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/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/vs_cvirt.h"
  25
  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 "2_5compat.h"
  48 #include "os.h"
  49 #include "mode.h"
  50 #include "mode_kern.h"
  51 #include "choose-mode.h"
  52
  53 /* This is a per-cpu array.  A processor only modifies its entry and it only
  54  * cares about its entry, so it's OK if another processor is modifying its
  55  * entry.
  56  */
  57 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  58
  59 struct task_struct *get_task(int pid, int require)
  60 {
  61         struct task_struct *ret;
  62
  63         read_lock(&tasklist_lock);
  64         ret = find_task_by_pid(pid);
  65         read_unlock(&tasklist_lock);
  66
  67         if(require && (ret == NULL)) panic("get_task couldn't find a task\n");
  68         return(ret);
  69 }
  70
  71 int external_pid(void *t)
  72 {
  73         struct task_struct *task = t ? t : current;
  74
  75         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  76 }
  77
  78 int pid_to_processor_id(int pid)
  79 {
  80         int i;
  81
  82         for(i = 0; i < ncpus; i++){
  83                 if(cpu_tasks[i].pid == pid) return(i);
  84         }
  85         return(-1);
  86 }
  87
  88 void free_stack(unsigned long stack, int order)
  89 {
  90         free_pages(stack, order);
  91 }
  92
  93 unsigned long alloc_stack(int order, int atomic)
  94 {
  95         unsigned long page;
  96         int flags = GFP_KERNEL;
  97
  98         if(atomic) flags |= GFP_ATOMIC;
  99         page = __get_free_pages(flags, order);
 100         if(page == 0)
 101                 return(0);
 102         stack_protections(page);
 103         return(page);
 104 }
 105
 106 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 107 {
 108         int pid;
 109
 110         current->thread.request.u.thread.proc = fn;
 111         current->thread.request.u.thread.arg = arg;
 112         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, NULL, 0, NULL,
 113                       NULL);
 114         if(pid < 0)
 115                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 116         return(pid);
 117 }
 118
 119 void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 120                struct task_struct *tsk)
 121 {
 122         int cpu = smp_processor_id();
 123
 124         if (prev != next)
 125                 cpu_clear(cpu, prev->cpu_vm_mask);
 126         cpu_set(cpu, next->cpu_vm_mask);
 127 }
 128
 129 void set_current(void *t)
 130 {
 131         struct task_struct *task = t;
 132
 133         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 134                 { external_pid(task), task });
 135 }
 136
 137 void *_switch_to(void *prev, void *next, void *last)
 138 {
 139         return(CHOOSE_MODE(switch_to_tt(prev, next),
 140                            switch_to_skas(prev, next)));
 141 }
 142
 143 void interrupt_end(void)
 144 {
 145         if(need_resched()) schedule();
 146         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 147 }
 148
 149 void release_thread(struct task_struct *task)
 150 {
 151         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 152 }
 153
 154 void exit_thread(void)
 155 {
 156         CHOOSE_MODE(exit_thread_tt(), exit_thread_skas());
 157         unprotect_stack((unsigned long) current_thread);
 158 }
 159
 160 void *get_current(void)
 161 {
 162         return(current);
 163 }
 164
 165 void prepare_to_copy(struct task_struct *tsk)
 166 {
 167 }
 168
 169 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 170                 unsigned long stack_top, struct task_struct * p,
 171                 struct pt_regs *regs)
 172 {
 173         p->thread = (struct thread_struct) INIT_THREAD;
 174         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 175                                 clone_flags, sp, stack_top, p, regs));
 176 }
 177
 178 void initial_thread_cb(void (*proc)(void *), void *arg)
 179 {
 180         int save_kmalloc_ok = kmalloc_ok;
 181
 182         kmalloc_ok = 0;
 183         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 184                          arg);
 185         kmalloc_ok = save_kmalloc_ok;
 186 }
 187
 188 unsigned long stack_sp(unsigned long page)
 189 {
 190         return(page + PAGE_SIZE - sizeof(void *));
 191 }
 192
 193 int current_pid(void)
 194 {
 195         return(current->pid);
 196 }
 197
 198 void default_idle(void)
 199 {
 200         uml_idle_timer();
 201
 202         atomic_inc(&init_mm.mm_count);
 203         current->mm = &init_mm;
 204         current->active_mm = &init_mm;
 205
 206         while(1){
 207                 /* endless idle loop with no priority at all */
 208                 SET_PRI(current);
 209
 210                 /*
 211                  * although we are an idle CPU, we do not want to
 212                  * get into the scheduler unnecessarily.
 213                  */
 214                 if(need_resched())
 215                         schedule();
 216
 217                 idle_sleep(10);
 218         }
 219 }
 220
 221 void cpu_idle(void)
 222 {
 223         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 224 }
 225
 226 int page_size(void)
 227 {
 228         return(PAGE_SIZE);
 229 }
 230
 231 unsigned long page_mask(void)
 232 {
 233         return(PAGE_MASK);
 234 }
 235
 236 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 237                       pte_t *pte_out)
 238 {
 239         pgd_t *pgd;
 240         pud_t *pud;
 241         pmd_t *pmd;
 242         pte_t *pte;
 243
 244         if(task->mm == NULL)
 245                 return(ERR_PTR(-EINVAL));
 246         pgd = pgd_offset(task->mm, addr);
 247         if(!pgd_present(*pgd))
 248                 return(ERR_PTR(-EINVAL));
 249
 250         pud = pud_offset(pgd, addr);
 251         if(!pud_present(*pud))
 252                 return(ERR_PTR(-EINVAL));
 253
 254         pmd = pmd_offset(pud, addr);
 255         if(!pmd_present(*pmd))
 256                 return(ERR_PTR(-EINVAL));
 257
 258         pte = pte_offset_kernel(pmd, addr);
 259         if(!pte_present(*pte))
 260                 return(ERR_PTR(-EINVAL));
 261
 262         if(pte_out != NULL)
 263                 *pte_out = *pte;
 264         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 265 }
 266
 267 char *current_cmd(void)
 268 {
 269 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 270         return("(Unknown)");
 271 #else
 272         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 273         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 274 #endif
 275 }
 276
 277 void force_sigbus(void)
 278 {
 279         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 280                current->pid);
 281         lock_kernel();
 282         sigaddset(&current->pending.signal, SIGBUS);
 283         recalc_sigpending();
 284         current->flags |= PF_SIGNALED;
 285         do_exit(SIGBUS | 0x80);
 286 }
 287
 288 void dump_thread(struct pt_regs *regs, struct user *u)
 289 {
 290 }
 291
 292 void enable_hlt(void)
 293 {
 294         panic("enable_hlt");
 295 }
 296
 297 EXPORT_SYMBOL(enable_hlt);
 298
 299 void disable_hlt(void)
 300 {
 301         panic("disable_hlt");
 302 }
 303
 304 EXPORT_SYMBOL(disable_hlt);
 305
 306 void *um_kmalloc(int size)
 307 {
 308         return(kmalloc(size, GFP_KERNEL));
 309 }
 310
 311 void *um_kmalloc_atomic(int size)
 312 {
 313         return(kmalloc(size, GFP_ATOMIC));
 314 }
 315
 316 void *um_vmalloc(int size)
 317 {
 318         return(vmalloc(size));
 319 }
 320
 321 unsigned long get_fault_addr(void)
 322 {
 323         return((unsigned long) current->thread.fault_addr);
 324 }
 325
 326 EXPORT_SYMBOL(get_fault_addr);
 327
 328 void not_implemented(void)
 329 {
 330         printk(KERN_DEBUG "Something isn't implemented in here\n");
 331 }
 332
 333 EXPORT_SYMBOL(not_implemented);
 334
 335 int user_context(unsigned long sp)
 336 {
 337         unsigned long stack;
 338
 339         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 340         return(stack != (unsigned long) current_thread);
 341 }
 342
 343 extern void remove_umid_dir(void);
 344
 345 __uml_exitcall(remove_umid_dir);
 346
 347 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 348
 349 void do_uml_exitcalls(void)
 350 {
 351         exitcall_t *call;
 352
 353         call = &__uml_exitcall_end;
 354         while (--call >= &__uml_exitcall_begin)
 355                 (*call)();
 356 }
 357
 358 char *uml_strdup(char *string)
 359 {
 360         char *new;
 361
 362         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
 363         if(new == NULL) return(NULL);
 364         strcpy(new, string);
 365         return(new);
 366 }
 367
 368 void *get_init_task(void)
 369 {
 370         return(&init_thread_union.thread_info.task);
 371 }
 372
 373 int copy_to_user_proc(void __user *to, void *from, int size)
 374 {
 375         return(copy_to_user(to, from, size));
 376 }
 377
 378 int copy_from_user_proc(void *to, void __user *from, int size)
 379 {
 380         return(copy_from_user(to, from, size));
 381 }
 382
 383 int clear_user_proc(void __user *buf, int size)
 384 {
 385         return(clear_user(buf, size));
 386 }
 387
 388 int strlen_user_proc(char __user *str)
 389 {
 390         return(strlen_user(str));
 391 }
 392
 393 int smp_sigio_handler(void)
 394 {
 395 #ifdef CONFIG_SMP
 396         int cpu = current_thread->cpu;
 397         IPI_handler(cpu);
 398         if(cpu != 0)
 399                 return(1);
 400 #endif
 401         return(0);
 402 }
 403
 404 int um_in_interrupt(void)
 405 {
 406         return(in_interrupt());
 407 }
 408
 409 int cpu(void)
 410 {
 411         return(current_thread->cpu);
 412 }
 413
 414 static atomic_t using_sysemu = ATOMIC_INIT(0);
 415 int sysemu_supported;
 416
 417 void set_using_sysemu(int value)
 418 {
 419         if (value > sysemu_supported)
 420                 return;
 421         atomic_set(&using_sysemu, value);
 422 }
 423
 424 int get_using_sysemu(void)
 425 {
 426         return atomic_read(&using_sysemu);
 427 }
 428
 429 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 430 {
 431         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 432                 *eof = 1;
 433
 434         return strlen(buf);
 435 }
 436
 437 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 438 {
 439         char tmp[2];
 440
 441         if (copy_from_user(tmp, buf, 1))
 442                 return -EFAULT;
 443
 444         if (tmp[0] >= '0' && tmp[0] <= '2')
 445                 set_using_sysemu(tmp[0] - '0');
 446         return count; /*We use the first char, but pretend to write everything*/
 447 }
 448
 449 int __init make_proc_sysemu(void)
 450 {
 451         struct proc_dir_entry *ent;
 452         if (!sysemu_supported)
 453                 return 0;
 454
 455         ent = create_proc_entry("sysemu", 0600, &proc_root);
 456
 457         if (ent == NULL)
 458         {
 459                 printk("Failed to register /proc/sysemu\n");
 460                 return(0);
 461         }
 462
 463         ent->read_proc  = proc_read_sysemu;
 464         ent->write_proc = proc_write_sysemu;
 465
 466         return 0;
 467 }
 468
 469 late_initcall(make_proc_sysemu);
 470
 471 int singlestepping(void * t)
 472 {
 473         struct task_struct *task = t ? t : current;
 474
 475         if ( ! (task->ptrace & PT_DTRACE) )
 476                 return(0);
 477
 478         if (task->thread.singlestep_syscall)
 479                 return(1);
 480
 481         return 2;
 482 }
 483
 484 /*
 485  * Overrides for Emacs so that we follow Linus's tabbing style.
 486  * Emacs will notice this stuff at the end of the file and automatically
 487  * adjust the settings for this buffer only.  This must remain at the end
 488  * of the file.
 489  * ---------------------------------------------------------------------------
 490  * Local variables:
 491  * c-file-style: "linux"
 492  * End:
 493  */