Merge branch 'for-next/feat_lrcpc3' into for-next/core

* for-next/feat_lrcpc3:
  : HWCAP for FEAT_LRCPC3
  selftests/arm64: add HWCAP2_LRCPC3 test
  arm64: add FEAT_LRCPC3 HWCAP

Author: ctmarinas

Documentation/arch/arm64/elf_hwcaps.rst

@@ -311,6 +311,9 @@ HWCAP2_HBC
 HWCAP2_SVE_B16B16
     Functionality implied by ID_AA64ZFR0_EL1.B16B16 == 0b0001.
 
+HWCAP2_LRCPC3
+    Functionality implied by ID_AA64ISAR1_EL1.LRCPC == 0b0011.
+
 4. Unused AT_HWCAP bits
 -----------------------
 

arch/arm64/include/asm/hwcap.h

@@ -140,6 +140,7 @@
 #define KERNEL_HWCAP_MOPS		__khwcap2_feature(MOPS)
 #define KERNEL_HWCAP_HBC		__khwcap2_feature(HBC)
 #define KERNEL_HWCAP_SVE_B16B16		__khwcap2_feature(SVE_B16B16)
+#define KERNEL_HWCAP_LRCPC3		__khwcap2_feature(LRCPC3)
 
 /*
  * This yields a mask that user programs can use to figure out what

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

@@ -105,5 +105,6 @@
 #define HWCAP2_MOPS		(1UL << 43)
 #define HWCAP2_HBC		(1UL << 44)
 #define HWCAP2_SVE_B16B16	(1UL << 45)
+#define HWCAP2_LRCPC3		(1UL << 46)
 
 #endif /* _UAPI__ASM_HWCAP_H */

arch/arm64/kernel/cpufeature.c

@@ -2766,6 +2766,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(ID_AA64ISAR1_EL1, FCMA, IMP, CAP_HWCAP, KERNEL_HWCAP_FCMA),
 	HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, IMP, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
 	HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, LRCPC2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
+	HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, LRCPC3, CAP_HWCAP, KERNEL_HWCAP_LRCPC3),
 	HWCAP_CAP(ID_AA64ISAR1_EL1, FRINTTS, IMP, CAP_HWCAP, KERNEL_HWCAP_FRINT),
 	HWCAP_CAP(ID_AA64ISAR1_EL1, SB, IMP, CAP_HWCAP, KERNEL_HWCAP_SB),
 	HWCAP_CAP(ID_AA64ISAR1_EL1, BF16, IMP, CAP_HWCAP, KERNEL_HWCAP_BF16),

arch/arm64/kernel/cpuinfo.c

@@ -128,6 +128,7 @@ static const char *const hwcap_str[] = {
 	[KERNEL_HWCAP_MOPS]		= "mops",
 	[KERNEL_HWCAP_HBC]		= "hbc",
 	[KERNEL_HWCAP_SVE_B16B16]	= "sveb16b16",
+	[KERNEL_HWCAP_LRCPC3]		= "lrcpc3",
 };
 
 #ifdef CONFIG_COMPAT

arch/arm64/tools/sysreg

@@ -1309,6 +1309,7 @@ UnsignedEnum	23:20	LRCPC
 	0b0000	NI
 	0b0001	IMP
 	0b0010	LRCPC2
+	0b0011	LRCPC3
 EndEnum
 UnsignedEnum	19:16	FCMA
 	0b0000	NI

tools/testing/selftests/arm64/abi/hwcap.c

@@ -295,6 +295,19 @@ static void uscat_sigbus(void)
 	asm volatile(".inst 0xb820003f" : : : );
 }
 
+static void lrcpc3_sigill(void)
+{
+	int data[2] = { 1, 2 };
+
+	register int *src asm ("x0") = data;
+	register int data0 asm ("w2") = 0;
+	register int data1 asm ("w3") = 0;
+
+	/* LDIAPP w2, w3, [x0] */
+	asm volatile(".inst 0x99431802"
+	              : "=r" (data0), "=r" (data1) : "r" (src) :);
+}
+
 static const struct hwcap_data {
 	const char *name;
 	unsigned long at_hwcap;
@@ -354,6 +367,13 @@ static const struct hwcap_data {
 		.cpuinfo = "ilrcpc",
 		.sigill_fn = ilrcpc_sigill,
 	},
+	{
+		.name = "LRCPC3",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_LRCPC3,
+		.cpuinfo = "lrcpc3",
+		.sigill_fn = lrcpc3_sigill,
+	},
 	{
 		.name = "LSE",
 		.at_hwcap = AT_HWCAP,