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