4 files changed, 44 insertions, 45 deletions

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index d2b12988d2ed..bf2caa1dedc5 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -34,8 +34,6 @@ extern int _debug_hotplug_cpu(int cpu, int action);
 #endif
 #endif
 
-DECLARE_PER_CPU(int, cpu_state);
-
 int mwait_usable(const struct cpuinfo_x86 *);
 
 #endif /* _ASM_X86_CPU_H */
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 8cd1cc3bc835..a5cb4f6e9492 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -150,12 +150,12 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 }
 
 void cpu_disable_common(void);
-void cpu_die_common(unsigned int cpu);
 void native_smp_prepare_boot_cpu(void);
 void native_smp_prepare_cpus(unsigned int max_cpus);
 void native_smp_cpus_done(unsigned int max_cpus);
 int native_cpu_up(unsigned int cpunum, struct task_struct *tidle);
 int native_cpu_disable(void);
+int common_cpu_die(unsigned int cpu);
 void native_cpu_die(unsigned int cpu);
 void native_play_dead(void);
 void play_dead_common(void);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index febc6aabc72e..c8fa34963ead 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -77,9 +77,6 @@
 #include <asm/realmode.h>
 #include <asm/misc.h>
 
-/* State of each CPU */
-DEFINE_PER_CPU(int, cpu_state) = { 0 };
-
 /* Number of siblings per CPU package */
 int smp_num_siblings = 1;
 EXPORT_SYMBOL(smp_num_siblings);
@@ -257,7 +254,7 @@ static void notrace start_secondary(void *unused)
         lock_vector_lock();
         set_cpu_online(smp_processor_id(), true);
         unlock_vector_lock();
-        per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
+        cpu_set_state_online(smp_processor_id());
         x86_platform.nmi_init();
 
         /* enable local interrupts */
@@ -948,7 +945,10 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle)
          */
         mtrr_save_state();
 
-        per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+        /* x86 CPUs take themselves offline, so delayed offline is OK. */
+        err = cpu_check_up_prepare(cpu);
+        if (err && err != -EBUSY)
+                return err;
 
         /* the FPU context is blank, nobody can own it */
         __cpu_disable_lazy_restore(cpu);
@@ -1191,7 +1191,7 @@ void __init native_smp_prepare_boot_cpu(void)
         switch_to_new_gdt(me);
         /* already set me in cpu_online_mask in boot_cpu_init() */
         cpumask_set_cpu(me, cpu_callout_mask);
-        per_cpu(cpu_state, me) = CPU_ONLINE;
+        cpu_set_state_online(me);
 }
 
 void __init native_smp_cpus_done(unsigned int max_cpus)
@@ -1318,14 +1318,10 @@ static void __ref remove_cpu_from_maps(int cpu)
         numa_remove_cpu(cpu);
 }
 
-static DEFINE_PER_CPU(struct completion, die_complete);
-
 void cpu_disable_common(void)
 {
         int cpu = smp_processor_id();
 
-        init_completion(&per_cpu(die_complete, smp_processor_id()));
-
         remove_siblinginfo(cpu);
 
         /* It's now safe to remove this processor from the online map */
@@ -1349,24 +1345,27 @@ int native_cpu_disable(void)
         return 0;
 }
 
-void cpu_die_common(unsigned int cpu)
+int common_cpu_die(unsigned int cpu)
 {
-        wait_for_completion_timeout(&per_cpu(die_complete, cpu), HZ);
-}
+        int ret = 0;
 
-void native_cpu_die(unsigned int cpu)
-{
         /* We don't do anything here: idle task is faking death itself. */
 
-        cpu_die_common(cpu);
-
         /* They ack this in play_dead() by setting CPU_DEAD */
-        if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
+        if (cpu_wait_death(cpu, 5)) {
                 if (system_state == SYSTEM_RUNNING)
                         pr_info("CPU %u is now offline\n", cpu);
         } else {
                 pr_err("CPU %u didn't die...\n", cpu);
+                ret = -1;
         }
+
+        return ret;
+}
+
+void native_cpu_die(unsigned int cpu)
+{
+        common_cpu_die(cpu);
 }
 
 void play_dead_common(void)
@@ -1375,10 +1374,8 @@ void play_dead_common(void)
         reset_lazy_tlbstate();
         amd_e400_remove_cpu(raw_smp_processor_id());
 
-        mb();
         /* Ack it */
-        __this_cpu_write(cpu_state, CPU_DEAD);
-        complete(&per_cpu(die_complete, smp_processor_id()));
+        (void)cpu_report_death();
 
         /*
          * With physical CPU hotplug, we should halt the cpu
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 08e8489c47f1..1c5e760f34ca 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -90,14 +90,10 @@ static void cpu_bringup(void)
 
         set_cpu_online(cpu, true);
 
-        this_cpu_write(cpu_state, CPU_ONLINE);
-
-        wmb();
+        cpu_set_state_online(cpu);  /* Implies full memory barrier. */
 
         /* We can take interrupts now: we're officially "up". */
         local_irq_enable();
-
-        wmb();                  /* make sure everything is out */
 }
 
 /*
@@ -459,7 +455,13 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
         xen_setup_timer(cpu);
         xen_init_lock_cpu(cpu);
 
-        per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+        /*
+         * PV VCPUs are always successfully taken down (see 'while' loop
+         * in xen_cpu_die()), so -EBUSY is an error.
+         */
+        rc = cpu_check_up_prepare(cpu);
+        if (rc)
+                return rc;
 
         /* make sure interrupts start blocked */
         per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
@@ -479,10 +481,8 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
         rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
         BUG_ON(rc);
 
-        while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
+        while (cpu_report_state(cpu) != CPU_ONLINE)
                 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
-                barrier();
-        }
 
         return 0;
 }
@@ -511,11 +511,11 @@ static void xen_cpu_die(unsigned int cpu)
                 schedule_timeout(HZ/10);
         }
 
-        cpu_die_common(cpu);
-
-        xen_smp_intr_free(cpu);
-        xen_uninit_lock_cpu(cpu);
-        xen_teardown_timer(cpu);
+        if (common_cpu_die(cpu) == 0) {
+                xen_smp_intr_free(cpu);
+                xen_uninit_lock_cpu(cpu);
+                xen_teardown_timer(cpu);
+        }
 }
 
 static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
@@ -747,6 +747,16 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
 static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
         int rc;
+
+        /*
+         * This can happen if CPU was offlined earlier and
+         * offlining timed out in common_cpu_die().
+         */
+        if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
+                xen_smp_intr_free(cpu);
+                xen_uninit_lock_cpu(cpu);
+        }
+
         /*
          * xen_smp_intr_init() needs to run before native_cpu_up()
          * so that IPI vectors are set up on the booting CPU before
@@ -768,12 +778,6 @@ static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
         return rc;
 }
 
-static void xen_hvm_cpu_die(unsigned int cpu)
-{
-        xen_cpu_die(cpu);
-        native_cpu_die(cpu);
-}
-
 void __init xen_hvm_smp_init(void)
 {
         if (!xen_have_vector_callback)
@@ -781,7 +785,7 @@ void __init xen_hvm_smp_init(void)
         smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
         smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
         smp_ops.cpu_up = xen_hvm_cpu_up;
-        smp_ops.cpu_die = xen_hvm_cpu_die;
+        smp_ops.cpu_die = xen_cpu_die;
         smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
         smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
         smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu;