1 files changed, 44 insertions, 33 deletions

diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 91293388dd29..ebb71f3d6d19 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -3,6 +3,7 @@
  *
  * Copyright (C) 1998-2003 Hewlett-Packard Co
  *      David Mosberger-Tang <davidm@hpl.hp.com>
+ * 04/11/17 Ashok Raj   <ashok.raj@intel.com> Added CPU Hotplug Support
  */
 #define __KERNEL_SYSCALLS__     /* see <asm/unistd.h> */
 #include <linux/config.h>
@@ -49,7 +50,7 @@
 #include "sigframe.h"
 
 void (*ia64_mark_idle)(int);
-static cpumask_t cpu_idle_map;
+static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
 unsigned long boot_option_idle_override = 0;
 EXPORT_SYMBOL(boot_option_idle_override);
@@ -172,7 +173,9 @@ do_notify_resume_user (sigset_t *oldset, struct sigscratch *scr, long in_syscall
                 ia64_do_signal(oldset, scr, in_syscall);
 }
 
-static int pal_halt = 1;
+static int pal_halt        = 1;
+static int can_do_pal_halt = 1;
+
 static int __init nohalt_setup(char * str)
 {
         pal_halt = 0;
@@ -180,16 +183,20 @@ static int __init nohalt_setup(char * str)
 }
 __setup("nohalt", nohalt_setup);
 
+void
+update_pal_halt_status(int status)
+{
+        can_do_pal_halt = pal_halt && status;
+}
+
 /*
  * We use this if we don't have any better idle routine..
  */
 void
 default_idle (void)
 {
-        unsigned long pmu_active = ia64_getreg(_IA64_REG_PSR) & (IA64_PSR_PP | IA64_PSR_UP);
-
         while (!need_resched())
-                if (pal_halt && !pmu_active)
+                if (can_do_pal_halt)
                         safe_halt();
                 else
                         cpu_relax();
@@ -200,27 +207,20 @@ default_idle (void)
 static inline void play_dead(void)
 {
         extern void ia64_cpu_local_tick (void);
+        unsigned int this_cpu = smp_processor_id();
+
         /* Ack it */
         __get_cpu_var(cpu_state) = CPU_DEAD;
 
-        /* We shouldn't have to disable interrupts while dead, but
-         * some interrupts just don't seem to go away, and this makes
-         * it "work" for testing purposes. */
         max_xtp();
         local_irq_disable();
-        /* Death loop */
-        while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
-                cpu_relax();
-
+        idle_task_exit();
+        ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
         /*
-         * Enable timer interrupts from now on
-         * Not required if we put processor in SAL_BOOT_RENDEZ mode.
+         * The above is a point of no-return, the processor is
+         * expected to be in SAL loop now.
          */
-        local_flush_tlb_all();
-        cpu_set(smp_processor_id(), cpu_online_map);
-        wmb();
-        ia64_cpu_local_tick ();
-        local_irq_enable();
+        BUG();
 }
 #else
 static inline void play_dead(void)
@@ -229,20 +229,31 @@ static inline void play_dead(void)
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
-
 void cpu_idle_wait(void)
 {
-        int cpu;
-        cpumask_t map;
+        unsigned int cpu, this_cpu = get_cpu();
+        cpumask_t map;
+
+        set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
+        put_cpu();
 
-        for_each_online_cpu(cpu)
-                cpu_set(cpu, cpu_idle_map);
+        cpus_clear(map);
+        for_each_online_cpu(cpu) {
+                per_cpu(cpu_idle_state, cpu) = 1;
+                cpu_set(cpu, map);
+        }
 
-        wmb();
-        do {
-                ssleep(1);
-                cpus_and(map, cpu_idle_map, cpu_online_map);
-        } while (!cpus_empty(map));
+        __get_cpu_var(cpu_idle_state) = 0;
+
+        wmb();
+        do {
+                ssleep(1);
+                for_each_online_cpu(cpu) {
+                        if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
+                                cpu_clear(cpu, map);
+                }
+                cpus_and(map, map, cpu_online_map);
+        } while (!cpus_empty(map));
 }
 EXPORT_SYMBOL_GPL(cpu_idle_wait);
 
@@ -250,7 +261,6 @@ void __attribute__((noreturn))
 cpu_idle (void)
 {
         void (*mark_idle)(int) = ia64_mark_idle;
-        int cpu = smp_processor_id();
 
         /* endless idle loop with no priority at all */
         while (1) {
@@ -261,12 +271,13 @@ cpu_idle (void)
                 while (!need_resched()) {
                         void (*idle)(void);
 
+                        if (__get_cpu_var(cpu_idle_state))
+                                __get_cpu_var(cpu_idle_state) = 0;
+
+                        rmb();
                         if (mark_idle)
                                 (*mark_idle)(1);
 
-                        if (cpu_isset(cpu, cpu_idle_map))
-                                cpu_clear(cpu, cpu_idle_map);
-                        rmb();
                         idle = pm_idle;
                         if (!idle)
                                 idle = default_idle;