From 1201937491822b61641c1878ebcd16a93aed4540 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@kernel.org>
Date: Tue, 18 Jun 2019 19:10:54 +0100
Subject: [PATCH] arm64: Expose ARMv8.5 CondM capability to userspace
ARMv8.5 adds new instructions XAFLAG and AXFLAG to translate the
representation of the results of floating point comparisons between the
native ARM format and an alternative format used by some software. Add
a hwcap allowing userspace to determine if they are present, since we
referred to earlier CondM extensions as FLAGM call these extensions
FLAGM2.
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>
---
Documentation/arm64/elf_hwcaps.txt | 4 ++++
arch/arm64/include/asm/hwcap.h | 1 +
arch/arm64/include/uapi/asm/hwcap.h | 1 +
arch/arm64/kernel/cpufeature.c | 1 +
arch/arm64/kernel/cpuinfo.c | 1 +
5 files changed, 8 insertions(+)
diff --git a/Documentation/arm64/elf_hwcaps.txt b/Documentation/arm64/elf_hwcaps.txt
index b73a2519ecf23..ee8dbfe652b63 100644
--- a/Documentation/arm64/elf_hwcaps.txt
+++ b/Documentation/arm64/elf_hwcaps.txt
@@ -207,6 +207,10 @@ HWCAP_FLAGM
Functionality implied by ID_AA64ISAR0_EL1.TS == 0b0001.
+HWCAP2_FLAGM2
+
+ Functionality implied by ID_AA64ISAR0_EL1.TS == 0b0010.
+
HWCAP_SSBS
Functionality implied by ID_AA64PFR1_EL1.SSBS == 0b0010.
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index b4bfb6672168b..838c47f903893 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -95,6 +95,7 @@
#define KERNEL_HWCAP_SVEBITPERM __khwcap2_feature(SVEBITPERM)
#define KERNEL_HWCAP_SVESHA3 __khwcap2_feature(SVESHA3)
#define KERNEL_HWCAP_SVESM4 __khwcap2_feature(SVESM4)
+#define KERNEL_HWCAP_FLAGM2 __khwcap2_feature(FLAGM2)
/*
* 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 1a772b162191a..7902ae4f38b43 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -63,5 +63,6 @@
#define HWCAP2_SVEBITPERM (1 << 4)
#define HWCAP2_SVESHA3 (1 << 5)
#define HWCAP2_SVESM4 (1 << 6)
+#define HWCAP2_FLAGM2 (1 << 7)
#endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2a7159fda3ce4..8350016dbb28d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1628,6 +1628,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
+ HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index f6f7936be6e7f..62102f75dc1e9 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -92,6 +92,7 @@ static const char *const hwcap_str[] = {
"svebitperm",
"svesha3",
"svesm4",
+ "flagm2",
NULL
};
--
2.30.2