2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-25 05:34:00 +08:00
linux-next/drivers/gpu/drm/msm/msm_gem_shrinker.c
Archit Taneja 16976085a1 drm/msm: Fix error handling crashes seen when VRAM allocation fails
If VRAM allocation fails, the error handling path crashes in
msm_drm_uninit(). The following changes are made to fix this:

msm_gem_shrinker_cleanup() is fixed to unregister the shrinker only
if it was init-ed in the first place.

Before calling kms->funcs->destroy(), we check if kms->funcs is also
non-NULL. This is needed for MDP5, since during msm_drm_int(), priv->kms
becomes non-NULL early, but msm_kms_init() is called on it only later
in mdp5_kms_init().

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
2016-11-04 11:51:37 -04:00

172 lines
4.3 KiB
C

/*
* Copyright (C) 2016 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "msm_drv.h"
#include "msm_gem.h"
static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
{
if (!mutex_is_locked(mutex))
return false;
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_MUTEXES)
return mutex->owner == task;
#else
/* Since UP may be pre-empted, we cannot assume that we own the lock */
return false;
#endif
}
static bool msm_gem_shrinker_lock(struct drm_device *dev, bool *unlock)
{
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
return false;
*unlock = false;
} else {
*unlock = true;
}
return true;
}
static unsigned long
msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
{
struct msm_drm_private *priv =
container_of(shrinker, struct msm_drm_private, shrinker);
struct drm_device *dev = priv->dev;
struct msm_gem_object *msm_obj;
unsigned long count = 0;
bool unlock;
if (!msm_gem_shrinker_lock(dev, &unlock))
return 0;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (is_purgeable(msm_obj))
count += msm_obj->base.size >> PAGE_SHIFT;
}
if (unlock)
mutex_unlock(&dev->struct_mutex);
return count;
}
static unsigned long
msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
{
struct msm_drm_private *priv =
container_of(shrinker, struct msm_drm_private, shrinker);
struct drm_device *dev = priv->dev;
struct msm_gem_object *msm_obj;
unsigned long freed = 0;
bool unlock;
if (!msm_gem_shrinker_lock(dev, &unlock))
return SHRINK_STOP;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (freed >= sc->nr_to_scan)
break;
if (is_purgeable(msm_obj)) {
msm_gem_purge(&msm_obj->base);
freed += msm_obj->base.size >> PAGE_SHIFT;
}
}
if (unlock)
mutex_unlock(&dev->struct_mutex);
if (freed > 0)
pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT);
return freed;
}
static int
msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
{
struct msm_drm_private *priv =
container_of(nb, struct msm_drm_private, vmap_notifier);
struct drm_device *dev = priv->dev;
struct msm_gem_object *msm_obj;
unsigned unmapped = 0;
bool unlock;
if (!msm_gem_shrinker_lock(dev, &unlock))
return NOTIFY_DONE;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (is_vunmapable(msm_obj)) {
msm_gem_vunmap(&msm_obj->base);
/* since we don't know any better, lets bail after a few
* and if necessary the shrinker will be invoked again.
* Seems better than unmapping *everything*
*/
if (++unmapped >= 15)
break;
}
}
if (unlock)
mutex_unlock(&dev->struct_mutex);
*(unsigned long *)ptr += unmapped;
if (unmapped > 0)
pr_info_ratelimited("Purging %u vmaps\n", unmapped);
return NOTIFY_DONE;
}
/**
* msm_gem_shrinker_init - Initialize msm shrinker
* @dev_priv: msm device
*
* This function registers and sets up the msm shrinker.
*/
void msm_gem_shrinker_init(struct drm_device *dev)
{
struct msm_drm_private *priv = dev->dev_private;
priv->shrinker.count_objects = msm_gem_shrinker_count;
priv->shrinker.scan_objects = msm_gem_shrinker_scan;
priv->shrinker.seeks = DEFAULT_SEEKS;
WARN_ON(register_shrinker(&priv->shrinker));
priv->vmap_notifier.notifier_call = msm_gem_shrinker_vmap;
WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier));
}
/**
* msm_gem_shrinker_cleanup - Clean up msm shrinker
* @dev_priv: msm device
*
* This function unregisters the msm shrinker.
*/
void msm_gem_shrinker_cleanup(struct drm_device *dev)
{
struct msm_drm_private *priv = dev->dev_private;
if (priv->shrinker.nr_deferred) {
WARN_ON(unregister_vmap_purge_notifier(&priv->vmap_notifier));
unregister_shrinker(&priv->shrinker);
}
}