uml: remove page_size()
[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 static inline int external_pid(struct task_struct *task)
58 {
59         return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task);
60 }
61
62 int pid_to_processor_id(int pid)
63 {
64         int i;
65
66         for(i = 0; i < ncpus; i++){
67                 if(cpu_tasks[i].pid == pid)
68                         return i;
69         }
70         return -1;
71 }
72
73 void free_stack(unsigned long stack, int order)
74 {
75         free_pages(stack, order);
76 }
77
78 unsigned long alloc_stack(int order, int atomic)
79 {
80         unsigned long page;
81         gfp_t flags = GFP_KERNEL;
82
83         if (atomic)
84                 flags = GFP_ATOMIC;
85         page = __get_free_pages(flags, order);
86         if(page == 0)
87                 return 0;
88         stack_protections(page);
89         return page;
90 }
91
92 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
93 {
94         int pid;
95
96         current->thread.request.u.thread.proc = fn;
97         current->thread.request.u.thread.arg = arg;
98         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
99                       &current->thread.regs, 0, NULL, NULL);
100         if(pid < 0)
101                 panic("do_fork failed in kernel_thread, errno = %d", pid);
102         return pid;
103 }
104
105 static inline void set_current(struct task_struct *task)
106 {
107         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
108                 { external_pid(task), task });
109 }
110
111 void *_switch_to(void *prev, void *next, void *last)
112 {
113         struct task_struct *from = prev;
114         struct task_struct *to= next;
115
116         to->thread.prev_sched = from;
117         set_current(to);
118
119         do {
120                 current->thread.saved_task = NULL ;
121                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
122                 if(current->thread.saved_task)
123                         show_regs(&(current->thread.regs));
124                 next= current->thread.saved_task;
125                 prev= current;
126         } while(current->thread.saved_task);
127
128         return current->thread.prev_sched;
129
130 }
131
132 void interrupt_end(void)
133 {
134         if(need_resched())
135                 schedule();
136         if(test_tsk_thread_flag(current, TIF_SIGPENDING))
137                 do_signal();
138 }
139
140 void release_thread(struct task_struct *task)
141 {
142         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
143 }
144
145 void exit_thread(void)
146 {
147         unprotect_stack((unsigned long) current_thread);
148 }
149
150 void *get_current(void)
151 {
152         return current;
153 }
154
155 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
156                 unsigned long stack_top, struct task_struct * p,
157                 struct pt_regs *regs)
158 {
159         int ret;
160
161         p->thread = (struct thread_struct) INIT_THREAD;
162         ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
163                                 clone_flags, sp, stack_top, p, regs);
164
165         if (ret || !current->thread.forking)
166                 goto out;
167
168         clear_flushed_tls(p);
169
170         /*
171          * Set a new TLS for the child thread?
172          */
173         if (clone_flags & CLONE_SETTLS)
174                 ret = arch_copy_tls(p);
175
176 out:
177         return ret;
178 }
179
180 void initial_thread_cb(void (*proc)(void *), void *arg)
181 {
182         int save_kmalloc_ok = kmalloc_ok;
183
184         kmalloc_ok = 0;
185         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
186                          arg);
187         kmalloc_ok = save_kmalloc_ok;
188 }
189
190 #ifdef CONFIG_MODE_TT
191 unsigned long stack_sp(unsigned long page)
192 {
193         return page + PAGE_SIZE - sizeof(void *);
194 }
195 #endif
196
197 void default_idle(void)
198 {
199         CHOOSE_MODE(uml_idle_timer(), (void) 0);
200
201         while(1){
202                 /* endless idle loop with no priority at all */
203
204                 /*
205                  * although we are an idle CPU, we do not want to
206                  * get into the scheduler unnecessarily.
207                  */
208                 if(need_resched())
209                         schedule();
210
211                 idle_sleep(10);
212         }
213 }
214
215 void cpu_idle(void)
216 {
217         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
218 }
219
220 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
221                       pte_t *pte_out)
222 {
223         pgd_t *pgd;
224         pud_t *pud;
225         pmd_t *pmd;
226         pte_t *pte;
227         pte_t ptent;
228
229         if(task->mm == NULL)
230                 return ERR_PTR(-EINVAL);
231         pgd = pgd_offset(task->mm, addr);
232         if(!pgd_present(*pgd))
233                 return ERR_PTR(-EINVAL);
234
235         pud = pud_offset(pgd, addr);
236         if(!pud_present(*pud))
237                 return ERR_PTR(-EINVAL);
238
239         pmd = pmd_offset(pud, addr);
240         if(!pmd_present(*pmd))
241                 return ERR_PTR(-EINVAL);
242
243         pte = pte_offset_kernel(pmd, addr);
244         ptent = *pte;
245         if(!pte_present(ptent))
246                 return ERR_PTR(-EINVAL);
247
248         if(pte_out != NULL)
249                 *pte_out = ptent;
250         return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
251 }
252
253 char *current_cmd(void)
254 {
255 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
256         return "(Unknown)";
257 #else
258         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
259         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
260 #endif
261 }
262
263 void dump_thread(struct pt_regs *regs, struct user *u)
264 {
265 }
266
267 void *um_kmalloc(int size)
268 {
269         return kmalloc(size, GFP_KERNEL);
270 }
271
272 void *um_kmalloc_atomic(int size)
273 {
274         return kmalloc(size, GFP_ATOMIC);
275 }
276
277 void *um_vmalloc(int size)
278 {
279         return vmalloc(size);
280 }
281
282 int __cant_sleep(void) {
283         return in_atomic() || irqs_disabled() || in_interrupt();
284         /* Is in_interrupt() really needed? */
285 }
286
287 int user_context(unsigned long sp)
288 {
289         unsigned long stack;
290
291         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
292         return stack != (unsigned long) current_thread;
293 }
294
295 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
296
297 void do_uml_exitcalls(void)
298 {
299         exitcall_t *call;
300
301         call = &__uml_exitcall_end;
302         while (--call >= &__uml_exitcall_begin)
303                 (*call)();
304 }
305
306 char *uml_strdup(char *string)
307 {
308         return kstrdup(string, GFP_KERNEL);
309 }
310
311 int copy_to_user_proc(void __user *to, void *from, int size)
312 {
313         return copy_to_user(to, from, size);
314 }
315
316 int copy_from_user_proc(void *to, void __user *from, int size)
317 {
318         return copy_from_user(to, from, size);
319 }
320
321 int clear_user_proc(void __user *buf, int size)
322 {
323         return clear_user(buf, size);
324 }
325
326 int strlen_user_proc(char __user *str)
327 {
328         return strlen_user(str);
329 }
330
331 int smp_sigio_handler(void)
332 {
333 #ifdef CONFIG_SMP
334         int cpu = current_thread->cpu;
335         IPI_handler(cpu);
336         if(cpu != 0)
337                 return 1;
338 #endif
339         return 0;
340 }
341
342 int cpu(void)
343 {
344         return current_thread->cpu;
345 }
346
347 static atomic_t using_sysemu = ATOMIC_INIT(0);
348 int sysemu_supported;
349
350 void set_using_sysemu(int value)
351 {
352         if (value > sysemu_supported)
353                 return;
354         atomic_set(&using_sysemu, value);
355 }
356
357 int get_using_sysemu(void)
358 {
359         return atomic_read(&using_sysemu);
360 }
361
362 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
363 {
364         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
365                 *eof = 1;
366
367         return strlen(buf);
368 }
369
370 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
371 {
372         char tmp[2];
373
374         if (copy_from_user(tmp, buf, 1))
375                 return -EFAULT;
376
377         if (tmp[0] >= '0' && tmp[0] <= '2')
378                 set_using_sysemu(tmp[0] - '0');
379         return count; /*We use the first char, but pretend to write everything*/
380 }
381
382 int __init make_proc_sysemu(void)
383 {
384         struct proc_dir_entry *ent;
385         if (!sysemu_supported)
386                 return 0;
387
388         ent = create_proc_entry("sysemu", 0600, &proc_root);
389
390         if (ent == NULL)
391         {
392                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
393                 return 0;
394         }
395
396         ent->read_proc  = proc_read_sysemu;
397         ent->write_proc = proc_write_sysemu;
398
399         return 0;
400 }
401
402 late_initcall(make_proc_sysemu);
403
404 int singlestepping(void * t)
405 {
406         struct task_struct *task = t ? t : current;
407
408         if ( ! (task->ptrace & PT_DTRACE) )
409                 return(0);
410
411         if (task->thread.singlestep_syscall)
412                 return(1);
413
414         return 2;
415 }
416
417 /*
418  * Only x86 and x86_64 have an arch_align_stack().
419  * All other arches have "#define arch_align_stack(x) (x)"
420  * in their asm/system.h
421  * As this is included in UML from asm-um/system-generic.h,
422  * we can use it to behave as the subarch does.
423  */
424 #ifndef arch_align_stack
425 unsigned long arch_align_stack(unsigned long sp)
426 {
427         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
428                 sp -= get_random_int() % 8192;
429         return sp & ~0xf;
430 }
431 #endif