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/vs_cvirt.h"
  23 #include "linux/proc_fs.h"
  24 #include "linux/ptrace.h"
  25 #include "linux/vs_cvirt.h"
  26
  27 #include "asm/unistd.h"
  28 #include "asm/mman.h"
  29 #include "asm/segment.h"
  30 #include "asm/stat.h"
  31 #include "asm/pgtable.h"
  32 #include "asm/processor.h"
  33 #include "asm/tlbflush.h"
  34 #include "asm/uaccess.h"
  35 #include "asm/user.h"
  36 #include "user_util.h"
  37 #include "kern_util.h"
  38 #include "kern.h"
  39 #include "signal_kern.h"
  40 #include "signal_user.h"
  41 #include "init.h"
  42 #include "irq_user.h"
  43 #include "mem_user.h"
  44 #include "time_user.h"
  45 #include "tlb.h"
  46 #include "frame_kern.h"
  47 #include "sigcontext.h"
  48 #include "2_5compat.h"
  49 #include "os.h"
  50 #include "mode.h"
  51 #include "mode_kern.h"
  52 #include "choose-mode.h"
  53
  54 /* This is a per-cpu array.  A processor only modifies its entry and it only
  55  * cares about its entry, so it's OK if another processor is modifying its
  56  * entry.
  57  */
  58 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  59
  60 struct task_struct *get_task(int pid, int require)
  61 {
  62         struct task_struct *ret;
  63
  64         read_lock(&tasklist_lock);
  65         ret = find_task_by_pid(pid);
  66         read_unlock(&tasklist_lock);
  67
  68         if(require && (ret == NULL)) panic("get_task couldn't find a task\n");
  69         return(ret);
  70 }
  71
  72 int external_pid(void *t)
  73 {
  74         struct task_struct *task = t ? t : current;
  75
  76         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  77 }
  78
  79 int pid_to_processor_id(int pid)
  80 {
  81         int i;
  82
  83         for(i = 0; i < ncpus; i++){
  84                 if(cpu_tasks[i].pid == pid) return(i);
  85         }
  86         return(-1);
  87 }
  88
  89 void free_stack(unsigned long stack, int order)
  90 {
  91         free_pages(stack, order);
  92 }
  93
  94 unsigned long alloc_stack(int order, int atomic)
  95 {
  96         unsigned long page;
  97         int flags = GFP_KERNEL;
  98
  99         if(atomic) flags |= GFP_ATOMIC;
 100         page = __get_free_pages(flags, order);
 101         if(page == 0)
 102                 return(0);
 103         stack_protections(page);
 104         return(page);
 105 }
 106
 107 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 108 {
 109         int pid;
 110
 111         current->thread.request.u.thread.proc = fn;
 112         current->thread.request.u.thread.arg = arg;
 113         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, NULL, 0, NULL,
 114                       NULL);
 115         if(pid < 0)
 116                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 117         return(pid);
 118 }
 119
 120 void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 121                struct task_struct *tsk)
 122 {
 123         int cpu = smp_processor_id();
 124
 125         if (prev != next)
 126                 cpu_clear(cpu, prev->cpu_vm_mask);
 127         cpu_set(cpu, next->cpu_vm_mask);
 128 }
 129
 130 void set_current(void *t)
 131 {
 132         struct task_struct *task = t;
 133
 134         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 135                 { external_pid(task), task });
 136 }
 137
 138 void *_switch_to(void *prev, void *next, void *last)
 139 {
 140         return(CHOOSE_MODE(switch_to_tt(prev, next),
 141                            switch_to_skas(prev, next)));
 142 }
 143
 144 void interrupt_end(void)
 145 {
 146         if(need_resched()) schedule();
 147         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
 148 }
 149
 150 void release_thread(struct task_struct *task)
 151 {
 152         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 153 }
 154
 155 void exit_thread(void)
 156 {
 157         CHOOSE_MODE(exit_thread_tt(), exit_thread_skas());
 158         unprotect_stack((unsigned long) current_thread);
 159 }
 160
 161 void *get_current(void)
 162 {
 163         return(current);
 164 }
 165
 166 void prepare_to_copy(struct task_struct *tsk)
 167 {
 168 }
 169
 170 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 171                 unsigned long stack_top, struct task_struct * p,
 172                 struct pt_regs *regs)
 173 {
 174         p->thread = (struct thread_struct) INIT_THREAD;
 175         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 176                                 clone_flags, sp, stack_top, p, regs));
 177 }
 178
 179 void initial_thread_cb(void (*proc)(void *), void *arg)
 180 {
 181         int save_kmalloc_ok = kmalloc_ok;
 182
 183         kmalloc_ok = 0;
 184         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 185                          arg);
 186         kmalloc_ok = save_kmalloc_ok;
 187 }
 188
 189 unsigned long stack_sp(unsigned long page)
 190 {
 191         return(page + PAGE_SIZE - sizeof(void *));
 192 }
 193
 194 int current_pid(void)
 195 {
 196         return(current->pid);
 197 }
 198
 199 void default_idle(void)
 200 {
 201         uml_idle_timer();
 202
 203         atomic_inc(&init_mm.mm_count);
 204         current->mm = &init_mm;
 205         current->active_mm = &init_mm;
 206
 207         while(1){
 208                 /* endless idle loop with no priority at all */
 209                 SET_PRI(current);
 210
 211                 /*
 212                  * although we are an idle CPU, we do not want to
 213                  * get into the scheduler unnecessarily.
 214                  */
 215                 if(need_resched())
 216                         schedule();
 217
 218                 idle_sleep(10);
 219         }
 220 }
 221
 222 void cpu_idle(void)
 223 {
 224         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 225 }
 226
 227 int page_size(void)
 228 {
 229         return(PAGE_SIZE);
 230 }
 231
 232 unsigned long page_mask(void)
 233 {
 234         return(PAGE_MASK);
 235 }
 236
 237 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 238                       pte_t *pte_out)
 239 {
 240         pgd_t *pgd;
 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         pmd = pmd_offset(pgd, addr);
 248         if(!pmd_present(*pmd))
 249                 return(ERR_PTR(-EINVAL));
 250         pte = pte_offset_kernel(pmd, addr);
 251         if(!pte_present(*pte))
 252                 return(ERR_PTR(-EINVAL));
 253         if(pte_out != NULL)
 254                 *pte_out = *pte;
 255         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 256 }
 257
 258 char *current_cmd(void)
 259 {
 260 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 261         return("(Unknown)");
 262 #else
 263         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 264         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 265 #endif
 266 }
 267
 268 void force_sigbus(void)
 269 {
 270         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 271                current->pid);
 272         lock_kernel();
 273         sigaddset(&current->pending.signal, SIGBUS);
 274         recalc_sigpending();
 275         current->flags |= PF_SIGNALED;
 276         do_exit(SIGBUS | 0x80);
 277 }
 278
 279 void dump_thread(struct pt_regs *regs, struct user *u)
 280 {
 281 }
 282
 283 void enable_hlt(void)
 284 {
 285         panic("enable_hlt");
 286 }
 287
 288 EXPORT_SYMBOL(enable_hlt);
 289
 290 void disable_hlt(void)
 291 {
 292         panic("disable_hlt");
 293 }
 294
 295 EXPORT_SYMBOL(disable_hlt);
 296
 297 extern int signal_frame_size;
 298
 299 void *um_kmalloc(int size)
 300 {
 301         return(kmalloc(size, GFP_KERNEL));
 302 }
 303
 304 void *um_kmalloc_atomic(int size)
 305 {
 306         return(kmalloc(size, GFP_ATOMIC));
 307 }
 308
 309 void *um_vmalloc(int size)
 310 {
 311         return(vmalloc(size));
 312 }
 313
 314 unsigned long get_fault_addr(void)
 315 {
 316         return((unsigned long) current->thread.fault_addr);
 317 }
 318
 319 EXPORT_SYMBOL(get_fault_addr);
 320
 321 void not_implemented(void)
 322 {
 323         printk(KERN_DEBUG "Something isn't implemented in here\n");
 324 }
 325
 326 EXPORT_SYMBOL(not_implemented);
 327
 328 int user_context(unsigned long sp)
 329 {
 330         unsigned long stack;
 331
 332         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 333         return(stack != (unsigned long) current_thread);
 334 }
 335
 336 extern void remove_umid_dir(void);
 337
 338 __uml_exitcall(remove_umid_dir);
 339
 340 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 341
 342 void do_uml_exitcalls(void)
 343 {
 344         exitcall_t *call;
 345
 346         call = &__uml_exitcall_end;
 347         while (--call >= &__uml_exitcall_begin)
 348                 (*call)();
 349 }
 350
 351 char *uml_strdup(char *string)
 352 {
 353         char *new;
 354
 355         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
 356         if(new == NULL) return(NULL);
 357         strcpy(new, string);
 358         return(new);
 359 }
 360
 361 void *get_init_task(void)
 362 {
 363         return(&init_thread_union.thread_info.task);
 364 }
 365
 366 int copy_to_user_proc(void *to, void *from, int size)
 367 {
 368         return(copy_to_user(to, from, size));
 369 }
 370
 371 int copy_from_user_proc(void *to, void *from, int size)
 372 {
 373         return(copy_from_user(to, from, size));
 374 }
 375
 376 int clear_user_proc(void *buf, int size)
 377 {
 378         return(clear_user(buf, size));
 379 }
 380
 381 int strlen_user_proc(char *str)
 382 {
 383         return(strlen_user(str));
 384 }
 385
 386 int smp_sigio_handler(void)
 387 {
 388 #ifdef CONFIG_SMP
 389         int cpu = current_thread->cpu;
 390         IPI_handler(cpu);
 391         if(cpu != 0)
 392                 return(1);
 393 #endif
 394         return(0);
 395 }
 396
 397 int um_in_interrupt(void)
 398 {
 399         return(in_interrupt());
 400 }
 401
 402 int cpu(void)
 403 {
 404         return(current_thread->cpu);
 405 }
 406
 407 static atomic_t using_sysemu = ATOMIC_INIT(0);
 408 int sysemu_supported;
 409
 410 void set_using_sysemu(int value)
 411 {
 412         atomic_set(&using_sysemu, sysemu_supported && value);
 413 }
 414
 415 int get_using_sysemu(void)
 416 {
 417         return atomic_read(&using_sysemu);
 418 }
 419
 420 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 421 {
 422         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
 423                 *eof = 1;
 424
 425         return strlen(buf);
 426 }
 427
 428 static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
 429 {
 430         char tmp[2];
 431
 432         if (copy_from_user(tmp, buf, 1))
 433                 return -EFAULT;
 434
 435         if (tmp[0] == '0' || tmp[0] == '1')
 436                 set_using_sysemu(tmp[0] - '0');
 437         return count; /*We use the first char, but pretend to write everything*/
 438 }
 439
 440 int __init make_proc_sysemu(void)
 441 {
 442         struct proc_dir_entry *ent;
 443         if (!sysemu_supported)
 444                 return 0;
 445
 446         ent = create_proc_entry("sysemu", 0600, &proc_root);
 447
 448         if (ent == NULL)
 449         {
 450                 printk("Failed to register /proc/sysemu\n");
 451                 return(0);
 452         }
 453
 454         ent->read_proc  = proc_read_sysemu;
 455         ent->write_proc = proc_write_sysemu;
 456
 457         return 0;
 458 }
 459
 460 late_initcall(make_proc_sysemu);
 461
 462 int singlestepping(void * t)
 463 {
 464         struct task_struct *task = t ? t : current;
 465
 466         if ( ! (task->ptrace & PT_DTRACE) )
 467                 return(0);
 468
 469         if (task->thread.singlestep_syscall)
 470                 return(0);
 471
 472         return 1;
 473 }
 474
 475 /*
 476  * Overrides for Emacs so that we follow Linus's tabbing style.
 477  * Emacs will notice this stuff at the end of the file and automatically
 478  * adjust the settings for this buffer only.  This must remain at the end
 479  * of the file.
 480  * ---------------------------------------------------------------------------
 481  * Local variables:
 482  * c-file-style: "linux"
 483  * End:
 484  */