diff options
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 57 |
1 files changed, 44 insertions, 13 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index cae3dcef0efa..b2903d5d3e29 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -510,7 +510,7 @@ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new) } extern const struct arm64_cpu_capabilities arm64_errata[]; -static void update_cpu_capabilities(u16 scope_mask); +static void __init setup_boot_cpu_capabilities(void); void __init init_cpu_features(struct cpuinfo_arm64 *info) { @@ -556,10 +556,10 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) } /* - * Run the errata work around and local feature checks on the - * boot CPU, once we have initialised the cpu feature infrastructure. + * Detect and enable early CPU capabilities based on the boot CPU, + * after we have initialised the CPU feature infrastructure. */ - update_cpu_capabilities(SCOPE_LOCAL_CPU); + setup_boot_cpu_capabilities(); } static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) @@ -1311,13 +1311,24 @@ __enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, if (caps->cpu_enable) { /* - * Use stop_machine() as it schedules the work allowing - * us to modify PSTATE, instead of on_each_cpu() which - * uses an IPI, giving us a PSTATE that disappears when - * we return. + * Capabilities with SCOPE_BOOT_CPU scope are finalised + * before any secondary CPU boots. Thus, each secondary + * will enable the capability as appropriate via + * check_local_cpu_capabilities(). The only exception is + * the boot CPU, for which the capability must be + * enabled here. This approach avoids costly + * stop_machine() calls for this case. + * + * Otherwise, use stop_machine() as it schedules the + * work allowing us to modify PSTATE, instead of + * on_each_cpu() which uses an IPI, giving us a PSTATE + * that disappears when we return. */ - stop_machine(__enable_cpu_capability, (void *)caps, - cpu_online_mask); + if (scope_mask & SCOPE_BOOT_CPU) + caps->cpu_enable(caps); + else + stop_machine(__enable_cpu_capability, + (void *)caps, cpu_online_mask); } } } @@ -1400,6 +1411,12 @@ static void check_early_cpu_features(void) { verify_cpu_run_el(); verify_cpu_asid_bits(); + /* + * Early features are used by the kernel already. If there + * is a conflict, we cannot proceed further. + */ + if (!verify_local_cpu_caps(SCOPE_BOOT_CPU)) + cpu_panic_kernel(); } static void @@ -1442,7 +1459,12 @@ static void verify_sve_features(void) */ static void verify_local_cpu_capabilities(void) { - if (!verify_local_cpu_caps(SCOPE_ALL)) + /* + * The capabilities with SCOPE_BOOT_CPU are checked from + * check_early_cpu_features(), as they need to be verified + * on all secondary CPUs. + */ + if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU)) cpu_die_early(); verify_local_elf_hwcaps(arm64_elf_hwcaps); @@ -1474,6 +1496,14 @@ void check_local_cpu_capabilities(void) verify_local_cpu_capabilities(); } +static void __init setup_boot_cpu_capabilities(void) +{ + /* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */ + update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU); + /* Enable the SCOPE_BOOT_CPU capabilities alone right away */ + enable_cpu_capabilities(SCOPE_BOOT_CPU); +} + DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready); EXPORT_SYMBOL(arm64_const_caps_ready); @@ -1495,10 +1525,11 @@ static void __init setup_system_capabilities(void) /* * We have finalised the system-wide safe feature * registers, finalise the capabilities that depend - * on it. Also enable all the available capabilities. + * on it. Also enable all the available capabilities, + * that are not enabled already. */ update_cpu_capabilities(SCOPE_SYSTEM); - enable_cpu_capabilities(SCOPE_ALL); + enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU); } void __init setup_cpu_features(void) |