linux/drivers/vfio/platform/vfio_platform_common.c
Geert Uytterhoeven 415eb9fc0e vfio: platform: Fix using devices in PM Domains
If a device is part of a PM Domain (e.g. power and/or clock domain), its
power state is managed using Runtime PM.  Without Runtime PM, the device
may not be powered up or clocked, causing subtle failures, crashes, or
system lock-ups when the device is accessed by the guest.

Fix this by adding Runtime PM support, powering the device when the VFIO
device is opened by the guest.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08 10:24:37 -06:00

758 lines
17 KiB
C

/*
* Copyright (C) 2013 - Virtual Open Systems
* Author: Antonios Motakis <a.motakis@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/acpi.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include "vfio_platform_private.h"
#define DRIVER_VERSION "0.10"
#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>"
#define DRIVER_DESC "VFIO platform base module"
#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
static LIST_HEAD(reset_list);
static DEFINE_MUTEX(driver_lock);
static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
struct module **module)
{
struct vfio_platform_reset_node *iter;
vfio_platform_reset_fn_t reset_fn = NULL;
mutex_lock(&driver_lock);
list_for_each_entry(iter, &reset_list, link) {
if (!strcmp(iter->compat, compat) &&
try_module_get(iter->owner)) {
*module = iter->owner;
reset_fn = iter->of_reset;
break;
}
}
mutex_unlock(&driver_lock);
return reset_fn;
}
static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
struct device *dev)
{
struct acpi_device *adev;
if (acpi_disabled)
return -ENOENT;
adev = ACPI_COMPANION(dev);
if (!adev) {
pr_err("VFIO: ACPI companion device not found for %s\n",
vdev->name);
return -ENODEV;
}
#ifdef CONFIG_ACPI
vdev->acpihid = acpi_device_hid(adev);
#endif
return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
}
static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
const char **extra_dbg)
{
#ifdef CONFIG_ACPI
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct device *dev = vdev->device;
acpi_handle handle = ACPI_HANDLE(dev);
acpi_status acpi_ret;
acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
if (ACPI_FAILURE(acpi_ret)) {
if (extra_dbg)
*extra_dbg = acpi_format_exception(acpi_ret);
return -EINVAL;
}
return 0;
#else
return -ENOENT;
#endif
}
static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
{
#ifdef CONFIG_ACPI
struct device *dev = vdev->device;
acpi_handle handle = ACPI_HANDLE(dev);
return acpi_has_method(handle, "_RST");
#else
return false;
#endif
}
static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
{
if (VFIO_PLATFORM_IS_ACPI(vdev))
return vfio_platform_acpi_has_reset(vdev);
return vdev->of_reset ? true : false;
}
static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
{
if (VFIO_PLATFORM_IS_ACPI(vdev))
return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
&vdev->reset_module);
if (!vdev->of_reset) {
request_module("vfio-reset:%s", vdev->compat);
vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
&vdev->reset_module);
}
return vdev->of_reset ? 0 : -ENOENT;
}
static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
{
if (VFIO_PLATFORM_IS_ACPI(vdev))
return;
if (vdev->of_reset)
module_put(vdev->reset_module);
}
static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
{
int cnt = 0, i;
while (vdev->get_resource(vdev, cnt))
cnt++;
vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
GFP_KERNEL);
if (!vdev->regions)
return -ENOMEM;
for (i = 0; i < cnt; i++) {
struct resource *res =
vdev->get_resource(vdev, i);
if (!res)
goto err;
vdev->regions[i].addr = res->start;
vdev->regions[i].size = resource_size(res);
vdev->regions[i].flags = 0;
switch (resource_type(res)) {
case IORESOURCE_MEM:
vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
if (!(res->flags & IORESOURCE_READONLY))
vdev->regions[i].flags |=
VFIO_REGION_INFO_FLAG_WRITE;
/*
* Only regions addressed with PAGE granularity may be
* MMAPed securely.
*/
if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
!(vdev->regions[i].size & ~PAGE_MASK))
vdev->regions[i].flags |=
VFIO_REGION_INFO_FLAG_MMAP;
break;
case IORESOURCE_IO:
vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
break;
default:
goto err;
}
}
vdev->num_regions = cnt;
return 0;
err:
kfree(vdev->regions);
return -EINVAL;
}
static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
{
int i;
for (i = 0; i < vdev->num_regions; i++)
iounmap(vdev->regions[i].ioaddr);
vdev->num_regions = 0;
kfree(vdev->regions);
}
static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
const char **extra_dbg)
{
if (VFIO_PLATFORM_IS_ACPI(vdev)) {
dev_info(vdev->device, "reset\n");
return vfio_platform_acpi_call_reset(vdev, extra_dbg);
} else if (vdev->of_reset) {
dev_info(vdev->device, "reset\n");
return vdev->of_reset(vdev);
}
dev_warn(vdev->device, "no reset function found!\n");
return -EINVAL;
}
static void vfio_platform_release(void *device_data)
{
struct vfio_platform_device *vdev = device_data;
mutex_lock(&driver_lock);
if (!(--vdev->refcnt)) {
const char *extra_dbg = NULL;
int ret;
ret = vfio_platform_call_reset(vdev, &extra_dbg);
if (ret && vdev->reset_required) {
dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
ret, extra_dbg ? extra_dbg : "");
WARN_ON(1);
}
pm_runtime_put(vdev->device);
vfio_platform_regions_cleanup(vdev);
vfio_platform_irq_cleanup(vdev);
}
mutex_unlock(&driver_lock);
module_put(vdev->parent_module);
}
static int vfio_platform_open(void *device_data)
{
struct vfio_platform_device *vdev = device_data;
int ret;
if (!try_module_get(vdev->parent_module))
return -ENODEV;
mutex_lock(&driver_lock);
if (!vdev->refcnt) {
const char *extra_dbg = NULL;
ret = vfio_platform_regions_init(vdev);
if (ret)
goto err_reg;
ret = vfio_platform_irq_init(vdev);
if (ret)
goto err_irq;
ret = pm_runtime_get_sync(vdev->device);
if (ret < 0)
goto err_pm;
ret = vfio_platform_call_reset(vdev, &extra_dbg);
if (ret && vdev->reset_required) {
dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
ret, extra_dbg ? extra_dbg : "");
goto err_rst;
}
}
vdev->refcnt++;
mutex_unlock(&driver_lock);
return 0;
err_rst:
pm_runtime_put(vdev->device);
err_pm:
vfio_platform_irq_cleanup(vdev);
err_irq:
vfio_platform_regions_cleanup(vdev);
err_reg:
mutex_unlock(&driver_lock);
module_put(THIS_MODULE);
return ret;
}
static long vfio_platform_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
struct vfio_platform_device *vdev = device_data;
unsigned long minsz;
if (cmd == VFIO_DEVICE_GET_INFO) {
struct vfio_device_info info;
minsz = offsetofend(struct vfio_device_info, num_irqs);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
if (vfio_platform_has_reset(vdev))
vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
info.flags = vdev->flags;
info.num_regions = vdev->num_regions;
info.num_irqs = vdev->num_irqs;
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct vfio_region_info info;
minsz = offsetofend(struct vfio_region_info, offset);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
if (info.index >= vdev->num_regions)
return -EINVAL;
/* map offset to the physical address */
info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
info.size = vdev->regions[info.index].size;
info.flags = vdev->regions[info.index].flags;
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
minsz = offsetofend(struct vfio_irq_info, count);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
if (info.index >= vdev->num_irqs)
return -EINVAL;
info.flags = vdev->irqs[info.index].flags;
info.count = vdev->irqs[info.index].count;
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;
u8 *data = NULL;
int ret = 0;
size_t data_size = 0;
minsz = offsetofend(struct vfio_irq_set, count);
if (copy_from_user(&hdr, (void __user *)arg, minsz))
return -EFAULT;
ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
vdev->num_irqs, &data_size);
if (ret)
return ret;
if (data_size) {
data = memdup_user((void __user *)(arg + minsz),
data_size);
if (IS_ERR(data))
return PTR_ERR(data);
}
mutex_lock(&vdev->igate);
ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
hdr.start, hdr.count, data);
mutex_unlock(&vdev->igate);
kfree(data);
return ret;
} else if (cmd == VFIO_DEVICE_RESET) {
return vfio_platform_call_reset(vdev, NULL);
}
return -ENOTTY;
}
static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
char __user *buf, size_t count,
loff_t off)
{
unsigned int done = 0;
if (!reg->ioaddr) {
reg->ioaddr =
ioremap_nocache(reg->addr, reg->size);
if (!reg->ioaddr)
return -ENOMEM;
}
while (count) {
size_t filled;
if (count >= 4 && !(off % 4)) {
u32 val;
val = ioread32(reg->ioaddr + off);
if (copy_to_user(buf, &val, 4))
goto err;
filled = 4;
} else if (count >= 2 && !(off % 2)) {
u16 val;
val = ioread16(reg->ioaddr + off);
if (copy_to_user(buf, &val, 2))
goto err;
filled = 2;
} else {
u8 val;
val = ioread8(reg->ioaddr + off);
if (copy_to_user(buf, &val, 1))
goto err;
filled = 1;
}
count -= filled;
done += filled;
off += filled;
buf += filled;
}
return done;
err:
return -EFAULT;
}
static ssize_t vfio_platform_read(void *device_data, char __user *buf,
size_t count, loff_t *ppos)
{
struct vfio_platform_device *vdev = device_data;
unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
if (index >= vdev->num_regions)
return -EINVAL;
if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
return -EINVAL;
if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
return vfio_platform_read_mmio(&vdev->regions[index],
buf, count, off);
else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
return -EINVAL; /* not implemented */
return -EINVAL;
}
static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
const char __user *buf, size_t count,
loff_t off)
{
unsigned int done = 0;
if (!reg->ioaddr) {
reg->ioaddr =
ioremap_nocache(reg->addr, reg->size);
if (!reg->ioaddr)
return -ENOMEM;
}
while (count) {
size_t filled;
if (count >= 4 && !(off % 4)) {
u32 val;
if (copy_from_user(&val, buf, 4))
goto err;
iowrite32(val, reg->ioaddr + off);
filled = 4;
} else if (count >= 2 && !(off % 2)) {
u16 val;
if (copy_from_user(&val, buf, 2))
goto err;
iowrite16(val, reg->ioaddr + off);
filled = 2;
} else {
u8 val;
if (copy_from_user(&val, buf, 1))
goto err;
iowrite8(val, reg->ioaddr + off);
filled = 1;
}
count -= filled;
done += filled;
off += filled;
buf += filled;
}
return done;
err:
return -EFAULT;
}
static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
size_t count, loff_t *ppos)
{
struct vfio_platform_device *vdev = device_data;
unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
if (index >= vdev->num_regions)
return -EINVAL;
if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
return -EINVAL;
if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
return vfio_platform_write_mmio(&vdev->regions[index],
buf, count, off);
else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
return -EINVAL; /* not implemented */
return -EINVAL;
}
static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
struct vm_area_struct *vma)
{
u64 req_len, pgoff, req_start;
req_len = vma->vm_end - vma->vm_start;
pgoff = vma->vm_pgoff &
((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
req_start = pgoff << PAGE_SHIFT;
if (region.size < PAGE_SIZE || req_start + req_len > region.size)
return -EINVAL;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
req_len, vma->vm_page_prot);
}
static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
{
struct vfio_platform_device *vdev = device_data;
unsigned int index;
index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
if (vma->vm_end < vma->vm_start)
return -EINVAL;
if (!(vma->vm_flags & VM_SHARED))
return -EINVAL;
if (index >= vdev->num_regions)
return -EINVAL;
if (vma->vm_start & ~PAGE_MASK)
return -EINVAL;
if (vma->vm_end & ~PAGE_MASK)
return -EINVAL;
if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
return -EINVAL;
if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
&& (vma->vm_flags & VM_READ))
return -EINVAL;
if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
&& (vma->vm_flags & VM_WRITE))
return -EINVAL;
vma->vm_private_data = vdev;
if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
return vfio_platform_mmap_mmio(vdev->regions[index], vma);
else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
return -EINVAL; /* not implemented */
return -EINVAL;
}
static const struct vfio_device_ops vfio_platform_ops = {
.name = "vfio-platform",
.open = vfio_platform_open,
.release = vfio_platform_release,
.ioctl = vfio_platform_ioctl,
.read = vfio_platform_read,
.write = vfio_platform_write,
.mmap = vfio_platform_mmap,
};
static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
struct device *dev)
{
int ret;
ret = device_property_read_string(dev, "compatible",
&vdev->compat);
if (ret)
pr_err("VFIO: Cannot retrieve compat for %s\n", vdev->name);
return ret;
}
/*
* There can be two kernel build combinations. One build where
* ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
*
* In the first case, vfio_platform_acpi_probe will return since
* acpi_disabled is 1. DT user will not see any kind of messages from
* ACPI.
*
* In the second case, both DT and ACPI is compiled in but the system is
* booting with any of these combinations.
*
* If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
* terminates immediately without any messages.
*
* If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
* valid checks. We cannot claim that this system is DT.
*/
int vfio_platform_probe_common(struct vfio_platform_device *vdev,
struct device *dev)
{
struct iommu_group *group;
int ret;
if (!vdev)
return -EINVAL;
ret = vfio_platform_acpi_probe(vdev, dev);
if (ret)
ret = vfio_platform_of_probe(vdev, dev);
if (ret)
return ret;
vdev->device = dev;
ret = vfio_platform_get_reset(vdev);
if (ret && vdev->reset_required) {
pr_err("VFIO: No reset function found for device %s\n",
vdev->name);
return ret;
}
group = vfio_iommu_group_get(dev);
if (!group) {
pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
ret = -EINVAL;
goto put_reset;
}
ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
if (ret)
goto put_iommu;
mutex_init(&vdev->igate);
pm_runtime_enable(vdev->device);
return 0;
put_iommu:
vfio_iommu_group_put(group, dev);
put_reset:
vfio_platform_put_reset(vdev);
return ret;
}
EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
{
struct vfio_platform_device *vdev;
vdev = vfio_del_group_dev(dev);
if (vdev) {
pm_runtime_disable(vdev->device);
vfio_platform_put_reset(vdev);
vfio_iommu_group_put(dev->iommu_group, dev);
}
return vdev;
}
EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
{
mutex_lock(&driver_lock);
list_add(&node->link, &reset_list);
mutex_unlock(&driver_lock);
}
EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
void vfio_platform_unregister_reset(const char *compat,
vfio_platform_reset_fn_t fn)
{
struct vfio_platform_reset_node *iter, *temp;
mutex_lock(&driver_lock);
list_for_each_entry_safe(iter, temp, &reset_list, link) {
if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
list_del(&iter->link);
break;
}
}
mutex_unlock(&driver_lock);
}
EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);