[PATCH] cpuset: migrate all tasks in cpuset at once
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / init / main.c
CommitLineData
1da177e4
LT
1/*
2 * linux/init/main.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * GK 2/5/95 - Changed to support mounting root fs via NFS
7 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
10 */
11
12#define __KERNEL_SYSCALLS__
13
14#include <linux/config.h>
15#include <linux/types.h>
16#include <linux/module.h>
17#include <linux/proc_fs.h>
18#include <linux/devfs_fs_kernel.h>
19#include <linux/kernel.h>
20#include <linux/syscalls.h>
21#include <linux/string.h>
22#include <linux/ctype.h>
23#include <linux/delay.h>
24#include <linux/utsname.h>
25#include <linux/ioport.h>
26#include <linux/init.h>
27#include <linux/smp_lock.h>
28#include <linux/initrd.h>
29#include <linux/hdreg.h>
30#include <linux/bootmem.h>
31#include <linux/tty.h>
32#include <linux/gfp.h>
33#include <linux/percpu.h>
34#include <linux/kmod.h>
35#include <linux/kernel_stat.h>
36#include <linux/security.h>
37#include <linux/workqueue.h>
38#include <linux/profile.h>
39#include <linux/rcupdate.h>
40#include <linux/moduleparam.h>
41#include <linux/kallsyms.h>
42#include <linux/writeback.h>
43#include <linux/cpu.h>
44#include <linux/cpuset.h>
45#include <linux/efi.h>
46#include <linux/unistd.h>
47#include <linux/rmap.h>
48#include <linux/mempolicy.h>
49#include <linux/key.h>
50
51#include <asm/io.h>
52#include <asm/bugs.h>
53#include <asm/setup.h>
a940199f 54#include <asm/sections.h>
37b73c82 55#include <asm/cacheflush.h>
1da177e4
LT
56
57/*
58 * This is one of the first .c files built. Error out early
59 * if we have compiler trouble..
60 */
61#if __GNUC__ == 2 && __GNUC_MINOR__ == 96
62#ifdef CONFIG_FRAME_POINTER
63#error This compiler cannot compile correctly with frame pointers enabled
64#endif
65#endif
66
67#ifdef CONFIG_X86_LOCAL_APIC
68#include <asm/smp.h>
69#endif
70
71/*
72 * Versions of gcc older than that listed below may actually compile
73 * and link okay, but the end product can have subtle run time bugs.
74 * To avoid associated bogus bug reports, we flatly refuse to compile
75 * with a gcc that is known to be too old from the very beginning.
76 */
77#if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 95)
78#error Sorry, your GCC is too old. It builds incorrect kernels.
79#endif
80
81static int init(void *);
82
83extern void init_IRQ(void);
1da177e4
LT
84extern void fork_init(unsigned long);
85extern void mca_init(void);
86extern void sbus_init(void);
87extern void sysctl_init(void);
88extern void signals_init(void);
89extern void buffer_init(void);
90extern void pidhash_init(void);
91extern void pidmap_init(void);
92extern void prio_tree_init(void);
93extern void radix_tree_init(void);
94extern void free_initmem(void);
95extern void populate_rootfs(void);
96extern void driver_init(void);
97extern void prepare_namespace(void);
98#ifdef CONFIG_ACPI
99extern void acpi_early_init(void);
100#else
101static inline void acpi_early_init(void) { }
102#endif
37b73c82
AV
103#ifndef CONFIG_DEBUG_RODATA
104static inline void mark_rodata_ro(void) { }
105#endif
1da177e4
LT
106
107#ifdef CONFIG_TC
108extern void tc_init(void);
109#endif
110
111enum system_states system_state;
112EXPORT_SYMBOL(system_state);
113
114/*
115 * Boot command-line arguments
116 */
117#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
118#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
119
120extern void time_init(void);
121/* Default late time init is NULL. archs can override this later. */
122void (*late_time_init)(void);
123extern void softirq_init(void);
124
125/* Untouched command line (eg. for /proc) saved by arch-specific code. */
126char saved_command_line[COMMAND_LINE_SIZE];
127
128static char *execute_command;
ffdfc409 129static char *ramdisk_execute_command;
1da177e4
LT
130
131/* Setup configured maximum number of CPUs to activate */
132static unsigned int max_cpus = NR_CPUS;
133
134/*
135 * Setup routine for controlling SMP activation
136 *
137 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
138 * activation entirely (the MPS table probe still happens, though).
139 *
140 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
141 * greater than 0, limits the maximum number of CPUs activated in
142 * SMP mode to <NUM>.
143 */
144static int __init nosmp(char *str)
145{
146 max_cpus = 0;
147 return 1;
148}
149
150__setup("nosmp", nosmp);
151
152static int __init maxcpus(char *str)
153{
154 get_option(&str, &max_cpus);
155 return 1;
156}
157
158__setup("maxcpus=", maxcpus);
159
160static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
161char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
162static const char *panic_later, *panic_param;
163
164extern struct obs_kernel_param __setup_start[], __setup_end[];
165
166static int __init obsolete_checksetup(char *line)
167{
168 struct obs_kernel_param *p;
169
170 p = __setup_start;
171 do {
172 int n = strlen(p->str);
173 if (!strncmp(line, p->str, n)) {
174 if (p->early) {
175 /* Already done in parse_early_param? (Needs
176 * exact match on param part) */
177 if (line[n] == '\0' || line[n] == '=')
178 return 1;
179 } else if (!p->setup_func) {
180 printk(KERN_WARNING "Parameter %s is obsolete,"
181 " ignored\n", p->str);
182 return 1;
183 } else if (p->setup_func(line + n))
184 return 1;
185 }
186 p++;
187 } while (p < __setup_end);
188 return 0;
189}
190
191/*
192 * This should be approx 2 Bo*oMips to start (note initial shift), and will
193 * still work even if initially too large, it will just take slightly longer
194 */
195unsigned long loops_per_jiffy = (1<<12);
196
197EXPORT_SYMBOL(loops_per_jiffy);
198
199static int __init debug_kernel(char *str)
200{
201 if (*str)
202 return 0;
203 console_loglevel = 10;
204 return 1;
205}
206
207static int __init quiet_kernel(char *str)
208{
209 if (*str)
210 return 0;
211 console_loglevel = 4;
212 return 1;
213}
214
215__setup("debug", debug_kernel);
216__setup("quiet", quiet_kernel);
217
218static int __init loglevel(char *str)
219{
220 get_option(&str, &console_loglevel);
221 return 1;
222}
223
224__setup("loglevel=", loglevel);
225
226/*
227 * Unknown boot options get handed to init, unless they look like
228 * failed parameters
229 */
230static int __init unknown_bootoption(char *param, char *val)
231{
232 /* Change NUL term back to "=", to make "param" the whole string. */
233 if (val) {
234 /* param=val or param="val"? */
235 if (val == param+strlen(param)+1)
236 val[-1] = '=';
237 else if (val == param+strlen(param)+2) {
238 val[-2] = '=';
239 memmove(val-1, val, strlen(val)+1);
240 val--;
241 } else
242 BUG();
243 }
244
245 /* Handle obsolete-style parameters */
246 if (obsolete_checksetup(param))
247 return 0;
248
249 /*
250 * Preemptive maintenance for "why didn't my mispelled command
251 * line work?"
252 */
253 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
254 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
255 return 0;
256 }
257
258 if (panic_later)
259 return 0;
260
261 if (val) {
262 /* Environment option */
263 unsigned int i;
264 for (i = 0; envp_init[i]; i++) {
265 if (i == MAX_INIT_ENVS) {
266 panic_later = "Too many boot env vars at `%s'";
267 panic_param = param;
268 }
269 if (!strncmp(param, envp_init[i], val - param))
270 break;
271 }
272 envp_init[i] = param;
273 } else {
274 /* Command line option */
275 unsigned int i;
276 for (i = 0; argv_init[i]; i++) {
277 if (i == MAX_INIT_ARGS) {
278 panic_later = "Too many boot init vars at `%s'";
279 panic_param = param;
280 }
281 }
282 argv_init[i] = param;
283 }
284 return 0;
285}
286
287static int __init init_setup(char *str)
288{
289 unsigned int i;
290
291 execute_command = str;
292 /*
293 * In case LILO is going to boot us with default command line,
294 * it prepends "auto" before the whole cmdline which makes
295 * the shell think it should execute a script with such name.
296 * So we ignore all arguments entered _before_ init=... [MJ]
297 */
298 for (i = 1; i < MAX_INIT_ARGS; i++)
299 argv_init[i] = NULL;
300 return 1;
301}
302__setup("init=", init_setup);
303
ffdfc409
OJ
304static int __init rdinit_setup(char *str)
305{
306 unsigned int i;
307
308 ramdisk_execute_command = str;
309 /* See "auto" comment in init_setup */
310 for (i = 1; i < MAX_INIT_ARGS; i++)
311 argv_init[i] = NULL;
312 return 1;
313}
314__setup("rdinit=", rdinit_setup);
315
1da177e4
LT
316extern void setup_arch(char **);
317
318#ifndef CONFIG_SMP
319
320#ifdef CONFIG_X86_LOCAL_APIC
321static void __init smp_init(void)
322{
323 APIC_init_uniprocessor();
324}
325#else
326#define smp_init() do { } while (0)
327#endif
328
329static inline void setup_per_cpu_areas(void) { }
330static inline void smp_prepare_cpus(unsigned int maxcpus) { }
331
332#else
333
334#ifdef __GENERIC_PER_CPU
335unsigned long __per_cpu_offset[NR_CPUS];
336
337EXPORT_SYMBOL(__per_cpu_offset);
338
339static void __init setup_per_cpu_areas(void)
340{
341 unsigned long size, i;
342 char *ptr;
1da177e4
LT
343
344 /* Copy section for each CPU (we discard the original) */
345 size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
346#ifdef CONFIG_MODULES
347 if (size < PERCPU_ENOUGH_ROOM)
348 size = PERCPU_ENOUGH_ROOM;
349#endif
350
351 ptr = alloc_bootmem(size * NR_CPUS);
352
353 for (i = 0; i < NR_CPUS; i++, ptr += size) {
354 __per_cpu_offset[i] = ptr - __per_cpu_start;
355 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
356 }
357}
358#endif /* !__GENERIC_PER_CPU */
359
360/* Called by boot processor to activate the rest. */
361static void __init smp_init(void)
362{
363 unsigned int i;
364
365 /* FIXME: This should be done in userspace --RR */
366 for_each_present_cpu(i) {
367 if (num_online_cpus() >= max_cpus)
368 break;
369 if (!cpu_online(i))
370 cpu_up(i);
371 }
372
373 /* Any cleanup work */
374 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
375 smp_cpus_done(max_cpus);
376#if 0
377 /* Get other processors into their bootup holding patterns. */
378
379 smp_commence();
380#endif
381}
382
383#endif
384
385/*
386 * We need to finalize in a non-__init function or else race conditions
387 * between the root thread and the init thread may cause start_kernel to
388 * be reaped by free_initmem before the root thread has proceeded to
389 * cpu_idle.
390 *
391 * gcc-3.4 accidentally inlines this function, so use noinline.
392 */
393
394static void noinline rest_init(void)
395 __releases(kernel_lock)
396{
397 kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
398 numa_default_policy();
399 unlock_kernel();
f340c0d1
IM
400
401 /*
402 * The boot idle thread must execute schedule()
403 * at least one to get things moving:
404 */
5bfb5d69 405 preempt_enable_no_resched();
f340c0d1 406 schedule();
5bfb5d69 407 preempt_disable();
f340c0d1 408
5bfb5d69 409 /* Call into cpu_idle with preempt disabled */
1da177e4
LT
410 cpu_idle();
411}
412
413/* Check for early params. */
414static int __init do_early_param(char *param, char *val)
415{
416 struct obs_kernel_param *p;
417
418 for (p = __setup_start; p < __setup_end; p++) {
419 if (p->early && strcmp(param, p->str) == 0) {
420 if (p->setup_func(val) != 0)
421 printk(KERN_WARNING
422 "Malformed early option '%s'\n", param);
423 }
424 }
425 /* We accept everything at this stage. */
426 return 0;
427}
428
429/* Arch code calls this early on, or if not, just before other parsing. */
430void __init parse_early_param(void)
431{
432 static __initdata int done = 0;
433 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
434
435 if (done)
436 return;
437
438 /* All fall through to do_early_param. */
439 strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
440 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
441 done = 1;
442}
443
444/*
445 * Activate the first processor.
446 */
447
448asmlinkage void __init start_kernel(void)
449{
450 char * command_line;
451 extern struct kernel_param __start___param[], __stop___param[];
452/*
453 * Interrupts are still disabled. Do necessary setups, then
454 * enable them
455 */
456 lock_kernel();
457 page_address_init();
458 printk(KERN_NOTICE);
459 printk(linux_banner);
460 setup_arch(&command_line);
461 setup_per_cpu_areas();
462
463 /*
464 * Mark the boot cpu "online" so that it can call console drivers in
465 * printk() and can access its per-cpu storage.
466 */
467 smp_prepare_boot_cpu();
468
469 /*
470 * Set up the scheduler prior starting any interrupts (such as the
471 * timer interrupt). Full topology setup happens at smp_init()
472 * time - but meanwhile we still have a functioning scheduler.
473 */
474 sched_init();
475 /*
476 * Disable preemption - early bootup scheduling is extremely
477 * fragile until we cpu_idle() for the first time.
478 */
479 preempt_disable();
480 build_all_zonelists();
481 page_alloc_init();
482 printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line);
483 parse_early_param();
484 parse_args("Booting kernel", command_line, __start___param,
485 __stop___param - __start___param,
486 &unknown_bootoption);
487 sort_main_extable();
488 trap_init();
489 rcu_init();
490 init_IRQ();
491 pidhash_init();
492 init_timers();
493 softirq_init();
494 time_init();
495
496 /*
497 * HACK ALERT! This is early. We're enabling the console before
498 * we've done PCI setups etc, and console_init() must be aware of
499 * this. But we do want output early, in case something goes wrong.
500 */
501 console_init();
502 if (panic_later)
503 panic(panic_later, panic_param);
504 profile_init();
505 local_irq_enable();
506#ifdef CONFIG_BLK_DEV_INITRD
507 if (initrd_start && !initrd_below_start_ok &&
508 initrd_start < min_low_pfn << PAGE_SHIFT) {
509 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
510 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
511 initrd_start = 0;
512 }
513#endif
514 vfs_caches_init_early();
515 mem_init();
516 kmem_cache_init();
e7c8d5c9 517 setup_per_cpu_pageset();
1da177e4
LT
518 numa_policy_init();
519 if (late_time_init)
520 late_time_init();
521 calibrate_delay();
522 pidmap_init();
523 pgtable_cache_init();
524 prio_tree_init();
525 anon_vma_init();
526#ifdef CONFIG_X86
527 if (efi_enabled)
528 efi_enter_virtual_mode();
529#endif
530 fork_init(num_physpages);
531 proc_caches_init();
532 buffer_init();
533 unnamed_dev_init();
534 key_init();
535 security_init();
536 vfs_caches_init(num_physpages);
537 radix_tree_init();
538 signals_init();
539 /* rootfs populating might need page-writeback */
540 page_writeback_init();
541#ifdef CONFIG_PROC_FS
542 proc_root_init();
543#endif
544 cpuset_init();
545
546 check_bugs();
547
548 acpi_early_init(); /* before LAPIC and SMP init */
549
550 /* Do the rest non-__init'ed, we're now alive */
551 rest_init();
552}
553
554static int __initdata initcall_debug;
555
556static int __init initcall_debug_setup(char *str)
557{
558 initcall_debug = 1;
559 return 1;
560}
561__setup("initcall_debug", initcall_debug_setup);
562
563struct task_struct *child_reaper = &init_task;
564
565extern initcall_t __initcall_start[], __initcall_end[];
566
567static void __init do_initcalls(void)
568{
569 initcall_t *call;
570 int count = preempt_count();
571
572 for (call = __initcall_start; call < __initcall_end; call++) {
573 char *msg;
574
575 if (initcall_debug) {
576 printk(KERN_DEBUG "Calling initcall 0x%p", *call);
577 print_fn_descriptor_symbol(": %s()", (unsigned long) *call);
578 printk("\n");
579 }
580
581 (*call)();
582
583 msg = NULL;
584 if (preempt_count() != count) {
585 msg = "preemption imbalance";
586 preempt_count() = count;
587 }
588 if (irqs_disabled()) {
589 msg = "disabled interrupts";
590 local_irq_enable();
591 }
592 if (msg) {
593 printk(KERN_WARNING "error in initcall at 0x%p: "
594 "returned with %s\n", *call, msg);
595 }
596 }
597
598 /* Make sure there is no pending stuff from the initcall sequence */
599 flush_scheduled_work();
600}
601
602/*
603 * Ok, the machine is now initialized. None of the devices
604 * have been touched yet, but the CPU subsystem is up and
605 * running, and memory and process management works.
606 *
607 * Now we can finally start doing some real work..
608 */
609static void __init do_basic_setup(void)
610{
611 /* drivers will send hotplug events */
612 init_workqueues();
613 usermodehelper_init();
614 driver_init();
615
616#ifdef CONFIG_SYSCTL
617 sysctl_init();
618#endif
619
1da177e4
LT
620 do_initcalls();
621}
622
623static void do_pre_smp_initcalls(void)
624{
625 extern int spawn_ksoftirqd(void);
626#ifdef CONFIG_SMP
627 extern int migration_init(void);
628
629 migration_init();
630#endif
631 spawn_ksoftirqd();
8446f1d3 632 spawn_softlockup_task();
1da177e4
LT
633}
634
635static void run_init_process(char *init_filename)
636{
637 argv_init[0] = init_filename;
638 execve(init_filename, argv_init, envp_init);
639}
640
641static inline void fixup_cpu_present_map(void)
642{
643#ifdef CONFIG_SMP
644 int i;
645
646 /*
647 * If arch is not hotplug ready and did not populate
648 * cpu_present_map, just make cpu_present_map same as cpu_possible_map
649 * for other cpu bringup code to function as normal. e.g smp_init() etc.
650 */
651 if (cpus_empty(cpu_present_map)) {
652 for_each_cpu(i) {
653 cpu_set(i, cpu_present_map);
654 }
655 }
656#endif
657}
658
659static int init(void * unused)
660{
661 lock_kernel();
662 /*
663 * init can run on any cpu.
664 */
665 set_cpus_allowed(current, CPU_MASK_ALL);
666 /*
667 * Tell the world that we're going to be the grim
668 * reaper of innocent orphaned children.
669 *
670 * We don't want people to have to make incorrect
671 * assumptions about where in the task array this
672 * can be found.
673 */
674 child_reaper = current;
675
676 /* Sets up cpus_possible() */
677 smp_prepare_cpus(max_cpus);
678
679 do_pre_smp_initcalls();
680
681 fixup_cpu_present_map();
682 smp_init();
683 sched_init_smp();
684
685 cpuset_init_smp();
686
687 /*
688 * Do this before initcalls, because some drivers want to access
689 * firmware files.
690 */
691 populate_rootfs();
692
693 do_basic_setup();
694
695 /*
696 * check if there is an early userspace init. If yes, let it do all
697 * the work
698 */
ffdfc409
OJ
699
700 if (!ramdisk_execute_command)
701 ramdisk_execute_command = "/init";
702
703 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
704 ramdisk_execute_command = NULL;
1da177e4 705 prepare_namespace();
ffdfc409 706 }
1da177e4
LT
707
708 /*
709 * Ok, we have completed the initial bootup, and
710 * we're essentially up and running. Get rid of the
711 * initmem segments and start the user-mode stuff..
712 */
713 free_initmem();
714 unlock_kernel();
37b73c82 715 mark_rodata_ro();
1da177e4
LT
716 system_state = SYSTEM_RUNNING;
717 numa_default_policy();
718
719 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
720 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
721
722 (void) sys_dup(0);
723 (void) sys_dup(0);
ffdfc409
OJ
724
725 if (ramdisk_execute_command) {
726 run_init_process(ramdisk_execute_command);
727 printk(KERN_WARNING "Failed to execute %s\n",
728 ramdisk_execute_command);
729 }
730
1da177e4
LT
731 /*
732 * We try each of these until one succeeds.
733 *
734 * The Bourne shell can be used instead of init if we are
735 * trying to recover a really broken machine.
736 */
c1d7ef70 737 if (execute_command) {
1da177e4 738 run_init_process(execute_command);
c1d7ef70
BA
739 printk(KERN_WARNING "Failed to execute %s. Attempting "
740 "defaults...\n", execute_command);
741 }
1da177e4
LT
742 run_init_process("/sbin/init");
743 run_init_process("/etc/init");
744 run_init_process("/bin/init");
745 run_init_process("/bin/sh");
746
747 panic("No init found. Try passing init= option to kernel.");
748}