[PATCH] uml: sparse cleanups
[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 "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 int external_pid(void *t)
57 {
58         struct task_struct *task = t ? t : current;
59
60         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
61 }
62
63 int pid_to_processor_id(int pid)
64 {
65         int i;
66
67         for(i = 0; i < ncpus; i++){
68                 if(cpu_tasks[i].pid == pid) 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 void set_current(void *t)
106 {
107         struct task_struct *task = t;
108
109         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
110                 { external_pid(task), task });
111 }
112
113 void *_switch_to(void *prev, void *next, void *last)
114 {
115         struct task_struct *from = prev;
116         struct task_struct *to= next;
117
118         to->thread.prev_sched = from;
119         set_current(to);
120
121         do {
122                 current->thread.saved_task = NULL ;
123                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
124                 if(current->thread.saved_task)
125                         show_regs(&(current->thread.regs));
126                 next= current->thread.saved_task;
127                 prev= current;
128         } while(current->thread.saved_task);
129
130         return(current->thread.prev_sched);
131
132 }
133
134 void interrupt_end(void)
135 {
136         if(need_resched()) schedule();
137         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) 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         p->thread = (struct thread_struct) INIT_THREAD;
160         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr, 
161                                 clone_flags, sp, stack_top, p, regs));
162 }
163
164 void initial_thread_cb(void (*proc)(void *), void *arg)
165 {
166         int save_kmalloc_ok = kmalloc_ok;
167
168         kmalloc_ok = 0;
169         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 
170                          arg);
171         kmalloc_ok = save_kmalloc_ok;
172 }
173  
174 unsigned long stack_sp(unsigned long page)
175 {
176         return(page + PAGE_SIZE - sizeof(void *));
177 }
178
179 int current_pid(void)
180 {
181         return(current->pid);
182 }
183
184 void default_idle(void)
185 {
186         CHOOSE_MODE(uml_idle_timer(), (void) 0);
187
188         atomic_inc(&init_mm.mm_count);
189         current->mm = &init_mm;
190         current->active_mm = &init_mm;
191
192         while(1){
193                 /* endless idle loop with no priority at all */
194
195                 /*
196                  * although we are an idle CPU, we do not want to
197                  * get into the scheduler unnecessarily.
198                  */
199                 if(need_resched())
200                         schedule();
201                 
202                 idle_sleep(10);
203         }
204 }
205
206 void cpu_idle(void)
207 {
208         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
209 }
210
211 int page_size(void)
212 {
213         return(PAGE_SIZE);
214 }
215
216 void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
217                       pte_t *pte_out)
218 {
219         pgd_t *pgd;
220         pud_t *pud;
221         pmd_t *pmd;
222         pte_t *pte;
223         pte_t ptent;
224
225         if(task->mm == NULL) 
226                 return(ERR_PTR(-EINVAL));
227         pgd = pgd_offset(task->mm, addr);
228         if(!pgd_present(*pgd))
229                 return(ERR_PTR(-EINVAL));
230
231         pud = pud_offset(pgd, addr);
232         if(!pud_present(*pud))
233                 return(ERR_PTR(-EINVAL));
234
235         pmd = pmd_offset(pud, addr);
236         if(!pmd_present(*pmd)) 
237                 return(ERR_PTR(-EINVAL));
238
239         pte = pte_offset_kernel(pmd, addr);
240         ptent = *pte;
241         if(!pte_present(ptent))
242                 return(ERR_PTR(-EINVAL));
243
244         if(pte_out != NULL)
245                 *pte_out = ptent;
246         return((void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK));
247 }
248
249 char *current_cmd(void)
250 {
251 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
252         return("(Unknown)");
253 #else
254         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
255         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
256 #endif
257 }
258
259 void force_sigbus(void)
260 {
261         printk(KERN_ERR "Killing pid %d because of a lack of memory\n", 
262                current->pid);
263         lock_kernel();
264         sigaddset(&current->pending.signal, SIGBUS);
265         recalc_sigpending();
266         current->flags |= PF_SIGNALED;
267         do_exit(SIGBUS | 0x80);
268 }
269
270 void dump_thread(struct pt_regs *regs, struct user *u)
271 {
272 }
273
274 void enable_hlt(void)
275 {
276         panic("enable_hlt");
277 }
278
279 EXPORT_SYMBOL(enable_hlt);
280
281 void disable_hlt(void)
282 {
283         panic("disable_hlt");
284 }
285
286 EXPORT_SYMBOL(disable_hlt);
287
288 void *um_kmalloc(int size)
289 {
290         return kmalloc(size, GFP_KERNEL);
291 }
292
293 void *um_kmalloc_atomic(int size)
294 {
295         return kmalloc(size, GFP_ATOMIC);
296 }
297
298 void *um_vmalloc(int size)
299 {
300         return vmalloc(size);
301 }
302
303 void *um_vmalloc_atomic(int size)
304 {
305         return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL);
306 }
307
308 int __cant_sleep(void) {
309         return in_atomic() || irqs_disabled() || in_interrupt();
310         /* Is in_interrupt() really needed? */
311 }
312
313 unsigned long get_fault_addr(void)
314 {
315         return((unsigned long) current->thread.fault_addr);
316 }
317
318 EXPORT_SYMBOL(get_fault_addr);
319
320 void not_implemented(void)
321 {
322         printk(KERN_DEBUG "Something isn't implemented in here\n");
323 }
324
325 EXPORT_SYMBOL(not_implemented);
326
327 int user_context(unsigned long sp)
328 {
329         unsigned long stack;
330
331         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
332         return(stack != (unsigned long) current_thread);
333 }
334
335 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
336
337 void do_uml_exitcalls(void)
338 {
339         exitcall_t *call;
340
341         call = &__uml_exitcall_end;
342         while (--call >= &__uml_exitcall_begin)
343                 (*call)();
344 }
345
346 char *uml_strdup(char *string)
347 {
348         return kstrdup(string, GFP_KERNEL);
349 }
350
351 int copy_to_user_proc(void __user *to, void *from, int size)
352 {
353         return(copy_to_user(to, from, size));
354 }
355
356 int copy_from_user_proc(void *to, void __user *from, int size)
357 {
358         return(copy_from_user(to, from, size));
359 }
360
361 int clear_user_proc(void __user *buf, int size)
362 {
363         return(clear_user(buf, size));
364 }
365
366 int strlen_user_proc(char __user *str)
367 {
368         return(strlen_user(str));
369 }
370
371 int smp_sigio_handler(void)
372 {
373 #ifdef CONFIG_SMP
374         int cpu = current_thread->cpu;
375         IPI_handler(cpu);
376         if(cpu != 0)
377                 return(1);
378 #endif
379         return(0);
380 }
381
382 int cpu(void)
383 {
384         return(current_thread->cpu);
385 }
386
387 static atomic_t using_sysemu = ATOMIC_INIT(0);
388 int sysemu_supported;
389
390 void set_using_sysemu(int value)
391 {
392         if (value > sysemu_supported)
393                 return;
394         atomic_set(&using_sysemu, value);
395 }
396
397 int get_using_sysemu(void)
398 {
399         return atomic_read(&using_sysemu);
400 }
401
402 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
403 {
404         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
405                 *eof = 1;
406
407         return strlen(buf);
408 }
409
410 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
411 {
412         char tmp[2];
413
414         if (copy_from_user(tmp, buf, 1))
415                 return -EFAULT;
416
417         if (tmp[0] >= '0' && tmp[0] <= '2')
418                 set_using_sysemu(tmp[0] - '0');
419         return count; /*We use the first char, but pretend to write everything*/
420 }
421
422 int __init make_proc_sysemu(void)
423 {
424         struct proc_dir_entry *ent;
425         if (!sysemu_supported)
426                 return 0;
427
428         ent = create_proc_entry("sysemu", 0600, &proc_root);
429
430         if (ent == NULL)
431         {
432                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
433                 return(0);
434         }
435
436         ent->read_proc  = proc_read_sysemu;
437         ent->write_proc = proc_write_sysemu;
438
439         return 0;
440 }
441
442 late_initcall(make_proc_sysemu);
443
444 int singlestepping(void * t)
445 {
446         struct task_struct *task = t ? t : current;
447
448         if ( ! (task->ptrace & PT_DTRACE) )
449                 return(0);
450
451         if (task->thread.singlestep_syscall)
452                 return(1);
453
454         return 2;
455 }
456
457 /*
458  * Only x86 and x86_64 have an arch_align_stack().
459  * All other arches have "#define arch_align_stack(x) (x)"
460  * in their asm/system.h
461  * As this is included in UML from asm-um/system-generic.h,
462  * we can use it to behave as the subarch does.
463  */
464 #ifndef arch_align_stack
465 unsigned long arch_align_stack(unsigned long sp)
466 {
467         if (randomize_va_space)
468                 sp -= get_random_int() % 8192;
469         return sp & ~0xf;
470 }
471 #endif