[PATCH] arm64: cpufeature: Export Armv8.6 Matrix feature to userspace

From: Julien Grall
Date: Fri Oct 25 2019 - 13:12:45 EST

This patch provides support for reporting the presence of Armv8.6
Matrix and its optional features to userspace.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

---

This based on [1] + commit ec52c7134b1f "arm64: cpufeature: Treat
ID_AA64ZFR0_EL1 as RAZ when SVE is not enabled" (taken from v5.4-rc4).

[1] arm64/for-next/elf-hwcap-docs
---
Documentation/arm64/cpu-feature-registers.rst | 8 ++++++++
Documentation/arm64/elf_hwcaps.rst | 15 +++++++++++++++
arch/arm64/include/asm/hwcap.h | 4 ++++
arch/arm64/include/asm/sysreg.h | 7 +++++++
arch/arm64/include/uapi/asm/hwcap.h | 4 ++++
arch/arm64/kernel/cpufeature.c | 11 +++++++++++
arch/arm64/kernel/cpuinfo.c | 4 ++++
7 files changed, 53 insertions(+)

diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst
index ffcf4e2c71ef..d1d6d56a7b08 100644
--- a/Documentation/arm64/cpu-feature-registers.rst
+++ b/Documentation/arm64/cpu-feature-registers.rst
@@ -193,6 +193,8 @@ infrastructure:
+------------------------------+---------+---------+
| Name | bits | visible |
+------------------------------+---------+---------+
+ | I8MM | [52-55] | y |
+ +------------------------------+---------+---------+
| SB | [36-39] | y |
+------------------------------+---------+---------+
| FRINTTS | [32-35] | y |
@@ -227,6 +229,12 @@ infrastructure:
+------------------------------+---------+---------+
| Name | bits | visible |
+------------------------------+---------+---------+
+ | F64MM | [56-59] | y |
+ +------------------------------+---------+---------+
+ | F32MM | [52-55] | y |
+ +------------------------------+---------+---------+
+ | I8MM | [44-47] | y |
+ +------------------------------+---------+---------+
| SM4 | [43-40] | y |
+------------------------------+---------+---------+
| SHA3 | [35-32] | y |
diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst
index 7fa3d215ae6a..b2bcc6868f4a 100644
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst
@@ -204,6 +204,21 @@ HWCAP2_FRINT

Functionality implied by ID_AA64ISAR1_EL1.FRINTTS == 0b0001.

+HWCAP2_SVEI8MM
+
+ Functionality implied by ID_AA64ZFR0_EL1.I8MM == 0b0001.
+
+HWCAP2_SVEF32MM
+
+ Functionality implied by ID_AA64ZFR0_EL1.F32MM == 0b0001.
+
+HWCAP2_SVEF64MM
+
+ Functionality implied by ID_AA64ZFR0_EL1.F64MM == 0b0001.
+
+HWCAP2_I8MM
+
+ Functionality implied by ID_AA64ISAR1_EL1.I8MM == 0b0001.

4. Unused AT_HWCAP bits
-----------------------
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 3d2f2472a36c..99dc0e08b4d3 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -86,6 +86,10 @@
#define KERNEL_HWCAP_SVESM4 __khwcap2_feature(SVESM4)
#define KERNEL_HWCAP_FLAGM2 __khwcap2_feature(FLAGM2)
#define KERNEL_HWCAP_FRINT __khwcap2_feature(FRINT)
+#define KERNEL_HWCAP_SVEI8MM __khwcap2_feature(SVEI8MM)
+#define KERNEL_HWCAP_SVEF32MM __khwcap2_feature(SVEF32MM)
+#define KERNEL_HWCAP_SVEF64MM __khwcap2_feature(SVEF64MM)
+#define KERNEL_HWCAP_I8MM __khwcap2_feature(I8MM)

/*
* This yields a mask that user programs can use to figure out what
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 972d196c7714..35b27a9620ef 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -553,6 +553,7 @@
#define ID_AA64ISAR0_AES_SHIFT 4

/* id_aa64isar1 */
+#define ID_AA64ISAR1_I8MM_SHIFT 52
#define ID_AA64ISAR1_SB_SHIFT 36
#define ID_AA64ISAR1_FRINTTS_SHIFT 32
#define ID_AA64ISAR1_GPI_SHIFT 28
@@ -605,12 +606,18 @@
#define ID_AA64PFR1_SSBS_PSTATE_INSNS 2

/* id_aa64zfr0 */
+#define ID_AA64ZFR0_F64MM_SHIFT 56
+#define ID_AA64ZFR0_F32MM_SHIFT 52
+#define ID_AA64ZFR0_I8MM_SHIFT 44
#define ID_AA64ZFR0_SM4_SHIFT 40
#define ID_AA64ZFR0_SHA3_SHIFT 32
#define ID_AA64ZFR0_BITPERM_SHIFT 16
#define ID_AA64ZFR0_AES_SHIFT 4
#define ID_AA64ZFR0_SVEVER_SHIFT 0

+#define ID_AA64ZFR0_F64MM 0x1
+#define ID_AA64ZFR0_F32MM 0x1
+#define ID_AA64ZFR0_I8MM 0x1
#define ID_AA64ZFR0_SM4 0x1
#define ID_AA64ZFR0_SHA3 0x1
#define ID_AA64ZFR0_BITPERM 0x1
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h
index a1e72886b30c..10f207b81091 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -65,5 +65,9 @@
#define HWCAP2_SVESM4 (1 << 6)
#define HWCAP2_FLAGM2 (1 << 7)
#define HWCAP2_FRINT (1 << 8)
+#define HWCAP2_SVEI8MM (1 << 9)
+#define HWCAP2_SVEF32MM (1 << 10)
+#define HWCAP2_SVEF64MM (1 << 11)
+#define HWCAP2_I8MM (1 << 12)

#endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 80f459ad0190..6d196c66f80d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -135,6 +135,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
};

static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_I8MM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FRINTTS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
@@ -177,6 +178,12 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {

static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
+ FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F64MM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
+ FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_F32MM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
+ FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_I8MM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
@@ -1650,6 +1657,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
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_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
#ifdef CONFIG_ARM64_SVE
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
@@ -1659,6 +1667,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
+ HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_I8MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_I8MM, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM),
+ HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F32MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F32MM, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM),
+ HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM),
#endif
HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
#ifdef CONFIG_ARM64_PTR_AUTH
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 05933c065732..ae76c794bd09 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -84,6 +84,10 @@ static const char *const hwcap_str[] = {
"svesm4",
"flagm2",
"frint",
+ "svei8mm",
+ "svef32mm",
+ "svef64mm",
+ "i8mm",
NULL
};

--
2.11.0