arm64/capabilities: Make use of system wide safe value

Now that we can reliably read the system wide safe value for a
feature register, use that to compute the system capability.
This patch also replaces the 'feature-register-specific'
methods with a generic routine to check the capability.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 1603ae84ea45c5bbbf6729f07b373417bcc61705..eec584e7c701ec0f0e6d878ee735c5e08e910d8d 100644 (file)
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -78,6 +78,7 @@ struct arm64_cpu_capabilities {
                };
 
                struct {        /* Feature register checking */
+                       u32 sys_reg;
                        int field_pos;
                        int min_field_value;
                };

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index e002cadf84bf148cc3d1bea82d15ee268f7b7656..8aff8fcbeb96f9f2692403000c65919c6c5d11e8 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -586,34 +586,31 @@ feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
        return val >= entry->min_field_value;
 }
 
-#define __ID_FEAT_CHK(reg)                                             \
-static bool __maybe_unused                                             \
-has_##reg##_feature(const struct arm64_cpu_capabilities *entry)                \
-{                                                                      \
-       u64 val;                                                        \
-                                                                       \
-       val = read_cpuid(reg##_el1);                                    \
-       return feature_matches(val, entry);                             \
-}
+static bool
+has_cpuid_feature(const struct arm64_cpu_capabilities *entry)
+{
+       u64 val;
 
-__ID_FEAT_CHK(id_aa64pfr0);
-__ID_FEAT_CHK(id_aa64mmfr1);
-__ID_FEAT_CHK(id_aa64isar0);
+       val = read_system_reg(entry->sys_reg);
+       return feature_matches(val, entry);
+}
 
 static const struct arm64_cpu_capabilities arm64_features[] = {
        {
                .desc = "GIC system register CPU interface",
                .capability = ARM64_HAS_SYSREG_GIC_CPUIF,
-               .matches = has_id_aa64pfr0_feature,
-               .field_pos = 24,
+               .matches = has_cpuid_feature,
+               .sys_reg = SYS_ID_AA64PFR0_EL1,
+               .field_pos = ID_AA64PFR0_GIC_SHIFT,
                .min_field_value = 1,
        },
 #ifdef CONFIG_ARM64_PAN
        {
                .desc = "Privileged Access Never",
                .capability = ARM64_HAS_PAN,
-               .matches = has_id_aa64mmfr1_feature,
-               .field_pos = 20,
+               .matches = has_cpuid_feature,
+               .sys_reg = SYS_ID_AA64MMFR1_EL1,
+               .field_pos = ID_AA64MMFR1_PAN_SHIFT,
                .min_field_value = 1,
                .enable = cpu_enable_pan,
        },
@@ -622,8 +619,9 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
        {
                .desc = "LSE atomic instructions",
                .capability = ARM64_HAS_LSE_ATOMICS,
-               .matches = has_id_aa64isar0_feature,
-               .field_pos = 20,
+               .matches = has_cpuid_feature,
+               .sys_reg = SYS_ID_AA64ISAR0_EL1,
+               .field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
                .min_field_value = 2,
        },
 #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
@@ -675,6 +673,47 @@ 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.
@@ -719,13 +758,13 @@ void verify_local_cpu_capabilities(void)
 
        caps = arm64_features;
        for (i = 0; caps[i].desc; i++) {
-               if (!cpus_have_cap(caps[i].capability))
+               if (!cpus_have_cap(caps[i].capability) || !caps[i].sys_reg)
                        continue;
                /*
                 * If the new CPU misses an advertised feature, we cannot proceed
                 * further, park the cpu.
                 */
-               if (!caps[i].matches(&caps[i]))
+               if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
                        fail_incapable_cpu("arm64_features", &caps[i]);
                if (caps[i].enable)
                        caps[i].enable(NULL);