Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block

[karo-tx-linux.git] / arch / x86 / kernel / smpboot.c

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 0e4329ed91ef61da5a86e5d604d1ad96109efbfb..d0a51939c15040e859d88752aae918f651b22c99 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -105,6 +105,9 @@ static unsigned int max_physical_pkg_id __read_mostly;
 unsigned int __max_logical_packages __read_mostly;
 EXPORT_SYMBOL(__max_logical_packages);
 
+/* Maximum number of SMT threads on any online core */
+int __max_smt_threads __read_mostly;
+
 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
 {
        unsigned long flags;
@@ -493,7 +496,7 @@ void set_cpu_sibling_map(int cpu)
        bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
        struct cpuinfo_x86 *c = &cpu_data(cpu);
        struct cpuinfo_x86 *o;
-       int i;
+       int i, threads;
 
        cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
 
@@ -550,6 +553,10 @@ void set_cpu_sibling_map(int cpu)
                if (match_die(c, o) && !topology_same_node(c, o))
                        primarily_use_numa_for_topology();
        }
+
+       threads = cpumask_weight(topology_sibling_cpumask(cpu));
+       if (threads > __max_smt_threads)
+               __max_smt_threads = threads;
 }
 
 /* maps the cpu to the sched domain representing multi-core */
@@ -1236,7 +1243,7 @@ static int __init smp_sanity_check(unsigned max_cpus)
         * If we couldn't find a local APIC, then get out of here now!
         */
        if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
-           !cpu_has_apic) {
+           !boot_cpu_has(X86_FEATURE_APIC)) {
                if (!disable_apic) {
                        pr_err("BIOS bug, local APIC #%d not detected!...\n",
                                boot_cpu_physical_apicid);
@@ -1285,7 +1292,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
        cpumask_copy(cpu_callin_mask, cpumask_of(0));
        mb();
 
-       current_thread_info()->cpu = 0;  /* needed? */
        for_each_possible_cpu(i) {
                zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
                zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
@@ -1441,6 +1447,21 @@ __init void prefill_possible_map(void)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
+/* Recompute SMT state for all CPUs on offline */
+static void recompute_smt_state(void)
+{
+       int max_threads, cpu;
+
+       max_threads = 0;
+       for_each_online_cpu (cpu) {
+               int threads = cpumask_weight(topology_sibling_cpumask(cpu));
+
+               if (threads > max_threads)
+                       max_threads = threads;
+       }
+       __max_smt_threads = max_threads;
+}
+
 static void remove_siblinginfo(int cpu)
 {
        int sibling;
@@ -1465,6 +1486,7 @@ static void remove_siblinginfo(int cpu)
        c->phys_proc_id = 0;
        c->cpu_core_id = 0;
        cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
+       recompute_smt_state();
 }
 
 static void remove_cpu_from_maps(int cpu)