linux/drivers/gpu/drm/drm_ioctl.c
Ilija Hadzic 09b4ea47d1 drm: make DRM_UNLOCKED ioctls with their own mutex
drm_getclient, drm_getstats and drm_getmap (with a few minor
adjustments) do not need global mutex, so fix that and
make the said ioctls DRM_UNLOCKED. Details:

  drm_getclient: the only thing that should be protected here
  is dev->filelist and that is already protected everywhere with
  dev->struct_mutex.

  drm_getstats: there is no need for any mutex here because the
  loop runs through quasi-static (set at load time only)
  data, and the actual count access is done with atomic_read()

  drm_getmap already uses dev->struct_mutex to protect
  dev->maplist, which also used to protect the same structure
  everywhere else except at three places:
  * drm_getsarea, which doesn't grab *any* mutex before
    touching dev->maplist (so no drm_global_mutex doesn't help
    here either; different issue for a different patch).
    However, drivers seem to call it only at
    initialization time so it probably doesn't matter
  * drm_master_destroy, which is called from drm_master_put,
    which in turn is protected with dev->struct_mutex
    everywhere else in drm module, so we are good here too.
  * drm_getsareactx, which releases the dev->struct_mutex
    too early, but this patch includes the fix for that.

v2: * incorporate comments received from Daniel Vetter
    * include the (long) explanation above to make it clear what
      we are doing (and why), also at Daniel Vetter's request
    * tighten up mutex grab/release locations to only
      encompass real critical sections, rather than some
      random code around them

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-01-05 14:43:02 +00:00

348 lines
8.4 KiB
C

/**
* \file drm_ioctl.c
* IOCTL processing for DRM
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
* \author Gareth Hughes <gareth@valinux.com>
*/
/*
* Created: Fri Jan 8 09:01:26 1999 by faith@valinux.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 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
* VA LINUX SYSTEMS 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 "drmP.h"
#include "drm_core.h"
#include "linux/pci.h"
/**
* Get the bus id.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_unique structure.
* \return zero on success or a negative number on failure.
*
* Copies the bus id from drm_device::unique into user space.
*/
int drm_getunique(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_unique *u = data;
struct drm_master *master = file_priv->master;
if (u->unique_len >= master->unique_len) {
if (copy_to_user(u->unique, master->unique, master->unique_len))
return -EFAULT;
}
u->unique_len = master->unique_len;
return 0;
}
static void
drm_unset_busid(struct drm_device *dev,
struct drm_master *master)
{
kfree(dev->devname);
dev->devname = NULL;
kfree(master->unique);
master->unique = NULL;
master->unique_len = 0;
master->unique_size = 0;
}
/**
* Set the bus id.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_unique structure.
* \return zero on success or a negative number on failure.
*
* Copies the bus id from userspace into drm_device::unique, and verifies that
* it matches the device this DRM is attached to (EINVAL otherwise). Deprecated
* in interface version 1.1 and will return EBUSY when setversion has requested
* version 1.1 or greater.
*/
int drm_setunique(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_unique *u = data;
struct drm_master *master = file_priv->master;
int ret;
if (master->unique_len || master->unique)
return -EBUSY;
if (!u->unique_len || u->unique_len > 1024)
return -EINVAL;
if (!dev->driver->bus->set_unique)
return -EINVAL;
ret = dev->driver->bus->set_unique(dev, master, u);
if (ret)
goto err;
return 0;
err:
drm_unset_busid(dev, master);
return ret;
}
static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
{
struct drm_master *master = file_priv->master;
int ret;
if (master->unique != NULL)
drm_unset_busid(dev, master);
ret = dev->driver->bus->set_busid(dev, master);
if (ret)
goto err;
return 0;
err:
drm_unset_busid(dev, master);
return ret;
}
/**
* Get a mapping information.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_map structure.
*
* \return zero on success or a negative number on failure.
*
* Searches for the mapping with the specified offset and copies its information
* into userspace
*/
int drm_getmap(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_map *map = data;
struct drm_map_list *r_list = NULL;
struct list_head *list;
int idx;
int i;
idx = map->offset;
if (idx < 0)
return -EINVAL;
i = 0;
mutex_lock(&dev->struct_mutex);
list_for_each(list, &dev->maplist) {
if (i == idx) {
r_list = list_entry(list, struct drm_map_list, head);
break;
}
i++;
}
if (!r_list || !r_list->map) {
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
map->offset = r_list->map->offset;
map->size = r_list->map->size;
map->type = r_list->map->type;
map->flags = r_list->map->flags;
map->handle = (void *)(unsigned long) r_list->user_token;
map->mtrr = r_list->map->mtrr;
mutex_unlock(&dev->struct_mutex);
return 0;
}
/**
* Get client information.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_client structure.
*
* \return zero on success or a negative number on failure.
*
* Searches for the client with the specified index and copies its information
* into userspace
*/
int drm_getclient(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_client *client = data;
struct drm_file *pt;
int idx;
int i;
idx = client->idx;
i = 0;
mutex_lock(&dev->struct_mutex);
list_for_each_entry(pt, &dev->filelist, lhead) {
if (i++ >= idx) {
client->auth = pt->authenticated;
client->pid = pt->pid;
client->uid = pt->uid;
client->magic = pt->magic;
client->iocs = pt->ioctl_count;
mutex_unlock(&dev->struct_mutex);
return 0;
}
}
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}
/**
* Get statistics information.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_stats structure.
*
* \return zero on success or a negative number on failure.
*/
int drm_getstats(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_stats *stats = data;
int i;
memset(stats, 0, sizeof(*stats));
for (i = 0; i < dev->counters; i++) {
if (dev->types[i] == _DRM_STAT_LOCK)
stats->data[i].value =
(file_priv->master->lock.hw_lock ? file_priv->master->lock.hw_lock->lock : 0);
else
stats->data[i].value = atomic_read(&dev->counts[i]);
stats->data[i].type = dev->types[i];
}
stats->count = dev->counters;
return 0;
}
/**
* Get device/driver capabilities
*/
int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
struct drm_get_cap *req = data;
req->value = 0;
switch (req->capability) {
case DRM_CAP_DUMB_BUFFER:
if (dev->driver->dumb_create)
req->value = 1;
break;
case DRM_CAP_VBLANK_HIGH_CRTC:
req->value = 1;
break;
default:
return -EINVAL;
}
return 0;
}
/**
* Setversion ioctl.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_lock structure.
* \return zero on success or negative number on failure.
*
* Sets the requested interface version
*/
int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
struct drm_set_version *sv = data;
int if_version, retcode = 0;
if (sv->drm_di_major != -1) {
if (sv->drm_di_major != DRM_IF_MAJOR ||
sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
retcode = -EINVAL;
goto done;
}
if_version = DRM_IF_VERSION(sv->drm_di_major,
sv->drm_di_minor);
dev->if_version = max(if_version, dev->if_version);
if (sv->drm_di_minor >= 1) {
/*
* Version 1.1 includes tying of DRM to specific device
* Version 1.4 has proper PCI domain support
*/
retcode = drm_set_busid(dev, file_priv);
if (retcode)
goto done;
}
}
if (sv->drm_dd_major != -1) {
if (sv->drm_dd_major != dev->driver->major ||
sv->drm_dd_minor < 0 || sv->drm_dd_minor >
dev->driver->minor) {
retcode = -EINVAL;
goto done;
}
if (dev->driver->set_version)
dev->driver->set_version(dev, sv);
}
done:
sv->drm_di_major = DRM_IF_MAJOR;
sv->drm_di_minor = DRM_IF_MINOR;
sv->drm_dd_major = dev->driver->major;
sv->drm_dd_minor = dev->driver->minor;
return retcode;
}
/** No-op ioctl. */
int drm_noop(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
DRM_DEBUG("\n");
return 0;
}