drivers/pci/proc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Procfs interface for the PCI bus
  *
  * Copyright (c) 1997--1999 Martin Mares <mj@ucw.cz>
  */

 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/capability.h>
 #include <linux/uaccess.h>
 #include <linux/security.h>
 #include <asm/byteorder.h>
 #include "pci.h"

 static int proc_initialized;	/* = 0 */

 static loff_t proc_bus_pci_lseek(struct file *file, loff_t off, int whence)
 {
 	struct pci_dev *dev = pde_data(file_inode(file));
 	return fixed_size_llseek(file, off, whence, dev->cfg_size);
 }

 static ssize_t proc_bus_pci_read(struct file *file, char __user *buf,
 				 size_t nbytes, loff_t *ppos)
 {
 	struct pci_dev *dev = pde_data(file_inode(file));
 	unsigned int pos = *ppos;
 	unsigned int cnt, size;

 	/*
 	 * Normal users can read only the standardized portion of the
 	 * configuration space as several chips lock up when trying to read
 	 * undefined locations (think of Intel PIIX4 as a typical example).
 	 */

 	if (capable(CAP_SYS_ADMIN))
 		size = dev->cfg_size;
 	else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
 		size = 128;
 	else
 		size = 64;

 	if (pos >= size)
 		return 0;
 	if (nbytes >= size)
 		nbytes = size;
 	if (pos + nbytes > size)
 		nbytes = size - pos;
 	cnt = nbytes;

 	if (!access_ok(buf, cnt))
 		return -EINVAL;

 	pci_config_pm_runtime_get(dev);

 	if ((pos & 1) && cnt) {
 		unsigned char val;
 		pci_user_read_config_byte(dev, pos, &val);
 		__put_user(val, buf);
 		buf++;
 		pos++;
 		cnt--;
 	}

 	if ((pos & 3) && cnt > 2) {
 		unsigned short val;
 		pci_user_read_config_word(dev, pos, &val);
 		__put_user(cpu_to_le16(val), (__le16 __user *) buf);
 		buf += 2;
 		pos += 2;
 		cnt -= 2;
 	}

 	while (cnt >= 4) {
 		unsigned int val;
 		pci_user_read_config_dword(dev, pos, &val);
 		__put_user(cpu_to_le32(val), (__le32 __user *) buf);
 		buf += 4;
 		pos += 4;
 		cnt -= 4;
 		cond_resched();
 	}

 	if (cnt >= 2) {
 		unsigned short val;
 		pci_user_read_config_word(dev, pos, &val);
 		__put_user(cpu_to_le16(val), (__le16 __user *) buf);
 		buf += 2;
 		pos += 2;
 		cnt -= 2;
 	}

 	if (cnt) {
 		unsigned char val;
 		pci_user_read_config_byte(dev, pos, &val);
 		__put_user(val, buf);
 		pos++;
 	}

 	pci_config_pm_runtime_put(dev);

 	*ppos = pos;
 	return nbytes;
 }

 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, ret;

 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
 	if (ret)
 		return ret;

 	if (pos >= size)
 		return 0;
 	if (nbytes >= size)
 		nbytes = size;
 	if (pos + nbytes > size)
 		nbytes = size - pos;
 	cnt = nbytes;

 	if (!access_ok(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);
 		pos++;
 	}

 	pci_config_pm_runtime_put(dev);

 	*ppos = pos;
 	i_size_write(ino, dev->cfg_size);
 	return nbytes;
 }

 #ifdef HAVE_PCI_MMAP
 struct pci_filp_private {
 	enum pci_mmap_state mmap_state;
 	int write_combine;
 };
 #endif /* HAVE_PCI_MMAP */

 static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
 			       unsigned long arg)
 {
 	struct pci_dev *dev = pde_data(file_inode(file));
 #ifdef HAVE_PCI_MMAP
 	struct pci_filp_private *fpriv = file->private_data;
 #endif /* HAVE_PCI_MMAP */
 	int ret = 0;

 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
 	if (ret)
 		return ret;

 	switch (cmd) {
 	case PCIIOC_CONTROLLER:
 		ret = pci_domain_nr(dev->bus);
 		break;

 #ifdef HAVE_PCI_MMAP
 	case PCIIOC_MMAP_IS_IO:
 		if (!arch_can_pci_mmap_io())
 			return -EINVAL;
 		fpriv->mmap_state = pci_mmap_io;
 		break;

 	case PCIIOC_MMAP_IS_MEM:
 		fpriv->mmap_state = pci_mmap_mem;
 		break;

 	case PCIIOC_WRITE_COMBINE:
 		if (arch_can_pci_mmap_wc()) {
 			if (arg)
 				fpriv->write_combine = 1;
 			else
 				fpriv->write_combine = 0;
 			break;
 		}
 		/* If arch decided it can't, fall through... */
 		fallthrough;
 #endif /* HAVE_PCI_MMAP */
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 #ifdef HAVE_PCI_MMAP
 static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct pci_dev *dev = pde_data(file_inode(file));
 	struct pci_filp_private *fpriv = file->private_data;
 	resource_size_t start, end;
 	int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM;

 	if (!capable(CAP_SYS_RAWIO) ||
 	    security_locked_down(LOCKDOWN_PCI_ACCESS))
 		return -EPERM;

 	if (fpriv->mmap_state == pci_mmap_io) {
 		if (!arch_can_pci_mmap_io())
 			return -EINVAL;
 		res_bit = IORESOURCE_IO;
 	}

 	/* Make sure the caller is mapping a real resource for this device */
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (dev->resource[i].flags & res_bit &&
 		    pci_mmap_fits(dev, i, vma,  PCI_MMAP_PROCFS))
 			break;
 	}

 	if (i >= PCI_STD_NUM_BARS)
 		return -ENODEV;

 	if (fpriv->mmap_state == pci_mmap_mem &&
 	    fpriv->write_combine) {
 		if (dev->resource[i].flags & IORESOURCE_PREFETCH)
 			write_combine = 1;
 		else
 			return -EINVAL;
 	}

 	if (dev->resource[i].flags & IORESOURCE_MEM &&
 	    iomem_is_exclusive(dev->resource[i].start))
 		return -EINVAL;

 	pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);

 	/* Adjust vm_pgoff to be the offset within the resource */
 	vma->vm_pgoff -= start >> PAGE_SHIFT;
 	ret = pci_mmap_resource_range(dev, i, vma,
 				  fpriv->mmap_state, write_combine);
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int proc_bus_pci_open(struct inode *inode, struct file *file)
 {
 	struct pci_filp_private *fpriv = kmalloc(sizeof(*fpriv), GFP_KERNEL);

 	if (!fpriv)
 		return -ENOMEM;

 	fpriv->mmap_state = pci_mmap_io;
 	fpriv->write_combine = 0;

 	file->private_data = fpriv;
 	file->f_mapping = iomem_get_mapping();

 	return 0;
 }

 static int proc_bus_pci_release(struct inode *inode, struct file *file)
 {
 	kfree(file->private_data);
 	file->private_data = NULL;

 	return 0;
 }
 #endif /* HAVE_PCI_MMAP */

 static const struct proc_ops proc_bus_pci_ops = {
 	.proc_lseek	= proc_bus_pci_lseek,
 	.proc_read	= proc_bus_pci_read,
 	.proc_write	= proc_bus_pci_write,
 	.proc_ioctl	= proc_bus_pci_ioctl,
 #ifdef CONFIG_COMPAT
 	.proc_compat_ioctl = proc_bus_pci_ioctl,
 #endif
 #ifdef HAVE_PCI_MMAP
 	.proc_open	= proc_bus_pci_open,
 	.proc_release	= proc_bus_pci_release,
 	.proc_mmap	= proc_bus_pci_mmap,
 #ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA
 	.proc_get_unmapped_area = get_pci_unmapped_area,
 #endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */
 #endif /* HAVE_PCI_MMAP */
 };

 /* iterator */
 static void *pci_seq_start(struct seq_file *m, loff_t *pos)
 {
 	struct pci_dev *dev = NULL;
 	loff_t n = *pos;

 	for_each_pci_dev(dev) {
 		if (!n--)
 			break;
 	}
 	return dev;
 }

 static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	struct pci_dev *dev = v;

 	(*pos)++;
 	dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
 	return dev;
 }

 static void pci_seq_stop(struct seq_file *m, void *v)
 {
 	if (v) {
 		struct pci_dev *dev = v;
 		pci_dev_put(dev);
 	}
 }

 static int show_device(struct seq_file *m, void *v)
 {
 	const struct pci_dev *dev = v;
 	const struct pci_driver *drv;
 	int i;

 	if (dev == NULL)
 		return 0;

 	drv = pci_dev_driver(dev);
 	seq_printf(m, "%02x%02x\t%04x%04x\t%x",
 			dev->bus->number,
 			dev->devfn,
 			dev->vendor,
 			dev->device,
 			dev->irq);

 	/* only print standard and ROM resources to preserve compatibility */
 	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
 		resource_size_t start, end;
 		pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
 		seq_printf(m, "\t%16llx",
 			(unsigned long long)(start |
 			(dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
 	}
 	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
 		resource_size_t start, end;
 		pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
 		seq_printf(m, "\t%16llx",
 			dev->resource[i].start < dev->resource[i].end ?
 			(unsigned long long)(end - start) + 1 : 0);
 	}
 	seq_putc(m, '\t');
 	if (drv)
 		seq_puts(m, drv->name);
 	seq_putc(m, '\n');
 	return 0;
 }

 static const struct seq_operations proc_bus_pci_devices_op = {
 	.start	= pci_seq_start,
 	.next	= pci_seq_next,
 	.stop	= pci_seq_stop,
 	.show	= show_device
 };

 static struct proc_dir_entry *proc_bus_pci_dir;

 int pci_proc_attach_device(struct pci_dev *dev)
 {
 	struct pci_bus *bus = dev->bus;
 	struct proc_dir_entry *e;
 	char name[16];

 	if (!proc_initialized)
 		return -EACCES;

 	if (!bus->procdir) {
 		if (pci_proc_domain(bus)) {
 			sprintf(name, "%04x:%02x", pci_domain_nr(bus),
 					bus->number);
 		} else {
 			sprintf(name, "%02x", bus->number);
 		}
 		bus->procdir = proc_mkdir(name, proc_bus_pci_dir);
 		if (!bus->procdir)
 			return -ENOMEM;
 	}

 	sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
 	e = proc_create_data(name, S_IFREG | S_IRUGO | S_IWUSR, bus->procdir,
 			     &proc_bus_pci_ops, dev);
 	if (!e)
 		return -ENOMEM;
 	proc_set_size(e, dev->cfg_size);
 	dev->procent = e;

 	return 0;
 }

 int pci_proc_detach_device(struct pci_dev *dev)
 {
 	proc_remove(dev->procent);
 	dev->procent = NULL;
 	return 0;
 }

 int pci_proc_detach_bus(struct pci_bus *bus)
 {
 	proc_remove(bus->procdir);
 	return 0;
 }

 static int __init pci_proc_init(void)
 {
 	struct pci_dev *dev = NULL;
 	proc_bus_pci_dir = proc_mkdir("bus/pci", NULL);
 	proc_create_seq("devices", 0, proc_bus_pci_dir,
 		    &proc_bus_pci_devices_op);
 	proc_initialized = 1;
 	for_each_pci_dev(dev)
 		pci_proc_attach_device(dev);

 	return 0;
 }
 device_initcall(pci_proc_init);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Procfs interface for the PCI bus
	*
	* Copyright (c) 1997--1999 Martin Mares <mj@ucw.cz>
	*/

	#include <linux/init.h>
	#include <linux/pci.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/proc_fs.h>
	#include <linux/seq_file.h>
	#include <linux/capability.h>
	#include <linux/uaccess.h>
	#include <linux/security.h>
	#include <asm/byteorder.h>
	#include "pci.h"

	static int proc_initialized; /* = 0 */

	static loff_t proc_bus_pci_lseek(struct file *file, loff_t off, int whence)
	{
	struct pci_dev *dev = pde_data(file_inode(file));
	return fixed_size_llseek(file, off, whence, dev->cfg_size);
	}

	static ssize_t proc_bus_pci_read(struct file file, char __user buf,
	size_t nbytes, loff_t *ppos)
	{
	struct pci_dev *dev = pde_data(file_inode(file));
	unsigned int pos = *ppos;
	unsigned int cnt, size;

	/*
	* Normal users can read only the standardized portion of the
	* configuration space as several chips lock up when trying to read
	* undefined locations (think of Intel PIIX4 as a typical example).
	*/

	if (capable(CAP_SYS_ADMIN))
	size = dev->cfg_size;
	else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
	size = 128;
	else
	size = 64;

	if (pos >= size)
	return 0;
	if (nbytes >= size)
	nbytes = size;
	if (pos + nbytes > size)
	nbytes = size - pos;
	cnt = nbytes;

	if (!access_ok(buf, cnt))
	return -EINVAL;

	pci_config_pm_runtime_get(dev);

	if ((pos & 1) && cnt) {
	unsigned char val;
	pci_user_read_config_byte(dev, pos, &val);
	__put_user(val, buf);
	buf++;
	pos++;
	cnt--;
	}

	if ((pos & 3) && cnt > 2) {
	unsigned short val;
	pci_user_read_config_word(dev, pos, &val);
	__put_user(cpu_to_le16(val), (__le16 __user *) buf);
	buf += 2;
	pos += 2;
	cnt -= 2;
	}

	while (cnt >= 4) {
	unsigned int val;
	pci_user_read_config_dword(dev, pos, &val);
	__put_user(cpu_to_le32(val), (__le32 __user *) buf);
	buf += 4;
	pos += 4;
	cnt -= 4;
	cond_resched();
	}

	if (cnt >= 2) {
	unsigned short val;
	pci_user_read_config_word(dev, pos, &val);
	__put_user(cpu_to_le16(val), (__le16 __user *) buf);
	buf += 2;
	pos += 2;
	cnt -= 2;
	}

	if (cnt) {
	unsigned char val;
	pci_user_read_config_byte(dev, pos, &val);
	__put_user(val, buf);
	pos++;
	}

	pci_config_pm_runtime_put(dev);

	*ppos = pos;
	return nbytes;
	}

	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, ret;

	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
	if (ret)
	return ret;

	if (pos >= size)
	return 0;
	if (nbytes >= size)
	nbytes = size;
	if (pos + nbytes > size)
	nbytes = size - pos;
	cnt = nbytes;

	if (!access_ok(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);
	pos++;
	}

	pci_config_pm_runtime_put(dev);

	*ppos = pos;
	i_size_write(ino, dev->cfg_size);
	return nbytes;
	}

	#ifdef HAVE_PCI_MMAP
	struct pci_filp_private {
	enum pci_mmap_state mmap_state;
	int write_combine;
	};
	#endif /* HAVE_PCI_MMAP */

	static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	struct pci_dev *dev = pde_data(file_inode(file));
	#ifdef HAVE_PCI_MMAP
	struct pci_filp_private *fpriv = file->private_data;
	#endif /* HAVE_PCI_MMAP */
	int ret = 0;

	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
	if (ret)
	return ret;

	switch (cmd) {
	case PCIIOC_CONTROLLER:
	ret = pci_domain_nr(dev->bus);
	break;

	#ifdef HAVE_PCI_MMAP
	case PCIIOC_MMAP_IS_IO:
	if (!arch_can_pci_mmap_io())
	return -EINVAL;
	fpriv->mmap_state = pci_mmap_io;
	break;

	case PCIIOC_MMAP_IS_MEM:
	fpriv->mmap_state = pci_mmap_mem;
	break;

	case PCIIOC_WRITE_COMBINE:
	if (arch_can_pci_mmap_wc()) {
	if (arg)
	fpriv->write_combine = 1;
	else
	fpriv->write_combine = 0;
	break;
	}
	/* If arch decided it can't, fall through... */
	fallthrough;
	#endif /* HAVE_PCI_MMAP */
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	#ifdef HAVE_PCI_MMAP
	static int proc_bus_pci_mmap(struct file file, struct vm_area_struct vma)
	{
	struct pci_dev *dev = pde_data(file_inode(file));
	struct pci_filp_private *fpriv = file->private_data;
	resource_size_t start, end;
	int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM;

	if (!capable(CAP_SYS_RAWIO) \|\|
	security_locked_down(LOCKDOWN_PCI_ACCESS))
	return -EPERM;

	if (fpriv->mmap_state == pci_mmap_io) {
	if (!arch_can_pci_mmap_io())
	return -EINVAL;
	res_bit = IORESOURCE_IO;
	}

	/* Make sure the caller is mapping a real resource for this device */
	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
	if (dev->resource[i].flags & res_bit &&
	pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS))
	break;
	}

	if (i >= PCI_STD_NUM_BARS)
	return -ENODEV;

	if (fpriv->mmap_state == pci_mmap_mem &&
	fpriv->write_combine) {
	if (dev->resource[i].flags & IORESOURCE_PREFETCH)
	write_combine = 1;
	else
	return -EINVAL;
	}

	if (dev->resource[i].flags & IORESOURCE_MEM &&
	iomem_is_exclusive(dev->resource[i].start))
	return -EINVAL;

	pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);

	/* Adjust vm_pgoff to be the offset within the resource */
	vma->vm_pgoff -= start >> PAGE_SHIFT;
	ret = pci_mmap_resource_range(dev, i, vma,
	fpriv->mmap_state, write_combine);
	if (ret < 0)
	return ret;

	return 0;
	}

	static int proc_bus_pci_open(struct inode inode, struct file file)
	{
	struct pci_filp_private fpriv = kmalloc(sizeof(fpriv), GFP_KERNEL);

	if (!fpriv)
	return -ENOMEM;

	fpriv->mmap_state = pci_mmap_io;
	fpriv->write_combine = 0;

	file->private_data = fpriv;
	file->f_mapping = iomem_get_mapping();

	return 0;
	}

	static int proc_bus_pci_release(struct inode inode, struct file file)
	{
	kfree(file->private_data);
	file->private_data = NULL;

	return 0;
	}
	#endif /* HAVE_PCI_MMAP */

	static const struct proc_ops proc_bus_pci_ops = {
	.proc_lseek = proc_bus_pci_lseek,
	.proc_read = proc_bus_pci_read,
	.proc_write = proc_bus_pci_write,
	.proc_ioctl = proc_bus_pci_ioctl,
	#ifdef CONFIG_COMPAT
	.proc_compat_ioctl = proc_bus_pci_ioctl,
	#endif
	#ifdef HAVE_PCI_MMAP
	.proc_open = proc_bus_pci_open,
	.proc_release = proc_bus_pci_release,
	.proc_mmap = proc_bus_pci_mmap,
	#ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA
	.proc_get_unmapped_area = get_pci_unmapped_area,
	#endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */
	#endif /* HAVE_PCI_MMAP */
	};

	/* iterator */
	static void pci_seq_start(struct seq_file m, loff_t *pos)
	{
	struct pci_dev *dev = NULL;
	loff_t n = *pos;

	for_each_pci_dev(dev) {
	if (!n--)
	break;
	}
	return dev;
	}

	static void pci_seq_next(struct seq_file m, void v, loff_t pos)
	{
	struct pci_dev *dev = v;

	(*pos)++;
	dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
	return dev;
	}

	static void pci_seq_stop(struct seq_file m, void v)
	{
	if (v) {
	struct pci_dev *dev = v;
	pci_dev_put(dev);
	}
	}

	static int show_device(struct seq_file m, void v)
	{
	const struct pci_dev *dev = v;
	const struct pci_driver *drv;
	int i;

	if (dev == NULL)
	return 0;

	drv = pci_dev_driver(dev);
	seq_printf(m, "%02x%02x\t%04x%04x\t%x",
	dev->bus->number,
	dev->devfn,
	dev->vendor,
	dev->device,
	dev->irq);

	/* only print standard and ROM resources to preserve compatibility */
	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
	resource_size_t start, end;
	pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
	seq_printf(m, "\t%16llx",
	(unsigned long long)(start \|
	(dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
	}
	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
	resource_size_t start, end;
	pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
	seq_printf(m, "\t%16llx",
	dev->resource[i].start < dev->resource[i].end ?
	(unsigned long long)(end - start) + 1 : 0);
	}
	seq_putc(m, '\t');
	if (drv)
	seq_puts(m, drv->name);
	seq_putc(m, '\n');
	return 0;
	}

	static const struct seq_operations proc_bus_pci_devices_op = {
	.start = pci_seq_start,
	.next = pci_seq_next,
	.stop = pci_seq_stop,
	.show = show_device
	};

	static struct proc_dir_entry *proc_bus_pci_dir;

	int pci_proc_attach_device(struct pci_dev *dev)
	{
	struct pci_bus *bus = dev->bus;
	struct proc_dir_entry *e;
	char name[16];

	if (!proc_initialized)
	return -EACCES;

	if (!bus->procdir) {
	if (pci_proc_domain(bus)) {
	sprintf(name, "%04x:%02x", pci_domain_nr(bus),
	bus->number);
	} else {
	sprintf(name, "%02x", bus->number);
	}
	bus->procdir = proc_mkdir(name, proc_bus_pci_dir);
	if (!bus->procdir)
	return -ENOMEM;
	}

	sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
	e = proc_create_data(name, S_IFREG \| S_IRUGO \| S_IWUSR, bus->procdir,
	&proc_bus_pci_ops, dev);
	if (!e)
	return -ENOMEM;
	proc_set_size(e, dev->cfg_size);
	dev->procent = e;

	return 0;
	}

	int pci_proc_detach_device(struct pci_dev *dev)
	{
	proc_remove(dev->procent);
	dev->procent = NULL;
	return 0;
	}

	int pci_proc_detach_bus(struct pci_bus *bus)
	{
	proc_remove(bus->procdir);
	return 0;
	}

	static int __init pci_proc_init(void)
	{
	struct pci_dev *dev = NULL;
	proc_bus_pci_dir = proc_mkdir("bus/pci", NULL);
	proc_create_seq("devices", 0, proc_bus_pci_dir,
	&proc_bus_pci_devices_op);
	proc_initialized = 1;
	for_each_pci_dev(dev)
	pci_proc_attach_device(dev);

	return 0;
	}
	device_initcall(pci_proc_init);