1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2013 - Virtual Open Systems
4 * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
7 #define dev_fmt(fmt) "VFIO: " fmt
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>
20 #include "vfio_platform_private.h"
22 #define DRIVER_VERSION "0.10"
23 #define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>"
24 #define DRIVER_DESC "VFIO platform base module"
26 #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
28 static LIST_HEAD(reset_list);
29 static DEFINE_MUTEX(driver_lock);
31 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
32 struct module **module)
34 struct vfio_platform_reset_node *iter;
35 vfio_platform_reset_fn_t reset_fn = NULL;
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;
46 mutex_unlock(&driver_lock);
50 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
53 struct acpi_device *adev;
58 adev = ACPI_COMPANION(dev);
60 dev_err(dev, "ACPI companion device not found for %s\n",
66 vdev->acpihid = acpi_device_hid(adev);
68 return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
71 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
72 const char **extra_dbg)
75 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
76 struct device *dev = vdev->device;
77 acpi_handle handle = ACPI_HANDLE(dev);
80 acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
81 if (ACPI_FAILURE(acpi_ret)) {
83 *extra_dbg = acpi_format_exception(acpi_ret);
93 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
96 struct device *dev = vdev->device;
97 acpi_handle handle = ACPI_HANDLE(dev);
99 return acpi_has_method(handle, "_RST");
105 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
107 if (VFIO_PLATFORM_IS_ACPI(vdev))
108 return vfio_platform_acpi_has_reset(vdev);
110 return vdev->of_reset ? true : false;
113 static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
115 if (VFIO_PLATFORM_IS_ACPI(vdev))
116 return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
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);
126 return vdev->of_reset ? 0 : -ENOENT;
129 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
131 if (VFIO_PLATFORM_IS_ACPI(vdev))
135 module_put(vdev->reset_module);
138 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
142 while (vdev->get_resource(vdev, cnt))
145 vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
150 for (i = 0; i < cnt; i++) {
151 struct resource *res =
152 vdev->get_resource(vdev, i);
157 vdev->regions[i].addr = res->start;
158 vdev->regions[i].size = resource_size(res);
159 vdev->regions[i].flags = 0;
161 switch (resource_type(res)) {
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;
170 * Only regions addressed with PAGE granularity may be
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;
180 vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
187 vdev->num_regions = cnt;
191 kfree(vdev->regions);
195 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
199 for (i = 0; i < vdev->num_regions; i++)
200 iounmap(vdev->regions[i].ioaddr);
202 vdev->num_regions = 0;
203 kfree(vdev->regions);
206 static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
207 const char **extra_dbg)
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);
217 dev_warn(vdev->device, "no reset function found!\n");
221 static void vfio_platform_release(struct vfio_device *core_vdev)
223 struct vfio_platform_device *vdev =
224 container_of(core_vdev, struct vfio_platform_device, vdev);
226 mutex_lock(&driver_lock);
228 if (!(--vdev->refcnt)) {
229 const char *extra_dbg = NULL;
232 ret = vfio_platform_call_reset(vdev, &extra_dbg);
233 if (ret && vdev->reset_required) {
234 dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
235 ret, extra_dbg ? extra_dbg : "");
238 pm_runtime_put(vdev->device);
239 vfio_platform_regions_cleanup(vdev);
240 vfio_platform_irq_cleanup(vdev);
243 mutex_unlock(&driver_lock);
245 module_put(vdev->parent_module);
248 static int vfio_platform_open(struct vfio_device *core_vdev)
250 struct vfio_platform_device *vdev =
251 container_of(core_vdev, struct vfio_platform_device, vdev);
254 if (!try_module_get(vdev->parent_module))
257 mutex_lock(&driver_lock);
260 const char *extra_dbg = NULL;
262 ret = vfio_platform_regions_init(vdev);
266 ret = vfio_platform_irq_init(vdev);
270 ret = pm_runtime_get_sync(vdev->device);
274 ret = vfio_platform_call_reset(vdev, &extra_dbg);
275 if (ret && vdev->reset_required) {
276 dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
277 ret, extra_dbg ? extra_dbg : "");
284 mutex_unlock(&driver_lock);
288 pm_runtime_put(vdev->device);
289 vfio_platform_irq_cleanup(vdev);
291 vfio_platform_regions_cleanup(vdev);
293 mutex_unlock(&driver_lock);
294 module_put(vdev->parent_module);
298 static long vfio_platform_ioctl(struct vfio_device *core_vdev,
299 unsigned int cmd, unsigned long arg)
301 struct vfio_platform_device *vdev =
302 container_of(core_vdev, struct vfio_platform_device, vdev);
306 if (cmd == VFIO_DEVICE_GET_INFO) {
307 struct vfio_device_info info;
309 minsz = offsetofend(struct vfio_device_info, num_irqs);
311 if (copy_from_user(&info, (void __user *)arg, minsz))
314 if (info.argsz < minsz)
317 if (vfio_platform_has_reset(vdev))
318 vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
319 info.flags = vdev->flags;
320 info.num_regions = vdev->num_regions;
321 info.num_irqs = vdev->num_irqs;
323 return copy_to_user((void __user *)arg, &info, minsz) ?
326 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
327 struct vfio_region_info info;
329 minsz = offsetofend(struct vfio_region_info, offset);
331 if (copy_from_user(&info, (void __user *)arg, minsz))
334 if (info.argsz < minsz)
337 if (info.index >= vdev->num_regions)
340 /* map offset to the physical address */
341 info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
342 info.size = vdev->regions[info.index].size;
343 info.flags = vdev->regions[info.index].flags;
345 return copy_to_user((void __user *)arg, &info, minsz) ?
348 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
349 struct vfio_irq_info info;
351 minsz = offsetofend(struct vfio_irq_info, count);
353 if (copy_from_user(&info, (void __user *)arg, minsz))
356 if (info.argsz < minsz)
359 if (info.index >= vdev->num_irqs)
362 info.flags = vdev->irqs[info.index].flags;
363 info.count = vdev->irqs[info.index].count;
365 return copy_to_user((void __user *)arg, &info, minsz) ?
368 } else if (cmd == VFIO_DEVICE_SET_IRQS) {
369 struct vfio_irq_set hdr;
372 size_t data_size = 0;
374 minsz = offsetofend(struct vfio_irq_set, count);
376 if (copy_from_user(&hdr, (void __user *)arg, minsz))
379 ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
380 vdev->num_irqs, &data_size);
385 data = memdup_user((void __user *)(arg + minsz),
388 return PTR_ERR(data);
391 mutex_lock(&vdev->igate);
393 ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
394 hdr.start, hdr.count, data);
395 mutex_unlock(&vdev->igate);
400 } else if (cmd == VFIO_DEVICE_RESET) {
401 return vfio_platform_call_reset(vdev, NULL);
407 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
408 char __user *buf, size_t count,
411 unsigned int done = 0;
415 ioremap(reg->addr, reg->size);
424 if (count >= 4 && !(off % 4)) {
427 val = ioread32(reg->ioaddr + off);
428 if (copy_to_user(buf, &val, 4))
432 } else if (count >= 2 && !(off % 2)) {
435 val = ioread16(reg->ioaddr + off);
436 if (copy_to_user(buf, &val, 2))
443 val = ioread8(reg->ioaddr + off);
444 if (copy_to_user(buf, &val, 1))
462 static ssize_t vfio_platform_read(struct vfio_device *core_vdev,
463 char __user *buf, size_t count, loff_t *ppos)
465 struct vfio_platform_device *vdev =
466 container_of(core_vdev, struct vfio_platform_device, vdev);
467 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
468 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
470 if (index >= vdev->num_regions)
473 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
476 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
477 return vfio_platform_read_mmio(&vdev->regions[index],
479 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
480 return -EINVAL; /* not implemented */
485 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
486 const char __user *buf, size_t count,
489 unsigned int done = 0;
493 ioremap(reg->addr, reg->size);
502 if (count >= 4 && !(off % 4)) {
505 if (copy_from_user(&val, buf, 4))
507 iowrite32(val, reg->ioaddr + off);
510 } else if (count >= 2 && !(off % 2)) {
513 if (copy_from_user(&val, buf, 2))
515 iowrite16(val, reg->ioaddr + off);
521 if (copy_from_user(&val, buf, 1))
523 iowrite8(val, reg->ioaddr + off);
539 static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
540 size_t count, loff_t *ppos)
542 struct vfio_platform_device *vdev =
543 container_of(core_vdev, struct vfio_platform_device, vdev);
544 unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
545 loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
547 if (index >= vdev->num_regions)
550 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
553 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
554 return vfio_platform_write_mmio(&vdev->regions[index],
556 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
557 return -EINVAL; /* not implemented */
562 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
563 struct vm_area_struct *vma)
565 u64 req_len, pgoff, req_start;
567 req_len = vma->vm_end - vma->vm_start;
568 pgoff = vma->vm_pgoff &
569 ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
570 req_start = pgoff << PAGE_SHIFT;
572 if (region.size < PAGE_SIZE || req_start + req_len > region.size)
575 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
576 vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
578 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
579 req_len, vma->vm_page_prot);
582 static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
584 struct vfio_platform_device *vdev =
585 container_of(core_vdev, struct vfio_platform_device, vdev);
588 index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
590 if (vma->vm_end < vma->vm_start)
592 if (!(vma->vm_flags & VM_SHARED))
594 if (index >= vdev->num_regions)
596 if (vma->vm_start & ~PAGE_MASK)
598 if (vma->vm_end & ~PAGE_MASK)
601 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
604 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
605 && (vma->vm_flags & VM_READ))
608 if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
609 && (vma->vm_flags & VM_WRITE))
612 vma->vm_private_data = vdev;
614 if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
615 return vfio_platform_mmap_mmio(vdev->regions[index], vma);
617 else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
618 return -EINVAL; /* not implemented */
623 static const struct vfio_device_ops vfio_platform_ops = {
624 .name = "vfio-platform",
625 .open = vfio_platform_open,
626 .release = vfio_platform_release,
627 .ioctl = vfio_platform_ioctl,
628 .read = vfio_platform_read,
629 .write = vfio_platform_write,
630 .mmap = vfio_platform_mmap,
633 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
638 ret = device_property_read_string(dev, "compatible",
641 dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name);
647 * There can be two kernel build combinations. One build where
648 * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
650 * In the first case, vfio_platform_acpi_probe will return since
651 * acpi_disabled is 1. DT user will not see any kind of messages from
654 * In the second case, both DT and ACPI is compiled in but the system is
655 * booting with any of these combinations.
657 * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
658 * terminates immediately without any messages.
660 * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
661 * valid checks. We cannot claim that this system is DT.
663 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
666 struct iommu_group *group;
669 vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
671 ret = vfio_platform_acpi_probe(vdev, dev);
673 ret = vfio_platform_of_probe(vdev, dev);
680 ret = vfio_platform_get_reset(vdev);
681 if (ret && vdev->reset_required) {
682 dev_err(dev, "No reset function found for device %s\n",
687 group = vfio_iommu_group_get(dev);
689 dev_err(dev, "No IOMMU group for device %s\n", vdev->name);
694 ret = vfio_register_group_dev(&vdev->vdev);
698 mutex_init(&vdev->igate);
700 pm_runtime_enable(dev);
704 vfio_iommu_group_put(group, dev);
706 vfio_platform_put_reset(vdev);
709 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
711 void vfio_platform_remove_common(struct vfio_platform_device *vdev)
713 vfio_unregister_group_dev(&vdev->vdev);
715 pm_runtime_disable(vdev->device);
716 vfio_platform_put_reset(vdev);
717 vfio_iommu_group_put(vdev->vdev.dev->iommu_group, vdev->vdev.dev);
719 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
721 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
723 mutex_lock(&driver_lock);
724 list_add(&node->link, &reset_list);
725 mutex_unlock(&driver_lock);
727 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
729 void vfio_platform_unregister_reset(const char *compat,
730 vfio_platform_reset_fn_t fn)
732 struct vfio_platform_reset_node *iter, *temp;
734 mutex_lock(&driver_lock);
735 list_for_each_entry_safe(iter, temp, &reset_list, link) {
736 if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
737 list_del(&iter->link);
742 mutex_unlock(&driver_lock);
745 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
747 MODULE_VERSION(DRIVER_VERSION);
748 MODULE_LICENSE("GPL v2");
749 MODULE_AUTHOR(DRIVER_AUTHOR);
750 MODULE_DESCRIPTION(DRIVER_DESC);