Messages in this thread Patch in this message | | | From | Kristina Martsenko <> | Subject | [PATCH v2 10/11] arm64: mops: allow disabling MOPS from the kernel command line | Date | Tue, 9 May 2023 15:22:34 +0100 |
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Make it possible to disable the MOPS extension at runtime using the kernel command line. This can be useful for testing or working around hardware issues. For example it could be used to test new memory copy routines that do not use MOPS instructions (e.g. from Arm Optimized Routines).
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/arm64/kernel/idreg-override.c | 2 ++ 2 files changed, 5 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9e5bab29685f..e01fbfd78ae9 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -429,6 +429,9 @@ arm64.nosme [ARM64] Unconditionally disable Scalable Matrix Extension support + arm64.nomops [ARM64] Unconditionally disable Memory Copy and Memory + Set instructions support + ataflop= [HW,M68k] atarimouse= [HW,MOUSE] Atari Mouse diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index 370ab84fd06e..8439248c21d3 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -123,6 +123,7 @@ static const struct ftr_set_desc isar2 __initconst = { .fields = { FIELD("gpa3", ID_AA64ISAR2_EL1_GPA3_SHIFT, NULL), FIELD("apa3", ID_AA64ISAR2_EL1_APA3_SHIFT, NULL), + FIELD("mops", ID_AA64ISAR2_EL1_MOPS_SHIFT, NULL), {} }, }; @@ -174,6 +175,7 @@ static const struct { "id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 " "id_aa64isar1.api=0 id_aa64isar1.apa=0 " "id_aa64isar2.gpa3=0 id_aa64isar2.apa3=0" }, + { "arm64.nomops", "id_aa64isar2.mops=0" }, { "arm64.nomte", "id_aa64pfr1.mte=0" }, { "nokaslr", "kaslr.disabled=1" }, }; -- 2.25.1
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