linux_dsm_epyc7002/drivers/gpu/drm/drm_sysfs.c
Daniel Vetter 4eb9b945c6 drm/sysfs: Annote lockless show functions with READ_ONCE
For documentation and paranoia.

Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331120-27864-4-git-send-email-daniel.vetter@ffwll.ch
2016-04-26 13:23:24 +02:00

488 lines
12 KiB
C

/*
* drm_sysfs.c - Modifications to drm_sysfs_class.c to support
* extra sysfs attribute from DRM. Normal drm_sysfs_class
* does not allow adding attributes.
*
* Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
* Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2003-2004 IBM Corp.
*
* This file is released under the GPLv2
*
*/
#include <linux/device.h>
#include <linux/kdev_t.h>
#include <linux/gfp.h>
#include <linux/err.h>
#include <linux/export.h>
#include <drm/drm_sysfs.h>
#include <drm/drm_core.h>
#include <drm/drmP.h>
#include "drm_internal.h"
#define to_drm_minor(d) dev_get_drvdata(d)
#define to_drm_connector(d) dev_get_drvdata(d)
static struct device_type drm_sysfs_device_minor = {
.name = "drm_minor"
};
struct class *drm_class;
/**
* __drm_class_suspend - internal DRM class suspend routine
* @dev: Linux device to suspend
* @state: power state to enter
*
* Just figures out what the actual struct drm_device associated with
* @dev is and calls its suspend hook, if present.
*/
static int __drm_class_suspend(struct device *dev, pm_message_t state)
{
if (dev->type == &drm_sysfs_device_minor) {
struct drm_minor *drm_minor = to_drm_minor(dev);
struct drm_device *drm_dev = drm_minor->dev;
if (drm_minor->type == DRM_MINOR_LEGACY &&
!drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
drm_dev->driver->suspend)
return drm_dev->driver->suspend(drm_dev, state);
}
return 0;
}
/**
* drm_class_suspend - internal DRM class suspend hook. Simply calls
* __drm_class_suspend() with the correct pm state.
* @dev: Linux device to suspend
*/
static int drm_class_suspend(struct device *dev)
{
return __drm_class_suspend(dev, PMSG_SUSPEND);
}
/**
* drm_class_freeze - internal DRM class freeze hook. Simply calls
* __drm_class_suspend() with the correct pm state.
* @dev: Linux device to freeze
*/
static int drm_class_freeze(struct device *dev)
{
return __drm_class_suspend(dev, PMSG_FREEZE);
}
/**
* drm_class_resume - DRM class resume hook
* @dev: Linux device to resume
*
* Just figures out what the actual struct drm_device associated with
* @dev is and calls its resume hook, if present.
*/
static int drm_class_resume(struct device *dev)
{
if (dev->type == &drm_sysfs_device_minor) {
struct drm_minor *drm_minor = to_drm_minor(dev);
struct drm_device *drm_dev = drm_minor->dev;
if (drm_minor->type == DRM_MINOR_LEGACY &&
!drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
drm_dev->driver->resume)
return drm_dev->driver->resume(drm_dev);
}
return 0;
}
static const struct dev_pm_ops drm_class_dev_pm_ops = {
.suspend = drm_class_suspend,
.resume = drm_class_resume,
.freeze = drm_class_freeze,
};
static char *drm_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
}
static CLASS_ATTR_STRING(version, S_IRUGO,
CORE_NAME " "
__stringify(CORE_MAJOR) "."
__stringify(CORE_MINOR) "."
__stringify(CORE_PATCHLEVEL) " "
CORE_DATE);
/**
* drm_sysfs_init - initialize sysfs helpers
*
* This is used to create the DRM class, which is the implicit parent of any
* other top-level DRM sysfs objects.
*
* You must call drm_sysfs_destroy() to release the allocated resources.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_sysfs_init(void)
{
int err;
drm_class = class_create(THIS_MODULE, "drm");
if (IS_ERR(drm_class))
return PTR_ERR(drm_class);
drm_class->pm = &drm_class_dev_pm_ops;
err = class_create_file(drm_class, &class_attr_version.attr);
if (err) {
class_destroy(drm_class);
drm_class = NULL;
return err;
}
drm_class->devnode = drm_devnode;
return 0;
}
/**
* drm_sysfs_destroy - destroys DRM class
*
* Destroy the DRM device class.
*/
void drm_sysfs_destroy(void)
{
if (IS_ERR_OR_NULL(drm_class))
return;
class_remove_file(drm_class, &class_attr_version.attr);
class_destroy(drm_class);
drm_class = NULL;
}
/*
* Connector properties
*/
static ssize_t status_store(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_device *dev = connector->dev;
enum drm_connector_force old_force;
int ret;
ret = mutex_lock_interruptible(&dev->mode_config.mutex);
if (ret)
return ret;
old_force = connector->force;
if (sysfs_streq(buf, "detect"))
connector->force = 0;
else if (sysfs_streq(buf, "on"))
connector->force = DRM_FORCE_ON;
else if (sysfs_streq(buf, "on-digital"))
connector->force = DRM_FORCE_ON_DIGITAL;
else if (sysfs_streq(buf, "off"))
connector->force = DRM_FORCE_OFF;
else
ret = -EINVAL;
if (old_force != connector->force || !connector->force) {
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
connector->base.id,
connector->name,
old_force, connector->force);
connector->funcs->fill_modes(connector,
dev->mode_config.max_width,
dev->mode_config.max_height);
}
mutex_unlock(&dev->mode_config.mutex);
return ret ? ret : count;
}
static ssize_t status_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
enum drm_connector_status status;
status = READ_ONCE(connector->status);
return snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_connector_status_name(status));
}
static ssize_t dpms_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
int dpms;
dpms = READ_ONCE(connector->dpms);
return snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_dpms_name(dpms));
}
static ssize_t enabled_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
bool enabled;
enabled = READ_ONCE(connector->encoder);
return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
}
static ssize_t edid_show(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *connector_dev = kobj_to_dev(kobj);
struct drm_connector *connector = to_drm_connector(connector_dev);
unsigned char *edid;
size_t size;
ssize_t ret = 0;
mutex_lock(&connector->dev->mode_config.mutex);
if (!connector->edid_blob_ptr)
goto unlock;
edid = connector->edid_blob_ptr->data;
size = connector->edid_blob_ptr->length;
if (!edid)
goto unlock;
if (off >= size)
goto unlock;
if (off + count > size)
count = size - off;
memcpy(buf, edid + off, count);
ret = count;
unlock:
mutex_unlock(&connector->dev->mode_config.mutex);
return ret;
}
static ssize_t modes_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_display_mode *mode;
int written = 0;
mutex_lock(&connector->dev->mode_config.mutex);
list_for_each_entry(mode, &connector->modes, head) {
written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
mode->name);
}
mutex_unlock(&connector->dev->mode_config.mutex);
return written;
}
static DEVICE_ATTR_RW(status);
static DEVICE_ATTR_RO(enabled);
static DEVICE_ATTR_RO(dpms);
static DEVICE_ATTR_RO(modes);
static struct attribute *connector_dev_attrs[] = {
&dev_attr_status.attr,
&dev_attr_enabled.attr,
&dev_attr_dpms.attr,
&dev_attr_modes.attr,
NULL
};
static struct bin_attribute edid_attr = {
.attr.name = "edid",
.attr.mode = 0444,
.size = 0,
.read = edid_show,
};
static struct bin_attribute *connector_bin_attrs[] = {
&edid_attr,
NULL
};
static const struct attribute_group connector_dev_group = {
.attrs = connector_dev_attrs,
.bin_attrs = connector_bin_attrs,
};
static const struct attribute_group *connector_dev_groups[] = {
&connector_dev_group,
NULL
};
/**
* drm_sysfs_connector_add - add a connector to sysfs
* @connector: connector to add
*
* Create a connector device in sysfs, along with its associated connector
* properties (so far, connection status, dpms, mode list & edid) and
* generate a hotplug event so userspace knows there's a new connector
* available.
*/
int drm_sysfs_connector_add(struct drm_connector *connector)
{
struct drm_device *dev = connector->dev;
if (connector->kdev)
return 0;
connector->kdev =
device_create_with_groups(drm_class, dev->primary->kdev, 0,
connector, connector_dev_groups,
"card%d-%s", dev->primary->index,
connector->name);
DRM_DEBUG("adding \"%s\" to sysfs\n",
connector->name);
if (IS_ERR(connector->kdev)) {
DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
return PTR_ERR(connector->kdev);
}
/* Let userspace know we have a new connector */
drm_sysfs_hotplug_event(dev);
return 0;
}
/**
* drm_sysfs_connector_remove - remove an connector device from sysfs
* @connector: connector to remove
*
* Remove @connector and its associated attributes from sysfs. Note that
* the device model core will take care of sending the "remove" uevent
* at this time, so we don't need to do it.
*
* Note:
* This routine should only be called if the connector was previously
* successfully registered. If @connector hasn't been registered yet,
* you'll likely see a panic somewhere deep in sysfs code when called.
*/
void drm_sysfs_connector_remove(struct drm_connector *connector)
{
if (!connector->kdev)
return;
DRM_DEBUG("removing \"%s\" from sysfs\n",
connector->name);
device_unregister(connector->kdev);
connector->kdev = NULL;
}
/**
* drm_sysfs_hotplug_event - generate a DRM uevent
* @dev: DRM device
*
* Send a uevent for the DRM device specified by @dev. Currently we only
* set HOTPLUG=1 in the uevent environment, but this could be expanded to
* deal with other types of events.
*/
void drm_sysfs_hotplug_event(struct drm_device *dev)
{
char *event_string = "HOTPLUG=1";
char *envp[] = { event_string, NULL };
DRM_DEBUG("generating hotplug event\n");
kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
}
EXPORT_SYMBOL(drm_sysfs_hotplug_event);
static void drm_sysfs_release(struct device *dev)
{
kfree(dev);
}
/**
* drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
* @minor: minor to allocate sysfs device for
*
* This allocates a new sysfs device for @minor and returns it. The device is
* not registered nor linked. The caller has to use device_add() and
* device_del() to register and unregister it.
*
* Note that dev_get_drvdata() on the new device will return the minor.
* However, the device does not hold a ref-count to the minor nor to the
* underlying drm_device. This is unproblematic as long as you access the
* private data only in sysfs callbacks. device_del() disables those
* synchronously, so they cannot be called after you cleanup a minor.
*/
struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
{
const char *minor_str;
struct device *kdev;
int r;
if (minor->type == DRM_MINOR_CONTROL)
minor_str = "controlD%d";
else if (minor->type == DRM_MINOR_RENDER)
minor_str = "renderD%d";
else
minor_str = "card%d";
kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
if (!kdev)
return ERR_PTR(-ENOMEM);
device_initialize(kdev);
kdev->devt = MKDEV(DRM_MAJOR, minor->index);
kdev->class = drm_class;
kdev->type = &drm_sysfs_device_minor;
kdev->parent = minor->dev->dev;
kdev->release = drm_sysfs_release;
dev_set_drvdata(kdev, minor);
r = dev_set_name(kdev, minor_str, minor->index);
if (r < 0)
goto err_free;
return kdev;
err_free:
put_device(kdev);
return ERR_PTR(r);
}
/**
* drm_class_device_register - Register a struct device in the drm class.
*
* @dev: pointer to struct device to register.
*
* @dev should have all relevant members pre-filled with the exception
* of the class member. In particular, the device_type member must
* be set.
*/
int drm_class_device_register(struct device *dev)
{
if (!drm_class || IS_ERR(drm_class))
return -ENOENT;
dev->class = drm_class;
return device_register(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_register);
void drm_class_device_unregister(struct device *dev)
{
return device_unregister(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_unregister);