SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/um/kernel/um_arch.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/delay.h"
   7 #include "linux/mm.h"
   8 #include "linux/module.h"
   9 #include "linux/seq_file.h"
  10 #include "linux/string.h"
  11 #include "linux/utsname.h"
  12 #include "asm/pgtable.h"
  13 #include "asm/processor.h"
  14 #include "asm/setup.h"
  15 #include "arch.h"
  16 #include "as-layout.h"
  17 #include "init.h"
  18 #include "kern.h"
  19 #include "kern_util.h"
  20 #include "mem_user.h"
  21 #include "os.h"
  22 #include "skas.h"
  23
  24 #define DEFAULT_COMMAND_LINE "root=98:0"
  25
  26 /* Changed in add_arg and setup_arch, which run before SMP is started */
  27 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
  28
  29 static void __init add_arg(char *arg)
  30 {
  31         if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
  32                 printf("add_arg: Too many command line arguments!\n");
  33                 exit(1);
  34         }
  35         if (strlen(command_line) > 0)
  36                 strcat(command_line, " ");
  37         strcat(command_line, arg);
  38 }
  39
  40 /*
  41  * These fields are initialized at boot time and not changed.
  42  * XXX This structure is used only in the non-SMP case.  Maybe this
  43  * should be moved to smp.c.
  44  */
  45 struct cpuinfo_um boot_cpu_data = {
  46         .loops_per_jiffy        = 0,
  47         .ipi_pipe               = { -1, -1 }
  48 };
  49
  50 unsigned long thread_saved_pc(struct task_struct *task)
  51 {
  52         /* FIXME: Need to look up userspace_pid by cpu */
  53         return os_process_pc(userspace_pid[0]);
  54 }
  55
  56 /* Changed in setup_arch, which is called in early boot */
  57 static char host_info[(__NEW_UTS_LEN + 1) * 5];
  58
  59 static int show_cpuinfo(struct seq_file *m, void *v)
  60 {
  61         int index = 0;
  62
  63 #ifdef CONFIG_SMP
  64         index = (struct cpuinfo_um *) v - cpu_data;
  65         if (!cpu_online(index))
  66                 return 0;
  67 #endif
  68
  69         seq_printf(m, "processor\t: %d\n", index);
  70         seq_printf(m, "vendor_id\t: User Mode Linux\n");
  71         seq_printf(m, "model name\t: UML\n");
  72         seq_printf(m, "mode\t\t: skas\n");
  73         seq_printf(m, "host\t\t: %s\n", host_info);
  74         seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
  75                    loops_per_jiffy/(500000/HZ),
  76                    (loops_per_jiffy/(5000/HZ)) % 100);
  77
  78         return 0;
  79 }
  80
  81 static void *c_start(struct seq_file *m, loff_t *pos)
  82 {
  83         return *pos < NR_CPUS ? cpu_data + *pos : NULL;
  84 }
  85
  86 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  87 {
  88         ++*pos;
  89         return c_start(m, pos);
  90 }
  91
  92 static void c_stop(struct seq_file *m, void *v)
  93 {
  94 }
  95
  96 const struct seq_operations cpuinfo_op = {
  97         .start  = c_start,
  98         .next   = c_next,
  99         .stop   = c_stop,
 100         .show   = show_cpuinfo,
 101 };
 102
 103 /* Set in linux_main */
 104 unsigned long host_task_size;
 105 unsigned long task_size;
 106 unsigned long uml_physmem;
 107 unsigned long uml_reserved; /* Also modified in mem_init */
 108 unsigned long start_vm;
 109 unsigned long end_vm;
 110
 111 /* Set in uml_ncpus_setup */
 112 int ncpus = 1;
 113
 114 /* Set in early boot */
 115 static int have_root __initdata = 0;
 116
 117 /* Set in uml_mem_setup and modified in linux_main */
 118 long long physmem_size = 32 * 1024 * 1024;
 119
 120 static char *usage_string =
 121 "User Mode Linux v%s\n"
 122 "       available at http://user-mode-linux.sourceforge.net/\n\n";
 123
 124 static int __init uml_version_setup(char *line, int *add)
 125 {
 126         printf("%s\n", init_utsname()->release);
 127         exit(0);
 128
 129         return 0;
 130 }
 131
 132 __uml_setup("--version", uml_version_setup,
 133 "--version\n"
 134 "    Prints the version number of the kernel.\n\n"
 135 );
 136
 137 static int __init uml_root_setup(char *line, int *add)
 138 {
 139         have_root = 1;
 140         return 0;
 141 }
 142
 143 __uml_setup("root=", uml_root_setup,
 144 "root=<file containing the root fs>\n"
 145 "    This is actually used by the generic kernel in exactly the same\n"
 146 "    way as in any other kernel. If you configure a number of block\n"
 147 "    devices and want to boot off something other than ubd0, you \n"
 148 "    would use something like:\n"
 149 "        root=/dev/ubd5\n\n"
 150 );
 151
 152 static int __init no_skas_debug_setup(char *line, int *add)
 153 {
 154         printf("'debug' is not necessary to gdb UML in skas mode - run \n");
 155         printf("'gdb linux'");
 156
 157         return 0;
 158 }
 159
 160 __uml_setup("debug", no_skas_debug_setup,
 161 "debug\n"
 162 "    this flag is not needed to run gdb on UML in skas mode\n\n"
 163 );
 164
 165 #ifdef CONFIG_SMP
 166 static int __init uml_ncpus_setup(char *line, int *add)
 167 {
 168         if (!sscanf(line, "%d", &ncpus)) {
 169                 printf("Couldn't parse [%s]\n", line);
 170                 return -1;
 171         }
 172
 173         return 0;
 174 }
 175
 176 __uml_setup("ncpus=", uml_ncpus_setup,
 177 "ncpus=<# of desired CPUs>\n"
 178 "    This tells an SMP kernel how many virtual processors to start.\n\n"
 179 );
 180 #endif
 181
 182 static int __init Usage(char *line, int *add)
 183 {
 184         const char **p;
 185
 186         printf(usage_string, init_utsname()->release);
 187         p = &__uml_help_start;
 188         while (p < &__uml_help_end) {
 189                 printf("%s", *p);
 190                 p++;
 191         }
 192         exit(0);
 193         return 0;
 194 }
 195
 196 __uml_setup("--help", Usage,
 197 "--help\n"
 198 "    Prints this message.\n\n"
 199 );
 200
 201 static void __init uml_checksetup(char *line, int *add)
 202 {
 203         struct uml_param *p;
 204
 205         p = &__uml_setup_start;
 206         while(p < &__uml_setup_end) {
 207                 int n;
 208
 209                 n = strlen(p->str);
 210                 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
 211                         return;
 212                 p++;
 213         }
 214 }
 215
 216 static void __init uml_postsetup(void)
 217 {
 218         initcall_t *p;
 219
 220         p = &__uml_postsetup_start;
 221         while(p < &__uml_postsetup_end) {
 222                 (*p)();
 223                 p++;
 224         }
 225         return;
 226 }
 227
 228 /* Set during early boot */
 229 unsigned long brk_start;
 230 unsigned long end_iomem;
 231 EXPORT_SYMBOL(end_iomem);
 232
 233 #define MIN_VMALLOC (32 * 1024 * 1024)
 234
 235 extern char __binary_start;
 236
 237 static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
 238 {
 239         /* Round up to the nearest 4M */
 240         unsigned long host_task_size = ROUND_4M((unsigned long)
 241                                                 &host_task_size);
 242
 243         if (!skas_needs_stub)
 244                 *task_size_out = host_task_size;
 245         else
 246                 *task_size_out = STUB_START & PGDIR_MASK;
 247
 248         return host_task_size;
 249 }
 250
 251 int __init linux_main(int argc, char **argv)
 252 {
 253         unsigned long avail, diff;
 254         unsigned long virtmem_size, max_physmem;
 255         unsigned int i, add;
 256         char * mode;
 257
 258         for (i = 1; i < argc; i++) {
 259                 if ((i == 1) && (argv[i][0] == ' '))
 260                         continue;
 261                 add = 1;
 262                 uml_checksetup(argv[i], &add);
 263                 if (add)
 264                         add_arg(argv[i]);
 265         }
 266         if (have_root == 0)
 267                 add_arg(DEFAULT_COMMAND_LINE);
 268
 269         /* OS sanity checks that need to happen before the kernel runs */
 270         os_early_checks();
 271
 272         can_do_skas();
 273
 274         if (proc_mm && ptrace_faultinfo)
 275                 mode = "SKAS3";
 276         else
 277                 mode = "SKAS0";
 278
 279         printf("UML running in %s mode\n", mode);
 280
 281         host_task_size = set_task_sizes_skas(&task_size);
 282
 283         brk_start = (unsigned long) sbrk(0);
 284
 285         /*
 286          * Increase physical memory size for exec-shield users
 287          * so they actually get what they asked for. This should
 288          * add zero for non-exec shield users
 289          */
 290
 291         diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 292         if (diff > 1024 * 1024) {
 293                 printf("Adding %ld bytes to physical memory to account for "
 294                        "exec-shield gap\n", diff);
 295                 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 296         }
 297
 298         uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
 299
 300         /* Reserve up to 4M after the current brk */
 301         uml_reserved = ROUND_4M(brk_start) + (1 << 22);
 302
 303         setup_machinename(init_utsname()->machine);
 304
 305         highmem = 0;
 306         iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
 307         max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
 308
 309         /*
 310          * Zones have to begin on a 1 << MAX_ORDER page boundary,
 311          * so this makes sure that's true for highmem
 312          */
 313         max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
 314         if (physmem_size + iomem_size > max_physmem) {
 315                 highmem = physmem_size + iomem_size - max_physmem;
 316                 physmem_size -= highmem;
 317 #ifndef CONFIG_HIGHMEM
 318                 highmem = 0;
 319                 printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
 320                        "to %Lu bytes\n", physmem_size);
 321 #endif
 322         }
 323
 324         high_physmem = uml_physmem + physmem_size;
 325         end_iomem = high_physmem + iomem_size;
 326         high_memory = (void *) end_iomem;
 327
 328         start_vm = VMALLOC_START;
 329
 330         setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
 331         if (init_maps(physmem_size, iomem_size, highmem)) {
 332                 printf("Failed to allocate mem_map for %Lu bytes of physical "
 333                        "memory and %Lu bytes of highmem\n", physmem_size,
 334                        highmem);
 335                 exit(1);
 336         }
 337
 338         virtmem_size = physmem_size;
 339         avail = get_kmem_end() - start_vm;
 340         if (physmem_size > avail)
 341                 virtmem_size = avail;
 342         end_vm = start_vm + virtmem_size;
 343
 344         if (virtmem_size < physmem_size)
 345                 printf("Kernel virtual memory size shrunk to %lu bytes\n",
 346                        virtmem_size);
 347
 348         uml_postsetup();
 349
 350         stack_protections((unsigned long) &init_thread_info);
 351         os_flush_stdout();
 352
 353         return start_uml();
 354 }
 355
 356 extern int uml_exitcode;
 357
 358 static int panic_exit(struct notifier_block *self, unsigned long unused1,
 359                       void *unused2)
 360 {
 361         bust_spinlocks(1);
 362         show_regs(&(current->thread.regs));
 363         bust_spinlocks(0);
 364         uml_exitcode = 1;
 365         os_dump_core();
 366         return 0;
 367 }
 368
 369 static struct notifier_block panic_exit_notifier = {
 370         .notifier_call          = panic_exit,
 371         .next                   = NULL,
 372         .priority               = 0
 373 };
 374
 375 void __init setup_arch(char **cmdline_p)
 376 {
 377         atomic_notifier_chain_register(&panic_notifier_list,
 378                         &panic_exit_notifier);
 379         paging_init();
 380         strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 381         *cmdline_p = command_line;
 382         setup_hostinfo(host_info, sizeof host_info);
 383 }
 384
 385 void __init check_bugs(void)
 386 {
 387         arch_check_bugs();
 388         os_check_bugs();
 389 }
 390
 391 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 392 {
 393 }
 394
 395 #ifdef CONFIG_SMP
 396 void alternatives_smp_module_add(struct module *mod, char *name,
 397                                  void *locks, void *locks_end,
 398                                  void *text,  void *text_end)
 399 {
 400 }
 401
 402 void alternatives_smp_module_del(struct module *mod)
 403 {
 404 }
 405 #endif