Commit eefc9871 authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

arm64/hwcap: Add hwcap for GCS 



Provide a hwcap to enable userspace to detect support for GCS.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Acked-by: default avatarYury Khrustalev <yury.khrustalev@arm.com>
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-18-222b78d87eee@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent a9445211

Documentation/arch/arm64/elf_hwcaps.rst

+4 −0
Original line number Diff line number Diff line
@@ -170,6 +170,10 @@ HWCAP_PACG 
    ID_AA64ISAR1_EL1.GPI == 0b0001, as described by

    Documentation/arch/arm64/pointer-authentication.rst.



HWCAP_GCS

    Functionality implied by ID_AA64PFR1_EL1.GCS == 0b1, as

    described by Documentation/arch/arm64/gcs.rst.



HWCAP2_DCPODP

    Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0010.

arch/arm64/include/asm/hwcap.h

+1 −0
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ 
#define KERNEL_HWCAP_SB			__khwcap_feature(SB)

#define KERNEL_HWCAP_PACA		__khwcap_feature(PACA)

#define KERNEL_HWCAP_PACG		__khwcap_feature(PACG)

#define KERNEL_HWCAP_GCS		__khwcap_feature(GCS)



#define __khwcap2_feature(x)		(const_ilog2(HWCAP2_ ## x) + 64)

#define KERNEL_HWCAP_DCPODP		__khwcap2_feature(DCPODP)

arch/arm64/include/uapi/asm/hwcap.h

+2 −1
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
 * HWCAP flags - for AT_HWCAP

 *

 * Bits 62 and 63 are reserved for use by libc.

 * Bits 32-61 are unallocated for potential use by libc.

 * Bits 33-61 are unallocated for potential use by libc.

 */

#define HWCAP_FP		(1 << 0)

#define HWCAP_ASIMD		(1 << 1)
@@ -55,6 +55,7 @@ 
#define HWCAP_SB		(1 << 29)

#define HWCAP_PACA		(1 << 30)

#define HWCAP_PACG		(1UL << 31)

#define HWCAP_GCS		(1UL << 32)



/*

 * HWCAP2 flags - for AT_HWCAP2

arch/arm64/kernel/cpufeature.c

+3 −0
Original line number Diff line number Diff line
@@ -3025,6 +3025,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { 
	HWCAP_CAP(ID_AA64ZFR0_EL1, I8MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),

	HWCAP_CAP(ID_AA64ZFR0_EL1, F32MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),

	HWCAP_CAP(ID_AA64ZFR0_EL1, F64MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),

#endif

#ifdef CONFIG_ARM64_GCS

	HWCAP_CAP(ID_AA64PFR1_EL1, GCS, IMP, CAP_HWCAP, KERNEL_HWCAP_GCS),

#endif

	HWCAP_CAP(ID_AA64PFR1_EL1, SSBS, SSBS2, CAP_HWCAP, KERNEL_HWCAP_SSBS),

#ifdef CONFIG_ARM64_BTI

arch/arm64/kernel/cpuinfo.c

+1 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ static const char *const hwcap_str[] = { 
	[KERNEL_HWCAP_SB]		= "sb",

	[KERNEL_HWCAP_PACA]		= "paca",

	[KERNEL_HWCAP_PACG]		= "pacg",

	[KERNEL_HWCAP_GCS]		= "gcs",

	[KERNEL_HWCAP_DCPODP]		= "dcpodp",

	[KERNEL_HWCAP_SVE2]		= "sve2",

	[KERNEL_HWCAP_SVEAES]		= "sveaes",