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