[PATCH v1 0/4] drm/msm/a6xx: Add support for zap shader

[PATCH v1 0/4] drm/msm/a6xx: Add support for zap shader

[Jordan Crouse]

This patch series adds support for loading the zap shader on a6xx and using it
to get the GPU out of secure mode.

The Adreno a5xx and a6xx GPUs boot in "secure" mode which restricts the memory
the GPU is allowed to use. To get the GPU out of secure mode we need to write
to a register. However some bootloaders block access to this register and
require that the GPU instead perform a sequence to pull the GPU out of secure
mode. This sequence requires a special "zap" shader that will execute in
secure mode, clear out all the internal GPU settings and then transition to
in-secure mode.

This series adds support for loading and using the zap shader on a6xx assuming
that the shader exists and that the bootloader supports the secure mode. If any
part of the sequence fails then fall back to writing the register. If we get it
wrong, then writing to the register will trigger a protection mode error and
the system will go down.

The actual zap shader works almost identically to the one on 5xx outside of
a minor workaround for system resume. The first patch moves the a5xx specific
support to the generic adreno driver. The second patch add support for the
zap shader and the final two patches add the DT bindings and DT settings for
setting up the reserved memory that the shader requires.


Jordan Crouse (4):
  drm/msm/gpu: Move zap shader loading to adreno
  drm/msm/a6xx: Add zap shader load
  dt-bindings: drm/msm/gpu: Document a5xx / a6xx zap shader region
  arm64: dts: sdm845: Add zap shader region for GPU

 .../devicetree/bindings/display/msm/gpu.txt        |   7 ++
 arch/arm64/boot/dts/qcom/sdm845.dtsi               |  11 ++
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c              | 109 +-------------------
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c              |  38 ++++++-
 drivers/gpu/drm/msm/adreno/adreno_device.c         |   1 +
 drivers/gpu/drm/msm/adreno/adreno_gpu.c            | 113 +++++++++++++++++++++
 drivers/gpu/drm/msm/adreno/adreno_gpu.h            |   6 ++
 7 files changed, 176 insertions(+), 109 deletions(-)

-- 
2.7.4

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[PATCH v1 3/4] dt-bindings: drm/msm/gpu: Document a5xx / a6xx zap shader region

[Jordan Crouse]

Describe the zap-shader node that defines a reserved memory region
to store the zap shader.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
---

 Documentation/devicetree/bindings/display/msm/gpu.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/msm/gpu.txt b/Documentation/devicetree/bindings/display/msm/gpu.txt
index aad1aef..1e6d870 100644
--- a/Documentation/devicetree/bindings/display/msm/gpu.txt
+++ b/Documentation/devicetree/bindings/display/msm/gpu.txt
@@ -25,6 +25,9 @@ Required properties:
 - qcom,gmu: For GMU attached devices a phandle to the GMU device that will
   control the power for the GPU. Applicable targets:
     - qcom,adreno-630.2
+- zap-shader: For a5xx and a6xx devices this node contains a memory-region that
+  points to reserved memory to store the zap shader that can be used to help
+  bring the GPU out of secure mode.
 
 Example 3xx/4xx/a5xx:
 
@@ -71,5 +74,9 @@ Example a6xx (with GMU):
 		operating-points-v2 = <&gpu_opp_table>;
 
 		qcom,gmu = <&gmu>;
+
+		zap-shader {
+			memory-region = <&zap_shader_region>;
+		};
 	};
 };
-- 
2.7.4

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[PATCH v1 4/4] arm64: dts: sdm845: Add zap shader region for GPU

[Jordan Crouse]

Some Adreno GPU targets require a special zap shader to bring the GPU
out of secure mode. Define a region to allocate and store the zap
shader.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
---

 arch/arm64/boot/dts/qcom/sdm845.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
index fed7a29..526456d 100644
--- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
@@ -100,6 +100,11 @@
 			no-map;
 		};
 
+		zap_shader_region: memory@8c415000 {
+			reg = <0 0x8c415000 0 0x2000>;
+			no-map;
+		};
+
 		mpss_region: memory@8e000000 {
 			reg = <0 0x8e000000 0 0x7800000>;
 			no-map;
@@ -109,6 +114,8 @@
 			reg = <0 0x96500000 0 0x200000>;
 			no-map;
 		};
+
+
 	};
 
 	cpus {
@@ -1514,6 +1521,10 @@
 
 			qcom,gmu = <&gmu>;
 
+			zap-shader {
+				memory-region = <&zap_shader_region>;
+			};
+
 			gpu_opp_table: opp-table {
 				compatible = "operating-points-v2";
 
-- 
2.7.4

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Re: [Freedreno] [PATCH v1 4/4] arm64: dts: sdm845: Add zap shader region for GPU

[Rob Clark]

On Tue, Mar 12, 2019 at 2:14 PM Jordan Crouse <jcrouse@codeaurora.org> wrote:
>
> Some Adreno GPU targets require a special zap shader to bring the GPU
> out of secure mode. Define a region to allocate and store the zap
> shader.
>
> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> ---
>
>  arch/arm64/boot/dts/qcom/sdm845.dtsi | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> index fed7a29..526456d 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> @@ -100,6 +100,11 @@
>                         no-map;
>                 };
>
> +               zap_shader_region: memory@8c415000 {
> +                       reg = <0 0x8c415000 0 0x2000>;
> +                       no-map;
> +               };
> +
>                 mpss_region: memory@8e000000 {
>                         reg = <0 0x8e000000 0 0x7800000>;
>                         no-map;
> @@ -109,6 +114,8 @@
>                         reg = <0 0x96500000 0 0x200000>;
>                         no-map;
>                 };
> +
> +

I guess we don't really need this hunk..

other than that, the series lgtm

BR,
-R

>         };
>
>         cpus {
> @@ -1514,6 +1521,10 @@
>
>                         qcom,gmu = <&gmu>;
>
> +                       zap-shader {
> +                               memory-region = <&zap_shader_region>;
> +                       };
> +
>                         gpu_opp_table: opp-table {
>                                 compatible = "operating-points-v2";
>
> --
> 2.7.4
>
> _______________________________________________
> Freedreno mailing list
> Freedreno@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/freedreno

Re: [PATCH v1 4/4] arm64: dts: sdm845: Add zap shader region for GPU

[Bjorn Andersson]

On Wed 13 Mar 08:42 PDT 2019, Rob Clark wrote:

> On Tue, Mar 12, 2019 at 2:14 PM Jordan Crouse <jcrouse@codeaurora.org> wrote:
> >
> > Some Adreno GPU targets require a special zap shader to bring the GPU
> > out of secure mode. Define a region to allocate and store the zap
> > shader.
> >
> > Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> > ---
> >
> >  arch/arm64/boot/dts/qcom/sdm845.dtsi | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > index fed7a29..526456d 100644
> > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > @@ -100,6 +100,11 @@
> >                         no-map;
> >                 };
> >
> > +               zap_shader_region: memory@8c415000 {
> > +                       reg = <0 0x8c415000 0 0x2000>;
> > +                       no-map;
> > +               };
> > +
> >                 mpss_region: memory@8e000000 {
> >                         reg = <0 0x8e000000 0 0x7800000>;
> >                         no-map;
> > @@ -109,6 +114,8 @@
> >                         reg = <0 0x96500000 0 0x200000>;
> >                         no-map;
> >                 };
> > +
> > +
> 
> I guess we don't really need this hunk..
> 

I'll trim that as I pick up the patch.

> other than that, the series lgtm
> 

Will you pick up patch 1-3 and I'll pick patch 4 through Andy's tree?

Regards,
Bjorn

> BR,
> -R
> 
> >         };
> >
> >         cpus {
> > @@ -1514,6 +1521,10 @@
> >
> >                         qcom,gmu = <&gmu>;
> >
> > +                       zap-shader {
> > +                               memory-region = <&zap_shader_region>;
> > +                       };
> > +
> >                         gpu_opp_table: opp-table {
> >                                 compatible = "operating-points-v2";
> >
> > --
> > 2.7.4
> >
> > _______________________________________________
> > Freedreno mailing list
> > Freedreno@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/freedreno
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Re: [PATCH v1 4/4] arm64: dts: sdm845: Add zap shader region for GPU

[Rob Clark]

On Thu, Mar 14, 2019 at 1:20 AM Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Wed 13 Mar 08:42 PDT 2019, Rob Clark wrote:
>
> > On Tue, Mar 12, 2019 at 2:14 PM Jordan Crouse <jcrouse@codeaurora.org> wrote:
> > >
> > > Some Adreno GPU targets require a special zap shader to bring the GPU
> > > out of secure mode. Define a region to allocate and store the zap
> > > shader.
> > >
> > > Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> > > ---
> > >
> > >  arch/arm64/boot/dts/qcom/sdm845.dtsi | 11 +++++++++++
> > >  1 file changed, 11 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > index fed7a29..526456d 100644
> > > --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> > > @@ -100,6 +100,11 @@
> > >                         no-map;
> > >                 };
> > >
> > > +               zap_shader_region: memory@8c415000 {
> > > +                       reg = <0 0x8c415000 0 0x2000>;
> > > +                       no-map;
> > > +               };
> > > +
> > >                 mpss_region: memory@8e000000 {
> > >                         reg = <0 0x8e000000 0 0x7800000>;
> > >                         no-map;
> > > @@ -109,6 +114,8 @@
> > >                         reg = <0 0x96500000 0 0x200000>;
> > >                         no-map;
> > >                 };
> > > +
> > > +
> >
> > I guess we don't really need this hunk..
> >
>
> I'll trim that as I pick up the patch.
>
> > other than that, the series lgtm
> >
>
> Will you pick up patch 1-3 and I'll pick patch 4 through Andy's tree?

yeah, sounds good.

BR,
-R

> Regards,
> Bjorn
>
> > BR,
> > -R
> >
> > >         };
> > >
> > >         cpus {
> > > @@ -1514,6 +1521,10 @@
> > >
> > >                         qcom,gmu = <&gmu>;
> > >
> > > +                       zap-shader {
> > > +                               memory-region = <&zap_shader_region>;
> > > +                       };
> > > +
> > >                         gpu_opp_table: opp-table {
> > >                                 compatible = "operating-points-v2";
> > >
> > > --
> > > 2.7.4
> > >
> > > _______________________________________________
> > > Freedreno mailing list
> > > Freedreno@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/freedreno
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Re: [PATCH v1 3/4] dt-bindings: drm/msm/gpu: Document a5xx / a6xx zap shader region

[Rob Herring]

On Tue, Mar 12, 2019 at 12:13:41PM -0600, Jordan Crouse wrote:
> Describe the zap-shader node that defines a reserved memory region
> to store the zap shader.
> 
> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> ---
> 
>  Documentation/devicetree/bindings/display/msm/gpu.txt | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/msm/gpu.txt b/Documentation/devicetree/bindings/display/msm/gpu.txt
> index aad1aef..1e6d870 100644
> --- a/Documentation/devicetree/bindings/display/msm/gpu.txt
> +++ b/Documentation/devicetree/bindings/display/msm/gpu.txt
> @@ -25,6 +25,9 @@ Required properties:
>  - qcom,gmu: For GMU attached devices a phandle to the GMU device that will
>    control the power for the GPU. Applicable targets:
>      - qcom,adreno-630.2
> +- zap-shader: For a5xx and a6xx devices this node contains a memory-region that
> +  points to reserved memory to store the zap shader that can be used to help
> +  bring the GPU out of secure mode.

This is the properties section and zap-shader is not a property.

But why do you need a child node in the first place? Just add 
'memory-region' to the parent.

>  
>  Example 3xx/4xx/a5xx:
>  
> @@ -71,5 +74,9 @@ Example a6xx (with GMU):
>  		operating-points-v2 = <&gpu_opp_table>;
>  
>  		qcom,gmu = <&gmu>;
> +
> +		zap-shader {
> +			memory-region = <&zap_shader_region>;
> +		};
>  	};
>  };
> -- 
> 2.7.4
> 

Re: [PATCH v1 3/4] dt-bindings: drm/msm/gpu: Document a5xx / a6xx zap shader region

[Jordan Crouse]

On Thu, Mar 28, 2019 at 08:32:15AM -0500, Rob Herring wrote:
> On Tue, Mar 12, 2019 at 12:13:41PM -0600, Jordan Crouse wrote:
> > Describe the zap-shader node that defines a reserved memory region
> > to store the zap shader.
> > 
> > Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> > ---
> > 
> >  Documentation/devicetree/bindings/display/msm/gpu.txt | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/display/msm/gpu.txt b/Documentation/devicetree/bindings/display/msm/gpu.txt
> > index aad1aef..1e6d870 100644
> > --- a/Documentation/devicetree/bindings/display/msm/gpu.txt
> > +++ b/Documentation/devicetree/bindings/display/msm/gpu.txt
> > @@ -25,6 +25,9 @@ Required properties:
> >  - qcom,gmu: For GMU attached devices a phandle to the GMU device that will
> >    control the power for the GPU. Applicable targets:
> >      - qcom,adreno-630.2
> > +- zap-shader: For a5xx and a6xx devices this node contains a memory-region that
> > +  points to reserved memory to store the zap shader that can be used to help
> > +  bring the GPU out of secure mode.
> 
> This is the properties section and zap-shader is not a property.

Thanks, I can fix that.

> But why do you need a child node in the first place? Just add 
> 'memory-region' to the parent.

Two reasons.  First, this memory is locked in the secure world once the MDT
loader is run and it isn't really intended for CPU access. If the parent device
tries to set up DMA operations thinking it has access to the memory it might not
work out very well.  Putting it in a child makes it clear that this is a special
chunk of memory for a special case.

The second reason is that not all target platforms require the zap shader, so it
would be nice to have it as a child node so that it could be removed on target
platforms that don't need it.

Jordan

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