aa7b067565d9ffe5870b34eaeff80a131994f389
[linux-2.6.git] / 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