arm64/hwcap: Add support for SVE 2.1

FEAT_SVE2p1 introduces a number of new SVE instructions. Since there is no
new architectural state added kernel support is simply a new hwcap which
lets userspace know that the feature is supported.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20221017152520.1039165-6-broonie@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>

Documentation/arm64/elf_hwcaps.rst

@@ -281,6 +281,9 @@ HWCAP2_CSSC
 HWCAP2_RPRFM
     Functionality implied by ID_AA64ISAR2_EL1.RPRFM == 0b0001.
 
+HWCAP2_SVE2P1
+    Functionality implied by ID_AA64ZFR0_EL1.SVEver == 0b0010.
+
 4. Unused AT_HWCAP bits
 -----------------------
 

Documentation/arm64/sve.rst

@@ -52,6 +52,7 @@ model features for SVE is included in Appendix A.
 	HWCAP2_SVEBITPERM
 	HWCAP2_SVESHA3
 	HWCAP2_SVESM4
+	HWCAP2_SVE2P1
 
   This list may be extended over time as the SVE architecture evolves.
 

arch/arm64/include/asm/hwcap.h

@@ -122,6 +122,7 @@
 #define KERNEL_HWCAP_SVE_EBF16		__khwcap2_feature(SVE_EBF16)
 #define KERNEL_HWCAP_CSSC		__khwcap2_feature(CSSC)
 #define KERNEL_HWCAP_RPRFM		__khwcap2_feature(RPRFM)
+#define KERNEL_HWCAP_SVE2P1		__khwcap2_feature(SVE2P1)
 
 /*
  * This yields a mask that user programs can use to figure out what

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

@@ -95,5 +95,6 @@
 #define HWCAP2_SVE_EBF16	(1UL << 33)
 #define HWCAP2_CSSC		(1UL << 34)
 #define HWCAP2_RPRFM		(1UL << 35)
+#define HWCAP2_SVE2P1		(1UL << 36)
 
 #endif /* _UAPI__ASM_HWCAP_H */

arch/arm64/kernel/cpufeature.c

@@ -2791,6 +2791,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_EL1_AT_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
 #ifdef CONFIG_ARM64_SVE
 	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_EL1_SVE_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR0_EL1_SVE_IMP, CAP_HWCAP, KERNEL_HWCAP_SVE),
+	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_SVEver_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_SVEver_SVE2p1, CAP_HWCAP, KERNEL_HWCAP_SVE2P1),
 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_SVEver_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_SVEver_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_AES_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_AES_IMP, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_EL1_AES_SHIFT, 4, FTR_UNSIGNED, ID_AA64ZFR0_EL1_AES_PMULL128, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),

arch/arm64/kernel/cpuinfo.c

@@ -118,6 +118,7 @@ static const char *const hwcap_str[] = {
 	[KERNEL_HWCAP_SVE_EBF16]	= "sveebf16",
 	[KERNEL_HWCAP_CSSC]		= "cssc",
 	[KERNEL_HWCAP_RPRFM]		= "rprfm",
+	[KERNEL_HWCAP_SVE2P1]		= "sve2p1",
 };
 
 #ifdef CONFIG_COMPAT

arch/arm64/tools/sysreg

@@ -210,6 +210,7 @@ EndEnum
 Enum	3:0	SVEver
 	0b0000	IMP
 	0b0001	SVE2
+	0b0010	SVE2p1
 EndEnum
 EndSysreg