Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp hotplug cleanups from Thomas Gleixner:
 "This series is merily a cleanup of code copied around in arch/* and
  not changing any of the real cpu hotplug horrors yet.  I wish I'd had
  something more substantial for 3.5, but I underestimated the lurking
  horror..."

Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
arch/sparc/include/asm/thread_info_32.h

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
  um: Remove leftover declaration of alloc_task_struct_node()
  task_allocator: Use config switches instead of magic defines
  sparc: Use common threadinfo allocator
  score: Use common threadinfo allocator
  sh-use-common-threadinfo-allocator
  mn10300: Use common threadinfo allocator
  powerpc: Use common threadinfo allocator
  mips: Use common threadinfo allocator
  hexagon: Use common threadinfo allocator
  m32r: Use common threadinfo allocator
  frv: Use common threadinfo allocator
  cris: Use common threadinfo allocator
  x86: Use common threadinfo allocator
  c6x: Use common threadinfo allocator
  fork: Provide kmemcache based thread_info allocator
  tile: Use common threadinfo allocator
  fork: Provide weak arch_release_[task_struct|thread_info] functions
  fork: Move thread info gfp flags to header
  fork: Remove the weak insanity
  sh: Remove cpu_idle_wait()
  ...

5 files changed, 8 insertions, 83 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index bd7266903bf8..ba667b60f32d 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -33,6 +33,10 @@ config IA64
         select ARCH_WANT_OPTIONAL_GPIOLIB
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
         select GENERIC_IOMAP
+        select GENERIC_SMP_IDLE_THREAD
+        select ARCH_INIT_TASK
+        select ARCH_TASK_STRUCT_ALLOCATOR
+        select ARCH_THREAD_INFO_ALLOCATOR
         default y
         help
           The Itanium Processor Family is Intel's 64-bit successor to
diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h
index 483f6c6a4238..f92f67aba618 100644
--- a/arch/ia64/include/asm/processor.h
+++ b/arch/ia64/include/asm/processor.h
@@ -723,7 +723,6 @@ extern unsigned long boot_option_idle_override;
 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_FORCE_MWAIT,
                          IDLE_NOMWAIT, IDLE_POLL};
 
-void cpu_idle_wait(void);
 void default_idle(void);
 
 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)
diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index e054bcc4273c..310d9734f02d 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -54,8 +54,6 @@ struct thread_info {
         },                                      \
 }
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
 #ifndef ASM_OFFSETS_C
 /* how to get the thread information struct from C */
 #define current_thread_info()   ((struct thread_info *) ((char *) current + IA64_TASK_SIZE))
@@ -84,7 +82,6 @@ struct thread_info {
 #endif
 #define end_of_stack(p) (unsigned long *)((void *)(p) + IA64_RBS_OFFSET)
 
-#define __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
 #define alloc_task_struct_node(node)                                            \
 ({                                                                              \
         struct page *page = alloc_pages_node(node, GFP_KERNEL | __GFP_COMP,     \
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index ce74e143aea3..5e0e86ddb12f 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -273,26 +273,6 @@ static inline void play_dead(void)
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static void do_nothing(void *unused)
-{
-}
-
-/*
- * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
- * pm_idle and update to new pm_idle value. Required while changing pm_idle
- * handler on SMP systems.
- *
- * Caller must have changed pm_idle to the new value before the call. Old
- * pm_idle value will not be used by any CPU after the return of this function.
- */
-void cpu_idle_wait(void)
-{
-        smp_mb();
-        /* kick all the CPUs so that they exit out of pm_idle */
-        smp_call_function(do_nothing, NULL, 1);
-}
-EXPORT_SYMBOL_GPL(cpu_idle_wait);
-
 void __attribute__((noreturn))
 cpu_idle (void)
 {
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index 796f6a5b966a..1113b8aba07f 100644
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -75,13 +75,6 @@
 #endif
 
 /*
- * Store all idle threads, this can be reused instead of creating
- * a new thread. Also avoids complicated thread destroy functionality
- * for idle threads.
- */
-struct task_struct *idle_thread_array[NR_CPUS];
-
-/*
  * Global array allocated for NR_CPUS at boot time
  */
 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
@@ -94,13 +87,7 @@ struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
 
 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
 
-#define get_idle_for_cpu(x)             (idle_thread_array[(x)])
-#define set_idle_for_cpu(x,p)   (idle_thread_array[(x)] = (p))
-
 #else
-
-#define get_idle_for_cpu(x)             (NULL)
-#define set_idle_for_cpu(x,p)
 #define set_brendez_area(x)
 #endif
 
@@ -480,54 +467,12 @@ struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
         return NULL;
 }
 
-struct create_idle {
-        struct work_struct work;
-        struct task_struct *idle;
-        struct completion done;
-        int cpu;
-};
-
-void __cpuinit
-do_fork_idle(struct work_struct *work)
-{
-        struct create_idle *c_idle =
-                container_of(work, struct create_idle, work);
-
-        c_idle->idle = fork_idle(c_idle->cpu);
-        complete(&c_idle->done);
-}
-
 static int __cpuinit
-do_boot_cpu (int sapicid, int cpu)
+do_boot_cpu (int sapicid, int cpu, struct task_struct *idle)
 {
         int timeout;
-        struct create_idle c_idle = {
-                .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
-                .cpu    = cpu,
-                .done   = COMPLETION_INITIALIZER(c_idle.done),
-        };
-
-        /*
-         * We can't use kernel_thread since we must avoid to
-         * reschedule the child.
-         */
-        c_idle.idle = get_idle_for_cpu(cpu);
-        if (c_idle.idle) {
-                init_idle(c_idle.idle, cpu);
-                goto do_rest;
-        }
-
-        schedule_work(&c_idle.work);
-        wait_for_completion(&c_idle.done);
-
-        if (IS_ERR(c_idle.idle))
-                panic("failed fork for CPU %d", cpu);
-
-        set_idle_for_cpu(cpu, c_idle.idle);
-
-do_rest:
-        task_for_booting_cpu = c_idle.idle;
 
+        task_for_booting_cpu = idle;
         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 
         set_brendez_area(cpu);
@@ -793,7 +738,7 @@ set_cpu_sibling_map(int cpu)
 }
 
 int __cpuinit
-__cpu_up (unsigned int cpu)
+__cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
         int ret;
         int sapicid;
@@ -811,7 +756,7 @@ __cpu_up (unsigned int cpu)
 
         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
         /* Processor goes to start_secondary(), sets online flag */
-        ret = do_boot_cpu(sapicid, cpu);
+        ret = do_boot_cpu(sapicid, cpu, tidle);
         if (ret < 0)
                 return ret;