[amd-gfx] [PATCH v2 1/3] drm/amdgpu: add disable_cu parameter

[Deucher, Alexander]

> -----Original Message-----
> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> Of Nicolai Hähnle
> Sent: Friday, June 17, 2016 1:32 PM
> To: amd-gfx at lists.freedesktop.org
> Cc: Haehnle, Nicolai
> Subject: [amd-gfx] [PATCH v2 1/3] drm/amdgpu: add disable_cu parameter
> 
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
> 
> This parameter will allow disabling individual CUs on module load, e.g.
> amdgpu.disable_cu=2.0.3,2.0.4 to disable CUs 3 and 4 of SE2.
> 
> Signed-off-by: Nicolai Hähnle <nicolai.haehnle at amd.com>

For the series:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu.h     |  1 +
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  4 +++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 44
> +++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h |  2 ++
>  4 files changed, 51 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 01c36b8..2d35e11 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -87,6 +87,7 @@ extern int amdgpu_sched_hw_submission;
>  extern int amdgpu_powerplay;
>  extern unsigned amdgpu_pcie_gen_cap;
>  extern unsigned amdgpu_pcie_lane_cap;
> +extern char *amdgpu_disable_cu;
> 
>  #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS	        3000
>  #define AMDGPU_MAX_USEC_TIMEOUT			100000	/* 100
> ms */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index f888c01..235f732 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -84,6 +84,7 @@ int amdgpu_sched_hw_submission = 2;
>  int amdgpu_powerplay = -1;
>  unsigned amdgpu_pcie_gen_cap = 0;
>  unsigned amdgpu_pcie_lane_cap = 0;
> +char *amdgpu_disable_cu = NULL;
> 
>  MODULE_PARM_DESC(vramlimit, "Restrict VRAM for testing, in
> megabytes");
>  module_param_named(vramlimit, amdgpu_vram_limit, int, 0600);
> @@ -168,6 +169,9 @@ module_param_named(pcie_gen_cap,
> amdgpu_pcie_gen_cap, uint, 0444);
>  MODULE_PARM_DESC(pcie_lane_cap, "PCIE Lane Caps (0: autodetect
> (default))");
>  module_param_named(pcie_lane_cap, amdgpu_pcie_lane_cap, uint, 0444);
> 
> +MODULE_PARM_DESC(disable_cu, "Disable CUs (se.sh.cu,...)");
> +module_param_named(disable_cu, amdgpu_disable_cu, charp, 0444);
> +
>  static const struct pci_device_id pciidlist[] = {
>  #ifdef CONFIG_DRM_AMDGPU_CIK
>  	/* Kaveri */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> index 9f95da4..a074edd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> @@ -70,3 +70,47 @@ void amdgpu_gfx_scratch_free(struct amdgpu_device
> *adev, uint32_t reg)
>  		}
>  	}
>  }
> +
> +/**
> + * amdgpu_gfx_parse_disable_cu - Parse the disable_cu module parameter
> + *
> + * @mask: array in which the per-shader array disable masks will be stored
> + * @max_se: number of SEs
> + * @max_sh: number of SHs
> + *
> + * The bitmask of CUs to be disabled in the shader array determined by se
> and
> + * sh is stored in mask[se * max_sh + sh].
> + */
> +void amdgpu_gfx_parse_disable_cu(unsigned *mask, unsigned max_se,
> unsigned max_sh)
> +{
> +	unsigned se, sh, cu;
> +	const char *p;
> +
> +	memset(mask, 0, sizeof(*mask) * max_se * max_sh);
> +
> +	if (!amdgpu_disable_cu || !*amdgpu_disable_cu)
> +		return;
> +
> +	p = amdgpu_disable_cu;
> +	for (;;) {
> +		char *next;
> +		int ret = sscanf(p, "%u.%u.%u", &se, &sh, &cu);
> +		if (ret < 3) {
> +			DRM_ERROR("amdgpu: could not parse
> disable_cu\n");
> +			return;
> +		}
> +
> +		if (se < max_se && sh < max_sh && cu < 16) {
> +			DRM_INFO("amdgpu: disabling CU %u.%u.%u\n", se,
> sh, cu);
> +			mask[se * max_sh + sh] |= 1u << cu;
> +		} else {
> +			DRM_ERROR("amdgpu: disable_cu %u.%u.%u is out
> of range\n",
> +				  se, sh, cu);
> +		}
> +
> +		next = strchr(p, ',');
> +		if (!next)
> +			break;
> +		p = next + 1;
> +	}
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
> index dc06cbd..51321e1 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.h
> @@ -27,4 +27,6 @@
>  int amdgpu_gfx_scratch_get(struct amdgpu_device *adev, uint32_t *reg);
>  void amdgpu_gfx_scratch_free(struct amdgpu_device *adev, uint32_t reg);
> 
> +unsigned amdgpu_gfx_parse_disable_cu(unsigned *mask, unsigned
> max_se, unsigned max_sh);
> +
>  #endif
> --
> 2.7.4
> 
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