/*
* Purpose: Export the firmware instance and label associated with
* a pci device to sysfs
* Copyright (C) 2010 Dell Inc.
* by Narendra K <Narendra_K@dell.com>,
* Jordan Hargrave <Jordan_Hargrave@dell.com>
*
* PCI Firmware Specification Revision 3.1 section 4.6.7 (DSM for Naming a
* PCI or PCI Express Device Under Operating Systems) defines an instance
* number and string name. This code retrieves them and exports them to sysfs.
* If the system firmware does not provide the ACPI _DSM (Device Specific
* Method), then the SMBIOS type 41 instance number and string is exported to
* sysfs.
*
* SMBIOS defines type 41 for onboard pci devices. This code retrieves
* the instance number and string from the type 41 record and exports
* it to sysfs.
*
* Please see http://linux.dell.com/wiki/index.php/Oss/libnetdevname for more
* information.
*/
#include <linux/dmi.h>
#include <linux/sysfs.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/nls.h>
#include <linux/acpi.h>
#include <linux/pci-acpi.h>
#include <acpi/acpi_bus.h>
#include "pci.h"
#define DEVICE_LABEL_DSM 0x07
#ifndef CONFIG_DMI
static inline int
pci_create_smbiosname_file(struct pci_dev *pdev)
{
return -1;
}
static inline void
pci_remove_smbiosname_file(struct pci_dev *pdev)
{
}
#else
enum smbios_attr_enum {
SMBIOS_ATTR_NONE = 0,
SMBIOS_ATTR_LABEL_SHOW,
SMBIOS_ATTR_INSTANCE_SHOW,
};
static size_t
find_smbios_instance_string(struct pci_dev *pdev, char *buf,
enum smbios_attr_enum attribute)
{
const struct dmi_device *dmi;
struct dmi_dev_onboard *donboard;
int bus;
int devfn;
bus = pdev->bus->number;
devfn = pdev->devfn;
dmi = NULL;
while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
NULL, dmi)) != NULL) {
donboard = dmi->device_data;
if (donboard && donboard->bus == bus &&
donboard->devfn == devfn) {
if (buf) {
if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
return scnprintf(buf, PAGE_SIZE,
"%d\n",
donboard->instance);
else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
return scnprintf(buf, PAGE_SIZE,
"%s\n",
dmi->name);
}
return strlen(dmi->name);
}
}
return 0;
}
static umode_t
smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
int n)
{
struct device *dev;
struct pci_dev *pdev;
dev = container_of(kobj, struct device, kobj);
pdev = to_pci_dev(dev);
return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
S_IRUGO : 0;
}
static ssize_t
smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pci_dev *pdev;
pdev = to_pci_dev(dev);
return find_smbios_instance_string(pdev, buf,
SMBIOS_ATTR_LABEL_SHOW);
}
static ssize_t
smbiosinstance_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pci_dev *pdev;
pdev = to_pci_dev(dev);
return find_smbios_instance_string(pdev, buf,
SMBIOS_ATTR_INSTANCE_SHOW);
}
static struct device_attribute smbios_attr_label = {
.attr = {.name = "label", .mode = 0444},
.show = smbioslabel_show,
};
static struct device_attribute smbios_attr_instance = {
.attr = {.name = "index", .mode = 0444},
.show = smbiosinstance_show,
};
static struct attribute *smbios_attributes[] = {
&smbios_attr_label.attr,
&smbios_attr_instance.attr,
NULL,
};
static struct attribute_group smbios_attr_group = {
.attrs = smbios_attributes,
.is_visible = smbios_instance_string_exist,
};
static int
pci_create_smbiosname_file(struct pci_dev *pdev)
{
return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
}
static void
pci_remove_smbiosname_file(struct pci_dev *pdev)
{
sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
}
#endif
#ifndef CONFIG_ACPI
static inline int
pci_create_acpi_index_label_files(struct pci_dev *pdev)
{
return -1;
}
static inline int
pci_remove_acpi_index_label_files(struct pci_dev *pdev)
{
return -1;
}
static inline bool
device_has_dsm(struct device *dev)
{
return false;
}
#else
static const char device_label_dsm_uuid[] = {
0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
};
enum acpi_attr_enum {
ACPI_ATTR_NONE = 0,
ACPI_ATTR_LABEL_SHOW,
ACPI_ATTR_INDEX_SHOW,
};
static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
{
int len;
len = utf16s_to_utf8s((const wchar_t *)obj->
package.elements[1].string.pointer,
obj->package.elements[1].string.length,
UTF16_LITTLE_ENDIAN,
buf, PAGE_SIZE);
buf[len] = '\n';
}
static int
dsm_get_label(acpi_handle handle, int func,
struct acpi_buffer *output,
char *buf, enum acpi_attr_enum attribute)
{
struct acpi_object_list input;
union acpi_object params[4];
union acpi_object *obj;
int len = 0;
int err;
input.count = 4;
input.pointer = params;
params[0].type = ACPI_TYPE_BUFFER;
params[0].buffer.length = sizeof(device_label_dsm_uuid);
params[0].buffer.pointer = (char *)device_label_dsm_uuid;
params[1].type = ACPI_TYPE_INTEGER;
params[1].integer.value = 0x02;
params[2].type = ACPI_TYPE_INTEGER;
params[2].integer.value = func;
params[3].type = ACPI_TYPE_PACKAGE;
params[3].package.count = 0;
params[3].package.elements = NULL;
err = acpi_evaluate_object(handle, "_DSM", &input, output);
if (err)
return -1;
obj = (union acpi_object *)output->pointer;
switch (obj->type) {
case ACPI_TYPE_PACKAGE:
if (obj->package.count != 2)
break;
len = obj->package.elements[0].integer.value;
if (buf) {
if (attribute == ACPI_ATTR_INDEX_SHOW)
scnprintf(buf, PAGE_SIZE, "%llu\n",
obj->package.elements[0].integer.value);
else if (attribute == ACPI_ATTR_LABEL_SHOW)
dsm_label_utf16s_to_utf8s(obj, buf);
kfree(output->pointer);
return strlen(buf);
}
kfree(output->pointer);
return len;
break;
default:
kfree(output->pointer);
}
return -1;
}
static bool
device_has_dsm(struct device *dev)
{
acpi_handle handle;
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
handle = DEVICE_ACPI_HANDLE(dev);
if (!handle)
return FALSE;
if (dsm_get_label(handle, DEVICE_LABEL_DSM, &output, NULL,
ACPI_ATTR_NONE) > 0)
return TRUE;
return FALSE;
}
static umode_t
acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
{
struct device *dev;
dev = container_of(kobj, struct device, kobj);
if (device_has_dsm(dev))
return S_IRUGO;
return 0;
}
static ssize_t
acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_handle handle;
int length;
handle = DEVICE_ACPI_HANDLE(dev);
if (!handle)
return -1;
length = dsm_get_label(handle, DEVICE_LABEL_DSM,
&output, buf, ACPI_ATTR_LABEL_SHOW);
if (length < 1)
return -1;
return length;
}
static ssize_t
acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_handle handle;
int length;
handle = DEVICE_ACPI_HANDLE(dev);
if (!handle)
return -1;
length = dsm_get_label(handle, DEVICE_LABEL_DSM,
&output, buf, ACPI_ATTR_INDEX_SHOW);
if (length < 0)
return -1;
return length;
}
static struct device_attribute acpi_attr_label = {
.attr = {.name = "label", .mode = 0444},
.show = acpilabel_show,
};
static struct device_attribute acpi_attr_index = {
.attr = {.name = "acpi_index", .mode = 0444},
.show = acpiindex_show,
};
static struct attribute *acpi_attributes[] = {
&acpi_attr_label.attr,
&acpi_attr_index.attr,
NULL,
};
static struct attribute_group acpi_attr_group = {
.attrs = acpi_attributes,
.is_visible = acpi_index_string_exist,
};
static int
pci_create_acpi_index_label_files(struct pci_dev *pdev)
{
return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
}
static int
pci_remove_acpi_index_label_files(struct pci_dev *pdev)
{
sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
return 0;
}
#endif
void pci_create_firmware_label_files(struct pci_dev *pdev)
{
if (device_has_dsm(&pdev->dev))
pci_create_acpi_index_label_files(pdev);
else
pci_create_smbiosname_file(pdev);
}
void pci_remove_firmware_label_files(struct pci_dev *pdev)
{
if (device_has_dsm(&pdev->dev))
pci_remove_acpi_index_label_files(pdev);
else
pci_remove_smbiosname_file(pdev);
}
