[PATCH] arm64: cpufeature: Make ID reg accessor naming less counterintuitive
Dave Martin
Dave.Martin at arm.com
Thu Mar 23 08:14:39 PDT 2017
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.
Signed-off-by: Dave Martin <Dave.Martin at arm.com>
---
This patch is implemented by a brainless global replace.
defconfig builds without warnings -- I haven't done any testing beyond
that.
arch/arm64/include/asm/cpufeature.h | 4 ++--
arch/arm64/include/asm/hw_breakpoint.h | 4 ++--
arch/arm64/include/asm/kvm_mmu.h | 2 +-
arch/arm64/kernel/cpufeature.c | 14 +++++++-------
arch/arm64/kernel/debug-monitors.c | 2 +-
arch/arm64/kvm/reset.c | 2 +-
arch/arm64/kvm/sys_regs.c | 4 ++--
7 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index f31c48d..e7f84a7 100644
--- 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 b6b167a..4177076 100644
--- 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 ed12460..7a5b12c 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -307,7 +307,7 @@ 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 abda8e8..6093b6a 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -585,7 +585,7 @@ 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,
@@ -636,7 +636,7 @@ 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);
@@ -649,10 +649,10 @@ 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);
@@ -709,9 +709,9 @@ 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);
}
@@ -761,7 +761,7 @@ 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 3291356..d618e25 100644
--- 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 d9e9697..561badf 100644
--- 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 0e26f8c..26b0e77 100644
--- 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) |
--
2.1.4
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