path: root/arch/sparc64/kernel/process.c

/*  arch/sparc64/kernel/process.c
 *
 *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
 *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
 *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#include <stdarg.h>

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/compat.h>
#include <linux/tick.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/sysrq.h>

#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/pstate.h>
#include <asm/elf.h>
#include <asm/fpumacro.h>
#include <asm/head.h>
#include <asm/cpudata.h>
#include <asm/mmu_context.h>
#include <asm/unistd.h>
#include <asm/hypervisor.h>
#include <asm/sstate.h>
#include <asm/reboot.h>
#include <asm/syscalls.h>
#include <asm/irq_regs.h>
#include <asm/smp.h>

static void sparc64_yield(int cpu)
{
	if (tlb_type != hypervisor)
		return;

	clear_thread_flag(TIF_POLLING_NRFLAG);
	smp_mb__after_clear_bit();

	while (!need_resched() && !cpu_is_offline(cpu)) {
		unsigned long pstate;

		/* Disable interrupts. */
		__asm__ __volatile__(
			"rdpr %%pstate, %0\n\t"
			"andn %0, %1, %0\n\t"
			"wrpr %0, %%g0, %%pstate"
			: "=&r" (pstate)
			: "i" (PSTATE_IE));

		if (!need_resched() && !cpu_is_offline(cpu))
			sun4v_cpu_yield();

		/* Re-enable interrupts. */
		__asm__ __volatile__(
			"rdpr %%pstate, %0\n\t"
			"or %0, %1, %0\n\t"
			"wrpr %0, %%g0, %%pstate"
			: "=&r" (pstate)
			: "i" (PSTATE_IE));
	}

	set_thread_flag(TIF_POLLING_NRFLAG);
}

/* The idle loop on sparc64. */
void cpu_idle(void)
{
	int cpu = smp_processor_id();

	set_thread_flag(TIF_POLLING_NRFLAG);

	while(1) {
		tick_nohz_stop_sched_tick(1);

		while (!need_resched() && !cpu_is_offline(cpu))
			sparc64_yield(cpu);

		tick_nohz_restart_sched_tick();

		preempt_enable_no_resched();

#ifdef CONFIG_HOTPLUG_CPU
		if (cpu_is_offline(cpu))
			cpu_play_dead();
#endif

		schedule();
		preempt_disable();
	}
}

void machine_halt(void)
{
	sstate_halt();
	prom_halt();
	panic("Halt failed!");
}

void machine_alt_power_off(void)
{
	sstate_poweroff();
	prom_halt_power_off();
	panic("Power-off failed!");
}

void machine_restart(char * cmd)
{
	char *p;
	
	sstate_reboot();
	p = strchr (reboot_command, '\n');
	if (p) *p = 0;
	if (cmd)
		prom_reboot(cmd);
	if (*reboot_command)
		prom_reboot(reboot_command);
	prom_reboot("");
	panic("Reboot failed!");
}

#ifdef CONFIG_COMPAT
static void show_regwindow32(struct pt_regs *regs)
{
	struct reg_window32 __user *rw;
	struct reg_window32 r_w;
	mm_segment_t old_fs;
	
	__asm__ __volatile__ ("flushw");
	rw = compat_ptr((unsigned)regs->u_regs[14]);
	old_fs = get_fs();
	set_fs (USER_DS);
	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
		set_fs (old_fs);
		return;
	}

	set_fs (old_fs);			
	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
}
#else
#define show_regwindow32(regs)	do { } while (0)
#endif

static void show_regwindow(struct pt_regs *regs)
{
	struct reg_window __user *rw;
	struct reg_window *rwk;
	struct reg_window r_w;
	mm_segment_t old_fs;

	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
		__asm__ __volatile__ ("flushw");
		rw = (struct reg_window __user *)
			(regs->u_regs[14] + STACK_BIAS);
		rwk = (struct reg_window *)
			(regs->u_regs[14] + STACK_BIAS);
		if (!(regs->tstate & TSTATE_PRIV)) {
			old_fs = get_fs();
			set_fs (USER_DS);
			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
				set_fs (old_fs);
				return;
			}
			rwk = &r_w;
			set_fs (old_fs);			
		}
	} else {
		show_regwindow32(