| /* 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); |
| } |
| |
| /* |
| * 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(int nr, 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); |
| if (error == 0) |
| current->ptrace &= ~PT_DTRACE; |
| |
| putname(filename); |
| } |
| |
| unlock_kernel(); |
| return error; |
| } |
| |
| unsigned long get_wchan(struct task_struct *p) |
| { |
| return p->thread.wchan; |
| } |