[PATCH] x86_64: CPU hotplug sibling map cleanup

This patch is a minor cleanup to the cpu sibling/core map.  It is required
that this setup happens on a per-cpu bringup time.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 36 insertions, 48 deletions

diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 5a3f955b6576..571a55462fa0 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -445,6 +445,33 @@ void __cpuinit smp_callin(void)
         cpu_set(cpuid, cpu_callin_map);
 }
 
+static inline void set_cpu_sibling_map(int cpu)
+{
+        int i;
+
+        if (smp_num_siblings > 1) {
+                for_each_cpu(i) {
+                        if (cpu_core_id[cpu] == cpu_core_id[i]) {
+                                cpu_set(i, cpu_sibling_map[cpu]);
+                                cpu_set(cpu, cpu_sibling_map[i]);
+                        }
+                }
+        } else {
+                cpu_set(cpu, cpu_sibling_map[cpu]);
+        }
+
+        if (current_cpu_data.x86_num_cores > 1) {
+                for_each_cpu(i) {
+                        if (phys_proc_id[cpu] == phys_proc_id[i]) {
+                                cpu_set(i, cpu_core_map[cpu]);
+                                cpu_set(cpu, cpu_core_map[i]);
+                        }
+                }
+        } else {
+                cpu_core_map[cpu] = cpu_sibling_map[cpu];
+        }
+}
+
 /*
  * Setup code on secondary processor (after comming out of the trampoline)
  */
@@ -475,6 +502,12 @@ void __cpuinit start_secondary(void)
         enable_APIC_timer();
 
         /*
+         * The sibling maps must be set before turing the online map on for
+         * this cpu
+         */
+        set_cpu_sibling_map(smp_processor_id());
+
+        /*
          * Allow the master to continue.
          */
         cpu_set(smp_processor_id(), cpu_online_map);
@@ -817,51 +850,6 @@ cycles_t cacheflush_time;
 unsigned long cache_decay_ticks;
 
 /*
- * Construct cpu_sibling_map[], so that we can tell the sibling CPU
- * on SMT systems efficiently.
- */
-static __cpuinit void detect_siblings(void)
-{
-        int cpu;
-
-        for (cpu = 0; cpu < NR_CPUS; cpu++) {
-                cpus_clear(cpu_sibling_map[cpu]);
-                cpus_clear(cpu_core_map[cpu]);
-        }
-
-        for_each_online_cpu (cpu) {
-                struct cpuinfo_x86 *c = cpu_data + cpu;
-                int siblings = 0;
-                int i;
-                if (smp_num_siblings > 1) {
-                        for_each_online_cpu (i) {
-                                if (cpu_core_id[cpu] == cpu_core_id[i]) {
-                                        siblings++;
-                                        cpu_set(i, cpu_sibling_map[cpu]);
-                                }
-                        }
-                } else {
-                        siblings++;
-                        cpu_set(cpu, cpu_sibling_map[cpu]);
-                }
-
-                if (siblings != smp_num_siblings) {
-                        printk(KERN_WARNING
-               "WARNING: %d siblings found for CPU%d, should be %d\n",
-                               siblings, cpu, smp_num_siblings);
-                        smp_num_siblings = siblings;
-                }
-                if (c->x86_num_cores > 1) {
-                        for_each_online_cpu(i) {
-                                if (phys_proc_id[cpu] == phys_proc_id[i])
-                                        cpu_set(i, cpu_core_map[cpu]);
-                        }
-                } else
-                        cpu_core_map[cpu] = cpu_sibling_map[cpu];
-        }
-}
-
-/*
  * Cleanup possible dangling ends...
  */
 static __cpuinit void smp_cleanup_boot(void)
@@ -1048,6 +1036,8 @@ void __init smp_prepare_boot_cpu(void)
         int me = smp_processor_id();
         cpu_set(me, cpu_online_map);
         cpu_set(me, cpu_callout_map);
+        cpu_set(0, cpu_sibling_map[0]);
+        cpu_set(0, cpu_core_map[0]);
 }
 
 /*
@@ -1107,7 +1097,6 @@ void __init smp_cpus_done(unsigned int max_cpus)
         setup_ioapic_dest();
 #endif
 
-        detect_siblings();
         time_init_gtod();
 
         check_nmi_watchdog();
@@ -1115,8 +1104,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-static void
-remove_siblinginfo(int cpu)
+static void remove_siblinginfo(int cpu)
 {
         int sibling;