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-rw-r--r--arch/mn10300/kernel/process.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
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+/* 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/a.out.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(&regs, 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, &regs, 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;
+}