uml: throw out CHOOSE_MODE
[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
49 /* This is a per-cpu array.  A processor only modifies its entry and it only
50  * cares about its entry, so it's OK if another processor is modifying its
51  * entry.
52  */
53 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
54
55 static inline int external_pid(struct task_struct *task)
56 {
57         return external_pid_skas(task);
58 }
59
60 int pid_to_processor_id(int pid)
61 {
62         int i;
63
64         for(i = 0; i < ncpus; i++){
65                 if(cpu_tasks[i].pid == pid)
66                         return i;
67         }
68         return -1;
69 }
70
71 void free_stack(unsigned long stack, int order)
72 {
73         free_pages(stack, order);
74 }
75
76 unsigned long alloc_stack(int order, int atomic)
77 {
78         unsigned long page;
79         gfp_t flags = GFP_KERNEL;
80
81         if (atomic)
82                 flags = GFP_ATOMIC;
83         page = __get_free_pages(flags, order);
84         if (page == 0)
85                 return 0;
86
87         return page;
88 }
89
90 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
91 {
92         int pid;
93
94         current->thread.request.u.thread.proc = fn;
95         current->thread.request.u.thread.arg = arg;
96         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
97                       &current->thread.regs, 0, NULL, NULL);
98         return pid;
99 }
100
101 static inline void set_current(struct task_struct *task)
102 {
103         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
104                 { external_pid(task), task });
105 }
106
107 void *_switch_to(void *prev, void *next, void *last)
108 {
109         struct task_struct *from = prev;
110         struct task_struct *to= next;
111
112         to->thread.prev_sched = from;
113         set_current(to);
114
115         do {
116                 current->thread.saved_task = NULL;
117                 switch_to_skas(prev, next);
118                 if(current->thread.saved_task)
119                         show_regs(&(current->thread.regs));
120                 next= current->thread.saved_task;
121                 prev= current;
122         } while(current->thread.saved_task);
123
124         return current->thread.prev_sched;
125
126 }
127
128 void interrupt_end(void)
129 {
130         if(need_resched())
131                 schedule();
132         if(test_tsk_thread_flag(current, TIF_SIGPENDING))
133                 do_signal();
134 }
135
136 void release_thread(struct task_struct *task)
137 {
138         release_thread_skas(task);
139 }
140
141 void exit_thread(void)
142 {
143 }
144
145 void *get_current(void)
146 {
147         return current;
148 }
149
150 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
151                 unsigned long stack_top, struct task_struct * p,
152                 struct pt_regs *regs)
153 {
154         int ret;
155
156         p->thread = (struct thread_struct) INIT_THREAD;
157         ret = copy_thread_skas(nr, clone_flags, sp, stack_top, p, regs);
158
159         if (ret || !current->thread.forking)
160                 goto out;
161
162         clear_flushed_tls(p);
163
164         /*
165          * Set a new TLS for the child thread?
166          */
167         if (clone_flags & CLONE_SETTLS)
168                 ret = arch_copy_tls(p);
169
170 out:
171         return ret;
172 }
173
174 void initial_thread_cb(void (*proc)(void *), void *arg)
175 {
176         int save_kmalloc_ok = kmalloc_ok;
177
178         kmalloc_ok = 0;
179         initial_thread_cb_skas(proc, arg);
180         kmalloc_ok = save_kmalloc_ok;
181 }
182
183 void default_idle(void)
184 {
185         while(1){
186                 /* endless idle loop with no priority at all */
187
188                 /*
189                  * although we are an idle CPU, we do not want to
190                  * get into the scheduler unnecessarily.
191                  */
192                 if(need_resched())
193                         schedule();
194
195                 idle_sleep(10);
196         }
197 }
198
199 void cpu_idle(void)
200 {
201         init_idle_skas();
202 }
203
204 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
205                       pte_t *pte_out)
206 {
207         pgd_t *pgd;
208         pud_t *pud;
209         pmd_t *pmd;
210         pte_t *pte;
211         pte_t ptent;
212
213         if(task->mm == NULL)
214                 return ERR_PTR(-EINVAL);
215         pgd = pgd_offset(task->mm, addr);
216         if(!pgd_present(*pgd))
217                 return ERR_PTR(-EINVAL);
218
219         pud = pud_offset(pgd, addr);
220         if(!pud_present(*pud))
221                 return ERR_PTR(-EINVAL);
222
223         pmd = pmd_offset(pud, addr);
224         if(!pmd_present(*pmd))
225                 return ERR_PTR(-EINVAL);
226
227         pte = pte_offset_kernel(pmd, addr);
228         ptent = *pte;
229         if(!pte_present(ptent))
230                 return ERR_PTR(-EINVAL);
231
232         if(pte_out != NULL)
233                 *pte_out = ptent;
234         return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
235 }
236
237 char *current_cmd(void)
238 {
239 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
240         return "(Unknown)";
241 #else
242         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
243         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
244 #endif
245 }
246
247 void dump_thread(struct pt_regs *regs, struct user *u)
248 {
249 }
250
251 int __cant_sleep(void) {
252         return in_atomic() || irqs_disabled() || in_interrupt();
253         /* Is in_interrupt() really needed? */
254 }
255
256 int user_context(unsigned long sp)
257 {
258         unsigned long stack;
259
260         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
261         return stack != (unsigned long) current_thread;
262 }
263
264 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
265
266 void do_uml_exitcalls(void)
267 {
268         exitcall_t *call;
269
270         call = &__uml_exitcall_end;
271         while (--call >= &__uml_exitcall_begin)
272                 (*call)();
273 }
274
275 char *uml_strdup(char *string)
276 {
277         return kstrdup(string, GFP_KERNEL);
278 }
279
280 int copy_to_user_proc(void __user *to, void *from, int size)
281 {
282         return copy_to_user(to, from, size);
283 }
284
285 int copy_from_user_proc(void *to, void __user *from, int size)
286 {
287         return copy_from_user(to, from, size);
288 }
289
290 int clear_user_proc(void __user *buf, int size)
291 {
292         return clear_user(buf, size);
293 }
294
295 int strlen_user_proc(char __user *str)
296 {
297         return strlen_user(str);
298 }
299
300 int smp_sigio_handler(void)
301 {
302 #ifdef CONFIG_SMP
303         int cpu = current_thread->cpu;
304         IPI_handler(cpu);
305         if(cpu != 0)
306                 return 1;
307 #endif
308         return 0;
309 }
310
311 int cpu(void)
312 {
313         return current_thread->cpu;
314 }
315
316 static atomic_t using_sysemu = ATOMIC_INIT(0);
317 int sysemu_supported;
318
319 void set_using_sysemu(int value)
320 {
321         if (value > sysemu_supported)
322                 return;
323         atomic_set(&using_sysemu, value);
324 }
325
326 int get_using_sysemu(void)
327 {
328         return atomic_read(&using_sysemu);
329 }
330
331 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
332 {
333         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
334                 *eof = 1;
335
336         return strlen(buf);
337 }
338
339 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
340 {
341         char tmp[2];
342
343         if (copy_from_user(tmp, buf, 1))
344                 return -EFAULT;
345
346         if (tmp[0] >= '0' && tmp[0] <= '2')
347                 set_using_sysemu(tmp[0] - '0');
348         return count; /*We use the first char, but pretend to write everything*/
349 }
350
351 int __init make_proc_sysemu(void)
352 {
353         struct proc_dir_entry *ent;
354         if (!sysemu_supported)
355                 return 0;
356
357         ent = create_proc_entry("sysemu", 0600, &proc_root);
358
359         if (ent == NULL)
360         {
361                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
362                 return 0;
363         }
364
365         ent->read_proc  = proc_read_sysemu;
366         ent->write_proc = proc_write_sysemu;
367
368         return 0;
369 }
370
371 late_initcall(make_proc_sysemu);
372
373 int singlestepping(void * t)
374 {
375         struct task_struct *task = t ? t : current;
376
377         if ( ! (task->ptrace & PT_DTRACE) )
378                 return(0);
379
380         if (task->thread.singlestep_syscall)
381                 return(1);
382
383         return 2;
384 }
385
386 /*
387  * Only x86 and x86_64 have an arch_align_stack().
388  * All other arches have "#define arch_align_stack(x) (x)"
389  * in their asm/system.h
390  * As this is included in UML from asm-um/system-generic.h,
391  * we can use it to behave as the subarch does.
392  */
393 #ifndef arch_align_stack
394 unsigned long arch_align_stack(unsigned long sp)
395 {
396         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
397                 sp -= get_random_int() % 8192;
398         return sp & ~0xf;
399 }
400 #endif