[PATCH 0/3] nvmem: qfprom: Avoid untouchable regions

[PATCH 0/3] nvmem: qfprom: Avoid untouchable regions

[Evan Green]

Certain fuses are protected by the XPU such that the AP cannot
access them. Attempting to do so causes an SError. Introduce an
SoC-specific compatible string, and then use that to determine
which fuse regions to present as Read as Zero / Write Ignore.


Evan Green (3):
  dt-bindings: nvmem: Add qcom,sc7180-qfprom compatible string
  arm64: dts: qcom: sc7180: Add soc-specific qfprom compat string
  nvmem: qfprom: Don't touch certain fuses

 .../bindings/nvmem/qcom,qfprom.yaml           |  4 +-
 arch/arm64/boot/dts/qcom/sc7180.dtsi          |  2 +-
 drivers/nvmem/qfprom.c                        | 55 +++++++++++++++++--
 3 files changed, 55 insertions(+), 6 deletions(-)

-- 
2.26.2

[PATCH 1/3] dt-bindings: nvmem: Add qcom,sc7180-qfprom compatible string

[Evan Green]

Add an SoC-specific compatible string so that data can be attached
to it in the driver.

Signed-off-by: Evan Green <evgreen@chromium.org>
---

 Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
index 59aca6d22ff9b..b16c8e6a8c23d 100644
--- a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
+++ b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
@@ -14,7 +14,9 @@ allOf:
 
 properties:
   compatible:
-    const: qcom,qfprom
+    enum:
+      - qcom,qfprom
+      - qcom,sc7180-qfprom
 
   reg:
     # If the QFPROM is read-only OS image then only the corrected region
-- 
2.26.2

[PATCH 2/3] arm64: dts: qcom: sc7180: Add soc-specific qfprom compat string

[Evan Green]

Add the soc-specific compatible string so that it can be matched
more specifically now that the driver cares which SoC it's on.

Signed-off-by: Evan Green <evgreen@chromium.org>
---

 arch/arm64/boot/dts/qcom/sc7180.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index 6678f1e8e3958..f1f8bbc0b37bc 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -660,7 +660,7 @@ gcc: clock-controller@100000 {
 		};
 
 		qfprom: efuse@784000 {
-			compatible = "qcom,qfprom";
+			compatible = "qcom,sc7180-qfprom", "qcom,qfprom";
 			reg = <0 0x00784000 0 0x8ff>,
 			      <0 0x00780000 0 0x7a0>,
 			      <0 0x00782000 0 0x100>,
-- 
2.26.2

Re: [PATCH 1/3] dt-bindings: nvmem: Add qcom,sc7180-qfprom compatible string

[Doug Anderson]

Hi,

On Tue, Sep 29, 2020 at 1:58 PM Evan Green <evgreen@chromium.org> wrote:
>
> Add an SoC-specific compatible string so that data can be attached
> to it in the driver.
>
> Signed-off-by: Evan Green <evgreen@chromium.org>
> ---
>
>  Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> index 59aca6d22ff9b..b16c8e6a8c23d 100644
> --- a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> @@ -14,7 +14,9 @@ allOf:
>
>  properties:
>    compatible:
> -    const: qcom,qfprom
> +    enum:
> +      - qcom,qfprom
> +      - qcom,sc7180-qfprom

You don't want either/or.  You want both.  At the time Srinivas didn't
see the point of having the SoC-specific compatible string here, but
now that we have a reason for it maybe he'll be convinced?  IMO you
essentially want:

    items:
      - enum:
          - qcom,apq8064-qfprom
          - qcom,apq8084-qfprom
          - qcom,msm8974-qfprom
          - qcom,msm8916-qfprom
          - qcom,msm8996-qfprom
          - qcom,msm8998-qfprom
          - qcom,qcs404-qfprom
          - qcom,sc7180-qfprom
          - qcom,sdm845-qfprom
      - const: qcom,qfprom

For some context:
<https://lore.kernel.org/r/CAD=FV=WjvAWVmq3fTh=_f2p1Dv+sXg1RV-CqZr8KRgHe8_wT0w@mail.gmail.com/>

-Doug


>
>    reg:
>      # If the QFPROM is read-only OS image then only the corrected region
> --
> 2.26.2
>

Re: [PATCH 2/3] arm64: dts: qcom: sc7180: Add soc-specific qfprom compat string

[Doug Anderson]

Hi,

On Tue, Sep 29, 2020 at 1:58 PM Evan Green <evgreen@chromium.org> wrote:
>
> Add the soc-specific compatible string so that it can be matched
> more specifically now that the driver cares which SoC it's on.
>
> Signed-off-by: Evan Green <evgreen@chromium.org>
> ---
>
>  arch/arm64/boot/dts/qcom/sc7180.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Douglas Anderson <dianders@chromium.org>

Re: [PATCH 1/3] dt-bindings: nvmem: Add qcom,sc7180-qfprom compatible string

[Evan Green]

On Fri, Oct 2, 2020 at 3:20 PM Doug Anderson <dianders@chromium.org> wrote:
>
> Hi,
>
> On Tue, Sep 29, 2020 at 1:58 PM Evan Green <evgreen@chromium.org> wrote:
> >
> > Add an SoC-specific compatible string so that data can be attached
> > to it in the driver.
> >
> > Signed-off-by: Evan Green <evgreen@chromium.org>
> > ---
> >
> >  Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> > index 59aca6d22ff9b..b16c8e6a8c23d 100644
> > --- a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> > +++ b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> > @@ -14,7 +14,9 @@ allOf:
> >
> >  properties:
> >    compatible:
> > -    const: qcom,qfprom
> > +    enum:
> > +      - qcom,qfprom
> > +      - qcom,sc7180-qfprom
>
> You don't want either/or.  You want both.  At the time Srinivas didn't
> see the point of having the SoC-specific compatible string here, but
> now that we have a reason for it maybe he'll be convinced?  IMO you
> essentially want:
>
>     items:
>       - enum:
>           - qcom,apq8064-qfprom
>           - qcom,apq8084-qfprom
>           - qcom,msm8974-qfprom
>           - qcom,msm8916-qfprom
>           - qcom,msm8996-qfprom
>           - qcom,msm8998-qfprom
>           - qcom,qcs404-qfprom
>           - qcom,sc7180-qfprom
>           - qcom,sdm845-qfprom
>       - const: qcom,qfprom
>
> For some context:
> <https://lore.kernel.org/r/CAD=FV=WjvAWVmq3fTh=_f2p1Dv+sXg1RV-CqZr8KRgHe8_wT0w@mail.gmail.com/>

That makes sense, thanks Doug.

Srini, do you want me to go fix up all the various device trees to add
the soc-compatible string, or just sc7180? (Also, don't forget about
my other question about whether you still want the keepout stuff in
the core at the cost of added complexity).

-Evan

>
> -Doug
>
>
> >
> >    reg:
> >      # If the QFPROM is read-only OS image then only the corrected region
> > --
> > 2.26.2
> >

Re: [PATCH 1/3] dt-bindings: nvmem: Add qcom,sc7180-qfprom compatible string

[Srinivas Kandagatla]

On 03/10/2020 00:14, Evan Green wrote:
>> You don't want either/or.  You want both.  At the time Srinivas didn't
>> see the point of having the SoC-specific compatible string here, but
>> now that we have a reason for it maybe he'll be convinced?  IMO you
>> essentially want:
>>
>>      items:
>>        - enum:
>>            - qcom,apq8064-qfprom
>>            - qcom,apq8084-qfprom
>>            - qcom,msm8974-qfprom
>>            - qcom,msm8916-qfprom
>>            - qcom,msm8996-qfprom
>>            - qcom,msm8998-qfprom
>>            - qcom,qcs404-qfprom
>>            - qcom,sc7180-qfprom
>>            - qcom,sdm845-qfprom
>>        - const: qcom,qfprom
>>
>> For some context:
>> <https://lore.kernel.org/r/CAD=FV=WjvAWVmq3fTh=_f2p1Dv+sXg1RV-CqZr8KRgHe8_wT0w@mail.gmail.com/>
> That makes sense, thanks Doug.
> 
> Srini, do you want me to go fix up all the various device trees to add
> the soc-compatible string, or just sc7180? (Also, don't forget about
> my other question about whether you still want the keepout stuff in
> the core at the cost of added complexity).

Lets keep the existing users as it for now! and we can still list 
compatibles in the bindings so that any new users (including sc7180) can 
start using them when needed!

thanks,
srini


> 
> -Evan
>