From: Suzuki K Poulose suzuki.poulose@arm.com
[ Upstream commit eaac4d83daa50fc1b9b7850346e9a62adfd4647e ]
Now that each capability describes how to treat the conflicts of CPU cap state vs System wide cap state, we can unify the verification logic to a single place.
Reviewed-by: Dave Martin dave.martin@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org --- arch/arm64/kernel/cpufeature.c | 91 +++++++++++++------- 1 file changed, 58 insertions(+), 33 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 70b504d84683..e73fae0c0ca7 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1228,6 +1228,58 @@ static inline void set_sys_caps_initialised(void) sys_caps_initialised = true; }
+/* + * Run through the list of capabilities to check for conflicts. + * If the system has already detected a capability, take necessary + * action on this CPU. + * + * Returns "false" on conflicts. + */ +static bool +__verify_local_cpu_caps(const struct arm64_cpu_capabilities *caps_list) +{ + bool cpu_has_cap, system_has_cap; + const struct arm64_cpu_capabilities *caps; + + for (caps = caps_list; caps->matches; caps++) { + cpu_has_cap = __this_cpu_has_cap(caps_list, caps->capability); + system_has_cap = cpus_have_cap(caps->capability); + + if (system_has_cap) { + /* + * Check if the new CPU misses an advertised feature, + * which is not safe to miss. + */ + if (!cpu_has_cap && !cpucap_late_cpu_optional(caps)) + break; + /* + * We have to issue cpu_enable() irrespective of + * whether the CPU has it or not, as it is enabeld + * system wide. It is upto the call back to take + * appropriate action on this CPU. + */ + if (caps->cpu_enable) + caps->cpu_enable(caps); + } else { + /* + * Check if the CPU has this capability if it isn't + * safe to have when the system doesn't. + */ + if (cpu_has_cap && !cpucap_late_cpu_permitted(caps)) + break; + } + } + + if (caps->matches) { + pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n", + smp_processor_id(), caps->capability, + caps->desc, system_has_cap, cpu_has_cap); + return false; + } + + return true; +} + /* * Check for CPU features that are used in early boot * based on the Boot CPU value. @@ -1250,25 +1302,10 @@ verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps) } }
-static void -verify_local_cpu_features(const struct arm64_cpu_capabilities *caps_list) +static void verify_local_cpu_features(void) { - const struct arm64_cpu_capabilities *caps = caps_list; - for (; caps->matches; caps++) { - if (!cpus_have_cap(caps->capability)) - continue; - /* - * If the new CPU misses an advertised feature, we cannot proceed - * further, park the cpu. - */ - if (!__this_cpu_has_cap(caps_list, caps->capability)) { - pr_crit("CPU%d: missing feature: %s\n", - smp_processor_id(), caps->desc); - cpu_die_early(); - } - if (caps->cpu_enable) - caps->cpu_enable(caps); - } + if (!__verify_local_cpu_caps(arm64_features)) + cpu_die_early(); }
/* @@ -1278,20 +1315,8 @@ verify_local_cpu_features(const struct arm64_cpu_capabilities *caps_list) */ static void verify_local_cpu_errata_workarounds(void) { - const struct arm64_cpu_capabilities *caps = arm64_errata; - - for (; caps->matches; caps++) { - if (cpus_have_cap(caps->capability)) { - if (caps->cpu_enable) - caps->cpu_enable(caps); - } else if (caps->matches(caps, SCOPE_LOCAL_CPU)) { - pr_crit("CPU%d: Requires work around for %s, not detected" - " at boot time\n", - smp_processor_id(), - caps->desc ? : "an erratum"); - cpu_die_early(); - } - } + if (!__verify_local_cpu_caps(arm64_errata)) + cpu_die_early(); }
static void update_cpu_errata_workarounds(void) @@ -1315,7 +1340,7 @@ static void __init enable_errata_workarounds(void) static void verify_local_cpu_capabilities(void) { verify_local_cpu_errata_workarounds(); - verify_local_cpu_features(arm64_features); + verify_local_cpu_features(); verify_local_elf_hwcaps(arm64_elf_hwcaps); if (system_supports_32bit_el0()) verify_local_elf_hwcaps(compat_elf_hwcaps);