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()
  ...

6 files changed, 6 insertions, 73 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b42f2866594b..e16390c0bca8 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -122,6 +122,7 @@ config S390
         select ARCH_INLINE_WRITE_UNLOCK_BH
         select ARCH_INLINE_WRITE_UNLOCK_IRQ
         select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+        select GENERIC_SMP_IDLE_THREAD
 
 config SCHED_OMIT_FRAME_POINTER
         def_bool y
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 0ad2f1e1ce9e..49e76e8b477d 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -91,7 +91,6 @@ OBJCOPYFLAGS	:= -O binary
 
 head-y          := arch/s390/kernel/head.o
 head-y          += arch/s390/kernel/$(if $(CONFIG_64BIT),head64.o,head31.o)
-head-y          += arch/s390/kernel/init_task.o
 
 # See arch/s390/Kbuild for content of core part of the kernel
 core-y          += arch/s390/
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index c77c6de6f6c0..0b6f586c1383 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -16,7 +16,7 @@
 extern struct mutex smp_cpu_state_mutex;
 extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 
-extern int __cpu_up(unsigned int cpu);
+extern int __cpu_up(unsigned int cpu, struct task_struct *tidle);
 
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 884b18afc864..9733b3f0eb6d 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -28,7 +28,7 @@ obj-y	:=  bitmap.o traps.o time.o process.o base.o early.o setup.o vtime.o \
 obj-y   += $(if $(CONFIG_64BIT),entry64.o,entry.o)
 obj-y   += $(if $(CONFIG_64BIT),reipl64.o,reipl.o)
 
-extra-y                         += head.o init_task.o vmlinux.lds
+extra-y                         += head.o vmlinux.lds
 extra-y                         += $(if $(CONFIG_64BIT),head64.o,head31.o)
 
 obj-$(CONFIG_MODULES)           += s390_ksyms.o module.o
diff --git a/arch/s390/kernel/init_task.c b/arch/s390/kernel/init_task.c
deleted file mode 100644
index 4d1c9fb0b540..000000000000
--- a/arch/s390/kernel/init_task.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- *  arch/s390/kernel/init_task.c
- *
- *  S390 version
- *
- *  Derived from "arch/i386/kernel/init_task.c"
- */
-
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-        { INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index e505458c6899..647ba9425893 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -85,7 +85,6 @@ enum {
 
 struct pcpu {
         struct cpu cpu;
-        struct task_struct *idle;       /* idle process for the cpu */
         struct _lowcore *lowcore;       /* lowcore page(s) for the cpu */
         unsigned long async_stack;      /* async stack for the cpu */
         unsigned long panic_stack;      /* panic stack for the cpu */
@@ -725,26 +724,9 @@ static void __cpuinit smp_start_secondary(void *cpuvoid)
         cpu_idle();
 }
 
-struct create_idle {
-        struct work_struct work;
-        struct task_struct *idle;
-        struct completion done;
-        int cpu;
-};
-
-static void __cpuinit smp_fork_idle(struct work_struct *work)
-{
-        struct create_idle *c_idle;
-
-        c_idle = container_of(work, struct create_idle, work);
-        c_idle->idle = fork_idle(c_idle->cpu);
-        complete(&c_idle->done);
-}
-
 /* Upping and downing of CPUs */
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-        struct create_idle c_idle;
         struct pcpu *pcpu;
         int rc;
 
@@ -754,22 +736,12 @@ int __cpuinit __cpu_up(unsigned int cpu)
         if (pcpu_sigp_retry(pcpu, sigp_initial_cpu_reset, 0) !=
             sigp_order_code_accepted)
                 return -EIO;
-        if (!pcpu->idle) {
-                c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
-                INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
-                c_idle.cpu = cpu;
-                schedule_work(&c_idle.work);
-                wait_for_completion(&c_idle.done);
-                if (IS_ERR(c_idle.idle))
-                        return PTR_ERR(c_idle.idle);
-                pcpu->idle = c_idle.idle;
-        }
-        init_idle(pcpu->idle, cpu);
+
         rc = pcpu_alloc_lowcore(pcpu, cpu);
         if (rc)
                 return rc;
         pcpu_prepare_secondary(pcpu, cpu);
-        pcpu_attach_task(pcpu, pcpu->idle);
+        pcpu_attach_task(pcpu, tidle);
         pcpu_start_fn(pcpu, smp_start_secondary, NULL);
         while (!cpu_online(cpu))
                 cpu_relax();
@@ -856,7 +828,6 @@ void __init smp_prepare_boot_cpu(void)
         struct pcpu *pcpu = pcpu_devices;
 
         boot_cpu_address = stap();
-        pcpu->idle = current;
         pcpu->state = CPU_STATE_CONFIGURED;
         pcpu->address = boot_cpu_address;
         pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();