// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 - Virtual Open Systems
* Author: Antonios Motakis <[email protected]>
*/
#define dev_fmt(fmt) "VFIO: " fmt
#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 <[email protected]>"
#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) {
dev_err(dev, "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 device *dev = vdev->device;
acpi_handle handle = ACPI_HANDLE(dev);
acpi_status acpi_ret;
acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, NULL);
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_ACCOUNT);
if (!vdev->regions)
return -ENOMEM;
for (i = 0; i < cnt; i++) {
struct resource *res =
vdev->get_resource(vdev, i);
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;
}
void vfio_platform_close_device(struct vfio_device *core_vdev)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
const char *extra_dbg = NULL;
int ret;
ret = vfio_platform_call_reset(vdev, &extra_dbg);
if (WARN_ON(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 : "");
}
pm_runtime_put(vdev->device);
vfio_platform_regions_cleanup(vdev);
vfio_platform_irq_cleanup(vdev);
}
EXPORT_SYMBOL_GPL(vfio_platform_close_device);
int vfio_platform_open_device(struct vfio_device *core_vdev)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
const char *extra_dbg = NULL;
int ret;
ret = vfio_platform_regions_init(vdev);
if (ret)
return ret;
ret = vfio_platform_irq_init(vdev);
if (ret)
goto err_irq;
ret = pm_runtime_get_sync(vdev->device);
if (ret < 0)
goto err_rst;
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;
}
return 0;
err_rst:
pm_runtime_put(vdev->device);
vfio_platform_irq_cleanup(vdev);
err_irq:
vfio_platform_regions_cleanup(vdev);
return ret;
}
EXPORT_SYMBOL_GPL(vfio_platform_open_device);
long vfio_platform_ioctl(struct vfio_device *core_vdev,
unsigned int cmd, unsigned long arg)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
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;
}
EXPORT_SYMBOL_GPL(vfio_platform_ioctl);
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(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;
}
ssize_t vfio_platform_read(struct vfio_device *core_vdev,
char __user *buf, size_t count, loff_t *ppos)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
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;
}
EXPORT_SYMBOL_GPL(vfio_platform_read);
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(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;
}
ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
size_t count, loff_t *ppos)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
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;
}
EXPORT_SYMBOL_GPL(vfio_platform_write);
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);
}
int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
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;
}
EXPORT_SYMBOL_GPL(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)
dev_err(dev, "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_init_common(struct vfio_platform_device *vdev)
{
int ret;
struct device *dev = vdev->vdev.dev;
ret = vfio_platform_acpi_probe(vdev, dev);
if (ret)
ret = vfio_platform_of_probe(vdev, dev);
if (ret)
return ret;
vdev->device = dev;
mutex_init(&vdev->igate);
ret = vfio_platform_get_reset(vdev);
if (ret && vdev->reset_required) {
dev_err(dev, "No reset function found for device %s\n",
vdev->name);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(vfio_platform_init_common);
void vfio_platform_release_common(struct vfio_platform_device *vdev)
{
vfio_platform_put_reset(vdev);
}
EXPORT_SYMBOL_GPL(vfio_platform_release_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);
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