1 files changed, 112 insertions, 312 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 15763af7bfe..4505e2a950d 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -1,3 +1,5 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
@@ -12,20 +14,54 @@
 #include <linux/user-return-notifier.h>
 #include <linux/dmi.h>
 #include <linux/utsname.h>
+#include <linux/stackprotector.h>
+#include <linux/tick.h>
+#include <linux/cpuidle.h>
 #include <trace/events/power.h>
 #include <linux/hw_breakpoint.h>
 #include <asm/cpu.h>
-#include <asm/system.h>
 #include <asm/apic.h>
 #include <asm/syscalls.h>
 #include <asm/idle.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include <asm/fpu-internal.h>
 #include <asm/debugreg.h>
+#include <asm/nmi.h>
+
+/*
+ * per-CPU TSS segments. Threads are completely 'soft' on Linux,
+ * no more per-task TSS's. The TSS size is kept cacheline-aligned
+ * so they are allowed to end up in the .data..cacheline_aligned
+ * section. Since TSS's are completely CPU-local, we want them
+ * on exact cacheline boundaries, to eliminate cacheline ping-pong.
+ */
+__visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, init_tss) = INIT_TSS;
+
+#ifdef CONFIG_X86_64
+static DEFINE_PER_CPU(unsigned char, is_idle);
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+void idle_notifier_register(struct notifier_block *n)
+{
+	atomic_notifier_chain_register(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+	atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_unregister);
+#endif
 
 struct kmem_cache *task_xstate_cachep;
 EXPORT_SYMBOL_GPL(task_xstate_cachep);
 
+/*
+ * this gets called so that we can store lazy state into memory and copy the
+ * current task into the new thread.
+ */
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
 	int ret;
@@ -36,7 +72,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 		ret = fpu_alloc(&dst->thread.fpu);
 		if (ret)
 			return ret;
-		fpu_copy(&dst->thread.fpu, &src->thread.fpu);
+		fpu_copy(dst, src);
 	}
 	return 0;
 }
@@ -46,10 +82,9 @@ void free_thread_xstate(struct task_struct *tsk)
 	fpu_free(&tsk->thread.fpu);
 }
 
-void free_thread_info(struct thread_info *ti)
+void arch_release_task_struct(struct task_struct *tsk)
 {
-	free_thread_xstate(ti->task);
-	free_pages((unsigned long)ti, THREAD_ORDER);
+	free_thread_xstate(tsk);
 }
 
 void arch_task_cache_init(void)
@@ -82,38 +117,8 @@ void exit_thread(void)
 		put_cpu();
 		kfree(bp);
 	}
-}
-
-void show_regs(struct pt_regs *regs)
-{
-	show_registers(regs);
-	show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs), 0);
-}
-
-void show_regs_common(void)
-{
-	const char *vendor, *product, *board;
-
-	vendor = dmi_get_system_info(DMI_SYS_VENDOR);
-	if (!vendor)
-		vendor = "";
-	product = dmi_get_system_info(DMI_PRODUCT_NAME);
-	if (!product)
-		product = "";
 
-	/* Board Name is optional */
-	board = dmi_get_system_info(DMI_BOARD_NAME);
-
-	printk(KERN_CONT "\n");
-	printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s",
-		current->pid, current->comm, print_tainted(),
-		init_utsname()->release,
-		(int)strcspn(init_utsname()->version, " "),
-		init_utsname()->version);
-	printk(KERN_CONT " %s %s", vendor, product);
-	if (board)
-		printk(KERN_CONT "/%s", board);
-	printk(KERN_CONT "\n");
+	drop_fpu(me);
 }
 
 void flush_thread(void)
@@ -122,12 +127,13 @@ void flush_thread(void)
 
 	flush_ptrace_hw_breakpoint(tsk);
 	memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
+	drop_init_fpu(tsk);
 	/*
-	 * Forget coprocessor state..
+	 * Free the FPU state for non xsave platforms. They get reallocated
+	 * lazily at the first use.
 	 */
-	tsk->fpu_counter = 0;
-	clear_fpu(tsk);
-	clear_used_math();
+	if (!use_eager_fpu())
+		free_thread_xstate(tsk);
 }
 
 static void hard_disable_TSC(void)
@@ -232,185 +238,92 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
 	propagate_user_return_notify(prev_p, next_p);
 }
 
-int sys_fork(struct pt_regs *regs)
-{
-	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-}
-
 /*
- * This is trivial, and on the face of it looks like it
- * could equally well be done in user mode.
- *
- * Not so, for quite unobvious reasons - register pressure.
- * In user mode vfork() cannot have a stack frame, and if
- * done by calling the "clone()" system call directly, you
- * do not have enough call-clobbered registers to hold all
- * the information you need.
+ * Idle related variables and functions
  */
-int sys_vfork(struct pt_regs *regs)
+unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
+EXPORT_SYMBOL(boot_option_idle_override);
+
+static void (*x86_idle)(void);
+
+#ifndef CONFIG_SMP
+static inline void play_dead(void)
 {
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
-		       NULL, NULL);
+	BUG();
 }
+#endif
 
-long
-sys_clone(unsigned long clone_flags, unsigned long newsp,
-	  void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
+#ifdef CONFIG_X86_64
+void enter_idle(void)
 {
-	if (!newsp)
-		newsp = regs->sp;
-	return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
+	this_cpu_write(is_idle, 1);
+	atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
 }
 
-/*
- * This gets run with %si containing the
- * function to call, and %di containing
- * the "args".
- */
-extern void kernel_thread_helper(void);
-
-/*
- * Create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+static void __exit_idle(void)
 {
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof(regs));
-
-	regs.si = (unsigned long) fn;
-	regs.di = (unsigned long) arg;
-
-#ifdef CONFIG_X86_32
-	regs.ds = __USER_DS;
-	regs.es = __USER_DS;
-	regs.fs = __KERNEL_PERCPU;
-	regs.gs = __KERNEL_STACK_CANARY;
-#else
-	regs.ss = __KERNEL_DS;
-#endif
-
-	regs.orig_ax = -1;
-	regs.ip = (unsigned long) kernel_thread_helper;
-	regs.cs = __KERNEL_CS | get_kernel_rpl();
-	regs.flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
-
-	/* Ok, create the new process.. */
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+	if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
+		return;
+	atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
 }
-EXPORT_SYMBOL(kernel_thread);
 
-/*
- * sys_execve() executes a new program.
- */
-long sys_execve(const char __user *name,
-		const char __user *const __user *argv,
-		const char __user *const __user *envp, struct pt_regs *regs)
-{
-	long error;
-	char *filename;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		return error;
-	error = do_execve(filename, argv, envp, regs);
-
-#ifdef CONFIG_X86_32
-	if (error == 0) {
-		/* Make sure we don't return using sysenter.. */
-                set_thread_flag(TIF_IRET);
-        }
-#endif
-
-	putname(filename);
-	return error;
+/* Called from interrupts to signify idle end */
+void exit_idle(void)
+{
+	/* idle loop has pid 0 */
+	if (current->pid)
+		return;
+	__exit_idle();
 }
-
-/*
- * Idle related variables and functions
- */
-unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
-EXPORT_SYMBOL(boot_option_idle_override);
-
-/*
- * Powermanagement idle function, if any..
- */
-void (*pm_idle)(void);
-#ifdef CONFIG_APM_MODULE
-EXPORT_SYMBOL(pm_idle);
 #endif
 
-#ifdef CONFIG_X86_32
-/*
- * This halt magic was a workaround for ancient floppy DMA
- * wreckage. It should be safe to remove.
- */
-static int hlt_counter;
-void disable_hlt(void)
+void arch_cpu_idle_enter(void)
 {
-	hlt_counter++;
+	local_touch_nmi();
+	enter_idle();
 }
-EXPORT_SYMBOL(disable_hlt);
 
-void enable_hlt(void)
+void arch_cpu_idle_exit(void)
 {
-	hlt_counter--;
+	__exit_idle();
 }
-EXPORT_SYMBOL(enable_hlt);
 
-static inline int hlt_use_halt(void)
+void arch_cpu_idle_dead(void)
 {
-	return (!hlt_counter && boot_cpu_data.hlt_works_ok);
+	play_dead();
 }
-#else
-static inline int hlt_use_halt(void)
+
+/*
+ * Called from the generic idle code.
+ */
+void arch_cpu_idle(void)
 {
-	return 1;
+	x86_idle();
 }
-#endif
 
 /*
- * We use this if we don't have any better
- * idle routine..
+ * We use this if we don't have any better idle routine..
  */
 void default_idle(void)
 {
-	if (hlt_use_halt()) {
-		trace_power_start(POWER_CSTATE, 1, smp_processor_id());
-		trace_cpu_idle(1, smp_processor_id());
-		current_thread_info()->status &= ~TS_POLLING;
-		/*
-		 * TS_POLLING-cleared state must be visible before we
-		 * test NEED_RESCHED:
-		 */
-		smp_mb();
-
-		if (!need_resched())
-			safe_halt();	/* enables interrupts racelessly */
-		else
-			local_irq_enable();
-		current_thread_info()->status |= TS_POLLING;
-		trace_power_end(smp_processor_id());
-		trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
-	} else {
-		local_irq_enable();
-		/* loop is done by the caller */
-		cpu_relax();
-	}
+	trace_cpu_idle_rcuidle(1, smp_processor_id());
+	safe_halt();
+	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 }
 #ifdef CONFIG_APM_MODULE
 EXPORT_SYMBOL(default_idle);
 #endif
 
-bool set_pm_idle_to_default(void)
+#ifdef CONFIG_XEN
+bool xen_set_default_idle(void)
 {
-	bool ret = !!pm_idle;
+	bool ret = !!x86_idle;
 
-	pm_idle = default_idle;
+	x86_idle = default_idle;
 
 	return ret;
 }
+#endif
 void stop_this_cpu(void *dummy)
 {
 	local_irq_disable();
@@ -420,106 +333,8 @@ void stop_this_cpu(void *dummy)
 	set_cpu_online(smp_processor_id(), false);
 	disable_local_APIC();
 
-	for (;;) {
-		if (hlt_works(smp_processor_id()))
-			halt();
-	}
-}
-
-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);
-
-/* Default MONITOR/MWAIT with no hints, used for default C1 state */
-static void mwait_idle(void)
-{
-	if (!need_resched()) {
-		trace_power_start(POWER_CSTATE, 1, smp_processor_id());
-		trace_cpu_idle(1, smp_processor_id());
-		if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
-			clflush((void *)&current_thread_info()->flags);
-
-		__monitor((void *)&current_thread_info()->flags, 0, 0);
-		smp_mb();
-		if (!need_resched())
-			__sti_mwait(0, 0);
-		else
-			local_irq_enable();
-		trace_power_end(smp_processor_id());
-		trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
-	} else
-		local_irq_enable();
-}
-
-/*
- * On SMP it's slightly faster (but much more power-consuming!)
- * to poll the ->work.need_resched flag instead of waiting for the
- * cross-CPU IPI to arrive. Use this option with caution.
- */
-static void poll_idle(void)
-{
-	trace_power_start(POWER_CSTATE, 0, smp_processor_id());
-	trace_cpu_idle(0, smp_processor_id());
-	local_irq_enable();
-	while (!need_resched())
-		cpu_relax();
-	trace_power_end(smp_processor_id());
-	trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
-}
-
-/*
- * mwait selection logic:
- *
- * It depends on the CPU. For AMD CPUs that support MWAIT this is
- * wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
- * then depend on a clock divisor and current Pstate of the core. If
- * all cores of a processor are in halt state (C1) the processor can
- * enter the C1E (C1 enhanced) state. If mwait is used this will never
- * happen.
- *
- * idle=mwait overrides this decision and forces the usage of mwait.
- */
-
-#define MWAIT_INFO			0x05
-#define MWAIT_ECX_EXTENDED_INFO		0x01
-#define MWAIT_EDX_C1			0xf0
-
-int mwait_usable(const struct cpuinfo_x86 *c)
-{
-	u32 eax, ebx, ecx, edx;
-
-	if (boot_option_idle_override == IDLE_FORCE_MWAIT)
-		return 1;
-
-	if (c->cpuid_level < MWAIT_INFO)
-		return 0;
-
-	cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx);
-	/* Check, whether EDX has extended info about MWAIT */
-	if (!(ecx & MWAIT_ECX_EXTENDED_INFO))
-		return 1;
-
-	/*
-	 * edx enumeratios MONITOR/MWAIT extensions. Check, whether
-	 * C1  supports MWAIT
-	 */
-	return (edx & MWAIT_EDX_C1);
+	for (;;)
+		halt();
 }
 
 bool amd_e400_c1e_detected;
@@ -540,9 +355,6 @@ void amd_e400_remove_cpu(int cpu)
  */
 static void amd_e400_idle(void)
 {
-	if (need_resched())
-		return;
-
 	if (!amd_e400_c1e_detected) {
 		u32 lo, hi;
 
@@ -552,7 +364,7 @@ static void amd_e400_idle(void)
 			amd_e400_c1e_detected = true;
 			if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 				mark_tsc_unstable("TSC halt in AMD C1E");
-			printk(KERN_INFO "System has AMD C1E enabled\n");
+			pr_info("System has AMD C1E enabled\n");
 		}
 	}
 
@@ -566,8 +378,7 @@ static void amd_e400_idle(void)
 			 */
 			clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
 					   &cpu);
-			printk(KERN_INFO "Switch to broadcast mode on CPU%d\n",
-			       cpu);
+			pr_info("Switch to broadcast mode on CPU%d\n", cpu);
 		}
 		clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
 
@@ -577,42 +388,34 @@ static void amd_e400_idle(void)
 		 * The switch back from broadcast mode needs to be
 		 * called with interrupts disabled.
 		 */
-		 local_irq_disable();
-		 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
-		 local_irq_enable();
+		local_irq_disable();
+		clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
+		local_irq_enable();
 	} else
 		default_idle();
 }
 
-void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
+void select_idle_routine(const struct cpuinfo_x86 *c)
 {
 #ifdef CONFIG_SMP
-	if (pm_idle == poll_idle && smp_num_siblings > 1) {
-		printk_once(KERN_WARNING "WARNING: polling idle and HT enabled,"
-			" performance may degrade.\n");
-	}
+	if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
+		pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
 #endif
-	if (pm_idle)
+	if (x86_idle || boot_option_idle_override == IDLE_POLL)
 		return;
 
-	if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
-		/*
-		 * One CPU supports mwait => All CPUs supports mwait
-		 */
-		printk(KERN_INFO "using mwait in idle threads.\n");
-		pm_idle = mwait_idle;
-	} else if (cpu_has_amd_erratum(amd_erratum_400)) {
+	if (cpu_has_bug(c, X86_BUG_AMD_APIC_C1E)) {
 		/* E400: APIC timer interrupt does not wake up CPU from C1e */
-		printk(KERN_INFO "using AMD E400 aware idle routine\n");
-		pm_idle = amd_e400_idle;
+		pr_info("using AMD E400 aware idle routine\n");
+		x86_idle = amd_e400_idle;
 	} else
-		pm_idle = default_idle;
+		x86_idle = default_idle;
 }
 
 void __init init_amd_e400_c1e_mask(void)
 {
 	/* If we're using amd_e400_idle, we need to allocate amd_e400_c1e_mask. */
-	if (pm_idle == amd_e400_idle)
+	if (x86_idle == amd_e400_idle)
 		zalloc_cpumask_var(&amd_e400_c1e_mask, GFP_KERNEL);
 }
 
@@ -622,12 +425,9 @@ static int __init idle_setup(char *str)
 		return -EINVAL;
 
 	if (!strcmp(str, "poll")) {
-		printk("using polling idle threads.\n");
-		pm_idle = poll_idle;
+		pr_info("using polling idle threads\n");
 		boot_option_idle_override = IDLE_POLL;
-	} else if (!strcmp(str, "mwait")) {
-		boot_option_idle_override = IDLE_FORCE_MWAIT;
-		WARN_ONCE(1, "\"idle=mwait\" will be removed in 2012\n");
+		cpu_idle_poll_ctrl(true);
 	} else if (!strcmp(str, "halt")) {
 		/*
 		 * When the boot option of idle=halt is added, halt is
@@ -636,7 +436,7 @@ static int __init idle_setup(char *str)
 		 * To continue to load the CPU idle driver, don't touch
 		 * the boot_option_idle_override.
 		 */
-		pm_idle = default_idle;
+		x86_idle = default_idle;
 		boot_option_idle_override = IDLE_HALT;
 	} else if (!strcmp(str, "nomwait")) {
 		/*