arch/um/kernel/process_kern.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/config.h"
   7 #include "linux/kernel.h"
   8 #include "linux/sched.h"
   9 #include "linux/interrupt.h"
  10 #include "linux/mm.h"
  11 #include "linux/slab.h"
  12 #include "linux/utsname.h"
  13 #include "linux/fs.h"
  14 #include "linux/utime.h"
  15 #include "linux/smp_lock.h"
  16 #include "linux/module.h"
  17 #include "linux/init.h"
  18 #include "linux/capability.h"
  19 #include "linux/vmalloc.h"
  20 #include "linux/spinlock.h"
  21 #include "asm/unistd.h"
  22 #include "asm/mman.h"
  23 #include "asm/segment.h"
  24 #include "asm/stat.h"
  25 #include "asm/pgtable.h"
  26 #include "asm/processor.h"
  27 #include "asm/tlbflush.h"
  28 #include "asm/uaccess.h"
  29 #include "asm/user.h"
  30 #include "user_util.h"
  31 #include "kern_util.h"
  32 #include "kern.h"
  33 #include "signal_kern.h"
  34 #include "signal_user.h"
  35 #include "init.h"
  36 #include "irq_user.h"
  37 #include "mem_user.h"
  38 #include "time_user.h"
  39 #include "tlb.h"
  40 #include "frame_kern.h"
  41 #include "sigcontext.h"
  42 #include "2_5compat.h"
  43 #include "os.h"
  44 #include "mode.h"
  45 #include "mode_kern.h"
  46 #include "choose-mode.h"
  47
  48 /* This is a per-cpu array.  A processor only modifies its entry and it only
  49  * cares about its entry, so it's OK if another processor is modifying its
  50  * entry.
  51  */
  52 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
  53
  54 struct task_struct *get_task(int pid, int require)
  55 {
  56         struct task_struct *ret;
  57
  58         read_lock(&tasklist_lock);
  59         ret = find_task_by_pid(pid);
  60         read_unlock(&tasklist_lock);
  61
  62         if(require && (ret == NULL)) panic("get_task couldn't find a task\n");
  63         return(ret);
  64 }
  65
  66 int external_pid(void *t)
  67 {
  68         struct task_struct *task = t ? t : current;
  69
  70         return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
  71 }
  72
  73 int pid_to_processor_id(int pid)
  74 {
  75         int i;
  76
  77         for(i = 0; i < ncpus; i++){
  78                 if(cpu_tasks[i].pid == pid) return(i);
  79         }
  80         return(-1);
  81 }
  82
  83 void free_stack(unsigned long stack, int order)
  84 {
  85         free_pages(stack, order);
  86 }
  87
  88 unsigned long alloc_stack(int order, int atomic)
  89 {
  90         unsigned long page;
  91         int flags = GFP_KERNEL;
  92
  93         if(atomic) flags |= GFP_ATOMIC;
  94         page = __get_free_pages(flags, order);
  95         if(page == 0)
  96                 return(0);
  97         stack_protections(page);
  98         return(page);
  99 }
 100
 101 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 102 {
 103         int pid;
 104
 105         current->thread.request.u.thread.proc = fn;
 106         current->thread.request.u.thread.arg = arg;
 107         pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0, NULL, 0, NULL,
 108                       NULL);
 109         if(pid < 0)
 110                 panic("do_fork failed in kernel_thread, errno = %d", pid);
 111         return(pid);
 112 }
 113
 114 void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 115                struct task_struct *tsk)
 116 {
 117         unsigned cpu = smp_processor_id();
 118         if (prev != next)
 119                 clear_bit(cpu, &prev->cpu_vm_mask);
 120         set_bit(cpu, &next->cpu_vm_mask);
 121 }
 122
 123 void set_current(void *t)
 124 {
 125         struct task_struct *task = t;
 126
 127         cpu_tasks[task->thread_info->cpu] = ((struct cpu_task)
 128                 { external_pid(task), task });
 129 }
 130
 131 void *_switch_to(void *prev, void *next, void *last)
 132 {
 133         return(CHOOSE_MODE(switch_to_tt(prev, next),
 134                            switch_to_skas(prev, next)));
 135 }
 136
 137 void interrupt_end(void)
 138 {
 139         if(need_resched()) schedule();
 140         if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal(0);
 141 }
 142
 143 void release_thread(struct task_struct *task)
 144 {
 145         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 146 }
 147
 148 void exit_thread(void)
 149 {
 150         CHOOSE_MODE(exit_thread_tt(), exit_thread_skas());
 151         unprotect_stack((unsigned long) current_thread);
 152 }
 153
 154 void *get_current(void)
 155 {
 156         return(current);
 157 }
 158
 159 void prepare_to_copy(struct task_struct *tsk)
 160 {
 161 }
 162
 163 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 164                 unsigned long stack_top, struct task_struct * p,
 165                 struct pt_regs *regs)
 166 {
 167         p->thread = (struct thread_struct) INIT_THREAD;
 168         return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
 169                                 clone_flags, sp, stack_top, p, regs));
 170 }
 171
 172 void initial_thread_cb(void (*proc)(void *), void *arg)
 173 {
 174         int save_kmalloc_ok = kmalloc_ok;
 175
 176         kmalloc_ok = 0;
 177         CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 178                          arg);
 179         kmalloc_ok = save_kmalloc_ok;
 180 }
 181
 182 unsigned long stack_sp(unsigned long page)
 183 {
 184         return(page + PAGE_SIZE - sizeof(void *));
 185 }
 186
 187 int current_pid(void)
 188 {
 189         return(current->pid);
 190 }
 191
 192 void default_idle(void)
 193 {
 194         uml_idle_timer();
 195
 196         atomic_inc(&init_mm.mm_count);
 197         current->mm = &init_mm;
 198         current->active_mm = &init_mm;
 199
 200         while(1){
 201                 /* endless idle loop with no priority at all */
 202                 SET_PRI(current);
 203
 204                 /*
 205                  * although we are an idle CPU, we do not want to
 206                  * get into the scheduler unnecessarily.
 207                  */
 208                 irq_stat[smp_processor_id()].idle_timestamp = jiffies;
 209                 if(need_resched())
 210                         schedule();
 211
 212                 idle_sleep(10);
 213         }
 214 }
 215
 216 void cpu_idle(void)
 217 {
 218         CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 219 }
 220
 221 int page_size(void)
 222 {
 223         return(PAGE_SIZE);
 224 }
 225
 226 int page_mask(void)
 227 {
 228         return(PAGE_MASK);
 229 }
 230
 231 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 232                       pte_t *pte_out)
 233 {
 234         pgd_t *pgd;
 235         pmd_t *pmd;
 236         pte_t *pte;
 237
 238         if(task->mm == NULL)
 239                 return(ERR_PTR(-EINVAL));
 240         pgd = pgd_offset(task->mm, addr);
 241         pmd = pmd_offset(pgd, addr);
 242         if(!pmd_present(*pmd))
 243                 return(ERR_PTR(-EINVAL));
 244         pte = pte_offset_kernel(pmd, addr);
 245         if(!pte_present(*pte))
 246                 return(ERR_PTR(-EINVAL));
 247         if(pte_out != NULL)
 248                 *pte_out = *pte;
 249         return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 250 }
 251
 252 char *current_cmd(void)
 253 {
 254 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 255         return("(Unknown)");
 256 #else
 257         void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
 258         return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 259 #endif
 260 }
 261
 262 void force_sigbus(void)
 263 {
 264         printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 265                current->pid);
 266         lock_kernel();
 267         sigaddset(&current->pending.signal, SIGBUS);
 268         recalc_sigpending();
 269         current->flags |= PF_SIGNALED;
 270         do_exit(SIGBUS | 0x80);
 271 }
 272
 273 void dump_thread(struct pt_regs *regs, struct user *u)
 274 {
 275 }
 276
 277 void enable_hlt(void)
 278 {
 279         panic("enable_hlt");
 280 }
 281
 282 EXPORT_SYMBOL(enable_hlt);
 283
 284 void disable_hlt(void)
 285 {
 286         panic("disable_hlt");
 287 }
 288
 289 EXPORT_SYMBOL(disable_hlt);
 290
 291 extern int signal_frame_size;
 292
 293 void *um_kmalloc(int size)
 294 {
 295         return(kmalloc(size, GFP_KERNEL));
 296 }
 297
 298 void *um_kmalloc_atomic(int size)
 299 {
 300         return(kmalloc(size, GFP_ATOMIC));
 301 }
 302
 303 void *um_vmalloc(int size)
 304 {
 305         return(vmalloc(size));
 306 }
 307
 308 unsigned long get_fault_addr(void)
 309 {
 310         return((unsigned long) current->thread.fault_addr);
 311 }
 312
 313 EXPORT_SYMBOL(get_fault_addr);
 314
 315 void not_implemented(void)
 316 {
 317         printk(KERN_DEBUG "Something isn't implemented in here\n");
 318 }
 319
 320 EXPORT_SYMBOL(not_implemented);
 321
 322 int user_context(unsigned long sp)
 323 {
 324         unsigned long stack;
 325
 326         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
 327         return(stack != (unsigned long) current_thread);
 328 }
 329
 330 extern void remove_umid_dir(void);
 331
 332 __uml_exitcall(remove_umid_dir);
 333
 334 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 335
 336 void do_uml_exitcalls(void)
 337 {
 338         exitcall_t *call;
 339
 340         call = &__uml_exitcall_end;
 341         while (--call >= &__uml_exitcall_begin)
 342                 (*call)();
 343 }
 344
 345 char *uml_strdup(char *string)
 346 {
 347         char *new;
 348
 349         new = kmalloc(strlen(string) + 1, GFP_KERNEL);
 350         if(new == NULL) return(NULL);
 351         strcpy(new, string);
 352         return(new);
 353 }
 354
 355 void *get_init_task(void)
 356 {
 357         return(&init_thread_union.thread_info.task);
 358 }
 359
 360 int copy_to_user_proc(void *to, void *from, int size)
 361 {
 362         return(copy_to_user(to, from, size));
 363 }
 364
 365 int copy_from_user_proc(void *to, void *from, int size)
 366 {
 367         return(copy_from_user(to, from, size));
 368 }
 369
 370 int clear_user_proc(void *buf, int size)
 371 {
 372         return(clear_user(buf, size));
 373 }
 374
 375 int strlen_user_proc(char *str)
 376 {
 377         return(strlen_user(str));
 378 }
 379
 380 int smp_sigio_handler(void)
 381 {
 382 #ifdef CONFIG_SMP
 383         int cpu = current_thread->cpu;
 384         IPI_handler(cpu);
 385         if(cpu != 0)
 386                 return(1);
 387 #endif
 388         return(0);
 389 }
 390
 391 int um_in_interrupt(void)
 392 {
 393         return(in_interrupt());
 394 }
 395
 396 int cpu(void)
 397 {
 398         return(current_thread->cpu);
 399 }
 400
 401 /*
 402  * Overrides for Emacs so that we follow Linus's tabbing style.
 403  * Emacs will notice this stuff at the end of the file and automatically
 404  * adjust the settings for this buffer only.  This must remain at the end
 405  * of the file.
 406  * ---------------------------------------------------------------------------
 407  * Local variables:
 408  * c-file-style: "linux"
 409  * End:
 410  */