0c57bc6e37472947c7e499c9ba30d6360b0cc11e
[linux-2.6.git] / 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 "signal_user.h"
40 #include "init.h"
41 #include "irq_user.h"
42 #include "mem_user.h"
43 #include "time_user.h"
44 #include "tlb.h"
45 #include "frame_kern.h"
46 #include "sigcontext.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 int external_pid(void *t)
59 {
60         struct task_struct *task = t ? t : current;
61
62         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
63 }
64
65 int pid_to_processor_id(int pid)
66 {
67         int i;
68
69         for(i = 0; i < ncpus; i++){
70                 if(cpu_tasks[i].pid == pid) return(i);
71         }
72         return(-1);
73 }
74
75 void free_stack(unsigned long stack, int order)
76 {
77         free_pages(stack, order);
78 }
79
80 unsigned long alloc_stack(int order, int atomic)
81 {
82         unsigned long page;
83         int flags = GFP_KERNEL;
84
85         if(atomic) 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->cpu] = ((struct cpu_task) 
111                 { external_pid(task), task });
112 }
113
114 void *_switch_to(void *prev, void *next, void *last)
115 {
116         return(CHOOSE_MODE(switch_to_tt(prev, next), 
117                            switch_to_skas(prev, next)));
118 }
119
120 void interrupt_end(void)
121 {
122         if(need_resched()) schedule();
123         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
124 }
125
126 void release_thread(struct task_struct *task)
127 {
128         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
129 }
130  
131 void exit_thread(void)
132 {
133         unprotect_stack((unsigned long) current_thread);
134 }
135  
136 void *get_current(void)
137 {
138         return(current);
139 }
140
141 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
142                 unsigned long stack_top, struct task_struct * p, 
143                 struct pt_regs *regs)
144 {
145         p->thread = (struct thread_struct) INIT_THREAD;
146         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr, 
147                                 clone_flags, sp, stack_top, p, regs));
148 }
149
150 void initial_thread_cb(void (*proc)(void *), void *arg)
151 {
152         int save_kmalloc_ok = kmalloc_ok;
153
154         kmalloc_ok = 0;
155         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 
156                          arg);
157         kmalloc_ok = save_kmalloc_ok;
158 }
159  
160 unsigned long stack_sp(unsigned long page)
161 {
162         return(page + PAGE_SIZE - sizeof(void *));
163 }
164
165 int current_pid(void)
166 {
167         return(current->pid);
168 }
169
170 void default_idle(void)
171 {
172         uml_idle_timer();
173
174         atomic_inc(&init_mm.mm_count);
175         current->mm = &init_mm;
176         current->active_mm = &init_mm;
177
178         while(1){
179                 /* endless idle loop with no priority at all */
180
181                 /*
182                  * although we are an idle CPU, we do not want to
183                  * get into the scheduler unnecessarily.
184                  */
185                 if(need_resched())
186                         schedule();
187                 
188                 idle_sleep(10);
189         }
190 }
191
192 void cpu_idle(void)
193 {
194         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
195 }
196
197 int page_size(void)
198 {
199         return(PAGE_SIZE);
200 }
201
202 void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
203                       pte_t *pte_out)
204 {
205         pgd_t *pgd;
206         pud_t *pud;
207         pmd_t *pmd;
208         pte_t *pte;
209
210         if(task->mm == NULL) 
211                 return(ERR_PTR(-EINVAL));
212         pgd = pgd_offset(task->mm, addr);
213         if(!pgd_present(*pgd))
214                 return(ERR_PTR(-EINVAL));
215
216         pud = pud_offset(pgd, addr);
217         if(!pud_present(*pud))
218                 return(ERR_PTR(-EINVAL));
219
220         pmd = pmd_offset(pud, addr);
221         if(!pmd_present(*pmd)) 
222                 return(ERR_PTR(-EINVAL));
223
224         pte = pte_offset_kernel(pmd, addr);
225         if(!pte_present(*pte)) 
226                 return(ERR_PTR(-EINVAL));
227
228         if(pte_out != NULL)
229                 *pte_out = *pte;
230         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
231 }
232
233 char *current_cmd(void)
234 {
235 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
236         return("(Unknown)");
237 #else
238         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
239         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
240 #endif
241 }
242
243 void force_sigbus(void)
244 {
245         printk(KERN_ERR "Killing pid %d because of a lack of memory\n", 
246                current->pid);
247         lock_kernel();
248         sigaddset(&current->pending.signal, SIGBUS);
249         recalc_sigpending();
250         current->flags |= PF_SIGNALED;
251         do_exit(SIGBUS | 0x80);
252 }
253
254 void dump_thread(struct pt_regs *regs, struct user *u)
255 {
256 }
257
258 void enable_hlt(void)
259 {
260         panic("enable_hlt");
261 }
262
263 EXPORT_SYMBOL(enable_hlt);
264
265 void disable_hlt(void)
266 {
267         panic("disable_hlt");
268 }
269
270 EXPORT_SYMBOL(disable_hlt);
271
272 void *um_kmalloc(int size)
273 {
274         return(kmalloc(size, GFP_KERNEL));
275 }
276
277 void *um_kmalloc_atomic(int size)
278 {
279         return(kmalloc(size, GFP_ATOMIC));
280 }
281
282 void *um_vmalloc(int size)
283 {
284         return(vmalloc(size));
285 }
286
287 unsigned long get_fault_addr(void)
288 {
289         return((unsigned long) current->thread.fault_addr);
290 }
291
292 EXPORT_SYMBOL(get_fault_addr);
293
294 void not_implemented(void)
295 {
296         printk(KERN_DEBUG "Something isn't implemented in here\n");
297 }
298
299 EXPORT_SYMBOL(not_implemented);
300
301 int user_context(unsigned long sp)
302 {
303         unsigned long stack;
304
305         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
306         return(stack != (unsigned long) current_thread);
307 }
308
309 extern void remove_umid_dir(void);
310
311 __uml_exitcall(remove_umid_dir);
312
313 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
314
315 void do_uml_exitcalls(void)
316 {
317         exitcall_t *call;
318
319         call = &__uml_exitcall_end;
320         while (--call >= &__uml_exitcall_begin)
321                 (*call)();
322 }
323
324 char *uml_strdup(char *string)
325 {
326         return kstrdup(string, GFP_KERNEL);
327 }
328
329 int copy_to_user_proc(void __user *to, void *from, int size)
330 {
331         return(copy_to_user(to, from, size));
332 }
333
334 int copy_from_user_proc(void *to, void __user *from, int size)
335 {
336         return(copy_from_user(to, from, size));
337 }
338
339 int clear_user_proc(void __user *buf, int size)
340 {
341         return(clear_user(buf, size));
342 }
343
344 int strlen_user_proc(char __user *str)
345 {
346         return(strlen_user(str));
347 }
348
349 int smp_sigio_handler(void)
350 {
351 #ifdef CONFIG_SMP
352         int cpu = current_thread->cpu;
353         IPI_handler(cpu);
354         if(cpu != 0)
355                 return(1);
356 #endif
357         return(0);
358 }
359
360 int um_in_interrupt(void)
361 {
362         return(in_interrupt());
363 }
364
365 int cpu(void)
366 {
367         return(current_thread->cpu);
368 }
369
370 static atomic_t using_sysemu = ATOMIC_INIT(0);
371 int sysemu_supported;
372
373 void set_using_sysemu(int value)
374 {
375         if (value > sysemu_supported)
376                 return;
377         atomic_set(&using_sysemu, value);
378 }
379
380 int get_using_sysemu(void)
381 {
382         return atomic_read(&using_sysemu);
383 }
384
385 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
386 {
387         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
388                 *eof = 1;
389
390         return strlen(buf);
391 }
392
393 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
394 {
395         char tmp[2];
396
397         if (copy_from_user(tmp, buf, 1))
398                 return -EFAULT;
399
400         if (tmp[0] >= '0' && tmp[0] <= '2')
401                 set_using_sysemu(tmp[0] - '0');
402         return count; /*We use the first char, but pretend to write everything*/
403 }
404
405 int __init make_proc_sysemu(void)
406 {
407         struct proc_dir_entry *ent;
408         if (!sysemu_supported)
409                 return 0;
410
411         ent = create_proc_entry("sysemu", 0600, &proc_root);
412
413         if (ent == NULL)
414         {
415                 printk("Failed to register /proc/sysemu\n");
416                 return(0);
417         }
418
419         ent->read_proc  = proc_read_sysemu;
420         ent->write_proc = proc_write_sysemu;
421
422         return 0;
423 }
424
425 late_initcall(make_proc_sysemu);
426
427 int singlestepping(void * t)
428 {
429         struct task_struct *task = t ? t : current;
430
431         if ( ! (task->ptrace & PT_DTRACE) )
432                 return(0);
433
434         if (task->thread.singlestep_syscall)
435                 return(1);
436
437         return 2;
438 }
439
440 /*
441  * Only x86 and x86_64 have an arch_align_stack().
442  * All other arches have "#define arch_align_stack(x) (x)"
443  * in their asm/system.h
444  * As this is included in UML from asm-um/system-generic.h,
445  * we can use it to behave as the subarch does.
446  */
447 #ifndef arch_align_stack
448 unsigned long arch_align_stack(unsigned long sp)
449 {
450         if (randomize_va_space)
451                 sp -= get_random_int() % 8192;
452         return sp & ~0xf;
453 }
454 #endif