1 files changed, 32 insertions, 81 deletions

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6b3ac96ef717..1767927adfe8 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -613,18 +613,6 @@ static const struct arm64_ftr_bits ftr_id_dfr1[] = {
 	ARM64_FTR_END,
 };
 
-static const struct arm64_ftr_bits ftr_zcr[] = {
-	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
-		ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_WIDTH, 0),	/* LEN */
-	ARM64_FTR_END,
-};
-
-static const struct arm64_ftr_bits ftr_smcr[] = {
-	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
-		SMCR_ELx_LEN_SHIFT, SMCR_ELx_LEN_WIDTH, 0),	/* LEN */
-	ARM64_FTR_END,
-};
-
 /*
  * Common ftr bits for a 32bit register with all hidden, strict
  * attributes, with 4bit feature fields and a default safe value of
@@ -737,10 +725,6 @@ static const struct __ftr_reg_entry {
 	ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
 	ARM64_FTR_REG(SYS_ID_AA64MMFR3_EL1, ftr_id_aa64mmfr3),
 
-	/* Op1 = 0, CRn = 1, CRm = 2 */
-	ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
-	ARM64_FTR_REG(SYS_SMCR_EL1, ftr_smcr),
-
 	/* Op1 = 1, CRn = 0, CRm = 0 */
 	ARM64_FTR_REG(SYS_GMID_EL1, ftr_gmid),
 
@@ -1042,21 +1026,20 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
 
 	if (IS_ENABLED(CONFIG_ARM64_SVE) &&
 	    id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
-		info->reg_zcr = read_zcr_features();
-		init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
+		sve_kernel_enable(NULL);
 		vec_init_vq_map(ARM64_VEC_SVE);
 	}
 
 	if (IS_ENABLED(CONFIG_ARM64_SME) &&
 	    id_aa64pfr1_sme(read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1))) {
-		info->reg_smcr = read_smcr_features();
+		sme_kernel_enable(NULL);
+
 		/*
 		 * We mask out SMPS since even if the hardware
 		 * supports priorities the kernel does not at present
 		 * and we block access to them.
 		 */
 		info->reg_smidr = read_cpuid(SMIDR_EL1) & ~SMIDR_EL1_SMPS;
-		init_cpu_ftr_reg(SYS_SMCR_EL1, info->reg_smcr);
 		vec_init_vq_map(ARM64_VEC_SME);
 	}
 
@@ -1291,28 +1274,25 @@ void update_cpu_features(int cpu,
 	taint |= check_update_ftr_reg(SYS_ID_AA64SMFR0_EL1, cpu,
 				      info->reg_id_aa64smfr0, boot->reg_id_aa64smfr0);
 
+	/* Probe vector lengths */
 	if (IS_ENABLED(CONFIG_ARM64_SVE) &&
 	    id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
-		info->reg_zcr = read_zcr_features();
-		taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
-					info->reg_zcr, boot->reg_zcr);
-
-		/* Probe vector lengths */
-		if (!system_capabilities_finalized())
+		if (!system_capabilities_finalized()) {
+			sve_kernel_enable(NULL);
 			vec_update_vq_map(ARM64_VEC_SVE);
+		}
 	}
 
 	if (IS_ENABLED(CONFIG_ARM64_SME) &&
 	    id_aa64pfr1_sme(read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1))) {
-		info->reg_smcr = read_smcr_features();
+		sme_kernel_enable(NULL);
+
 		/*
 		 * We mask out SMPS since even if the hardware
 		 * supports priorities the kernel does not at present
 		 * and we block access to them.
 		 */
 		info->reg_smidr = read_cpuid(SMIDR_EL1) & ~SMIDR_EL1_SMPS;
-		taint |= check_update_ftr_reg(SYS_SMCR_EL1, cpu,
-					info->reg_smcr, boot->reg_smcr);
 
 		/* Probe vector lengths */
 		if (!system_capabilities_finalized())
@@ -1850,6 +1830,8 @@ static int __init parse_kpti(char *str)
 early_param("kpti", parse_kpti);
 
 #ifdef CONFIG_ARM64_HW_AFDBM
+static struct cpumask dbm_cpus __read_mostly;
+
 static inline void __cpu_enable_hw_dbm(void)
 {
 	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
@@ -1885,35 +1867,22 @@ static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
 
 static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
 {
-	if (cpu_can_use_dbm(cap))
+	if (cpu_can_use_dbm(cap)) {
 		__cpu_enable_hw_dbm();
+		cpumask_set_cpu(smp_processor_id(), &dbm_cpus);
+	}
 }
 
 static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
 		       int __unused)
 {
-	static bool detected = false;
 	/*
 	 * DBM is a non-conflicting feature. i.e, the kernel can safely
 	 * run a mix of CPUs with and without the feature. So, we
 	 * unconditionally enable the capability to allow any late CPU
 	 * to use the feature. We only enable the control bits on the
-	 * CPU, if it actually supports.
-	 *
-	 * We have to make sure we print the "feature" detection only
-	 * when at least one CPU actually uses it. So check if this CPU
-	 * can actually use it and print the message exactly once.
-	 *
-	 * This is safe as all CPUs (including secondary CPUs - due to the
-	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
-	 * goes through the "matches" check exactly once. Also if a CPU
-	 * matches the criteria, it is guaranteed that the CPU will turn
-	 * the DBM on, as the capability is unconditionally enabled.
+	 * CPU, if it is supported.
 	 */
-	if (!detected && cpu_can_use_dbm(cap)) {
-		detected = true;
-		pr_info("detected: Hardware dirty bit management\n");
-	}
 
 	return true;
 }
@@ -1946,8 +1915,6 @@ int get_cpu_with_amu_feat(void)
 static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
 {
 	if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
-		pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
-			smp_processor_id());
 		cpumask_set_cpu(smp_processor_id(), &amu_cpus);
 
 		/* 0 reference values signal broken/disabled counters */
@@ -2407,16 +2374,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 #endif /* CONFIG_ARM64_RAS_EXTN */
 #ifdef CONFIG_ARM64_AMU_EXTN
 	{
-		/*
-		 * The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
-		 * Therefore, don't provide .desc as we don't want the detection
-		 * message to be shown until at least one CPU is detected to
-		 * support the feature.
-		 */
+		.desc = "Activity Monitors Unit (AMU)",
 		.capability = ARM64_HAS_AMU_EXTN,
 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
 		.matches = has_amu,
 		.cpu_enable = cpu_amu_enable,
+		.cpus = &amu_cpus,
 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, AMU, IMP)
 	},
 #endif /* CONFIG_ARM64_AMU_EXTN */
@@ -2456,18 +2419,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 	},
 #ifdef CONFIG_ARM64_HW_AFDBM
 	{
-		/*
-		 * Since we turn this on always, we don't want the user to
-		 * think that the feature is available when it may not be.
-		 * So hide the description.
-		 *
-		 * .desc = "Hardware pagetable Dirty Bit Management",
-		 *
-		 */
+		.desc = "Hardware dirty bit management",
 		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
 		.capability = ARM64_HW_DBM,
 		.matches = has_hw_dbm,
 		.cpu_enable = cpu_enable_hw_dbm,
+		.cpus = &dbm_cpus,
 		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, HAFDBS, DBM)
 	},
 #endif
@@ -2986,7 +2943,7 @@ static void update_cpu_capabilities(u16 scope_mask)
 		    !caps->matches(caps, cpucap_default_scope(caps)))
 			continue;
 
-		if (caps->desc)
+		if (caps->desc && !caps->cpus)
 			pr_info("detected: %s\n", caps->desc);
 
 		__set_bit(caps->capability, system_cpucaps);
@@ -3158,36 +3115,20 @@ static void verify_local_elf_hwcaps(void)
 
 static void verify_sve_features(void)
 {
-	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
-	u64 zcr = read_zcr_features();
-
-	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
-	unsigned int len = zcr & ZCR_ELx_LEN_MASK;
-
-	if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SVE)) {
+	if (vec_verify_vq_map(ARM64_VEC_SVE)) {
 		pr_crit("CPU%d: SVE: vector length support mismatch\n",
 			smp_processor_id());
 		cpu_die_early();
 	}
-
-	/* Add checks on other ZCR bits here if necessary */
 }
 
 static void verify_sme_features(void)
 {
-	u64 safe_smcr = read_sanitised_ftr_reg(SYS_SMCR_EL1);
-	u64 smcr = read_smcr_features();
-
-	unsigned int safe_len = safe_smcr & SMCR_ELx_LEN_MASK;
-	unsigned int len = smcr & SMCR_ELx_LEN_MASK;
-
-	if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SME)) {
+	if (vec_verify_vq_map(ARM64_VEC_SME)) {
 		pr_crit("CPU%d: SME: vector length support mismatch\n",
 			smp_processor_id());
 		cpu_die_early();
 	}
-
-	/* Add checks on other SMCR bits here if necessary */
 }
 
 static void verify_hyp_capabilities(void)
@@ -3335,6 +3276,7 @@ unsigned long cpu_get_elf_hwcap2(void)
 
 static void __init setup_system_capabilities(void)
 {
+	int i;
 	/*
 	 * We have finalised the system-wide safe feature
 	 * registers, finalise the capabilities that depend
@@ -3343,6 +3285,15 @@ static void __init setup_system_capabilities(void)
 	 */
 	update_cpu_capabilities(SCOPE_SYSTEM);
 	enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
+
+	for (i = 0; i < ARM64_NCAPS; i++) {
+		const struct arm64_cpu_capabilities *caps = cpucap_ptrs[i];
+
+		if (caps && caps->cpus && caps->desc &&
+			cpumask_any(caps->cpus) < nr_cpu_ids)
+			pr_info("detected: %s on CPU%*pbl\n",
+				caps->desc, cpumask_pr_args(caps->cpus));
+	}
 }
 
 void __init setup_cpu_features(void)