Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge
[linux-2.6] / arch / um / kernel / process_kern.c
1 /* 
2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Copyright 2003 PathScale, Inc.
4  * Licensed under the GPL
5  */
6
7 #include "linux/config.h"
8 #include "linux/kernel.h"
9 #include "linux/sched.h"
10 #include "linux/interrupt.h"
11 #include "linux/string.h"
12 #include "linux/mm.h"
13 #include "linux/slab.h"
14 #include "linux/utsname.h"
15 #include "linux/fs.h"
16 #include "linux/utime.h"
17 #include "linux/smp_lock.h"
18 #include "linux/module.h"
19 #include "linux/init.h"
20 #include "linux/capability.h"
21 #include "linux/vmalloc.h"
22 #include "linux/spinlock.h"
23 #include "linux/proc_fs.h"
24 #include "linux/ptrace.h"
25 #include "linux/random.h"
26 #include "asm/unistd.h"
27 #include "asm/mman.h"
28 #include "asm/segment.h"
29 #include "asm/stat.h"
30 #include "asm/pgtable.h"
31 #include "asm/processor.h"
32 #include "asm/tlbflush.h"
33 #include "asm/uaccess.h"
34 #include "asm/user.h"
35 #include "user_util.h"
36 #include "kern_util.h"
37 #include "kern.h"
38 #include "signal_kern.h"
39 #include "init.h"
40 #include "irq_user.h"
41 #include "mem_user.h"
42 #include "time_user.h"
43 #include "tlb.h"
44 #include "frame_kern.h"
45 #include "sigcontext.h"
46 #include "os.h"
47 #include "mode.h"
48 #include "mode_kern.h"
49 #include "choose-mode.h"
50
51 /* This is a per-cpu array.  A processor only modifies its entry and it only
52  * cares about its entry, so it's OK if another processor is modifying its
53  * entry.
54  */
55 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
56
57 int external_pid(void *t)
58 {
59         struct task_struct *task = t ? t : current;
60
61         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
62 }
63
64 int pid_to_processor_id(int pid)
65 {
66         int i;
67
68         for(i = 0; i < ncpus; i++){
69                 if(cpu_tasks[i].pid == pid) return(i);
70         }
71         return(-1);
72 }
73
74 void free_stack(unsigned long stack, int order)
75 {
76         free_pages(stack, order);
77 }
78
79 unsigned long alloc_stack(int order, int atomic)
80 {
81         unsigned long page;
82         gfp_t flags = GFP_KERNEL;
83
84         if (atomic)
85                 flags = GFP_ATOMIC;
86         page = __get_free_pages(flags, order);
87         if(page == 0)
88                 return(0);
89         stack_protections(page);
90         return(page);
91 }
92
93 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
94 {
95         int pid;
96
97         current->thread.request.u.thread.proc = fn;
98         current->thread.request.u.thread.arg = arg;
99         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
100                       &current->thread.regs, 0, NULL, NULL);
101         if(pid < 0)
102                 panic("do_fork failed in kernel_thread, errno = %d", pid);
103         return(pid);
104 }
105
106 void set_current(void *t)
107 {
108         struct task_struct *task = t;
109
110         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
111                 { external_pid(task), task });
112 }
113
114 void *_switch_to(void *prev, void *next, void *last)
115 {
116         struct task_struct *from = prev;
117         struct task_struct *to= next;
118
119         to->thread.prev_sched = from;
120         set_current(to);
121
122         do {
123                 current->thread.saved_task = NULL ;
124                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
125                 if(current->thread.saved_task)
126                         show_regs(&(current->thread.regs));
127                 next= current->thread.saved_task;
128                 prev= current;
129         } while(current->thread.saved_task);
130
131         return(current->thread.prev_sched);
132
133 }
134
135 void interrupt_end(void)
136 {
137         if(need_resched()) schedule();
138         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
139 }
140
141 void release_thread(struct task_struct *task)
142 {
143         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
144 }
145  
146 void exit_thread(void)
147 {
148         unprotect_stack((unsigned long) current_thread);
149 }
150  
151 void *get_current(void)
152 {
153         return(current);
154 }
155
156 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
157                 unsigned long stack_top, struct task_struct * p, 
158                 struct pt_regs *regs)
159 {
160         p->thread = (struct thread_struct) INIT_THREAD;
161         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr, 
162                                 clone_flags, sp, stack_top, p, regs));
163 }
164
165 void initial_thread_cb(void (*proc)(void *), void *arg)
166 {
167         int save_kmalloc_ok = kmalloc_ok;
168
169         kmalloc_ok = 0;
170         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 
171                          arg);
172         kmalloc_ok = save_kmalloc_ok;
173 }
174  
175 unsigned long stack_sp(unsigned long page)
176 {
177         return(page + PAGE_SIZE - sizeof(void *));
178 }
179
180 int current_pid(void)
181 {
182         return(current->pid);
183 }
184
185 void default_idle(void)
186 {
187         CHOOSE_MODE(uml_idle_timer(), (void) 0);
188
189         atomic_inc(&init_mm.mm_count);
190         current->mm = &init_mm;
191         current->active_mm = &init_mm;
192
193         while(1){
194                 /* endless idle loop with no priority at all */
195
196                 /*
197                  * although we are an idle CPU, we do not want to
198                  * get into the scheduler unnecessarily.
199                  */
200                 if(need_resched())
201                         schedule();
202                 
203                 idle_sleep(10);
204         }
205 }
206
207 void cpu_idle(void)
208 {
209         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
210 }
211
212 int page_size(void)
213 {
214         return(PAGE_SIZE);
215 }
216
217 void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
218                       pte_t *pte_out)
219 {
220         pgd_t *pgd;
221         pud_t *pud;
222         pmd_t *pmd;
223         pte_t *pte;
224         pte_t ptent;
225
226         if(task->mm == NULL) 
227                 return(ERR_PTR(-EINVAL));
228         pgd = pgd_offset(task->mm, addr);
229         if(!pgd_present(*pgd))
230                 return(ERR_PTR(-EINVAL));
231
232         pud = pud_offset(pgd, addr);
233         if(!pud_present(*pud))
234                 return(ERR_PTR(-EINVAL));
235
236         pmd = pmd_offset(pud, addr);
237         if(!pmd_present(*pmd)) 
238                 return(ERR_PTR(-EINVAL));
239
240         pte = pte_offset_kernel(pmd, addr);
241         ptent = *pte;
242         if(!pte_present(ptent))
243                 return(ERR_PTR(-EINVAL));
244
245         if(pte_out != NULL)
246                 *pte_out = ptent;
247         return((void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK));
248 }
249
250 char *current_cmd(void)
251 {
252 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
253         return("(Unknown)");
254 #else
255         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
256         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
257 #endif
258 }
259
260 void force_sigbus(void)
261 {
262         printk(KERN_ERR "Killing pid %d because of a lack of memory\n", 
263                current->pid);
264         lock_kernel();
265         sigaddset(&current->pending.signal, SIGBUS);
266         recalc_sigpending();
267         current->flags |= PF_SIGNALED;
268         do_exit(SIGBUS | 0x80);
269 }
270
271 void dump_thread(struct pt_regs *regs, struct user *u)
272 {
273 }
274
275 void enable_hlt(void)
276 {
277         panic("enable_hlt");
278 }
279
280 EXPORT_SYMBOL(enable_hlt);
281
282 void disable_hlt(void)
283 {
284         panic("disable_hlt");
285 }
286
287 EXPORT_SYMBOL(disable_hlt);
288
289 void *um_kmalloc(int size)
290 {
291         return(kmalloc(size, GFP_KERNEL));
292 }
293
294 void *um_kmalloc_atomic(int size)
295 {
296         return(kmalloc(size, GFP_ATOMIC));
297 }
298
299 void *um_vmalloc(int size)
300 {
301         return(vmalloc(size));
302 }
303
304 unsigned long get_fault_addr(void)
305 {
306         return((unsigned long) current->thread.fault_addr);
307 }
308
309 EXPORT_SYMBOL(get_fault_addr);
310
311 void not_implemented(void)
312 {
313         printk(KERN_DEBUG "Something isn't implemented in here\n");
314 }
315
316 EXPORT_SYMBOL(not_implemented);
317
318 int user_context(unsigned long sp)
319 {
320         unsigned long stack;
321
322         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
323         return(stack != (unsigned long) current_thread);
324 }
325
326 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
327
328 void do_uml_exitcalls(void)
329 {
330         exitcall_t *call;
331
332         call = &__uml_exitcall_end;
333         while (--call >= &__uml_exitcall_begin)
334                 (*call)();
335 }
336
337 char *uml_strdup(char *string)
338 {
339         return kstrdup(string, GFP_KERNEL);
340 }
341
342 int copy_to_user_proc(void __user *to, void *from, int size)
343 {
344         return(copy_to_user(to, from, size));
345 }
346
347 int copy_from_user_proc(void *to, void __user *from, int size)
348 {
349         return(copy_from_user(to, from, size));
350 }
351
352 int clear_user_proc(void __user *buf, int size)
353 {
354         return(clear_user(buf, size));
355 }
356
357 int strlen_user_proc(char __user *str)
358 {
359         return(strlen_user(str));
360 }
361
362 int smp_sigio_handler(void)
363 {
364 #ifdef CONFIG_SMP
365         int cpu = current_thread->cpu;
366         IPI_handler(cpu);
367         if(cpu != 0)
368                 return(1);
369 #endif
370         return(0);
371 }
372
373 int um_in_interrupt(void)
374 {
375         return(in_interrupt());
376 }
377
378 int cpu(void)
379 {
380         return(current_thread->cpu);
381 }
382
383 static atomic_t using_sysemu = ATOMIC_INIT(0);
384 int sysemu_supported;
385
386 void set_using_sysemu(int value)
387 {
388         if (value > sysemu_supported)
389                 return;
390         atomic_set(&using_sysemu, value);
391 }
392
393 int get_using_sysemu(void)
394 {
395         return atomic_read(&using_sysemu);
396 }
397
398 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
399 {
400         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
401                 *eof = 1;
402
403         return strlen(buf);
404 }
405
406 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
407 {
408         char tmp[2];
409
410         if (copy_from_user(tmp, buf, 1))
411                 return -EFAULT;
412
413         if (tmp[0] >= '0' && tmp[0] <= '2')
414                 set_using_sysemu(tmp[0] - '0');
415         return count; /*We use the first char, but pretend to write everything*/
416 }
417
418 int __init make_proc_sysemu(void)
419 {
420         struct proc_dir_entry *ent;
421         if (!sysemu_supported)
422                 return 0;
423
424         ent = create_proc_entry("sysemu", 0600, &proc_root);
425
426         if (ent == NULL)
427         {
428                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
429                 return(0);
430         }
431
432         ent->read_proc  = proc_read_sysemu;
433         ent->write_proc = proc_write_sysemu;
434
435         return 0;
436 }
437
438 late_initcall(make_proc_sysemu);
439
440 int singlestepping(void * t)
441 {
442         struct task_struct *task = t ? t : current;
443
444         if ( ! (task->ptrace & PT_DTRACE) )
445                 return(0);
446
447         if (task->thread.singlestep_syscall)
448                 return(1);
449
450         return 2;
451 }
452
453 /*
454  * Only x86 and x86_64 have an arch_align_stack().
455  * All other arches have "#define arch_align_stack(x) (x)"
456  * in their asm/system.h
457  * As this is included in UML from asm-um/system-generic.h,
458  * we can use it to behave as the subarch does.
459  */
460 #ifndef arch_align_stack
461 unsigned long arch_align_stack(unsigned long sp)
462 {
463         if (randomize_va_space)
464                 sp -= get_random_int() % 8192;
465         return sp & ~0xf;
466 }
467 #endif