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