SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
unsigned long, off, unsigned long, len, void __user *, buf)
{
struct pci_dev *dev;
u8 byte;
u16 word;
u32 dword;
int err = 0;
if (!capable(CAP_SYS_ADMIN) || (get_securelevel() > 0))
return -EPERM;
dev = pci_get_bus_and_slot(bus, dfn);
if (!dev)
return -ENODEV;
switch (len) {
case 1:
err = get_user(byte, (u8 __user *)buf);
if (err)
break;
err = pci_user_write_config_byte(dev, off, byte);
if (err != PCIBIOS_SUCCESSFUL)
err = -EIO;
break;
case 2:
err = get_user(word, (u16 __user *)buf);
if (err)
break;
err = pci_user_write_config_word(dev, off, word);
if (err != PCIBIOS_SUCCESSFUL)
err = -EIO;
break;
case 4:
err = get_user(dword, (u32 __user *)buf);
if (err)
break;
err = pci_user_write_config_dword(dev, off, dword);
if (err != PCIBIOS_SUCCESSFUL)
err = -EIO;
break;
default:
err = -EINVAL;
break;
}
pci_dev_put(dev);
return err;
}
static ssize_t
proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, loff_t *ppos)
{
struct inode *ino = file_inode(file);
struct pci_dev *dev = PDE_DATA(ino);
int pos = *ppos;
int size = dev->cfg_size;
int cnt;
if (pos >= size)
return 0;
if (nbytes >= size)
nbytes = size;
if (pos + nbytes > size)
nbytes = size - pos;
cnt = nbytes;
if (!access_ok(VERIFY_READ, buf, cnt))
return -EINVAL;
pci_config_pm_runtime_get(dev);
if ((pos & 1) && cnt) {
unsigned char val;
__get_user(val, buf);
pci_user_write_config_byte(dev, pos, val);
buf++;
pos++;
cnt--;
}
if ((pos & 3) && cnt > 2) {
__le16 val;
__get_user(val, (__le16 __user *) buf);
pci_user_write_config_word(dev, pos, le16_to_cpu(val));
buf += 2;
pos += 2;
cnt -= 2;
}
while (cnt >= 4) {
__le32 val;
__get_user(val, (__le32 __user *) buf);
pci_user_write_config_dword(dev, pos, le32_to_cpu(val));
buf += 4;
pos += 4;
cnt -= 4;
}
if (cnt >= 2) {
__le16 val;
__get_user(val, (__le16 __user *) buf);
pci_user_write_config_word(dev, pos, le16_to_cpu(val));
buf += 2;
pos += 2;
cnt -= 2;
}
if (cnt) {
unsigned char val;
__get_user(val, buf);
pci_user_write_config_byte(dev, pos, val);
buf++;
pos++;
cnt--;
}
pci_config_pm_runtime_put(dev);
*ppos = pos;
i_size_write(ino, dev->cfg_size);
return nbytes;
}
