1 files changed, 90 insertions, 19 deletions

diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index a32a882a2d58..7dbd92cafae3 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -30,6 +30,7 @@
 #include <linux/ftrace.h>
 #include <linux/cpu.h>
 #include <linux/kgdb.h>
+#include <linux/sched/hotplug.h>
 
 #include <linux/atomic.h>
 #include <asm/current.h>
@@ -60,8 +61,6 @@ volatile struct task_struct *smp_init_current_idle_task;
 /* track which CPU is booting */
 static volatile int cpu_now_booting;
 
-static int parisc_max_cpus = 1;
-
 static DEFINE_PER_CPU(spinlock_t, ipi_lock);
 
 enum ipi_message_type {
@@ -269,7 +268,7 @@ void arch_send_call_function_single_ipi(int cpu)
 /*
  * Called by secondaries to update state and initialize CPU registers.
  */
-static void __init
+static void
 smp_cpu_init(int cpunum)
 {
 	extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */
@@ -309,7 +308,7 @@ smp_cpu_init(int cpunum)
  * Slaves start using C here. Indirectly called from smp_slave_stext.
  * Do what start_kernel() and main() do for boot strap processor (aka monarch)
  */
-void __init smp_callin(unsigned long pdce_proc)
+void smp_callin(unsigned long pdce_proc)
 {
 	int slave_id = cpu_now_booting;
 
@@ -334,11 +333,28 @@ void __init smp_callin(unsigned long pdce_proc)
 /*
  * Bring one cpu online.
  */
-int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
+static int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 {
 	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
 	long timeout;
 
+#ifdef CONFIG_HOTPLUG_CPU
+	int i;
+
+	/* reset irq statistics for this CPU */
+	memset(&per_cpu(irq_stat, cpuid), 0, sizeof(irq_cpustat_t));
+	for (i = 0; i < NR_IRQS; i++) {
+		struct irq_desc *desc = irq_to_desc(i);
+
+		if (desc && desc->kstat_irqs)
+			*per_cpu_ptr(desc->kstat_irqs, cpuid) = 0;
+	}
+#endif
+
+	/* wait until last booting CPU has started. */
+	while (cpu_now_booting)
+		;
+
 	/* Let _start know what logical CPU we're booting
 	** (offset into init_tasks[],cpu_data[])
 	*/
@@ -374,7 +390,6 @@ int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 		if(cpu_online(cpuid)) {
 			/* Which implies Slave has started up */
 			cpu_now_booting = 0;
-			smp_init_current_idle_task = NULL;
 			goto alive ;
 		}
 		udelay(100);
@@ -415,30 +430,86 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 		spin_lock_init(&per_cpu(ipi_lock, cpu));
 
 	init_cpu_present(cpumask_of(0));
-
-	parisc_max_cpus = max_cpus;
-	if (!max_cpus)
-		printk(KERN_INFO "SMP mode deactivated.\n");
 }
 
 
-void smp_cpus_done(unsigned int cpu_max)
+void __init smp_cpus_done(unsigned int cpu_max)
 {
-	return;
 }
 
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	if (cpu != 0 && cpu < parisc_max_cpus && smp_boot_one_cpu(cpu, tidle))
-		return -ENOSYS;
+	if (cpu_online(cpu))
+		return 0;
+
+	if (num_online_cpus() < setup_max_cpus && smp_boot_one_cpu(cpu, tidle))
+		return -EIO;
 
-	return cpu_online(cpu) ? 0 : -ENOSYS;
+	return cpu_online(cpu) ? 0 : -EIO;
 }
 
-#ifdef CONFIG_PROC_FS
-int setup_profiling_timer(unsigned int multiplier)
+/*
+ * __cpu_disable runs on the processor to be shutdown.
+ */
+int __cpu_disable(void)
 {
-	return -EINVAL;
-}
+#ifdef CONFIG_HOTPLUG_CPU
+	unsigned int cpu = smp_processor_id();
+
+	remove_cpu_topology(cpu);
+
+	/*
+	 * Take this CPU offline.  Once we clear this, we can't return,
+	 * and we must not schedule until we're ready to give up the cpu.
+	 */
+	set_cpu_online(cpu, false);
+
+	/* Find a new timesync master */
+	if (cpu == time_keeper_id) {
+		time_keeper_id = cpumask_first(cpu_online_mask);
+		pr_info("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
+	}
+
+	disable_percpu_irq(IPI_IRQ);
+
+	irq_migrate_all_off_this_cpu();
+
+	flush_cache_all_local();
+	flush_tlb_all_local(NULL);
+
+	/* disable all irqs, including timer irq */
+	local_irq_disable();
+
+	/* wait for next timer irq ... */
+	mdelay(1000/HZ+100);
+
+	/* ... and then clear all pending external irqs */
+	set_eiem(0);
+	mtctl(~0UL, CR_EIRR);
+	mfctl(CR_EIRR);
+	mtctl(0, CR_EIRR);
 #endif
+	return 0;
+}
+
+/*
+ * called on the thread which is asking for a CPU to be shutdown -
+ * waits until shutdown has completed, or it is timed out.
+ */
+void __cpu_die(unsigned int cpu)
+{
+	pdc_cpu_rendezvous_lock();
+
+	if (!cpu_wait_death(cpu, 5)) {
+		pr_crit("CPU%u: cpu didn't die\n", cpu);
+		return;
+	}
+	pr_info("CPU%u: is shutting down\n", cpu);
+
+	/* set task's state to interruptible sleep */
+	set_current_state(TASK_INTERRUPTIBLE);
+	schedule_timeout((IS_ENABLED(CONFIG_64BIT) ? 8:2) * HZ);
+
+	pdc_cpu_rendezvous_unlock();
+}