[v4.4,17/45] arm64: cpufeature: Add scope for capability check

Message ID bb18f69cf06d3f04c1f323ccd338c83db6223db6.1560480942.git.viresh.kumar@linaro.org
State Superseded
Headers show
Series
  • V4.4 backport of arm64 Spectre patches
Related show

Commit Message

Viresh Kumar June 14, 2019, 3:08 a.m.
From: Suzuki K Poulose <suzuki.poulose@arm.com>


commit 92406f0cc9e3d5cc77bf3de6d68c9c2373dcd701 upstream.

Add scope parameter to the arm64_cpu_capabilities::matches(), so that
this can be reused for checking the capability on a given CPU vs the
system wide. The system uses the default scope associated with the
capability for initialising the CPU_HWCAPs and ELF_HWCAPs.

Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Signed-off-by: Will Deacon <will.deacon@arm.com>

[ v4.4: Changes made according to 4.4 codebase ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 arch/arm64/include/asm/cpufeature.h |   9 ++-
 arch/arm64/kernel/cpu_errata.c      |   5 +-
 arch/arm64/kernel/cpufeature.c      | 105 +++++++++++++++-------------
 3 files changed, 70 insertions(+), 49 deletions(-)

-- 
2.21.0.rc0.269.g1a574e7a288b

Patch

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index ad83c245781c..4c31e14c0f0e 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -74,10 +74,17 @@  struct arm64_ftr_reg {
 	struct arm64_ftr_bits	*ftr_bits;
 };
 
+/* scope of capability check */
+enum {
+	SCOPE_SYSTEM,
+	SCOPE_LOCAL_CPU,
+};
+
 struct arm64_cpu_capabilities {
 	const char *desc;
 	u16 capability;
-	bool (*matches)(const struct arm64_cpu_capabilities *);
+	int def_scope;			/* default scope */
+	bool (*matches)(const struct arm64_cpu_capabilities *caps, int scope);
 	int (*enable)(void *);		/* Called on all active CPUs */
 	union {
 		struct {	/* To be used for erratum handling only */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index a3e846a28b05..0971d80d3623 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -29,10 +29,12 @@ 
 			MIDR_ARCHITECTURE_MASK)
 
 static bool __maybe_unused
-is_affected_midr_range(const struct arm64_cpu_capabilities *entry)
+is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
 {
 	u32 midr = read_cpuid_id();
 
+	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+
 	if ((midr & CPU_MODEL_MASK) != entry->midr_model)
 		return false;
 
@@ -42,6 +44,7 @@  is_affected_midr_range(const struct arm64_cpu_capabilities *entry)
 }
 
 #define MIDR_RANGE(model, min, max) \
+	.def_scope = SCOPE_LOCAL_CPU, \
 	.matches = is_affected_midr_range, \
 	.midr_model = model, \
 	.midr_range_min = min, \
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c7a2827658fd..79c1cd9f15c2 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -589,6 +589,48 @@  u64 read_system_reg(u32 id)
 	return regp->sys_val;
 }
 
+/*
+ * __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
+ * Read the system register on the current CPU
+ */
+static u64 __raw_read_system_reg(u32 sys_id)
+{
+	switch (sys_id) {
+	case SYS_ID_PFR0_EL1:		return (u64)read_cpuid(ID_PFR0_EL1);
+	case SYS_ID_PFR1_EL1:		return (u64)read_cpuid(ID_PFR1_EL1);
+	case SYS_ID_DFR0_EL1:		return (u64)read_cpuid(ID_DFR0_EL1);
+	case SYS_ID_MMFR0_EL1:		return (u64)read_cpuid(ID_MMFR0_EL1);
+	case SYS_ID_MMFR1_EL1:		return (u64)read_cpuid(ID_MMFR1_EL1);
+	case SYS_ID_MMFR2_EL1:		return (u64)read_cpuid(ID_MMFR2_EL1);
+	case SYS_ID_MMFR3_EL1:		return (u64)read_cpuid(ID_MMFR3_EL1);
+	case SYS_ID_ISAR0_EL1:		return (u64)read_cpuid(ID_ISAR0_EL1);
+	case SYS_ID_ISAR1_EL1:		return (u64)read_cpuid(ID_ISAR1_EL1);
+	case SYS_ID_ISAR2_EL1:		return (u64)read_cpuid(ID_ISAR2_EL1);
+	case SYS_ID_ISAR3_EL1:		return (u64)read_cpuid(ID_ISAR3_EL1);
+	case SYS_ID_ISAR4_EL1:		return (u64)read_cpuid(ID_ISAR4_EL1);
+	case SYS_ID_ISAR5_EL1:		return (u64)read_cpuid(ID_ISAR4_EL1);
+	case SYS_MVFR0_EL1:		return (u64)read_cpuid(MVFR0_EL1);
+	case SYS_MVFR1_EL1:		return (u64)read_cpuid(MVFR1_EL1);
+	case SYS_MVFR2_EL1:		return (u64)read_cpuid(MVFR2_EL1);
+
+	case SYS_ID_AA64PFR0_EL1:	return (u64)read_cpuid(ID_AA64PFR0_EL1);
+	case SYS_ID_AA64PFR1_EL1:	return (u64)read_cpuid(ID_AA64PFR0_EL1);
+	case SYS_ID_AA64DFR0_EL1:	return (u64)read_cpuid(ID_AA64DFR0_EL1);
+	case SYS_ID_AA64DFR1_EL1:	return (u64)read_cpuid(ID_AA64DFR0_EL1);
+	case SYS_ID_AA64MMFR0_EL1:	return (u64)read_cpuid(ID_AA64MMFR0_EL1);
+	case SYS_ID_AA64MMFR1_EL1:	return (u64)read_cpuid(ID_AA64MMFR1_EL1);
+	case SYS_ID_AA64ISAR0_EL1:	return (u64)read_cpuid(ID_AA64ISAR0_EL1);
+	case SYS_ID_AA64ISAR1_EL1:	return (u64)read_cpuid(ID_AA64ISAR1_EL1);
+
+	case SYS_CNTFRQ_EL0:		return (u64)read_cpuid(CNTFRQ_EL0);
+	case SYS_CTR_EL0:		return (u64)read_cpuid(CTR_EL0);
+	case SYS_DCZID_EL0:		return (u64)read_cpuid(DCZID_EL0);
+	default:
+		BUG();
+		return 0;
+	}
+}
+
 #include <linux/irqchip/arm-gic-v3.h>
 
 static bool
@@ -600,19 +642,24 @@  feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
 }
 
 static bool
-has_cpuid_feature(const struct arm64_cpu_capabilities *entry)
+has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
 {
 	u64 val;
 
-	val = read_system_reg(entry->sys_reg);
+	WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
+	if (scope == SCOPE_SYSTEM)
+		val = read_system_reg(entry->sys_reg);
+	else
+		val = __raw_read_system_reg(entry->sys_reg);
+
 	return feature_matches(val, entry);
 }
 
-static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry)
+static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
 {
 	bool has_sre;
 
-	if (!has_cpuid_feature(entry))
+	if (!has_cpuid_feature(entry, scope))
 		return false;
 
 	has_sre = gic_enable_sre();
@@ -627,6 +674,7 @@  static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "GIC system register CPU interface",
 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
+		.def_scope = SCOPE_SYSTEM,
 		.matches = has_useable_gicv3_cpuif,
 		.sys_reg = SYS_ID_AA64PFR0_EL1,
 		.field_pos = ID_AA64PFR0_GIC_SHIFT,
@@ -636,6 +684,7 @@  static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "Privileged Access Never",
 		.capability = ARM64_HAS_PAN,
+		.def_scope = SCOPE_SYSTEM,
 		.matches = has_cpuid_feature,
 		.sys_reg = SYS_ID_AA64MMFR1_EL1,
 		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
@@ -647,6 +696,7 @@  static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "LSE atomic instructions",
 		.capability = ARM64_HAS_LSE_ATOMICS,
+		.def_scope = SCOPE_SYSTEM,
 		.matches = has_cpuid_feature,
 		.sys_reg = SYS_ID_AA64ISAR0_EL1,
 		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
@@ -656,6 +706,7 @@  static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "32-bit EL0 Support",
 		.capability = ARM64_HAS_32BIT_EL0,
+		.def_scope = SCOPE_SYSTEM,
 		.matches = has_cpuid_feature,
 		.sys_reg = SYS_ID_AA64PFR0_EL1,
 		.field_pos = ID_AA64PFR0_EL0_SHIFT,
@@ -667,6 +718,7 @@  static const struct arm64_cpu_capabilities arm64_features[] = {
 #define HWCAP_CAP(reg, field, min_value, type, cap)		\
 	{							\
 		.desc = #cap,					\
+		.def_scope = SCOPE_SYSTEM,			\
 		.matches = has_cpuid_feature,			\
 		.sys_reg = reg,					\
 		.field_pos = field,				\
@@ -745,7 +797,7 @@  static void setup_cpu_hwcaps(void)
 	const struct arm64_cpu_capabilities *hwcaps = arm64_hwcaps;
 
 	for (i = 0; hwcaps[i].desc; i++)
-		if (hwcaps[i].matches(&hwcaps[i]))
+		if (hwcaps[i].matches(&hwcaps[i], hwcaps[i].def_scope))
 			cap_set_hwcap(&hwcaps[i]);
 }
 
@@ -755,7 +807,7 @@  void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
 	int i;
 
 	for (i = 0; caps[i].desc; i++) {
-		if (!caps[i].matches(&caps[i]))
+		if (!caps[i].matches(&caps[i], caps[i].def_scope))
 			continue;
 
 		if (!cpus_have_cap(caps[i].capability))
@@ -800,47 +852,6 @@  static inline void set_sys_caps_initialised(void)
 	sys_caps_initialised = true;
 }
 
-/*
- * __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
- */
-static u64 __raw_read_system_reg(u32 sys_id)
-{
-	switch (sys_id) {
-	case SYS_ID_PFR0_EL1:		return (u64)read_cpuid(ID_PFR0_EL1);
-	case SYS_ID_PFR1_EL1:		return (u64)read_cpuid(ID_PFR1_EL1);
-	case SYS_ID_DFR0_EL1:		return (u64)read_cpuid(ID_DFR0_EL1);
-	case SYS_ID_MMFR0_EL1:		return (u64)read_cpuid(ID_MMFR0_EL1);
-	case SYS_ID_MMFR1_EL1:		return (u64)read_cpuid(ID_MMFR1_EL1);
-	case SYS_ID_MMFR2_EL1:		return (u64)read_cpuid(ID_MMFR2_EL1);
-	case SYS_ID_MMFR3_EL1:		return (u64)read_cpuid(ID_MMFR3_EL1);
-	case SYS_ID_ISAR0_EL1:		return (u64)read_cpuid(ID_ISAR0_EL1);
-	case SYS_ID_ISAR1_EL1:		return (u64)read_cpuid(ID_ISAR1_EL1);
-	case SYS_ID_ISAR2_EL1:		return (u64)read_cpuid(ID_ISAR2_EL1);
-	case SYS_ID_ISAR3_EL1:		return (u64)read_cpuid(ID_ISAR3_EL1);
-	case SYS_ID_ISAR4_EL1:		return (u64)read_cpuid(ID_ISAR4_EL1);
-	case SYS_ID_ISAR5_EL1:		return (u64)read_cpuid(ID_ISAR4_EL1);
-	case SYS_MVFR0_EL1:		return (u64)read_cpuid(MVFR0_EL1);
-	case SYS_MVFR1_EL1:		return (u64)read_cpuid(MVFR1_EL1);
-	case SYS_MVFR2_EL1:		return (u64)read_cpuid(MVFR2_EL1);
-
-	case SYS_ID_AA64PFR0_EL1:	return (u64)read_cpuid(ID_AA64PFR0_EL1);
-	case SYS_ID_AA64PFR1_EL1:	return (u64)read_cpuid(ID_AA64PFR0_EL1);
-	case SYS_ID_AA64DFR0_EL1:	return (u64)read_cpuid(ID_AA64DFR0_EL1);
-	case SYS_ID_AA64DFR1_EL1:	return (u64)read_cpuid(ID_AA64DFR0_EL1);
-	case SYS_ID_AA64MMFR0_EL1:	return (u64)read_cpuid(ID_AA64MMFR0_EL1);
-	case SYS_ID_AA64MMFR1_EL1:	return (u64)read_cpuid(ID_AA64MMFR1_EL1);
-	case SYS_ID_AA64ISAR0_EL1:	return (u64)read_cpuid(ID_AA64ISAR0_EL1);
-	case SYS_ID_AA64ISAR1_EL1:	return (u64)read_cpuid(ID_AA64ISAR1_EL1);
-
-	case SYS_CNTFRQ_EL0:		return (u64)read_cpuid(CNTFRQ_EL0);
-	case SYS_CTR_EL0:		return (u64)read_cpuid(CTR_EL0);
-	case SYS_DCZID_EL0:		return (u64)read_cpuid(DCZID_EL0);
-	default:
-		BUG();
-		return 0;
-	}
-}
-
 /*
  * Park the CPU which doesn't have the capability as advertised
  * by the system.