Merge branch 'next' of git://selinuxproject.org/~jmorris/linux-security
[linux-btrfs-devel.git] / arch / um / kernel / um_arch.c
blob8d84250324b3d2c41d2a6718e7fd0531ecd025b4
1 /*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
6 #include <linux/delay.h>
7 #include <linux/init.h>
8 #include <linux/mm.h>
9 #include <linux/module.h>
10 #include <linux/seq_file.h>
11 #include <linux/string.h>
12 #include <linux/utsname.h>
13 #include <asm/pgtable.h>
14 #include <asm/processor.h>
15 #include <asm/setup.h>
16 #include "as-layout.h"
17 #include "arch.h"
18 #include "init.h"
19 #include "kern.h"
20 #include "kern_util.h"
21 #include "mem_user.h"
22 #include "os.h"
24 #define DEFAULT_COMMAND_LINE "root=98:0"
26 /* Changed in add_arg and setup_arch, which run before SMP is started */
27 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
29 static void __init add_arg(char *arg)
31 if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
32 printf("add_arg: Too many command line arguments!\n");
33 exit(1);
35 if (strlen(command_line) > 0)
36 strcat(command_line, " ");
37 strcat(command_line, arg);
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.
45 struct cpuinfo_um boot_cpu_data = {
46 .loops_per_jiffy = 0,
47 .ipi_pipe = { -1, -1 }
50 unsigned long thread_saved_pc(struct task_struct *task)
52 /* FIXME: Need to look up userspace_pid by cpu */
53 return os_process_pc(userspace_pid[0]);
56 /* Changed in setup_arch, which is called in early boot */
57 static char host_info[(__NEW_UTS_LEN + 1) * 5];
59 static int show_cpuinfo(struct seq_file *m, void *v)
61 int index = 0;
63 #ifdef CONFIG_SMP
64 index = (struct cpuinfo_um *) v - cpu_data;
65 if (!cpu_online(index))
66 return 0;
67 #endif
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);
78 return 0;
81 static void *c_start(struct seq_file *m, loff_t *pos)
83 return *pos < NR_CPUS ? cpu_data + *pos : NULL;
86 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
88 ++*pos;
89 return c_start(m, pos);
92 static void c_stop(struct seq_file *m, void *v)
96 const struct seq_operations cpuinfo_op = {
97 .start = c_start,
98 .next = c_next,
99 .stop = c_stop,
100 .show = show_cpuinfo,
103 /* Set in linux_main */
104 unsigned long uml_physmem;
105 unsigned long uml_reserved; /* Also modified in mem_init */
106 unsigned long start_vm;
107 unsigned long end_vm;
109 /* Set in uml_ncpus_setup */
110 int ncpus = 1;
112 /* Set in early boot */
113 static int have_root __initdata = 0;
115 /* Set in uml_mem_setup and modified in linux_main */
116 long long physmem_size = 32 * 1024 * 1024;
118 static const char *usage_string =
119 "User Mode Linux v%s\n"
120 " available at http://user-mode-linux.sourceforge.net/\n\n";
122 static int __init uml_version_setup(char *line, int *add)
124 printf("%s\n", init_utsname()->release);
125 exit(0);
127 return 0;
130 __uml_setup("--version", uml_version_setup,
131 "--version\n"
132 " Prints the version number of the kernel.\n\n"
135 static int __init uml_root_setup(char *line, int *add)
137 have_root = 1;
138 return 0;
141 __uml_setup("root=", uml_root_setup,
142 "root=<file containing the root fs>\n"
143 " This is actually used by the generic kernel in exactly the same\n"
144 " way as in any other kernel. If you configure a number of block\n"
145 " devices and want to boot off something other than ubd0, you \n"
146 " would use something like:\n"
147 " root=/dev/ubd5\n\n"
150 static int __init no_skas_debug_setup(char *line, int *add)
152 printf("'debug' is not necessary to gdb UML in skas mode - run \n");
153 printf("'gdb linux'\n");
155 return 0;
158 __uml_setup("debug", no_skas_debug_setup,
159 "debug\n"
160 " this flag is not needed to run gdb on UML in skas mode\n\n"
163 #ifdef CONFIG_SMP
164 static int __init uml_ncpus_setup(char *line, int *add)
166 if (!sscanf(line, "%d", &ncpus)) {
167 printf("Couldn't parse [%s]\n", line);
168 return -1;
171 return 0;
174 __uml_setup("ncpus=", uml_ncpus_setup,
175 "ncpus=<# of desired CPUs>\n"
176 " This tells an SMP kernel how many virtual processors to start.\n\n"
178 #endif
180 static int __init Usage(char *line, int *add)
182 const char **p;
184 printf(usage_string, init_utsname()->release);
185 p = &__uml_help_start;
186 while (p < &__uml_help_end) {
187 printf("%s", *p);
188 p++;
190 exit(0);
191 return 0;
194 __uml_setup("--help", Usage,
195 "--help\n"
196 " Prints this message.\n\n"
199 static void __init uml_checksetup(char *line, int *add)
201 struct uml_param *p;
203 p = &__uml_setup_start;
204 while (p < &__uml_setup_end) {
205 size_t n;
207 n = strlen(p->str);
208 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
209 return;
210 p++;
214 static void __init uml_postsetup(void)
216 initcall_t *p;
218 p = &__uml_postsetup_start;
219 while (p < &__uml_postsetup_end) {
220 (*p)();
221 p++;
223 return;
226 static int panic_exit(struct notifier_block *self, unsigned long unused1,
227 void *unused2)
229 bust_spinlocks(1);
230 show_regs(&(current->thread.regs));
231 bust_spinlocks(0);
232 uml_exitcode = 1;
233 os_dump_core();
234 return 0;
237 static struct notifier_block panic_exit_notifier = {
238 .notifier_call = panic_exit,
239 .next = NULL,
240 .priority = 0
243 /* Set during early boot */
244 unsigned long task_size;
245 EXPORT_SYMBOL(task_size);
247 unsigned long host_task_size;
249 unsigned long brk_start;
250 unsigned long end_iomem;
251 EXPORT_SYMBOL(end_iomem);
253 #define MIN_VMALLOC (32 * 1024 * 1024)
255 extern char __binary_start;
257 int __init linux_main(int argc, char **argv)
259 unsigned long avail, diff;
260 unsigned long virtmem_size, max_physmem;
261 unsigned long stack;
262 unsigned int i;
263 int add;
264 char * mode;
266 for (i = 1; i < argc; i++) {
267 if ((i == 1) && (argv[i][0] == ' '))
268 continue;
269 add = 1;
270 uml_checksetup(argv[i], &add);
271 if (add)
272 add_arg(argv[i]);
274 if (have_root == 0)
275 add_arg(DEFAULT_COMMAND_LINE);
277 host_task_size = os_get_top_address();
279 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
280 * out
282 task_size = host_task_size & PGDIR_MASK;
284 /* OS sanity checks that need to happen before the kernel runs */
285 os_early_checks();
287 can_do_skas();
289 if (proc_mm && ptrace_faultinfo)
290 mode = "SKAS3";
291 else
292 mode = "SKAS0";
294 printf("UML running in %s mode\n", mode);
296 brk_start = (unsigned long) sbrk(0);
299 * Increase physical memory size for exec-shield users
300 * so they actually get what they asked for. This should
301 * add zero for non-exec shield users
304 diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
305 if (diff > 1024 * 1024) {
306 printf("Adding %ld bytes to physical memory to account for "
307 "exec-shield gap\n", diff);
308 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
311 uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
313 /* Reserve up to 4M after the current brk */
314 uml_reserved = ROUND_4M(brk_start) + (1 << 22);
316 setup_machinename(init_utsname()->machine);
318 highmem = 0;
319 iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
320 max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
323 * Zones have to begin on a 1 << MAX_ORDER page boundary,
324 * so this makes sure that's true for highmem
326 max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
327 if (physmem_size + iomem_size > max_physmem) {
328 highmem = physmem_size + iomem_size - max_physmem;
329 physmem_size -= highmem;
330 #ifndef CONFIG_HIGHMEM
331 highmem = 0;
332 printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
333 "to %Lu bytes\n", physmem_size);
334 #endif
337 high_physmem = uml_physmem + physmem_size;
338 end_iomem = high_physmem + iomem_size;
339 high_memory = (void *) end_iomem;
341 start_vm = VMALLOC_START;
343 setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
344 if (init_maps(physmem_size, iomem_size, highmem)) {
345 printf("Failed to allocate mem_map for %Lu bytes of physical "
346 "memory and %Lu bytes of highmem\n", physmem_size,
347 highmem);
348 exit(1);
351 virtmem_size = physmem_size;
352 stack = (unsigned long) argv;
353 stack &= ~(1024 * 1024 - 1);
354 avail = stack - start_vm;
355 if (physmem_size > avail)
356 virtmem_size = avail;
357 end_vm = start_vm + virtmem_size;
359 if (virtmem_size < physmem_size)
360 printf("Kernel virtual memory size shrunk to %lu bytes\n",
361 virtmem_size);
363 atomic_notifier_chain_register(&panic_notifier_list,
364 &panic_exit_notifier);
366 uml_postsetup();
368 stack_protections((unsigned long) &init_thread_info);
369 os_flush_stdout();
371 return start_uml();
374 void __init setup_arch(char **cmdline_p)
376 paging_init();
377 strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
378 *cmdline_p = command_line;
379 setup_hostinfo(host_info, sizeof host_info);
382 void __init check_bugs(void)
384 arch_check_bugs();
385 os_check_bugs();
388 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
392 #ifdef CONFIG_SMP
393 void alternatives_smp_module_add(struct module *mod, char *name,
394 void *locks, void *locks_end,
395 void *text, void *text_end)
399 void alternatives_smp_module_del(struct module *mod)
402 #endif