proc.c

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/*
 *  Procfs interface for the PCI bus.
 *
 *  Copyright (c) 1997--1999 Martin Mares <[email protected]>
 */

#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 <asm/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)
{
    loff_t new = -1;
    struct inode *inode = file->f_path.dentry->d_inode;

    mutex_lock(&inode->i_mutex);
    switch (whence) {
    case 0:
        new = off;
        break;
    case 1:
        new = file->f_pos + off;
        break;
    case 2:
        new = inode->i_size + off;
        break;
    }
    if (new < 0 || new > inode->i_size)
        new = -EINVAL;
    else
        file->f_pos = new;
    mutex_unlock(&inode->i_mutex);
    return new;
}

static ssize_t
proc_bus_pci_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
    const struct inode *ino = file->f_path.dentry->d_inode;
    const struct proc_dir_entry *dp = PDE(ino);
    struct pci_dev *dev = dp->data;
    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 = dp->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(VERIFY_WRITE, 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;
        cnt -= 2;
    }

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

    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->f_path.dentry->d_inode;
    const struct proc_dir_entry *dp = PDE(ino);
    struct pci_dev *dev = dp->data;
    int pos = *ppos;
    int size = dp->size;
    int cnt;

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

    if (!access_ok(VERIFY_READ, 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);
        buf++;
        pos++;
        cnt--;
    }

    pci_config_pm_runtime_put(dev);

    *ppos = pos;
    i_size_write(ino, dp->size);
    return nbytes;
}

struct pci_filp_private {
    enum pci_mmap_state mmap_state;
    int write_combine;
};

static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
                   unsigned long arg)
{
    const struct proc_dir_entry *dp = PDE(file->f_dentry->d_inode);
    struct pci_dev *dev = dp->data;
#ifdef HAVE_PCI_MMAP
    struct pci_filp_private *fpriv = file->private_data;
#endif /* HAVE_PCI_MMAP */
    int ret = 0;

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

#ifdef HAVE_PCI_MMAP
    case PCIIOC_MMAP_IS_IO:
        fpriv->mmap_state = pci_mmap_io;
        break;

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

    case PCIIOC_WRITE_COMBINE:
        if (arg)
            fpriv->write_combine = 1;
        else
            fpriv->write_combine = 0;
        break;

#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 inode *inode = file->f_path.dentry->d_inode;
    const struct proc_dir_entry *dp = PDE(inode);
    struct pci_dev *dev = dp->data;
    struct pci_filp_private *fpriv = file->private_data;
    int i, ret;

    if (!capable(CAP_SYS_RAWIO))
        return -EPERM;

    /* Make sure the caller is mapping a real resource for this device */
    for (i = 0; i < PCI_ROM_RESOURCE; i++) {
        if (pci_mmap_fits(dev, i, vma,  PCI_MMAP_PROCFS))
            break;
    }

    if (i >= PCI_ROM_RESOURCE)
        return -ENODEV;

    ret = pci_mmap_page_range(dev, vma,
                  fpriv->mmap_state,
                  fpriv->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;

    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 file_operations proc_bus_pci_operations = {
    .owner      = THIS_MODULE,
    .llseek     = proc_bus_pci_lseek,
    .read       = proc_bus_pci_read,
    .write      = proc_bus_pci_write,
    .unlocked_ioctl = proc_bus_pci_ioctl,
    .compat_ioctl   = proc_bus_pci_ioctl,
#ifdef HAVE_PCI_MMAP
    .open       = proc_bus_pci_open,
    .release    = proc_bus_pci_release,
    .mmap       = proc_bus_pci_mmap,
#ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA
    .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_printf(m, "%s", 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_operations, dev);
    if (!e)
        return -ENOMEM;
    e->size = dev->cfg_size;
    dev->procent = e;

    return 0;
}

int pci_proc_detach_device(struct pci_dev *dev)
{
    struct proc_dir_entry *e;

    if ((e = dev->procent)) {
        remove_proc_entry(e->name, dev->bus->procdir);
        dev->procent = NULL;
    }
    return 0;
}

int pci_proc_detach_bus(struct pci_bus* bus)
{
    struct proc_dir_entry *de = bus->procdir;
    if (de)
        remove_proc_entry(de->name, proc_bus_pci_dir);
    return 0;
}

static int proc_bus_pci_dev_open(struct inode *inode, struct file *file)
{
    return seq_open(file, &proc_bus_pci_devices_op);
}
static const struct file_operations proc_bus_pci_dev_operations = {
    .owner      = THIS_MODULE,
    .open       = proc_bus_pci_dev_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = seq_release,
};

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

    return 0;
}

device_initcall(pci_proc_init);