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