/* MN10300 Process handling code * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #include <linux/module.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/stddef.h> #include <linux/unistd.h> #include <linux/ptrace.h> #include <linux/slab.h> #include <linux/user.h> #include <linux/interrupt.h> #include <linux/delay.h> #include <linux/reboot.h> #include <linux/percpu.h> #include <linux/err.h> #include <linux/fs.h> #include <asm/uaccess.h> #include <asm/pgtable.h> #include <asm/system.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/mmu_context.h> #include <asm/fpu.h> #include <asm/reset-regs.h> #include <asm/gdb-stub.h> #include "internal.h" /* * power management idle function, if any.. */ void (*pm_idle)(void); EXPORT_SYMBOL(pm_idle); /* * return saved PC of a blocked thread. */ unsigned long thread_saved_pc(struct task_struct *tsk) { return ((unsigned long *) tsk->thread.sp)[3]; } /* * power off function, if any */ void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); /* * we use this if we don't have any better idle routine */ static void default_idle(void) { local_irq_disable(); if (!need_resched()) safe_halt(); else local_irq_enable(); } /* * the idle thread * - there's no useful work to be done, so just try to conserve power and have * a low exit latency (ie sit in a loop waiting for somebody to say that * they'd like to reschedule) */ void cpu_idle(void) { int cpu = smp_processor_id(); /* endless idle loop with no priority at all */ for (;;) { while (!need_resched()) { void (*idle)(void); smp_rmb(); idle = pm_idle; if (!idle) idle = default_idle; irq_stat[cpu].idle_timestamp = jiffies; idle(); } preempt_enable_no_resched(); schedule(); preempt_disable(); } } void release_segments(struct mm_struct *mm) { } void machine_restart(char *cmd) { #ifdef CONFIG_GDBSTUB gdbstub_exit(0); #endif #ifdef mn10300_unit_hard_reset mn10300_unit_hard_reset(); #else mn10300_proc_hard_reset(); #endif } void machine_halt(void) { #ifdef CONFIG_GDBSTUB gdbstub_exit(0); #endif } void machine_power_off(void) { #ifdef CONFIG_GDBSTUB gdbstub_exit(0); #endif } void show_regs(struct pt_regs *regs) { } /* * create a kernel thread */ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) { struct pt_regs regs; memset(®s, 0, sizeof(regs)); regs.a2 = (unsigned long) fn; regs.d2 = (unsigned long) arg; regs.pc = (unsigned long) kernel_thread_helper; local_save_flags(regs.epsw); regs.epsw |= EPSW_IE | EPSW_IM_7; /* Ok, create the new process.. */ 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) { exit_fpu(); } void flush_thread(void) { flush_fpu(); } void release_thread(struct task_struct *dead_task) { } /* * we do not have to muck with descriptors here, that is * done in switch_mm() as needed. */ void copy_segments(struct task_struct *p, struct mm_struct *new_mm) { } /* * this gets called before we allocate a new thread and copy the current task * into it so that we can store lazy state into memory */ void prepare_to_copy(struct task_struct *tsk) { unlazy_fpu(tsk); } /* * set up the kernel stack for a new thread and copy arch-specific thread * control information */ int copy_thread(unsigned long clone_flags, unsigned long c_usp, unsigned long ustk_size, struct task_struct *p, struct pt_regs *kregs) { struct pt_regs *c_uregs, *c_kregs, *uregs; unsigned long c_ksp; uregs = current->thread.uregs; c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE; /* allocate the userspace exception frame and set it up */ c_ksp -= sizeof(struct pt_regs); c_uregs = (struct pt_regs *) c_ksp; p->thread.uregs = c_uregs; *c_uregs = *uregs; c_uregs->sp = c_usp; c_uregs->epsw &= ~EPSW_FE; /* my FPU */ c_ksp -= 12; /* allocate function call ABI slack */ /* the new TLS pointer is passed in as arg #5 to sys_clone() */ if (clone_flags & CLONE_SETTLS) c_uregs->e2 = __frame->d3; /* set up the return kernel frame if called from kernel_thread() */ c_kregs = c_uregs; if (kregs != uregs) { c_ksp -= sizeof(struct pt_regs); c_kregs = (struct pt_regs *) c_ksp; *c_kregs = *kregs; c_kregs->sp = c_usp; c_kregs->next = c_uregs; #ifdef CONFIG_MN10300_CURRENT_IN_E2 c_kregs->e2 = (unsigned long) p; /* current */ #endif c_ksp -= 12; /* allocate function call ABI slack */ } /* set up things up so the scheduler can start the new task */ p->thread.__frame = c_kregs; p->thread.a3 = (unsigned long) c_kregs; p->thread.sp = c_ksp; p->thread.pc = (unsigned long) ret_from_fork; p->thread.wchan = (unsigned long) ret_from_fork; p->thread.usp = c_usp; return 0; } /* * clone a process * - tlsptr is retrieved by copy_thread() from __frame->d3 */ asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, int __user *parent_tidptr, int __user *child_tidptr, int __user *tlsptr) { return do_fork(clone_flags, newsp ?: __frame->sp, __frame, 0, parent_tidptr, child_tidptr); } asmlinkage long sys_fork(void) { return do_fork(SIGCHLD, __frame->sp, __frame, 0, NULL, NULL); } asmlinkage long sys_vfork(void) { return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, __frame->sp, __frame, 0, NULL, NULL); } asmlinkage long sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp) { char *filename; int error; lock_kernel(); filename = getname(name); error = PTR_ERR(filename); if (!IS_ERR(filename)) { error = do_execve(filename, argv, envp, __frame); putname(filename); } unlock_kernel(); return error; } unsigned long get_wchan(struct task_struct *p) { return p->thread.wchan; }