| Message ID | 20210222120259.94465-3-manivannan.sadhasivam@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Add support for secure regions in Qcom NANDc driver | expand |
Hi Miquel, On Tue, Feb 23, 2021 at 05:49:22PM +0100, Miquel Raynal wrote: > Hi Manivannan, > > Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote on Mon, > 22 Feb 2021 17:32:58 +0530: > > > On a typical end product, a vendor may choose to secure some regions in > > the NAND memory which are supposed to stay intact between FW upgrades. > > The access to those regions will be blocked by a secure element like > > Trustzone. So the normal world software like Linux kernel should not > > touch these regions (including reading). > > > > So let's add a property for declaring such secure regions so that the > > driver can skip touching them. > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > --- > > Documentation/devicetree/bindings/mtd/qcom,nandc.yaml | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > > index 84ad7ff30121..7500e20da9c1 100644 > > --- a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > > +++ b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > > @@ -48,6 +48,13 @@ patternProperties: > > enum: > > - 512 > > > > + qcom,secure-regions: > > + $ref: /schemas/types.yaml#/definitions/uint32-array > > + description: > > + Regions in the NAND memory which are protected using a secure element > > + like Trustzone. This property contains the start address and size of > > + the secure regions present (optional). > > What does this "(optional)" means? If you mean the property is optional > then it should be described accordingly in the yaml file, or am I > missing something? > IIUC, if a property is not listed under "required" section then it is optional. But I've added the quote here to just make it explicit. > I wonder if it wouldn't be better to make this a NAND chip node > property. I don't think a qcom prefix is needed as potentially many > other SoCs might have the same "feature". > > I'm fine adding support for it in the qcom driver only though. > Hmm, sounds good to me. Thanks, Mani > > + > > allOf: > > - $ref: "nand-controller.yaml#" > > > > Thanks, > Miquèl
On Mon, Feb 22, 2021 at 05:32:58PM +0530, Manivannan Sadhasivam wrote: > On a typical end product, a vendor may choose to secure some regions in > the NAND memory which are supposed to stay intact between FW upgrades. > The access to those regions will be blocked by a secure element like > Trustzone. So the normal world software like Linux kernel should not > touch these regions (including reading). > > So let's add a property for declaring such secure regions so that the > driver can skip touching them. > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > --- > Documentation/devicetree/bindings/mtd/qcom,nandc.yaml | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > index 84ad7ff30121..7500e20da9c1 100644 > --- a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > +++ b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > @@ -48,6 +48,13 @@ patternProperties: > enum: > - 512 > > + qcom,secure-regions: > + $ref: /schemas/types.yaml#/definitions/uint32-array Don't you need 64-bit regions potentially? Though 4GB should be enough for anyone. If more than one addr+size, then you need a matrix. > + description: > + Regions in the NAND memory which are protected using a secure element > + like Trustzone. This property contains the start address and size of > + the secure regions present (optional). > + > allOf: > - $ref: "nand-controller.yaml#" > > -- > 2.25.1 >
On Tue, Mar 09, 2021 at 07:32:28PM -0700, Rob Herring wrote: > On Sun, Mar 7, 2021 at 10:31 PM Manivannan Sadhasivam > <manivannan.sadhasivam@linaro.org> wrote: > > > > On Fri, Mar 05, 2021 at 05:36:57PM -0600, Rob Herring wrote: > > > On Mon, Feb 22, 2021 at 05:32:58PM +0530, Manivannan Sadhasivam wrote: > > > > On a typical end product, a vendor may choose to secure some regions in > > > > the NAND memory which are supposed to stay intact between FW upgrades. > > > > The access to those regions will be blocked by a secure element like > > > > Trustzone. So the normal world software like Linux kernel should not > > > > touch these regions (including reading). > > > > > > > > So let's add a property for declaring such secure regions so that the > > > > driver can skip touching them. > > > > > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > --- > > > > Documentation/devicetree/bindings/mtd/qcom,nandc.yaml | 7 +++++++ > > > > 1 file changed, 7 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > > > > index 84ad7ff30121..7500e20da9c1 100644 > > > > --- a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > > > > +++ b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml > > > > @@ -48,6 +48,13 @@ patternProperties: > > > > enum: > > > > - 512 > > > > > > > > + qcom,secure-regions: > > > > + $ref: /schemas/types.yaml#/definitions/uint32-array > > > > > > Don't you need 64-bit regions potentially? Though 4GB should be enough > > > for anyone. > > > > > > > Yes, given the size of current NAND based systems around, I thought 32 bit is > > enough. > > Huh!? I was joking. 4GB is small nowadays. Make this 64-bit. > Well I was speaking in the context of Qcom chipsets making use of NAND. Mostly the Qcom modem chipsets have <4GB of memory. But since this property is now not specific to Qcom, I agree with you and will make it 64 bit. Thanks, Mani > Rob
diff --git a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml index 84ad7ff30121..7500e20da9c1 100644 --- a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml +++ b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml @@ -48,6 +48,13 @@ patternProperties: enum: - 512 + qcom,secure-regions: + $ref: /schemas/types.yaml#/definitions/uint32-array + description: + Regions in the NAND memory which are protected using a secure element + like Trustzone. This property contains the start address and size of + the secure regions present (optional). + allOf: - $ref: "nand-controller.yaml#"
On a typical end product, a vendor may choose to secure some regions in the NAND memory which are supposed to stay intact between FW upgrades. The access to those regions will be blocked by a secure element like Trustzone. So the normal world software like Linux kernel should not touch these regions (including reading). So let's add a property for declaring such secure regions so that the driver can skip touching them. Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- Documentation/devicetree/bindings/mtd/qcom,nandc.yaml | 7 +++++++ 1 file changed, 7 insertions(+)