This is a note to let you know that I've just added the patch titled
arm64: add HWCAP for FEAT_HBC (hinted conditional branches)
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-add-hwcap-for-feat_hbc-hinted-conditional-bran.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8057be5d7ac578722af942d2455258d2e2e07944
Author: Joey Gouly <joey.gouly@xxxxxxx>
Date: Fri Aug 4 15:37:45 2023 +0100
arm64: add HWCAP for FEAT_HBC (hinted conditional branches)
[ Upstream commit 7f86d128e437990fd08d9e66ae7c1571666cff8a ]
Add a HWCAP for FEAT_HBC, so that userspace can make a decision on using
this feature.
Signed-off-by: Joey Gouly <joey.gouly@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230804143746.3900803-2-joey.gouly@xxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Stable-dep-of: 479965a2b7ec ("arm64: cpufeature: Fix CLRBHB and BC detection")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 692b1ec663b27..521267478d187 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -138,6 +138,7 @@
#define KERNEL_HWCAP_SME_B16B16 __khwcap2_feature(SME_B16B16)
#define KERNEL_HWCAP_SME_F16F16 __khwcap2_feature(SME_F16F16)
#define KERNEL_HWCAP_MOPS __khwcap2_feature(MOPS)
+#define KERNEL_HWCAP_HBC __khwcap2_feature(HBC)
/*
* This yields a mask that user programs can use to figure out what
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h
index a2cac4305b1e0..53026f45a5092 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -103,5 +103,6 @@
#define HWCAP2_SME_B16B16 (1UL << 41)
#define HWCAP2_SME_F16F16 (1UL << 42)
#define HWCAP2_MOPS (1UL << 43)
+#define HWCAP2_HBC (1UL << 44)
#endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index f9d456fe132d8..ac764c1dac363 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -222,7 +222,7 @@ 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_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_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),
@@ -2844,6 +2844,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(ID_AA64ISAR2_EL1, RPRES, IMP, CAP_HWCAP, KERNEL_HWCAP_RPRES),
HWCAP_CAP(ID_AA64ISAR2_EL1, WFxT, IMP, CAP_HWCAP, KERNEL_HWCAP_WFXT),
HWCAP_CAP(ID_AA64ISAR2_EL1, MOPS, IMP, CAP_HWCAP, KERNEL_HWCAP_MOPS),
+ HWCAP_CAP(ID_AA64ISAR2_EL1, BC, IMP, CAP_HWCAP, KERNEL_HWCAP_HBC),
#ifdef CONFIG_ARM64_SME
HWCAP_CAP(ID_AA64PFR1_EL1, SME, IMP, CAP_HWCAP, KERNEL_HWCAP_SME),
HWCAP_CAP(ID_AA64SMFR0_EL1, FA64, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_FA64),
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 58622dc859177..98fda85005353 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -126,6 +126,7 @@ static const char *const hwcap_str[] = {
[KERNEL_HWCAP_SME_B16B16] = "smeb16b16",
[KERNEL_HWCAP_SME_F16F16] = "smef16f16",
[KERNEL_HWCAP_MOPS] = "mops",
+ [KERNEL_HWCAP_HBC] = "hbc",
};
#ifdef CONFIG_COMPAT
