linux/drivers/vfio/platform/vfio_platform_common.c
Antonios Motakis fad4d5b1f0 vfio/platform: support MMAP of MMIO regions
Allow to memory map the MMIO regions of the device so userspace can
directly access them. PIO regions are not being handled at this point.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-16 14:08:48 -06:00

453 lines
9.9 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/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include "vfio_platform_private.h"
static DEFINE_MUTEX(driver_lock);
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 void vfio_platform_release(void *device_data)
{
struct vfio_platform_device *vdev = device_data;
mutex_lock(&driver_lock);
if (!(--vdev->refcnt)) {
vfio_platform_regions_cleanup(vdev);
}
mutex_unlock(&driver_lock);
module_put(THIS_MODULE);
}
static int vfio_platform_open(void *device_data)
{
struct vfio_platform_device *vdev = device_data;
int ret;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
mutex_lock(&driver_lock);
if (!vdev->refcnt) {
ret = vfio_platform_regions_init(vdev);
if (ret)
goto err_reg;
}
vdev->refcnt++;
mutex_unlock(&driver_lock);
return 0;
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;
info.flags = vdev->flags;
info.num_regions = vdev->num_regions;
info.num_irqs = 0;
return copy_to_user((void __user *)arg, &info, minsz);
} 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);
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
return -EINVAL;
else if (cmd == VFIO_DEVICE_SET_IRQS)
return -EINVAL;
else if (cmd == VFIO_DEVICE_RESET)
return -EINVAL;
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,
};
int vfio_platform_probe_common(struct vfio_platform_device *vdev,
struct device *dev)
{
struct iommu_group *group;
int ret;
if (!vdev)
return -EINVAL;
group = iommu_group_get(dev);
if (!group) {
pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
return -EINVAL;
}
ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
if (ret) {
iommu_group_put(group);
return ret;
}
return 0;
}
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)
iommu_group_put(dev->iommu_group);
return vdev;
}
EXPORT_SYMBOL_GPL(vfio_platform_remove_common);