OMAP: Add new function to check wether there is irq pending
[linux-ginger.git] / arch / mn10300 / kernel / process.c
blob234cf344cdceb1e39f550947ddae8d2331435d63
1 /* MN10300 Process handling code
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/mm.h>
16 #include <linux/smp.h>
17 #include <linux/smp_lock.h>
18 #include <linux/stddef.h>
19 #include <linux/unistd.h>
20 #include <linux/ptrace.h>
21 #include <linux/slab.h>
22 #include <linux/user.h>
23 #include <linux/interrupt.h>
24 #include <linux/delay.h>
25 #include <linux/reboot.h>
26 #include <linux/percpu.h>
27 #include <linux/err.h>
28 #include <linux/fs.h>
29 #include <asm/uaccess.h>
30 #include <asm/pgtable.h>
31 #include <asm/system.h>
32 #include <asm/io.h>
33 #include <asm/processor.h>
34 #include <asm/mmu_context.h>
35 #include <asm/fpu.h>
36 #include <asm/reset-regs.h>
37 #include <asm/gdb-stub.h>
38 #include "internal.h"
41 * power management idle function, if any..
43 void (*pm_idle)(void);
44 EXPORT_SYMBOL(pm_idle);
47 * return saved PC of a blocked thread.
49 unsigned long thread_saved_pc(struct task_struct *tsk)
51 return ((unsigned long *) tsk->thread.sp)[3];
55 * power off function, if any
57 void (*pm_power_off)(void);
58 EXPORT_SYMBOL(pm_power_off);
61 * we use this if we don't have any better idle routine
63 static void default_idle(void)
65 local_irq_disable();
66 if (!need_resched())
67 safe_halt();
68 else
69 local_irq_enable();
73 * the idle thread
74 * - there's no useful work to be done, so just try to conserve power and have
75 * a low exit latency (ie sit in a loop waiting for somebody to say that
76 * they'd like to reschedule)
78 void cpu_idle(void)
80 int cpu = smp_processor_id();
82 /* endless idle loop with no priority at all */
83 for (;;) {
84 while (!need_resched()) {
85 void (*idle)(void);
87 smp_rmb();
88 idle = pm_idle;
89 if (!idle)
90 idle = default_idle;
92 irq_stat[cpu].idle_timestamp = jiffies;
93 idle();
96 preempt_enable_no_resched();
97 schedule();
98 preempt_disable();
102 void release_segments(struct mm_struct *mm)
106 void machine_restart(char *cmd)
108 #ifdef CONFIG_GDBSTUB
109 gdbstub_exit(0);
110 #endif
112 #ifdef mn10300_unit_hard_reset
113 mn10300_unit_hard_reset();
114 #else
115 mn10300_proc_hard_reset();
116 #endif
119 void machine_halt(void)
121 #ifdef CONFIG_GDBSTUB
122 gdbstub_exit(0);
123 #endif
126 void machine_power_off(void)
128 #ifdef CONFIG_GDBSTUB
129 gdbstub_exit(0);
130 #endif
133 void show_regs(struct pt_regs *regs)
138 * create a kernel thread
140 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
142 struct pt_regs regs;
144 memset(&regs, 0, sizeof(regs));
146 regs.a2 = (unsigned long) fn;
147 regs.d2 = (unsigned long) arg;
148 regs.pc = (unsigned long) kernel_thread_helper;
149 local_save_flags(regs.epsw);
150 regs.epsw |= EPSW_IE | EPSW_IM_7;
152 /* Ok, create the new process.. */
153 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0,
154 NULL, NULL);
156 EXPORT_SYMBOL(kernel_thread);
159 * free current thread data structures etc..
161 void exit_thread(void)
163 exit_fpu();
166 void flush_thread(void)
168 flush_fpu();
171 void release_thread(struct task_struct *dead_task)
176 * we do not have to muck with descriptors here, that is
177 * done in switch_mm() as needed.
179 void copy_segments(struct task_struct *p, struct mm_struct *new_mm)
184 * this gets called before we allocate a new thread and copy the current task
185 * into it so that we can store lazy state into memory
187 void prepare_to_copy(struct task_struct *tsk)
189 unlazy_fpu(tsk);
193 * set up the kernel stack for a new thread and copy arch-specific thread
194 * control information
196 int copy_thread(unsigned long clone_flags,
197 unsigned long c_usp, unsigned long ustk_size,
198 struct task_struct *p, struct pt_regs *kregs)
200 struct pt_regs *c_uregs, *c_kregs, *uregs;
201 unsigned long c_ksp;
203 uregs = current->thread.uregs;
205 c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE;
207 /* allocate the userspace exception frame and set it up */
208 c_ksp -= sizeof(struct pt_regs);
209 c_uregs = (struct pt_regs *) c_ksp;
211 p->thread.uregs = c_uregs;
212 *c_uregs = *uregs;
213 c_uregs->sp = c_usp;
214 c_uregs->epsw &= ~EPSW_FE; /* my FPU */
216 c_ksp -= 12; /* allocate function call ABI slack */
218 /* the new TLS pointer is passed in as arg #5 to sys_clone() */
219 if (clone_flags & CLONE_SETTLS)
220 c_uregs->e2 = __frame->d3;
222 /* set up the return kernel frame if called from kernel_thread() */
223 c_kregs = c_uregs;
224 if (kregs != uregs) {
225 c_ksp -= sizeof(struct pt_regs);
226 c_kregs = (struct pt_regs *) c_ksp;
227 *c_kregs = *kregs;
228 c_kregs->sp = c_usp;
229 c_kregs->next = c_uregs;
230 #ifdef CONFIG_MN10300_CURRENT_IN_E2
231 c_kregs->e2 = (unsigned long) p; /* current */
232 #endif
234 c_ksp -= 12; /* allocate function call ABI slack */
237 /* set up things up so the scheduler can start the new task */
238 p->thread.__frame = c_kregs;
239 p->thread.a3 = (unsigned long) c_kregs;
240 p->thread.sp = c_ksp;
241 p->thread.pc = (unsigned long) ret_from_fork;
242 p->thread.wchan = (unsigned long) ret_from_fork;
243 p->thread.usp = c_usp;
245 return 0;
249 * clone a process
250 * - tlsptr is retrieved by copy_thread() from __frame->d3
252 asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
253 int __user *parent_tidptr, int __user *child_tidptr,
254 int __user *tlsptr)
256 return do_fork(clone_flags, newsp ?: __frame->sp, __frame, 0,
257 parent_tidptr, child_tidptr);
260 asmlinkage long sys_fork(void)
262 return do_fork(SIGCHLD, __frame->sp, __frame, 0, NULL, NULL);
265 asmlinkage long sys_vfork(void)
267 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, __frame->sp, __frame,
268 0, NULL, NULL);
271 asmlinkage long sys_execve(char __user *name,
272 char __user * __user *argv,
273 char __user * __user *envp)
275 char *filename;
276 int error;
278 lock_kernel();
280 filename = getname(name);
281 error = PTR_ERR(filename);
282 if (!IS_ERR(filename)) {
283 error = do_execve(filename, argv, envp, __frame);
284 if (error == 0)
285 current->ptrace &= ~PT_DTRACE;
287 putname(filename);
290 unlock_kernel();
291 return error;
294 unsigned long get_wchan(struct task_struct *p)
296 return p->thread.wchan;