git.oblomov.eu Git - linux-2.6/blob - arch/um/kernel/um_arch.c

   1 /*
   2  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/kernel.h"
   7 #include "linux/sched.h"
   8 #include "linux/notifier.h"
   9 #include "linux/mm.h"
  10 #include "linux/types.h"
  11 #include "linux/tty.h"
  12 #include "linux/init.h"
  13 #include "linux/bootmem.h"
  14 #include "linux/spinlock.h"
  15 #include "linux/utsname.h"
  16 #include "linux/sysrq.h"
  17 #include "linux/seq_file.h"
  18 #include "linux/delay.h"
  19 #include "linux/module.h"
  20 #include "linux/utsname.h"
  21 #include "asm/page.h"
  22 #include "asm/pgtable.h"
  23 #include "asm/ptrace.h"
  24 #include "asm/elf.h"
  25 #include "asm/user.h"
  26 #include "asm/setup.h"
  27 #include "ubd_user.h"
  28 #include "asm/current.h"
  29 #include "kern_util.h"
  30 #include "as-layout.h"
  31 #include "arch.h"
  32 #include "kern.h"
  33 #include "mem_user.h"
  34 #include "mem.h"
  35 #include "initrd.h"
  36 #include "init.h"
  37 #include "os.h"
  38 #include "skas.h"
  39
  40 #define DEFAULT_COMMAND_LINE "root=98:0"
  41
  42 /* Changed in add_arg and setup_arch, which run before SMP is started */
  43 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
  44
  45 static void __init add_arg(char *arg)
  46 {
  47         if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
  48                 printf("add_arg: Too many command line arguments!\n");
  49                 exit(1);
  50         }
  51         if(strlen(command_line) > 0)
  52                 strcat(command_line, " ");
  53         strcat(command_line, arg);
  54 }
  55
  56 /*
  57  * These fields are initialized at boot time and not changed.
  58  * XXX This structure is used only in the non-SMP case.  Maybe this
  59  * should be moved to smp.c.
  60  */
  61 struct cpuinfo_um boot_cpu_data = {
  62         .loops_per_jiffy        = 0,
  63         .ipi_pipe               = { -1, -1 }
  64 };
  65
  66 unsigned long thread_saved_pc(struct task_struct *task)
  67 {
  68         /* FIXME: Need to look up userspace_pid by cpu */
  69         return os_process_pc(userspace_pid[0]);
  70 }
  71
  72 /* Changed in setup_arch, which is called in early boot */
  73 static char host_info[(__NEW_UTS_LEN + 1) * 5];
  74
  75 static int show_cpuinfo(struct seq_file *m, void *v)
  76 {
  77         int index = 0;
  78
  79 #ifdef CONFIG_SMP
  80         index = (struct cpuinfo_um *) v - cpu_data;
  81         if (!cpu_online(index))
  82                 return 0;
  83 #endif
  84
  85         seq_printf(m, "processor\t: %d\n", index);
  86         seq_printf(m, "vendor_id\t: User Mode Linux\n");
  87         seq_printf(m, "model name\t: UML\n");
  88         seq_printf(m, "mode\t\t: skas\n");
  89         seq_printf(m, "host\t\t: %s\n", host_info);
  90         seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
  91                    loops_per_jiffy/(500000/HZ),
  92                    (loops_per_jiffy/(5000/HZ)) % 100);
  93
  94         return 0;
  95 }
  96
  97 static void *c_start(struct seq_file *m, loff_t *pos)
  98 {
  99         return *pos < NR_CPUS ? cpu_data + *pos : NULL;
 100 }
 101
 102 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 103 {
 104         ++*pos;
 105         return c_start(m, pos);
 106 }
 107
 108 static void c_stop(struct seq_file *m, void *v)
 109 {
 110 }
 111
 112 const struct seq_operations cpuinfo_op = {
 113         .start  = c_start,
 114         .next   = c_next,
 115         .stop   = c_stop,
 116         .show   = show_cpuinfo,
 117 };
 118
 119 /* Set in linux_main */
 120 unsigned long host_task_size;
 121 unsigned long task_size;
 122 unsigned long uml_physmem;
 123 unsigned long uml_reserved; /* Also modified in mem_init */
 124 unsigned long start_vm;
 125 unsigned long end_vm;
 126
 127 /* Set in uml_ncpus_setup */
 128 int ncpus = 1;
 129
 130 /* Set in early boot */
 131 static int have_root __initdata = 0;
 132
 133 /* Set in uml_mem_setup and modified in linux_main */
 134 long long physmem_size = 32 * 1024 * 1024;
 135
 136 static char *usage_string =
 137 "User Mode Linux v%s\n"
 138 "       available at http://user-mode-linux.sourceforge.net/\n\n";
 139
 140 static int __init uml_version_setup(char *line, int *add)
 141 {
 142         printf("%s\n", init_utsname()->release);
 143         exit(0);
 144
 145         return 0;
 146 }
 147
 148 __uml_setup("--version", uml_version_setup,
 149 "--version\n"
 150 "    Prints the version number of the kernel.\n\n"
 151 );
 152
 153 static int __init uml_root_setup(char *line, int *add)
 154 {
 155         have_root = 1;
 156         return 0;
 157 }
 158
 159 __uml_setup("root=", uml_root_setup,
 160 "root=<file containing the root fs>\n"
 161 "    This is actually used by the generic kernel in exactly the same\n"
 162 "    way as in any other kernel. If you configure a number of block\n"
 163 "    devices and want to boot off something other than ubd0, you \n"
 164 "    would use something like:\n"
 165 "        root=/dev/ubd5\n\n"
 166 );
 167
 168 static int __init no_skas_debug_setup(char *line, int *add)
 169 {
 170         printf("'debug' is not necessary to gdb UML in skas mode - run \n");
 171         printf("'gdb linux'");
 172
 173         return 0;
 174 }
 175
 176 __uml_setup("debug", no_skas_debug_setup,
 177 "debug\n"
 178 "    this flag is not needed to run gdb on UML in skas mode\n\n"
 179 );
 180
 181 #ifdef CONFIG_SMP
 182 static int __init uml_ncpus_setup(char *line, int *add)
 183 {
 184         if (!sscanf(line, "%d", &ncpus)) {
 185                 printf("Couldn't parse [%s]\n", line);
 186                 return -1;
 187         }
 188
 189         return 0;
 190 }
 191
 192 __uml_setup("ncpus=", uml_ncpus_setup,
 193 "ncpus=<# of desired CPUs>\n"
 194 "    This tells an SMP kernel how many virtual processors to start.\n\n"
 195 );
 196 #endif
 197
 198 static int __init Usage(char *line, int *add)
 199 {
 200         const char **p;
 201
 202         printf(usage_string, init_utsname()->release);
 203         p = &__uml_help_start;
 204         while (p < &__uml_help_end) {
 205                 printf("%s", *p);
 206                 p++;
 207         }
 208         exit(0);
 209         return 0;
 210 }
 211
 212 __uml_setup("--help", Usage,
 213 "--help\n"
 214 "    Prints this message.\n\n"
 215 );
 216
 217 static int __init uml_checksetup(char *line, int *add)
 218 {
 219         struct uml_param *p;
 220
 221         p = &__uml_setup_start;
 222         while(p < &__uml_setup_end) {
 223                 int n;
 224
 225                 n = strlen(p->str);
 226                 if(!strncmp(line, p->str, n)){
 227                         if (p->setup_func(line + n, add)) return 1;
 228                 }
 229                 p++;
 230         }
 231         return 0;
 232 }
 233
 234 static void __init uml_postsetup(void)
 235 {
 236         initcall_t *p;
 237
 238         p = &__uml_postsetup_start;
 239         while(p < &__uml_postsetup_end){
 240                 (*p)();
 241                 p++;
 242         }
 243         return;
 244 }
 245
 246 /* Set during early boot */
 247 unsigned long brk_start;
 248 unsigned long end_iomem;
 249 EXPORT_SYMBOL(end_iomem);
 250
 251 #define MIN_VMALLOC (32 * 1024 * 1024)
 252
 253 extern char __binary_start;
 254
 255 static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
 256 {
 257         /* Round up to the nearest 4M */
 258         unsigned long host_task_size = ROUND_4M((unsigned long)
 259                                                 &host_task_size);
 260
 261         if (!skas_needs_stub)
 262                 *task_size_out = host_task_size;
 263         else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
 264
 265         return host_task_size;
 266 }
 267
 268 int __init linux_main(int argc, char **argv)
 269 {
 270         unsigned long avail, diff;
 271         unsigned long virtmem_size, max_physmem;
 272         unsigned int i, add;
 273         char * mode;
 274
 275         for (i = 1; i < argc; i++){
 276                 if((i == 1) && (argv[i][0] == ' ')) continue;
 277                 add = 1;
 278                 uml_checksetup(argv[i], &add);
 279                 if (add)
 280                         add_arg(argv[i]);
 281         }
 282         if(have_root == 0)
 283                 add_arg(DEFAULT_COMMAND_LINE);
 284
 285         os_early_checks();
 286
 287         can_do_skas();
 288
 289         if (proc_mm && ptrace_faultinfo)
 290                 mode = "SKAS3";
 291         else
 292                 mode = "SKAS0";
 293
 294         printf("UML running in %s mode\n", mode);
 295
 296         host_task_size = set_task_sizes_skas(&task_size);
 297
 298         /*
 299          * Setting up handlers to 'sig_info' struct
 300          */
 301         os_fill_handlinfo(handlinfo_kern);
 302
 303         brk_start = (unsigned long) sbrk(0);
 304
 305         /* Increase physical memory size for exec-shield users
 306         so they actually get what they asked for. This should
 307         add zero for non-exec shield users */
 308
 309         diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 310         if(diff > 1024 * 1024){
 311                 printf("Adding %ld bytes to physical memory to account for "
 312                        "exec-shield gap\n", diff);
 313                 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 314         }
 315
 316         uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
 317
 318         /* Reserve up to 4M after the current brk */
 319         uml_reserved = ROUND_4M(brk_start) + (1 << 22);
 320
 321         setup_machinename(init_utsname()->machine);
 322
 323         highmem = 0;
 324         iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
 325         max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
 326
 327         /* Zones have to begin on a 1 << MAX_ORDER page boundary,
 328          * so this makes sure that's true for highmem
 329          */
 330         max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
 331         if(physmem_size + iomem_size > max_physmem){
 332                 highmem = physmem_size + iomem_size - max_physmem;
 333                 physmem_size -= highmem;
 334 #ifndef CONFIG_HIGHMEM
 335                 highmem = 0;
 336                 printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
 337                        "to %Lu bytes\n", physmem_size);
 338 #endif
 339         }
 340
 341         high_physmem = uml_physmem + physmem_size;
 342         end_iomem = high_physmem + iomem_size;
 343         high_memory = (void *) end_iomem;
 344
 345         start_vm = VMALLOC_START;
 346
 347         setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
 348         if(init_maps(physmem_size, iomem_size, highmem)){
 349                 printf("Failed to allocate mem_map for %Lu bytes of physical "
 350                        "memory and %Lu bytes of highmem\n", physmem_size,
 351                        highmem);
 352                 exit(1);
 353         }
 354
 355         virtmem_size = physmem_size;
 356         avail = get_kmem_end() - start_vm;
 357         if(physmem_size > avail) virtmem_size = avail;
 358         end_vm = start_vm + virtmem_size;
 359
 360         if(virtmem_size < physmem_size)
 361                 printf("Kernel virtual memory size shrunk to %lu bytes\n",
 362                        virtmem_size);
 363
 364         uml_postsetup();
 365
 366         stack_protections((unsigned long) &init_thread_info);
 367         os_flush_stdout();
 368
 369         return start_uml();
 370 }
 371
 372 extern int uml_exitcode;
 373
 374 static int panic_exit(struct notifier_block *self, unsigned long unused1,
 375                       void *unused2)
 376 {
 377         bust_spinlocks(1);
 378         show_regs(&(current->thread.regs));
 379         bust_spinlocks(0);
 380         uml_exitcode = 1;
 381         os_dump_core();
 382         return 0;
 383 }
 384
 385 static struct notifier_block panic_exit_notifier = {
 386         .notifier_call          = panic_exit,
 387         .next                   = NULL,
 388         .priority               = 0
 389 };
 390
 391 void __init setup_arch(char **cmdline_p)
 392 {
 393         atomic_notifier_chain_register(&panic_notifier_list,
 394                         &panic_exit_notifier);
 395         paging_init();
 396         strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 397         *cmdline_p = command_line;
 398         setup_hostinfo(host_info, sizeof host_info);
 399 }
 400
 401 void __init check_bugs(void)
 402 {
 403         arch_check_bugs();
 404         os_check_bugs();
 405 }
 406
 407 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 408 {
 409 }
 410
 411 #ifdef CONFIG_SMP
 412 void alternatives_smp_module_add(struct module *mod, char *name,
 413                                  void *locks, void *locks_end,
 414                                  void *text,  void *text_end)
 415 {
 416 }
 417
 418 void alternatives_smp_module_del(struct module *mod)
 419 {
 420 }
 421 #endif