linux/drivers/acpi/device_sysfs.c
Hans de Goede 10809bb976 ACPI / bus: Leave modalias empty for devices which are not present
Most Bay and Cherry Trail devices use a generic DSDT with all possible
peripheral devices present in the DSDT, with their _STA returning 0x00 or
0x0f based on AML variables which describe what is actually present on
the board.

Since ACPI device objects with a 0x00 status (not present) still get an
entry under /sys/bus/acpi/devices, and those entry had an acpi:PNPID
modalias, userspace would end up loading modules for non present hardware.

This commit fixes this by leaving the modalias empty for non present
devices. This results in 10 modules less being loaded with a generic
distro kernel config on my Cherry Trail test-device (a GPD pocket).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-20 23:48:51 +01:00

648 lines
17 KiB
C

/*
* drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
*
* Copyright (C) 2015, Intel Corp.
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/nls.h>
#include "internal.h"
static ssize_t acpi_object_path(acpi_handle handle, char *buf)
{
struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
int result;
result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
if (result)
return result;
result = sprintf(buf, "%s\n", (char *)path.pointer);
kfree(path.pointer);
return result;
}
struct acpi_data_node_attr {
struct attribute attr;
ssize_t (*show)(struct acpi_data_node *, char *);
ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
};
#define DATA_NODE_ATTR(_name) \
static struct acpi_data_node_attr data_node_##_name = \
__ATTR(_name, 0444, data_node_show_##_name, NULL)
static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
{
return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
}
DATA_NODE_ATTR(path);
static struct attribute *acpi_data_node_default_attrs[] = {
&data_node_path.attr,
NULL
};
#define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
#define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct acpi_data_node *dn = to_data_node(kobj);
struct acpi_data_node_attr *dn_attr = to_attr(attr);
return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
}
static const struct sysfs_ops acpi_data_node_sysfs_ops = {
.show = acpi_data_node_attr_show,
};
static void acpi_data_node_release(struct kobject *kobj)
{
struct acpi_data_node *dn = to_data_node(kobj);
complete(&dn->kobj_done);
}
static struct kobj_type acpi_data_node_ktype = {
.sysfs_ops = &acpi_data_node_sysfs_ops,
.default_attrs = acpi_data_node_default_attrs,
.release = acpi_data_node_release,
};
static void acpi_expose_nondev_subnodes(struct kobject *kobj,
struct acpi_device_data *data)
{
struct list_head *list = &data->subnodes;
struct acpi_data_node *dn;
if (list_empty(list))
return;
list_for_each_entry(dn, list, sibling) {
int ret;
init_completion(&dn->kobj_done);
ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
kobj, "%s", dn->name);
if (!ret)
acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
else if (dn->handle)
acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
}
}
static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
{
struct list_head *list = &data->subnodes;
struct acpi_data_node *dn;
if (list_empty(list))
return;
list_for_each_entry_reverse(dn, list, sibling) {
acpi_hide_nondev_subnodes(&dn->data);
kobject_put(&dn->kobj);
}
}
/**
* create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
* @acpi_dev: ACPI device object.
* @modalias: Buffer to print into.
* @size: Size of the buffer.
*
* Creates hid/cid(s) string needed for modalias and uevent
* e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
* char *modalias: "acpi:IBM0001:ACPI0001"
* Return: 0: no _HID and no _CID
* -EINVAL: output error
* -ENOMEM: output is truncated
*/
static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
int size)
{
int len;
int count;
struct acpi_hardware_id *id;
/* Avoid unnecessarily loading modules for non present devices. */
if (!acpi_device_is_present(acpi_dev))
return 0;
/*
* Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
* be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
* device's list.
*/
count = 0;
list_for_each_entry(id, &acpi_dev->pnp.ids, list)
if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
count++;
if (!count)
return 0;
len = snprintf(modalias, size, "acpi:");
if (len <= 0)
return len;
size -= len;
list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
continue;
count = snprintf(&modalias[len], size, "%s:", id->id);
if (count < 0)
return -EINVAL;
if (count >= size)
return -ENOMEM;
len += count;
size -= count;
}
modalias[len] = '\0';
return len;
}
/**
* create_of_modalias - Creates DT compatible string for modalias and uevent
* @acpi_dev: ACPI device object.
* @modalias: Buffer to print into.
* @size: Size of the buffer.
*
* Expose DT compatible modalias as of:NnameTCcompatible. This function should
* only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
* ACPI/PNP IDs.
*/
static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
int size)
{
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
const union acpi_object *of_compatible, *obj;
int len, count;
int i, nval;
char *c;
acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
/* DT strings are all in lower case */
for (c = buf.pointer; *c != '\0'; c++)
*c = tolower(*c);
len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
ACPI_FREE(buf.pointer);
if (len <= 0)
return len;
of_compatible = acpi_dev->data.of_compatible;
if (of_compatible->type == ACPI_TYPE_PACKAGE) {
nval = of_compatible->package.count;
obj = of_compatible->package.elements;
} else { /* Must be ACPI_TYPE_STRING. */
nval = 1;
obj = of_compatible;
}
for (i = 0; i < nval; i++, obj++) {
count = snprintf(&modalias[len], size, "C%s",
obj->string.pointer);
if (count < 0)
return -EINVAL;
if (count >= size)
return -ENOMEM;
len += count;
size -= count;
}
modalias[len] = '\0';
return len;
}
int __acpi_device_uevent_modalias(struct acpi_device *adev,
struct kobj_uevent_env *env)
{
int len;
if (!adev)
return -ENODEV;
if (list_empty(&adev->pnp.ids))
return 0;
if (add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
sizeof(env->buf) - env->buflen);
if (len < 0)
return len;
env->buflen += len;
if (!adev->data.of_compatible)
return 0;
if (len > 0 && add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
len = create_of_modalias(adev, &env->buf[env->buflen - 1],
sizeof(env->buf) - env->buflen);
if (len < 0)
return len;
env->buflen += len;
return 0;
}
/**
* acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
*
* Create the uevent modalias field for ACPI-enumerated devices.
*
* Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
* hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
*/
int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
{
return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
}
EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
{
int len, count;
if (!adev)
return -ENODEV;
if (list_empty(&adev->pnp.ids))
return 0;
len = create_pnp_modalias(adev, buf, size - 1);
if (len < 0) {
return len;
} else if (len > 0) {
buf[len++] = '\n';
size -= len;
}
if (!adev->data.of_compatible)
return len;
count = create_of_modalias(adev, buf + len, size - 1);
if (count < 0) {
return count;
} else if (count > 0) {
len += count;
buf[len++] = '\n';
}
return len;
}
/**
* acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
*
* Create the modalias sysfs attribute for ACPI-enumerated devices.
*
* Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
* hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
*/
int acpi_device_modalias(struct device *dev, char *buf, int size)
{
return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
}
EXPORT_SYMBOL_GPL(acpi_device_modalias);
static ssize_t
acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
}
static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
static ssize_t real_power_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *adev = to_acpi_device(dev);
int state;
int ret;
ret = acpi_device_get_power(adev, &state);
if (ret)
return ret;
return sprintf(buf, "%s\n", acpi_power_state_string(state));
}
static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
static ssize_t power_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *adev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
}
static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
static ssize_t
acpi_eject_store(struct device *d, struct device_attribute *attr,
const char *buf, size_t count)
{
struct acpi_device *acpi_device = to_acpi_device(d);
acpi_object_type not_used;
acpi_status status;
if (!count || buf[0] != '1')
return -EINVAL;
if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
&& !acpi_device->driver)
return -ENODEV;
status = acpi_get_type(acpi_device->handle, &not_used);
if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
return -ENODEV;
get_device(&acpi_device->dev);
status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
if (ACPI_SUCCESS(status))
return count;
put_device(&acpi_device->dev);
acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
}
static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
static ssize_t
acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
}
static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
static ssize_t acpi_device_uid_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
}
static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
static ssize_t acpi_device_adr_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "0x%08x\n",
(unsigned int)(acpi_dev->pnp.bus_address));
}
static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
static ssize_t acpi_device_path_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return acpi_object_path(acpi_dev->handle, buf);
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
/* sysfs file that shows description text from the ACPI _STR method */
static ssize_t description_show(struct device *dev,
struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
int result;
if (acpi_dev->pnp.str_obj == NULL)
return 0;
/*
* The _STR object contains a Unicode identifier for a device.
* We need to convert to utf-8 so it can be displayed.
*/
result = utf16s_to_utf8s(
(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
acpi_dev->pnp.str_obj->buffer.length,
UTF16_LITTLE_ENDIAN, buf,
PAGE_SIZE);
buf[result++] = '\n';
return result;
}
static DEVICE_ATTR(description, 0444, description_show, NULL);
static ssize_t
acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
acpi_status status;
unsigned long long sun;
status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
if (ACPI_FAILURE(status))
return -EIO;
return sprintf(buf, "%llu\n", sun);
}
static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
static ssize_t
acpi_device_hrv_show(struct device *dev, struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
acpi_status status;
unsigned long long hrv;
status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
if (ACPI_FAILURE(status))
return -EIO;
return sprintf(buf, "%llu\n", hrv);
}
static DEVICE_ATTR(hrv, 0444, acpi_device_hrv_show, NULL);
static ssize_t status_show(struct device *dev, struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
acpi_status status;
unsigned long long sta;
status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -EIO;
return sprintf(buf, "%llu\n", sta);
}
static DEVICE_ATTR_RO(status);
/**
* acpi_device_setup_files - Create sysfs attributes of an ACPI device.
* @dev: ACPI device object.
*/
int acpi_device_setup_files(struct acpi_device *dev)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
int result = 0;
/*
* Devices gotten from FADT don't have a "path" attribute
*/
if (dev->handle) {
result = device_create_file(&dev->dev, &dev_attr_path);
if (result)
goto end;
}
if (!list_empty(&dev->pnp.ids)) {
result = device_create_file(&dev->dev, &dev_attr_hid);
if (result)
goto end;
result = device_create_file(&dev->dev, &dev_attr_modalias);
if (result)
goto end;
}
/*
* If device has _STR, 'description' file is created
*/
if (acpi_has_method(dev->handle, "_STR")) {
status = acpi_evaluate_object(dev->handle, "_STR",
NULL, &buffer);
if (ACPI_FAILURE(status))
buffer.pointer = NULL;
dev->pnp.str_obj = buffer.pointer;
result = device_create_file(&dev->dev, &dev_attr_description);
if (result)
goto end;
}
if (dev->pnp.type.bus_address)
result = device_create_file(&dev->dev, &dev_attr_adr);
if (dev->pnp.unique_id)
result = device_create_file(&dev->dev, &dev_attr_uid);
if (acpi_has_method(dev->handle, "_SUN")) {
result = device_create_file(&dev->dev, &dev_attr_sun);
if (result)
goto end;
}
if (acpi_has_method(dev->handle, "_HRV")) {
result = device_create_file(&dev->dev, &dev_attr_hrv);
if (result)
goto end;
}
if (acpi_has_method(dev->handle, "_STA")) {
result = device_create_file(&dev->dev, &dev_attr_status);
if (result)
goto end;
}
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
*/
if (acpi_has_method(dev->handle, "_EJ0")) {
result = device_create_file(&dev->dev, &dev_attr_eject);
if (result)
return result;
}
if (dev->flags.power_manageable) {
result = device_create_file(&dev->dev, &dev_attr_power_state);
if (result)
return result;
if (dev->power.flags.power_resources)
result = device_create_file(&dev->dev,
&dev_attr_real_power_state);
}
acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
end:
return result;
}
/**
* acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
* @dev: ACPI device object.
*/
void acpi_device_remove_files(struct acpi_device *dev)
{
acpi_hide_nondev_subnodes(&dev->data);
if (dev->flags.power_manageable) {
device_remove_file(&dev->dev, &dev_attr_power_state);
if (dev->power.flags.power_resources)
device_remove_file(&dev->dev,
&dev_attr_real_power_state);
}
/*
* If device has _STR, remove 'description' file
*/
if (acpi_has_method(dev->handle, "_STR")) {
kfree(dev->pnp.str_obj);
device_remove_file(&dev->dev, &dev_attr_description);
}
/*
* If device has _EJ0, remove 'eject' file.
*/
if (acpi_has_method(dev->handle, "_EJ0"))
device_remove_file(&dev->dev, &dev_attr_eject);
if (acpi_has_method(dev->handle, "_SUN"))
device_remove_file(&dev->dev, &dev_attr_sun);
if (acpi_has_method(dev->handle, "_HRV"))
device_remove_file(&dev->dev, &dev_attr_hrv);
if (dev->pnp.unique_id)
device_remove_file(&dev->dev, &dev_attr_uid);
if (dev->pnp.type.bus_address)
device_remove_file(&dev->dev, &dev_attr_adr);
device_remove_file(&dev->dev, &dev_attr_modalias);
device_remove_file(&dev->dev, &dev_attr_hid);
if (acpi_has_method(dev->handle, "_STA"))
device_remove_file(&dev->dev, &dev_attr_status);
if (dev->handle)
device_remove_file(&dev->dev, &dev_attr_path);
}