONFIG_ACPI
75 struct device *dev = vdev->device;
76 acpi_handle handle = ACPI_HANDLE(dev);
77 acpi_status acpi_ret;
78
79 acpi_ret = acpi_evaluate_object(object: handle, pathname: "_RST", NULL, NULL);
80 if (ACPI_FAILURE(acpi_ret)) {
81 if (extra_dbg)
82 *extra_dbg = acpi_format_exception(exception: acpi_ret);
83 return -EINVAL;
84 }
85
86 return 0;
87#else
88 return -ENOENT;
89#endif
90}
91
92static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
93{
94#ifdef CONFIG_ACPI
95 struct device *dev = vdev->device;
96 acpi_handle handle = ACPI_HANDLE(dev);
97
98 return acpi_has_method(handle, name: "_RST");
99#else
100 return false;
101#endif
102}
103
104static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
105{
106 if (VFIO_PLATFORM_IS_ACPI(vdev))
107 return vfio_platform_acpi_has_reset(vdev);
108
109 return vdev->of_reset ? true : false;
110}
111
112static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
113{
114 if (VFIO_PLATFORM_IS_ACPI(vdev))
115 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
116
117 vdev->of_reset = vfio_platform_lookup_reset(compat: vdev->compat,
118 module: &vdev->reset_module);
119 if (!vdev->of_reset) {
120 request_module("vfio-reset:%s", vdev->compat);
121 vdev->of_reset = vfio_platform_lookup_reset(compat: vdev->compat,
122 module: &vdev->reset_module);
123 }
124
125 return vdev->of_reset ? 0 : -ENOENT;
126}
127
128static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
129{
130 if (VFIO_PLATFORM_IS_ACPI(vdev))
131 return;
132
133 if (vdev->of_reset)
134 module_put(module: vdev->reset_module);
135}
136
137static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
138{
139 int cnt = 0, i;
140
141 while (vdev->get_resource(vdev, cnt))
142 cnt++;
143
144 vdev->regions = kcalloc(n: cnt, size: sizeof(struct vfio_platform_region),
145 GFP_KERNEL_ACCOUNT);
146 if (!vdev->regions)
147 return -ENOMEM;
148
149 for (i = 0; i < cnt; i++) {
150 struct resource *res =
151 vdev->get_resource(vdev, i);
152
153 vdev->regions[i].addr = res->start;
154 vdev->regions[i].size = resource_size(res);
155 vdev->regions[i].flags = 0;
156
157 switch (resource_type(res)) {
158 case IORESOURCE_MEM:
159 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
160 vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
161 if (!(res->flags & IORESOURCE_READONLY))
162 vdev->regions[i].flags |=
163 VFIO_REGION_INFO_FLAG_WRITE;
164
165 /*
166 * Only regions addressed with PAGE granularity may be
167 * MMAPed securely.
168 */
169 if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
170 !(vdev->regions[i].size & ~PAGE_MASK))
171 vdev->regions[i].flags |=
172 VFIO_REGION_INFO_FLAG_MMAP;
173
174 break;
175 case IORESOURCE_IO:
176 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
177 break;
178 default:
179 goto err;
180 }
181 }
182
183 vdev->num_regions = cnt;
184
185 return 0;
186err:
187 kfree(objp: vdev->regions);
188 return -EINVAL;
189}
190
191static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
192{
193 int i;
194
195 for (i = 0; i < vdev->num_regions; i++)
196 iounmap(addr: vdev->regions[i].ioaddr);
197
198 vdev->num_regions = 0;
199 kfree(objp: vdev->regions);
200}
201
202static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
203 const char **extra_dbg)
204{
205 if (VFIO_PLATFORM_IS_ACPI(vdev)) {
206 dev_info(vdev->device, "reset\n");
207 return vfio_platform_acpi_call_reset(vdev, extra_dbg);
208 } else if (vdev->of_reset) {
209 dev_info(vdev->device, "reset\n");
210 return vdev->of_reset(vdev);
211 }
212
213 dev_warn(vdev->device, "no reset function found!\n");
214 return -EINVAL;
215}
216
217void vfio_platform_close_device(struct vfio_device *core_vdev)
218{
219 struct vfio_platform_device *vdev =
220 container_of(core_vdev, struct vfio_platform_device, vdev);
221 const char *extra_dbg = NULL;
222 int ret;
223
224 ret = vfio_platform_call_reset(vdev, extra_dbg: &extra_dbg);
225 if (WARN_ON(ret && vdev->reset_required)) {
226 dev_warn(
227 vdev->device,
228 "reset driver is required and reset call failed in release (%d) %s\n",
229 ret, extra_dbg ? extra_dbg : "");
230 }
231 pm_runtime_put(dev: vdev->device);
232 vfio_platform_regions_cleanup(vdev);
233 vfio_platform_irq_cleanup(vdev);
234}
235EXPORT_SYMBOL_GPL(vfio_platform_close_device);
236
237int vfio_platform_open_device(struct vfio_device *core_vdev)
238{
239 struct vfio_platform_device *vdev =
240 container_of(core_vdev, struct vfio_platform_device, vdev);
241 const char *extra_dbg = NULL;
242 int ret;
243
244 ret = vfio_platform_regions_init(vdev);
245 if (ret)
246 return ret;
247
248 ret = vfio_platform_irq_init(vdev);
249 if (ret)
250 goto err_irq;
251
252 ret = pm_runtime_get_sync(dev: vdev->device);
253 if (ret < 0)
254 goto err_rst;
255
256 ret = vfio_platform_call_reset(vdev, extra_dbg: &extra_dbg);
257 if (ret && vdev->reset_required) {
258 dev_warn(
259 vdev->device,
260 "reset driver is required and reset call failed in open (%d) %s\n",
261 ret, extra_dbg ? extra_dbg : "");
262 goto err_rst;
263 }
264 return 0;
265
266err_rst:
267 pm_runtime_put(dev: vdev->device);
268 vfio_platform_irq_cleanup(vdev);
269err_irq:
270 vfio_platform_regions_cleanup(vdev);
271 return ret;
272}
273EXPORT_SYMBOL_GPL(vfio_platform_open_device);
274
275long vfio_platform_ioctl(struct vfio_device *core_vdev,
276 unsigned int cmd, unsigned long arg)
277{
278 struct vfio_platform_device *vdev =
279 container_of(core_vdev, struct vfio_platform_device, vdev);
280
281 unsigned long minsz;
282
283 if (cmd == VFIO_DEVICE_GET_INFO) {
284 struct vfio_device_info info;
285
286 minsz = offsetofend(struct vfio_device_info, num_irqs);
287
288 if (copy_from_user(to: &info, from: (void __user *)arg, n: minsz))
289 return -EFAULT;
290
291 if (info.argsz < minsz)
292 return -EINVAL;
293
294 if (vfio_platform_has_reset(vdev))
295 vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
296 info.flags = vdev->flags;
297 info.num_regions = vdev->num_regions;
298 info.num_irqs = vdev->num_irqs;
299
300 return copy_to_user(to: (void __user *)arg, from: &info, n: minsz) ?
301 -EFAULT : 0;
302
303 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
304 struct vfio_region_info info;
305
306 minsz = offsetofend(struct vfio_region_info, offset);
307
308 if (copy_from_user(to: &info, from: (void __user *)arg, n: minsz))
309 return -EFAULT;
310
311 if (info.argsz < minsz)
312 return -EINVAL;
313
314 if (info.index >= vdev->num_regions)
315 return -EINVAL;
316
317 /* map offset to the physical address */
318 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
319 info.size = vdev->regions[info.index].size;
320 info.flags = vdev->regions[info.index].flags;
321
322 return copy_to_user(to: (void __user *)arg, from: &info, n: minsz) ?
323 -EFAULT : 0;
324
325 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
326 struct vfio_irq_info info;
327
328 minsz = offsetofend(struct vfio_irq_info, count);
329
330 if (copy_from_user(to: &info, from: (void __user *)arg, n: minsz))
331 return -EFAULT;
332
333 if (info.argsz < minsz)
334 return -EINVAL;
335
336 if (info.index >= vdev->num_irqs)
337 return -EINVAL;
338
339 info.flags = vdev->irqs[info.index].flags;
340 info.count = vdev->irqs[info.index].count;
341
342 return copy_to_user(to: (void __user *)arg, from: &info, n: minsz) ?
343 -EFAULT : 0;
344
345 } else if (cmd == VFIO_DEVICE_SET_IRQS) {
346 struct vfio_irq_set hdr;
347 u8 *data = NULL;
348 int ret = 0;
349 size_t data_size = 0;
350
351 minsz = offsetofend(struct vfio_irq_set, count);
352
353 if (copy_from_user(to: &hdr, from: (void __user *)arg, n: minsz))
354 return -EFAULT;
355
356 ret = vfio_set_irqs_validate_and_prepare(hdr: &hdr, num_irqs: vdev->num_irqs,
357 max_irq_type: vdev->num_irqs, data_size: &data_size);
358 if (ret)
359 return ret;
360
361 if (data_size) {
362 data = memdup_user((void __user *)(arg + minsz),
363 data_size);
364 if (IS_ERR(ptr: data))
365 return PTR_ERR(ptr: data);
366 }
367
368 mutex_lock(&vdev->igate);
369
370 ret = vfio_platform_set_irqs_ioctl(vdev, flags: hdr.flags, index: hdr.index,
371 start: hdr.start, count: hdr.count, data);
372 mutex_unlock(lock: &vdev->igate);
373 kfree(objp: data);
374
375 return ret;
376
377 } else if (cmd == VFIO_DEVICE_RESET) {
378 return vfio_platform_call_reset(vdev, NULL);
379 }
380
381 return -ENOTTY;
382}
383EXPORT_SYMBOL_GPL(vfio_platform_ioctl);
384
385static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
386 char __user *buf, size_t count,
387 loff_t off)
388{
389 unsigned int done = 0;
390
391 if (!reg->ioaddr) {
392 reg->ioaddr =
393 ioremap(offset: reg->addr, size: reg->size);
394
395 if (!reg->ioaddr)
396 return -ENOMEM;
397 }
398
399 while (count) {
400 size_t filled;
401
402 if (count >= 4 && !(off % 4)) {
403 u32 val;
404
405 val = ioread32(reg->ioaddr + off);
406 if (copy_to_user(to: buf, from: &val, n: 4))
407 goto err;
408
409 filled = 4;
410 } else if (count >= 2 && !(off % 2)) {
411 u16 val;
412
413 val = ioread16(reg->ioaddr + off);
414 if (copy_to_user(to: buf, from: &val, n: 2))
415 goto err;
416
417 filled = 2;
418 } else {
419 u8 val;
420
421 val = ioread8(reg->ioaddr + off);
422 if (copy_to_user(to: buf, from: &val, n: 1))
423 goto err;
424
425 filled = 1;
426 }
427
428
429 count -= filled;
430 done += filled;
431 off += filled;
432 buf += filled;
433 }
434
435 return done;
436err:
437 return -EFAULT;
438}
439
440ssize_t vfio_platform_read(struct vfio_device *core_vdev,
441 char __user *buf, size_t count, loff_t *ppos)
442{
443 struct vfio_platform_device *vdev =
444 container_of(core_vdev, struct vfio_platform_device, vdev);
445 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
446 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
447
448 if (index >= vdev->num_regions)
449 return -EINVAL;
450
451 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
452 return -EINVAL;
453
454 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
455 return vfio_platform_read_mmio(reg: &vdev->regions[index],
456 buf, count, off);
457 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
458 return -EINVAL; /* not implemented */
459
460 return -EINVAL;
461}
462EXPORT_SYMBOL_GPL(vfio_platform_read);
463
464static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
465 const char __user *buf, size_t count,
466 loff_t off)
467{
468 unsigned int done = 0;
469
470 if (!reg->ioaddr) {
471 reg->ioaddr =
472 ioremap(offset: reg->addr, size: reg->size);
473
474 if (!reg->ioaddr)
475 return -ENOMEM;
476 }
477
478 while (count) {
479 size_t filled;
480
481 if (count >= 4 && !(off % 4)) {
482 u32 val;
483
484 if (copy_from_user(to: &val, from: buf, n: 4))
485 goto err;
486 iowrite32(val, reg->ioaddr + off);
487
488 filled = 4;
489 } else if (count >= 2 && !(off % 2)) {
490 u16 val;
491
492 if (copy_from_user(to: &val, from: buf, n: 2))
493 goto err;
494 iowrite16(val, reg->ioaddr + off);
495
496 filled = 2;
497 } else {
498 u8 val;
499
500 if (copy_from_user(to: &val, from: buf, n: 1))
501 goto err;
502 iowrite8(val, reg->ioaddr + off);
503
504 filled = 1;
505 }
506
507 count -= filled;
508 done += filled;
509 off += filled;
510 buf += filled;
511 }
512
513 return done;
514err:
515 return -EFAULT;
516}
517
518ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
519 size_t count, loff_t *ppos)
520{
521 struct vfio_platform_device *vdev =
522 container_of(core_vdev, struct vfio_platform_device, vdev);
523 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
524 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
525
526 if (index >= vdev->num_regions)
527 return -EINVAL;
528
529 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
530 return -EINVAL;
531
532 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
533 return vfio_platform_write_mmio(reg: &vdev->regions[index],
534 buf, count, off);
535 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
536 return -EINVAL; /* not implemented */
537
538 return -EINVAL;
539}
540EXPORT_SYMBOL_GPL(vfio_platform_write);
541
542static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
543 struct vm_area_struct *vma)
544{
545 u64 req_len, pgoff, req_start;
546
547 req_len = vma->vm_end - vma->vm_start;
548 pgoff = vma->vm_pgoff &
549 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
550 req_start = pgoff << PAGE_SHIFT;
551
552 if (region.size < PAGE_SIZE || req_start + req_len > region.size)
553 return -EINVAL;
554
555 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
556 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
557
558 return remap_pfn_range(vma, addr: vma->vm_start, pfn: vma->vm_pgoff,
559 size: req_len, vma->vm_page_prot);
560}
561
562int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
563{
564 struct vfio_platform_device *vdev =
565 container_of(core_vdev, struct vfio_platform_device, vdev);
566 unsigned int index;
567
568 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
569
570 if (vma->vm_end < vma->vm_start)
571 return -EINVAL;
572 if (!(vma->vm_flags & VM_SHARED))
573 return -EINVAL;
574 if (index >= vdev->num_regions)
575 return -EINVAL;
576 if (vma->vm_start & ~PAGE_MASK)
577 return -EINVAL;
578 if (vma->vm_end & ~PAGE_MASK)
579 return -EINVAL;
580
581 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
582 return -EINVAL;
583
584 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
585 && (vma->vm_flags & VM_READ))
586 return -EINVAL;
587
588 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
589 && (vma->vm_flags & VM_WRITE))
590 return -EINVAL;
591
592 vma->vm_private_data = vdev;
593
594 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
595 return vfio_platform_mmap_mmio(region: vdev->regions[index], vma);
596
597 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
598 return -EINVAL; /* not implemented */
599
600 return -EINVAL;
601}
602EXPORT_SYMBOL_GPL(vfio_platform_mmap);
603
604static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
605 struct device *dev)
606{
607 int ret;
608
609 ret = device_property_read_string(dev, propname: "compatible",
610 val: &vdev->compat);
611 if (ret)
612 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name);
613
614 return ret;
615}
616
617/*
618 * There can be two kernel build combinations. One build where
619 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
620 *
621 * In the first case, vfio_platform_acpi_probe will return since
622 * acpi_disabled is 1. DT user will not see any kind of messages from
623 * ACPI.
624 *
625 * In the second case, both DT and ACPI is compiled in but the system is
626 * booting with any of these combinations.
627 *
628 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
629 * terminates immediately without any messages.
630 *
631 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
632 * valid checks. We cannot claim that this system is DT.
633 */
634int vfio_platform_init_common(struct vfio_platform_device *vdev)
635{
636 int ret;
637 struct device *dev = vdev->vdev.dev;
638
639 ret = vfio_platform_acpi_probe(vdev, dev);
640 if (ret)
641 ret = vfio_platform_of_probe(vdev, dev);
642
643 if (ret)
644 return ret;
645
646 vdev->device = dev;
647 mutex_init(&vdev->igate);
648
649 ret = vfio_platform_get_reset(vdev);
650 if (ret && vdev->reset_required) {
651 dev_err(dev, "No reset function found for device %s\n",
652 vdev->name);
653 return ret;
654 }
655
656 return 0;
657}
658EXPORT_SYMBOL_GPL(vfio_platform_init_common);
659
660void vfio_platform_release_common(struct vfio_platform_device *vdev)
661{
662 vfio_platform_put_reset(vdev);
663}
664EXPORT_SYMBOL_GPL(vfio_platform_release_common);
665
666void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
667{
668 mutex_lock(&driver_lock);
669 list_add(new: &node->link, head: &reset_list);
670 mutex_unlock(lock: &driver_lock);
671}
672EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
673
674void vfio_platform_unregister_reset(const char *compat,
675 vfio_platform_reset_fn_t fn)
676{
677 struct vfio_platform_reset_node *iter, *temp;
678
679 mutex_lock(&driver_lock);
680 list_for_each_entry_safe(iter, temp, &reset_list, link) {
681 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
682 list_del(entry: &iter->link);
683 break;
684 }
685 }
686
687 mutex_unlock(lock: &driver_lock);
688
689}
690EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
691
692MODULE_VERSION(DRIVER_VERSION);
693MODULE_LICENSE("GPL v2");
694MODULE_AUTHOR(DRIVER_AUTHOR);
695MODULE_DESCRIPTION(DRIVER_DESC);
696

source code of linux/drivers/vfio/platform/vfio_platform_common.c