Re: [PATCH v7 01/17] drm/panfrost: Move shrinker initialization and unplug one level down

[Boris Brezillon <boris.brezillon@collabora.com>]

On Fri, 28 Aug 2026 21:56:41 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> Since the moment we call drm_dev_register() the device should be in a
> position to accept jobs, so it's best if the shrinker is already
> initialized by then.
> 
> On top of that, make shrinker functions take an panfrost_device pointer
> like other functions in the same sequence and rename them accordingly.
> 
> Essentially mimic the init/fini behaviour in Panthor.
> 
> On top of that, remove the config feature check, because it's unnecessary.

I don't think that's accurate anymore (we still have a config check,
except it's encoded directly in the panfrost_transparent_hugepage definition),
and I think I'd prefer if this change was done in a separate commit.

> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_device.c       |  8 +++++++-
>  drivers/gpu/drm/panfrost/panfrost_drv.c          |  6 ------
>  drivers/gpu/drm/panfrost/panfrost_drv.h          |  4 ++++
>  drivers/gpu/drm/panfrost/panfrost_gem.c          | 25 ++++++++++++++----------
>  drivers/gpu/drm/panfrost/panfrost_gem.h          |  7 ++++---
>  drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c |  8 ++------
>  6 files changed, 32 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> index 485349faf251..05c40d5a20b5 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -280,9 +280,14 @@ int panfrost_device_init(struct panfrost_device *pfdev)
>  	if (err)
>  		goto out_job;
>  
> -	panfrost_gem_init(pfdev);
> +	err = panfrost_gem_init(pfdev);
> +	if (err)
> +		goto out_perfcnt;
>  
>  	return 0;
> +
> +out_perfcnt:
> +	panfrost_perfcnt_fini(pfdev);
>  out_job:
>  	panfrost_jm_fini(pfdev);
>  out_mmu:
> @@ -304,6 +309,7 @@ int panfrost_device_init(struct panfrost_device *pfdev)
>  
>  void panfrost_device_fini(struct panfrost_device *pfdev)
>  {
> +	panfrost_gem_fini(pfdev);
>  	panfrost_perfcnt_fini(pfdev);
>  	panfrost_jm_fini(pfdev);
>  	panfrost_mmu_fini(pfdev);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 96a66d673ba6..9882a3ede75f 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -1003,14 +1003,9 @@ static int panfrost_probe(struct platform_device *pdev)
>  	if (err < 0)
>  		goto err_out1;
>  
> -	err = panfrost_gem_shrinker_init(&pfdev->base);
> -	if (err)
> -		goto err_out2;
>  
>  	return 0;
>  
> -err_out2:
> -	drm_dev_unregister(&pfdev->base);
>  err_out1:
>  	pm_runtime_disable(pfdev->base.dev);
>  	panfrost_device_fini(pfdev);
> @@ -1024,7 +1019,6 @@ static void panfrost_remove(struct platform_device *pdev)
>  	struct panfrost_device *pfdev = platform_get_drvdata(pdev);
>  
>  	drm_dev_unregister(&pfdev->base);
> -	panfrost_gem_shrinker_cleanup(&pfdev->base);
>  
>  	pm_runtime_get_sync(pfdev->base.dev);
>  	pm_runtime_disable(pfdev->base.dev);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.h b/drivers/gpu/drm/panfrost/panfrost_drv.h
> index a2277ec61aab..bac0c415d4da 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.h
> @@ -4,6 +4,10 @@
>  #ifndef __PANFROST_DRV_H__
>  #define __PANFROST_DRV_H__
>  
> +#if IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)
>  extern bool panfrost_transparent_hugepage;
> +#else
> +#define panfrost_transparent_hugepage false
> +#endif
>  
>  #endif
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 3a7fce428898..7b993a089af2 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -15,20 +15,25 @@
>  #include "panfrost_gem.h"
>  #include "panfrost_mmu.h"
>  
> -void panfrost_gem_init(struct panfrost_device *pfdev)
> +int panfrost_gem_init(struct panfrost_device *pfdev)
>  {
>  	int err;
>  
> -	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
> -	    !panfrost_transparent_hugepage)
> -		return;
> +	if (panfrost_transparent_hugepage) {
> +		err = drm_gem_huge_mnt_create(&pfdev->base, "within_size");
> +		if (drm_gem_get_huge_mnt(&pfdev->base))
> +			drm_info(&pfdev->base, "Using Transparent Hugepage\n");
> +		else if (err)
> +			drm_warn(&pfdev->base,
> +				 "Can't use Transparent Hugepage (%d)\n", err);

This can probably be turned into:

		if (err)
			drm_warn(&pfdev->base,
				 "Can't use Transparent Hugepage (%d)\n", err);
		else
			drm_info(&pfdev->base, "Using Transparent Hugepage\n");

since there's no world where drm_gem_get_huge_mnt() would return NULL if
drm_gem_huge_mnt_create() returns 0 when CONFIG_TRANSPARENT_HUGEPAGE=y.
The pre-existing checks where there to cover CONFIG_TRANSPARENT_HUGEPAGE=n
which you already cover by not entering this branch.

> +	}
>  
> -	err = drm_gem_huge_mnt_create(&pfdev->base, "within_size");
> -	if (drm_gem_get_huge_mnt(&pfdev->base))
> -		drm_info(&pfdev->base, "Using Transparent Hugepage\n");
> -	else if (err)
> -		drm_warn(&pfdev->base, "Can't use Transparent Hugepage (%d)\n",
> -			 err);
> +	return panfrost_gem_shrinker_init(pfdev);
> +}
> +
> +void panfrost_gem_fini(struct panfrost_device *pfdev)
> +{
> +	panfrost_gem_shrinker_fini(pfdev);
>  }
>  
>  #ifdef CONFIG_DEBUG_FS
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 79d4377019e9..5c823cdbd980 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -129,7 +129,8 @@ drm_mm_node_to_panfrost_mapping(struct drm_mm_node *node)
>  	return container_of(node, struct panfrost_gem_mapping, mmnode);
>  }
>  
> -void panfrost_gem_init(struct panfrost_device *pfdev);
> +int panfrost_gem_init(struct panfrost_device *pfdev);
> +void panfrost_gem_fini(struct panfrost_device *pfdev);
>  
>  struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t size);
>  
> @@ -154,8 +155,8 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
>  void panfrost_gem_mapping_put(struct panfrost_gem_mapping *mapping);
>  void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>  
> -int panfrost_gem_shrinker_init(struct drm_device *dev);
> -void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
> +int panfrost_gem_shrinker_init(struct panfrost_device *pfdev);
> +void panfrost_gem_shrinker_fini(struct panfrost_device *pfdev);
>  
>  void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
>  int panfrost_gem_sync(struct drm_gem_object *obj, u32 type,
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> index 2fe967a90bcb..fefae87535d6 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> @@ -95,10 +95,8 @@ panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>   *
>   * This function registers and sets up the panfrost shrinker.
>   */
> -int panfrost_gem_shrinker_init(struct drm_device *dev)
> +int panfrost_gem_shrinker_init(struct panfrost_device *pfdev)
>  {
> -	struct panfrost_device *pfdev = to_panfrost_device(dev);
> -
>  	pfdev->shrinker = shrinker_alloc(0, "drm-panfrost");
>  	if (!pfdev->shrinker)
>  		return -ENOMEM;
> @@ -118,10 +116,8 @@ int panfrost_gem_shrinker_init(struct drm_device *dev)
>   *
>   * This function unregisters the panfrost shrinker.
>   */
> -void panfrost_gem_shrinker_cleanup(struct drm_device *dev)
> +void panfrost_gem_shrinker_fini(struct panfrost_device *pfdev)
>  {
> -	struct panfrost_device *pfdev = to_panfrost_device(dev);
> -
>  	if (pfdev->shrinker)
>  		shrinker_free(pfdev->shrinker);
>  }
>