diff options
Diffstat (limited to 'drivers/pci/syscall.c')
| -rw-r--r-- | drivers/pci/syscall.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c new file mode 100644 index 000000000..b91c4da68 --- /dev/null +++ b/drivers/pci/syscall.c @@ -0,0 +1,136 @@ +/* + * pci_syscall.c + * + * For architectures where we want to allow direct access + * to the PCI config stuff - it would probably be preferable + * on PCs too, but there people just do it by hand with the + * magic northbridge registers.. + */ + +#include <linux/errno.h> +#include <linux/pci.h> +#include <linux/syscalls.h> +#include <asm/uaccess.h> +#include "pci.h" + +SYSCALL_DEFINE5(pciconfig_read, 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; + long err; + long cfg_ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + err = -ENODEV; + dev = pci_get_bus_and_slot(bus, dfn); + if (!dev) + goto error; + + switch (len) { + case 1: + cfg_ret = pci_user_read_config_byte(dev, off, &byte); + break; + case 2: + cfg_ret = pci_user_read_config_word(dev, off, &word); + break; + case 4: + cfg_ret = pci_user_read_config_dword(dev, off, &dword); + break; + default: + err = -EINVAL; + goto error; + } + + err = -EIO; + if (cfg_ret != PCIBIOS_SUCCESSFUL) + goto error; + + switch (len) { + case 1: + err = put_user(byte, (unsigned char __user *)buf); + break; + case 2: + err = put_user(word, (unsigned short __user *)buf); + break; + case 4: + err = put_user(dword, (unsigned int __user *)buf); + break; + } + pci_dev_put(dev); + return err; + +error: + /* ??? XFree86 doesn't even check the return value. They + just look for 0xffffffff in the output, since that's what + they get instead of a machine check on x86. */ + switch (len) { + case 1: + put_user(-1, (unsigned char __user *)buf); + break; + case 2: + put_user(-1, (unsigned short __user *)buf); + break; + case 4: + put_user(-1, (unsigned int __user *)buf); + break; + } + pci_dev_put(dev); + return err; +} + +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)) + 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; +} |