[PATCH v4 10/11] drm/msm/A6xx: Enable preemption for A750

[Akhil P Oommen]

On Tue, Sep 17, 2024 at 01:14:20PM +0200, Antonino Maniscalco wrote:
> Initialize with 4 rings to enable preemption.
> 
> For now only on A750 as other targets require testing.
> 
> Add the "preemption_enabled" module parameter to override this for other
> A7xx targets.
> 
> Signed-off-by: Antonino Maniscalco <antomani103 at gmail.com>
> Tested-by: Neil Armstrong <neil.armstrong at linaro.org> # on SM8650-QRD
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 3 ++-
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c     | 6 +++++-
>  drivers/gpu/drm/msm/adreno/adreno_gpu.h   | 1 +
>  drivers/gpu/drm/msm/msm_drv.c             | 4 ++++
>  4 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
> index 316f23ca9167..0e3041b29419 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
> @@ -1240,7 +1240,8 @@ static const struct adreno_info a7xx_gpus[] = {
>  		.gmem = 3 * SZ_1M,
>  		.inactive_period = DRM_MSM_INACTIVE_PERIOD,
>  		.quirks = ADRENO_QUIRK_HAS_CACHED_COHERENT |
> -			  ADRENO_QUIRK_HAS_HW_APRIV,
> +			  ADRENO_QUIRK_HAS_HW_APRIV |
> +			  ADRENO_QUIRK_PREEMPTION,
>  		.init = a6xx_gpu_init,
>  		.zapfw = "gen70900_zap.mbn",
>  		.a6xx = &(const struct a6xx_info) {
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index edbcb6d229ba..4760f9469613 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -2529,6 +2529,7 @@ struct msm_gpu *a6xx_gpu_init(struct drm_device *dev)
>  	struct a6xx_gpu *a6xx_gpu;
>  	struct adreno_gpu *adreno_gpu;
>  	struct msm_gpu *gpu;
> +	extern int enable_preemption;
>  	bool is_a7xx;
>  	int ret;
>  
> @@ -2567,7 +2568,10 @@ struct msm_gpu *a6xx_gpu_init(struct drm_device *dev)
>  		return ERR_PTR(ret);
>  	}
>  
> -	if (is_a7xx)
> +	if ((enable_preemption == 1) || (enable_preemption == -1 &&
> +	    (config->info->quirks & ADRENO_QUIRK_PREEMPTION)))
> +		ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs_a7xx, 4);
> +	else if (is_a7xx)
>  		ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs_a7xx, 1);
>  	else if (adreno_has_gmu_wrapper(adreno_gpu))
>  		ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs_gmuwrapper, 1);
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> index 87098567483b..d1cd53f05de6 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> @@ -56,6 +56,7 @@ enum adreno_family {
>  #define ADRENO_QUIRK_LMLOADKILL_DISABLE		BIT(2)
>  #define ADRENO_QUIRK_HAS_HW_APRIV		BIT(3)
>  #define ADRENO_QUIRK_HAS_CACHED_COHERENT	BIT(4)
> +#define ADRENO_QUIRK_PREEMPTION			BIT(5)
>  
>  /* Helper for formating the chip_id in the way that userspace tools like
>   * crashdec expect.
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 9c33f4e3f822..7c64b20f5e3b 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -58,6 +58,10 @@ static bool modeset = true;
>  MODULE_PARM_DESC(modeset, "Use kernel modesetting [KMS] (1=on (default), 0=disable)");
>  module_param(modeset, bool, 0600);
>  
> +int enable_preemption = -1;
> +MODULE_PARM_DESC(enable_preemption, "Enable preemption (A7xx only) (1=on , 0=disable, -1=auto (default))");
> +module_param(enable_preemption, int, 0600);
> +

Is adreno_device.c a better place for adreno specific module params?

-Akhil.

>  #ifdef CONFIG_FAULT_INJECTION
>  DECLARE_FAULT_ATTR(fail_gem_alloc);
>  DECLARE_FAULT_ATTR(fail_gem_iova);
> 
> -- 
> 2.46.0
>