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/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/bitops.h>
#include <asm/system.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h> /* for USER_DS macros */
#include <asm/cacheflush.h>
void show_regs(struct pt_regs *regs)
{
printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode);
printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
regs->r1, regs->r2, regs->r3, regs->r4);
printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
regs->r5, regs->r6, regs->r7, regs->r8);
printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
regs->r9, regs->r10, regs->r11, regs->r12);
printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
regs->r13, regs->r14, regs->r15, regs->r16);
printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
regs->r17, regs->r18, regs->r19, regs->r20);
printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
regs->r21, regs->r22, regs->r23, regs->r24);
printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
regs->r25, regs->r26, regs->r27, regs->r28);
printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
regs->r29, regs->r30, regs->r31, regs->pc);
printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
regs->msr, regs->ear, regs->esr, regs->fsr);
}
void (*pm_idle)(void);
void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);
static int hlt_counter = 1;
void disable_hlt(void)
{
hlt_counter++;
}
EXPORT_SYMBOL(disable_hlt);
void enable_hlt(void)
{
hlt_counter--;
}
EXPORT_SYMBOL(enable_hlt);
static int __init nohlt_setup(char *__unused)
{
hlt_counter = 1;
return 1;
}
__setup("nohlt", nohlt_setup);
static int __init hlt_setup(char *__unused)
{
hlt_counter = 0;
return 1;
}
__setup("hlt", hlt_setup);
void default_idle(void)
{
if (likely(hlt_counter)) {
local_irq_disable();
stop_critical_timings();
cpu_relax();
start_critical_timings();
local_irq_enable();
} else {
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb__after_clear_bit();
local_irq_disable();
while (!need_resched())
cpu_sleep();
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
}
}
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
void (*idle)(void) = pm_idle;
if (!idle)
idle = default_idle;
tick_nohz_stop_sched_tick(1);
while (!need_resched())
idle();
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
}
void flush_thread(void)
{
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs = task_pt_regs(p);
struct thread_info *ti = task_thread_info(p);
*childregs = *regs;
if (user_mode(regs))
childregs->r1 = usp;
else
childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
#ifndef CONFIG_MMU
memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
ti->cpu_context.r1 = (unsigned long)childregs;
ti->cpu_context.msr = (unsigned long)childregs->msr;
#else
/* if creating a kernel thread then update the current reg (we don't
* want to use the parent's value when restoring by POP_STATE) */
if (kernel_mode(regs))
/* save new current on stack to use POP_STATE */
childregs->CURRENT_TASK = (unsigned long)p;
/* if returning to user then use the parent's value of this register */
/* if we're creating a new kernel thread then just zeroing all
* the registers. That's OK for a brand new thread.*/
/* Pls. note that some of them will be restored in POP_STATE */
if (kernel_mode(regs))
memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
/* if this thread is created for fork/vfork/clone, then we want to
* restore all the parent's context */
/* in addition to the registers which will be restored by POP_STATE */
else {
ti->cpu_context = *(struct cpu_context *)regs;
childregs->msr |= MSR_UMS;
}
/* FIXME STATE_SAVE_PT_OFFSET; */
ti->cpu_context.r1 = (unsigned long)childregs - STATE_SAVE_ARG_SPACE;
/* we should consider the fact that childregs is a copy of the parent
* regs which were saved immediately after entering the kernel state
* before enabling VM. This MSR will be restored in switch_to and
* RETURN() and we want to have the right machine state there
* specifically this state must have INTs disabled before and enabled
* after performing rtbd
* compose the right MSR for RETURN(). It will work for switch_to also
* excepting for VM and UMS
* don't touch UMS , CARRY and cache bits
* right now MSR is a copy of parent one */
childregs->msr |= MSR_BIP;
childregs->msr &= ~MSR_EIP;
childregs->msr |= MSR_IE;
childregs->msr &= ~MSR_VM;
childregs->msr |= MSR_VMS;
childregs->msr |= MSR_EE; /* exceptions will be enabled*/
ti->cpu_context.msr = (childregs->msr|MSR_VM);
ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
#endif
ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
if (clone_flags & CLONE_SETTLS)
;
return 0;
}
#ifndef CONFIG_MMU
/*
* Return saved PC of a blocked thread.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct cpu_context *ctx =
&(((struct thread_info *)(tsk->stack))->cpu_context);
/* Check whether the thread is blocked in resume() */
if (in_sched_functions(ctx->r15))
return (unsigned long)ctx->r15;
else
return ctx->r14;
}
#endif
static void kernel_thread_helper(int (*fn)(void *), void *arg)
{
fn(arg);
do_exit(-1);
}
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(®s, 0, sizeof(regs));
/* store them in non-volatile registers */
regs.r5 = (unsigned long)fn;
regs.r6 = (unsigned long)arg;
local_save_flags(regs.msr);
regs.pc = (unsigned long)kernel_thread_helper;
regs.pt_mode = 1;
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
®s, 0, NULL, NULL);
}
EXPORT_SYMBOL_GPL(kernel_thread);
unsigned long get_wchan(struct task_struct *p)
{
/* TBD (used by procfs) */
return 0;
}
/* Set up a thread for executing a new program */
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
{
set_fs(USER_DS);
regs->pc = pc;
regs->r1 = usp;
regs->pt_mode = 0;
#ifdef CONFIG_MMU
regs->msr |= MSR_UMS;
#endif
}
#ifdef CONFIG_MMU
#include <linux/elfcore.h>
/*
* Set up a thread for executing a new program
*/
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
return 0; /* MicroBlaze has no separate FPU registers */
}
#endif /* CONFIG_MMU */
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