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[v2,0/4] drm/msm/gpu: add support for ocmem interconnect

Message ID 20191122012645.7430-1-masneyb@onstation.org
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Series drm/msm/gpu: add support for ocmem interconnect | expand

Message

Brian Masney Nov. 22, 2019, 1:26 a.m. UTC 
Some A3xx and all A4xx Adreno GPUs do not have GMEM inside the GPU core
and must use the On Chip MEMory (OCMEM) in order to be functional.
There's a separate interconnect path that needs to be setup to OCMEM.
This patch series adds support for that path, and sets the votes for the
two interconnect paths to the highest speed for a3xx and a4xx-based
platforms.

Changes since v1:
- Don't rename icc_path to gfx_mem_icc_path. Leave existing variable
  named as is and add comment to declaration in struct msm_gpu.

Brian Masney (4):
  dt-bindings: drm/msm/gpu: document second interconnect
  drm/msm/gpu: add support for ocmem interconnect path
  drm/msm/a3xx: set interconnect bandwidth vote
  drm/msm/a4xx: set interconnect bandwidth vote

 .../devicetree/bindings/display/msm/gpu.txt        |  6 +++++-
 drivers/gpu/drm/msm/adreno/a3xx_gpu.c              |  8 ++++++++
 drivers/gpu/drm/msm/adreno/a4xx_gpu.c              |  8 ++++++++
 drivers/gpu/drm/msm/adreno/adreno_gpu.c            | 14 +++++++++++++-
 drivers/gpu/drm/msm/msm_gpu.h                      |  7 +++++++
 5 files changed, 41 insertions(+), 2 deletions(-)

Comments

Bjorn Andersson Dec. 12, 2019, 7:12 a.m. UTC | #1 
On Thu 21 Nov 17:26 PST 2019, Brian Masney wrote:

> Some A3xx and all A4xx Adreno GPUs do not have GMEM inside the GPU core
> and must use the On Chip MEMory (OCMEM) in order to be functional.
> There's a separate interconnect path that needs to be setup to OCMEM.
> Add support for this second path to the GPU core.
> 
> In the downstream MSM 3.4 sources, the two interconnect paths for the
> GPU are between:
> 
>   - MSM_BUS_MASTER_GRAPHICS_3D and MSM_BUS_SLAVE_EBI_CH0
>   - MSM_BUS_MASTER_V_OCMEM_GFX3D and MSM_BUS_SLAVE_OCMEM
> 

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> Signed-off-by: Brian Masney <masneyb@onstation.org>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 14 +++++++++++++-
>  drivers/gpu/drm/msm/msm_gpu.h           |  7 +++++++
>  2 files changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index 0783e4b5486a..d27bdc999777 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -887,10 +887,21 @@ static int adreno_get_pwrlevels(struct device *dev,
>  	DBG("fast_rate=%u, slow_rate=27000000", gpu->fast_rate);
>  
>  	/* Check for an interconnect path for the bus */
> -	gpu->icc_path = of_icc_get(dev, NULL);
> +	gpu->icc_path = of_icc_get(dev, "gfx-mem");
> +	if (!gpu->icc_path) {
> +		/*
> +		 * Keep compatbility with device trees that don't have an
> +		 * interconnect-names property.
> +		 */
> +		gpu->icc_path = of_icc_get(dev, NULL);
> +	}
>  	if (IS_ERR(gpu->icc_path))
>  		gpu->icc_path = NULL;
>  
> +	gpu->ocmem_icc_path = of_icc_get(dev, "ocmem");
> +	if (IS_ERR(gpu->ocmem_icc_path))
> +		gpu->ocmem_icc_path = NULL;
> +
>  	return 0;
>  }
>  
> @@ -977,6 +988,7 @@ void adreno_gpu_cleanup(struct adreno_gpu *adreno_gpu)
>  		release_firmware(adreno_gpu->fw[i]);
>  
>  	icc_put(gpu->icc_path);
> +	icc_put(gpu->ocmem_icc_path);
>  
>  	msm_gpu_cleanup(&adreno_gpu->base);
>  }
> diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> index ab8f0f9c9dc8..be5bc2e8425c 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.h
> +++ b/drivers/gpu/drm/msm/msm_gpu.h
> @@ -111,8 +111,15 @@ struct msm_gpu {
>  	struct clk *ebi1_clk, *core_clk, *rbbmtimer_clk;
>  	uint32_t fast_rate;
>  
> +	/* The gfx-mem interconnect path that's used by all GPU types. */
>  	struct icc_path *icc_path;
>  
> +	/*
> +	 * Second interconnect path for some A3xx and all A4xx GPUs to the
> +	 * On Chip MEMory (OCMEM).
> +	 */
> +	struct icc_path *ocmem_icc_path;
> +
>  	/* Hang and Inactivity Detection:
>  	 */
>  #define DRM_MSM_INACTIVE_PERIOD   66 /* in ms (roughly four frames) */
> -- 
> 2.21.0
>
Bjorn Andersson Dec. 12, 2019, 7:17 a.m. UTC | #2 
On Thu 21 Nov 17:26 PST 2019, Brian Masney wrote:

> Set the two interconnect paths for the GPU to maximum speed for now to
> work towards getting the GPU working upstream. We can revisit a later
> time to optimize this for battery life.
> 
> Signed-off-by: Brian Masney <masneyb@onstation.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---
>  drivers/gpu/drm/msm/adreno/a3xx_gpu.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
> index 07ddcc529573..eff0ecd4e81a 100644
> --- a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
> @@ -504,6 +504,14 @@ struct msm_gpu *a3xx_gpu_init(struct drm_device *dev)
>  		DRM_DEV_ERROR(dev->dev, "No memory protection without IOMMU\n");
>  	}
>  
> +	/*
> +	 * Set the ICC path to maximum speed for now by multiplying the fastest
> +	 * frequency by the bus width (8). We'll want to scale this later on to
> +	 * improve battery life.

I would expect that you have to worry about temperature before battery
life...

Regards,
Bjorn

> +	 */
> +	icc_set_bw(gpu->icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +	icc_set_bw(gpu->ocmem_icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +
>  	return gpu;
>  
>  fail:
> -- 
> 2.21.0
>
Bjorn Andersson Dec. 12, 2019, 7:18 a.m. UTC | #3 
On Thu 21 Nov 17:26 PST 2019, Brian Masney wrote:

> Set the two interconnect paths for the GPU to maximum speed for now to
> work towards getting the GPU working upstream. We can revisit a later
> time to optimize this for battery life.
> 
> Signed-off-by: Brian Masney <masneyb@onstation.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---
>  drivers/gpu/drm/msm/adreno/a4xx_gpu.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a4xx_gpu.c b/drivers/gpu/drm/msm/adreno/a4xx_gpu.c
> index b01388a9e89e..253d8d85daad 100644
> --- a/drivers/gpu/drm/msm/adreno/a4xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a4xx_gpu.c
> @@ -591,6 +591,14 @@ struct msm_gpu *a4xx_gpu_init(struct drm_device *dev)
>  		goto fail;
>  	}
>  
> +	/*
> +	 * Set the ICC path to maximum speed for now by multiplying the fastest
> +	 * frequency by the bus width (8). We'll want to scale this later on to
> +	 * improve battery life.
> +	 */
> +	icc_set_bw(gpu->icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +	icc_set_bw(gpu->ocmem_icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +
>  	return gpu;
>  
>  fail:
> -- 
> 2.21.0
>