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[6/8] ARM: vfp: Add hwcap for FEAT_AA32I8MM

Message ID 20221026055001.12986-7-amit.kachhap@arm.com (mailing list archive)
State New, archived
Headers show
Series ARM: Expose Armv8 AArch32 features via hwcap | expand

Commit Message

Amit Daniel Kachhap Oct. 26, 2022, 5:49 a.m. UTC 
Int8 matrix multiplication (FEAT_AA32I8MM) is a feature present in AArch32
state for Armv8 and is represented by ISAR6.I8MM identification register.

This feature denotes the presence of VSMMLA, VSUDOT, VUMMLA, VUSMMLA and
VUSDOT instructions and hence adding a hwcap will enable the userspace
to check it before trying to use those instructions.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 arch/arm/include/uapi/asm/hwcap.h | 1 +
 arch/arm/kernel/setup.c           | 1 +
 arch/arm/vfp/vfpmodule.c          | 6 ++++++
 3 files changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm/include/uapi/asm/hwcap.h b/arch/arm/include/uapi/asm/hwcap.h
index 14e260e2d6d0..46833c668ec2 100644
--- a/arch/arm/include/uapi/asm/hwcap.h
+++ b/arch/arm/include/uapi/asm/hwcap.h
@@ -33,6 +33,7 @@ 
 #define HWCAP_ASIMDDP	(1 << 24)
 #define HWCAP_ASIMDFHM	(1 << 25)
 #define HWCAP_ASIMDBF16	(1 << 26)
+#define HWCAP_I8MM	(1 << 27)
 
 /*
  * HWCAP2 flags - for elf_hwcap2 (in kernel) and AT_HWCAP2
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 231d885ad4b5..de2d85ddec8d 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1254,6 +1254,7 @@  static const char *hwcap_str[] = {
 	"asimddp",
 	"asimdfhm",
 	"asimdbf16",
+	"i8mm",
 	NULL
 };
 
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index ff574cb8a0b9..281110423871 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -857,6 +857,12 @@  static int __init vfp_init(void)
 		 */
 		if (cpuid_feature_extract_field(isar6, 20) == 0x1)
 			elf_hwcap |= HWCAP_ASIMDBF16;
+		/*
+		 * Check for the presence of Advanced SIMD and floating point
+		 * Int8 matrix multiplication instructions instructions.
+		 */
+		if (cpuid_feature_extract_field(isar6, 24) == 0x1)
+			elf_hwcap |= HWCAP_I8MM;
 
 	/* Extract the architecture version on pre-cpuid scheme */
 	} else {