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| author | Yee Lee <yee.lee@mediatek.com> | 2021-08-03 10:08:22 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2021-08-03 17:48:01 +0300 |
| commit | 7a062ce31807eb402c38edbec50c1b848b4298f3 (patch) | |
| tree | 0844ecbf2b1562746161775040c28fbe3cc00683 /arch/arm64/kernel | |
| parent | 767215030150d9d01ff65fbc1c5dff515ffdcfe3 (diff) | |
| download | linux-7a062ce31807eb402c38edbec50c1b848b4298f3.tar.xz | |
arm64/cpufeature: Optionally disable MTE via command-line
MTE support needs to be optionally disabled in runtime
for HW issue workaround, FW development and some
evaluation works on system resource and performance.
This patch makes two changes:
(1) moves init of tag-allocation bits(ATA/ATA0) to
cpu_enable_mte() as not cached in TLB.
(2) allows ID_AA64PFR1_EL1.MTE to be overridden on
its shadow value by giving "arm64.nomte" on cmdline.
When the feature value is off, ATA and TCF will not set
and the related functionalities are accordingly suppressed.
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Marc Zyngier <maz@kernel.org>
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
Link: https://lore.kernel.org/r/20210803070824.7586-2-yee.lee@mediatek.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/idreg-override.c | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 0ead8bfedf20..51e6bf4bb7b5 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1843,6 +1843,9 @@ static void bti_enable(const struct arm64_cpu_capabilities *__unused) #ifdef CONFIG_ARM64_MTE static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) { + sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0); + isb(); + /* * Clear the tags in the zero page. This needs to be done via the * linear map which has the Tagged attribute. diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index 53a381a7f65d..d8e606fe3c21 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -54,6 +54,7 @@ static const struct ftr_set_desc pfr1 __initconst = { .override = &id_aa64pfr1_override, .fields = { { "bt", ID_AA64PFR1_BT_SHIFT }, + { "mte", ID_AA64PFR1_MTE_SHIFT}, {} }, }; @@ -100,6 +101,7 @@ static const struct { { "arm64.nopauth", "id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 " "id_aa64isar1.api=0 id_aa64isar1.apa=0" }, + { "arm64.nomte", "id_aa64pfr1.mte=0" }, { "nokaslr", "kaslr.disabled=1" }, }; |