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

* for-next/cpufeature:
  kselftest/arm64: Add SVE 2.1 to hwcap test
  arm64/hwcap: Add support for SVE 2.1
  kselftest/arm64: Add FEAT_RPRFM to the hwcap test
  arm64/hwcap: Add support for FEAT_RPRFM
  kselftest/arm64: Add FEAT_CSSC to the hwcap selftest
  arm64/hwcap: Add support for FEAT_CSSC
  arm64: Enable data independent timing (DIT) in the kernel

Documentation/arm64/elf_hwcaps.rst

@@ -275,6 +275,15 @@ HWCAP2_EBF16
 HWCAP2_SVE_EBF16
     Functionality implied by ID_AA64ZFR0_EL1.BF16 == 0b0010.
 
+HWCAP2_CSSC
+    Functionality implied by ID_AA64ISAR2_EL1.CSSC == 0b0001.
+
+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

@@ -120,6 +120,9 @@
 #define KERNEL_HWCAP_WFXT		__khwcap2_feature(WFXT)
 #define KERNEL_HWCAP_EBF16		__khwcap2_feature(EBF16)
 #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/asm/sysreg.h

@@ -90,20 +90,24 @@
  */
 #define pstate_field(op1, op2)		((op1) << Op1_shift | (op2) << Op2_shift)
 #define PSTATE_Imm_shift		CRm_shift
+#define SET_PSTATE(x, r)		__emit_inst(0xd500401f | PSTATE_ ## r | ((!!x) << PSTATE_Imm_shift))
 
 #define PSTATE_PAN			pstate_field(0, 4)
 #define PSTATE_UAO			pstate_field(0, 3)
 #define PSTATE_SSBS			pstate_field(3, 1)
+#define PSTATE_DIT			pstate_field(3, 2)
 #define PSTATE_TCO			pstate_field(3, 4)
 
-#define SET_PSTATE_PAN(x)		__emit_inst(0xd500401f | PSTATE_PAN | ((!!x) << PSTATE_Imm_shift))
-#define SET_PSTATE_UAO(x)		__emit_inst(0xd500401f | PSTATE_UAO | ((!!x) << PSTATE_Imm_shift))
-#define SET_PSTATE_SSBS(x)		__emit_inst(0xd500401f | PSTATE_SSBS | ((!!x) << PSTATE_Imm_shift))
-#define SET_PSTATE_TCO(x)		__emit_inst(0xd500401f | PSTATE_TCO | ((!!x) << PSTATE_Imm_shift))
+#define SET_PSTATE_PAN(x)		SET_PSTATE((x), PAN)
+#define SET_PSTATE_UAO(x)		SET_PSTATE((x), UAO)
+#define SET_PSTATE_SSBS(x)		SET_PSTATE((x), SSBS)
+#define SET_PSTATE_DIT(x)		SET_PSTATE((x), DIT)
+#define SET_PSTATE_TCO(x)		SET_PSTATE((x), TCO)
 
 #define set_pstate_pan(x)		asm volatile(SET_PSTATE_PAN(x))
 #define set_pstate_uao(x)		asm volatile(SET_PSTATE_UAO(x))
 #define set_pstate_ssbs(x)		asm volatile(SET_PSTATE_SSBS(x))
+#define set_pstate_dit(x)		asm volatile(SET_PSTATE_DIT(x))
 
 #define __SYS_BARRIER_INSN(CRm, op2, Rt) \
 	__emit_inst(0xd5000000 | sys_insn(0, 3, 3, (CRm), (op2)) | ((Rt) & 0x1f))

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

@@ -93,5 +93,8 @@
 #define HWCAP2_WFXT		(1UL << 31)
 #define HWCAP2_EBF16		(1UL << 32)
 #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

@@ -212,6 +212,8 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
 };
 
 static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
+	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
 		       FTR_STRICT, FTR_EXACT, ID_AA64ISAR2_EL1_APA3_SHIFT, 4, 0),
@@ -2101,6 +2103,11 @@ static void cpu_trap_el0_impdef(const struct arm64_cpu_capabilities *__unused)
 	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_TIDCP);
 }
 
+static void cpu_enable_dit(const struct arm64_cpu_capabilities *__unused)
+{
+	set_pstate_dit(1);
+}
+
 /* Internal helper functions to match cpu capability type */
 static bool
 cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
@@ -2664,6 +2671,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.matches = has_cpuid_feature,
 		.cpu_enable = cpu_trap_el0_impdef,
 	},
+	{
+		.desc = "Data independent timing control (DIT)",
+		.capability = ARM64_HAS_DIT,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.sys_reg = SYS_ID_AA64PFR0_EL1,
+		.sign = FTR_UNSIGNED,
+		.field_pos = ID_AA64PFR0_EL1_DIT_SHIFT,
+		.field_width = 4,
+		.min_field_value = ID_AA64PFR0_EL1_DIT_IMP,
+		.matches = has_cpuid_feature,
+		.cpu_enable = cpu_enable_dit,
+	},
 	{},
 };
 
@@ -2772,6 +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),
@@ -2798,6 +2818,8 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 #endif /* CONFIG_ARM64_MTE */
 	HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_EL1_ECV_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV),
 	HWCAP_CAP(SYS_ID_AA64MMFR1_EL1, ID_AA64MMFR1_EL1_AFP_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AFP),
+	HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_EL1_CSSC_IMP, CAP_HWCAP, KERNEL_HWCAP_CSSC),
+	HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_EL1_RPRFM_IMP, CAP_HWCAP, KERNEL_HWCAP_RPRFM),
 	HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_RPRES_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RPRES),
 	HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_EL1_WFxT_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_EL1_WFxT_IMP, CAP_HWCAP, KERNEL_HWCAP_WFXT),
 #ifdef CONFIG_ARM64_SME

arch/arm64/kernel/cpuinfo.c

@@ -116,6 +116,9 @@ static const char *const hwcap_str[] = {
 	[KERNEL_HWCAP_WFXT]		= "wfxt",
 	[KERNEL_HWCAP_EBF16]		= "ebf16",
 	[KERNEL_HWCAP_SVE_EBF16]	= "sveebf16",
+	[KERNEL_HWCAP_CSSC]		= "cssc",
+	[KERNEL_HWCAP_RPRFM]		= "rprfm",
+	[KERNEL_HWCAP_SVE2P1]		= "sve2p1",
 };
 
 #ifdef CONFIG_COMPAT

arch/arm64/kernel/entry.S

@@ -197,6 +197,9 @@ alternative_cb_end
 	.endm
 
 	.macro	kernel_entry, el, regsize = 64
+	.if	\el == 0
+	alternative_insn nop, SET_PSTATE_DIT(1), ARM64_HAS_DIT
+	.endif
 	.if	\regsize == 32
 	mov	w0, w0				// zero upper 32 bits of x0
 	.endif

arch/arm64/kernel/suspend.c

@@ -60,6 +60,8 @@ void notrace __cpu_suspend_exit(void)
 	 * PSTATE was not saved over suspend/resume, re-enable any detected
 	 * features that might not have been set correctly.
 	 */
+	if (cpus_have_const_cap(ARM64_HAS_DIT))
+		set_pstate_dit(1);
 	__uaccess_enable_hw_pan();
 
 	/*

arch/arm64/tools/cpucaps

@@ -20,6 +20,7 @@ HAS_CNP
 HAS_CRC32
 HAS_DCPODP
 HAS_DCPOP
+HAS_DIT
 HAS_E0PD
 HAS_ECV
 HAS_EPAN

arch/arm64/tools/sysreg

@@ -210,6 +210,7 @@ EndEnum
 Enum	3:0	SVEver
 	0b0000	IMP
 	0b0001	SVE2
+	0b0010	SVE2p1
 EndEnum
 EndSysreg
 
@@ -484,7 +485,16 @@ EndEnum
 EndSysreg
 
 Sysreg	ID_AA64ISAR2_EL1	3	0	0	6	2
-Res0	63:28
+Res0	63:56
+Enum	55:52	CSSC
+	0b0000	NI
+	0b0001	IMP
+EndEnum
+Enum	51:48	RPRFM
+	0b0000	NI
+	0b0001	IMP
+EndEnum
+Res0	47:28
 Enum	27:24	PAC_frac
 	0b0000	NI
 	0b0001	IMP

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

@@ -33,6 +33,12 @@
  */
 typedef void (*sigill_fn)(void);
 
+static void cssc_sigill(void)
+{
+	/* CNT x0, x0 */
+	asm volatile(".inst 0xdac01c00" : : : "x0");
+}
+
 static void rng_sigill(void)
 {
 	asm volatile("mrs x0, S3_3_C2_C4_0" : : : "x0");
@@ -56,6 +62,12 @@ static void sve2_sigill(void)
 	asm volatile(".inst 0x4408A000" : : : "z0");
 }
 
+static void sve2p1_sigill(void)
+{
+	/* BFADD Z0.H, Z0.H, Z0.H */
+	asm volatile(".inst 0x65000000" : : : "z0");
+}
+
 static void sveaes_sigill(void)
 {
 	/* AESD z0.b, z0.b, z0.b */
@@ -118,6 +130,13 @@ static const struct hwcap_data {
 	sigill_fn sigill_fn;
 	bool sigill_reliable;
 } hwcaps[] = {
+	{
+		.name = "CSSC",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_CSSC,
+		.cpuinfo = "cssc",
+		.sigill_fn = cssc_sigill,
+	},
 	{
 		.name = "RNG",
 		.at_hwcap = AT_HWCAP2,
@@ -125,6 +144,12 @@ static const struct hwcap_data {
 		.cpuinfo = "rng",
 		.sigill_fn = rng_sigill,
 	},
+	{
+		.name = "RPRFM",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_RPRFM,
+		.cpuinfo = "rprfm",
+	},
 	{
 		.name = "SME",
 		.at_hwcap = AT_HWCAP2,
@@ -148,6 +173,13 @@ static const struct hwcap_data {
 		.cpuinfo = "sve2",
 		.sigill_fn = sve2_sigill,
 	},
+	{
+		.name = "SVE 2.1",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_SVE2P1,
+		.cpuinfo = "sve2p1",
+		.sigill_fn = sve2p1_sigill,
+	},
 	{
 		.name = "SVE AES",
 		.at_hwcap = AT_HWCAP2,