Re: [PATCH v12 02/15] drm/panfrost: Move lock and modparam initialisations into their subsystems

[Steven Price <steven.price@arm.com>]

On 29/09/2026 04:44, Adrián Larumbe wrote:
> The device init function feels a bit cluttered with things that should be
> done in the specific subsystems where those locks and lists are being
> used. Same goes for module parameters, it's best to limit them to the
> subsystems where they're relevant.
> 
> Then we can also discard panfrost_drv.h since the transparent_huge_page
> doesn't need to be accessed elsewhere. We can also simplify the
> creation of a mount point, because drm_gem_get_huge_mnt() would never
> return NULL if drm_gem_huge_mnt_create() returns 0 when kernel is built
> with support for transparent huge pages.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

Reviewed-by: Steven Price <steven.price@arm.com>

> ---
>  drivers/gpu/drm/panfrost/panfrost_device.c       |  7 -------
>  drivers/gpu/drm/panfrost/panfrost_drv.c          | 10 ----------
>  drivers/gpu/drm/panfrost/panfrost_drv.h          |  9 ---------
>  drivers/gpu/drm/panfrost/panfrost_gem.c          | 19 +++++++++++++------
>  drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c |  3 +++
>  drivers/gpu/drm/panfrost/panfrost_gpu.c          |  2 ++
>  drivers/gpu/drm/panfrost/panfrost_job.c          |  1 +
>  drivers/gpu/drm/panfrost/panfrost_mmu.c          |  3 +++
>  8 files changed, 22 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> index 05c40d5a20b5..c1a2e93a2b9b 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -216,13 +216,6 @@ int panfrost_device_init(struct panfrost_device *pfdev)
>  {
>  	int err;
>  
> -	mutex_init(&pfdev->sched_lock);
> -	INIT_LIST_HEAD(&pfdev->as_lru_list);
> -
> -	spin_lock_init(&pfdev->as_lock);
> -
> -	spin_lock_init(&pfdev->cycle_counter.lock);
> -
>  #ifdef CONFIG_DEBUG_FS
>  	mutex_init(&pfdev->debugfs.gems_lock);
>  	INIT_LIST_HEAD(&pfdev->debugfs.gems_list);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 9882a3ede75f..59af79a534fa 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -21,7 +21,6 @@
>  #include <drm/drm_utils.h>
>  
>  #include "panfrost_device.h"
> -#include "panfrost_drv.h"
>  #include "panfrost_gem.h"
>  #include "panfrost_mmu.h"
>  #include "panfrost_job.h"
> @@ -955,12 +954,6 @@ static const struct drm_driver panfrost_drm_driver = {
>  #endif
>  };
>  
> -#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -bool panfrost_transparent_hugepage = true;
> -module_param_named(transparent_hugepage, panfrost_transparent_hugepage, bool, 0400);
> -MODULE_PARM_DESC(transparent_hugepage, "Use a dedicated tmpfs mount point with Transparent Hugepage enabled (true = default)");
> -#endif
> -
>  static int panfrost_probe(struct platform_device *pdev)
>  {
>  	struct panfrost_device *pfdev;
> @@ -979,9 +972,6 @@ static int panfrost_probe(struct platform_device *pdev)
>  
>  	pfdev->coherent = device_get_dma_attr(&pdev->dev) == DEV_DMA_COHERENT;
>  
> -	mutex_init(&pfdev->shrinker_lock);
> -	INIT_LIST_HEAD(&pfdev->shrinker_list);
> -
>  	err = panfrost_device_init(pfdev);
>  	if (err) {
>  		if (err != -EPROBE_DEFER)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.h b/drivers/gpu/drm/panfrost/panfrost_drv.h
> deleted file mode 100644
> index a2277ec61aab..000000000000
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.h
> +++ /dev/null
> @@ -1,9 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 or MIT */
> -/* Copyright 2025 Amazon.com, Inc. or its affiliates */
> -
> -#ifndef __PANFROST_DRV_H__
> -#define __PANFROST_DRV_H__
> -
> -extern bool panfrost_transparent_hugepage;
> -
> -#endif
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index f39c0f50ed4f..383ac8cd5645 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -11,20 +11,27 @@
>  #include <drm/panfrost_drm.h>
>  #include <drm/drm_print.h>
>  #include "panfrost_device.h"
> -#include "panfrost_drv.h"
>  #include "panfrost_gem.h"
>  #include "panfrost_mmu.h"
>  
> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> +static bool panfrost_transparent_hugepage = true;
> +module_param_named(transparent_hugepage, panfrost_transparent_hugepage, bool, 0400);
> +MODULE_PARM_DESC(transparent_hugepage, "Use a dedicated tmpfs mount point with Transparent Hugepage enabled (true = default)");
> +#else
> +#define panfrost_transparent_hugepage false
> +#endif
> +
>  int panfrost_gem_init(struct panfrost_device *pfdev)
>  {
> -	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && panfrost_transparent_hugepage) {
> +	if (panfrost_transparent_hugepage) {
>  		int err = drm_gem_huge_mnt_create(&pfdev->base, "within_size");
>  
> -		if (drm_gem_get_huge_mnt(&pfdev->base))
> +		if (err)
> +			drm_warn(&pfdev->base,
> +				 "Can't use Transparent Hugepage (%d)\n", err);
> +		else
>  			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);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> index fefae87535d6..72cd7a165e6d 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> @@ -97,6 +97,9 @@ panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>   */
>  int panfrost_gem_shrinker_init(struct panfrost_device *pfdev)
>  {
> +	mutex_init(&pfdev->shrinker_lock);
> +	INIT_LIST_HEAD(&pfdev->shrinker_list);
> +
>  	pfdev->shrinker = shrinker_alloc(0, "drm-panfrost");
>  	if (!pfdev->shrinker)
>  		return -ENOMEM;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c
> index 7d555e63e21a..8a15ccce08e9 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c
> @@ -516,6 +516,8 @@ int panfrost_gpu_init(struct panfrost_device *pfdev)
>  {
>  	int err;
>  
> +	spin_lock_init(&pfdev->cycle_counter.lock);
> +
>  	err = panfrost_gpu_soft_reset(pfdev);
>  	if (err)
>  		return err;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index d59b4863b8ad..476c936b54e6 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -874,6 +874,7 @@ int panfrost_jm_init(struct panfrost_device *pfdev)
>  
>  	INIT_WORK(&pfdev->reset.work, panfrost_reset_work);
>  	spin_lock_init(&js->job_lock);
> +	mutex_init(&pfdev->sched_lock);
>  
>  	js->irq = platform_get_irq_byname(to_platform_device(pfdev->base.dev), "job");
>  	if (js->irq < 0)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index 4a3162c3b659..5c393ed6e310 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -955,6 +955,9 @@ int panfrost_mmu_init(struct panfrost_device *pfdev)
>  {
>  	int err;
>  
> +	INIT_LIST_HEAD(&pfdev->as_lru_list);
> +	spin_lock_init(&pfdev->as_lock);
> +
>  	pfdev->mmu_irq = platform_get_irq_byname(to_platform_device(pfdev->base.dev), "mmu");
>  	if (pfdev->mmu_irq < 0)
>  		return pfdev->mmu_irq;
>