Initial import

1 files changed, 546 insertions, 0 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
new file mode 100644
index 000000000..6e338e3b1
--- /dev/null
+++ b/arch/x86/kernel/process.c
@@ -0,0 +1,546 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/prctl.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/tick.h>
+#include <linux/random.h>
+#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/apic.h>
+#include <asm/syscalls.h>
+#include <asm/idle.h>
+#include <asm/uaccess.h>
+#include <asm/mwait.h>
+#include <asm/i387.h>
+#include <asm/fpu-internal.h>
+#include <asm/debugreg.h>
+#include <asm/nmi.h>
+#include <asm/tlbflush.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, cpu_tss) = {
+	.x86_tss = {
+		.sp0 = TOP_OF_INIT_STACK,
+#ifdef CONFIG_X86_32
+		.ss0 = __KERNEL_DS,
+		.ss1 = __KERNEL_CS,
+		.io_bitmap_base	= INVALID_IO_BITMAP_OFFSET,
+#endif
+	 },
+#ifdef CONFIG_X86_32
+	 /*
+	  * Note that the .io_bitmap member must be extra-big. This is because
+	  * the CPU will access an additional byte beyond the end of the IO
+	  * permission bitmap. The extra byte must be all 1 bits, and must
+	  * be within the limit.
+	  */
+	.io_bitmap		= { [0 ... IO_BITMAP_LONGS] = ~0 },
+#endif
+};
+EXPORT_PER_CPU_SYMBOL(cpu_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)
+{
+	*dst = *src;
+
+	dst->thread.fpu_counter = 0;
+	dst->thread.fpu.has_fpu = 0;
+	dst->thread.fpu.state = NULL;
+	task_disable_lazy_fpu_restore(dst);
+	if (tsk_used_math(src)) {
+		int err = fpu_alloc(&dst->thread.fpu);
+		if (err)
+			return err;
+		fpu_copy(dst, src);
+	}
+	return 0;
+}
+
+void free_thread_xstate(struct task_struct *tsk)
+{
+	fpu_free(&tsk->thread.fpu);
+}
+
+void arch_release_task_struct(struct task_struct *tsk)
+{
+	free_thread_xstate(tsk);
+}
+
+void arch_task_cache_init(void)
+{
+        task_xstate_cachep =
+        	kmem_cache_create("task_xstate", xstate_size,
+				  __alignof__(union thread_xstate),
+				  SLAB_PANIC | SLAB_NOTRACK, NULL);
+	setup_xstate_comp();
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+	struct task_struct *me = current;
+	struct thread_struct *t = &me->thread;
+	unsigned long *bp = t->io_bitmap_ptr;
+
+	if (bp) {
+		struct tss_struct *tss = &per_cpu(cpu_tss, get_cpu());
+
+		t->io_bitmap_ptr = NULL;
+		clear_thread_flag(TIF_IO_BITMAP);
+		/*
+		 * Careful, clear this in the TSS too:
+		 */
+		memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
+		t->io_bitmap_max = 0;
+		put_cpu();
+		kfree(bp);
+	}
+
+	drop_fpu(me);
+}
+
+void flush_thread(void)
+{
+	struct task_struct *tsk = current;
+
+	flush_ptrace_hw_breakpoint(tsk);
+	memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
+
+	if (!use_eager_fpu()) {
+		/* FPU state will be reallocated lazily at the first use. */
+		drop_fpu(tsk);
+		free_thread_xstate(tsk);
+	} else {
+		if (!tsk_used_math(tsk)) {
+			/* kthread execs. TODO: cleanup this horror. */
+			if (WARN_ON(init_fpu(tsk)))
+				force_sig(SIGKILL, tsk);
+			user_fpu_begin();
+		}
+		restore_init_xstate();
+	}
+}
+
+static void hard_disable_TSC(void)
+{
+	cr4_set_bits(X86_CR4_TSD);
+}
+
+void disable_TSC(void)
+{
+	preempt_disable();
+	if (!test_and_set_thread_flag(TIF_NOTSC))
+		/*
+		 * Must flip the CPU state synchronously with
+		 * TIF_NOTSC in the current running context.
+		 */
+		hard_disable_TSC();
+	preempt_enable();
+}
+
+static void hard_enable_TSC(void)
+{
+	cr4_clear_bits(X86_CR4_TSD);
+}
+
+static void enable_TSC(void)
+{
+	preempt_disable();
+	if (test_and_clear_thread_flag(TIF_NOTSC))
+		/*
+		 * Must flip the CPU state synchronously with
+		 * TIF_NOTSC in the current running context.
+		 */
+		hard_enable_TSC();
+	preempt_enable();
+}
+
+int get_tsc_mode(unsigned long adr)
+{
+	unsigned int val;
+
+	if (test_thread_flag(TIF_NOTSC))
+		val = PR_TSC_SIGSEGV;
+	else
+		val = PR_TSC_ENABLE;
+
+	return put_user(val, (unsigned int __user *)adr);
+}
+
+int set_tsc_mode(unsigned int val)
+{
+	if (val == PR_TSC_SIGSEGV)
+		disable_TSC();
+	else if (val == PR_TSC_ENABLE)
+		enable_TSC();
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
+		      struct tss_struct *tss)
+{
+	struct thread_struct *prev, *next;
+
+	prev = &prev_p->thread;
+	next = &next_p->thread;
+
+	if (test_tsk_thread_flag(prev_p, TIF_BLOCKSTEP) ^
+	    test_tsk_thread_flag(next_p, TIF_BLOCKSTEP)) {
+		unsigned long debugctl = get_debugctlmsr();
+
+		debugctl &= ~DEBUGCTLMSR_BTF;
+		if (test_tsk_thread_flag(next_p, TIF_BLOCKSTEP))
+			debugctl |= DEBUGCTLMSR_BTF;
+
+		update_debugctlmsr(debugctl);
+	}
+
+	if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
+	    test_tsk_thread_flag(next_p, TIF_NOTSC)) {
+		/* prev and next are different */
+		if (test_tsk_thread_flag(next_p, TIF_NOTSC))
+			hard_disable_TSC();
+		else
+			hard_enable_TSC();
+	}
+
+	if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
+		/*
+		 * Copy the relevant range of the IO bitmap.
+		 * Normally this is 128 bytes or less:
+		 */
+		memcpy(tss->io_bitmap, next->io_bitmap_ptr,
+		       max(prev->io_bitmap_max, next->io_bitmap_max));
+	} else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
+		/*
+		 * Clear any possible leftover bits:
+		 */
+		memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
+	}
+	propagate_user_return_notify(prev_p, next_p);
+}
+
+/*
+ * Idle related variables and functions
+ */
+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)
+{
+	BUG();
+}
+#endif
+
+#ifdef CONFIG_X86_64
+void enter_idle(void)
+{
+	this_cpu_write(is_idle, 1);
+	atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
+}
+
+static void __exit_idle(void)
+{
+	if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
+		return;
+	atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
+}
+
+/* Called from interrupts to signify idle end */
+void exit_idle(void)
+{
+	/* idle loop has pid 0 */
+	if (current->pid)
+		return;
+	__exit_idle();
+}
+#endif
+
+void arch_cpu_idle_enter(void)
+{
+	local_touch_nmi();
+	enter_idle();
+}
+
+void arch_cpu_idle_exit(void)
+{
+	__exit_idle();
+}
+
+void arch_cpu_idle_dead(void)
+{
+	play_dead();
+}
+
+/*
+ * Called from the generic idle code.
+ */
+void arch_cpu_idle(void)
+{
+	x86_idle();
+}
+
+/*
+ * We use this if we don't have any better idle routine..
+ */
+void default_idle(void)
+{
+	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
+
+#ifdef CONFIG_XEN
+bool xen_set_default_idle(void)
+{
+	bool ret = !!x86_idle;
+
+	x86_idle = default_idle;
+
+	return ret;
+}
+#endif
+void stop_this_cpu(void *dummy)
+{
+	local_irq_disable();
+	/*
+	 * Remove this CPU:
+	 */
+	set_cpu_online(smp_processor_id(), false);
+	disable_local_APIC();
+
+	for (;;)
+		halt();
+}
+
+bool amd_e400_c1e_detected;
+EXPORT_SYMBOL(amd_e400_c1e_detected);
+
+static cpumask_var_t amd_e400_c1e_mask;
+
+void amd_e400_remove_cpu(int cpu)
+{
+	if (amd_e400_c1e_mask != NULL)
+		cpumask_clear_cpu(cpu, amd_e400_c1e_mask);
+}
+
+/*
+ * AMD Erratum 400 aware idle routine. We check for C1E active in the interrupt
+ * pending message MSR. If we detect C1E, then we handle it the same
+ * way as C3 power states (local apic timer and TSC stop)
+ */
+static void amd_e400_idle(void)
+{
+	if (!amd_e400_c1e_detected) {
+		u32 lo, hi;
+
+		rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
+
+		if (lo & K8_INTP_C1E_ACTIVE_MASK) {
+			amd_e400_c1e_detected = true;
+			if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+				mark_tsc_unstable("TSC halt in AMD C1E");
+			pr_info("System has AMD C1E enabled\n");
+		}
+	}
+
+	if (amd_e400_c1e_detected) {
+		int cpu = smp_processor_id();
+
+		if (!cpumask_test_cpu(cpu, amd_e400_c1e_mask)) {
+			cpumask_set_cpu(cpu, amd_e400_c1e_mask);
+			/* Force broadcast so ACPI can not interfere. */
+			tick_broadcast_force();
+			pr_info("Switch to broadcast mode on CPU%d\n", cpu);
+		}
+		tick_broadcast_enter();
+
+		default_idle();
+
+		/*
+		 * The switch back from broadcast mode needs to be
+		 * called with interrupts disabled.
+		 */
+		local_irq_disable();
+		tick_broadcast_exit();
+		local_irq_enable();
+	} else
+		default_idle();
+}
+
+/*
+ * Intel Core2 and older machines prefer MWAIT over HALT for C1.
+ * We can't rely on cpuidle installing MWAIT, because it will not load
+ * on systems that support only C1 -- so the boot default must be MWAIT.
+ *
+ * Some AMD machines are the opposite, they depend on using HALT.
+ *
+ * So for default C1, which is used during boot until cpuidle loads,
+ * use MWAIT-C1 on Intel HW that has it, else use HALT.
+ */
+static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c)
+{
+	if (c->x86_vendor != X86_VENDOR_INTEL)
+		return 0;
+
+	if (!cpu_has(c, X86_FEATURE_MWAIT))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * MONITOR/MWAIT with no hints, used for default default C1 state.
+ * This invokes MWAIT with interrutps enabled and no flags,
+ * which is backwards compatible with the original MWAIT implementation.
+ */
+
+static void mwait_idle(void)
+{
+	if (!current_set_polling_and_test()) {
+		if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) {
+			smp_mb(); /* quirk */
+			clflush((void *)&current_thread_info()->flags);
+			smp_mb(); /* quirk */
+		}
+
+		__monitor((void *)&current_thread_info()->flags, 0, 0);
+		if (!need_resched())
+			__sti_mwait(0, 0);
+		else
+			local_irq_enable();
+	} else {
+		local_irq_enable();
+	}
+	__current_clr_polling();
+}
+
+void select_idle_routine(const struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+	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 (x86_idle || boot_option_idle_override == IDLE_POLL)
+		return;
+
+	if (cpu_has_bug(c, X86_BUG_AMD_APIC_C1E)) {
+		/* E400: APIC timer interrupt does not wake up CPU from C1e */
+		pr_info("using AMD E400 aware idle routine\n");
+		x86_idle = amd_e400_idle;
+	} else if (prefer_mwait_c1_over_halt(c)) {
+		pr_info("using mwait in idle threads\n");
+		x86_idle = mwait_idle;
+	} else
+		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 (x86_idle == amd_e400_idle)
+		zalloc_cpumask_var(&amd_e400_c1e_mask, GFP_KERNEL);
+}
+
+static int __init idle_setup(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	if (!strcmp(str, "poll")) {
+		pr_info("using polling idle threads\n");
+		boot_option_idle_override = IDLE_POLL;
+		cpu_idle_poll_ctrl(true);
+	} else if (!strcmp(str, "halt")) {
+		/*
+		 * When the boot option of idle=halt is added, halt is
+		 * forced to be used for CPU idle. In such case CPU C2/C3
+		 * won't be used again.
+		 * To continue to load the CPU idle driver, don't touch
+		 * the boot_option_idle_override.
+		 */
+		x86_idle = default_idle;
+		boot_option_idle_override = IDLE_HALT;
+	} else if (!strcmp(str, "nomwait")) {
+		/*
+		 * If the boot option of "idle=nomwait" is added,
+		 * it means that mwait will be disabled for CPU C2/C3
+		 * states. In such case it won't touch the variable
+		 * of boot_option_idle_override.
+		 */
+		boot_option_idle_override = IDLE_NOMWAIT;
+	} else
+		return -1;
+
+	return 0;
+}
+early_param("idle", idle_setup);
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() % 8192;
+	return sp & ~0xf;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long range_end = mm->brk + 0x02000000;
+	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+}
+