linux/drivers/gpu/drm/drm_drv.c
Jani Nikula 7fb8af6798 drm: deprecate driver date
The driver date serves no useful purpose, because it's hardly ever
updated. The information is misleading at best.

As described in Documentation/gpu/drm-internals.rst:

  The driver date, formatted as YYYYMMDD, is meant to identify the date
  of the latest modification to the driver. However, as most drivers
  fail to update it, its value is mostly useless. The DRM core prints it
  to the kernel log at initialization time and passes it to userspace
  through the DRM_IOCTL_VERSION ioctl.

Stop printing the driver date at init, and start returning the empty
string "" as driver date through the DRM_IOCTL_VERSION ioctl.

The driver date initialization in drivers and the struct drm_driver date
member can be removed in follow-up.

Reviewed-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Acked-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240429164336.1406480-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2024-05-08 15:31:58 +03:00

1116 lines
30 KiB
C

/*
* Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
*
* Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
* All Rights Reserved.
*
* Author Rickard E. (Rik) Faith <faith@valinux.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mount.h>
#include <linux/pseudo_fs.h>
#include <linux/slab.h>
#include <linux/srcu.h>
#include <drm/drm_accel.h>
#include <drm/drm_cache.h>
#include <drm/drm_client.h>
#include <drm/drm_color_mgmt.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_managed.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_panic.h>
#include <drm/drm_print.h>
#include <drm/drm_privacy_screen_machine.h>
#include "drm_crtc_internal.h"
#include "drm_internal.h"
MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
MODULE_DESCRIPTION("DRM shared core routines");
MODULE_LICENSE("GPL and additional rights");
static DEFINE_SPINLOCK(drm_minor_lock);
static struct idr drm_minors_idr;
/*
* If the drm core fails to init for whatever reason,
* we should prevent any drivers from registering with it.
* It's best to check this at drm_dev_init(), as some drivers
* prefer to embed struct drm_device into their own device
* structure and call drm_dev_init() themselves.
*/
static bool drm_core_init_complete;
static struct dentry *drm_debugfs_root;
DEFINE_STATIC_SRCU(drm_unplug_srcu);
/*
* DRM Minors
* A DRM device can provide several char-dev interfaces on the DRM-Major. Each
* of them is represented by a drm_minor object. Depending on the capabilities
* of the device-driver, different interfaces are registered.
*
* Minors can be accessed via dev->$minor_name. This pointer is either
* NULL or a valid drm_minor pointer and stays valid as long as the device is
* valid. This means, DRM minors have the same life-time as the underlying
* device. However, this doesn't mean that the minor is active. Minors are
* registered and unregistered dynamically according to device-state.
*/
static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
enum drm_minor_type type)
{
switch (type) {
case DRM_MINOR_PRIMARY:
return &dev->primary;
case DRM_MINOR_RENDER:
return &dev->render;
case DRM_MINOR_ACCEL:
return &dev->accel;
default:
BUG();
}
}
static void drm_minor_alloc_release(struct drm_device *dev, void *data)
{
struct drm_minor *minor = data;
unsigned long flags;
WARN_ON(dev != minor->dev);
put_device(minor->kdev);
if (minor->type == DRM_MINOR_ACCEL) {
accel_minor_remove(minor->index);
} else {
spin_lock_irqsave(&drm_minor_lock, flags);
idr_remove(&drm_minors_idr, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
}
}
static int drm_minor_alloc(struct drm_device *dev, enum drm_minor_type type)
{
struct drm_minor *minor;
unsigned long flags;
int r;
minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
if (!minor)
return -ENOMEM;
minor->type = type;
minor->dev = dev;
idr_preload(GFP_KERNEL);
if (type == DRM_MINOR_ACCEL) {
r = accel_minor_alloc();
} else {
spin_lock_irqsave(&drm_minor_lock, flags);
r = idr_alloc(&drm_minors_idr,
NULL,
64 * type,
64 * (type + 1),
GFP_NOWAIT);
spin_unlock_irqrestore(&drm_minor_lock, flags);
}
idr_preload_end();
if (r < 0)
return r;
minor->index = r;
r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
if (r)
return r;
minor->kdev = drm_sysfs_minor_alloc(minor);
if (IS_ERR(minor->kdev))
return PTR_ERR(minor->kdev);
*drm_minor_get_slot(dev, type) = minor;
return 0;
}
static int drm_minor_register(struct drm_device *dev, enum drm_minor_type type)
{
struct drm_minor *minor;
unsigned long flags;
int ret;
DRM_DEBUG("\n");
minor = *drm_minor_get_slot(dev, type);
if (!minor)
return 0;
if (minor->type != DRM_MINOR_ACCEL) {
ret = drm_debugfs_register(minor, minor->index,
drm_debugfs_root);
if (ret) {
DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
goto err_debugfs;
}
}
ret = device_add(minor->kdev);
if (ret)
goto err_debugfs;
/* replace NULL with @minor so lookups will succeed from now on */
if (minor->type == DRM_MINOR_ACCEL) {
accel_minor_replace(minor, minor->index);
} else {
spin_lock_irqsave(&drm_minor_lock, flags);
idr_replace(&drm_minors_idr, minor, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
}
DRM_DEBUG("new minor registered %d\n", minor->index);
return 0;
err_debugfs:
drm_debugfs_unregister(minor);
return ret;
}
static void drm_minor_unregister(struct drm_device *dev, enum drm_minor_type type)
{
struct drm_minor *minor;
unsigned long flags;
minor = *drm_minor_get_slot(dev, type);
if (!minor || !device_is_registered(minor->kdev))
return;
/* replace @minor with NULL so lookups will fail from now on */
if (minor->type == DRM_MINOR_ACCEL) {
accel_minor_replace(NULL, minor->index);
} else {
spin_lock_irqsave(&drm_minor_lock, flags);
idr_replace(&drm_minors_idr, NULL, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
}
device_del(minor->kdev);
dev_set_drvdata(minor->kdev, NULL); /* safety belt */
drm_debugfs_unregister(minor);
}
/*
* Looks up the given minor-ID and returns the respective DRM-minor object. The
* refence-count of the underlying device is increased so you must release this
* object with drm_minor_release().
*
* As long as you hold this minor, it is guaranteed that the object and the
* minor->dev pointer will stay valid! However, the device may get unplugged and
* unregistered while you hold the minor.
*/
struct drm_minor *drm_minor_acquire(unsigned int minor_id)
{
struct drm_minor *minor;
unsigned long flags;
spin_lock_irqsave(&drm_minor_lock, flags);
minor = idr_find(&drm_minors_idr, minor_id);
if (minor)
drm_dev_get(minor->dev);
spin_unlock_irqrestore(&drm_minor_lock, flags);
if (!minor) {
return ERR_PTR(-ENODEV);
} else if (drm_dev_is_unplugged(minor->dev)) {
drm_dev_put(minor->dev);
return ERR_PTR(-ENODEV);
}
return minor;
}
void drm_minor_release(struct drm_minor *minor)
{
drm_dev_put(minor->dev);
}
/**
* DOC: driver instance overview
*
* A device instance for a drm driver is represented by &struct drm_device. This
* is allocated and initialized with devm_drm_dev_alloc(), usually from
* bus-specific ->probe() callbacks implemented by the driver. The driver then
* needs to initialize all the various subsystems for the drm device like memory
* management, vblank handling, modesetting support and initial output
* configuration plus obviously initialize all the corresponding hardware bits.
* Finally when everything is up and running and ready for userspace the device
* instance can be published using drm_dev_register().
*
* There is also deprecated support for initializing device instances using
* bus-specific helpers and the &drm_driver.load callback. But due to
* backwards-compatibility needs the device instance have to be published too
* early, which requires unpretty global locking to make safe and is therefore
* only support for existing drivers not yet converted to the new scheme.
*
* When cleaning up a device instance everything needs to be done in reverse:
* First unpublish the device instance with drm_dev_unregister(). Then clean up
* any other resources allocated at device initialization and drop the driver's
* reference to &drm_device using drm_dev_put().
*
* Note that any allocation or resource which is visible to userspace must be
* released only when the final drm_dev_put() is called, and not when the
* driver is unbound from the underlying physical struct &device. Best to use
* &drm_device managed resources with drmm_add_action(), drmm_kmalloc() and
* related functions.
*
* devres managed resources like devm_kmalloc() can only be used for resources
* directly related to the underlying hardware device, and only used in code
* paths fully protected by drm_dev_enter() and drm_dev_exit().
*
* Display driver example
* ~~~~~~~~~~~~~~~~~~~~~~
*
* The following example shows a typical structure of a DRM display driver.
* The example focus on the probe() function and the other functions that is
* almost always present and serves as a demonstration of devm_drm_dev_alloc().
*
* .. code-block:: c
*
* struct driver_device {
* struct drm_device drm;
* void *userspace_facing;
* struct clk *pclk;
* };
*
* static const struct drm_driver driver_drm_driver = {
* [...]
* };
*
* static int driver_probe(struct platform_device *pdev)
* {
* struct driver_device *priv;
* struct drm_device *drm;
* int ret;
*
* priv = devm_drm_dev_alloc(&pdev->dev, &driver_drm_driver,
* struct driver_device, drm);
* if (IS_ERR(priv))
* return PTR_ERR(priv);
* drm = &priv->drm;
*
* ret = drmm_mode_config_init(drm);
* if (ret)
* return ret;
*
* priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
* if (!priv->userspace_facing)
* return -ENOMEM;
*
* priv->pclk = devm_clk_get(dev, "PCLK");
* if (IS_ERR(priv->pclk))
* return PTR_ERR(priv->pclk);
*
* // Further setup, display pipeline etc
*
* platform_set_drvdata(pdev, drm);
*
* drm_mode_config_reset(drm);
*
* ret = drm_dev_register(drm);
* if (ret)
* return ret;
*
* drm_fbdev_{...}_setup(drm, 32);
*
* return 0;
* }
*
* // This function is called before the devm_ resources are released
* static int driver_remove(struct platform_device *pdev)
* {
* struct drm_device *drm = platform_get_drvdata(pdev);
*
* drm_dev_unregister(drm);
* drm_atomic_helper_shutdown(drm)
*
* return 0;
* }
*
* // This function is called on kernel restart and shutdown
* static void driver_shutdown(struct platform_device *pdev)
* {
* drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
* }
*
* static int __maybe_unused driver_pm_suspend(struct device *dev)
* {
* return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
* }
*
* static int __maybe_unused driver_pm_resume(struct device *dev)
* {
* drm_mode_config_helper_resume(dev_get_drvdata(dev));
*
* return 0;
* }
*
* static const struct dev_pm_ops driver_pm_ops = {
* SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
* };
*
* static struct platform_driver driver_driver = {
* .driver = {
* [...]
* .pm = &driver_pm_ops,
* },
* .probe = driver_probe,
* .remove = driver_remove,
* .shutdown = driver_shutdown,
* };
* module_platform_driver(driver_driver);
*
* Drivers that want to support device unplugging (USB, DT overlay unload) should
* use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
* regions that is accessing device resources to prevent use after they're
* released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
* shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
* drm_atomic_helper_shutdown() is called. This means that if the disable code
* paths are protected, they will not run on regular driver module unload,
* possibly leaving the hardware enabled.
*/
/**
* drm_put_dev - Unregister and release a DRM device
* @dev: DRM device
*
* Called at module unload time or when a PCI device is unplugged.
*
* Cleans up all DRM device, calling drm_lastclose().
*
* Note: Use of this function is deprecated. It will eventually go away
* completely. Please use drm_dev_unregister() and drm_dev_put() explicitly
* instead to make sure that the device isn't userspace accessible any more
* while teardown is in progress, ensuring that userspace can't access an
* inconsistent state.
*/
void drm_put_dev(struct drm_device *dev)
{
DRM_DEBUG("\n");
if (!dev) {
DRM_ERROR("cleanup called no dev\n");
return;
}
drm_dev_unregister(dev);
drm_dev_put(dev);
}
EXPORT_SYMBOL(drm_put_dev);
/**
* drm_dev_enter - Enter device critical section
* @dev: DRM device
* @idx: Pointer to index that will be passed to the matching drm_dev_exit()
*
* This function marks and protects the beginning of a section that should not
* be entered after the device has been unplugged. The section end is marked
* with drm_dev_exit(). Calls to this function can be nested.
*
* Returns:
* True if it is OK to enter the section, false otherwise.
*/
bool drm_dev_enter(struct drm_device *dev, int *idx)
{
*idx = srcu_read_lock(&drm_unplug_srcu);
if (dev->unplugged) {
srcu_read_unlock(&drm_unplug_srcu, *idx);
return false;
}
return true;
}
EXPORT_SYMBOL(drm_dev_enter);
/**
* drm_dev_exit - Exit device critical section
* @idx: index returned from drm_dev_enter()
*
* This function marks the end of a section that should not be entered after
* the device has been unplugged.
*/
void drm_dev_exit(int idx)
{
srcu_read_unlock(&drm_unplug_srcu, idx);
}
EXPORT_SYMBOL(drm_dev_exit);
/**
* drm_dev_unplug - unplug a DRM device
* @dev: DRM device
*
* This unplugs a hotpluggable DRM device, which makes it inaccessible to
* userspace operations. Entry-points can use drm_dev_enter() and
* drm_dev_exit() to protect device resources in a race free manner. This
* essentially unregisters the device like drm_dev_unregister(), but can be
* called while there are still open users of @dev.
*/
void drm_dev_unplug(struct drm_device *dev)
{
/*
* After synchronizing any critical read section is guaranteed to see
* the new value of ->unplugged, and any critical section which might
* still have seen the old value of ->unplugged is guaranteed to have
* finished.
*/
dev->unplugged = true;
synchronize_srcu(&drm_unplug_srcu);
drm_dev_unregister(dev);
/* Clear all CPU mappings pointing to this device */
unmap_mapping_range(dev->anon_inode->i_mapping, 0, 0, 1);
}
EXPORT_SYMBOL(drm_dev_unplug);
/*
* DRM internal mount
* We want to be able to allocate our own "struct address_space" to control
* memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
* stand-alone address_space objects, so we need an underlying inode. As there
* is no way to allocate an independent inode easily, we need a fake internal
* VFS mount-point.
*
* The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
* frees it again. You are allowed to use iget() and iput() to get references to
* the inode. But each drm_fs_inode_new() call must be paired with exactly one
* drm_fs_inode_free() call (which does not have to be the last iput()).
* We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
* between multiple inode-users. You could, technically, call
* iget() + drm_fs_inode_free() directly after alloc and sometime later do an
* iput(), but this way you'd end up with a new vfsmount for each inode.
*/
static int drm_fs_cnt;
static struct vfsmount *drm_fs_mnt;
static int drm_fs_init_fs_context(struct fs_context *fc)
{
return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
}
static struct file_system_type drm_fs_type = {
.name = "drm",
.owner = THIS_MODULE,
.init_fs_context = drm_fs_init_fs_context,
.kill_sb = kill_anon_super,
};
static struct inode *drm_fs_inode_new(void)
{
struct inode *inode;
int r;
r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
if (r < 0) {
DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
return ERR_PTR(r);
}
inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
if (IS_ERR(inode))
simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
return inode;
}
static void drm_fs_inode_free(struct inode *inode)
{
if (inode) {
iput(inode);
simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
}
}
/**
* DOC: component helper usage recommendations
*
* DRM drivers that drive hardware where a logical device consists of a pile of
* independent hardware blocks are recommended to use the :ref:`component helper
* library<component>`. For consistency and better options for code reuse the
* following guidelines apply:
*
* - The entire device initialization procedure should be run from the
* &component_master_ops.master_bind callback, starting with
* devm_drm_dev_alloc(), then binding all components with
* component_bind_all() and finishing with drm_dev_register().
*
* - The opaque pointer passed to all components through component_bind_all()
* should point at &struct drm_device of the device instance, not some driver
* specific private structure.
*
* - The component helper fills the niche where further standardization of
* interfaces is not practical. When there already is, or will be, a
* standardized interface like &drm_bridge or &drm_panel, providing its own
* functions to find such components at driver load time, like
* drm_of_find_panel_or_bridge(), then the component helper should not be
* used.
*/
static void drm_dev_init_release(struct drm_device *dev, void *res)
{
drm_fs_inode_free(dev->anon_inode);
put_device(dev->dev);
/* Prevent use-after-free in drm_managed_release when debugging is
* enabled. Slightly awkward, but can't really be helped. */
dev->dev = NULL;
mutex_destroy(&dev->master_mutex);
mutex_destroy(&dev->clientlist_mutex);
mutex_destroy(&dev->filelist_mutex);
mutex_destroy(&dev->struct_mutex);
}
static int drm_dev_init(struct drm_device *dev,
const struct drm_driver *driver,
struct device *parent)
{
struct inode *inode;
int ret;
if (!drm_core_init_complete) {
DRM_ERROR("DRM core is not initialized\n");
return -ENODEV;
}
if (WARN_ON(!parent))
return -EINVAL;
kref_init(&dev->ref);
dev->dev = get_device(parent);
dev->driver = driver;
INIT_LIST_HEAD(&dev->managed.resources);
spin_lock_init(&dev->managed.lock);
/* no per-device feature limits by default */
dev->driver_features = ~0u;
if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL) &&
(drm_core_check_feature(dev, DRIVER_RENDER) ||
drm_core_check_feature(dev, DRIVER_MODESET))) {
DRM_ERROR("DRM driver can't be both a compute acceleration and graphics driver\n");
return -EINVAL;
}
INIT_LIST_HEAD(&dev->filelist);
INIT_LIST_HEAD(&dev->filelist_internal);
INIT_LIST_HEAD(&dev->clientlist);
INIT_LIST_HEAD(&dev->vblank_event_list);
spin_lock_init(&dev->event_lock);
mutex_init(&dev->struct_mutex);
mutex_init(&dev->filelist_mutex);
mutex_init(&dev->clientlist_mutex);
mutex_init(&dev->master_mutex);
raw_spin_lock_init(&dev->mode_config.panic_lock);
ret = drmm_add_action_or_reset(dev, drm_dev_init_release, NULL);
if (ret)
return ret;
inode = drm_fs_inode_new();
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
goto err;
}
dev->anon_inode = inode;
if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL)) {
ret = drm_minor_alloc(dev, DRM_MINOR_ACCEL);
if (ret)
goto err;
} else {
if (drm_core_check_feature(dev, DRIVER_RENDER)) {
ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
if (ret)
goto err;
}
ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
if (ret)
goto err;
}
if (drm_core_check_feature(dev, DRIVER_GEM)) {
ret = drm_gem_init(dev);
if (ret) {
DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
goto err;
}
}
dev->unique = drmm_kstrdup(dev, dev_name(parent), GFP_KERNEL);
if (!dev->unique) {
ret = -ENOMEM;
goto err;
}
if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL))
accel_debugfs_init(dev);
else
drm_debugfs_dev_init(dev, drm_debugfs_root);
return 0;
err:
drm_managed_release(dev);
return ret;
}
static void devm_drm_dev_init_release(void *data)
{
drm_dev_put(data);
}
static int devm_drm_dev_init(struct device *parent,
struct drm_device *dev,
const struct drm_driver *driver)
{
int ret;
ret = drm_dev_init(dev, driver, parent);
if (ret)
return ret;
return devm_add_action_or_reset(parent,
devm_drm_dev_init_release, dev);
}
void *__devm_drm_dev_alloc(struct device *parent,
const struct drm_driver *driver,
size_t size, size_t offset)
{
void *container;
struct drm_device *drm;
int ret;
container = kzalloc(size, GFP_KERNEL);
if (!container)
return ERR_PTR(-ENOMEM);
drm = container + offset;
ret = devm_drm_dev_init(parent, drm, driver);
if (ret) {
kfree(container);
return ERR_PTR(ret);
}
drmm_add_final_kfree(drm, container);
return container;
}
EXPORT_SYMBOL(__devm_drm_dev_alloc);
/**
* drm_dev_alloc - Allocate new DRM device
* @driver: DRM driver to allocate device for
* @parent: Parent device object
*
* This is the deprecated version of devm_drm_dev_alloc(), which does not support
* subclassing through embedding the struct &drm_device in a driver private
* structure, and which does not support automatic cleanup through devres.
*
* RETURNS:
* Pointer to new DRM device, or ERR_PTR on failure.
*/
struct drm_device *drm_dev_alloc(const struct drm_driver *driver,
struct device *parent)
{
struct drm_device *dev;
int ret;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return ERR_PTR(-ENOMEM);
ret = drm_dev_init(dev, driver, parent);
if (ret) {
kfree(dev);
return ERR_PTR(ret);
}
drmm_add_final_kfree(dev, dev);
return dev;
}
EXPORT_SYMBOL(drm_dev_alloc);
static void drm_dev_release(struct kref *ref)
{
struct drm_device *dev = container_of(ref, struct drm_device, ref);
/* Just in case register/unregister was never called */
drm_debugfs_dev_fini(dev);
if (dev->driver->release)
dev->driver->release(dev);
drm_managed_release(dev);
kfree(dev->managed.final_kfree);
}
/**
* drm_dev_get - Take reference of a DRM device
* @dev: device to take reference of or NULL
*
* This increases the ref-count of @dev by one. You *must* already own a
* reference when calling this. Use drm_dev_put() to drop this reference
* again.
*
* This function never fails. However, this function does not provide *any*
* guarantee whether the device is alive or running. It only provides a
* reference to the object and the memory associated with it.
*/
void drm_dev_get(struct drm_device *dev)
{
if (dev)
kref_get(&dev->ref);
}
EXPORT_SYMBOL(drm_dev_get);
/**
* drm_dev_put - Drop reference of a DRM device
* @dev: device to drop reference of or NULL
*
* This decreases the ref-count of @dev by one. The device is destroyed if the
* ref-count drops to zero.
*/
void drm_dev_put(struct drm_device *dev)
{
if (dev)
kref_put(&dev->ref, drm_dev_release);
}
EXPORT_SYMBOL(drm_dev_put);
static int create_compat_control_link(struct drm_device *dev)
{
struct drm_minor *minor;
char *name;
int ret;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
if (!minor)
return 0;
/*
* Some existing userspace out there uses the existing of the controlD*
* sysfs files to figure out whether it's a modeset driver. It only does
* readdir, hence a symlink is sufficient (and the least confusing
* option). Otherwise controlD* is entirely unused.
*
* Old controlD chardev have been allocated in the range
* 64-127.
*/
name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
if (!name)
return -ENOMEM;
ret = sysfs_create_link(minor->kdev->kobj.parent,
&minor->kdev->kobj,
name);
kfree(name);
return ret;
}
static void remove_compat_control_link(struct drm_device *dev)
{
struct drm_minor *minor;
char *name;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return;
minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
if (!minor)
return;
name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
if (!name)
return;
sysfs_remove_link(minor->kdev->kobj.parent, name);
kfree(name);
}
/**
* drm_dev_register - Register DRM device
* @dev: Device to register
* @flags: Flags passed to the driver's .load() function
*
* Register the DRM device @dev with the system, advertise device to user-space
* and start normal device operation. @dev must be initialized via drm_dev_init()
* previously.
*
* Never call this twice on any device!
*
* NOTE: To ensure backward compatibility with existing drivers method this
* function calls the &drm_driver.load method after registering the device
* nodes, creating race conditions. Usage of the &drm_driver.load methods is
* therefore deprecated, drivers must perform all initialization before calling
* drm_dev_register().
*
* RETURNS:
* 0 on success, negative error code on failure.
*/
int drm_dev_register(struct drm_device *dev, unsigned long flags)
{
const struct drm_driver *driver = dev->driver;
int ret;
if (!driver->load)
drm_mode_config_validate(dev);
WARN_ON(!dev->managed.final_kfree);
if (drm_dev_needs_global_mutex(dev))
mutex_lock(&drm_global_mutex);
if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL))
accel_debugfs_register(dev);
else
drm_debugfs_dev_register(dev);
ret = drm_minor_register(dev, DRM_MINOR_RENDER);
if (ret)
goto err_minors;
ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
if (ret)
goto err_minors;
ret = drm_minor_register(dev, DRM_MINOR_ACCEL);
if (ret)
goto err_minors;
ret = create_compat_control_link(dev);
if (ret)
goto err_minors;
dev->registered = true;
if (driver->load) {
ret = driver->load(dev, flags);
if (ret)
goto err_minors;
}
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
ret = drm_modeset_register_all(dev);
if (ret)
goto err_unload;
}
drm_panic_register(dev);
DRM_INFO("Initialized %s %d.%d.%d for %s on minor %d\n",
driver->name, driver->major, driver->minor,
driver->patchlevel,
dev->dev ? dev_name(dev->dev) : "virtual device",
dev->primary ? dev->primary->index : dev->accel->index);
goto out_unlock;
err_unload:
if (dev->driver->unload)
dev->driver->unload(dev);
err_minors:
remove_compat_control_link(dev);
drm_minor_unregister(dev, DRM_MINOR_ACCEL);
drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
out_unlock:
if (drm_dev_needs_global_mutex(dev))
mutex_unlock(&drm_global_mutex);
return ret;
}
EXPORT_SYMBOL(drm_dev_register);
/**
* drm_dev_unregister - Unregister DRM device
* @dev: Device to unregister
*
* Unregister the DRM device from the system. This does the reverse of
* drm_dev_register() but does not deallocate the device. The caller must call
* drm_dev_put() to drop their final reference, unless it is managed with devres
* (as devices allocated with devm_drm_dev_alloc() are), in which case there is
* already an unwind action registered.
*
* A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
* which can be called while there are still open users of @dev.
*
* This should be called first in the device teardown code to make sure
* userspace can't access the device instance any more.
*/
void drm_dev_unregister(struct drm_device *dev)
{
dev->registered = false;
drm_panic_unregister(dev);
drm_client_dev_unregister(dev);
if (drm_core_check_feature(dev, DRIVER_MODESET))
drm_modeset_unregister_all(dev);
if (dev->driver->unload)
dev->driver->unload(dev);
remove_compat_control_link(dev);
drm_minor_unregister(dev, DRM_MINOR_ACCEL);
drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
drm_debugfs_dev_fini(dev);
}
EXPORT_SYMBOL(drm_dev_unregister);
/*
* DRM Core
* The DRM core module initializes all global DRM objects and makes them
* available to drivers. Once setup, drivers can probe their respective
* devices.
* Currently, core management includes:
* - The "DRM-Global" key/value database
* - Global ID management for connectors
* - DRM major number allocation
* - DRM minor management
* - DRM sysfs class
* - DRM debugfs root
*
* Furthermore, the DRM core provides dynamic char-dev lookups. For each
* interface registered on a DRM device, you can request minor numbers from DRM
* core. DRM core takes care of major-number management and char-dev
* registration. A stub ->open() callback forwards any open() requests to the
* registered minor.
*/
static int drm_stub_open(struct inode *inode, struct file *filp)
{
const struct file_operations *new_fops;
struct drm_minor *minor;
int err;
DRM_DEBUG("\n");
minor = drm_minor_acquire(iminor(inode));
if (IS_ERR(minor))
return PTR_ERR(minor);
new_fops = fops_get(minor->dev->driver->fops);
if (!new_fops) {
err = -ENODEV;
goto out;
}
replace_fops(filp, new_fops);
if (filp->f_op->open)
err = filp->f_op->open(inode, filp);
else
err = 0;
out:
drm_minor_release(minor);
return err;
}
static const struct file_operations drm_stub_fops = {
.owner = THIS_MODULE,
.open = drm_stub_open,
.llseek = noop_llseek,
};
static void drm_core_exit(void)
{
drm_privacy_screen_lookup_exit();
accel_core_exit();
unregister_chrdev(DRM_MAJOR, "drm");
debugfs_remove(drm_debugfs_root);
drm_sysfs_destroy();
idr_destroy(&drm_minors_idr);
drm_connector_ida_destroy();
}
static int __init drm_core_init(void)
{
int ret;
drm_connector_ida_init();
idr_init(&drm_minors_idr);
drm_memcpy_init_early();
ret = drm_sysfs_init();
if (ret < 0) {
DRM_ERROR("Cannot create DRM class: %d\n", ret);
goto error;
}
drm_debugfs_root = debugfs_create_dir("dri", NULL);
ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
if (ret < 0)
goto error;
ret = accel_core_init();
if (ret < 0)
goto error;
drm_privacy_screen_lookup_init();
drm_core_init_complete = true;
DRM_DEBUG("Initialized\n");
return 0;
error:
drm_core_exit();
return ret;
}
module_init(drm_core_init);
module_exit(drm_core_exit);