ia64/linux-2.6.18-xen.hg

view arch/cris/arch-v10/kernel/process.c @ 647:a5bb490065f6

Fix the build after public header sync.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Wed Aug 13 14:01:49 2008 +0100 (2008-08-13)
parents 831230e53067
children
line source
1 /* $Id: process.c,v 1.12 2004/12/27 11:18:32 starvik Exp $
2 *
3 * linux/arch/cris/kernel/process.c
4 *
5 * Copyright (C) 1995 Linus Torvalds
6 * Copyright (C) 2000-2002 Axis Communications AB
7 *
8 * Authors: Bjorn Wesen (bjornw@axis.com)
9 * Mikael Starvik (starvik@axis.com)
10 *
11 * This file handles the architecture-dependent parts of process handling..
12 */
14 #include <linux/sched.h>
15 #include <linux/err.h>
16 #include <linux/fs.h>
17 #include <linux/slab.h>
18 #include <asm/arch/svinto.h>
19 #include <linux/init.h>
21 #ifdef CONFIG_ETRAX_GPIO
22 void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */
23 #endif
25 /*
26 * We use this if we don't have any better
27 * idle routine..
28 */
29 void default_idle(void)
30 {
31 #ifdef CONFIG_ETRAX_GPIO
32 etrax_gpio_wake_up_check();
33 #endif
34 }
36 /*
37 * Free current thread data structures etc..
38 */
40 void exit_thread(void)
41 {
42 /* Nothing needs to be done. */
43 }
45 /* if the watchdog is enabled, we can simply disable interrupts and go
46 * into an eternal loop, and the watchdog will reset the CPU after 0.1s
47 * if on the other hand the watchdog wasn't enabled, we just enable it and wait
48 */
50 void hard_reset_now (void)
51 {
52 /*
53 * Don't declare this variable elsewhere. We don't want any other
54 * code to know about it than the watchdog handler in entry.S and
55 * this code, implementing hard reset through the watchdog.
56 */
57 #if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
58 extern int cause_of_death;
59 #endif
61 printk("*** HARD RESET ***\n");
62 local_irq_disable();
64 #if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
65 cause_of_death = 0xbedead;
66 #else
67 /* Since we dont plan to keep on reseting the watchdog,
68 the key can be arbitrary hence three */
69 *R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, 3) |
70 IO_STATE(R_WATCHDOG, enable, start);
71 #endif
73 while(1) /* waiting for RETRIBUTION! */ ;
74 }
76 /*
77 * Return saved PC of a blocked thread.
78 */
79 unsigned long thread_saved_pc(struct task_struct *t)
80 {
81 return task_pt_regs(t)->irp;
82 }
84 static void kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
85 {
86 fn(arg);
87 do_exit(-1); /* Should never be called, return bad exit value */
88 }
90 /*
91 * Create a kernel thread
92 */
93 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
94 {
95 struct pt_regs regs;
97 memset(&regs, 0, sizeof(regs));
99 /* Don't use r10 since that is set to 0 in copy_thread */
100 regs.r11 = (unsigned long)fn;
101 regs.r12 = (unsigned long)arg;
102 regs.irp = (unsigned long)kernel_thread_helper;
103 regs.dccr = 1 << I_DCCR_BITNR;
105 /* Ok, create the new process.. */
106 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
107 }
109 /* setup the child's kernel stack with a pt_regs and switch_stack on it.
110 * it will be un-nested during _resume and _ret_from_sys_call when the
111 * new thread is scheduled.
112 *
113 * also setup the thread switching structure which is used to keep
114 * thread-specific data during _resumes.
115 *
116 */
117 asmlinkage void ret_from_fork(void);
119 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
120 unsigned long unused,
121 struct task_struct *p, struct pt_regs *regs)
122 {
123 struct pt_regs * childregs;
124 struct switch_stack *swstack;
126 /* put the pt_regs structure at the end of the new kernel stack page and fix it up
127 * remember that the task_struct doubles as the kernel stack for the task
128 */
130 childregs = task_pt_regs(p);
132 *childregs = *regs; /* struct copy of pt_regs */
134 p->set_child_tid = p->clear_child_tid = NULL;
136 childregs->r10 = 0; /* child returns 0 after a fork/clone */
138 /* put the switch stack right below the pt_regs */
140 swstack = ((struct switch_stack *)childregs) - 1;
142 swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */
144 /* we want to return into ret_from_sys_call after the _resume */
146 swstack->return_ip = (unsigned long) ret_from_fork; /* Will call ret_from_sys_call */
148 /* fix the user-mode stackpointer */
150 p->thread.usp = usp;
152 /* and the kernel-mode one */
154 p->thread.ksp = (unsigned long) swstack;
156 #ifdef DEBUG
157 printk("copy_thread: new regs at 0x%p, as shown below:\n", childregs);
158 show_registers(childregs);
159 #endif
161 return 0;
162 }
164 /*
165 * Be aware of the "magic" 7th argument in the four system-calls below.
166 * They need the latest stackframe, which is put as the 7th argument by
167 * entry.S. The previous arguments are dummies or actually used, but need
168 * to be defined to reach the 7th argument.
169 *
170 * N.B.: Another method to get the stackframe is to use current_regs(). But
171 * it returns the latest stack-frame stacked when going from _user mode_ and
172 * some of these (at least sys_clone) are called from kernel-mode sometimes
173 * (for example during kernel_thread, above) and thus cannot use it. Thus,
174 * to be sure not to get any surprises, we use the method for the other calls
175 * as well.
176 */
178 asmlinkage int sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
179 struct pt_regs *regs)
180 {
181 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
182 }
184 /* if newusp is 0, we just grab the old usp */
185 /* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
186 asmlinkage int sys_clone(unsigned long newusp, unsigned long flags,
187 int* parent_tid, int* child_tid, long mof, long srp,
188 struct pt_regs *regs)
189 {
190 if (!newusp)
191 newusp = rdusp();
192 return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
193 }
195 /* vfork is a system call in i386 because of register-pressure - maybe
196 * we can remove it and handle it in libc but we put it here until then.
197 */
199 asmlinkage int sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
200 struct pt_regs *regs)
201 {
202 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
203 }
205 /*
206 * sys_execve() executes a new program.
207 */
208 asmlinkage int sys_execve(const char *fname, char **argv, char **envp,
209 long r13, long mof, long srp,
210 struct pt_regs *regs)
211 {
212 int error;
213 char *filename;
215 filename = getname(fname);
216 error = PTR_ERR(filename);
218 if (IS_ERR(filename))
219 goto out;
220 error = do_execve(filename, argv, envp, regs);
221 putname(filename);
222 out:
223 return error;
224 }
226 unsigned long get_wchan(struct task_struct *p)
227 {
228 #if 0
229 /* YURGH. TODO. */
231 unsigned long ebp, esp, eip;
232 unsigned long stack_page;
233 int count = 0;
234 if (!p || p == current || p->state == TASK_RUNNING)
235 return 0;
236 stack_page = (unsigned long)p;
237 esp = p->thread.esp;
238 if (!stack_page || esp < stack_page || esp > 8188+stack_page)
239 return 0;
240 /* include/asm-i386/system.h:switch_to() pushes ebp last. */
241 ebp = *(unsigned long *) esp;
242 do {
243 if (ebp < stack_page || ebp > 8184+stack_page)
244 return 0;
245 eip = *(unsigned long *) (ebp+4);
246 if (!in_sched_functions(eip))
247 return eip;
248 ebp = *(unsigned long *) ebp;
249 } while (count++ < 16);
250 #endif
251 return 0;
252 }
253 #undef last_sched
254 #undef first_sched
256 void show_regs(struct pt_regs * regs)
257 {
258 unsigned long usp = rdusp();
259 printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
260 regs->irp, regs->srp, regs->dccr, usp, regs->mof );
261 printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
262 regs->r0, regs->r1, regs->r2, regs->r3);
263 printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
264 regs->r4, regs->r5, regs->r6, regs->r7);
265 printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
266 regs->r8, regs->r9, regs->r10, regs->r11);
267 printk("r12: %08lx r13: %08lx oR10: %08lx\n",
268 regs->r12, regs->r13, regs->orig_r10);
269 }