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vfio-pci: Cleanup BAR access

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We can actually handle MMIO and I/O port from the same access function
since PCI already does abstraction of this.  The ROM BAR only requires
a minor difference, so it gets included too.  vfio_pci_config_readwrite
gets renamed for consistency.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Alex Williamson 2013-02-14 14:02:12 -07:00
parent 5b279a11d3
commit 906ee99dd2
4 changed files with 113 additions and 213 deletions
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26
drivers/vfio/pci/vfio_pci.c
View File

@ -371,31 +371,21 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
{
unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
struct vfio_pci_device *vdev = device_data;
struct pci_dev *pdev = vdev->pdev;
if (index >= VFIO_PCI_NUM_REGIONS)
return -EINVAL;
switch (index) {
case VFIO_PCI_CONFIG_REGION_INDEX:
return vfio_pci_config_readwrite(vdev, buf, count,
ppos, iswrite);
return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
case VFIO_PCI_ROM_REGION_INDEX:
if (iswrite)
return -EINVAL;
return vfio_pci_mem_readwrite(vdev, buf, count, ppos, false);
return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
{
unsigned long flags = pci_resource_flags(pdev, index);
if (flags & IORESOURCE_IO)
return vfio_pci_io_readwrite(vdev, buf, count,
ppos, iswrite);
if (flags & IORESOURCE_MEM)
return vfio_pci_mem_readwrite(vdev, buf, count,
ppos, iswrite);
}
return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
}
return -EINVAL;
@ -404,13 +394,19 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
static ssize_t vfio_pci_read(void *device_data, char __user *buf,
size_t count, loff_t *ppos)
{
if (!count)
return 0;
return vfio_pci_rw(device_data, buf, count, ppos, false);
}
static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
size_t count, loff_t *ppos)
{
return vfio_pci_rw(device_data, buf, count, ppos, true);
if (!count)
return 0;
return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
}
static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)

5
drivers/vfio/pci/vfio_pci_config.c
View File

@ -1501,9 +1501,8 @@ static ssize_t vfio_config_do_rw(struct vfio_pci_device *vdev, char __user *buf,
return ret;
}
ssize_t vfio_pci_config_readwrite(struct vfio_pci_device *vdev,
char __user *buf, size_t count,
loff_t *ppos, bool iswrite)
ssize_t vfio_pci_config_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
size_t done = 0;
int ret = 0;

15
drivers/vfio/pci/vfio_pci_private.h
View File

@ -70,15 +70,12 @@ extern int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev,
uint32_t flags, unsigned index,
unsigned start, unsigned count, void *data);
extern ssize_t vfio_pci_config_readwrite(struct vfio_pci_device *vdev,
char __user *buf, size_t count,
loff_t *ppos, bool iswrite);
extern ssize_t vfio_pci_mem_readwrite(struct vfio_pci_device *vdev,
char __user *buf, size_t count,
loff_t *ppos, bool iswrite);
extern ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev,
char __user *buf, size_t count,
loff_t *ppos, bool iswrite);
extern ssize_t vfio_pci_config_rw(struct vfio_pci_device *vdev,
char __user *buf, size_t count,
loff_t *ppos, bool iswrite);
extern ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite);
extern int vfio_pci_init_perm_bits(void);
extern void vfio_pci_uninit_perm_bits(void);

280
drivers/vfio/pci/vfio_pci_rdwr.c
View File

@ -20,205 +20,57 @@
#include "vfio_pci_private.h"
/* I/O Port BAR access */
ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
struct pci_dev *pdev = vdev->pdev;
loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
void __iomem *io;
size_t done = 0;
if (!pci_resource_start(pdev, bar))
return -EINVAL;
if (pos + count > pci_resource_len(pdev, bar))
return -EINVAL;
if (!vdev->barmap[bar]) {
int ret;
ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
if (ret)
return ret;
vdev->barmap[bar] = pci_iomap(pdev, bar, 0);
if (!vdev->barmap[bar]) {
pci_release_selected_regions(pdev, 1 << bar);
return -EINVAL;
}
}
io = vdev->barmap[bar];
while (count) {
int filled;
if (count >= 3 && !(pos % 4)) {
__le32 val;
if (iswrite) {
if (copy_from_user(&val, buf, 4))
return -EFAULT;
iowrite32(le32_to_cpu(val), io + pos);
} else {
val = cpu_to_le32(ioread32(io + pos));
if (copy_to_user(buf, &val, 4))
return -EFAULT;
}
filled = 4;
} else if ((pos % 2) == 0 && count >= 2) {
__le16 val;
if (iswrite) {
if (copy_from_user(&val, buf, 2))
return -EFAULT;
iowrite16(le16_to_cpu(val), io + pos);
} else {
val = cpu_to_le16(ioread16(io + pos));
if (copy_to_user(buf, &val, 2))
return -EFAULT;
}
filled = 2;
} else {
u8 val;
if (iswrite) {
if (copy_from_user(&val, buf, 1))
return -EFAULT;
iowrite8(val, io + pos);
} else {
val = ioread8(io + pos);
if (copy_to_user(buf, &val, 1))
return -EFAULT;
}
filled = 1;
}
count -= filled;
done += filled;
buf += filled;
pos += filled;
}
*ppos += done;
return done;
}
/*
* MMIO BAR access
* We handle two excluded ranges here as well, if the user tries to read
* the ROM beyond what PCI tells us is available or the MSI-X table region,
* we return 0xFF and writes are dropped.
* Read or write from an __iomem region (MMIO or I/O port) with an excluded
* range which is inaccessible. The excluded range drops writes and fills
* reads with -1. This is intended for handling MSI-X vector tables and
* leftover space for ROM BARs.
*/
ssize_t vfio_pci_mem_readwrite(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
static ssize_t do_io_rw(void __iomem *io, char __user *buf,
loff_t off, size_t count, size_t x_start,
size_t x_end, bool iswrite)
{
struct pci_dev *pdev = vdev->pdev;
loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
void __iomem *io;
resource_size_t end;
size_t done = 0;
size_t x_start = 0, x_end = 0; /* excluded range */
if (!pci_resource_start(pdev, bar))
return -EINVAL;
end = pci_resource_len(pdev, bar);
if (pos > end)
return -EINVAL;
if (pos == end)
return 0;
if (pos + count > end)
count = end - pos;
if (bar == PCI_ROM_RESOURCE) {
io = pci_map_rom(pdev, &x_start);
x_end = end;
} else {
if (!vdev->barmap[bar]) {
int ret;
ret = pci_request_selected_regions(pdev, 1 << bar,
"vfio");
if (ret)
return ret;
vdev->barmap[bar] = pci_iomap(pdev, bar, 0);
if (!vdev->barmap[bar]) {
pci_release_selected_regions(pdev, 1 << bar);
return -EINVAL;
}
}
io = vdev->barmap[bar];
if (bar == vdev->msix_bar) {
x_start = vdev->msix_offset;
x_end = vdev->msix_offset + vdev->msix_size;
}
}
if (!io)
return -EINVAL;
ssize_t done = 0;
while (count) {
size_t fillable, filled;
if (pos < x_start)
fillable = x_start - pos;
else if (pos >= x_end)
fillable = end - pos;
if (off < x_start)
fillable = min(count, (size_t)(x_start - off));
else if (off >= x_end)
fillable = count;
else
fillable = 0;
if (fillable >= 4 && !(pos % 4) && (count >= 4)) {
if (fillable >= 4 && !(off % 4)) {
__le32 val;
if (iswrite) {
if (copy_from_user(&val, buf, 4))
goto out;
return -EFAULT;
iowrite32(le32_to_cpu(val), io + pos);
iowrite32(le32_to_cpu(val), io + off);
} else {
val = cpu_to_le32(ioread32(io + pos));
val = cpu_to_le32(ioread32(io + off));
if (copy_to_user(buf, &val, 4))
goto out;
return -EFAULT;
}
filled = 4;
} else if (fillable >= 2 && !(pos % 2) && (count >= 2)) {
} else if (fillable >= 2 && !(off % 2)) {
__le16 val;
if (iswrite) {
if (copy_from_user(&val, buf, 2))
goto out;
return -EFAULT;
iowrite16(le16_to_cpu(val), io + pos);
iowrite16(le16_to_cpu(val), io + off);
} else {
val = cpu_to_le16(ioread16(io + pos));
val = cpu_to_le16(ioread16(io + off));
if (copy_to_user(buf, &val, 2))
goto out;
return -EFAULT;
}
filled = 2;
@ -227,43 +79,99 @@ ssize_t vfio_pci_mem_readwrite(struct vfio_pci_device *vdev, char __user *buf,
if (iswrite) {
if (copy_from_user(&val, buf, 1))
goto out;
return -EFAULT;
iowrite8(val, io + pos);
iowrite8(val, io + off);
} else {
val = ioread8(io + pos);
val = ioread8(io + off);
if (copy_to_user(buf, &val, 1))
goto out;
return -EFAULT;
}
filled = 1;
} else {
/* Drop writes, fill reads with FF */
filled = min((size_t)(x_end - pos), count);
/* Fill reads with -1, drop writes */
filled = min(count, (size_t)(x_end - off));
if (!iswrite) {
char val = 0xFF;
u8 val = 0xFF;
size_t i;
for (i = 0; i < filled; i++) {
if (put_user(val, buf + i))
goto out;
}
for (i = 0; i < filled; i++)
if (copy_to_user(buf + i, &val, 1))
return -EFAULT;
}
}
count -= filled;
done += filled;
off += filled;
buf += filled;
pos += filled;
}
*ppos += done;
return done;
}
ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
struct pci_dev *pdev = vdev->pdev;
loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
size_t x_start = 0, x_end = 0;
resource_size_t end;
void __iomem *io;
ssize_t done;
if (!pci_resource_start(pdev, bar))
return -EINVAL;
end = pci_resource_len(pdev, bar);
if (pos >= end)
return -EINVAL;
count = min(count, (size_t)(end - pos));
if (bar == PCI_ROM_RESOURCE) {
/*
* The ROM can fill less space than the BAR, so we start the
* excluded range at the end of the actual ROM. This makes
* filling large ROM BARs much faster.
*/
io = pci_map_rom(pdev, &x_start);
if (!io)
return -ENOMEM;
x_end = end;
} else if (!vdev->barmap[bar]) {
int ret;
ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
if (ret)
return ret;
io = pci_iomap(pdev, bar, 0);
if (!io) {
pci_release_selected_regions(pdev, 1 << bar);
return -ENOMEM;
}
vdev->barmap[bar] = io;
} else
io = vdev->barmap[bar];
if (bar == vdev->msix_bar) {
x_start = vdev->msix_offset;
x_end = vdev->msix_offset + vdev->msix_size;
}
done = do_io_rw(io, buf, pos, count, x_start, x_end, iswrite);
if (done >= 0)
*ppos += done;
out:
if (bar == PCI_ROM_RESOURCE)
pci_unmap_rom(pdev, io);
return count ? -EFAULT : done;
return done;
}