arm64: cpufeature: Make ID reg accessor naming less counterintuitive

read_system_reg() can readily be confused with read_sysreg(),
whereas these are really quite different in their meaning.

This patches attempts to reduce the ambiguity be reserving "sysreg"
for the actual system register accessors.

read_system_reg() is instead renamed to read_sanitised_ftr_reg(),
to make it more obvious that the Linux-defined sanitised feature
register cache is being accessed here, not the underlying
architectural system registers.

cpufeature.c's internal __raw_read_system_reg() function is renamed
in line with its actual purpose: a form of read_sysreg() that
indexes on (non-compiletime-constant) encoding rather than symbolic
register name.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-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 f31c48d0cd6873f399a6d8f5f861e98fa3f66e10..e7f84a7b44658d2f93d642e06e013300693d6a82 100644 (file)
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -226,7 +226,7 @@ void update_cpu_errata_workarounds(void);
 void __init enable_errata_workarounds(void);
 void verify_local_cpu_errata_workarounds(void);
 
-u64 read_system_reg(u32 id);
+u64 read_sanitised_ftr_reg(u32 id);
 
 static inline bool cpu_supports_mixed_endian_el0(void)
 {
@@ -240,7 +240,7 @@ static inline bool system_supports_32bit_el0(void)
 
 static inline bool system_supports_mixed_endian_el0(void)
 {
-       return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
+       return id_aa64mmfr0_mixed_endian_el0(read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1));
 }
 
 static inline bool system_supports_fpsimd(void)

diff --git a/arch/arm64/include/asm/hw_breakpoint.h b/arch/arm64/include/asm/hw_breakpoint.h
index b6b167ac082b69f04416a788efae6fba13c7343d..41770766d9648f1dd03568f5d2adc86f95f77e3a 100644 (file)
--- a/arch/arm64/include/asm/hw_breakpoint.h
+++ b/arch/arm64/include/asm/hw_breakpoint.h
@@ -149,7 +149,7 @@ static inline void ptrace_hw_copy_thread(struct task_struct *task)
 /* Determine number of BRP registers available. */
 static inline int get_num_brps(void)
 {
-       u64 dfr0 = read_system_reg(SYS_ID_AA64DFR0_EL1);
+       u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
        return 1 +
                cpuid_feature_extract_unsigned_field(dfr0,
                                                ID_AA64DFR0_BRPS_SHIFT);
@@ -158,7 +158,7 @@ static inline int get_num_brps(void)
 /* Determine number of WRP registers available. */
 static inline int get_num_wrps(void)
 {
-       u64 dfr0 = read_system_reg(SYS_ID_AA64DFR0_EL1);
+       u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
        return 1 +
                cpuid_feature_extract_unsigned_field(dfr0,
                                                ID_AA64DFR0_WRPS_SHIFT);

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index d2293d49f55547543efec750d6cbaf606cbcfc05..2bc6ffa7b89b39eb7ee3f9fdebac084bdf52bf97 100644 (file)
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -308,7 +308,7 @@ static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd,
 
 static inline unsigned int kvm_get_vmid_bits(void)
 {
-       int reg = read_system_reg(SYS_ID_AA64MMFR1_EL1);
+       int reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
 
        return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8;
 }

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 81a78d9331ea4e352b7d43d1dfebac58a2667454..3e0d4f1ab5da5aed0230a1cd77784ea72a3cf1e7 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -592,7 +592,7 @@ void update_cpu_features(int cpu,
         * If we have AArch32, we care about 32-bit features for compat.
         * If the system doesn't support AArch32, don't update them.
         */
-       if (id_aa64pfr0_32bit_el0(read_system_reg(SYS_ID_AA64PFR0_EL1)) &&
+       if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
                id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
 
                taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
@@ -643,7 +643,7 @@ void update_cpu_features(int cpu,
                        "Unsupported CPU feature variation.\n");
 }
 
-u64 read_system_reg(u32 id)
+u64 read_sanitised_ftr_reg(u32 id)
 {
        struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
 
@@ -656,10 +656,10 @@ u64 read_system_reg(u32 id)
        case r:         return read_sysreg_s(r)
 
 /*
- * __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
+ * __read_sysreg_by_encoding() - 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)
+static u64 __read_sysreg_by_encoding(u32 sys_id)
 {
        switch (sys_id) {
        read_sysreg_case(SYS_ID_PFR0_EL1);
@@ -716,9 +716,9 @@ has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
 
        WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
        if (scope == SCOPE_SYSTEM)
-               val = read_system_reg(entry->sys_reg);
+               val = read_sanitised_ftr_reg(entry->sys_reg);
        else
-               val = __raw_read_system_reg(entry->sys_reg);
+               val = __read_sysreg_by_encoding(entry->sys_reg);
 
        return feature_matches(val, entry);
 }
@@ -768,7 +768,7 @@ static bool hyp_offset_low(const struct arm64_cpu_capabilities *entry,
 
 static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
 {
-       u64 pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1);
+       u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
 
        return cpuid_feature_extract_signed_field(pfr0,
                                        ID_AA64PFR0_FP_SHIFT) < 0;

diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 32913567da087d9bf993b21c112c5a4124ef6e41..d618e25c3de11c1ef379797edd0ae296beb0422f 100644 (file)
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -36,7 +36,7 @@
 /* Determine debug architecture. */
 u8 debug_monitors_arch(void)
 {
-       return cpuid_feature_extract_unsigned_field(read_system_reg(SYS_ID_AA64DFR0_EL1),
+       return cpuid_feature_extract_unsigned_field(read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1),
                                                ID_AA64DFR0_DEBUGVER_SHIFT);
 }
 

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index d9e9697de1b2bad70fe034e9f2114a80ccaf25db..561badf93de8602ca17bd79e1eab7440c12b4b7e 100644 (file)
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -60,7 +60,7 @@ static bool cpu_has_32bit_el1(void)
 {
        u64 pfr0;
 
-       pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1);
+       pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
        return !!(pfr0 & 0x20);
 }
 

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0e26f8c2b56f8270a6ff4bc5d3a3a1ba2e1c3210..26b0e77878b5e9cf545fb6047a154ace24655863 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1183,8 +1183,8 @@ static bool trap_dbgidr(struct kvm_vcpu *vcpu,
        if (p->is_write) {
                return ignore_write(vcpu, p);
        } else {
-               u64 dfr = read_system_reg(SYS_ID_AA64DFR0_EL1);
-               u64 pfr = read_system_reg(SYS_ID_AA64PFR0_EL1);
+               u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
+               u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
                u32 el3 = !!cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR0_EL3_SHIFT);
 
                p->regval = ((((dfr >> ID_AA64DFR0_WRPS_SHIFT) & 0xf) << 28) |