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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/m68k/kernel/process.c
3 *
4 * Copyright (C) 1995 Hamish Macdonald
5 *
6 * 68060 fixes by Jesper Skov
7 */
8
9/*
10 * This file handles the architecture-dependent parts of process handling..
11 */
12
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/errno.h>
14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
Alexey Dobriyan4e950f62007-07-30 02:36:13 +040018#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/smp.h>
20#include <linux/smp_lock.h>
21#include <linux/stddef.h>
22#include <linux/unistd.h>
23#include <linux/ptrace.h>
24#include <linux/slab.h>
25#include <linux/user.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/reboot.h>
27#include <linux/init_task.h>
28#include <linux/mqueue.h>
29
30#include <asm/uaccess.h>
31#include <asm/system.h>
32#include <asm/traps.h>
33#include <asm/machdep.h>
34#include <asm/setup.h>
35#include <asm/pgtable.h>
36
37/*
38 * Initial task/thread structure. Make this a per-architecture thing,
39 * because different architectures tend to have different
40 * alignment requirements and potentially different initial
41 * setup.
42 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070043static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
44static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
Joe Perchesd200c922009-09-20 18:14:13 -040045union thread_union init_thread_union __init_task_data
46 __attribute__((aligned(THREAD_SIZE))) =
47 { INIT_THREAD_INFO(init_task) };
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
49/* initial task structure */
50struct task_struct init_task = INIT_TASK(init_task);
51
52EXPORT_SYMBOL(init_task);
53
54asmlinkage void ret_from_fork(void);
55
56
57/*
58 * Return saved PC from a blocked thread
59 */
60unsigned long thread_saved_pc(struct task_struct *tsk)
61{
62 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
63 /* Check whether the thread is blocked in resume() */
64 if (in_sched_functions(sw->retpc))
65 return ((unsigned long *)sw->a6)[1];
66 else
67 return sw->retpc;
68}
69
70/*
71 * The idle loop on an m68k..
72 */
Adrian Bunkcdb04522006-03-24 03:15:57 -080073static void default_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074{
75 if (!need_resched())
Adrian Bunk29c8a242008-10-13 21:58:59 +020076#if defined(MACH_ATARI_ONLY)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 /* block out HSYNC on the atari (falcon) */
78 __asm__("stop #0x2200" : : : "cc");
79#else
80 __asm__("stop #0x2000" : : : "cc");
81#endif
82}
83
84void (*idle)(void) = default_idle;
85
86/*
87 * The idle thread. There's no useful work to be
88 * done, so just try to conserve power and have a
89 * low exit latency (ie sit in a loop waiting for
90 * somebody to say that they'd like to reschedule)
91 */
92void cpu_idle(void)
93{
94 /* endless idle loop with no priority at all */
95 while (1) {
96 while (!need_resched())
97 idle();
Nick Piggin5bfb5d62005-11-08 21:39:01 -080098 preempt_enable_no_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800100 preempt_disable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 }
102}
103
104void machine_restart(char * __unused)
105{
106 if (mach_reset)
107 mach_reset();
108 for (;;);
109}
110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111void machine_halt(void)
112{
113 if (mach_halt)
114 mach_halt();
115 for (;;);
116}
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118void machine_power_off(void)
119{
120 if (mach_power_off)
121 mach_power_off();
122 for (;;);
123}
124
Al Virocead14d2006-01-18 19:41:35 -0500125void (*pm_power_off)(void) = machine_power_off;
126EXPORT_SYMBOL(pm_power_off);
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128void show_regs(struct pt_regs * regs)
129{
130 printk("\n");
131 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
132 regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
133 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
134 regs->orig_d0, regs->d0, regs->a2, regs->a1);
135 printk("A0: %08lx D5: %08lx D4: %08lx\n",
136 regs->a0, regs->d5, regs->d4);
137 printk("D3: %08lx D2: %08lx D1: %08lx\n",
138 regs->d3, regs->d2, regs->d1);
139 if (!(regs->sr & PS_S))
140 printk("USP: %08lx\n", rdusp());
141}
142
143/*
144 * Create a kernel thread
145 */
146int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
147{
148 int pid;
149 mm_segment_t fs;
150
151 fs = get_fs();
152 set_fs (KERNEL_DS);
153
154 {
155 register long retval __asm__ ("d0");
156 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
157
158 retval = __NR_clone;
159 __asm__ __volatile__
160 ("clrl %%d2\n\t"
161 "trap #0\n\t" /* Linux/m68k system call */
162 "tstl %0\n\t" /* child or parent */
163 "jne 1f\n\t" /* parent - jump */
164 "lea %%sp@(%c7),%6\n\t" /* reload current */
165 "movel %6@,%6\n\t"
166 "movel %3,%%sp@-\n\t" /* push argument */
167 "jsr %4@\n\t" /* call fn */
168 "movel %0,%%d1\n\t" /* pass exit value */
169 "movel %2,%%d0\n\t" /* exit */
170 "trap #0\n"
171 "1:"
172 : "+d" (retval)
173 : "i" (__NR_clone), "i" (__NR_exit),
174 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
175 "i" (-THREAD_SIZE)
176 : "d2");
177
178 pid = retval;
179 }
180
181 set_fs (fs);
182 return pid;
183}
Al Viro2e811482006-10-11 17:28:27 +0100184EXPORT_SYMBOL(kernel_thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186void flush_thread(void)
187{
188 unsigned long zero = 0;
189 set_fs(USER_DS);
190 current->thread.fs = __USER_DS;
191 if (!FPU_IS_EMU)
192 asm volatile (".chip 68k/68881\n\t"
193 "frestore %0@\n\t"
194 ".chip 68k" : : "a" (&zero));
195}
196
197/*
198 * "m68k_fork()".. By the time we get here, the
199 * non-volatile registers have also been saved on the
200 * stack. We do some ugly pointer stuff here.. (see
201 * also copy_thread)
202 */
203
204asmlinkage int m68k_fork(struct pt_regs *regs)
205{
206 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
207}
208
209asmlinkage int m68k_vfork(struct pt_regs *regs)
210{
211 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
212 NULL, NULL);
213}
214
215asmlinkage int m68k_clone(struct pt_regs *regs)
216{
217 unsigned long clone_flags;
218 unsigned long newsp;
Al Viro1e5c3742006-10-11 17:28:07 +0100219 int __user *parent_tidptr, *child_tidptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221 /* syscall2 puts clone_flags in d1 and usp in d2 */
222 clone_flags = regs->d1;
223 newsp = regs->d2;
Al Viro1e5c3742006-10-11 17:28:07 +0100224 parent_tidptr = (int __user *)regs->d3;
225 child_tidptr = (int __user *)regs->d4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 if (!newsp)
227 newsp = rdusp();
228 return do_fork(clone_flags, newsp, regs, 0,
229 parent_tidptr, child_tidptr);
230}
231
Alexey Dobriyan6f2c55b2009-04-02 16:56:59 -0700232int copy_thread(unsigned long clone_flags, unsigned long usp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 unsigned long unused,
234 struct task_struct * p, struct pt_regs * regs)
235{
236 struct pt_regs * childregs;
237 struct switch_stack * childstack, *stack;
Al Viro768595f2006-01-12 01:05:53 -0800238 unsigned long *retp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
Al Viro768595f2006-01-12 01:05:53 -0800240 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242 *childregs = *regs;
243 childregs->d0 = 0;
244
245 retp = ((unsigned long *) regs);
246 stack = ((struct switch_stack *) retp) - 1;
247
248 childstack = ((struct switch_stack *) childregs) - 1;
249 *childstack = *stack;
250 childstack->retpc = (unsigned long)ret_from_fork;
251
252 p->thread.usp = usp;
253 p->thread.ksp = (unsigned long)childstack;
Maxim Kuvyrkov9674cdc2009-12-07 00:24:27 -0800254
255 if (clone_flags & CLONE_SETTLS)
256 task_thread_info(p)->tp_value = regs->d5;
257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 /*
259 * Must save the current SFC/DFC value, NOT the value when
260 * the parent was last descheduled - RGH 10-08-96
261 */
262 p->thread.fs = get_fs().seg;
263
264 if (!FPU_IS_EMU) {
265 /* Copy the current fpu state */
266 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
267
268 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2])
269 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
270 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
271 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
272 : "memory");
273 /* Restore the state in case the fpu was busy */
274 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
275 }
276
277 return 0;
278}
279
280/* Fill in the fpu structure for a core dump. */
281
282int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
283{
284 char fpustate[216];
285
286 if (FPU_IS_EMU) {
287 int i;
288
289 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
290 memcpy(fpu->fpregs, current->thread.fp, 96);
291 /* Convert internal fpu reg representation
292 * into long double format
293 */
294 for (i = 0; i < 24; i += 3)
295 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
296 ((fpu->fpregs[i] & 0x0000ffff) << 16);
297 return 1;
298 }
299
300 /* First dump the fpu context to avoid protocol violation. */
301 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
302 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
303 return 0;
304
305 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
306 :: "m" (fpu->fpcntl[0])
307 : "memory");
308 asm volatile ("fmovemx %/fp0-%/fp7,%0"
309 :: "m" (fpu->fpregs[0])
310 : "memory");
311 return 1;
312}
Al Viro2e811482006-10-11 17:28:27 +0100313EXPORT_SYMBOL(dump_fpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
315/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 * sys_execve() executes a new program.
317 */
Al Viro1e5c3742006-10-11 17:28:07 +0100318asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319{
320 int error;
321 char * filename;
322 struct pt_regs *regs = (struct pt_regs *) &name;
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 filename = getname(name);
325 error = PTR_ERR(filename);
326 if (IS_ERR(filename))
John Kacur87fbaf62009-10-12 23:09:24 +0200327 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 error = do_execve(filename, argv, envp, regs);
329 putname(filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 return error;
331}
332
333unsigned long get_wchan(struct task_struct *p)
334{
335 unsigned long fp, pc;
336 unsigned long stack_page;
337 int count = 0;
338 if (!p || p == current || p->state == TASK_RUNNING)
339 return 0;
340
Al Viro768595f2006-01-12 01:05:53 -0800341 stack_page = (unsigned long)task_stack_page(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 fp = ((struct switch_stack *)p->thread.ksp)->a6;
343 do {
344 if (fp < stack_page+sizeof(struct thread_info) ||
345 fp >= 8184+stack_page)
346 return 0;
347 pc = ((unsigned long *)fp)[1];
348 if (!in_sched_functions(pc))
349 return pc;
350 fp = *(unsigned long *) fp;
351 } while (count++ < 16);
352 return 0;
353}