linux-stable/drivers/gpu/drm/drm_drv.c
Thomas Hellstrom a0af2e538c drm: Fix an unwanted master inheritance v2
A client calling drmSetMaster() using a file descriptor that was opened
when another client was master would inherit the latter client's master
object and all its authenticated clients.

This is unwanted behaviour, and when this happens, instead allocate a
brand new master object for the client calling drmSetMaster().

Fixes a BUG() throw in vmw_master_set().

Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-12-04 12:28:14 +10:00

931 lines
24 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/slab.h>
#include <drm/drmP.h>
#include <drm/drm_core.h>
#include "drm_legacy.h"
#include "drm_internal.h"
unsigned int drm_debug = 0; /* bitmask of DRM_UT_x */
EXPORT_SYMBOL(drm_debug);
MODULE_AUTHOR(CORE_AUTHOR);
MODULE_DESCRIPTION(CORE_DESC);
MODULE_LICENSE("GPL and additional rights");
MODULE_PARM_DESC(debug, "Enable debug output");
MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
module_param_named(debug, drm_debug, int, 0600);
static DEFINE_SPINLOCK(drm_minor_lock);
static struct idr drm_minors_idr;
static struct dentry *drm_debugfs_root;
void drm_err(const char *format, ...)
{
struct va_format vaf;
va_list args;
va_start(args, format);
vaf.fmt = format;
vaf.va = &args;
printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
__builtin_return_address(0), &vaf);
va_end(args);
}
EXPORT_SYMBOL(drm_err);
void drm_ut_debug_printk(const char *function_name, const char *format, ...)
{
struct va_format vaf;
va_list args;
va_start(args, format);
vaf.fmt = format;
vaf.va = &args;
printk(KERN_DEBUG "[" DRM_NAME ":%s] %pV", function_name, &vaf);
va_end(args);
}
EXPORT_SYMBOL(drm_ut_debug_printk);
struct drm_master *drm_master_create(struct drm_minor *minor)
{
struct drm_master *master;
master = kzalloc(sizeof(*master), GFP_KERNEL);
if (!master)
return NULL;
kref_init(&master->refcount);
spin_lock_init(&master->lock.spinlock);
init_waitqueue_head(&master->lock.lock_queue);
idr_init(&master->magic_map);
master->minor = minor;
return master;
}
struct drm_master *drm_master_get(struct drm_master *master)
{
kref_get(&master->refcount);
return master;
}
EXPORT_SYMBOL(drm_master_get);
static void drm_master_destroy(struct kref *kref)
{
struct drm_master *master = container_of(kref, struct drm_master, refcount);
struct drm_device *dev = master->minor->dev;
struct drm_map_list *r_list, *list_temp;
mutex_lock(&dev->struct_mutex);
if (dev->driver->master_destroy)
dev->driver->master_destroy(dev, master);
list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
if (r_list->master == master) {
drm_legacy_rmmap_locked(dev, r_list->map);
r_list = NULL;
}
}
mutex_unlock(&dev->struct_mutex);
idr_destroy(&master->magic_map);
kfree(master->unique);
kfree(master);
}
void drm_master_put(struct drm_master **master)
{
kref_put(&(*master)->refcount, drm_master_destroy);
*master = NULL;
}
EXPORT_SYMBOL(drm_master_put);
int drm_setmaster_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
int ret = 0;
mutex_lock(&dev->master_mutex);
if (file_priv->is_master)
goto out_unlock;
if (file_priv->minor->master) {
ret = -EINVAL;
goto out_unlock;
}
if (!file_priv->master) {
ret = -EINVAL;
goto out_unlock;
}
if (!file_priv->allowed_master) {
ret = drm_new_set_master(dev, file_priv);
goto out_unlock;
}
file_priv->minor->master = drm_master_get(file_priv->master);
file_priv->is_master = 1;
if (dev->driver->master_set) {
ret = dev->driver->master_set(dev, file_priv, false);
if (unlikely(ret != 0)) {
file_priv->is_master = 0;
drm_master_put(&file_priv->minor->master);
}
}
out_unlock:
mutex_unlock(&dev->master_mutex);
return ret;
}
int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
int ret = -EINVAL;
mutex_lock(&dev->master_mutex);
if (!file_priv->is_master)
goto out_unlock;
if (!file_priv->minor->master)
goto out_unlock;
ret = 0;
if (dev->driver->master_drop)
dev->driver->master_drop(dev, file_priv, false);
drm_master_put(&file_priv->minor->master);
file_priv->is_master = 0;
out_unlock:
mutex_unlock(&dev->master_mutex);
return ret;
}
/*
* 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,
unsigned int type)
{
switch (type) {
case DRM_MINOR_LEGACY:
return &dev->primary;
case DRM_MINOR_RENDER:
return &dev->render;
case DRM_MINOR_CONTROL:
return &dev->control;
default:
return NULL;
}
}
static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
{
struct drm_minor *minor;
unsigned long flags;
int r;
minor = kzalloc(sizeof(*minor), GFP_KERNEL);
if (!minor)
return -ENOMEM;
minor->type = type;
minor->dev = dev;
idr_preload(GFP_KERNEL);
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)
goto err_free;
minor->index = r;
minor->kdev = drm_sysfs_minor_alloc(minor);
if (IS_ERR(minor->kdev)) {
r = PTR_ERR(minor->kdev);
goto err_index;
}
*drm_minor_get_slot(dev, type) = minor;
return 0;
err_index:
spin_lock_irqsave(&drm_minor_lock, flags);
idr_remove(&drm_minors_idr, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
err_free:
kfree(minor);
return r;
}
static void drm_minor_free(struct drm_device *dev, unsigned int type)
{
struct drm_minor **slot, *minor;
unsigned long flags;
slot = drm_minor_get_slot(dev, type);
minor = *slot;
if (!minor)
return;
put_device(minor->kdev);
spin_lock_irqsave(&drm_minor_lock, flags);
idr_remove(&drm_minors_idr, minor->index);
spin_unlock_irqrestore(&drm_minor_lock, flags);
kfree(minor);
*slot = NULL;
}
static int drm_minor_register(struct drm_device *dev, unsigned int type)
{
struct drm_minor *minor;
unsigned long flags;
int ret;
DRM_DEBUG("\n");
minor = *drm_minor_get_slot(dev, type);
if (!minor)
return 0;
ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
if (ret) {
DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
return ret;
}
ret = device_add(minor->kdev);
if (ret)
goto err_debugfs;
/* replace NULL with @minor so lookups will succeed from now on */
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_cleanup(minor);
return ret;
}
static void drm_minor_unregister(struct drm_device *dev, unsigned int 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 */
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_cleanup(minor);
}
/**
* drm_minor_acquire - Acquire a DRM minor
* @minor_id: Minor ID of the DRM-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.
*
* Returns:
* Pointer to minor-object with increased device-refcount, or PTR_ERR on
* failure.
*/
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_ref(minor->dev);
spin_unlock_irqrestore(&drm_minor_lock, flags);
if (!minor) {
return ERR_PTR(-ENODEV);
} else if (drm_device_is_unplugged(minor->dev)) {
drm_dev_unref(minor->dev);
return ERR_PTR(-ENODEV);
}
return minor;
}
/**
* drm_minor_release - Release DRM minor
* @minor: Pointer to DRM minor object
*
* Release a minor that was previously acquired via drm_minor_acquire().
*/
void drm_minor_release(struct drm_minor *minor)
{
drm_dev_unref(minor->dev);
}
/**
* DOC: driver instance overview
*
* A device instance for a drm driver is represented by struct &drm_device. This
* is allocated with 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 intial output configuration plus obviously
* initialize all the corresponding hardware bits. An important part of this is
* also calling drm_dev_set_unique() to set the userspace-visible unique name of
* this device instance. 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 initalizing device instances using
* bus-specific helpers and the ->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_unref().
*
* Note that the lifetime rules for &drm_device instance has still a lot of
* historical baggage. Hence use the reference counting provided by
* drm_dev_ref() and drm_dev_unref() only carefully.
*
* Also note that embedding of &drm_device is currently not (yet) supported (but
* it would be easy to add). Drivers can store driver-private data in the
* dev_priv field of &drm_device.
*/
/**
* 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_unref() 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_unref(dev);
}
EXPORT_SYMBOL(drm_put_dev);
void drm_unplug_dev(struct drm_device *dev)
{
/* for a USB device */
drm_minor_unregister(dev, DRM_MINOR_LEGACY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
drm_minor_unregister(dev, DRM_MINOR_CONTROL);
mutex_lock(&drm_global_mutex);
drm_device_set_unplugged(dev);
if (dev->open_count == 0) {
drm_put_dev(dev);
}
mutex_unlock(&drm_global_mutex);
}
EXPORT_SYMBOL(drm_unplug_dev);
/*
* 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 const struct dentry_operations drm_fs_dops = {
.d_dname = simple_dname,
};
static const struct super_operations drm_fs_sops = {
.statfs = simple_statfs,
};
static struct dentry *drm_fs_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data)
{
return mount_pseudo(fs_type,
"drm:",
&drm_fs_sops,
&drm_fs_dops,
0x010203ff);
}
static struct file_system_type drm_fs_type = {
.name = "drm",
.owner = THIS_MODULE,
.mount = drm_fs_mount,
.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);
}
}
/**
* drm_dev_alloc - Allocate new DRM device
* @driver: DRM driver to allocate device for
* @parent: Parent device object
*
* Allocate and initialize a new DRM device. No device registration is done.
* Call drm_dev_register() to advertice the device to user space and register it
* with other core subsystems. This should be done last in the device
* initialization sequence to make sure userspace can't access an inconsistent
* state.
*
* The initial ref-count of the object is 1. Use drm_dev_ref() and
* drm_dev_unref() to take and drop further ref-counts.
*
* Note that for purely virtual devices @parent can be NULL.
*
* RETURNS:
* Pointer to new DRM device, or NULL if out of memory.
*/
struct drm_device *drm_dev_alloc(struct drm_driver *driver,
struct device *parent)
{
struct drm_device *dev;
int ret;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return NULL;
kref_init(&dev->ref);
dev->dev = parent;
dev->driver = driver;
INIT_LIST_HEAD(&dev->filelist);
INIT_LIST_HEAD(&dev->ctxlist);
INIT_LIST_HEAD(&dev->vmalist);
INIT_LIST_HEAD(&dev->maplist);
INIT_LIST_HEAD(&dev->vblank_event_list);
spin_lock_init(&dev->buf_lock);
spin_lock_init(&dev->event_lock);
mutex_init(&dev->struct_mutex);
mutex_init(&dev->ctxlist_mutex);
mutex_init(&dev->master_mutex);
dev->anon_inode = drm_fs_inode_new();
if (IS_ERR(dev->anon_inode)) {
ret = PTR_ERR(dev->anon_inode);
DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
goto err_free;
}
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
if (ret)
goto err_minors;
WARN_ON(driver->suspend || driver->resume);
}
if (drm_core_check_feature(dev, DRIVER_RENDER)) {
ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
if (ret)
goto err_minors;
}
ret = drm_minor_alloc(dev, DRM_MINOR_LEGACY);
if (ret)
goto err_minors;
if (drm_ht_create(&dev->map_hash, 12))
goto err_minors;
drm_legacy_ctxbitmap_init(dev);
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_ctxbitmap;
}
}
return dev;
err_ctxbitmap:
drm_legacy_ctxbitmap_cleanup(dev);
drm_ht_remove(&dev->map_hash);
err_minors:
drm_minor_free(dev, DRM_MINOR_LEGACY);
drm_minor_free(dev, DRM_MINOR_RENDER);
drm_minor_free(dev, DRM_MINOR_CONTROL);
drm_fs_inode_free(dev->anon_inode);
err_free:
mutex_destroy(&dev->master_mutex);
kfree(dev);
return NULL;
}
EXPORT_SYMBOL(drm_dev_alloc);
static void drm_dev_release(struct kref *ref)
{
struct drm_device *dev = container_of(ref, struct drm_device, ref);
if (drm_core_check_feature(dev, DRIVER_GEM))
drm_gem_destroy(dev);
drm_legacy_ctxbitmap_cleanup(dev);
drm_ht_remove(&dev->map_hash);
drm_fs_inode_free(dev->anon_inode);
drm_minor_free(dev, DRM_MINOR_LEGACY);
drm_minor_free(dev, DRM_MINOR_RENDER);
drm_minor_free(dev, DRM_MINOR_CONTROL);
mutex_destroy(&dev->master_mutex);
kfree(dev->unique);
kfree(dev);
}
/**
* drm_dev_ref - 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_unref() 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_ref(struct drm_device *dev)
{
if (dev)
kref_get(&dev->ref);
}
EXPORT_SYMBOL(drm_dev_ref);
/**
* drm_dev_unref - 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_unref(struct drm_device *dev)
{
if (dev)
kref_put(&dev->ref, drm_dev_release);
}
EXPORT_SYMBOL(drm_dev_unref);
/**
* 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 allocated via drm_dev_alloc()
* previously.
*
* Never call this twice on any device!
*
* NOTE: To ensure backward compatibility with existing drivers method this
* function calls the ->load() method after registering the device nodes,
* creating race conditions. Usage of the ->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)
{
int ret;
mutex_lock(&drm_global_mutex);
ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
if (ret)
goto err_minors;
ret = drm_minor_register(dev, DRM_MINOR_RENDER);
if (ret)
goto err_minors;
ret = drm_minor_register(dev, DRM_MINOR_LEGACY);
if (ret)
goto err_minors;
if (dev->driver->load) {
ret = dev->driver->load(dev, flags);
if (ret)
goto err_minors;
}
ret = 0;
goto out_unlock;
err_minors:
drm_minor_unregister(dev, DRM_MINOR_LEGACY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
drm_minor_unregister(dev, DRM_MINOR_CONTROL);
out_unlock:
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_unref() to drop their final reference.
*
* 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)
{
struct drm_map_list *r_list, *list_temp;
drm_lastclose(dev);
if (dev->driver->unload)
dev->driver->unload(dev);
if (dev->agp)
drm_pci_agp_destroy(dev);
drm_vblank_cleanup(dev);
list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
drm_legacy_rmmap(dev, r_list->map);
drm_minor_unregister(dev, DRM_MINOR_LEGACY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
drm_minor_unregister(dev, DRM_MINOR_CONTROL);
}
EXPORT_SYMBOL(drm_dev_unregister);
/**
* drm_dev_set_unique - Set the unique name of a DRM device
* @dev: device of which to set the unique name
* @fmt: format string for unique name
*
* Sets the unique name of a DRM device using the specified format string and
* a variable list of arguments. Drivers can use this at driver probe time if
* the unique name of the devices they drive is static.
*
* Return: 0 on success or a negative error code on failure.
*/
int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
{
va_list ap;
kfree(dev->unique);
va_start(ap, fmt);
dev->unique = kvasprintf(GFP_KERNEL, fmt, ap);
va_end(ap);
return dev->unique ? 0 : -ENOMEM;
}
EXPORT_SYMBOL(drm_dev_set_unique);
/*
* 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");
mutex_lock(&drm_global_mutex);
minor = drm_minor_acquire(iminor(inode));
if (IS_ERR(minor)) {
err = PTR_ERR(minor);
goto out_unlock;
}
new_fops = fops_get(minor->dev->driver->fops);
if (!new_fops) {
err = -ENODEV;
goto out_release;
}
replace_fops(filp, new_fops);
if (filp->f_op->open)
err = filp->f_op->open(inode, filp);
else
err = 0;
out_release:
drm_minor_release(minor);
out_unlock:
mutex_unlock(&drm_global_mutex);
return err;
}
static const struct file_operations drm_stub_fops = {
.owner = THIS_MODULE,
.open = drm_stub_open,
.llseek = noop_llseek,
};
static int __init drm_core_init(void)
{
int ret = -ENOMEM;
drm_global_init();
drm_connector_ida_init();
idr_init(&drm_minors_idr);
if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
goto err_p1;
ret = drm_sysfs_init();
if (ret < 0) {
printk(KERN_ERR "DRM: Error creating drm class.\n");
goto err_p2;
}
drm_debugfs_root = debugfs_create_dir("dri", NULL);
if (!drm_debugfs_root) {
DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
ret = -1;
goto err_p3;
}
DRM_INFO("Initialized %s %d.%d.%d %s\n",
CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
return 0;
err_p3:
drm_sysfs_destroy();
err_p2:
unregister_chrdev(DRM_MAJOR, "drm");
idr_destroy(&drm_minors_idr);
err_p1:
return ret;
}
static void __exit drm_core_exit(void)
{
debugfs_remove(drm_debugfs_root);
drm_sysfs_destroy();
unregister_chrdev(DRM_MAJOR, "drm");
drm_connector_ida_destroy();
idr_destroy(&drm_minors_idr);
}
module_init(drm_core_init);
module_exit(drm_core_exit);