linux/drivers/pci/pci-sysfs.c
Arjan van de Ven 9f125d3048 [PATCH] PCI: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access
This patch adds an "enable" sysfs attribute to each PCI device. When read it
shows the "enabled-ness" of the device, but you can write a "0" into it to
disable a device, and a "1" to enable it.

This later is needed for X and other cases where userspace wants to enable
the BARs on a device (typical example: to run the video bios on a secundary
head). Right now X does all this "by hand" via bitbanging, that's just evil.
This allows X to no longer do that but to just let the kernel do this.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
CC: Peter Jones <pjones@redhat.com>
Acked-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-21 11:59:59 -07:00

577 lines
14 KiB
C

/*
* drivers/pci/pci-sysfs.c
*
* (C) Copyright 2002-2004 Greg Kroah-Hartman <greg@kroah.com>
* (C) Copyright 2002-2004 IBM Corp.
* (C) Copyright 2003 Matthew Wilcox
* (C) Copyright 2003 Hewlett-Packard
* (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
* (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
*
* File attributes for PCI devices
*
* Modeled after usb's driverfs.c
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/stat.h>
#include <linux/topology.h>
#include <linux/mm.h>
#include "pci.h"
static int sysfs_initialized; /* = 0 */
/* show configuration fields */
#define pci_config_attr(field, format_string) \
static ssize_t \
field##_show(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct pci_dev *pdev; \
\
pdev = to_pci_dev (dev); \
return sprintf (buf, format_string, pdev->field); \
}
pci_config_attr(vendor, "0x%04x\n");
pci_config_attr(device, "0x%04x\n");
pci_config_attr(subsystem_vendor, "0x%04x\n");
pci_config_attr(subsystem_device, "0x%04x\n");
pci_config_attr(class, "0x%06x\n");
pci_config_attr(irq, "%u\n");
pci_config_attr(is_enabled, "%u\n");
static ssize_t local_cpus_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
cpumask_t mask;
int len;
mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
strcat(buf,"\n");
return 1+len;
}
/* show resources */
static ssize_t
resource_show(struct device * dev, struct device_attribute *attr, char * buf)
{
struct pci_dev * pci_dev = to_pci_dev(dev);
char * str = buf;
int i;
int max = 7;
u64 start, end;
if (pci_dev->subordinate)
max = DEVICE_COUNT_RESOURCE;
for (i = 0; i < max; i++) {
struct resource *res = &pci_dev->resource[i];
pci_resource_to_user(pci_dev, i, res, &start, &end);
str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
(unsigned long long)start,
(unsigned long long)end,
(unsigned long long)res->flags);
}
return (str - buf);
}
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
pci_dev->vendor, pci_dev->device,
pci_dev->subsystem_vendor, pci_dev->subsystem_device,
(u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
(u8)(pci_dev->class));
}
static ssize_t
is_enabled_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct pci_dev *pdev = to_pci_dev(dev);
/* this can crash the machine when done on the "wrong" device */
if (!capable(CAP_SYS_ADMIN))
return count;
if (*buf == '0')
pci_disable_device(pdev);
if (*buf == '1')
pci_enable_device(pdev);
return count;
}
struct device_attribute pci_dev_attrs[] = {
__ATTR_RO(resource),
__ATTR_RO(vendor),
__ATTR_RO(device),
__ATTR_RO(subsystem_vendor),
__ATTR_RO(subsystem_device),
__ATTR_RO(class),
__ATTR_RO(irq),
__ATTR_RO(local_cpus),
__ATTR_RO(modalias),
__ATTR(enable, 0600, is_enabled_show, is_enabled_store),
__ATTR_NULL,
};
static ssize_t
pci_read_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
unsigned int size = 64;
loff_t init_off = off;
u8 *data = (u8*) buf;
/* Several chips lock up trying to read undefined config space */
if (capable(CAP_SYS_ADMIN)) {
size = dev->cfg_size;
} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
size = 128;
}
if (off > size)
return 0;
if (off + count > size) {
size -= off;
count = size;
} else {
size = count;
}
if ((off & 1) && size) {
u8 val;
pci_user_read_config_byte(dev, off, &val);
data[off - init_off] = val;
off++;
size--;
}
if ((off & 3) && size > 2) {
u16 val;
pci_user_read_config_word(dev, off, &val);
data[off - init_off] = val & 0xff;
data[off - init_off + 1] = (val >> 8) & 0xff;
off += 2;
size -= 2;
}
while (size > 3) {
u32 val;
pci_user_read_config_dword(dev, off, &val);
data[off - init_off] = val & 0xff;
data[off - init_off + 1] = (val >> 8) & 0xff;
data[off - init_off + 2] = (val >> 16) & 0xff;
data[off - init_off + 3] = (val >> 24) & 0xff;
off += 4;
size -= 4;
}
if (size >= 2) {
u16 val;
pci_user_read_config_word(dev, off, &val);
data[off - init_off] = val & 0xff;
data[off - init_off + 1] = (val >> 8) & 0xff;
off += 2;
size -= 2;
}
if (size > 0) {
u8 val;
pci_user_read_config_byte(dev, off, &val);
data[off - init_off] = val;
off++;
--size;
}
return count;
}
static ssize_t
pci_write_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
unsigned int size = count;
loff_t init_off = off;
u8 *data = (u8*) buf;
if (off > dev->cfg_size)
return 0;
if (off + count > dev->cfg_size) {
size = dev->cfg_size - off;
count = size;
}
if ((off & 1) && size) {
pci_user_write_config_byte(dev, off, data[off - init_off]);
off++;
size--;
}
if ((off & 3) && size > 2) {
u16 val = data[off - init_off];
val |= (u16) data[off - init_off + 1] << 8;
pci_user_write_config_word(dev, off, val);
off += 2;
size -= 2;
}
while (size > 3) {
u32 val = data[off - init_off];
val |= (u32) data[off - init_off + 1] << 8;
val |= (u32) data[off - init_off + 2] << 16;
val |= (u32) data[off - init_off + 3] << 24;
pci_user_write_config_dword(dev, off, val);
off += 4;
size -= 4;
}
if (size >= 2) {
u16 val = data[off - init_off];
val |= (u16) data[off - init_off + 1] << 8;
pci_user_write_config_word(dev, off, val);
off += 2;
size -= 2;
}
if (size) {
pci_user_write_config_byte(dev, off, data[off - init_off]);
off++;
--size;
}
return count;
}
#ifdef HAVE_PCI_LEGACY
/**
* pci_read_legacy_io - read byte(s) from legacy I/O port space
* @kobj: kobject corresponding to file to read from
* @buf: buffer to store results
* @off: offset into legacy I/O port space
* @count: number of bytes to read
*
* Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
* callback routine (pci_legacy_read).
*/
ssize_t
pci_read_legacy_io(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct pci_bus *bus = to_pci_bus(container_of(kobj,
struct class_device,
kobj));
/* Only support 1, 2 or 4 byte accesses */
if (count != 1 && count != 2 && count != 4)
return -EINVAL;
return pci_legacy_read(bus, off, (u32 *)buf, count);
}
/**
* pci_write_legacy_io - write byte(s) to legacy I/O port space
* @kobj: kobject corresponding to file to read from
* @buf: buffer containing value to be written
* @off: offset into legacy I/O port space
* @count: number of bytes to write
*
* Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
* callback routine (pci_legacy_write).
*/
ssize_t
pci_write_legacy_io(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct pci_bus *bus = to_pci_bus(container_of(kobj,
struct class_device,
kobj));
/* Only support 1, 2 or 4 byte accesses */
if (count != 1 && count != 2 && count != 4)
return -EINVAL;
return pci_legacy_write(bus, off, *(u32 *)buf, count);
}
/**
* pci_mmap_legacy_mem - map legacy PCI memory into user memory space
* @kobj: kobject corresponding to device to be mapped
* @attr: struct bin_attribute for this file
* @vma: struct vm_area_struct passed to mmap
*
* Uses an arch specific callback, pci_mmap_legacy_page_range, to mmap
* legacy memory space (first meg of bus space) into application virtual
* memory space.
*/
int
pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
struct vm_area_struct *vma)
{
struct pci_bus *bus = to_pci_bus(container_of(kobj,
struct class_device,
kobj));
return pci_mmap_legacy_page_range(bus, vma);
}
#endif /* HAVE_PCI_LEGACY */
#ifdef HAVE_PCI_MMAP
/**
* pci_mmap_resource - map a PCI resource into user memory space
* @kobj: kobject for mapping
* @attr: struct bin_attribute for the file being mapped
* @vma: struct vm_area_struct passed into the mmap
*
* Use the regular PCI mapping routines to map a PCI resource into userspace.
* FIXME: write combining? maybe automatic for prefetchable regions?
*/
static int
pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
struct vm_area_struct *vma)
{
struct pci_dev *pdev = to_pci_dev(container_of(kobj,
struct device, kobj));
struct resource *res = (struct resource *)attr->private;
enum pci_mmap_state mmap_type;
u64 start, end;
int i;
for (i = 0; i < PCI_ROM_RESOURCE; i++)
if (res == &pdev->resource[i])
break;
if (i >= PCI_ROM_RESOURCE)
return -ENODEV;
/* pci_mmap_page_range() expects the same kind of entry as coming
* from /proc/bus/pci/ which is a "user visible" value. If this is
* different from the resource itself, arch will do necessary fixup.
*/
pci_resource_to_user(pdev, i, res, &start, &end);
vma->vm_pgoff += start >> PAGE_SHIFT;
mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
return pci_mmap_page_range(pdev, vma, mmap_type, 0);
}
/**
* pci_create_resource_files - create resource files in sysfs for @dev
* @dev: dev in question
*
* Walk the resources in @dev creating files for each resource available.
*/
static void
pci_create_resource_files(struct pci_dev *pdev)
{
int i;
/* Expose the PCI resources from this device as files */
for (i = 0; i < PCI_ROM_RESOURCE; i++) {
struct bin_attribute *res_attr;
/* skip empty resources */
if (!pci_resource_len(pdev, i))
continue;
/* allocate attribute structure, piggyback attribute name */
res_attr = kzalloc(sizeof(*res_attr) + 10, GFP_ATOMIC);
if (res_attr) {
char *res_attr_name = (char *)(res_attr + 1);
pdev->res_attr[i] = res_attr;
sprintf(res_attr_name, "resource%d", i);
res_attr->attr.name = res_attr_name;
res_attr->attr.mode = S_IRUSR | S_IWUSR;
res_attr->attr.owner = THIS_MODULE;
res_attr->size = pci_resource_len(pdev, i);
res_attr->mmap = pci_mmap_resource;
res_attr->private = &pdev->resource[i];
sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
}
}
}
/**
* pci_remove_resource_files - cleanup resource files
* @dev: dev to cleanup
*
* If we created resource files for @dev, remove them from sysfs and
* free their resources.
*/
static void
pci_remove_resource_files(struct pci_dev *pdev)
{
int i;
for (i = 0; i < PCI_ROM_RESOURCE; i++) {
struct bin_attribute *res_attr;
res_attr = pdev->res_attr[i];
if (res_attr) {
sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
kfree(res_attr);
}
}
}
#else /* !HAVE_PCI_MMAP */
static inline void pci_create_resource_files(struct pci_dev *dev) { return; }
static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }
#endif /* HAVE_PCI_MMAP */
/**
* pci_write_rom - used to enable access to the PCI ROM display
* @kobj: kernel object handle
* @buf: user input
* @off: file offset
* @count: number of byte in input
*
* writing anything except 0 enables it
*/
static ssize_t
pci_write_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
if ((off == 0) && (*buf == '0') && (count == 2))
pdev->rom_attr_enabled = 0;
else
pdev->rom_attr_enabled = 1;
return count;
}
/**
* pci_read_rom - read a PCI ROM
* @kobj: kernel object handle
* @buf: where to put the data we read from the ROM
* @off: file offset
* @count: number of bytes to read
*
* Put @count bytes starting at @off into @buf from the ROM in the PCI
* device corresponding to @kobj.
*/
static ssize_t
pci_read_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
void __iomem *rom;
size_t size;
if (!pdev->rom_attr_enabled)
return -EINVAL;
rom = pci_map_rom(pdev, &size); /* size starts out as PCI window size */
if (!rom)
return 0;
if (off >= size)
count = 0;
else {
if (off + count > size)
count = size - off;
memcpy_fromio(buf, rom + off, count);
}
pci_unmap_rom(pdev, rom);
return count;
}
static struct bin_attribute pci_config_attr = {
.attr = {
.name = "config",
.mode = S_IRUGO | S_IWUSR,
.owner = THIS_MODULE,
},
.size = 256,
.read = pci_read_config,
.write = pci_write_config,
};
static struct bin_attribute pcie_config_attr = {
.attr = {
.name = "config",
.mode = S_IRUGO | S_IWUSR,
.owner = THIS_MODULE,
},
.size = 4096,
.read = pci_read_config,
.write = pci_write_config,
};
int pci_create_sysfs_dev_files (struct pci_dev *pdev)
{
if (!sysfs_initialized)
return -EACCES;
if (pdev->cfg_size < 4096)
sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
else
sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
pci_create_resource_files(pdev);
/* If the device has a ROM, try to expose it in sysfs. */
if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
struct bin_attribute *rom_attr;
rom_attr = kzalloc(sizeof(*rom_attr), GFP_ATOMIC);
if (rom_attr) {
pdev->rom_attr = rom_attr;
rom_attr->size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
rom_attr->attr.name = "rom";
rom_attr->attr.mode = S_IRUSR;
rom_attr->attr.owner = THIS_MODULE;
rom_attr->read = pci_read_rom;
rom_attr->write = pci_write_rom;
sysfs_create_bin_file(&pdev->dev.kobj, rom_attr);
}
}
/* add platform-specific attributes */
pcibios_add_platform_entries(pdev);
return 0;
}
/**
* pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
* @pdev: device whose entries we should free
*
* Cleanup when @pdev is removed from sysfs.
*/
void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
{
if (pdev->cfg_size < 4096)
sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
else
sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
pci_remove_resource_files(pdev);
if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
if (pdev->rom_attr) {
sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
kfree(pdev->rom_attr);
}
}
}
static int __init pci_sysfs_init(void)
{
struct pci_dev *pdev = NULL;
sysfs_initialized = 1;
for_each_pci_dev(pdev)
pci_create_sysfs_dev_files(pdev);
return 0;
}
__initcall(pci_sysfs_init);