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authorKristina Martsenko <kristina.martsenko@arm.com>2023-09-12 14:34:29 +0100
committerWill Deacon <will@kernel.org>2023-09-18 10:45:11 +0100
commit479965a2b7ec481737df0cadf553331063b9c343 (patch)
tree8d67f1b86187a7acc9e70faec6a0477bb059e63d
parent215b215d1e9278765c32af29515e8cdf679d47a3 (diff)
downloadlwn-479965a2b7ec481737df0cadf553331063b9c343.tar.gz
lwn-479965a2b7ec481737df0cadf553331063b9c343.zip
arm64: cpufeature: Fix CLRBHB and BC detection
ClearBHB support is indicated by the CLRBHB field in ID_AA64ISAR2_EL1. Following some refactoring the kernel incorrectly checks the BC field instead. Fix the detection to use the right field. (Note: The original ClearBHB support had it as FTR_HIGHER_SAFE, but this patch uses FTR_LOWER_SAFE, which seems more correct.) Also fix the detection of BC (hinted conditional branches) to use FTR_LOWER_SAFE, so that it is not reported on mismatched systems. Fixes: 356137e68a9f ("arm64/sysreg: Make BHB clear feature defines match the architecture") Fixes: 8fcc8285c0e3 ("arm64/sysreg: Convert ID_AA64ISAR2_EL1 to automatic generation") Cc: stable@vger.kernel.org Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20230912133429.2606875-1-kristina.martsenko@arm.com Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r--arch/arm64/include/asm/cpufeature.h2
-rw-r--r--arch/arm64/kernel/cpufeature.c3
-rw-r--r--arch/arm64/tools/sysreg6
3 files changed, 8 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 96e50227f940..5bba39376055 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -663,7 +663,7 @@ static inline bool supports_clearbhb(int scope)
isar2 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
return cpuid_feature_extract_unsigned_field(isar2,
- ID_AA64ISAR2_EL1_BC_SHIFT);
+ ID_AA64ISAR2_EL1_CLRBHB_SHIFT);
}
const struct cpumask *system_32bit_el0_cpumask(void);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index b018ae12ff5f..444a73c2e638 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -222,7 +222,8 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CLRBHB_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_MOPS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
FTR_STRICT, FTR_EXACT, ID_AA64ISAR2_EL1_APA3_SHIFT, 4, 0),
diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
index 2517ef7c21cf..76ce150e7347 100644
--- a/arch/arm64/tools/sysreg
+++ b/arch/arm64/tools/sysreg
@@ -1347,7 +1347,11 @@ UnsignedEnum 51:48 RPRFM
0b0000 NI
0b0001 IMP
EndEnum
-Res0 47:28
+Res0 47:32
+UnsignedEnum 31:28 CLRBHB
+ 0b0000 NI
+ 0b0001 IMP
+EndEnum
UnsignedEnum 27:24 PAC_frac
0b0000 NI
0b0001 IMP