/* *	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/sched.h>#include <linux/errno.h>#include <linux/pci.h>#include <linux/smp_lock.h>#include <asm/uaccess.h>asmlinkage longsys_pciconfig_read(unsigned long bus, unsigned long dfn,		   unsigned long off, unsigned long len, void *buf){	struct pci_dev *dev;	u8 byte;	u16 word;	u32 dword;	long err, cfg_ret;	err = -EPERM;	if (!capable(CAP_SYS_ADMIN))		goto error;	err = -ENODEV;	dev = pci_find_slot(bus, dfn);	if (!dev)		goto error;	lock_kernel();	switch (len) {	case 1:		cfg_ret = pci_read_config_byte(dev, off, &byte);		break;	case 2:		cfg_ret = pci_read_config_word(dev, off, &word);		break;	case 4:		cfg_ret = pci_read_config_dword(dev, off, &dword);		break;	default:		err = -EINVAL;		unlock_kernel();		goto error;	};	unlock_kernel();	err = -EIO;	if (cfg_ret != PCIBIOS_SUCCESSFUL)		goto error;	switch (len) {	case 1:		err = put_user(byte, (unsigned char *)buf);		break;	case 2:		err = put_user(word, (unsigned short *)buf);		break;	case 4:		err = put_user(dword, (unsigned int *)buf);		break;	};	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 *)buf);		break;	case 2:		put_user(-1, (unsigned short *)buf);		break;	case 4:		put_user(-1, (unsigned int *)buf);		break;	};	return err;}asmlinkage longsys_pciconfig_write(unsigned long bus, unsigned long dfn,		    unsigned long off, unsigned long len, void *buf){	struct pci_dev *dev;	u8 byte;	u16 word;	u32 dword;	int err = 0;	if (!capable(CAP_SYS_ADMIN))		return -EPERM;	if (!pcibios_present())		return -ENOSYS;	dev = pci_find_slot(bus, dfn);	if (!dev)		return -ENODEV;	lock_kernel();	switch(len) {	case 1:		err = get_user(byte, (u8 *)buf);		if (err)			break;		err = pci_write_config_byte(dev, off, byte);		if (err != PCIBIOS_SUCCESSFUL)			err = -EIO;		break;	case 2:		err = get_user(word, (u16 *)buf);		if (err)			break;		err = pci_write_config_word(dev, off, word);		if (err != PCIBIOS_SUCCESSFUL)			err = -EIO;		break;	case 4:		err = get_user(dword, (u32 *)buf);		if (err)			break;		err = pci_write_config_dword(dev, off, dword);		if (err != PCIBIOS_SUCCESSFUL)			err = -EIO;		break;	default:		err = -EINVAL;		break;	};	unlock_kernel();	return err;}