90c9ffafc6591b21eaccc4a8a078b9f51c44c3c8
[linux-2.6.git] / arch / um / kernel / process.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/kernel.h"
8 #include "linux/sched.h"
9 #include "linux/interrupt.h"
10 #include "linux/string.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 "linux/personality.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 "kern_util.h"
36 #include "as-layout.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 "tlb.h"
43 #include "frame_kern.h"
44 #include "sigcontext.h"
45 #include "os.h"
46 #include "mode.h"
47 #include "mode_kern.h"
48 #include "choose-mode.h"
49 #include "um_malloc.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         int ret;
161
162         p->thread = (struct thread_struct) INIT_THREAD;
163         ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
164                                 clone_flags, sp, stack_top, p, regs);
165
166         if (ret || !current->thread.forking)
167                 goto out;
168
169         clear_flushed_tls(p);
170
171         /*
172          * Set a new TLS for the child thread?
173          */
174         if (clone_flags & CLONE_SETTLS)
175                 ret = arch_copy_tls(p);
176
177 out:
178         return ret;
179 }
180
181 void initial_thread_cb(void (*proc)(void *), void *arg)
182 {
183         int save_kmalloc_ok = kmalloc_ok;
184
185         kmalloc_ok = 0;
186         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
187                          arg);
188         kmalloc_ok = save_kmalloc_ok;
189 }
190
191 unsigned long stack_sp(unsigned long page)
192 {
193         return(page + PAGE_SIZE - sizeof(void *));
194 }
195
196 int current_pid(void)
197 {
198         return(current->pid);
199 }
200
201 void default_idle(void)
202 {
203         CHOOSE_MODE(uml_idle_timer(), (void) 0);
204
205         while(1){
206                 /* endless idle loop with no priority at all */
207
208                 /*
209                  * although we are an idle CPU, we do not want to
210                  * get into the scheduler unnecessarily.
211                  */
212                 if(need_resched())
213                         schedule();
214
215                 idle_sleep(10);
216         }
217 }
218
219 void cpu_idle(void)
220 {
221         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
222 }
223
224 int page_size(void)
225 {
226         return(PAGE_SIZE);
227 }
228
229 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
230                       pte_t *pte_out)
231 {
232         pgd_t *pgd;
233         pud_t *pud;
234         pmd_t *pmd;
235         pte_t *pte;
236         pte_t ptent;
237
238         if(task->mm == NULL)
239                 return(ERR_PTR(-EINVAL));
240         pgd = pgd_offset(task->mm, addr);
241         if(!pgd_present(*pgd))
242                 return(ERR_PTR(-EINVAL));
243
244         pud = pud_offset(pgd, addr);
245         if(!pud_present(*pud))
246                 return(ERR_PTR(-EINVAL));
247
248         pmd = pmd_offset(pud, addr);
249         if(!pmd_present(*pmd))
250                 return(ERR_PTR(-EINVAL));
251
252         pte = pte_offset_kernel(pmd, addr);
253         ptent = *pte;
254         if(!pte_present(ptent))
255                 return(ERR_PTR(-EINVAL));
256
257         if(pte_out != NULL)
258                 *pte_out = ptent;
259         return((void *) (pte_val(ptent) & 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 void *um_vmalloc_atomic(int size)
317 {
318         return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL);
319 }
320
321 int __cant_sleep(void) {
322         return in_atomic() || irqs_disabled() || in_interrupt();
323         /* Is in_interrupt() really needed? */
324 }
325
326 unsigned long get_fault_addr(void)
327 {
328         return((unsigned long) current->thread.fault_addr);
329 }
330
331 EXPORT_SYMBOL(get_fault_addr);
332
333 void not_implemented(void)
334 {
335         printk(KERN_DEBUG "Something isn't implemented in here\n");
336 }
337
338 EXPORT_SYMBOL(not_implemented);
339
340 int user_context(unsigned long sp)
341 {
342         unsigned long stack;
343
344         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
345         return(stack != (unsigned long) current_thread);
346 }
347
348 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
349
350 void do_uml_exitcalls(void)
351 {
352         exitcall_t *call;
353
354         call = &__uml_exitcall_end;
355         while (--call >= &__uml_exitcall_begin)
356                 (*call)();
357 }
358
359 char *uml_strdup(char *string)
360 {
361         return kstrdup(string, GFP_KERNEL);
362 }
363
364 int copy_to_user_proc(void __user *to, void *from, int size)
365 {
366         return(copy_to_user(to, from, size));
367 }
368
369 int copy_from_user_proc(void *to, void __user *from, int size)
370 {
371         return(copy_from_user(to, from, size));
372 }
373
374 int clear_user_proc(void __user *buf, int size)
375 {
376         return(clear_user(buf, size));
377 }
378
379 int strlen_user_proc(char __user *str)
380 {
381         return(strlen_user(str));
382 }
383
384 int smp_sigio_handler(void)
385 {
386 #ifdef CONFIG_SMP
387         int cpu = current_thread->cpu;
388         IPI_handler(cpu);
389         if(cpu != 0)
390                 return(1);
391 #endif
392         return(0);
393 }
394
395 int cpu(void)
396 {
397         return(current_thread->cpu);
398 }
399
400 static atomic_t using_sysemu = ATOMIC_INIT(0);
401 int sysemu_supported;
402
403 void set_using_sysemu(int value)
404 {
405         if (value > sysemu_supported)
406                 return;
407         atomic_set(&using_sysemu, value);
408 }
409
410 int get_using_sysemu(void)
411 {
412         return atomic_read(&using_sysemu);
413 }
414
415 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
416 {
417         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
418                 *eof = 1;
419
420         return strlen(buf);
421 }
422
423 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
424 {
425         char tmp[2];
426
427         if (copy_from_user(tmp, buf, 1))
428                 return -EFAULT;
429
430         if (tmp[0] >= '0' && tmp[0] <= '2')
431                 set_using_sysemu(tmp[0] - '0');
432         return count; /*We use the first char, but pretend to write everything*/
433 }
434
435 int __init make_proc_sysemu(void)
436 {
437         struct proc_dir_entry *ent;
438         if (!sysemu_supported)
439                 return 0;
440
441         ent = create_proc_entry("sysemu", 0600, &proc_root);
442
443         if (ent == NULL)
444         {
445                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
446                 return(0);
447         }
448
449         ent->read_proc  = proc_read_sysemu;
450         ent->write_proc = proc_write_sysemu;
451
452         return 0;
453 }
454
455 late_initcall(make_proc_sysemu);
456
457 int singlestepping(void * t)
458 {
459         struct task_struct *task = t ? t : current;
460
461         if ( ! (task->ptrace & PT_DTRACE) )
462                 return(0);
463
464         if (task->thread.singlestep_syscall)
465                 return(1);
466
467         return 2;
468 }
469
470 /*
471  * Only x86 and x86_64 have an arch_align_stack().
472  * All other arches have "#define arch_align_stack(x) (x)"
473  * in their asm/system.h
474  * As this is included in UML from asm-um/system-generic.h,
475  * we can use it to behave as the subarch does.
476  */
477 #ifndef arch_align_stack
478 unsigned long arch_align_stack(unsigned long sp)
479 {
480         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
481                 sp -= get_random_int() % 8192;
482         return sp & ~0xf;
483 }
484 #endif