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@kernel.org
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?