/* * 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); /* * This file handles the architecture-dependent parts of process handling.. */ void cpu_idle(void) { /* endless idle loop with no priority at all */ while (1) { /* TODO: Enter sleep mode */ while (!need_resched()) cpu_relax(); preempt_enable_no_resched(); schedule(); preempt_disable(); } } void machine_halt(void) { } 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; }