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