[linux-2.6-block.git] / drivers / pci / syscall.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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 <linux/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_domain_bus_and_slot(0, 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_domain_bus_and_slot(0, 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;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4	2	/*
df62ab5e BH	3	* For architectures where we want to allow direct access to the PCI config
	4	* stuff - it would probably be preferable on PCs too, but there people
	5	* just do it by hand with the magic northbridge registers.
1da177e4 LT	6	*/
1da177e4 LT	7
1da177e4 LT	8	#include <linux/errno.h>
1da177e4 LT	9	#include <linux/pci.h>
1da177e4	10	#include <linux/syscalls.h>
7c0f6ba6	11	#include <linux/uaccess.h>
e04b0ea2	12	#include "pci.h"
1da177e4	13
c4ea37c2 HC	14	SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
c4ea37c2 HC	15	unsigned long, off, unsigned long, len, void __user *, buf)
1da177e4 LT	16	{
	17	struct pci_dev *dev;
	18	u8 byte;
	19	u16 word;
	20	u32 dword;
e4585da2 AC	21	long err;
e4585da2 AC	22	long cfg_ret;
1da177e4	23
1da177e4	24	if (!capable(CAP_SYS_ADMIN))
e4585da2	25	return -EPERM;
1da177e4 LT	26
1da177e4 LT	27	err = -ENODEV;
39c94652	28	dev = pci_get_domain_bus_and_slot(0, bus, dfn);
1da177e4 LT	29	if (!dev)
	30	goto error;
	31
1da177e4 LT	32	switch (len) {
1da177e4 LT	33	case 1:
e04b0ea2	34	cfg_ret = pci_user_read_config_byte(dev, off, &byte);
1da177e4 LT	35	break;
1da177e4 LT	36	case 2:
e04b0ea2	37	cfg_ret = pci_user_read_config_word(dev, off, &word);
1da177e4 LT	38	break;
1da177e4 LT	39	case 4:
e04b0ea2	40	cfg_ret = pci_user_read_config_dword(dev, off, &dword);
1da177e4 LT	41	break;
	42	default:
	43	err = -EINVAL;
1da177e4	44	goto error;
f7625980	45	}
1da177e4 LT	46
	47	err = -EIO;
	48	if (cfg_ret != PCIBIOS_SUCCESSFUL)
	49	goto error;
	50
	51	switch (len) {
	52	case 1:
	53	err = put_user(byte, (unsigned char __user *)buf);
	54	break;
	55	case 2:
	56	err = put_user(word, (unsigned short __user *)buf);
	57	break;
	58	case 4:
	59	err = put_user(dword, (unsigned int __user *)buf);
	60	break;
e4585da2 AC	61	}
e4585da2 AC	62	pci_dev_put(dev);
1da177e4 LT	63	return err;
	64
	65	error:
	66	/* ??? XFree86 doesn't even check the return value. They
	67	just look for 0xffffffff in the output, since that's what
	68	they get instead of a machine check on x86. */
	69	switch (len) {
	70	case 1:
	71	put_user(-1, (unsigned char __user *)buf);
	72	break;
	73	case 2:
	74	put_user(-1, (unsigned short __user *)buf);
	75	break;
	76	case 4:
	77	put_user(-1, (unsigned int __user *)buf);
	78	break;
e4585da2 AC	79	}
e4585da2 AC	80	pci_dev_put(dev);
1da177e4 LT	81	return err;
	82	}
	83
c4ea37c2 HC	84	SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
c4ea37c2 HC	85	unsigned long, off, unsigned long, len, void __user *, buf)
1da177e4 LT	86	{
	87	struct pci_dev *dev;
	88	u8 byte;
	89	u16 word;
	90	u32 dword;
	91	int err = 0;
	92
	93	if (!capable(CAP_SYS_ADMIN))
	94	return -EPERM;
	95
39c94652	96	dev = pci_get_domain_bus_and_slot(0, bus, dfn);
1da177e4 LT	97	if (!dev)
	98	return -ENODEV;
	99
3c78bc61	100	switch (len) {
1da177e4 LT	101	case 1:
	102	err = get_user(byte, (u8 __user *)buf);
	103	if (err)
	104	break;
e04b0ea2	105	err = pci_user_write_config_byte(dev, off, byte);
1da177e4 LT	106	if (err != PCIBIOS_SUCCESSFUL)
	107	err = -EIO;
	108	break;
	109
	110	case 2:
	111	err = get_user(word, (u16 __user *)buf);
	112	if (err)
	113	break;
e04b0ea2	114	err = pci_user_write_config_word(dev, off, word);
1da177e4 LT	115	if (err != PCIBIOS_SUCCESSFUL)
	116	err = -EIO;
	117	break;
	118
	119	case 4:
	120	err = get_user(dword, (u32 __user *)buf);
	121	if (err)
	122	break;
e04b0ea2	123	err = pci_user_write_config_dword(dev, off, dword);
1da177e4 LT	124	if (err != PCIBIOS_SUCCESSFUL)
	125	err = -EIO;
	126	break;
	127
	128	default:
	129	err = -EINVAL;
	130	break;
e4585da2	131	}
e4585da2	132	pci_dev_put(dev);
1da177e4 LT	133	return err;
1da177e4 LT	134	}