Merge tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...

[sfrench/cifs-2.6.git] / arch / arm64 / kernel / cpufeature.c

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 94b8f7fc33100f85db825a372bf36d6f597934ac..817ce3365e200dfb5f7ff205dadabe72c3490e43 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -985,8 +985,16 @@ void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
  */
 void __init enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
 {
-       for (; caps->matches; caps++)
-               if (caps->enable && cpus_have_cap(caps->capability))
+       for (; caps->matches; caps++) {
+               unsigned int num = caps->capability;
+
+               if (!cpus_have_cap(num))
+                       continue;
+
+               /* Ensure cpus_have_const_cap(num) works */
+               static_branch_enable(&cpu_hwcap_keys[num]);
+
+               if (caps->enable) {
                        /*
                         * Use stop_machine() as it schedules the work allowing
                         * us to modify PSTATE, instead of on_each_cpu() which
@@ -994,6 +1002,8 @@ void __init enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
                         * we return.
                         */
                        stop_machine(caps->enable, NULL, cpu_online_mask);
+               }
+       }
 }
 
 /*
@@ -1096,6 +1106,14 @@ static void __init setup_feature_capabilities(void)
        enable_cpu_capabilities(arm64_features);
 }
 
+DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
+EXPORT_SYMBOL(arm64_const_caps_ready);
+
+static void __init mark_const_caps_ready(void)
+{
+       static_branch_enable(&arm64_const_caps_ready);
+}
+
 /*
  * Check if the current CPU has a given feature capability.
  * Should be called from non-preemptible context.
@@ -1131,6 +1149,7 @@ void __init setup_cpu_features(void)
        /* Set the CPU feature capabilies */
        setup_feature_capabilities();
        enable_errata_workarounds();
+       mark_const_caps_ready();
        setup_elf_hwcaps(arm64_elf_hwcaps);
 
        if (system_supports_32bit_el0())