alistair23-linux/drivers/gpu/drm/drm_stub.c
David Herrmann 1793126fce drm: implement experimental render nodes
Render nodes provide an API for userspace to use non-privileged GPU
commands without any running DRM-Master. It is useful for offscreen
rendering, GPGPU clients, and normal render clients which do not perform
modesetting.

Compared to legacy clients, render clients no longer need any
authentication to perform client ioctls. Instead, user-space controls
render/client access to GPUs via filesystem access-modes on the
render-node. Once a render-node was opened, a client has full access to
the client/render operations on the GPU. However, no modesetting or ioctls
that affect global state are allowed on render nodes.

To prevent privilege-escalation, drivers must explicitly state that they
support render nodes. They must mark their render-only ioctls as
DRM_RENDER_ALLOW so render clients can use them. Furthermore, they must
support clients without any attached master.

If filesystem access-modes are not enough for fine-grained access control
to render nodes (very unlikely, considering the versaitlity of FS-ACLs),
you may still fall-back to fd-passing from server to client (which allows
arbitrary access-control). However, note that revoking access is
currently impossible and unlikely to get implemented.

Note: Render clients no longer have any associated DRM-Master as they are
supposed to be independent of any server state. DRM core highly depends on
file_priv->master to be non-NULL for modesetting/ctx/etc. commands.
Therefore, drivers must be very careful to not require DRM-Master if they
support DRIVER_RENDER.

So far render-nodes are protected by "drm_rnodes". As long as this
module-parameter is not set to 1, a driver will not create render nodes.
This allows us to experiment with the API a bit before we stabilize it.

v2: drop insecure GEM_FLINK to force use of dmabuf

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-08-30 08:43:57 +10:00

487 lines
11 KiB
C

/**
* \file drm_stub.h
* Stub support
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
*/
/*
* Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
*
* Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
* All Rights Reserved.
*
* 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/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <drm/drmP.h>
#include <drm/drm_core.h>
unsigned int drm_debug = 0; /* 1 to enable debug output */
EXPORT_SYMBOL(drm_debug);
unsigned int drm_rnodes = 0; /* 1 to enable experimental render nodes API */
EXPORT_SYMBOL(drm_rnodes);
unsigned int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
EXPORT_SYMBOL(drm_vblank_offdelay);
unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
EXPORT_SYMBOL(drm_timestamp_precision);
/*
* Default to use monotonic timestamps for wait-for-vblank and page-flip
* complete events.
*/
unsigned int drm_timestamp_monotonic = 1;
MODULE_AUTHOR(CORE_AUTHOR);
MODULE_DESCRIPTION(CORE_DESC);
MODULE_LICENSE("GPL and additional rights");
MODULE_PARM_DESC(debug, "Enable debug output");
MODULE_PARM_DESC(rnodes, "Enable experimental render nodes API");
MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs]");
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);
module_param_named(rnodes, drm_rnodes, int, 0600);
module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
struct idr drm_minors_idr;
struct class *drm_class;
struct dentry *drm_debugfs_root;
int drm_err(const char *func, const char *format, ...)
{
struct va_format vaf;
va_list args;
int r;
va_start(args, format);
vaf.fmt = format;
vaf.va = &args;
r = printk(KERN_ERR "[" DRM_NAME ":%s] *ERROR* %pV", func, &vaf);
va_end(args);
return r;
}
EXPORT_SYMBOL(drm_err);
void drm_ut_debug_printk(unsigned int request_level,
const char *prefix,
const char *function_name,
const char *format, ...)
{
va_list args;
if (drm_debug & request_level) {
if (function_name)
printk(KERN_DEBUG "[%s:%s], ", prefix, function_name);
va_start(args, format);
vprintk(format, args);
va_end(args);
}
}
EXPORT_SYMBOL(drm_ut_debug_printk);
static int drm_minor_get_id(struct drm_device *dev, int type)
{
int ret;
int base = 0, limit = 63;
if (type == DRM_MINOR_CONTROL) {
base += 64;
limit = base + 63;
} else if (type == DRM_MINOR_RENDER) {
base += 128;
limit = base + 63;
}
mutex_lock(&dev->struct_mutex);
ret = idr_alloc(&drm_minors_idr, NULL, base, limit, GFP_KERNEL);
mutex_unlock(&dev->struct_mutex);
return ret == -ENOSPC ? -EINVAL : ret;
}
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);
drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER);
INIT_LIST_HEAD(&master->magicfree);
master->minor = minor;
list_add_tail(&master->head, &minor->master_list);
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_magic_entry *pt, *next;
struct drm_device *dev = master->minor->dev;
struct drm_map_list *r_list, *list_temp;
list_del(&master->head);
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_rmmap_locked(dev, r_list->map);
r_list = NULL;
}
}
if (master->unique) {
kfree(master->unique);
master->unique = NULL;
master->unique_len = 0;
}
kfree(dev->devname);
dev->devname = NULL;
list_for_each_entry_safe(pt, next, &master->magicfree, head) {
list_del(&pt->head);
drm_ht_remove_item(&master->magiclist, &pt->hash_item);
kfree(pt);
}
drm_ht_remove(&master->magiclist);
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;
if (file_priv->is_master)
return 0;
if (file_priv->minor->master && file_priv->minor->master != file_priv->master)
return -EINVAL;
if (!file_priv->master)
return -EINVAL;
if (file_priv->minor->master)
return -EINVAL;
mutex_lock(&dev->struct_mutex);
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);
}
}
mutex_unlock(&dev->struct_mutex);
return ret;
}
int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
if (!file_priv->is_master)
return -EINVAL;
if (!file_priv->minor->master)
return -EINVAL;
mutex_lock(&dev->struct_mutex);
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;
mutex_unlock(&dev->struct_mutex);
return 0;
}
int drm_fill_in_dev(struct drm_device *dev,
const struct pci_device_id *ent,
struct drm_driver *driver)
{
int retcode;
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->count_lock);
spin_lock_init(&dev->event_lock);
mutex_init(&dev->struct_mutex);
mutex_init(&dev->ctxlist_mutex);
if (drm_ht_create(&dev->map_hash, 12)) {
return -ENOMEM;
}
/* the DRM has 6 basic counters */
dev->counters = 6;
dev->types[0] = _DRM_STAT_LOCK;
dev->types[1] = _DRM_STAT_OPENS;
dev->types[2] = _DRM_STAT_CLOSES;
dev->types[3] = _DRM_STAT_IOCTLS;
dev->types[4] = _DRM_STAT_LOCKS;
dev->types[5] = _DRM_STAT_UNLOCKS;
dev->driver = driver;
if (dev->driver->bus->agp_init) {
retcode = dev->driver->bus->agp_init(dev);
if (retcode)
goto error_out_unreg;
}
drm_legacy_ctxbitmap_init(dev);
if (driver->driver_features & DRIVER_GEM) {
retcode = drm_gem_init(dev);
if (retcode) {
DRM_ERROR("Cannot initialize graphics execution "
"manager (GEM)\n");
goto error_out_unreg;
}
}
return 0;
error_out_unreg:
drm_lastclose(dev);
return retcode;
}
EXPORT_SYMBOL(drm_fill_in_dev);
/**
* Get a secondary minor number.
*
* \param dev device data structure
* \param sec-minor structure to hold the assigned minor
* \return negative number on failure.
*
* Search an empty entry and initialize it to the given parameters. This
* routines assigns minor numbers to secondary heads of multi-headed cards
*/
int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int type)
{
struct drm_minor *new_minor;
int ret;
int minor_id;
DRM_DEBUG("\n");
minor_id = drm_minor_get_id(dev, type);
if (minor_id < 0)
return minor_id;
new_minor = kzalloc(sizeof(struct drm_minor), GFP_KERNEL);
if (!new_minor) {
ret = -ENOMEM;
goto err_idr;
}
new_minor->type = type;
new_minor->device = MKDEV(DRM_MAJOR, minor_id);
new_minor->dev = dev;
new_minor->index = minor_id;
INIT_LIST_HEAD(&new_minor->master_list);
idr_replace(&drm_minors_idr, new_minor, minor_id);
#if defined(CONFIG_DEBUG_FS)
ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);
if (ret) {
DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
goto err_mem;
}
#endif
ret = drm_sysfs_device_add(new_minor);
if (ret) {
printk(KERN_ERR
"DRM: Error sysfs_device_add.\n");
goto err_debugfs;
}
*minor = new_minor;
DRM_DEBUG("new minor assigned %d\n", minor_id);
return 0;
err_debugfs:
#if defined(CONFIG_DEBUG_FS)
drm_debugfs_cleanup(new_minor);
err_mem:
#endif
kfree(new_minor);
err_idr:
idr_remove(&drm_minors_idr, minor_id);
*minor = NULL;
return ret;
}
EXPORT_SYMBOL(drm_get_minor);
/**
* Put a secondary minor number.
*
* \param sec_minor - structure to be released
* \return always zero
*/
int drm_put_minor(struct drm_minor **minor_p)
{
struct drm_minor *minor = *minor_p;
DRM_DEBUG("release secondary minor %d\n", minor->index);
#if defined(CONFIG_DEBUG_FS)
drm_debugfs_cleanup(minor);
#endif
drm_sysfs_device_remove(minor);
idr_remove(&drm_minors_idr, minor->index);
kfree(minor);
*minor_p = NULL;
return 0;
}
EXPORT_SYMBOL(drm_put_minor);
static void drm_unplug_minor(struct drm_minor *minor)
{
drm_sysfs_device_remove(minor);
}
/**
* Called via drm_exit() at module unload time or when pci device is
* unplugged.
*
* Cleans up all DRM device, calling drm_lastclose().
*
*/
void drm_put_dev(struct drm_device *dev)
{
struct drm_driver *driver;
struct drm_map_list *r_list, *list_temp;
DRM_DEBUG("\n");
if (!dev) {
DRM_ERROR("cleanup called no dev\n");
return;
}
driver = dev->driver;
drm_lastclose(dev);
if (dev->driver->unload)
dev->driver->unload(dev);
if (dev->driver->bus->agp_destroy)
dev->driver->bus->agp_destroy(dev);
drm_vblank_cleanup(dev);
list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head)
drm_rmmap(dev, r_list->map);
drm_ht_remove(&dev->map_hash);
drm_legacy_ctxbitmap_cleanup(dev);
if (drm_core_check_feature(dev, DRIVER_MODESET))
drm_put_minor(&dev->control);
if (dev->render)
drm_put_minor(&dev->render);
if (driver->driver_features & DRIVER_GEM)
drm_gem_destroy(dev);
drm_put_minor(&dev->primary);
list_del(&dev->driver_item);
kfree(dev->devname);
kfree(dev);
}
EXPORT_SYMBOL(drm_put_dev);
void drm_unplug_dev(struct drm_device *dev)
{
/* for a USB device */
if (drm_core_check_feature(dev, DRIVER_MODESET))
drm_unplug_minor(dev->control);
if (dev->render)
drm_unplug_minor(dev->render);
drm_unplug_minor(dev->primary);
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);