git.oblomov.eu Git - linux-2.6/blob - 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 "signal_user.h"
  40 #include "init.h"
  41 #include "irq_user.h"
  42 #include "mem_user.h"
  43 #include "time_user.h"
  44 #include "tlb.h"
  45 #include "frame_kern.h"
  46 #include "sigcontext.h"
  47 #include "os.h"
  48 #include "mode.h"
  49 #include "mode_kern.h"
  50 #include "choose-mode.h"
  51
  52 /* This is a per-cpu array.  A processor only modifies its entry and it only
  53  * cares about its entry, so it's OK if another processor is modifying its
  54  * entry.
  55  */
  56 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  57
  58 int external_pid(void *t)
  59 {
  60         struct task_struct *task = t ? t : current;
  61
  62         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  63 }
  64
  65 int pid_to_processor_id(int pid)
  66 {
  67         int i;
  68
  69         for(i = 0; i < ncpus; i++){
  70                 if(cpu_tasks[i].pid == pid) return(i);
  71         }
  72         return(-1);
  73 }
  74
  75 void free_stack(unsigned long stack, int order)
  76 {
  77         free_pages(stack, order);
  78 }
  79
  80 unsigned long alloc_stack(int order, int atomic)
  81 {
  82         unsigned long page;
  83         gfp_t flags = GFP_KERNEL;
  84
  85         if (atomic)
  86                 flags = GFP_ATOMIC;
  87         page = __get_free_pages(flags, order);
  88         if(page == 0)
  89                 return(0);
  90         stack_protections(page);
  91         return(page);
  92 }
  93
  94 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
  95 {
  96         int pid;
  97
  98         current->thread.request.u.thread.proc = fn;
  99         current->thread.request.u.thread.arg = arg;
 100         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
 101                       &current->thread.regs, 0, NULL, NULL);
 102         if(pid < 0)
 103                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 104         return(pid);
 105 }
 106
 107 void set_current(void *t)
 108 {
 109         struct task_struct *task = t;
 110
 111         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 112                 { external_pid(task), task });
 113 }
 114
 115 void *_switch_to(void *prev, void *next, void *last)
 116 {
 117         struct task_struct *from = prev;
 118         struct task_struct *to= next;
 119
 120         to->thread.prev_sched = from;
 121         set_current(to);
 122
 123         do {
 124                 current->thread.saved_task = NULL ;
 125                 CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
 126                 if(current->thread.saved_task)
 127                         show_regs(&(current->thread.regs));
 128                 next= current->thread.saved_task;
 129                 prev= current;
 130         } while(current->thread.saved_task);
 131
 132         return(current->thread.prev_sched);
 133
 134 }
 135
 136 void interrupt_end(void)
 137 {
 138         if(need_resched()) schedule();
 139         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 140 }
 141
 142 void release_thread(struct task_struct *task)
 143 {
 144         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 145 }
 146
 147 void exit_thread(void)
 148 {
 149         unprotect_stack((unsigned long) current_thread);
 150 }
 151
 152 void *get_current(void)
 153 {
 154         return(current);
 155 }
 156
 157 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 158                 unsigned long stack_top, struct task_struct * p,
 159                 struct pt_regs *regs)
 160 {
 161         p->thread = (struct thread_struct) INIT_THREAD;
 162         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 163                                 clone_flags, sp, stack_top, p, regs));
 164 }
 165
 166 void initial_thread_cb(void (*proc)(void *), void *arg)
 167 {
 168         int save_kmalloc_ok = kmalloc_ok;
 169
 170         kmalloc_ok = 0;
 171         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 172                          arg);
 173         kmalloc_ok = save_kmalloc_ok;
 174 }
 175
 176 unsigned long stack_sp(unsigned long page)
 177 {
 178         return(page + PAGE_SIZE - sizeof(void *));
 179 }
 180
 181 int current_pid(void)
 182 {
 183         return(current->pid);
 184 }
 185
 186 void default_idle(void)
 187 {
 188         CHOOSE_MODE(uml_idle_timer(), (void) 0);
 189
 190         atomic_inc(&init_mm.mm_count);
 191         current->mm = &init_mm;
 192         current->active_mm = &init_mm;
 193
 194         while(1){
 195                 /* endless idle loop with no priority at all */
 196
 197                 /*
 198                  * although we are an idle CPU, we do not want to
 199                  * get into the scheduler unnecessarily.
 200                  */
 201                 if(need_resched())
 202                         schedule();
 203
 204                 idle_sleep(10);
 205         }
 206 }
 207
 208 void cpu_idle(void)
 209 {
 210         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 211 }
 212
 213 int page_size(void)
 214 {
 215         return(PAGE_SIZE);
 216 }
 217
 218 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 219                       pte_t *pte_out)
 220 {
 221         pgd_t *pgd;
 222         pud_t *pud;
 223         pmd_t *pmd;
 224         pte_t *pte;
 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         if(!pte_present(*pte))
 242                 return(ERR_PTR(-EINVAL));
 243
 244         if(pte_out != NULL)
 245                 *pte_out = *pte;
 246         return((void *) (pte_val(*pte) & 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 unsigned long get_fault_addr(void)
 304 {
 305         return((unsigned long) current->thread.fault_addr);
 306 }
 307
 308 EXPORT_SYMBOL(get_fault_addr);
 309
 310 void not_implemented(void)
 311 {
 312         printk(KERN_DEBUG "Something isn't implemented in here\n");
 313 }
 314
 315 EXPORT_SYMBOL(not_implemented);
 316
 317 int user_context(unsigned long sp)
 318 {
 319         unsigned long stack;
 320
 321         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 322         return(stack != (unsigned long) current_thread);
 323 }
 324
 325 extern void remove_umid_dir(void);
 326
 327 __uml_exitcall(remove_umid_dir);
 328
 329 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 330
 331 void do_uml_exitcalls(void)
 332 {
 333         exitcall_t *call;
 334
 335         call = &__uml_exitcall_end;
 336         while (--call >= &__uml_exitcall_begin)
 337                 (*call)();
 338 }
 339
 340 char *uml_strdup(char *string)
 341 {
 342         return kstrdup(string, GFP_KERNEL);
 343 }
 344
 345 int copy_to_user_proc(void __user *to, void *from, int size)
 346 {
 347         return(copy_to_user(to, from, size));
 348 }
 349
 350 int copy_from_user_proc(void *to, void __user *from, int size)
 351 {
 352         return(copy_from_user(to, from, size));
 353 }
 354
 355 int clear_user_proc(void __user *buf, int size)
 356 {
 357         return(clear_user(buf, size));
 358 }
 359
 360 int strlen_user_proc(char __user *str)
 361 {
 362         return(strlen_user(str));
 363 }
 364
 365 int smp_sigio_handler(void)
 366 {
 367 #ifdef CONFIG_SMP
 368         int cpu = current_thread->cpu;
 369         IPI_handler(cpu);
 370         if(cpu != 0)
 371                 return(1);
 372 #endif
 373         return(0);
 374 }
 375
 376 int um_in_interrupt(void)
 377 {
 378         return(in_interrupt());
 379 }
 380
 381 int cpu(void)
 382 {
 383         return(current_thread->cpu);
 384 }
 385
 386 static atomic_t using_sysemu = ATOMIC_INIT(0);
 387 int sysemu_supported;
 388
 389 void set_using_sysemu(int value)
 390 {
 391         if (value > sysemu_supported)
 392                 return;
 393         atomic_set(&using_sysemu, value);
 394 }
 395
 396 int get_using_sysemu(void)
 397 {
 398         return atomic_read(&using_sysemu);
 399 }
 400
 401 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 402 {
 403         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 404                 *eof = 1;
 405
 406         return strlen(buf);
 407 }
 408
 409 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 410 {
 411         char tmp[2];
 412
 413         if (copy_from_user(tmp, buf, 1))
 414                 return -EFAULT;
 415
 416         if (tmp[0] >= '0' && tmp[0] <= '2')
 417                 set_using_sysemu(tmp[0] - '0');
 418         return count; /*We use the first char, but pretend to write everything*/
 419 }
 420
 421 int __init make_proc_sysemu(void)
 422 {
 423         struct proc_dir_entry *ent;
 424         if (!sysemu_supported)
 425                 return 0;
 426
 427         ent = create_proc_entry("sysemu", 0600, &proc_root);
 428
 429         if (ent == NULL)
 430         {
 431                 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
 432                 return(0);
 433         }
 434
 435         ent->read_proc  = proc_read_sysemu;
 436         ent->write_proc = proc_write_sysemu;
 437
 438         return 0;
 439 }
 440
 441 late_initcall(make_proc_sysemu);
 442
 443 int singlestepping(void * t)
 444 {
 445         struct task_struct *task = t ? t : current;
 446
 447         if ( ! (task->ptrace & PT_DTRACE) )
 448                 return(0);
 449
 450         if (task->thread.singlestep_syscall)
 451                 return(1);
 452
 453         return 2;
 454 }
 455
 456 /*
 457  * Only x86 and x86_64 have an arch_align_stack().
 458  * All other arches have "#define arch_align_stack(x) (x)"
 459  * in their asm/system.h
 460  * As this is included in UML from asm-um/system-generic.h,
 461  * we can use it to behave as the subarch does.
 462  */
 463 #ifndef arch_align_stack
 464 unsigned long arch_align_stack(unsigned long sp)
 465 {
 466         if (randomize_va_space)
 467                 sp -= get_random_int() % 8192;
 468         return sp & ~0xf;
 469 }
 470 #endif