On Thu, Mar 07, 2024 at 09:41:31PM +1100, Michael Ellerman wrote:
Stefan Berger <stefanb@xxxxxxxxxxxxx> writes:
linux,sml-base holds the address of a buffer with the TPM log. This
buffer may become invalid after a kexec and therefore embed the whole TPM
log in linux,sml-log. This helps to protect the log since it is properly
carried across a kexec with both of the kexec syscalls.
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
---
arch/powerpc/kernel/prom_init.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
Also adding the new linux,sml-log property should be accompanied by a
change to the device tree binding.
The syntax is not very obvious to me, but possibly something like?
diff --git a/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml b/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
index 50a3fd31241c..cd75037948bc 100644
--- a/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
+++ b/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
@@ -74,8 +74,6 @@ required:
- ibm,my-dma-window
- ibm,my-drc-index
- ibm,loc-code
- - linux,sml-base
- - linux,sml-size
Dropping required properties is an ABI break. If you drop them, an older
OS version won't work.
allOf:
- $ref: tpm-common.yaml#
diff --git a/Documentation/devicetree/bindings/tpm/tpm-common.yaml b/Documentation/devicetree/bindings/tpm/tpm-common.yaml
index 3c1241b2a43f..616604707c95 100644
--- a/Documentation/devicetree/bindings/tpm/tpm-common.yaml
+++ b/Documentation/devicetree/bindings/tpm/tpm-common.yaml
@@ -25,6 +25,11 @@ properties:
base address of reserved memory allocated for firmware event log
$ref: /schemas/types.yaml#/definitions/uint64
+ linux,sml-log:
Why is this Linux specific?