[PATCH] uml: include the linker script rather than symlink it
[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/mm.h"
12 #include "linux/slab.h"
13 #include "linux/utsname.h"
14 #include "linux/fs.h"
15 #include "linux/utime.h"
16 #include "linux/smp_lock.h"
17 #include "linux/module.h"
18 #include "linux/init.h"
19 #include "linux/capability.h"
20 #include "linux/vmalloc.h"
21 #include "linux/spinlock.h"
22 #include "linux/proc_fs.h"
23 #include "linux/ptrace.h"
24 #include "linux/random.h"
25 #include "asm/unistd.h"
26 #include "asm/mman.h"
27 #include "asm/segment.h"
28 #include "asm/stat.h"
29 #include "asm/pgtable.h"
30 #include "asm/processor.h"
31 #include "asm/tlbflush.h"
32 #include "asm/uaccess.h"
33 #include "asm/user.h"
34 #include "user_util.h"
35 #include "kern_util.h"
36 #include "kern.h"
37 #include "signal_kern.h"
38 #include "signal_user.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 "2_5compat.h"
47 #include "os.h"
48 #include "mode.h"
49 #include "mode_kern.h"
50 #include "choose-mode.h"
51
52 /* This is a per-cpu array.  A processor only modifies its entry and it only
53  * cares about its entry, so it's OK if another processor is modifying its
54  * entry.
55  */
56 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
57
58 struct task_struct *get_task(int pid, int require)
59 {
60         struct task_struct *ret;
61
62         read_lock(&tasklist_lock);
63         ret = find_task_by_pid(pid);
64         read_unlock(&tasklist_lock);
65
66         if(require && (ret == NULL)) panic("get_task couldn't find a task\n");
67         return(ret);
68 }
69
70 int external_pid(void *t)
71 {
72         struct task_struct *task = t ? t : current;
73
74         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
75 }
76
77 int pid_to_processor_id(int pid)
78 {
79         int i;
80
81         for(i = 0; i < ncpus; i++){
82                 if(cpu_tasks[i].pid == pid) return(i);
83         }
84         return(-1);
85 }
86
87 void free_stack(unsigned long stack, int order)
88 {
89         free_pages(stack, order);
90 }
91
92 unsigned long alloc_stack(int order, int atomic)
93 {
94         unsigned long page;
95         int flags = GFP_KERNEL;
96
97         if(atomic) flags |= GFP_ATOMIC;
98         page = __get_free_pages(flags, order);
99         if(page == 0)
100                 return(0);
101         stack_protections(page);
102         return(page);
103 }
104
105 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
106 {
107         int pid;
108
109         current->thread.request.u.thread.proc = fn;
110         current->thread.request.u.thread.arg = arg;
111         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, NULL, 0, NULL,
112                       NULL);
113         if(pid < 0)
114                 panic("do_fork failed in kernel_thread, errno = %d", pid);
115         return(pid);
116 }
117
118 void switch_mm(struct mm_struct *prev, struct mm_struct *next, 
119                struct task_struct *tsk)
120 {
121         int cpu = smp_processor_id();
122
123         if (prev != next) 
124                 cpu_clear(cpu, prev->cpu_vm_mask);
125         cpu_set(cpu, next->cpu_vm_mask);
126 }
127
128 void set_current(void *t)
129 {
130         struct task_struct *task = t;
131
132         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task) 
133                 { external_pid(task), task });
134 }
135
136 void *_switch_to(void *prev, void *next, void *last)
137 {
138         return(CHOOSE_MODE(switch_to_tt(prev, next), 
139                            switch_to_skas(prev, next)));
140 }
141
142 void interrupt_end(void)
143 {
144         if(need_resched()) schedule();
145         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
146 }
147
148 void release_thread(struct task_struct *task)
149 {
150         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
151 }
152  
153 void exit_thread(void)
154 {
155         CHOOSE_MODE(exit_thread_tt(), exit_thread_skas());
156         unprotect_stack((unsigned long) current_thread);
157 }
158  
159 void *get_current(void)
160 {
161         return(current);
162 }
163
164 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
165                 unsigned long stack_top, struct task_struct * p, 
166                 struct pt_regs *regs)
167 {
168         p->thread = (struct thread_struct) INIT_THREAD;
169         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr, 
170                                 clone_flags, sp, stack_top, p, regs));
171 }
172
173 void initial_thread_cb(void (*proc)(void *), void *arg)
174 {
175         int save_kmalloc_ok = kmalloc_ok;
176
177         kmalloc_ok = 0;
178         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 
179                          arg);
180         kmalloc_ok = save_kmalloc_ok;
181 }
182  
183 unsigned long stack_sp(unsigned long page)
184 {
185         return(page + PAGE_SIZE - sizeof(void *));
186 }
187
188 int current_pid(void)
189 {
190         return(current->pid);
191 }
192
193 void default_idle(void)
194 {
195         uml_idle_timer();
196
197         atomic_inc(&init_mm.mm_count);
198         current->mm = &init_mm;
199         current->active_mm = &init_mm;
200
201         while(1){
202                 /* endless idle loop with no priority at all */
203                 SET_PRI(current);
204
205                 /*
206                  * although we are an idle CPU, we do not want to
207                  * get into the scheduler unnecessarily.
208                  */
209                 if(need_resched())
210                         schedule();
211                 
212                 idle_sleep(10);
213         }
214 }
215
216 void cpu_idle(void)
217 {
218         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
219 }
220
221 int page_size(void)
222 {
223         return(PAGE_SIZE);
224 }
225
226 unsigned long page_mask(void)
227 {
228         return(PAGE_MASK);
229 }
230
231 void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
232                       pte_t *pte_out)
233 {
234         pgd_t *pgd;
235         pud_t *pud;
236         pmd_t *pmd;
237         pte_t *pte;
238
239         if(task->mm == NULL) 
240                 return(ERR_PTR(-EINVAL));
241         pgd = pgd_offset(task->mm, addr);
242         if(!pgd_present(*pgd))
243                 return(ERR_PTR(-EINVAL));
244
245         pud = pud_offset(pgd, addr);
246         if(!pud_present(*pud))
247                 return(ERR_PTR(-EINVAL));
248
249         pmd = pmd_offset(pud, addr);
250         if(!pmd_present(*pmd)) 
251                 return(ERR_PTR(-EINVAL));
252
253         pte = pte_offset_kernel(pmd, addr);
254         if(!pte_present(*pte)) 
255                 return(ERR_PTR(-EINVAL));
256
257         if(pte_out != NULL)
258                 *pte_out = *pte;
259         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
260 }
261
262 char *current_cmd(void)
263 {
264 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
265         return("(Unknown)");
266 #else
267         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
268         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
269 #endif
270 }
271
272 void force_sigbus(void)
273 {
274         printk(KERN_ERR "Killing pid %d because of a lack of memory\n", 
275                current->pid);
276         lock_kernel();
277         sigaddset(&current->pending.signal, SIGBUS);
278         recalc_sigpending();
279         current->flags |= PF_SIGNALED;
280         do_exit(SIGBUS | 0x80);
281 }
282
283 void dump_thread(struct pt_regs *regs, struct user *u)
284 {
285 }
286
287 void enable_hlt(void)
288 {
289         panic("enable_hlt");
290 }
291
292 EXPORT_SYMBOL(enable_hlt);
293
294 void disable_hlt(void)
295 {
296         panic("disable_hlt");
297 }
298
299 EXPORT_SYMBOL(disable_hlt);
300
301 void *um_kmalloc(int size)
302 {
303         return(kmalloc(size, GFP_KERNEL));
304 }
305
306 void *um_kmalloc_atomic(int size)
307 {
308         return(kmalloc(size, GFP_ATOMIC));
309 }
310
311 void *um_vmalloc(int size)
312 {
313         return(vmalloc(size));
314 }
315
316 unsigned long get_fault_addr(void)
317 {
318         return((unsigned long) current->thread.fault_addr);
319 }
320
321 EXPORT_SYMBOL(get_fault_addr);
322
323 void not_implemented(void)
324 {
325         printk(KERN_DEBUG "Something isn't implemented in here\n");
326 }
327
328 EXPORT_SYMBOL(not_implemented);
329
330 int user_context(unsigned long sp)
331 {
332         unsigned long stack;
333
334         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
335         return(stack != (unsigned long) current_thread);
336 }
337
338 extern void remove_umid_dir(void);
339
340 __uml_exitcall(remove_umid_dir);
341
342 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
343
344 void do_uml_exitcalls(void)
345 {
346         exitcall_t *call;
347
348         call = &__uml_exitcall_end;
349         while (--call >= &__uml_exitcall_begin)
350                 (*call)();
351 }
352
353 char *uml_strdup(char *string)
354 {
355         char *new;
356
357         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
358         if(new == NULL) return(NULL);
359         strcpy(new, string);
360         return(new);
361 }
362
363 void *get_init_task(void)
364 {
365         return(&init_thread_union.thread_info.task);
366 }
367
368 int copy_to_user_proc(void __user *to, void *from, int size)
369 {
370         return(copy_to_user(to, from, size));
371 }
372
373 int copy_from_user_proc(void *to, void __user *from, int size)
374 {
375         return(copy_from_user(to, from, size));
376 }
377
378 int clear_user_proc(void __user *buf, int size)
379 {
380         return(clear_user(buf, size));
381 }
382
383 int strlen_user_proc(char __user *str)
384 {
385         return(strlen_user(str));
386 }
387
388 int smp_sigio_handler(void)
389 {
390 #ifdef CONFIG_SMP
391         int cpu = current_thread->cpu;
392         IPI_handler(cpu);
393         if(cpu != 0)
394                 return(1);
395 #endif
396         return(0);
397 }
398
399 int um_in_interrupt(void)
400 {
401         return(in_interrupt());
402 }
403
404 int cpu(void)
405 {
406         return(current_thread->cpu);
407 }
408
409 static atomic_t using_sysemu = ATOMIC_INIT(0);
410 int sysemu_supported;
411
412 void set_using_sysemu(int value)
413 {
414         if (value > sysemu_supported)
415                 return;
416         atomic_set(&using_sysemu, value);
417 }
418
419 int get_using_sysemu(void)
420 {
421         return atomic_read(&using_sysemu);
422 }
423
424 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
425 {
426         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
427                 *eof = 1;
428
429         return strlen(buf);
430 }
431
432 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
433 {
434         char tmp[2];
435
436         if (copy_from_user(tmp, buf, 1))
437                 return -EFAULT;
438
439         if (tmp[0] >= '0' && tmp[0] <= '2')
440                 set_using_sysemu(tmp[0] - '0');
441         return count; /*We use the first char, but pretend to write everything*/
442 }
443
444 int __init make_proc_sysemu(void)
445 {
446         struct proc_dir_entry *ent;
447         if (!sysemu_supported)
448                 return 0;
449
450         ent = create_proc_entry("sysemu", 0600, &proc_root);
451
452         if (ent == NULL)
453         {
454                 printk("Failed to register /proc/sysemu\n");
455                 return(0);
456         }
457
458         ent->read_proc  = proc_read_sysemu;
459         ent->write_proc = proc_write_sysemu;
460
461         return 0;
462 }
463
464 late_initcall(make_proc_sysemu);
465
466 int singlestepping(void * t)
467 {
468         struct task_struct *task = t ? t : current;
469
470         if ( ! (task->ptrace & PT_DTRACE) )
471                 return(0);
472
473         if (task->thread.singlestep_syscall)
474                 return(1);
475
476         return 2;
477 }
478
479 unsigned long arch_align_stack(unsigned long sp)
480 {
481         if (randomize_va_space)
482                 sp -= get_random_int() % 8192;
483         return sp & ~0xf;
484 }
485
486
487 /*
488  * Overrides for Emacs so that we follow Linus's tabbing style.
489  * Emacs will notice this stuff at the end of the file and automatically
490  * adjust the settings for this buffer only.  This must remain at the end
491  * of the file.
492  * ---------------------------------------------------------------------------
493  * Local variables:
494  * c-file-style: "linux"
495  * End:
496  */