Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 46823dd1 authored by Dave Martin's avatar Dave Martin Committed by Catalin Marinas
Browse files

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: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 29d98121

arch/arm64/include/asm/cpufeature.h

+2 −2
Original line number Diff line number Diff line
@@ -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)

arch/arm64/include/asm/hw_breakpoint.h

+2 −2
Original line number Diff line number Diff line
@@ -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);

arch/arm64/include/asm/kvm_mmu.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

}

arch/arm64/kernel/cpufeature.c

+7 −7
Original line number Diff line number Diff line
@@ -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;

arch/arm64/kernel/debug-monitors.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

}