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arm64: Expose FRINT capabilities to userspace

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ARMv8.5 introduces the FRINT series of instructions for rounding floating
point numbers to integers. Provide a capability to userspace in order to
allow applications to determine if the system supports these instructions.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Brown 2019-06-18 19:10:55 +01:00 committed by Catalin Marinas
parent 1201937491
commit ca9503fc9e
6 changed files with 9 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
Documentation/arm64/elf_hwcaps.txt
View file

@ -227,6 +227,10 @@ HWCAP_PACG
ID_AA64ISAR1_EL1.GPI == 0b0001, as described by
Documentation/arm64/pointer-authentication.txt.
HWCAP2_FRINT
Functionality implied by ID_AA64ISAR1_EL1.FRINTTS == 0b0001.
4. Unused AT_HWCAP bits
-----------------------

1
arch/arm64/include/asm/hwcap.h
View file

@ -96,6 +96,7 @@
#define KERNEL_HWCAP_SVESHA3 __khwcap2_feature(SVESHA3)
#define KERNEL_HWCAP_SVESM4 __khwcap2_feature(SVESM4)
#define KERNEL_HWCAP_FLAGM2 __khwcap2_feature(FLAGM2)
#define KERNEL_HWCAP_FRINT __khwcap2_feature(FRINT)
/*
* This yields a mask that user programs can use to figure out what

1
arch/arm64/include/asm/sysreg.h
View file

@ -560,6 +560,7 @@
/* id_aa64isar1 */
#define ID_AA64ISAR1_SB_SHIFT 36
#define ID_AA64ISAR1_FRINTTS_SHIFT 32
#define ID_AA64ISAR1_GPI_SHIFT 28
#define ID_AA64ISAR1_GPA_SHIFT 24
#define ID_AA64ISAR1_LRCPC_SHIFT 20

1
arch/arm64/include/uapi/asm/hwcap.h
View file

@ -64,5 +64,6 @@
#define HWCAP2_SVESHA3 (1 << 5)
#define HWCAP2_SVESM4 (1 << 6)
#define HWCAP2_FLAGM2 (1 << 7)
#define HWCAP2_FRINT (1 << 8)
#endif /* _UAPI__ASM_HWCAP_H */

1
arch/arm64/kernel/cpufeature.c
View file

@ -1640,6 +1640,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
#ifdef CONFIG_ARM64_SVE

1
arch/arm64/kernel/cpuinfo.c
View file

@ -93,6 +93,7 @@ static const char *const hwcap_str[] = {
"svesha3",
"svesm4",
"flagm2",
"frint",
NULL
};