[GitHub/MotorolaMobilityLLC/kernel-slsi.git] / drivers / pci / syscall.c

// SPDX-License-Identifier: GPL-2.0
/*
 *	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 <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_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;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* pci_syscall.c
	4	*
	5	* For architectures where we want to allow direct access
	6	* to the PCI config stuff - it would probably be preferable
	7	* on PCs too, but there people just do it by hand with the
	8	* magic northbridge registers..
	9	*/
	10
1da177e4 LT	11	#include <linux/errno.h>
1da177e4 LT	12	#include <linux/pci.h>
1da177e4	13	#include <linux/syscalls.h>
7c0f6ba6	14	#include <linux/uaccess.h>
e04b0ea2	15	#include "pci.h"
1da177e4	16
c4ea37c2 HC	17	SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
c4ea37c2 HC	18	unsigned long, off, unsigned long, len, void __user *, buf)
1da177e4 LT	19	{
	20	struct pci_dev *dev;
	21	u8 byte;
	22	u16 word;
	23	u32 dword;
e4585da2 AC	24	long err;
e4585da2 AC	25	long cfg_ret;
1da177e4	26
1da177e4	27	if (!capable(CAP_SYS_ADMIN))
e4585da2	28	return -EPERM;
1da177e4 LT	29
1da177e4 LT	30	err = -ENODEV;
e4585da2	31	dev = pci_get_bus_and_slot(bus, dfn);
1da177e4 LT	32	if (!dev)
	33	goto error;
	34
1da177e4 LT	35	switch (len) {
1da177e4 LT	36	case 1:
e04b0ea2	37	cfg_ret = pci_user_read_config_byte(dev, off, &byte);
1da177e4 LT	38	break;
1da177e4 LT	39	case 2:
e04b0ea2	40	cfg_ret = pci_user_read_config_word(dev, off, &word);
1da177e4 LT	41	break;
1da177e4 LT	42	case 4:
e04b0ea2	43	cfg_ret = pci_user_read_config_dword(dev, off, &dword);
1da177e4 LT	44	break;
	45	default:
	46	err = -EINVAL;
1da177e4	47	goto error;
f7625980	48	}
1da177e4 LT	49
	50	err = -EIO;
	51	if (cfg_ret != PCIBIOS_SUCCESSFUL)
	52	goto error;
	53
	54	switch (len) {
	55	case 1:
	56	err = put_user(byte, (unsigned char __user *)buf);
	57	break;
	58	case 2:
	59	err = put_user(word, (unsigned short __user *)buf);
	60	break;
	61	case 4:
	62	err = put_user(dword, (unsigned int __user *)buf);
	63	break;
e4585da2 AC	64	}
e4585da2 AC	65	pci_dev_put(dev);
1da177e4 LT	66	return err;
	67
	68	error:
	69	/* ??? XFree86 doesn't even check the return value. They
	70	just look for 0xffffffff in the output, since that's what
	71	they get instead of a machine check on x86. */
	72	switch (len) {
	73	case 1:
	74	put_user(-1, (unsigned char __user *)buf);
	75	break;
	76	case 2:
	77	put_user(-1, (unsigned short __user *)buf);
	78	break;
	79	case 4:
	80	put_user(-1, (unsigned int __user *)buf);
	81	break;
e4585da2 AC	82	}
e4585da2 AC	83	pci_dev_put(dev);
1da177e4 LT	84	return err;
	85	}
	86
c4ea37c2 HC	87	SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
c4ea37c2 HC	88	unsigned long, off, unsigned long, len, void __user *, buf)
1da177e4 LT	89	{
	90	struct pci_dev *dev;
	91	u8 byte;
	92	u16 word;
	93	u32 dword;
	94	int err = 0;
	95
	96	if (!capable(CAP_SYS_ADMIN))
	97	return -EPERM;
	98
e4585da2	99	dev = pci_get_bus_and_slot(bus, dfn);
1da177e4 LT	100	if (!dev)
	101	return -ENODEV;
	102
3c78bc61	103	switch (len) {
1da177e4 LT	104	case 1:
	105	err = get_user(byte, (u8 __user *)buf);
	106	if (err)
	107	break;
e04b0ea2	108	err = pci_user_write_config_byte(dev, off, byte);
1da177e4 LT	109	if (err != PCIBIOS_SUCCESSFUL)
	110	err = -EIO;
	111	break;
	112
	113	case 2:
	114	err = get_user(word, (u16 __user *)buf);
	115	if (err)
	116	break;
e04b0ea2	117	err = pci_user_write_config_word(dev, off, word);
1da177e4 LT	118	if (err != PCIBIOS_SUCCESSFUL)
	119	err = -EIO;
	120	break;
	121
	122	case 4:
	123	err = get_user(dword, (u32 __user *)buf);
	124	if (err)
	125	break;
e04b0ea2	126	err = pci_user_write_config_dword(dev, off, dword);
1da177e4 LT	127	if (err != PCIBIOS_SUCCESSFUL)
	128	err = -EIO;
	129	break;
	130
	131	default:
	132	err = -EINVAL;
	133	break;
e4585da2	134	}
e4585da2	135	pci_dev_put(dev);
1da177e4 LT	136	return err;
1da177e4 LT	137	}