On 8/15/22 14:30, Mark Brown wrote:
In order to allow debuggers to discover lazily saved SME state we need
to provide access to TPIDR2_EL0, we will extend the existing NT_ARM_TLS
used for TPIDR to also include TPIDR2_EL0 as the second register in the
regset.
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
Documentation/arm64/sme.rst | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/arm64/sme.rst b/Documentation/arm64/sme.rst
index 937147f58cc5..16d2db4c2e2e 100644
--- a/Documentation/arm64/sme.rst
+++ b/Documentation/arm64/sme.rst
@@ -331,6 +331,9 @@ The regset data starts with struct user_za_header, containing:
been read if a PTRACE_GETREGSET of NT_ARM_ZA were executed for each thread
when the coredump was generated.
+* The NT_ARM_TLS note will be extended to two registers, the second register
+ will contain TPIDR2_EL0 on systems that support SME and will be read as
+ zero with writes ignored otherwise.
9. System runtime configuration
--------------------------------
I wonder if we should document a bit more about the use of TPIDR2, its states, values and
block format when TPIDR2 points to valid ZA state.
Would that make sense?
