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()
  ...

arch/Kconfig

@@ -145,6 +145,21 @@ config HAVE_DMA_ATTRS
 config USE_GENERIC_SMP_HELPERS
 	bool
 
+config GENERIC_SMP_IDLE_THREAD
+       bool
+
+# Select if arch init_task initializer is different to init/init_task.c
+config ARCH_INIT_TASK
+       bool
+
+# Select if arch has its private alloc_task_struct() function
+config ARCH_TASK_STRUCT_ALLOCATOR
+	bool
+
+# Select if arch has its private alloc_thread_info() function
+config ARCH_THREAD_INFO_ALLOCATOR
+	bool
+
 config HAVE_REGS_AND_STACK_ACCESS_API
 	bool
 	help

arch/alpha/Kconfig

@@ -15,6 +15,7 @@ config ALPHA
 	select GENERIC_IRQ_SHOW
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
+	select GENERIC_SMP_IDLE_THREAD
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,

arch/alpha/kernel/Makefile

@@ -6,7 +6,7 @@ extra-y		:= head.o vmlinux.lds
 asflags-y	:= $(KBUILD_CFLAGS)
 ccflags-y	:= -Wno-sign-compare
 
-obj-y    := entry.o traps.o process.o init_task.o osf_sys.o irq.o \
+obj-y    := entry.o traps.o process.o osf_sys.o irq.o \
 	    irq_alpha.o signal.o setup.o ptrace.o time.o \
 	    alpha_ksyms.o systbls.o err_common.o io.o
 

arch/alpha/kernel/smp.c

@@ -357,24 +357,10 @@ secondary_cpu_start(int cpuid, struct task_struct *idle)
  * Bring one cpu online.
  */
 static int __cpuinit
-smp_boot_one_cpu(int cpuid)
+smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 {
-	struct task_struct *idle;
 	unsigned long timeout;
 
-	/* Cook up an idler for this guy.  Note that the address we
-	   give to kernel_thread is irrelevant -- it's going to start
-	   where HWRPB.CPU_restart says to start.  But this gets all
-	   the other task-y sort of data structures set up like we
-	   wish.  We can't use kernel_thread since we must avoid
-	   rescheduling the child.  */
-	idle = fork_idle(cpuid);
-	if (IS_ERR(idle))
-		panic("failed fork for CPU %d", cpuid);
-
-	DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
-	      cpuid, idle->state, idle->flags));
-
 	/* Signal the secondary to wait a moment.  */
 	smp_secondary_alive = -1;
 
@@ -487,9 +473,9 @@ smp_prepare_boot_cpu(void)
 }
 
 int __cpuinit
-__cpu_up(unsigned int cpu)
+__cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	smp_boot_one_cpu(cpu);
+	smp_boot_one_cpu(cpu, tidle);
 
 	return cpu_online(cpu) ? 0 : -ENOSYS;
 }

arch/arm/Kconfig

@@ -37,6 +37,7 @@ config ARM
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select GENERIC_PCI_IOMAP
 	select HAVE_BPF_JIT
+	select GENERIC_SMP_IDLE_THREAD
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and
@@ -154,9 +155,6 @@ config ARCH_HAS_CPUFREQ
 	  and that the relevant menu configurations are displayed for
 	  it.
 
-config ARCH_HAS_CPU_IDLE_WAIT
-       def_bool y
-
 config GENERIC_HWEIGHT
 	bool
 	default y

arch/arm/Makefile

@@ -117,7 +117,7 @@ KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_THUMB2) $(arch-y) $(tune-y) -include asm/
 CHECKFLAGS	+= -D__arm__
 
 #Default value
-head-y		:= arch/arm/kernel/head$(MMUEXT).o arch/arm/kernel/init_task.o
+head-y		:= arch/arm/kernel/head$(MMUEXT).o
 textofs-y	:= 0x00008000
 textofs-$(CONFIG_ARCH_CLPS711X) := 0x00028000
 # We don't want the htc bootloader to corrupt kernel during resume

arch/arm/include/asm/cpu.h

@@ -16,7 +16,6 @@
 struct cpuinfo_arm {
 	struct cpu	cpu;
 #ifdef CONFIG_SMP
-	struct task_struct *idle;
 	unsigned int	loops_per_jiffy;
 #endif
 };

arch/arm/include/asm/processor.h

@@ -88,8 +88,6 @@ unsigned long get_wchan(struct task_struct *p);
 #define cpu_relax()			barrier()
 #endif
 
-void cpu_idle_wait(void);
-
 /*
  * Create a new kernel thread
  */

arch/arm/kernel/Makefile

@@ -82,4 +82,4 @@ head-y			:= head$(MMUEXT).o
 obj-$(CONFIG_DEBUG_LL)	+= debug.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
-extra-y := $(head-y) init_task.o vmlinux.lds
+extra-y := $(head-y) vmlinux.lds

arch/arm/kernel/init_task.c

@@ -1,37 +0,0 @@
-/*
- *  linux/arch/arm/kernel/init_task.c
- */
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-#include <linux/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 8192-byte aligned due to the
- * way process stacks are handled. This is done by making sure
- * the linker maps this in the .text segment right after head.S,
- * and making head.S ensure the proper alignment.
- *
- * The things we do for performance..
- */
-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);

arch/arm/kernel/process.c

@@ -157,26 +157,6 @@ EXPORT_SYMBOL(pm_power_off);
 void (*arm_pm_restart)(char str, const char *cmd) = null_restart;
 EXPORT_SYMBOL_GPL(arm_pm_restart);
 
-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);
-
 /*
  * This is our default idle handler.
  */

arch/arm/kernel/smp.c

@@ -60,31 +60,10 @@ enum ipi_msg_type {
 
 static DECLARE_COMPLETION(cpu_running);
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
-	struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
-	struct task_struct *idle = ci->idle;
 	int ret;
 
-	/*
-	 * Spawn a new process manually, if not already done.
-	 * Grab a pointer to its task struct so we can mess with it
-	 */
-	if (!idle) {
-		idle = fork_idle(cpu);
-		if (IS_ERR(idle)) {
-			printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
-			return PTR_ERR(idle);
-		}
-		ci->idle = idle;
-	} else {
-		/*
-		 * Since this idle thread is being re-used, call
-		 * init_idle() to reinitialize the thread structure.
-		 */
-		init_idle(idle, cpu);
-	}
-
 	/*
 	 * We need to tell the secondary core where to find
 	 * its stack and the page tables.
@@ -318,9 +297,6 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 void __init smp_prepare_boot_cpu(void)
 {
-	unsigned int cpu = smp_processor_id();
-
-	per_cpu(cpu_data, cpu).idle = current;
 }
 
 void __init smp_prepare_cpus(unsigned int max_cpus)

arch/avr32/kernel/Makefile

@@ -8,7 +8,7 @@ obj-$(CONFIG_SUBARCH_AVR32B)	+= entry-avr32b.o
 obj-y				+= syscall_table.o syscall-stubs.o irq.o
 obj-y				+= setup.o traps.o ocd.o ptrace.o
 obj-y				+= signal.o sys_avr32.o process.o time.o
-obj-y				+= init_task.o switch_to.o cpu.o
+obj-y				+= switch_to.o cpu.o
 obj-$(CONFIG_MODULES)		+= module.o avr32_ksyms.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o

arch/avr32/kernel/init_task.c

@@ -1,31 +0,0 @@
-/*
- * Copyright (C) 2004-2006 Atmel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.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. Must be aligned on an 8192-byte boundary.
- */
-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);

arch/blackfin/Kconfig

@@ -37,6 +37,7 @@ config BLACKFIN
 	select GENERIC_IRQ_PROBE
 	select IRQ_PER_CPU if SMP
 	select HAVE_NMI_WATCHDOG if NMI_WATCHDOG
+	select GENERIC_SMP_IDLE_THREAD
 
 config GENERIC_CSUM
 	def_bool y

arch/blackfin/Makefile

@@ -109,8 +109,6 @@ KBUILD_AFLAGS += -mcpu=$(CPU_REV)
 CHECKFLAGS_SILICON = $(shell echo "" | $(CPP) $(KBUILD_CFLAGS) -dD - 2>/dev/null | awk '$$2 == "__SILICON_REVISION__" { print $$3 }')
 CHECKFLAGS += -D__SILICON_REVISION__=$(CHECKFLAGS_SILICON) -D__bfin__
 
-head-y   := arch/$(ARCH)/kernel/init_task.o
-
 core-y   += arch/$(ARCH)/kernel/ arch/$(ARCH)/mm/ arch/$(ARCH)/mach-common/
 
 # If we have a machine-specific directory, then include it in the build.

arch/blackfin/kernel/Makefile

@@ -2,7 +2,7 @@
 # arch/blackfin/kernel/Makefile
 #
 
-extra-y := init_task.o vmlinux.lds
+extra-y := vmlinux.lds
 
 obj-y := \
 	entry.o process.o bfin_ksyms.o ptrace.o setup.o signal.o \

arch/blackfin/kernel/init_task.c

@@ -1,32 +0,0 @@
-/*
- * Copyright 2004-2009 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later
- */
-
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-#include <linux/fs.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * 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);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte 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)};

arch/blackfin/mach-common/smp.c

@@ -340,27 +340,10 @@ void smp_send_stop(void)
 	return;
 }
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
 	int ret;
-	struct blackfin_cpudata *ci = &per_cpu(cpu_data, cpu);
-	struct task_struct *idle = ci->idle;
 
-	if (idle) {
-		free_task(idle);
-		idle = NULL;
-	}
-
-	if (!idle) {
-		idle = fork_idle(cpu);
-		if (IS_ERR(idle)) {
-			printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
-			return PTR_ERR(idle);
-		}
-		ci->idle = idle;
-	} else {
-		init_idle(idle, cpu);
-	}
 	secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 
 	ret = platform_boot_secondary(cpu, idle);

arch/c6x/include/asm/thread_info.h

@@ -20,11 +20,11 @@
 #ifdef CONFIG_4KSTACKS
 #define THREAD_SIZE		4096
 #define THREAD_SHIFT		12
-#define THREAD_ORDER		0
+#define THREAD_SIZE_ORDER	0
 #else
 #define THREAD_SIZE		8192
 #define THREAD_SHIFT		13
-#define THREAD_ORDER		1
+#define THREAD_SIZE_ORDER	1
 #endif
 
 #define THREAD_START_SP		(THREAD_SIZE - 8)
@@ -80,19 +80,6 @@ struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-/* thread information allocation */
-#ifdef CONFIG_DEBUG_STACK_USAGE
-#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
-#else
-#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
-#endif
-
-#define alloc_thread_info_node(tsk, node)	\
-	((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
-
-#define free_thread_info(ti)	free_pages((unsigned long) (ti), THREAD_ORDER)
 #define get_thread_info(ti)	get_task_struct((ti)->task)
 #define put_thread_info(ti)	put_task_struct((ti)->task)
 #endif /* __ASSEMBLY__ */