284 lines
7.2 KiB
C
284 lines
7.2 KiB
C
/*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <linux/fs.h>
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#include <linux/ptrace.h>
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#include <linux/reboot.h>
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#include <linux/unistd.h>
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#include <asm/sysreg.h>
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#include <asm/ocd.h>
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void (*pm_power_off)(void) = NULL;
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EXPORT_SYMBOL(pm_power_off);
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/*
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* This file handles the architecture-dependent parts of process handling..
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*/
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void cpu_idle(void)
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{
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/* endless idle loop with no priority at all */
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while (1) {
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/* TODO: Enter sleep mode */
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while (!need_resched())
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cpu_relax();
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preempt_enable_no_resched();
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schedule();
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preempt_disable();
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}
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}
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void machine_halt(void)
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{
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/*
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* Enter Stop mode. The 32 kHz oscillator will keep running so
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* the RTC will keep the time properly and the system will
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* boot quickly.
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*/
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asm volatile("sleep 3\n\t"
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"sub pc, -2");
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}
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void machine_power_off(void)
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{
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}
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void machine_restart(char *cmd)
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{
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__mtdr(DBGREG_DC, DC_DBE);
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__mtdr(DBGREG_DC, DC_RES);
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while (1) ;
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}
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/*
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* PC is actually discarded when returning from a system call -- the
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* return address must be stored in LR. This function will make sure
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* LR points to do_exit before starting the thread.
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*
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* Also, when returning from fork(), r12 is 0, so we must copy the
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* argument as well.
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*
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* r0 : The argument to the main thread function
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* r1 : The address of do_exit
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* r2 : The address of the main thread function
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*/
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asmlinkage extern void kernel_thread_helper(void);
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__asm__(" .type kernel_thread_helper, @function\n"
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"kernel_thread_helper:\n"
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" mov r12, r0\n"
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" mov lr, r2\n"
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" mov pc, r1\n"
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" .size kernel_thread_helper, . - kernel_thread_helper");
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int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
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{
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struct pt_regs regs;
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memset(®s, 0, sizeof(regs));
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regs.r0 = (unsigned long)arg;
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regs.r1 = (unsigned long)fn;
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regs.r2 = (unsigned long)do_exit;
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regs.lr = (unsigned long)kernel_thread_helper;
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regs.pc = (unsigned long)kernel_thread_helper;
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regs.sr = MODE_SUPERVISOR;
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return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
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0, ®s, 0, NULL, NULL);
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}
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EXPORT_SYMBOL(kernel_thread);
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/*
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* Free current thread data structures etc
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*/
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void exit_thread(void)
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{
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/* nothing to do */
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}
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void flush_thread(void)
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{
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/* nothing to do */
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}
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void release_thread(struct task_struct *dead_task)
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{
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/* do nothing */
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}
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static const char *cpu_modes[] = {
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"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
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"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
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};
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void show_regs(struct pt_regs *regs)
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{
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unsigned long sp = regs->sp;
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unsigned long lr = regs->lr;
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unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
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if (!user_mode(regs))
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sp = (unsigned long)regs + FRAME_SIZE_FULL;
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print_symbol("PC is at %s\n", instruction_pointer(regs));
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print_symbol("LR is at %s\n", lr);
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printk("pc : [<%08lx>] lr : [<%08lx>] %s\n"
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"sp : %08lx r12: %08lx r11: %08lx\n",
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instruction_pointer(regs),
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lr, print_tainted(), sp, regs->r12, regs->r11);
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printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
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regs->r10, regs->r9, regs->r8);
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printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
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regs->r7, regs->r6, regs->r5, regs->r4);
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printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
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regs->r3, regs->r2, regs->r1, regs->r0);
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printk("Flags: %c%c%c%c%c\n",
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regs->sr & SR_Q ? 'Q' : 'q',
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regs->sr & SR_V ? 'V' : 'v',
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regs->sr & SR_N ? 'N' : 'n',
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regs->sr & SR_Z ? 'Z' : 'z',
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regs->sr & SR_C ? 'C' : 'c');
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printk("Mode bits: %c%c%c%c%c%c%c%c%c\n",
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regs->sr & SR_H ? 'H' : 'h',
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regs->sr & SR_R ? 'R' : 'r',
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regs->sr & SR_J ? 'J' : 'j',
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regs->sr & SR_EM ? 'E' : 'e',
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regs->sr & SR_I3M ? '3' : '.',
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regs->sr & SR_I2M ? '2' : '.',
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regs->sr & SR_I1M ? '1' : '.',
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regs->sr & SR_I0M ? '0' : '.',
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regs->sr & SR_GM ? 'G' : 'g');
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printk("CPU Mode: %s\n", cpu_modes[mode]);
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show_trace(NULL, (unsigned long *)sp, regs);
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}
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EXPORT_SYMBOL(show_regs);
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/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
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int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
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{
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/* Not valid */
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return 0;
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}
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asmlinkage void ret_from_fork(void);
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int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
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unsigned long unused,
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struct task_struct *p, struct pt_regs *regs)
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{
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struct pt_regs *childregs;
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childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)p->thread_info)) - 1;
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*childregs = *regs;
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if (user_mode(regs))
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childregs->sp = usp;
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else
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childregs->sp = (unsigned long)p->thread_info + THREAD_SIZE;
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childregs->r12 = 0; /* Set return value for child */
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p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
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p->thread.cpu_context.ksp = (unsigned long)childregs;
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p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
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return 0;
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}
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/* r12-r8 are dummy parameters to force the compiler to use the stack */
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asmlinkage int sys_fork(struct pt_regs *regs)
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{
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return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
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}
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asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
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unsigned long parent_tidptr,
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unsigned long child_tidptr, struct pt_regs *regs)
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{
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if (!newsp)
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newsp = regs->sp;
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return do_fork(clone_flags, newsp, regs, 0,
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(int __user *)parent_tidptr,
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(int __user *)child_tidptr);
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}
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asmlinkage int sys_vfork(struct pt_regs *regs)
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{
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
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0, NULL, NULL);
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}
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asmlinkage int sys_execve(char __user *ufilename, char __user *__user *uargv,
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char __user *__user *uenvp, struct pt_regs *regs)
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{
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int error;
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char *filename;
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filename = getname(ufilename);
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error = PTR_ERR(filename);
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if (IS_ERR(filename))
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goto out;
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error = do_execve(filename, uargv, uenvp, regs);
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if (error == 0)
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current->ptrace &= ~PT_DTRACE;
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putname(filename);
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out:
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return error;
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}
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/*
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* This function is supposed to answer the question "who called
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* schedule()?"
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*/
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unsigned long get_wchan(struct task_struct *p)
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{
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unsigned long pc;
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unsigned long stack_page;
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if (!p || p == current || p->state == TASK_RUNNING)
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return 0;
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stack_page = (unsigned long)p->thread_info;
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BUG_ON(!stack_page);
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/*
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* The stored value of PC is either the address right after
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* the call to __switch_to() or ret_from_fork.
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*/
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pc = thread_saved_pc(p);
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if (in_sched_functions(pc)) {
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#ifdef CONFIG_FRAME_POINTER
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unsigned long fp = p->thread.cpu_context.r7;
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BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
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pc = *(unsigned long *)fp;
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#else
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/*
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* We depend on the frame size of schedule here, which
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* is actually quite ugly. It might be possible to
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* determine the frame size automatically at build
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* time by doing this:
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* - compile sched.c
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* - disassemble the resulting sched.o
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* - look for 'sub sp,??' shortly after '<schedule>:'
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*/
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unsigned long sp = p->thread.cpu_context.ksp + 16;
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BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
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pc = *(unsigned long *)sp;
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#endif
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}
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return pc;
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}
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