linux/drivers/pci/proc.c
Huang Ying b3c32c4f95 PCI/PM: Fix proc config reg access for D3cold and bridge suspending
In https://bugzilla.kernel.org/show_bug.cgi?id=48981
Peter reported that /proc/bus/pci/??/??.? does not work for 3.6.
This is because the device configuration space registers are
not accessible if the corresponding parent bridge is suspended or
the device is put into D3cold state.

This is the same as /sys/bus/pci/devices/0000:??:??.?/config access
issue.  So the function used to solve sysfs issue is used to solve
this issue.

This patch moves pci_config_pm_runtime_get()/_put() from pci/pci-sysfs.c
to pci/pci.c and makes them extern so they can be used by both the
sysfs and proc paths.

[bhelgaas: changelog, references, reporters]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=48981
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=49031
Reported-by: Forrest Loomis <cybercyst@gmail.com>
Reported-by: Peter <lekensteyn@gmail.com>
Reported-by: Micael Dias <kam1kaz3@gmail.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: stable@vger.kernel.org		# v3.6+
2012-11-05 10:46:23 -07:00

480 lines
9.7 KiB
C

/*
* 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 <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);