[PATCH 2/3] arm64: v8.3: Support for complex number instructions

[Suzuki K Poulose]

ARM v8.3 adds support for new instructions to aid floating-point
multiplication and addition of complex numbers. Expose the support
via HWCAP and MRS emulation

Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
---
 Documentation/arm64/cpu-feature-registers.txt | 2 ++
 arch/arm64/include/asm/sysreg.h               | 1 +
 arch/arm64/include/uapi/asm/hwcap.h           | 1 +
 arch/arm64/kernel/cpufeature.c                | 2 ++
 arch/arm64/kernel/cpuinfo.c                   | 1 +
 5 files changed, 7 insertions(+)

diff --git a/Documentation/arm64/cpu-feature-registers.txt b/Documentation/arm64/cpu-feature-registers.txt
index 5b279dc..0ce0a40 100644
--- a/Documentation/arm64/cpu-feature-registers.txt
+++ b/Documentation/arm64/cpu-feature-registers.txt
@@ -174,6 +174,8 @@ infrastructure:
      x--------------------------------------------------x
      | Name                         |  bits   | visible |
      |--------------------------------------------------|
+     | FCMA                         | [19-16] |    y    |
+     |--------------------------------------------------|
      | JSCVT                        | [15-12] |    y    |
      x--------------------------------------------------x
 
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index cbb3143..69af995 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -157,6 +157,7 @@
 #define ID_AA64ISAR0_AES_SHIFT		4
 
 /* id_aa64isar1 */
+#define ID_AA64ISAR1_FCMA_SHIFT		16
 #define ID_AA64ISAR1_JSCVT_SHIFT	12
 
 /* id_aa64pfr0 */
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h
index 391a876..85841a4 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -33,5 +33,6 @@
 #define HWCAP_CPUID		(1 << 11)
 #define HWCAP_ASIMDRDM		(1 << 12)
 #define HWCAP_JSCVT		(1 << 13)
+#define HWCAP_FCMA		(1 << 14)
 
 #endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index af88910..a5ff8ae 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -98,6 +98,7 @@ 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_EXACT, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
 	ARM64_FTR_END,
 };
@@ -894,6 +895,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, HWCAP_ASIMD),
 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, HWCAP_ASIMDHP),
 	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_JSCVT),
+	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_FCMA),
 	{},
 };
 
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 95cfd33..e6afed8 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -66,6 +66,7 @@ static const char *const hwcap_str[] = {
 	"cpuid",
 	"asimdrdm",
 	"jscvt",
+	"fcma",
 	NULL
 };
 
-- 
2.7.4