linux-kernel - Re: [PATCH v4 06/10] drm/panfrost: Don't rework job IRQ enable mask in the enable path

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251001130017.5eefe8ce@fedora>
Date: Wed, 1 Oct 2025 13:00:17 +0200
From: Boris Brezillon <boris.brezillon@...labora.com>
To: Adrián Larumbe <adrian.larumbe@...labora.com>
Cc: linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org, Steven
 Price <steven.price@....com>, kernel@...labora.com, Rob Herring
 <robh@...nel.org>, Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann
 <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, Simona Vetter
 <simona@...ll.ch>
Subject: Re: [PATCH v4 06/10] drm/panfrost: Don't rework job IRQ enable mask
 in the enable path

On Wed,  1 Oct 2025 03:20:27 +0100
Adrián Larumbe <adrian.larumbe@...labora.com> wrote:

> Up until now, panfrost_job_enable_interrupts() would always recalculate the
> same job IRQ enablement mask, which is effectively a constant.
> 
> Replace it with a compile-time constant value, and also in another couple
> places where an equivalent expression was being used.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@...labora.com>

Reviewed-by: Boris Brezillon <boris.brezillon@...labora.com>

> ---
>  drivers/gpu/drm/panfrost/panfrost_device.h |  4 ++++
>  drivers/gpu/drm/panfrost/panfrost_job.c    | 19 ++++---------------
>  2 files changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 474b232bb38e..ac7147ed806b 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -26,6 +26,10 @@ struct panfrost_perfcnt;
>  
>  #define MAX_PM_DOMAINS 5
>  
> +#define ALL_JS_INT_MASK					\
> +	(GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |		\
> +	 GENMASK(NUM_JOB_SLOTS - 1, 0))
> +
>  enum panfrost_drv_comp_bits {
>  	PANFROST_COMP_BIT_GPU,
>  	PANFROST_COMP_BIT_JOB,
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index ba934437a8ea..54764ce91dea 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -428,17 +428,10 @@ static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
>  
>  void panfrost_job_enable_interrupts(struct panfrost_device *pfdev)
>  {
> -	int j;
> -	u32 irq_mask = 0;
> -
>  	clear_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended);
>  
> -	for (j = 0; j < NUM_JOB_SLOTS; j++) {
> -		irq_mask |= MK_JS_MASK(j);
> -	}
> -
> -	job_write(pfdev, JOB_INT_CLEAR, irq_mask);
> -	job_write(pfdev, JOB_INT_MASK, irq_mask);
> +	job_write(pfdev, JOB_INT_CLEAR, ALL_JS_INT_MASK);
> +	job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
>  }
>  
>  void panfrost_job_suspend_irq(struct panfrost_device *pfdev)
> @@ -757,9 +750,7 @@ panfrost_reset(struct panfrost_device *pfdev,
>  		drm_sched_start(&pfdev->js->queue[i].sched, 0);
>  
>  	/* Re-enable job interrupts now that everything has been restarted. */
> -	job_write(pfdev, JOB_INT_MASK,
> -		  GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
> -		  GENMASK(NUM_JOB_SLOTS - 1, 0));
> +	job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
>  
>  	dma_fence_end_signalling(cookie);
>  }
> @@ -832,9 +823,7 @@ static irqreturn_t panfrost_job_irq_handler_thread(int irq, void *data)
>  
>  	/* Enable interrupts only if we're not about to get suspended */
>  	if (!test_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended))
> -		job_write(pfdev, JOB_INT_MASK,
> -			  GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
> -			  GENMASK(NUM_JOB_SLOTS - 1, 0));
> +		job_write(pfdev, JOB_INT_MASK, ALL_JS_INT_MASK);
>  
>  	return IRQ_HANDLED;
>  }