[04/14] drm/msm: Add priv->mm_lock to protect active/inactive lists
diff mbox series

Message ID 20201004192152.3298573-5-robdclark@gmail.com
State New, archived
Headers show
Series
  • drm/msm: de-struct_mutex-ification
Related show

Commit Message

Rob Clark Oct. 4, 2020, 7:21 p.m. UTC
From: Rob Clark <robdclark@chromium.org>

Rather than relying on the big dev->struct_mutex hammer, introduce a
more specific lock for protecting the bo lists.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/msm_debugfs.c      |  7 +++++++
 drivers/gpu/drm/msm/msm_drv.c          |  1 +
 drivers/gpu/drm/msm/msm_drv.h          | 13 +++++++++++-
 drivers/gpu/drm/msm/msm_gem.c          | 28 +++++++++++++++-----------
 drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++++++++++
 drivers/gpu/drm/msm/msm_gpu.h          |  5 ++++-
 6 files changed, 52 insertions(+), 14 deletions(-)

Comments

Daniel Vetter Oct. 4, 2020, 10:15 p.m. UTC | #1
On Sun, Oct 4, 2020 at 9:21 PM Rob Clark <robdclark@gmail.com> wrote:
>
> From: Rob Clark <robdclark@chromium.org>
>
> Rather than relying on the big dev->struct_mutex hammer, introduce a
> more specific lock for protecting the bo lists.
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>  drivers/gpu/drm/msm/msm_debugfs.c      |  7 +++++++
>  drivers/gpu/drm/msm/msm_drv.c          |  1 +
>  drivers/gpu/drm/msm/msm_drv.h          | 13 +++++++++++-
>  drivers/gpu/drm/msm/msm_gem.c          | 28 +++++++++++++++-----------
>  drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++++++++++
>  drivers/gpu/drm/msm/msm_gpu.h          |  5 ++++-
>  6 files changed, 52 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
> index ee2e270f464c..64afbed89821 100644
> --- a/drivers/gpu/drm/msm/msm_debugfs.c
> +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> @@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
>  {
>         struct msm_drm_private *priv = dev->dev_private;
>         struct msm_gpu *gpu = priv->gpu;
> +       int ret;
> +
> +       ret = mutex_lock_interruptible(&priv->mm_lock);
> +       if (ret)
> +               return ret;
>
>         if (gpu) {
>                 seq_printf(m, "Active Objects (%s):\n", gpu->name);
> @@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
>         seq_printf(m, "Inactive Objects:\n");
>         msm_gem_describe_objects(&priv->inactive_list, m);
>
> +       mutex_unlock(&priv->mm_lock);
> +
>         return 0;
>  }
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 49685571dc0e..dc6efc089285 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>         init_llist_head(&priv->free_list);
>
>         INIT_LIST_HEAD(&priv->inactive_list);
> +       mutex_init(&priv->mm_lock);

I highly recommend you drop a

fs_reclaim_acquire(GFP_KERNEL);
might_lock(&priv->mm_lock);
fs_reclaim_release(GFP_KERNEL);

in here to teach lockdep about your ordering against the shrinker.
Gives you full testing every boot, even if your shrinker never gets
called.
-Daniel

>
>         drm_mode_config_init(ddev);
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index b9dd8f8f4887..50978e5db376 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -174,8 +174,19 @@ struct msm_drm_private {
>         struct msm_rd_state *hangrd;   /* debugfs to dump hanging submits */
>         struct msm_perf_state *perf;
>
> -       /* list of GEM objects: */
> +       /*
> +        * List of inactive GEM objects.  Every bo is either in the inactive_list
> +        * or gpu->active_list (for the gpu it is active on[1])
> +        *
> +        * These lists are protected by mm_lock.  If struct_mutex is involved, it
> +        * should be aquired prior to mm_lock.  One should *not* hold mm_lock in
> +        * get_pages()/vmap()/etc paths, as they can trigger the shrinker.
> +        *
> +        * [1] if someone ever added support for the old 2d cores, there could be
> +        *     more than one gpu object
> +        */
>         struct list_head inactive_list;
> +       struct mutex mm_lock;
>
>         /* worker for delayed free of objects: */
>         struct work_struct free_work;
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index a870b3ad129d..b04ed8b52f9d 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -746,13 +746,17 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
>  void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
>  {
>         struct msm_gem_object *msm_obj = to_msm_bo(obj);
> -       WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> +       struct msm_drm_private *priv = obj->dev->dev_private;
> +
> +       might_sleep();
>         WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
>
>         if (!atomic_fetch_inc(&msm_obj->active_count)) {
> +               mutex_lock(&priv->mm_lock);
>                 msm_obj->gpu = gpu;
>                 list_del_init(&msm_obj->mm_list);
>                 list_add_tail(&msm_obj->mm_list, &gpu->active_list);
> +               mutex_unlock(&priv->mm_lock);
>         }
>  }
>
> @@ -761,12 +765,14 @@ void msm_gem_active_put(struct drm_gem_object *obj)
>         struct msm_gem_object *msm_obj = to_msm_bo(obj);
>         struct msm_drm_private *priv = obj->dev->dev_private;
>
> -       WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> +       might_sleep();
>
>         if (!atomic_dec_return(&msm_obj->active_count)) {
> +               mutex_lock(&priv->mm_lock);
>                 msm_obj->gpu = NULL;
>                 list_del_init(&msm_obj->mm_list);
>                 list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> +               mutex_unlock(&priv->mm_lock);
>         }
>  }
>
> @@ -921,13 +927,16 @@ static void free_object(struct msm_gem_object *msm_obj)
>  {
>         struct drm_gem_object *obj = &msm_obj->base;
>         struct drm_device *dev = obj->dev;
> +       struct msm_drm_private *priv = dev->dev_private;
>
>         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
>         /* object should not be on active list: */
>         WARN_ON(is_active(msm_obj));
>
> +       mutex_lock(&priv->mm_lock);
>         list_del(&msm_obj->mm_list);
> +       mutex_unlock(&priv->mm_lock);
>
>         mutex_lock(&msm_obj->lock);
>
> @@ -1103,14 +1112,9 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
>                 mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER);
>         }
>
> -       if (struct_mutex_locked) {
> -               WARN_ON(!mutex_is_locked(&dev->struct_mutex));
> -               list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> -       } else {
> -               mutex_lock(&dev->struct_mutex);
> -               list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> -               mutex_unlock(&dev->struct_mutex);
> -       }
> +       mutex_lock(&priv->mm_lock);
> +       list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> +       mutex_unlock(&priv->mm_lock);
>
>         return obj;
>
> @@ -1178,9 +1182,9 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
>
>         mutex_unlock(&msm_obj->lock);
>
> -       mutex_lock(&dev->struct_mutex);
> +       mutex_lock(&priv->mm_lock);
>         list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> -       mutex_unlock(&dev->struct_mutex);
> +       mutex_unlock(&priv->mm_lock);
>
>         return obj;
>
> diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
> index 482576d7a39a..c41b84a3a484 100644
> --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
> +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
> @@ -51,11 +51,15 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
>         if (!msm_gem_shrinker_lock(dev, &unlock))
>                 return 0;
>
> +       mutex_lock(&priv->mm_lock);
> +
>         list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
>                 if (is_purgeable(msm_obj))
>                         count += msm_obj->base.size >> PAGE_SHIFT;
>         }
>
> +       mutex_unlock(&priv->mm_lock);
> +
>         if (unlock)
>                 mutex_unlock(&dev->struct_mutex);
>
> @@ -75,6 +79,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>         if (!msm_gem_shrinker_lock(dev, &unlock))
>                 return SHRINK_STOP;
>
> +       mutex_lock(&priv->mm_lock);
> +
>         list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
>                 if (freed >= sc->nr_to_scan)
>                         break;
> @@ -84,6 +90,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>                 }
>         }
>
> +       mutex_unlock(&priv->mm_lock);
> +
>         if (unlock)
>                 mutex_unlock(&dev->struct_mutex);
>
> @@ -106,6 +114,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
>         if (!msm_gem_shrinker_lock(dev, &unlock))
>                 return NOTIFY_DONE;
>
> +       mutex_lock(&priv->mm_lock);
> +
>         list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
>                 if (is_vunmapable(msm_obj)) {
>                         msm_gem_vunmap(&msm_obj->base, OBJ_LOCK_SHRINKER);
> @@ -118,6 +128,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
>                 }
>         }
>
> +       mutex_unlock(&priv->mm_lock);
> +
>         if (unlock)
>                 mutex_unlock(&dev->struct_mutex);
>
> diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> index 6c9e1fdc1a76..1806e87600c0 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.h
> +++ b/drivers/gpu/drm/msm/msm_gpu.h
> @@ -94,7 +94,10 @@ struct msm_gpu {
>         struct msm_ringbuffer *rb[MSM_GPU_MAX_RINGS];
>         int nr_rings;
>
> -       /* list of GEM active objects: */
> +       /*
> +        * List of GEM active objects on this gpu.  Protected by
> +        * msm_drm_private::mm_lock
> +        */
>         struct list_head active_list;
>
>         /* does gpu need hw_init? */
> --
> 2.26.2
>
Rob Clark Oct. 5, 2020, 12:10 a.m. UTC | #2
On Sun, Oct 4, 2020 at 3:15 PM Daniel Vetter <daniel@ffwll.ch> wrote:
>
> On Sun, Oct 4, 2020 at 9:21 PM Rob Clark <robdclark@gmail.com> wrote:
> >
> > From: Rob Clark <robdclark@chromium.org>
> >
> > Rather than relying on the big dev->struct_mutex hammer, introduce a
> > more specific lock for protecting the bo lists.
> >
> > Signed-off-by: Rob Clark <robdclark@chromium.org>
> > ---
> >  drivers/gpu/drm/msm/msm_debugfs.c      |  7 +++++++
> >  drivers/gpu/drm/msm/msm_drv.c          |  1 +
> >  drivers/gpu/drm/msm/msm_drv.h          | 13 +++++++++++-
> >  drivers/gpu/drm/msm/msm_gem.c          | 28 +++++++++++++++-----------
> >  drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++++++++++
> >  drivers/gpu/drm/msm/msm_gpu.h          |  5 ++++-
> >  6 files changed, 52 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
> > index ee2e270f464c..64afbed89821 100644
> > --- a/drivers/gpu/drm/msm/msm_debugfs.c
> > +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> > @@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
> >  {
> >         struct msm_drm_private *priv = dev->dev_private;
> >         struct msm_gpu *gpu = priv->gpu;
> > +       int ret;
> > +
> > +       ret = mutex_lock_interruptible(&priv->mm_lock);
> > +       if (ret)
> > +               return ret;
> >
> >         if (gpu) {
> >                 seq_printf(m, "Active Objects (%s):\n", gpu->name);
> > @@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
> >         seq_printf(m, "Inactive Objects:\n");
> >         msm_gem_describe_objects(&priv->inactive_list, m);
> >
> > +       mutex_unlock(&priv->mm_lock);
> > +
> >         return 0;
> >  }
> >
> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > index 49685571dc0e..dc6efc089285 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
> >         init_llist_head(&priv->free_list);
> >
> >         INIT_LIST_HEAD(&priv->inactive_list);
> > +       mutex_init(&priv->mm_lock);
>
> I highly recommend you drop a
>
> fs_reclaim_acquire(GFP_KERNEL);
> might_lock(&priv->mm_lock);
> fs_reclaim_release(GFP_KERNEL);
>
> in here to teach lockdep about your ordering against the shrinker.
> Gives you full testing every boot, even if your shrinker never gets
> called.

Good idea..

(tbf, I have tested this with android+lockdep which pretty is great
shrinker exercise.. but immediate notification of future problems is a
good plan)

BR,
-R
Jordan Crouse Oct. 5, 2020, 2:19 p.m. UTC | #3
On Sun, Oct 04, 2020 at 12:21:36PM -0700, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> Rather than relying on the big dev->struct_mutex hammer, introduce a
> more specific lock for protecting the bo lists.

Most excellent.

Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>

> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>  drivers/gpu/drm/msm/msm_debugfs.c      |  7 +++++++
>  drivers/gpu/drm/msm/msm_drv.c          |  1 +
>  drivers/gpu/drm/msm/msm_drv.h          | 13 +++++++++++-
>  drivers/gpu/drm/msm/msm_gem.c          | 28 +++++++++++++++-----------
>  drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++++++++++
>  drivers/gpu/drm/msm/msm_gpu.h          |  5 ++++-
>  6 files changed, 52 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
> index ee2e270f464c..64afbed89821 100644
> --- a/drivers/gpu/drm/msm/msm_debugfs.c
> +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> @@ -112,6 +112,11 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
>  {
>  	struct msm_drm_private *priv = dev->dev_private;
>  	struct msm_gpu *gpu = priv->gpu;
> +	int ret;
> +
> +	ret = mutex_lock_interruptible(&priv->mm_lock);
> +	if (ret)
> +		return ret;
>  
>  	if (gpu) {
>  		seq_printf(m, "Active Objects (%s):\n", gpu->name);
> @@ -121,6 +126,8 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
>  	seq_printf(m, "Inactive Objects:\n");
>  	msm_gem_describe_objects(&priv->inactive_list, m);
>  
> +	mutex_unlock(&priv->mm_lock);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 49685571dc0e..dc6efc089285 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -441,6 +441,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>  	init_llist_head(&priv->free_list);
>  
>  	INIT_LIST_HEAD(&priv->inactive_list);
> +	mutex_init(&priv->mm_lock);
>  
>  	drm_mode_config_init(ddev);
>  
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index b9dd8f8f4887..50978e5db376 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -174,8 +174,19 @@ struct msm_drm_private {
>  	struct msm_rd_state *hangrd;   /* debugfs to dump hanging submits */
>  	struct msm_perf_state *perf;
>  
> -	/* list of GEM objects: */
> +	/*
> +	 * List of inactive GEM objects.  Every bo is either in the inactive_list
> +	 * or gpu->active_list (for the gpu it is active on[1])
> +	 *
> +	 * These lists are protected by mm_lock.  If struct_mutex is involved, it
> +	 * should be aquired prior to mm_lock.  One should *not* hold mm_lock in
> +	 * get_pages()/vmap()/etc paths, as they can trigger the shrinker.
> +	 *
> +	 * [1] if someone ever added support for the old 2d cores, there could be
> +	 *     more than one gpu object
> +	 */
>  	struct list_head inactive_list;
> +	struct mutex mm_lock;
>  
>  	/* worker for delayed free of objects: */
>  	struct work_struct free_work;
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index a870b3ad129d..b04ed8b52f9d 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -746,13 +746,17 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
>  void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
>  {
>  	struct msm_gem_object *msm_obj = to_msm_bo(obj);
> -	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> +	struct msm_drm_private *priv = obj->dev->dev_private;
> +
> +	might_sleep();
>  	WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
>  
>  	if (!atomic_fetch_inc(&msm_obj->active_count)) {
> +		mutex_lock(&priv->mm_lock);
>  		msm_obj->gpu = gpu;
>  		list_del_init(&msm_obj->mm_list);
>  		list_add_tail(&msm_obj->mm_list, &gpu->active_list);
> +		mutex_unlock(&priv->mm_lock);
>  	}
>  }
>  
> @@ -761,12 +765,14 @@ void msm_gem_active_put(struct drm_gem_object *obj)
>  	struct msm_gem_object *msm_obj = to_msm_bo(obj);
>  	struct msm_drm_private *priv = obj->dev->dev_private;
>  
> -	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> +	might_sleep();
>  
>  	if (!atomic_dec_return(&msm_obj->active_count)) {
> +		mutex_lock(&priv->mm_lock);
>  		msm_obj->gpu = NULL;
>  		list_del_init(&msm_obj->mm_list);
>  		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> +		mutex_unlock(&priv->mm_lock);
>  	}
>  }
>  
> @@ -921,13 +927,16 @@ static void free_object(struct msm_gem_object *msm_obj)
>  {
>  	struct drm_gem_object *obj = &msm_obj->base;
>  	struct drm_device *dev = obj->dev;
> +	struct msm_drm_private *priv = dev->dev_private;
>  
>  	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>  
>  	/* object should not be on active list: */
>  	WARN_ON(is_active(msm_obj));
>  
> +	mutex_lock(&priv->mm_lock);
>  	list_del(&msm_obj->mm_list);
> +	mutex_unlock(&priv->mm_lock);
>  
>  	mutex_lock(&msm_obj->lock);
>  
> @@ -1103,14 +1112,9 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
>  		mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER);
>  	}
>  
> -	if (struct_mutex_locked) {
> -		WARN_ON(!mutex_is_locked(&dev->struct_mutex));
> -		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> -	} else {
> -		mutex_lock(&dev->struct_mutex);
> -		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> -		mutex_unlock(&dev->struct_mutex);
> -	}
> +	mutex_lock(&priv->mm_lock);
> +	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> +	mutex_unlock(&priv->mm_lock);
>  
>  	return obj;
>  
> @@ -1178,9 +1182,9 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
>  
>  	mutex_unlock(&msm_obj->lock);
>  
> -	mutex_lock(&dev->struct_mutex);
> +	mutex_lock(&priv->mm_lock);
>  	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
> -	mutex_unlock(&dev->struct_mutex);
> +	mutex_unlock(&priv->mm_lock);
>  
>  	return obj;
>  
> diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
> index 482576d7a39a..c41b84a3a484 100644
> --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
> +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
> @@ -51,11 +51,15 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
>  	if (!msm_gem_shrinker_lock(dev, &unlock))
>  		return 0;
>  
> +	mutex_lock(&priv->mm_lock);
> +
>  	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
>  		if (is_purgeable(msm_obj))
>  			count += msm_obj->base.size >> PAGE_SHIFT;
>  	}
>  
> +	mutex_unlock(&priv->mm_lock);
> +
>  	if (unlock)
>  		mutex_unlock(&dev->struct_mutex);
>  
> @@ -75,6 +79,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>  	if (!msm_gem_shrinker_lock(dev, &unlock))
>  		return SHRINK_STOP;
>  
> +	mutex_lock(&priv->mm_lock);
> +
>  	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
>  		if (freed >= sc->nr_to_scan)
>  			break;
> @@ -84,6 +90,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>  		}
>  	}
>  
> +	mutex_unlock(&priv->mm_lock);
> +
>  	if (unlock)
>  		mutex_unlock(&dev->struct_mutex);
>  
> @@ -106,6 +114,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
>  	if (!msm_gem_shrinker_lock(dev, &unlock))
>  		return NOTIFY_DONE;
>  
> +	mutex_lock(&priv->mm_lock);
> +
>  	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
>  		if (is_vunmapable(msm_obj)) {
>  			msm_gem_vunmap(&msm_obj->base, OBJ_LOCK_SHRINKER);
> @@ -118,6 +128,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
>  		}
>  	}
>  
> +	mutex_unlock(&priv->mm_lock);
> +
>  	if (unlock)
>  		mutex_unlock(&dev->struct_mutex);
>  
> diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> index 6c9e1fdc1a76..1806e87600c0 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.h
> +++ b/drivers/gpu/drm/msm/msm_gpu.h
> @@ -94,7 +94,10 @@ struct msm_gpu {
>  	struct msm_ringbuffer *rb[MSM_GPU_MAX_RINGS];
>  	int nr_rings;
>  
> -	/* list of GEM active objects: */
> +	/*
> +	 * List of GEM active objects on this gpu.  Protected by
> +	 * msm_drm_private::mm_lock
> +	 */
>  	struct list_head active_list;
>  
>  	/* does gpu need hw_init? */
> -- 
> 2.26.2
> 
> _______________________________________________
> Freedreno mailing list
> Freedreno@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/freedreno

Patch
diff mbox series

diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
index ee2e270f464c..64afbed89821 100644
--- a/drivers/gpu/drm/msm/msm_debugfs.c
+++ b/drivers/gpu/drm/msm/msm_debugfs.c
@@ -112,6 +112,11 @@  static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_gpu *gpu = priv->gpu;
+	int ret;
+
+	ret = mutex_lock_interruptible(&priv->mm_lock);
+	if (ret)
+		return ret;
 
 	if (gpu) {
 		seq_printf(m, "Active Objects (%s):\n", gpu->name);
@@ -121,6 +126,8 @@  static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
 	seq_printf(m, "Inactive Objects:\n");
 	msm_gem_describe_objects(&priv->inactive_list, m);
 
+	mutex_unlock(&priv->mm_lock);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 49685571dc0e..dc6efc089285 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -441,6 +441,7 @@  static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 	init_llist_head(&priv->free_list);
 
 	INIT_LIST_HEAD(&priv->inactive_list);
+	mutex_init(&priv->mm_lock);
 
 	drm_mode_config_init(ddev);
 
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index b9dd8f8f4887..50978e5db376 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -174,8 +174,19 @@  struct msm_drm_private {
 	struct msm_rd_state *hangrd;   /* debugfs to dump hanging submits */
 	struct msm_perf_state *perf;
 
-	/* list of GEM objects: */
+	/*
+	 * List of inactive GEM objects.  Every bo is either in the inactive_list
+	 * or gpu->active_list (for the gpu it is active on[1])
+	 *
+	 * These lists are protected by mm_lock.  If struct_mutex is involved, it
+	 * should be aquired prior to mm_lock.  One should *not* hold mm_lock in
+	 * get_pages()/vmap()/etc paths, as they can trigger the shrinker.
+	 *
+	 * [1] if someone ever added support for the old 2d cores, there could be
+	 *     more than one gpu object
+	 */
 	struct list_head inactive_list;
+	struct mutex mm_lock;
 
 	/* worker for delayed free of objects: */
 	struct work_struct free_work;
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index a870b3ad129d..b04ed8b52f9d 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -746,13 +746,17 @@  int msm_gem_sync_object(struct drm_gem_object *obj,
 void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	struct msm_drm_private *priv = obj->dev->dev_private;
+
+	might_sleep();
 	WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
 
 	if (!atomic_fetch_inc(&msm_obj->active_count)) {
+		mutex_lock(&priv->mm_lock);
 		msm_obj->gpu = gpu;
 		list_del_init(&msm_obj->mm_list);
 		list_add_tail(&msm_obj->mm_list, &gpu->active_list);
+		mutex_unlock(&priv->mm_lock);
 	}
 }
 
@@ -761,12 +765,14 @@  void msm_gem_active_put(struct drm_gem_object *obj)
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct msm_drm_private *priv = obj->dev->dev_private;
 
-	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+	might_sleep();
 
 	if (!atomic_dec_return(&msm_obj->active_count)) {
+		mutex_lock(&priv->mm_lock);
 		msm_obj->gpu = NULL;
 		list_del_init(&msm_obj->mm_list);
 		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+		mutex_unlock(&priv->mm_lock);
 	}
 }
 
@@ -921,13 +927,16 @@  static void free_object(struct msm_gem_object *msm_obj)
 {
 	struct drm_gem_object *obj = &msm_obj->base;
 	struct drm_device *dev = obj->dev;
+	struct msm_drm_private *priv = dev->dev_private;
 
 	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 
 	/* object should not be on active list: */
 	WARN_ON(is_active(msm_obj));
 
+	mutex_lock(&priv->mm_lock);
 	list_del(&msm_obj->mm_list);
+	mutex_unlock(&priv->mm_lock);
 
 	mutex_lock(&msm_obj->lock);
 
@@ -1103,14 +1112,9 @@  static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
 		mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER);
 	}
 
-	if (struct_mutex_locked) {
-		WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
-	} else {
-		mutex_lock(&dev->struct_mutex);
-		list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
-		mutex_unlock(&dev->struct_mutex);
-	}
+	mutex_lock(&priv->mm_lock);
+	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+	mutex_unlock(&priv->mm_lock);
 
 	return obj;
 
@@ -1178,9 +1182,9 @@  struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 
 	mutex_unlock(&msm_obj->lock);
 
-	mutex_lock(&dev->struct_mutex);
+	mutex_lock(&priv->mm_lock);
 	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
-	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&priv->mm_lock);
 
 	return obj;
 
diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index 482576d7a39a..c41b84a3a484 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -51,11 +51,15 @@  msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
 	if (!msm_gem_shrinker_lock(dev, &unlock))
 		return 0;
 
+	mutex_lock(&priv->mm_lock);
+
 	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
 		if (is_purgeable(msm_obj))
 			count += msm_obj->base.size >> PAGE_SHIFT;
 	}
 
+	mutex_unlock(&priv->mm_lock);
+
 	if (unlock)
 		mutex_unlock(&dev->struct_mutex);
 
@@ -75,6 +79,8 @@  msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
 	if (!msm_gem_shrinker_lock(dev, &unlock))
 		return SHRINK_STOP;
 
+	mutex_lock(&priv->mm_lock);
+
 	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
 		if (freed >= sc->nr_to_scan)
 			break;
@@ -84,6 +90,8 @@  msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
 		}
 	}
 
+	mutex_unlock(&priv->mm_lock);
+
 	if (unlock)
 		mutex_unlock(&dev->struct_mutex);
 
@@ -106,6 +114,8 @@  msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
 	if (!msm_gem_shrinker_lock(dev, &unlock))
 		return NOTIFY_DONE;
 
+	mutex_lock(&priv->mm_lock);
+
 	list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
 		if (is_vunmapable(msm_obj)) {
 			msm_gem_vunmap(&msm_obj->base, OBJ_LOCK_SHRINKER);
@@ -118,6 +128,8 @@  msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
 		}
 	}
 
+	mutex_unlock(&priv->mm_lock);
+
 	if (unlock)
 		mutex_unlock(&dev->struct_mutex);
 
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 6c9e1fdc1a76..1806e87600c0 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -94,7 +94,10 @@  struct msm_gpu {
 	struct msm_ringbuffer *rb[MSM_GPU_MAX_RINGS];
 	int nr_rings;
 
-	/* list of GEM active objects: */
+	/*
+	 * List of GEM active objects on this gpu.  Protected by
+	 * msm_drm_private::mm_lock
+	 */
 	struct list_head active_list;
 
 	/* does gpu need hw_init? */