linux-imx

// 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 <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;

    }

​

    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;