remove ioremap_nocache and devm_ioremap_nocache
[sfrench/cifs-2.6.git] / drivers / vfio / platform / vfio_platform_common.c
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
28 static LIST_HEAD(reset_list);
29 static DEFINE_MUTEX(driver_lock);
30
31 static 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(iter->owner)) {
41                         *module = iter->owner;
42                         reset_fn = iter->of_reset;
43                         break;
44                 }
45         }
46         mutex_unlock(&driver_lock);
47         return reset_fn;
48 }
49
50 static 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(adev);
67 #endif
68         return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
69 }
70
71 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
72                                   const char **extra_dbg)
73 {
74 #ifdef CONFIG_ACPI
75         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
76         struct device *dev = vdev->device;
77         acpi_handle handle = ACPI_HANDLE(dev);
78         acpi_status acpi_ret;
79
80         acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
81         if (ACPI_FAILURE(acpi_ret)) {
82                 if (extra_dbg)
83                         *extra_dbg = acpi_format_exception(acpi_ret);
84                 return -EINVAL;
85         }
86
87         return 0;
88 #else
89         return -ENOENT;
90 #endif
91 }
92
93 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
94 {
95 #ifdef CONFIG_ACPI
96         struct device *dev = vdev->device;
97         acpi_handle handle = ACPI_HANDLE(dev);
98
99         return acpi_has_method(handle, "_RST");
100 #else
101         return false;
102 #endif
103 }
104
105 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
106 {
107         if (VFIO_PLATFORM_IS_ACPI(vdev))
108                 return vfio_platform_acpi_has_reset(vdev);
109
110         return vdev->of_reset ? true : false;
111 }
112
113 static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
114 {
115         if (VFIO_PLATFORM_IS_ACPI(vdev))
116                 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
117
118         vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
119                                                     &vdev->reset_module);
120         if (!vdev->of_reset) {
121                 request_module("vfio-reset:%s", vdev->compat);
122                 vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
123                                                         &vdev->reset_module);
124         }
125
126         return vdev->of_reset ? 0 : -ENOENT;
127 }
128
129 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
130 {
131         if (VFIO_PLATFORM_IS_ACPI(vdev))
132                 return;
133
134         if (vdev->of_reset)
135                 module_put(vdev->reset_module);
136 }
137
138 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
139 {
140         int cnt = 0, i;
141
142         while (vdev->get_resource(vdev, cnt))
143                 cnt++;
144
145         vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
146                                 GFP_KERNEL);
147         if (!vdev->regions)
148                 return -ENOMEM;
149
150         for (i = 0; i < cnt;  i++) {
151                 struct resource *res =
152                         vdev->get_resource(vdev, i);
153
154                 if (!res)
155                         goto err;
156
157                 vdev->regions[i].addr = res->start;
158                 vdev->regions[i].size = resource_size(res);
159                 vdev->regions[i].flags = 0;
160
161                 switch (resource_type(res)) {
162                 case IORESOURCE_MEM:
163                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
164                         vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
165                         if (!(res->flags & IORESOURCE_READONLY))
166                                 vdev->regions[i].flags |=
167                                         VFIO_REGION_INFO_FLAG_WRITE;
168
169                         /*
170                          * Only regions addressed with PAGE granularity may be
171                          * MMAPed securely.
172                          */
173                         if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
174                                         !(vdev->regions[i].size & ~PAGE_MASK))
175                                 vdev->regions[i].flags |=
176                                         VFIO_REGION_INFO_FLAG_MMAP;
177
178                         break;
179                 case IORESOURCE_IO:
180                         vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
181                         break;
182                 default:
183                         goto err;
184                 }
185         }
186
187         vdev->num_regions = cnt;
188
189         return 0;
190 err:
191         kfree(vdev->regions);
192         return -EINVAL;
193 }
194
195 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
196 {
197         int i;
198
199         for (i = 0; i < vdev->num_regions; i++)
200                 iounmap(vdev->regions[i].ioaddr);
201
202         vdev->num_regions = 0;
203         kfree(vdev->regions);
204 }
205
206 static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
207                                     const char **extra_dbg)
208 {
209         if (VFIO_PLATFORM_IS_ACPI(vdev)) {
210                 dev_info(vdev->device, "reset\n");
211                 return vfio_platform_acpi_call_reset(vdev, extra_dbg);
212         } else if (vdev->of_reset) {
213                 dev_info(vdev->device, "reset\n");
214                 return vdev->of_reset(vdev);
215         }
216
217         dev_warn(vdev->device, "no reset function found!\n");
218         return -EINVAL;
219 }
220
221 static void vfio_platform_release(void *device_data)
222 {
223         struct vfio_platform_device *vdev = device_data;
224
225         mutex_lock(&driver_lock);
226
227         if (!(--vdev->refcnt)) {
228                 const char *extra_dbg = NULL;
229                 int ret;
230
231                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
232                 if (ret && vdev->reset_required) {
233                         dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
234                                  ret, extra_dbg ? extra_dbg : "");
235                         WARN_ON(1);
236                 }
237                 pm_runtime_put(vdev->device);
238                 vfio_platform_regions_cleanup(vdev);
239                 vfio_platform_irq_cleanup(vdev);
240         }
241
242         mutex_unlock(&driver_lock);
243
244         module_put(vdev->parent_module);
245 }
246
247 static int vfio_platform_open(void *device_data)
248 {
249         struct vfio_platform_device *vdev = device_data;
250         int ret;
251
252         if (!try_module_get(vdev->parent_module))
253                 return -ENODEV;
254
255         mutex_lock(&driver_lock);
256
257         if (!vdev->refcnt) {
258                 const char *extra_dbg = NULL;
259
260                 ret = vfio_platform_regions_init(vdev);
261                 if (ret)
262                         goto err_reg;
263
264                 ret = vfio_platform_irq_init(vdev);
265                 if (ret)
266                         goto err_irq;
267
268                 ret = pm_runtime_get_sync(vdev->device);
269                 if (ret < 0)
270                         goto err_pm;
271
272                 ret = vfio_platform_call_reset(vdev, &extra_dbg);
273                 if (ret && vdev->reset_required) {
274                         dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
275                                  ret, extra_dbg ? extra_dbg : "");
276                         goto err_rst;
277                 }
278         }
279
280         vdev->refcnt++;
281
282         mutex_unlock(&driver_lock);
283         return 0;
284
285 err_rst:
286         pm_runtime_put(vdev->device);
287 err_pm:
288         vfio_platform_irq_cleanup(vdev);
289 err_irq:
290         vfio_platform_regions_cleanup(vdev);
291 err_reg:
292         mutex_unlock(&driver_lock);
293         module_put(THIS_MODULE);
294         return ret;
295 }
296
297 static long vfio_platform_ioctl(void *device_data,
298                                 unsigned int cmd, unsigned long arg)
299 {
300         struct vfio_platform_device *vdev = device_data;
301         unsigned long minsz;
302
303         if (cmd == VFIO_DEVICE_GET_INFO) {
304                 struct vfio_device_info info;
305
306                 minsz = offsetofend(struct vfio_device_info, num_irqs);
307
308                 if (copy_from_user(&info, (void __user *)arg, minsz))
309                         return -EFAULT;
310
311                 if (info.argsz < minsz)
312                         return -EINVAL;
313
314                 if (vfio_platform_has_reset(vdev))
315                         vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
316                 info.flags = vdev->flags;
317                 info.num_regions = vdev->num_regions;
318                 info.num_irqs = vdev->num_irqs;
319
320                 return copy_to_user((void __user *)arg, &info, minsz) ?
321                         -EFAULT : 0;
322
323         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
324                 struct vfio_region_info info;
325
326                 minsz = offsetofend(struct vfio_region_info, offset);
327
328                 if (copy_from_user(&info, (void __user *)arg, minsz))
329                         return -EFAULT;
330
331                 if (info.argsz < minsz)
332                         return -EINVAL;
333
334                 if (info.index >= vdev->num_regions)
335                         return -EINVAL;
336
337                 /* map offset to the physical address  */
338                 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
339                 info.size = vdev->regions[info.index].size;
340                 info.flags = vdev->regions[info.index].flags;
341
342                 return copy_to_user((void __user *)arg, &info, minsz) ?
343                         -EFAULT : 0;
344
345         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
346                 struct vfio_irq_info info;
347
348                 minsz = offsetofend(struct vfio_irq_info, count);
349
350                 if (copy_from_user(&info, (void __user *)arg, minsz))
351                         return -EFAULT;
352
353                 if (info.argsz < minsz)
354                         return -EINVAL;
355
356                 if (info.index >= vdev->num_irqs)
357                         return -EINVAL;
358
359                 info.flags = vdev->irqs[info.index].flags;
360                 info.count = vdev->irqs[info.index].count;
361
362                 return copy_to_user((void __user *)arg, &info, minsz) ?
363                         -EFAULT : 0;
364
365         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
366                 struct vfio_irq_set hdr;
367                 u8 *data = NULL;
368                 int ret = 0;
369                 size_t data_size = 0;
370
371                 minsz = offsetofend(struct vfio_irq_set, count);
372
373                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
374                         return -EFAULT;
375
376                 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
377                                                  vdev->num_irqs, &data_size);
378                 if (ret)
379                         return ret;
380
381                 if (data_size) {
382                         data = memdup_user((void __user *)(arg + minsz),
383                                             data_size);
384                         if (IS_ERR(data))
385                                 return PTR_ERR(data);
386                 }
387
388                 mutex_lock(&vdev->igate);
389
390                 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
391                                                    hdr.start, hdr.count, data);
392                 mutex_unlock(&vdev->igate);
393                 kfree(data);
394
395                 return ret;
396
397         } else if (cmd == VFIO_DEVICE_RESET) {
398                 return vfio_platform_call_reset(vdev, NULL);
399         }
400
401         return -ENOTTY;
402 }
403
404 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
405                                        char __user *buf, size_t count,
406                                        loff_t off)
407 {
408         unsigned int done = 0;
409
410         if (!reg->ioaddr) {
411                 reg->ioaddr =
412                         ioremap(reg->addr, reg->size);
413
414                 if (!reg->ioaddr)
415                         return -ENOMEM;
416         }
417
418         while (count) {
419                 size_t filled;
420
421                 if (count >= 4 && !(off % 4)) {
422                         u32 val;
423
424                         val = ioread32(reg->ioaddr + off);
425                         if (copy_to_user(buf, &val, 4))
426                                 goto err;
427
428                         filled = 4;
429                 } else if (count >= 2 && !(off % 2)) {
430                         u16 val;
431
432                         val = ioread16(reg->ioaddr + off);
433                         if (copy_to_user(buf, &val, 2))
434                                 goto err;
435
436                         filled = 2;
437                 } else {
438                         u8 val;
439
440                         val = ioread8(reg->ioaddr + off);
441                         if (copy_to_user(buf, &val, 1))
442                                 goto err;
443
444                         filled = 1;
445                 }
446
447
448                 count -= filled;
449                 done += filled;
450                 off += filled;
451                 buf += filled;
452         }
453
454         return done;
455 err:
456         return -EFAULT;
457 }
458
459 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
460                                   size_t count, loff_t *ppos)
461 {
462         struct vfio_platform_device *vdev = device_data;
463         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
464         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
465
466         if (index >= vdev->num_regions)
467                 return -EINVAL;
468
469         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
470                 return -EINVAL;
471
472         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
473                 return vfio_platform_read_mmio(&vdev->regions[index],
474                                                         buf, count, off);
475         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
476                 return -EINVAL; /* not implemented */
477
478         return -EINVAL;
479 }
480
481 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
482                                         const char __user *buf, size_t count,
483                                         loff_t off)
484 {
485         unsigned int done = 0;
486
487         if (!reg->ioaddr) {
488                 reg->ioaddr =
489                         ioremap(reg->addr, reg->size);
490
491                 if (!reg->ioaddr)
492                         return -ENOMEM;
493         }
494
495         while (count) {
496                 size_t filled;
497
498                 if (count >= 4 && !(off % 4)) {
499                         u32 val;
500
501                         if (copy_from_user(&val, buf, 4))
502                                 goto err;
503                         iowrite32(val, reg->ioaddr + off);
504
505                         filled = 4;
506                 } else if (count >= 2 && !(off % 2)) {
507                         u16 val;
508
509                         if (copy_from_user(&val, buf, 2))
510                                 goto err;
511                         iowrite16(val, reg->ioaddr + off);
512
513                         filled = 2;
514                 } else {
515                         u8 val;
516
517                         if (copy_from_user(&val, buf, 1))
518                                 goto err;
519                         iowrite8(val, reg->ioaddr + off);
520
521                         filled = 1;
522                 }
523
524                 count -= filled;
525                 done += filled;
526                 off += filled;
527                 buf += filled;
528         }
529
530         return done;
531 err:
532         return -EFAULT;
533 }
534
535 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
536                                    size_t count, loff_t *ppos)
537 {
538         struct vfio_platform_device *vdev = device_data;
539         unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
540         loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
541
542         if (index >= vdev->num_regions)
543                 return -EINVAL;
544
545         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
546                 return -EINVAL;
547
548         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
549                 return vfio_platform_write_mmio(&vdev->regions[index],
550                                                         buf, count, off);
551         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
552                 return -EINVAL; /* not implemented */
553
554         return -EINVAL;
555 }
556
557 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
558                                    struct vm_area_struct *vma)
559 {
560         u64 req_len, pgoff, req_start;
561
562         req_len = vma->vm_end - vma->vm_start;
563         pgoff = vma->vm_pgoff &
564                 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
565         req_start = pgoff << PAGE_SHIFT;
566
567         if (region.size < PAGE_SIZE || req_start + req_len > region.size)
568                 return -EINVAL;
569
570         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
571         vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
572
573         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
574                                req_len, vma->vm_page_prot);
575 }
576
577 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
578 {
579         struct vfio_platform_device *vdev = device_data;
580         unsigned int index;
581
582         index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
583
584         if (vma->vm_end < vma->vm_start)
585                 return -EINVAL;
586         if (!(vma->vm_flags & VM_SHARED))
587                 return -EINVAL;
588         if (index >= vdev->num_regions)
589                 return -EINVAL;
590         if (vma->vm_start & ~PAGE_MASK)
591                 return -EINVAL;
592         if (vma->vm_end & ~PAGE_MASK)
593                 return -EINVAL;
594
595         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
596                 return -EINVAL;
597
598         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
599                         && (vma->vm_flags & VM_READ))
600                 return -EINVAL;
601
602         if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
603                         && (vma->vm_flags & VM_WRITE))
604                 return -EINVAL;
605
606         vma->vm_private_data = vdev;
607
608         if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
609                 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
610
611         else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
612                 return -EINVAL; /* not implemented */
613
614         return -EINVAL;
615 }
616
617 static const struct vfio_device_ops vfio_platform_ops = {
618         .name           = "vfio-platform",
619         .open           = vfio_platform_open,
620         .release        = vfio_platform_release,
621         .ioctl          = vfio_platform_ioctl,
622         .read           = vfio_platform_read,
623         .write          = vfio_platform_write,
624         .mmap           = vfio_platform_mmap,
625 };
626
627 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
628                            struct device *dev)
629 {
630         int ret;
631
632         ret = device_property_read_string(dev, "compatible",
633                                           &vdev->compat);
634         if (ret)
635                 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name);
636
637         return ret;
638 }
639
640 /*
641  * There can be two kernel build combinations. One build where
642  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
643  *
644  * In the first case, vfio_platform_acpi_probe will return since
645  * acpi_disabled is 1. DT user will not see any kind of messages from
646  * ACPI.
647  *
648  * In the second case, both DT and ACPI is compiled in but the system is
649  * booting with any of these combinations.
650  *
651  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
652  * terminates immediately without any messages.
653  *
654  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
655  * valid checks. We cannot claim that this system is DT.
656  */
657 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
658                                struct device *dev)
659 {
660         struct iommu_group *group;
661         int ret;
662
663         if (!vdev)
664                 return -EINVAL;
665
666         ret = vfio_platform_acpi_probe(vdev, dev);
667         if (ret)
668                 ret = vfio_platform_of_probe(vdev, dev);
669
670         if (ret)
671                 return ret;
672
673         vdev->device = dev;
674
675         ret = vfio_platform_get_reset(vdev);
676         if (ret && vdev->reset_required) {
677                 dev_err(dev, "No reset function found for device %s\n",
678                         vdev->name);
679                 return ret;
680         }
681
682         group = vfio_iommu_group_get(dev);
683         if (!group) {
684                 dev_err(dev, "No IOMMU group for device %s\n", vdev->name);
685                 ret = -EINVAL;
686                 goto put_reset;
687         }
688
689         ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
690         if (ret)
691                 goto put_iommu;
692
693         mutex_init(&vdev->igate);
694
695         pm_runtime_enable(vdev->device);
696         return 0;
697
698 put_iommu:
699         vfio_iommu_group_put(group, dev);
700 put_reset:
701         vfio_platform_put_reset(vdev);
702         return ret;
703 }
704 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
705
706 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
707 {
708         struct vfio_platform_device *vdev;
709
710         vdev = vfio_del_group_dev(dev);
711
712         if (vdev) {
713                 pm_runtime_disable(vdev->device);
714                 vfio_platform_put_reset(vdev);
715                 vfio_iommu_group_put(dev->iommu_group, dev);
716         }
717
718         return vdev;
719 }
720 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
721
722 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
723 {
724         mutex_lock(&driver_lock);
725         list_add(&node->link, &reset_list);
726         mutex_unlock(&driver_lock);
727 }
728 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
729
730 void vfio_platform_unregister_reset(const char *compat,
731                                     vfio_platform_reset_fn_t fn)
732 {
733         struct vfio_platform_reset_node *iter, *temp;
734
735         mutex_lock(&driver_lock);
736         list_for_each_entry_safe(iter, temp, &reset_list, link) {
737                 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
738                         list_del(&iter->link);
739                         break;
740                 }
741         }
742
743         mutex_unlock(&driver_lock);
744
745 }
746 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
747
748 MODULE_VERSION(DRIVER_VERSION);
749 MODULE_LICENSE("GPL v2");
750 MODULE_AUTHOR(DRIVER_AUTHOR);
751 MODULE_DESCRIPTION(DRIVER_DESC);