arm64/hwcap: Add support for FEAT_CSSC

FEAT_CSSC adds a number of new instructions usable to optimise common short
sequences of instructions, add a hwcap indicating that the feature is
available and can be used by userspace.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20221017152520.1039165-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Mark Brown 2022-10-17 16:25:15 +01:00 committed by Will Deacon
parent 01ab991fc0
commit 95aa6860d6
6 changed files with 14 additions and 1 deletions

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@ -275,6 +275,9 @@ HWCAP2_EBF16
HWCAP2_SVE_EBF16
Functionality implied by ID_AA64ZFR0_EL1.BF16 == 0b0010.
HWCAP2_CSSC
Functionality implied by ID_AA64ISAR2_EL1.CSSC == 0b0001.
4. Unused AT_HWCAP bits
-----------------------

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@ -120,6 +120,7 @@
#define KERNEL_HWCAP_WFXT __khwcap2_feature(WFXT)
#define KERNEL_HWCAP_EBF16 __khwcap2_feature(EBF16)
#define KERNEL_HWCAP_SVE_EBF16 __khwcap2_feature(SVE_EBF16)
#define KERNEL_HWCAP_CSSC __khwcap2_feature(CSSC)
/*
* This yields a mask that user programs can use to figure out what

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@ -93,5 +93,6 @@
#define HWCAP2_WFXT (1UL << 31)
#define HWCAP2_EBF16 (1UL << 32)
#define HWCAP2_SVE_EBF16 (1UL << 33)
#define HWCAP2_CSSC (1UL << 34)
#endif /* _UAPI__ASM_HWCAP_H */

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@ -212,6 +212,7 @@ 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_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_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),
@ -2815,6 +2816,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
#endif /* CONFIG_ARM64_MTE */
HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_EL1_ECV_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV),
HWCAP_CAP(SYS_ID_AA64MMFR1_EL1, ID_AA64MMFR1_EL1_AFP_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AFP),
HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_EL1_CSSC_IMP, CAP_HWCAP, KERNEL_HWCAP_CSSC),
HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_RPRES_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RPRES),
HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_WFxT_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_EL1_WFxT_IMP, CAP_HWCAP, KERNEL_HWCAP_WFXT),
#ifdef CONFIG_ARM64_SME

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@ -116,6 +116,7 @@ static const char *const hwcap_str[] = {
[KERNEL_HWCAP_WFXT] = "wfxt",
[KERNEL_HWCAP_EBF16] = "ebf16",
[KERNEL_HWCAP_SVE_EBF16] = "sveebf16",
[KERNEL_HWCAP_CSSC] = "cssc",
};
#ifdef CONFIG_COMPAT

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@ -484,7 +484,12 @@ EndEnum
EndSysreg
Sysreg ID_AA64ISAR2_EL1 3 0 0 6 2
Res0 63:28
Res0 63:56
Enum 55:52 CSSC
0b0000 NI
0b0001 IMP
EndEnum
Res0 51:28
Enum 27:24 PAC_frac
0b0000 NI
0b0001 IMP