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