linux/drivers/gpu/drm/drm_drv.c

939 lines
25 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"
/*
* drm_debug: Enable debug output.
* Bitmask of DRM_UT_x. See include/drm/drmP.h for details.
*/
unsigned int drm_debug = 0;
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, where each bit enables a debug category.\n"
"\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
"\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
"\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
"\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
"\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
"\t\tBit 5 (0x20) will enable VBL messages (vblank code)");
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;
if (dev->driver->master_destroy)
dev->driver->master_destroy(dev, master);
drm_legacy_master_rmmaps(dev, master);
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->filelist_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;
}
}
if (parent) {
ret = drm_dev_set_unique(dev, dev_name(parent));
if (ret)
goto err_setunique;
}
return dev;
err_setunique:
if (drm_core_check_feature(dev, DRIVER_GEM))
drm_gem_destroy(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. Right after drm_dev_register() the driver should call
* drm_connector_register_all() to register all connectors in sysfs. This is
* a separate call for backward compatibility with drivers still using
* the deprecated ->load() callback, where connectors are registered from within
* the ->load() callback.
*
* 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
* @name: unique name
*
* Sets the unique name of a DRM device using the specified string. 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 *name)
{
kfree(dev->unique);
dev->unique = kstrdup(name, GFP_KERNEL);
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);