Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux...
[~shefty/rdma-dev.git] / arch / m68k / kernel / process_mm.c
1 /*
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
13 #include <linux/errno.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/slab.h>
19 #include <linux/fs.h>
20 #include <linux/smp.h>
21 #include <linux/stddef.h>
22 #include <linux/unistd.h>
23 #include <linux/ptrace.h>
24 #include <linux/user.h>
25 #include <linux/reboot.h>
26 #include <linux/init_task.h>
27 #include <linux/mqueue.h>
28
29 #include <asm/uaccess.h>
30 #include <asm/system.h>
31 #include <asm/traps.h>
32 #include <asm/machdep.h>
33 #include <asm/setup.h>
34 #include <asm/pgtable.h>
35
36
37 asmlinkage void ret_from_fork(void);
38
39
40 /*
41  * Return saved PC from a blocked thread
42  */
43 unsigned long thread_saved_pc(struct task_struct *tsk)
44 {
45         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
46         /* Check whether the thread is blocked in resume() */
47         if (in_sched_functions(sw->retpc))
48                 return ((unsigned long *)sw->a6)[1];
49         else
50                 return sw->retpc;
51 }
52
53 /*
54  * The idle loop on an m68k..
55  */
56 static void default_idle(void)
57 {
58         if (!need_resched())
59 #if defined(MACH_ATARI_ONLY)
60                 /* block out HSYNC on the atari (falcon) */
61                 __asm__("stop #0x2200" : : : "cc");
62 #else
63                 __asm__("stop #0x2000" : : : "cc");
64 #endif
65 }
66
67 void (*idle)(void) = default_idle;
68
69 /*
70  * The idle thread. There's no useful work to be
71  * done, so just try to conserve power and have a
72  * low exit latency (ie sit in a loop waiting for
73  * somebody to say that they'd like to reschedule)
74  */
75 void cpu_idle(void)
76 {
77         /* endless idle loop with no priority at all */
78         while (1) {
79                 while (!need_resched())
80                         idle();
81                 preempt_enable_no_resched();
82                 schedule();
83                 preempt_disable();
84         }
85 }
86
87 void machine_restart(char * __unused)
88 {
89         if (mach_reset)
90                 mach_reset();
91         for (;;);
92 }
93
94 void machine_halt(void)
95 {
96         if (mach_halt)
97                 mach_halt();
98         for (;;);
99 }
100
101 void machine_power_off(void)
102 {
103         if (mach_power_off)
104                 mach_power_off();
105         for (;;);
106 }
107
108 void (*pm_power_off)(void) = machine_power_off;
109 EXPORT_SYMBOL(pm_power_off);
110
111 void show_regs(struct pt_regs * regs)
112 {
113         printk("\n");
114         printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
115                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
116         printk("ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
117                regs->orig_d0, regs->d0, regs->a2, regs->a1);
118         printk("A0: %08lx  D5: %08lx  D4: %08lx\n",
119                regs->a0, regs->d5, regs->d4);
120         printk("D3: %08lx  D2: %08lx  D1: %08lx\n",
121                regs->d3, regs->d2, regs->d1);
122         if (!(regs->sr & PS_S))
123                 printk("USP: %08lx\n", rdusp());
124 }
125
126 /*
127  * Create a kernel thread
128  */
129 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
130 {
131         int pid;
132         mm_segment_t fs;
133
134         fs = get_fs();
135         set_fs (KERNEL_DS);
136
137         {
138         register long retval __asm__ ("d0");
139         register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
140
141         retval = __NR_clone;
142         __asm__ __volatile__
143           ("clrl %%d2\n\t"
144            "trap #0\n\t"                /* Linux/m68k system call */
145            "tstl %0\n\t"                /* child or parent */
146            "jne 1f\n\t"                 /* parent - jump */
147            "lea %%sp@(%c7),%6\n\t"      /* reload current */
148            "movel %6@,%6\n\t"
149            "movel %3,%%sp@-\n\t"        /* push argument */
150            "jsr %4@\n\t"                /* call fn */
151            "movel %0,%%d1\n\t"          /* pass exit value */
152            "movel %2,%%d0\n\t"          /* exit */
153            "trap #0\n"
154            "1:"
155            : "+d" (retval)
156            : "i" (__NR_clone), "i" (__NR_exit),
157              "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
158              "i" (-THREAD_SIZE)
159            : "d2");
160
161         pid = retval;
162         }
163
164         set_fs (fs);
165         return pid;
166 }
167 EXPORT_SYMBOL(kernel_thread);
168
169 void flush_thread(void)
170 {
171         unsigned long zero = 0;
172
173         current->thread.fs = __USER_DS;
174         if (!FPU_IS_EMU)
175                 asm volatile("frestore %0": :"m" (zero));
176 }
177
178 /*
179  * "m68k_fork()".. By the time we get here, the
180  * non-volatile registers have also been saved on the
181  * stack. We do some ugly pointer stuff here.. (see
182  * also copy_thread)
183  */
184
185 asmlinkage int m68k_fork(struct pt_regs *regs)
186 {
187         return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
188 }
189
190 asmlinkage int m68k_vfork(struct pt_regs *regs)
191 {
192         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
193                        NULL, NULL);
194 }
195
196 asmlinkage int m68k_clone(struct pt_regs *regs)
197 {
198         unsigned long clone_flags;
199         unsigned long newsp;
200         int __user *parent_tidptr, *child_tidptr;
201
202         /* syscall2 puts clone_flags in d1 and usp in d2 */
203         clone_flags = regs->d1;
204         newsp = regs->d2;
205         parent_tidptr = (int __user *)regs->d3;
206         child_tidptr = (int __user *)regs->d4;
207         if (!newsp)
208                 newsp = rdusp();
209         return do_fork(clone_flags, newsp, regs, 0,
210                        parent_tidptr, child_tidptr);
211 }
212
213 int copy_thread(unsigned long clone_flags, unsigned long usp,
214                  unsigned long unused,
215                  struct task_struct * p, struct pt_regs * regs)
216 {
217         struct pt_regs * childregs;
218         struct switch_stack * childstack, *stack;
219         unsigned long *retp;
220
221         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
222
223         *childregs = *regs;
224         childregs->d0 = 0;
225
226         retp = ((unsigned long *) regs);
227         stack = ((struct switch_stack *) retp) - 1;
228
229         childstack = ((struct switch_stack *) childregs) - 1;
230         *childstack = *stack;
231         childstack->retpc = (unsigned long)ret_from_fork;
232
233         p->thread.usp = usp;
234         p->thread.ksp = (unsigned long)childstack;
235
236         if (clone_flags & CLONE_SETTLS)
237                 task_thread_info(p)->tp_value = regs->d5;
238
239         /*
240          * Must save the current SFC/DFC value, NOT the value when
241          * the parent was last descheduled - RGH  10-08-96
242          */
243         p->thread.fs = get_fs().seg;
244
245         if (!FPU_IS_EMU) {
246                 /* Copy the current fpu state */
247                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
248
249                 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
250                         if (CPU_IS_COLDFIRE) {
251                                 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
252                                               "fmovel %/fpiar,%1\n\t"
253                                               "fmovel %/fpcr,%2\n\t"
254                                               "fmovel %/fpsr,%3"
255                                               :
256                                               : "m" (p->thread.fp[0]),
257                                                 "m" (p->thread.fpcntl[0]),
258                                                 "m" (p->thread.fpcntl[1]),
259                                                 "m" (p->thread.fpcntl[2])
260                                               : "memory");
261                         } else {
262                                 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
263                                               "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
264                                               :
265                                               : "m" (p->thread.fp[0]),
266                                                 "m" (p->thread.fpcntl[0])
267                                               : "memory");
268                         }
269                 }
270
271                 /* Restore the state in case the fpu was busy */
272                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
273         }
274
275         return 0;
276 }
277
278 /* Fill in the fpu structure for a core dump.  */
279
280 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
281 {
282         char fpustate[216];
283
284         if (FPU_IS_EMU) {
285                 int i;
286
287                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
288                 memcpy(fpu->fpregs, current->thread.fp, 96);
289                 /* Convert internal fpu reg representation
290                  * into long double format
291                  */
292                 for (i = 0; i < 24; i += 3)
293                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
294                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
295                 return 1;
296         }
297
298         /* First dump the fpu context to avoid protocol violation.  */
299         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
300         if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
301                 return 0;
302
303         if (CPU_IS_COLDFIRE) {
304                 asm volatile ("fmovel %/fpiar,%0\n\t"
305                               "fmovel %/fpcr,%1\n\t"
306                               "fmovel %/fpsr,%2\n\t"
307                               "fmovemd %/fp0-%/fp7,%3"
308                               :
309                               : "m" (fpu->fpcntl[0]),
310                                 "m" (fpu->fpcntl[1]),
311                                 "m" (fpu->fpcntl[2]),
312                                 "m" (fpu->fpregs[0])
313                               : "memory");
314         } else {
315                 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
316                               :
317                               : "m" (fpu->fpcntl[0])
318                               : "memory");
319                 asm volatile ("fmovemx %/fp0-%/fp7,%0"
320                               :
321                               : "m" (fpu->fpregs[0])
322                               : "memory");
323         }
324
325         return 1;
326 }
327 EXPORT_SYMBOL(dump_fpu);
328
329 /*
330  * sys_execve() executes a new program.
331  */
332 asmlinkage int sys_execve(const char __user *name,
333                           const char __user *const __user *argv,
334                           const char __user *const __user *envp)
335 {
336         int error;
337         char * filename;
338         struct pt_regs *regs = (struct pt_regs *) &name;
339
340         filename = getname(name);
341         error = PTR_ERR(filename);
342         if (IS_ERR(filename))
343                 return error;
344         error = do_execve(filename, argv, envp, regs);
345         putname(filename);
346         return error;
347 }
348
349 unsigned long get_wchan(struct task_struct *p)
350 {
351         unsigned long fp, pc;
352         unsigned long stack_page;
353         int count = 0;
354         if (!p || p == current || p->state == TASK_RUNNING)
355                 return 0;
356
357         stack_page = (unsigned long)task_stack_page(p);
358         fp = ((struct switch_stack *)p->thread.ksp)->a6;
359         do {
360                 if (fp < stack_page+sizeof(struct thread_info) ||
361                     fp >= 8184+stack_page)
362                         return 0;
363                 pc = ((unsigned long *)fp)[1];
364                 if (!in_sched_functions(pc))
365                         return pc;
366                 fp = *(unsigned long *) fp;
367         } while (count++ < 16);
368         return 0;
369 }