diff mbox series

[v4,1/7] dt-bindings: arm: fsl: add se-fw binding doc

Message ID 20230712121219.2654234-2-pankaj.gupta@nxp.com (mailing list archive)
State New, archived
Headers show
Series firmware: imx: NXP Edgelock Enclave MUAP Driver | expand

Commit Message

Pankaj Gupta July 12, 2023, 12:12 p.m. UTC
The NXP's i.MX EdgeLock Enclave, a HW IP creating an embedded
secure enclave within the SoC boundary to enable features like
- HSM
- SHE
- V2X

Communicates via message unit with linux kernel. This driver
is enables communication ensuring well defined message sequence
protocol between Application Core and enclave's firmware.

Driver configures multiple misc-device on the MU, for multiple
user-space applications can communicate on single MU.

It exists on some i.MX processors. e.g. i.MX8ULP, i.MX93 etc.

Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
---
 .../bindings/arm/freescale/fsl,se-fw.yaml     | 121 ++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml

Comments

Conor Dooley July 12, 2023, 6:26 p.m. UTC | #1
Hey,

On Wed, Jul 12, 2023 at 05:42:13PM +0530, Pankaj Gupta wrote:
> The NXP's i.MX EdgeLock Enclave, a HW IP creating an embedded
> secure enclave within the SoC boundary to enable features like
> - HSM
> - SHE
> - V2X
> 
> Communicates via message unit with linux kernel. This driver
> is enables communication ensuring well defined message sequence
> protocol between Application Core and enclave's firmware.
> 
> Driver configures multiple misc-device on the MU, for multiple
> user-space applications can communicate on single MU.
> 
> It exists on some i.MX processors. e.g. i.MX8ULP, i.MX93 etc.
> 
> Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
> ---
>  .../bindings/arm/freescale/fsl,se-fw.yaml     | 121 ++++++++++++++++++
>  1 file changed, 121 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
> new file mode 100644
> index 000000000000..7567da0b4c21
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
> @@ -0,0 +1,121 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/freescale/fsl,se-fw.yaml#

I think on v3 you were asked to use a filename that matches the
compatibles?

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP i.MX EdgeLock Enclave Firmware (ELEFW)
> +
> +maintainers:
> +  - Pankaj Gupta <pankaj.gupta@nxp.com>

> +  value, i.e., supported SoC(s) are imx8ulp, imx93.

> +
> +properties:
> +  compatible:
> +    enum:
> +      - fsl,imx-ele

This looks like a generic compatible, not a specific one, but you use it
on the imx8ulp. I would have expected that you would have something like
"fsl,imx8ulp-ele" for that.

> +      - fsl,imx93-ele


> +
> +  mboxes:
> +    description:
> +      A list of phandles of TX MU channels followed by a list of phandles of
> +      RX MU channels. The number of expected tx and rx channels is 1 TX, and
> +      1 RX channels. All MU channels must be within the same MU instance.
> +      Cross instances are not allowed. The MU instance to be used is S4MUAP
> +      for imx8ulp & imx93. Users need to ensure that used MU instance does not
> +      conflict with other execution environments.
> +    items:
> +      - description: TX0 MU channel
> +      - description: RX0 MU channel
> +
> +  mbox-names:
> +    items:
> +      - const: tx
> +      - const: rx
> +
> +  fsl,mu-did:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      Owner of message-unit, is identified via Domain ID or did.

On v3 you had constraints:
	enum: [0, 1, 2, 3, 4, 5, 6, 7]
Do constraints no longer apply? If they do, you can use minimum &
maximum to specify them.

> +  fsl,mu-id:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      Identifier to the message-unit among the multiple message-unit that exists on SoC.
> +      It is used to create the channels, default to 2

Are there constraints here? If so, same applies.
You should use "default:" for defaults, rather than describing them in
freeform text.

Thanks,
Conor.
Krzysztof Kozlowski July 12, 2023, 6:34 p.m. UTC | #2
On 12/07/2023 20:26, Conor Dooley wrote:
> Hey,
> 
> On Wed, Jul 12, 2023 at 05:42:13PM +0530, Pankaj Gupta wrote:
>> The NXP's i.MX EdgeLock Enclave, a HW IP creating an embedded
>> secure enclave within the SoC boundary to enable features like
>> - HSM
>> - SHE
>> - V2X
>>
>> Communicates via message unit with linux kernel. This driver
>> is enables communication ensuring well defined message sequence
>> protocol between Application Core and enclave's firmware.
>>
>> Driver configures multiple misc-device on the MU, for multiple
>> user-space applications can communicate on single MU.
>>
>> It exists on some i.MX processors. e.g. i.MX8ULP, i.MX93 etc.
>>
>> Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
>> ---
>>  .../bindings/arm/freescale/fsl,se-fw.yaml     | 121 ++++++++++++++++++
>>  1 file changed, 121 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
>> new file mode 100644
>> index 000000000000..7567da0b4c21
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
>> @@ -0,0 +1,121 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/arm/freescale/fsl,se-fw.yaml#
> 
> I think on v3 you were asked to use a filename that matches the
> compatibles?
> 
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: NXP i.MX EdgeLock Enclave Firmware (ELEFW)
>> +
>> +maintainers:
>> +  - Pankaj Gupta <pankaj.gupta@nxp.com>
> 
>> +  value, i.e., supported SoC(s) are imx8ulp, imx93.
> 
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - fsl,imx-ele
> 
> This looks like a generic compatible, not a specific one, but you use it
> on the imx8ulp. I would have expected that you would have something like
> "fsl,imx8ulp-ele" for that.

Yeah, this one looks generic, so not what we expect.

> 
>> +      - fsl,imx93-ele
> 
> 
>> +
>> +  mboxes:
>> +    description:
>> +      A list of phandles of TX MU channels followed by a list of phandles of
>> +      RX MU channels. The number of expected tx and rx channels is 1 TX, and
>> +      1 RX channels. 

Don't repeat constraints in free form text. This is obvious from the
items below.


Best regards,
Krzysztof
Krzysztof Kozlowski July 12, 2023, 6:38 p.m. UTC | #3
On 12/07/2023 14:12, Pankaj Gupta wrote:
> The NXP's i.MX EdgeLock Enclave, a HW IP creating an embedded
> secure enclave within the SoC boundary to enable features like
> - HSM
> - SHE
> - V2X
> 
> Communicates via message unit with linux kernel. This driver
> is enables communication ensuring well defined message sequence
> protocol between Application Core and enclave's firmware.
> 
> Driver configures multiple misc-device on the MU, for multiple
> user-space applications can communicate on single MU.
> 
> It exists on some i.MX processors. e.g. i.MX8ULP, i.MX93 etc.
> 
> Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
> ---
>  .../bindings/arm/freescale/fsl,se-fw.yaml     | 121 ++++++++++++++++++
>  1 file changed, 121 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
> new file mode 100644
> index 000000000000..7567da0b4c21
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
> @@ -0,0 +1,121 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/freescale/fsl,se-fw.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP i.MX EdgeLock Enclave Firmware (ELEFW)
> +
> +maintainers:
> +  - Pankaj Gupta <pankaj.gupta@nxp.com>
> +
> +description: |
> +
> +  The NXP's i.MX EdgeLock Enclave, a HW IP creating an embedded
> +  secure enclave within the SoC boundary to enable features like
> +  - HSM
> +  - SHE
> +  - V2X
> +
> +  It uses message unit to communicate and coordinate to pass messages
> +  (e.g., data,  status and control) through its interfaces.
> +
> +  This driver configures multiple misc-devices on the MU, to exchange
> +  messages from User-space application and NXP's Edgelocke Enclave firmware.
> +  The driver ensures that the messages must follow the following protocol
> +  defined.
> +
> +                                     Non-Secure           +   Secure
> +                                                          |
> +                                                          |
> +                   +---------+      +-------------+       |
> +                   | ele_mu.c+<---->+imx-mailbox.c|       |
> +                   |         |      |  mailbox.c  +<-->+------+    +------+
> +                   +---+-----+      +-------------+    | MU X +<-->+ ELE |
> +                       |                               +------+    +------+
> +                       +----------------+                 |
> +                       |                |                 |
> +                       v                v                 |
> +                   logical           logical              |
> +                   receiver          waiter               |
> +                      +                 +                 |
> +                      |                 |                 |
> +                      |                 |                 |
> +                      |            +----+------+          |
> +                      |            |           |          |
> +                      |            |           |          |
> +               device_ctx     device_ctx     device_ctx   |
> +                                                          |
> +                 User 0        User 1       User Y        |
> +                 +------+      +------+     +------+      |
> +                 |misc.c|      |misc.c|     |misc.c|      |
> +  kernel space   +------+      +------+     +------+      |
> +                                                          |
> +  +------------------------------------------------------ |
> +                     |             |           |          |
> +  userspace     /dev/ele_muXch0    |           |          |
> +                           /dev/ele_muXch1     |          |
> +                                         /dev/ele_muXchY  |
> +                                                          |
> +
> +  When a user sends a command to the ELE, it registers its device_ctx as
> +  waiter of a response from ELE.
> +
> +  A user can be registered as receiver of command from the ELE.
> +  Create char devices in /dev as channels of the form /dev/ele_muXchY with X
> +  the id of the driver and Y for each users. It allows to send and receive
> +  messages to the NXP EdgeLock Enclave IP on NXP SoC, where current possible
> +  value, i.e., supported SoC(s) are imx8ulp, imx93.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - fsl,imx-ele
> +      - fsl,imx93-ele
> +
> +  mboxes:
> +    description:
> +      A list of phandles of TX MU channels followed by a list of phandles of
> +      RX MU channels. The number of expected tx and rx channels is 1 TX, and
> +      1 RX channels. All MU channels must be within the same MU instance.
> +      Cross instances are not allowed. The MU instance to be used is S4MUAP
> +      for imx8ulp & imx93. Users need to ensure that used MU instance does not
> +      conflict with other execution environments.
> +    items:
> +      - description: TX0 MU channel
> +      - description: RX0 MU channel
> +
> +  mbox-names:
> +    items:
> +      - const: tx
> +      - const: rx
> +
> +  fsl,mu-did:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      Owner of message-unit, is identified via Domain ID or did.

What is Domain ID?

> +
> +  fsl,mu-id:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      Identifier to the message-unit among the multiple message-unit that exists on SoC.
> +      It is used to create the channels, default to 2

Do you expect then multiple ele nodes in the DTS? What are these two
properties and why they are fixed per SoC, but still embedded in DTS?

> +
> +

Drop stray blank line.

> +required:
> +  - compatible
> +  - mboxes
> +  - mbox-names
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    ele_mu: ele_mu {

No underscores in node names, generic node names, e.g. firmware. Look at
existing code.

> +      compatible = "fsl,imx93-ele";
> +      mbox-names = "tx", "rx";
> +      mboxes = <&s4muap 2 0
> +                &s4muap 3 0>;

Two items, not one.

> +      fsl,mu-did = <1>;
> +      fsl,mu-id = <1>;
> +    };

Plus you clearly did not test the binding and DTS. You said you did some
internal review, so I assume this also includes some testing. How did
you test your DTS?

Best regards,
Krzysztof
Pankaj Gupta July 27, 2023, 9:20 a.m. UTC | #4
> -----Original Message-----
> From: Conor Dooley <conor.dooley@microchip.com>
> Sent: Monday, July 24, 2023 12:18 PM
> To: Pankaj Gupta <pankaj.gupta@nxp.com>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>; Conor Dooley
> <conor@kernel.org>; shawnguo@kernel.org; s.hauer@pengutronix.de;
> kernel@pengutronix.de; clin@suse.com; conor+dt@kernel.org;
> pierre.gondois@arm.com; Jacky Bai <ping.bai@nxp.com>; Clark Wang
> <xiaoning.wang@nxp.com>; Wei Fang <wei.fang@nxp.com>; Peng Fan
> <peng.fan@nxp.com>; Bough Chen <haibo.chen@nxp.com>;
> festevam@gmail.com; dl-linux-imx <linux-imx@nxp.com>;
> davem@davemloft.net; robh+dt@kernel.org;
> krzysztof.kozlowski+dt@linaro.org; linux-arm-kernel@lists.infradead.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Gaurav Jain
> <gaurav.jain@nxp.com>; alexander.stein@ew.tq-group.com; Sahil Malhotra
> <sahil.malhotra@nxp.com>; Aisheng Dong <aisheng.dong@nxp.com>; Varun
> Sethi <V.Sethi@nxp.com>
> Subject: Re: [EXT] Re: [PATCH v4 1/7] dt-bindings: arm: fsl: add se-fw binding
> doc
> 
> On Mon, Jul 24, 2023 at 06:37:22AM +0000, Pankaj Gupta wrote:
> > > From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> On
> > > 12/07/2023 20:26, Conor Dooley wrote:
> > > > On Wed, Jul 12, 2023 at 05:42:13PM +0530, Pankaj Gupta wrote:
> 
> > > >> +  value, i.e., supported SoC(s) are imx8ulp, imx93.
> 
> > > >> +
> > > >> +properties:
> > > >> +  compatible:
> > > >> +    enum:
> > > >> +      - fsl,imx-ele
> > > >
> > > > This looks like a generic compatible, not a specific one, but you
> > > > use it on the imx8ulp. I would have expected that you would have
> > > > something like "fsl,imx8ulp-ele" for that.
> > >
> > > Yeah, this one looks generic, so not what we expect.
> >
> > This change left un-changed in V4. It is "fsl,se-fw", instead of "fsl,imx8ulp-
> ele".
> > I will change in V5.

> 
> That's a generic compatible too, so no different to "fsl,imx-ele".
> What is the reason for avoiding the SoC-specific "fsl,imx8ulp-ele"?

Sorry. I missed this point.
Not trying to avoid the SoC specific compatible. I will add the soc id to make the compatible = "fsl,se-8ulpfw", instead of "fsl,se-fw".

Thanks for pointing out here.

> 
> > > >> +      - fsl,imx93-ele
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
new file mode 100644
index 000000000000..7567da0b4c21
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/freescale/fsl,se-fw.yaml
@@ -0,0 +1,121 @@ 
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/freescale/fsl,se-fw.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP i.MX EdgeLock Enclave Firmware (ELEFW)
+
+maintainers:
+  - Pankaj Gupta <pankaj.gupta@nxp.com>
+
+description: |
+
+  The NXP's i.MX EdgeLock Enclave, a HW IP creating an embedded
+  secure enclave within the SoC boundary to enable features like
+  - HSM
+  - SHE
+  - V2X
+
+  It uses message unit to communicate and coordinate to pass messages
+  (e.g., data,  status and control) through its interfaces.
+
+  This driver configures multiple misc-devices on the MU, to exchange
+  messages from User-space application and NXP's Edgelocke Enclave firmware.
+  The driver ensures that the messages must follow the following protocol
+  defined.
+
+                                     Non-Secure           +   Secure
+                                                          |
+                                                          |
+                   +---------+      +-------------+       |
+                   | ele_mu.c+<---->+imx-mailbox.c|       |
+                   |         |      |  mailbox.c  +<-->+------+    +------+
+                   +---+-----+      +-------------+    | MU X +<-->+ ELE |
+                       |                               +------+    +------+
+                       +----------------+                 |
+                       |                |                 |
+                       v                v                 |
+                   logical           logical              |
+                   receiver          waiter               |
+                      +                 +                 |
+                      |                 |                 |
+                      |                 |                 |
+                      |            +----+------+          |
+                      |            |           |          |
+                      |            |           |          |
+               device_ctx     device_ctx     device_ctx   |
+                                                          |
+                 User 0        User 1       User Y        |
+                 +------+      +------+     +------+      |
+                 |misc.c|      |misc.c|     |misc.c|      |
+  kernel space   +------+      +------+     +------+      |
+                                                          |
+  +------------------------------------------------------ |
+                     |             |           |          |
+  userspace     /dev/ele_muXch0    |           |          |
+                           /dev/ele_muXch1     |          |
+                                         /dev/ele_muXchY  |
+                                                          |
+
+  When a user sends a command to the ELE, it registers its device_ctx as
+  waiter of a response from ELE.
+
+  A user can be registered as receiver of command from the ELE.
+  Create char devices in /dev as channels of the form /dev/ele_muXchY with X
+  the id of the driver and Y for each users. It allows to send and receive
+  messages to the NXP EdgeLock Enclave IP on NXP SoC, where current possible
+  value, i.e., supported SoC(s) are imx8ulp, imx93.
+
+properties:
+  compatible:
+    enum:
+      - fsl,imx-ele
+      - fsl,imx93-ele
+
+  mboxes:
+    description:
+      A list of phandles of TX MU channels followed by a list of phandles of
+      RX MU channels. The number of expected tx and rx channels is 1 TX, and
+      1 RX channels. All MU channels must be within the same MU instance.
+      Cross instances are not allowed. The MU instance to be used is S4MUAP
+      for imx8ulp & imx93. Users need to ensure that used MU instance does not
+      conflict with other execution environments.
+    items:
+      - description: TX0 MU channel
+      - description: RX0 MU channel
+
+  mbox-names:
+    items:
+      - const: tx
+      - const: rx
+
+  fsl,mu-did:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Owner of message-unit, is identified via Domain ID or did.
+
+  fsl,mu-id:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Identifier to the message-unit among the multiple message-unit that exists on SoC.
+      It is used to create the channels, default to 2
+
+
+required:
+  - compatible
+  - mboxes
+  - mbox-names
+
+additionalProperties: false
+
+examples:
+  - |
+    ele_mu: ele_mu {
+      compatible = "fsl,imx93-ele";
+      mbox-names = "tx", "rx";
+      mboxes = <&s4muap 2 0
+                &s4muap 3 0>;
+      fsl,mu-did = <1>;
+      fsl,mu-id = <1>;
+    };