bfa52f206bb6438d520316db40c70e9a22ca51bb
[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
50 /* This is a per-cpu array.  A processor only modifies its entry and it only
51  * cares about its entry, so it's OK if another processor is modifying its
52  * entry.
53  */
54 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
55
56 static inline int external_pid(struct task_struct *task)
57 {
58         return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task);
59 }
60
61 int pid_to_processor_id(int pid)
62 {
63         int i;
64
65         for(i = 0; i < ncpus; i++){
66                 if(cpu_tasks[i].pid == pid)
67                         return i;
68         }
69         return -1;
70 }
71
72 void free_stack(unsigned long stack, int order)
73 {
74         free_pages(stack, order);
75 }
76
77 unsigned long alloc_stack(int order, int atomic)
78 {
79         unsigned long page;
80         gfp_t flags = GFP_KERNEL;
81
82         if (atomic)
83                 flags = GFP_ATOMIC;
84         page = __get_free_pages(flags, order);
85         if(page == 0)
86                 return 0;
87         stack_protections(page);
88         return page;
89 }
90
91 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
92 {
93         int pid;
94
95         current->thread.request.u.thread.proc = fn;
96         current->thread.request.u.thread.arg = arg;
97         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
98                       &current->thread.regs, 0, NULL, NULL);
99         return pid;
100 }
101
102 static inline void set_current(struct task_struct *task)
103 {
104         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
105                 { external_pid(task), task });
106 }
107
108 void *_switch_to(void *prev, void *next, void *last)
109 {
110         struct task_struct *from = prev;
111         struct task_struct *to= next;
112
113         to->thread.prev_sched = from;
114         set_current(to);
115
116         do {
117                 current->thread.saved_task = NULL ;
118                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
119                 if(current->thread.saved_task)
120                         show_regs(&(current->thread.regs));
121                 next= current->thread.saved_task;
122                 prev= current;
123         } while(current->thread.saved_task);
124
125         return current->thread.prev_sched;
126
127 }
128
129 void interrupt_end(void)
130 {
131         if(need_resched())
132                 schedule();
133         if(test_tsk_thread_flag(current, TIF_SIGPENDING))
134                 do_signal();
135 }
136
137 void release_thread(struct task_struct *task)
138 {
139         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
140 }
141
142 void exit_thread(void)
143 {
144         unprotect_stack((unsigned long) current_thread);
145 }
146
147 void *get_current(void)
148 {
149         return current;
150 }
151
152 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
153                 unsigned long stack_top, struct task_struct * p,
154                 struct pt_regs *regs)
155 {
156         int ret;
157
158         p->thread = (struct thread_struct) INIT_THREAD;
159         ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
160                                 clone_flags, sp, stack_top, p, regs);
161
162         if (ret || !current->thread.forking)
163                 goto out;
164
165         clear_flushed_tls(p);
166
167         /*
168          * Set a new TLS for the child thread?
169          */
170         if (clone_flags & CLONE_SETTLS)
171                 ret = arch_copy_tls(p);
172
173 out:
174         return ret;
175 }
176
177 void initial_thread_cb(void (*proc)(void *), void *arg)
178 {
179         int save_kmalloc_ok = kmalloc_ok;
180
181         kmalloc_ok = 0;
182         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
183                          arg);
184         kmalloc_ok = save_kmalloc_ok;
185 }
186
187 #ifdef CONFIG_MODE_TT
188 unsigned long stack_sp(unsigned long page)
189 {
190         return page + PAGE_SIZE - sizeof(void *);
191 }
192 #endif
193
194 void default_idle(void)
195 {
196         CHOOSE_MODE(uml_idle_timer(), (void) 0);
197
198         while(1){
199                 /* endless idle loop with no priority at all */
200
201                 /*
202                  * although we are an idle CPU, we do not want to
203                  * get into the scheduler unnecessarily.
204                  */
205                 if(need_resched())
206                         schedule();
207
208                 idle_sleep(10);
209         }
210 }
211
212 void cpu_idle(void)
213 {
214         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
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 dump_thread(struct pt_regs *regs, struct user *u)
261 {
262 }
263
264 int __cant_sleep(void) {
265         return in_atomic() || irqs_disabled() || in_interrupt();
266         /* Is in_interrupt() really needed? */
267 }
268
269 int user_context(unsigned long sp)
270 {
271         unsigned long stack;
272
273         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
274         return stack != (unsigned long) current_thread;
275 }
276
277 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
278
279 void do_uml_exitcalls(void)
280 {
281         exitcall_t *call;
282
283         call = &__uml_exitcall_end;
284         while (--call >= &__uml_exitcall_begin)
285                 (*call)();
286 }
287
288 char *uml_strdup(char *string)
289 {
290         return kstrdup(string, GFP_KERNEL);
291 }
292
293 int copy_to_user_proc(void __user *to, void *from, int size)
294 {
295         return copy_to_user(to, from, size);
296 }
297
298 int copy_from_user_proc(void *to, void __user *from, int size)
299 {
300         return copy_from_user(to, from, size);
301 }
302
303 int clear_user_proc(void __user *buf, int size)
304 {
305         return clear_user(buf, size);
306 }
307
308 int strlen_user_proc(char __user *str)
309 {
310         return strlen_user(str);
311 }
312
313 int smp_sigio_handler(void)
314 {
315 #ifdef CONFIG_SMP
316         int cpu = current_thread->cpu;
317         IPI_handler(cpu);
318         if(cpu != 0)
319                 return 1;
320 #endif
321         return 0;
322 }
323
324 int cpu(void)
325 {
326         return current_thread->cpu;
327 }
328
329 static atomic_t using_sysemu = ATOMIC_INIT(0);
330 int sysemu_supported;
331
332 void set_using_sysemu(int value)
333 {
334         if (value > sysemu_supported)
335                 return;
336         atomic_set(&using_sysemu, value);
337 }
338
339 int get_using_sysemu(void)
340 {
341         return atomic_read(&using_sysemu);
342 }
343
344 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
345 {
346         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
347                 *eof = 1;
348
349         return strlen(buf);
350 }
351
352 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
353 {
354         char tmp[2];
355
356         if (copy_from_user(tmp, buf, 1))
357                 return -EFAULT;
358
359         if (tmp[0] >= '0' && tmp[0] <= '2')
360                 set_using_sysemu(tmp[0] - '0');
361         return count; /*We use the first char, but pretend to write everything*/
362 }
363
364 int __init make_proc_sysemu(void)
365 {
366         struct proc_dir_entry *ent;
367         if (!sysemu_supported)
368                 return 0;
369
370         ent = create_proc_entry("sysemu", 0600, &proc_root);
371
372         if (ent == NULL)
373         {
374                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
375                 return 0;
376         }
377
378         ent->read_proc  = proc_read_sysemu;
379         ent->write_proc = proc_write_sysemu;
380
381         return 0;
382 }
383
384 late_initcall(make_proc_sysemu);
385
386 int singlestepping(void * t)
387 {
388         struct task_struct *task = t ? t : current;
389
390         if ( ! (task->ptrace & PT_DTRACE) )
391                 return(0);
392
393         if (task->thread.singlestep_syscall)
394                 return(1);
395
396         return 2;
397 }
398
399 /*
400  * Only x86 and x86_64 have an arch_align_stack().
401  * All other arches have "#define arch_align_stack(x) (x)"
402  * in their asm/system.h
403  * As this is included in UML from asm-um/system-generic.h,
404  * we can use it to behave as the subarch does.
405  */
406 #ifndef arch_align_stack
407 unsigned long arch_align_stack(unsigned long sp)
408 {
409         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
410                 sp -= get_random_int() % 8192;
411         return sp & ~0xf;
412 }
413 #endif