/*
* 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/sched.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/ptrace.h>
#include <linux/reboot.h>
#include <linux/unistd.h>
#include <asm/sysreg.h>
#include <asm/ocd.h>
void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);
extern void cpu_idle_sleep(void);
/*
* This file handles the architecture-dependent parts of process handling..
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched())
cpu_idle_sleep();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void machine_halt(void)
{
/*
* Enter Stop mode. The 32 kHz oscillator will keep running so
* the RTC will keep the time properly and the system will
* boot quickly.
*/
asm volatile("sleep 3\n\t"
"sub pc, -2");
}
void machine_power_off(void)
{
}
void machine_restart(char *cmd)
{
__mtdr(DBGREG_DC, DC_DBE);
__mtdr(DBGREG_DC, DC_RES);
while (1) ;
}
/*
* PC is actually discarded when returning from a system call -- the
* return address must be stored in LR. This function will make sure
* LR points to do_exit before starting the thread.
*
* Also, when returning from fork(), r12 is 0, so we must copy the
* argument as well.
*
* r0 : The argument to the main thread function
* r1 : The address of do_exit
* r2 : The address of the main thread function
*/
asmlinkage extern void kernel_thread_helper(void);
__asm__(" .type kernel_thread_helper, @function\n"
"kernel_thread_helper:\n"
" mov r12, r0\n"
" mov lr, r2\n"
" mov pc, r1\n"
" .size kernel_thread_helper, . - kernel_thread_helper");
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(®s, 0, sizeof(regs));
regs.r0 = (unsigned long)arg;
regs.r1 = (unsigned long)fn;
regs.r2 = (unsigned long)do_exit;
regs.lr = (unsigned long)kernel_thread_helper;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = MODE_SUPERVISOR;
return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
0, ®s, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc
*/
void exit_thread(void)
{
/* nothing to do */
}
void flush_thread(void)
{
/* nothing to do */
}
void release_thread(struct task_struct *dead_task)
{
/* do nothing */
}
static const char *cpu_modes[] = {
"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
};
void show_regs(struct pt_regs *regs)
{
unsigned long sp = regs->sp;
unsigned long lr = regs->lr;
unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
if (!user_mode(regs))
sp = (unsigned long)regs + FRAME_SIZE_FULL;
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", lr);
printk("pc : [<%08lx>] lr : [<%08lx>] %s\n"
"sp : %08lx r12: %08lx r11: %08lx\n",
instruction_pointer(regs),
lr, print_tainted(), sp, regs->r12, regs->r11);
printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
regs->r10, regs->r9, regs->r8);
printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
regs->r7, regs->r6, regs->r5, regs->r4);
printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
regs->r3, regs->r2, regs->r1, regs->r0);
printk("Flags: %c%c%c%c%c\n",
regs->sr & SR_Q ? 'Q' : 'q',
regs->sr & SR_V ? 'V' : 'v',
regs->sr & SR_N ? 'N' : 'n',
regs->sr & SR_Z ? 'Z' : 'z',
regs->sr & SR_C ? 'C' : 'c');
printk("Mode bits: %c%c%c%c%c%c%c%c%c\n",
regs->sr & SR_H ? 'H' : 'h',
regs->sr & SR_R ? 'R' : 'r',
regs->sr & SR_J ? 'J' : 'j',
regs->sr & SR_EM ? 'E' : 'e',
regs->sr & SR_I3M ? '3' : '.',
regs->sr & SR_I2M ? '2' : '.',
regs->sr & SR_I1M ? '1' : '.',
regs->sr & SR_I0M ? '0' : '.',
regs->sr & SR_GM ? 'G' : 'g');
printk("CPU Mode: %s\n", cpu_modes[mode]);
show_trace(NULL, (unsigned long *)sp, regs);
}
EXPORT_SYMBOL(show_regs);
/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
/* Not valid */
return 0;
}
asmlinkage void ret_from_fork(void);
int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs;
childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)p->thread_info)) - 1;
*childregs = *regs;
if (user_mode(regs))
childregs->sp = usp;
else
childregs->sp = (unsigned long)p->thread_info + THREAD_SIZE;
childregs->r12 = 0; /* Set return value for child */
p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
p->thread.cpu_context.ksp = (unsigned long)childregs;
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
return 0;
}
/* r12-r8 are dummy parameters to force the compiler to use the stack */
asmlinkage int sys_fork(struct pt_regs *regs)
{
return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
}
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
unsigned long parent_tidptr,
unsigned long child_tidptr, struct pt_regs *regs)
{
if (!newsp)
newsp = regs->sp;
return do_fork(clone_flags, newsp, regs, 0,
(int __user *)parent_tidptr,
(int __user *)child_tidptr);
}
asmlinkage int sys_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
0, NULL, NULL);
}
asmlinkage int sys_execve(char __user *ufilename, char __user *__user *uargv,
char __user *__user *uenvp, struct pt_regs *regs)
{
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, uargv, uenvp, regs);
if (error == 0)
current->ptrace &= ~PT_DTRACE;
putname(filename);
out:
return error;
}
/*
* This function is supposed to answer the question "who called
* schedule()?"
*/
unsigned long get_wchan(struct task_struct *p)
{
unsigned long pc;
unsigned long stack_page;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)p->thread_info;
BUG_ON(!stack_page);
/*
* The stored value of PC is either the address right after
* the call to __switch_to() or ret_from_fork.
*/
pc = thread_saved_pc(p);
if (in_sched_functions(pc)) {
#ifdef CONFIG_FRAME_POINTER
unsigned long fp = p->thread.cpu_context.r7;
BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
pc = *(unsigned long *)fp;
#else
/*
* We depend on the frame size of schedule here, which
* is actually quite ugly. It might be possible to
* determine the frame size automatically at build
* time by doing this:
* - compile sched.c
* - disassemble the resulting sched.o
* - look for 'sub sp,??' shortly after '<schedule>:'
*/
unsigned long sp = p->thread.cpu_context.ksp + 16;
BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
pc = *(unsigned long *)sp;
#endif
}
return pc;
}
