xref: /linux-6.15/init/main.c (revision d0ea3d7d)
11da177e4SLinus Torvalds /*
21da177e4SLinus Torvalds  *  linux/init/main.c
31da177e4SLinus Torvalds  *
41da177e4SLinus Torvalds  *  Copyright (C) 1991, 1992  Linus Torvalds
51da177e4SLinus Torvalds  *
61da177e4SLinus Torvalds  *  GK 2/5/95  -  Changed to support mounting root fs via NFS
71da177e4SLinus Torvalds  *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
81da177e4SLinus Torvalds  *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
91da177e4SLinus Torvalds  *  Simplified starting of init:  Michael A. Griffith <[email protected]>
101da177e4SLinus Torvalds  */
111da177e4SLinus Torvalds 
121da177e4SLinus Torvalds #include <linux/types.h>
131da177e4SLinus Torvalds #include <linux/module.h>
141da177e4SLinus Torvalds #include <linux/proc_fs.h>
151da177e4SLinus Torvalds #include <linux/kernel.h>
161da177e4SLinus Torvalds #include <linux/syscalls.h>
171da177e4SLinus Torvalds #include <linux/string.h>
181da177e4SLinus Torvalds #include <linux/ctype.h>
191da177e4SLinus Torvalds #include <linux/delay.h>
201da177e4SLinus Torvalds #include <linux/utsname.h>
211da177e4SLinus Torvalds #include <linux/ioport.h>
221da177e4SLinus Torvalds #include <linux/init.h>
231da177e4SLinus Torvalds #include <linux/smp_lock.h>
241da177e4SLinus Torvalds #include <linux/initrd.h>
251da177e4SLinus Torvalds #include <linux/bootmem.h>
261da177e4SLinus Torvalds #include <linux/tty.h>
271da177e4SLinus Torvalds #include <linux/gfp.h>
281da177e4SLinus Torvalds #include <linux/percpu.h>
291da177e4SLinus Torvalds #include <linux/kmod.h>
30db64fe02SNick Piggin #include <linux/vmalloc.h>
311da177e4SLinus Torvalds #include <linux/kernel_stat.h>
32d7cd5611SRusty Russell #include <linux/start_kernel.h>
331da177e4SLinus Torvalds #include <linux/security.h>
343d442233SJens Axboe #include <linux/smp.h>
351da177e4SLinus Torvalds #include <linux/workqueue.h>
361da177e4SLinus Torvalds #include <linux/profile.h>
371da177e4SLinus Torvalds #include <linux/rcupdate.h>
381da177e4SLinus Torvalds #include <linux/moduleparam.h>
391da177e4SLinus Torvalds #include <linux/kallsyms.h>
401da177e4SLinus Torvalds #include <linux/writeback.h>
411da177e4SLinus Torvalds #include <linux/cpu.h>
421da177e4SLinus Torvalds #include <linux/cpuset.h>
43ddbcc7e8SPaul Menage #include <linux/cgroup.h>
441da177e4SLinus Torvalds #include <linux/efi.h>
45906568c9SThomas Gleixner #include <linux/tick.h>
466168a702SAndrew Morton #include <linux/interrupt.h>
47c757249aSShailabh Nagar #include <linux/taskstats_kern.h>
48ca74e92bSShailabh Nagar #include <linux/delayacct.h>
491da177e4SLinus Torvalds #include <linux/unistd.h>
501da177e4SLinus Torvalds #include <linux/rmap.h>
511da177e4SLinus Torvalds #include <linux/mempolicy.h>
521da177e4SLinus Torvalds #include <linux/key.h>
534552d5dcSJan Beulich #include <linux/unwind.h>
54b6cd0b77SAdrian Bunk #include <linux/buffer_head.h>
559a11b49aSIngo Molnar #include <linux/debug_locks.h>
563ac7fe5aSThomas Gleixner #include <linux/debugobjects.h>
57fbb9ce95SIngo Molnar #include <linux/lockdep.h>
5884d73786SSukadev Bhattiprolu #include <linux/pid_namespace.h>
591f21782eSAdrian Bunk #include <linux/device.h>
6073c27992SEric W. Biederman #include <linux/kthread.h>
61e6fe6649SAdrian Bunk #include <linux/sched.h>
62a1c9eea9SAdrian Bunk #include <linux/signal.h>
63199f0ca5SAkinobu Mita #include <linux/idr.h>
6468bf21aaSSteven Rostedt #include <linux/ftrace.h>
651da177e4SLinus Torvalds 
661da177e4SLinus Torvalds #include <asm/io.h>
671da177e4SLinus Torvalds #include <asm/bugs.h>
681da177e4SLinus Torvalds #include <asm/setup.h>
69a940199fSAndi Kleen #include <asm/sections.h>
7037b73c82SArjan van de Ven #include <asm/cacheflush.h>
711da177e4SLinus Torvalds 
721da177e4SLinus Torvalds #ifdef CONFIG_X86_LOCAL_APIC
731da177e4SLinus Torvalds #include <asm/smp.h>
741da177e4SLinus Torvalds #endif
751da177e4SLinus Torvalds 
761da177e4SLinus Torvalds /*
7769c99ac1SCoywolf Qi Hunt  * This is one of the first .c files built. Error out early if we have compiler
7869c99ac1SCoywolf Qi Hunt  * trouble.
791da177e4SLinus Torvalds  */
801da177e4SLinus Torvalds 
81f1a60dbfSAndrew Morton #if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
82f1a60dbfSAndrew Morton #warning gcc-4.1.0 is known to miscompile the kernel.  A different compiler version is recommended.
83f1a60dbfSAndrew Morton #endif
84f1a60dbfSAndrew Morton 
85aae5f662SSam Ravnborg static int kernel_init(void *);
861da177e4SLinus Torvalds 
871da177e4SLinus Torvalds extern void init_IRQ(void);
881da177e4SLinus Torvalds extern void fork_init(unsigned long);
891da177e4SLinus Torvalds extern void mca_init(void);
901da177e4SLinus Torvalds extern void sbus_init(void);
911da177e4SLinus Torvalds extern void prio_tree_init(void);
921da177e4SLinus Torvalds extern void radix_tree_init(void);
931da177e4SLinus Torvalds extern void free_initmem(void);
941da177e4SLinus Torvalds #ifdef	CONFIG_ACPI
951da177e4SLinus Torvalds extern void acpi_early_init(void);
961da177e4SLinus Torvalds #else
971da177e4SLinus Torvalds static inline void acpi_early_init(void) { }
981da177e4SLinus Torvalds #endif
9937b73c82SArjan van de Ven #ifndef CONFIG_DEBUG_RODATA
10037b73c82SArjan van de Ven static inline void mark_rodata_ro(void) { }
10137b73c82SArjan van de Ven #endif
1021da177e4SLinus Torvalds 
1031da177e4SLinus Torvalds #ifdef CONFIG_TC
1041da177e4SLinus Torvalds extern void tc_init(void);
1051da177e4SLinus Torvalds #endif
1061da177e4SLinus Torvalds 
1071da177e4SLinus Torvalds enum system_states system_state;
1081da177e4SLinus Torvalds EXPORT_SYMBOL(system_state);
1091da177e4SLinus Torvalds 
1101da177e4SLinus Torvalds /*
1111da177e4SLinus Torvalds  * Boot command-line arguments
1121da177e4SLinus Torvalds  */
1131da177e4SLinus Torvalds #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
1141da177e4SLinus Torvalds #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
1151da177e4SLinus Torvalds 
1161da177e4SLinus Torvalds extern void time_init(void);
1171da177e4SLinus Torvalds /* Default late time init is NULL. archs can override this later. */
1181da177e4SLinus Torvalds void (*late_time_init)(void);
1191da177e4SLinus Torvalds extern void softirq_init(void);
1201da177e4SLinus Torvalds 
12130d7e0d4SAlon Bar-Lev /* Untouched command line saved by arch-specific code. */
12230d7e0d4SAlon Bar-Lev char __initdata boot_command_line[COMMAND_LINE_SIZE];
12330d7e0d4SAlon Bar-Lev /* Untouched saved command line (eg. for /proc) */
12430d7e0d4SAlon Bar-Lev char *saved_command_line;
12530d7e0d4SAlon Bar-Lev /* Command line for parameter parsing */
12630d7e0d4SAlon Bar-Lev static char *static_command_line;
1271da177e4SLinus Torvalds 
1281da177e4SLinus Torvalds static char *execute_command;
129ffdfc409SOlof Johansson static char *ramdisk_execute_command;
1301da177e4SLinus Torvalds 
1318b3b2955SJan Beulich #ifdef CONFIG_SMP
1321da177e4SLinus Torvalds /* Setup configured maximum number of CPUs to activate */
133ca74a6f8SAndi Kleen unsigned int __initdata setup_max_cpus = NR_CPUS;
1347e96287dSVivek Goyal 
1357e96287dSVivek Goyal /*
1361da177e4SLinus Torvalds  * Setup routine for controlling SMP activation
1371da177e4SLinus Torvalds  *
1381da177e4SLinus Torvalds  * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
1391da177e4SLinus Torvalds  * activation entirely (the MPS table probe still happens, though).
1401da177e4SLinus Torvalds  *
1411da177e4SLinus Torvalds  * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
1421da177e4SLinus Torvalds  * greater than 0, limits the maximum number of CPUs activated in
1431da177e4SLinus Torvalds  * SMP mode to <NUM>.
1441da177e4SLinus Torvalds  */
14561ec7567SLen Brown #ifndef CONFIG_X86_IO_APIC
14661ec7567SLen Brown static inline void disable_ioapic_setup(void) {};
14761ec7567SLen Brown #endif
14861ec7567SLen Brown 
1491da177e4SLinus Torvalds static int __init nosmp(char *str)
1501da177e4SLinus Torvalds {
151ca74a6f8SAndi Kleen 	setup_max_cpus = 0;
15261ec7567SLen Brown 	disable_ioapic_setup();
1538b3b2955SJan Beulich 	return 0;
1541da177e4SLinus Torvalds }
1551da177e4SLinus Torvalds 
1568b3b2955SJan Beulich early_param("nosmp", nosmp);
1571da177e4SLinus Torvalds 
1581da177e4SLinus Torvalds static int __init maxcpus(char *str)
1591da177e4SLinus Torvalds {
160ca74a6f8SAndi Kleen 	get_option(&str, &setup_max_cpus);
161ca74a6f8SAndi Kleen 	if (setup_max_cpus == 0)
16261ec7567SLen Brown 		disable_ioapic_setup();
16361ec7567SLen Brown 
16461ec7567SLen Brown 	return 0;
1651da177e4SLinus Torvalds }
1661da177e4SLinus Torvalds 
16781340977SHugh Dickins early_param("maxcpus", maxcpus);
1688b3b2955SJan Beulich #else
169ca74a6f8SAndi Kleen #define setup_max_cpus NR_CPUS
1708b3b2955SJan Beulich #endif
1718b3b2955SJan Beulich 
1728b3b2955SJan Beulich /*
1738b3b2955SJan Beulich  * If set, this is an indication to the drivers that reset the underlying
1748b3b2955SJan Beulich  * device before going ahead with the initialization otherwise driver might
1758b3b2955SJan Beulich  * rely on the BIOS and skip the reset operation.
1768b3b2955SJan Beulich  *
1778b3b2955SJan Beulich  * This is useful if kernel is booting in an unreliable environment.
1788b3b2955SJan Beulich  * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
1798b3b2955SJan Beulich  * skipped and devices will be in unknown state.
1808b3b2955SJan Beulich  */
1818b3b2955SJan Beulich unsigned int reset_devices;
1828b3b2955SJan Beulich EXPORT_SYMBOL(reset_devices);
1831da177e4SLinus Torvalds 
1847e96287dSVivek Goyal static int __init set_reset_devices(char *str)
1857e96287dSVivek Goyal {
1867e96287dSVivek Goyal 	reset_devices = 1;
1877e96287dSVivek Goyal 	return 1;
1887e96287dSVivek Goyal }
1897e96287dSVivek Goyal 
1907e96287dSVivek Goyal __setup("reset_devices", set_reset_devices);
1917e96287dSVivek Goyal 
1921da177e4SLinus Torvalds static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
1931da177e4SLinus Torvalds char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
1941da177e4SLinus Torvalds static const char *panic_later, *panic_param;
1951da177e4SLinus Torvalds 
1961da177e4SLinus Torvalds extern struct obs_kernel_param __setup_start[], __setup_end[];
1971da177e4SLinus Torvalds 
1981da177e4SLinus Torvalds static int __init obsolete_checksetup(char *line)
1991da177e4SLinus Torvalds {
2001da177e4SLinus Torvalds 	struct obs_kernel_param *p;
20133df0d19SRusty Russell 	int had_early_param = 0;
2021da177e4SLinus Torvalds 
2031da177e4SLinus Torvalds 	p = __setup_start;
2041da177e4SLinus Torvalds 	do {
2051da177e4SLinus Torvalds 		int n = strlen(p->str);
2061da177e4SLinus Torvalds 		if (!strncmp(line, p->str, n)) {
2071da177e4SLinus Torvalds 			if (p->early) {
20833df0d19SRusty Russell 				/* Already done in parse_early_param?
20933df0d19SRusty Russell 				 * (Needs exact match on param part).
21033df0d19SRusty Russell 				 * Keep iterating, as we can have early
21133df0d19SRusty Russell 				 * params and __setups of same names 8( */
2121da177e4SLinus Torvalds 				if (line[n] == '\0' || line[n] == '=')
21333df0d19SRusty Russell 					had_early_param = 1;
2141da177e4SLinus Torvalds 			} else if (!p->setup_func) {
2151da177e4SLinus Torvalds 				printk(KERN_WARNING "Parameter %s is obsolete,"
2161da177e4SLinus Torvalds 				       " ignored\n", p->str);
2171da177e4SLinus Torvalds 				return 1;
2181da177e4SLinus Torvalds 			} else if (p->setup_func(line + n))
2191da177e4SLinus Torvalds 				return 1;
2201da177e4SLinus Torvalds 		}
2211da177e4SLinus Torvalds 		p++;
2221da177e4SLinus Torvalds 	} while (p < __setup_end);
22333df0d19SRusty Russell 
22433df0d19SRusty Russell 	return had_early_param;
2251da177e4SLinus Torvalds }
2261da177e4SLinus Torvalds 
2271da177e4SLinus Torvalds /*
2281da177e4SLinus Torvalds  * This should be approx 2 Bo*oMips to start (note initial shift), and will
2291da177e4SLinus Torvalds  * still work even if initially too large, it will just take slightly longer
2301da177e4SLinus Torvalds  */
2311da177e4SLinus Torvalds unsigned long loops_per_jiffy = (1<<12);
2321da177e4SLinus Torvalds 
2331da177e4SLinus Torvalds EXPORT_SYMBOL(loops_per_jiffy);
2341da177e4SLinus Torvalds 
2351da177e4SLinus Torvalds static int __init debug_kernel(char *str)
2361da177e4SLinus Torvalds {
2371da177e4SLinus Torvalds 	console_loglevel = 10;
238f6f21c81SYinghai Lu 	return 0;
2391da177e4SLinus Torvalds }
2401da177e4SLinus Torvalds 
2411da177e4SLinus Torvalds static int __init quiet_kernel(char *str)
2421da177e4SLinus Torvalds {
2431da177e4SLinus Torvalds 	console_loglevel = 4;
244f6f21c81SYinghai Lu 	return 0;
2451da177e4SLinus Torvalds }
2461da177e4SLinus Torvalds 
247f6f21c81SYinghai Lu early_param("debug", debug_kernel);
248f6f21c81SYinghai Lu early_param("quiet", quiet_kernel);
2491da177e4SLinus Torvalds 
2501da177e4SLinus Torvalds static int __init loglevel(char *str)
2511da177e4SLinus Torvalds {
2521da177e4SLinus Torvalds 	get_option(&str, &console_loglevel);
253d9d4fcfeSAlex Riesen 	return 0;
2541da177e4SLinus Torvalds }
2551da177e4SLinus Torvalds 
256f6f21c81SYinghai Lu early_param("loglevel", loglevel);
2571da177e4SLinus Torvalds 
2581da177e4SLinus Torvalds /*
2591da177e4SLinus Torvalds  * Unknown boot options get handed to init, unless they look like
2601da177e4SLinus Torvalds  * failed parameters
2611da177e4SLinus Torvalds  */
2621da177e4SLinus Torvalds static int __init unknown_bootoption(char *param, char *val)
2631da177e4SLinus Torvalds {
2641da177e4SLinus Torvalds 	/* Change NUL term back to "=", to make "param" the whole string. */
2651da177e4SLinus Torvalds 	if (val) {
2661da177e4SLinus Torvalds 		/* param=val or param="val"? */
2671da177e4SLinus Torvalds 		if (val == param+strlen(param)+1)
2681da177e4SLinus Torvalds 			val[-1] = '=';
2691da177e4SLinus Torvalds 		else if (val == param+strlen(param)+2) {
2701da177e4SLinus Torvalds 			val[-2] = '=';
2711da177e4SLinus Torvalds 			memmove(val-1, val, strlen(val)+1);
2721da177e4SLinus Torvalds 			val--;
2731da177e4SLinus Torvalds 		} else
2741da177e4SLinus Torvalds 			BUG();
2751da177e4SLinus Torvalds 	}
2761da177e4SLinus Torvalds 
2771da177e4SLinus Torvalds 	/* Handle obsolete-style parameters */
2781da177e4SLinus Torvalds 	if (obsolete_checksetup(param))
2791da177e4SLinus Torvalds 		return 0;
2801da177e4SLinus Torvalds 
2811da177e4SLinus Torvalds 	/*
282211fee8aSSimon Arlott 	 * Preemptive maintenance for "why didn't my misspelled command
2831da177e4SLinus Torvalds 	 * line work?"
2841da177e4SLinus Torvalds 	 */
2851da177e4SLinus Torvalds 	if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
2861da177e4SLinus Torvalds 		printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
2871da177e4SLinus Torvalds 		return 0;
2881da177e4SLinus Torvalds 	}
2891da177e4SLinus Torvalds 
2901da177e4SLinus Torvalds 	if (panic_later)
2911da177e4SLinus Torvalds 		return 0;
2921da177e4SLinus Torvalds 
2931da177e4SLinus Torvalds 	if (val) {
2941da177e4SLinus Torvalds 		/* Environment option */
2951da177e4SLinus Torvalds 		unsigned int i;
2961da177e4SLinus Torvalds 		for (i = 0; envp_init[i]; i++) {
2971da177e4SLinus Torvalds 			if (i == MAX_INIT_ENVS) {
2981da177e4SLinus Torvalds 				panic_later = "Too many boot env vars at `%s'";
2991da177e4SLinus Torvalds 				panic_param = param;
3001da177e4SLinus Torvalds 			}
3011da177e4SLinus Torvalds 			if (!strncmp(param, envp_init[i], val - param))
3021da177e4SLinus Torvalds 				break;
3031da177e4SLinus Torvalds 		}
3041da177e4SLinus Torvalds 		envp_init[i] = param;
3051da177e4SLinus Torvalds 	} else {
3061da177e4SLinus Torvalds 		/* Command line option */
3071da177e4SLinus Torvalds 		unsigned int i;
3081da177e4SLinus Torvalds 		for (i = 0; argv_init[i]; i++) {
3091da177e4SLinus Torvalds 			if (i == MAX_INIT_ARGS) {
3101da177e4SLinus Torvalds 				panic_later = "Too many boot init vars at `%s'";
3111da177e4SLinus Torvalds 				panic_param = param;
3121da177e4SLinus Torvalds 			}
3131da177e4SLinus Torvalds 		}
3141da177e4SLinus Torvalds 		argv_init[i] = param;
3151da177e4SLinus Torvalds 	}
3161da177e4SLinus Torvalds 	return 0;
3171da177e4SLinus Torvalds }
3181da177e4SLinus Torvalds 
31912d6f21eSIngo Molnar #ifdef CONFIG_DEBUG_PAGEALLOC
32012d6f21eSIngo Molnar int __read_mostly debug_pagealloc_enabled = 0;
32112d6f21eSIngo Molnar #endif
32212d6f21eSIngo Molnar 
3231da177e4SLinus Torvalds static int __init init_setup(char *str)
3241da177e4SLinus Torvalds {
3251da177e4SLinus Torvalds 	unsigned int i;
3261da177e4SLinus Torvalds 
3271da177e4SLinus Torvalds 	execute_command = str;
3281da177e4SLinus Torvalds 	/*
3291da177e4SLinus Torvalds 	 * In case LILO is going to boot us with default command line,
3301da177e4SLinus Torvalds 	 * it prepends "auto" before the whole cmdline which makes
3311da177e4SLinus Torvalds 	 * the shell think it should execute a script with such name.
3321da177e4SLinus Torvalds 	 * So we ignore all arguments entered _before_ init=... [MJ]
3331da177e4SLinus Torvalds 	 */
3341da177e4SLinus Torvalds 	for (i = 1; i < MAX_INIT_ARGS; i++)
3351da177e4SLinus Torvalds 		argv_init[i] = NULL;
3361da177e4SLinus Torvalds 	return 1;
3371da177e4SLinus Torvalds }
3381da177e4SLinus Torvalds __setup("init=", init_setup);
3391da177e4SLinus Torvalds 
340ffdfc409SOlof Johansson static int __init rdinit_setup(char *str)
341ffdfc409SOlof Johansson {
342ffdfc409SOlof Johansson 	unsigned int i;
343ffdfc409SOlof Johansson 
344ffdfc409SOlof Johansson 	ramdisk_execute_command = str;
345ffdfc409SOlof Johansson 	/* See "auto" comment in init_setup */
346ffdfc409SOlof Johansson 	for (i = 1; i < MAX_INIT_ARGS; i++)
347ffdfc409SOlof Johansson 		argv_init[i] = NULL;
348ffdfc409SOlof Johansson 	return 1;
349ffdfc409SOlof Johansson }
350ffdfc409SOlof Johansson __setup("rdinit=", rdinit_setup);
351ffdfc409SOlof Johansson 
3521da177e4SLinus Torvalds #ifndef CONFIG_SMP
3531da177e4SLinus Torvalds 
3541da177e4SLinus Torvalds #ifdef CONFIG_X86_LOCAL_APIC
3551da177e4SLinus Torvalds static void __init smp_init(void)
3561da177e4SLinus Torvalds {
3571da177e4SLinus Torvalds 	APIC_init_uniprocessor();
3581da177e4SLinus Torvalds }
3591da177e4SLinus Torvalds #else
3601da177e4SLinus Torvalds #define smp_init()	do { } while (0)
3611da177e4SLinus Torvalds #endif
3621da177e4SLinus Torvalds 
3631da177e4SLinus Torvalds static inline void setup_per_cpu_areas(void) { }
364e0982e90SMike Travis static inline void setup_nr_cpu_ids(void) { }
3651da177e4SLinus Torvalds static inline void smp_prepare_cpus(unsigned int maxcpus) { }
3661da177e4SLinus Torvalds 
3671da177e4SLinus Torvalds #else
3681da177e4SLinus Torvalds 
369321a8e9dSMike Travis #if NR_CPUS > BITS_PER_LONG
370321a8e9dSMike Travis cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
371321a8e9dSMike Travis EXPORT_SYMBOL(cpu_mask_all);
372321a8e9dSMike Travis #endif
373321a8e9dSMike Travis 
374e0982e90SMike Travis /* Setup number of possible processor ids */
375e0982e90SMike Travis int nr_cpu_ids __read_mostly = NR_CPUS;
376e0982e90SMike Travis EXPORT_SYMBOL(nr_cpu_ids);
377e0982e90SMike Travis 
378e0982e90SMike Travis /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
379e0982e90SMike Travis static void __init setup_nr_cpu_ids(void)
380e0982e90SMike Travis {
381e0982e90SMike Travis 	int cpu, highest_cpu = 0;
382e0982e90SMike Travis 
383e0982e90SMike Travis 	for_each_possible_cpu(cpu)
384e0982e90SMike Travis 		highest_cpu = cpu;
385e0982e90SMike Travis 
386e0982e90SMike Travis 	nr_cpu_ids = highest_cpu + 1;
387e0982e90SMike Travis }
388e0982e90SMike Travis 
389dd5af90aSMike Travis #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
390b73b459fSEric Dumazet unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
3911da177e4SLinus Torvalds 
3921da177e4SLinus Torvalds EXPORT_SYMBOL(__per_cpu_offset);
3931da177e4SLinus Torvalds 
3941da177e4SLinus Torvalds static void __init setup_per_cpu_areas(void)
3951da177e4SLinus Torvalds {
3961da177e4SLinus Torvalds 	unsigned long size, i;
3971da177e4SLinus Torvalds 	char *ptr;
39863872f87SEric Dumazet 	unsigned long nr_possible_cpus = num_possible_cpus();
3991da177e4SLinus Torvalds 
4001da177e4SLinus Torvalds 	/* Copy section for each CPU (we discard the original) */
401b6e3590fSJeremy Fitzhardinge 	size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
402b6e3590fSJeremy Fitzhardinge 	ptr = alloc_bootmem_pages(size * nr_possible_cpus);
4031da177e4SLinus Torvalds 
4040a945022SKAMEZAWA Hiroyuki 	for_each_possible_cpu(i) {
4051da177e4SLinus Torvalds 		__per_cpu_offset[i] = ptr - __per_cpu_start;
4061da177e4SLinus Torvalds 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
40763872f87SEric Dumazet 		ptr += size;
4081da177e4SLinus Torvalds 	}
4091da177e4SLinus Torvalds }
410dd5af90aSMike Travis #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
4111da177e4SLinus Torvalds 
4121da177e4SLinus Torvalds /* Called by boot processor to activate the rest. */
4131da177e4SLinus Torvalds static void __init smp_init(void)
4141da177e4SLinus Torvalds {
41553b8a315SChristoph Lameter 	unsigned int cpu;
4161da177e4SLinus Torvalds 
417e761b772SMax Krasnyansky 	/*
418e761b772SMax Krasnyansky 	 * Set up the current CPU as possible to migrate to.
419e761b772SMax Krasnyansky 	 * The other ones will be done by cpu_up/cpu_down()
420e761b772SMax Krasnyansky 	 */
421e761b772SMax Krasnyansky 	cpu = smp_processor_id();
422e761b772SMax Krasnyansky 	cpu_set(cpu, cpu_active_map);
423e761b772SMax Krasnyansky 
4241da177e4SLinus Torvalds 	/* FIXME: This should be done in userspace --RR */
42553b8a315SChristoph Lameter 	for_each_present_cpu(cpu) {
426ca74a6f8SAndi Kleen 		if (num_online_cpus() >= setup_max_cpus)
4271da177e4SLinus Torvalds 			break;
42853b8a315SChristoph Lameter 		if (!cpu_online(cpu))
42953b8a315SChristoph Lameter 			cpu_up(cpu);
4301da177e4SLinus Torvalds 	}
4311da177e4SLinus Torvalds 
4321da177e4SLinus Torvalds 	/* Any cleanup work */
4331da177e4SLinus Torvalds 	printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
434ca74a6f8SAndi Kleen 	smp_cpus_done(setup_max_cpus);
4351da177e4SLinus Torvalds }
4361da177e4SLinus Torvalds 
4371da177e4SLinus Torvalds #endif
4381da177e4SLinus Torvalds 
4391da177e4SLinus Torvalds /*
44030d7e0d4SAlon Bar-Lev  * We need to store the untouched command line for future reference.
44130d7e0d4SAlon Bar-Lev  * We also need to store the touched command line since the parameter
44230d7e0d4SAlon Bar-Lev  * parsing is performed in place, and we should allow a component to
44330d7e0d4SAlon Bar-Lev  * store reference of name/value for future reference.
44430d7e0d4SAlon Bar-Lev  */
44530d7e0d4SAlon Bar-Lev static void __init setup_command_line(char *command_line)
44630d7e0d4SAlon Bar-Lev {
44730d7e0d4SAlon Bar-Lev 	saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
44830d7e0d4SAlon Bar-Lev 	static_command_line = alloc_bootmem(strlen (command_line)+1);
44930d7e0d4SAlon Bar-Lev 	strcpy (saved_command_line, boot_command_line);
45030d7e0d4SAlon Bar-Lev 	strcpy (static_command_line, command_line);
45130d7e0d4SAlon Bar-Lev }
45230d7e0d4SAlon Bar-Lev 
45330d7e0d4SAlon Bar-Lev /*
4541da177e4SLinus Torvalds  * We need to finalize in a non-__init function or else race conditions
4551da177e4SLinus Torvalds  * between the root thread and the init thread may cause start_kernel to
4561da177e4SLinus Torvalds  * be reaped by free_initmem before the root thread has proceeded to
4571da177e4SLinus Torvalds  * cpu_idle.
4581da177e4SLinus Torvalds  *
4591da177e4SLinus Torvalds  * gcc-3.4 accidentally inlines this function, so use noinline.
4601da177e4SLinus Torvalds  */
4611da177e4SLinus Torvalds 
46292080309SSam Ravnborg static void noinline __init_refok rest_init(void)
4631da177e4SLinus Torvalds 	__releases(kernel_lock)
4641da177e4SLinus Torvalds {
46573c27992SEric W. Biederman 	int pid;
46673c27992SEric W. Biederman 
467aae5f662SSam Ravnborg 	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
4681da177e4SLinus Torvalds 	numa_default_policy();
46973c27992SEric W. Biederman 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
4705cd20455SPavel Emelyanov 	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
4711da177e4SLinus Torvalds 	unlock_kernel();
472f340c0d1SIngo Molnar 
473f340c0d1SIngo Molnar 	/*
474f340c0d1SIngo Molnar 	 * The boot idle thread must execute schedule()
4751df21055SIngo Molnar 	 * at least once to get things moving:
476f340c0d1SIngo Molnar 	 */
4771df21055SIngo Molnar 	init_idle_bootup_task(current);
4785bfb5d69SNick Piggin 	preempt_enable_no_resched();
479f340c0d1SIngo Molnar 	schedule();
4805bfb5d69SNick Piggin 	preempt_disable();
481f340c0d1SIngo Molnar 
4825bfb5d69SNick Piggin 	/* Call into cpu_idle with preempt disabled */
4831da177e4SLinus Torvalds 	cpu_idle();
4841da177e4SLinus Torvalds }
4851da177e4SLinus Torvalds 
4861da177e4SLinus Torvalds /* Check for early params. */
4871da177e4SLinus Torvalds static int __init do_early_param(char *param, char *val)
4881da177e4SLinus Torvalds {
4891da177e4SLinus Torvalds 	struct obs_kernel_param *p;
4901da177e4SLinus Torvalds 
4911da177e4SLinus Torvalds 	for (p = __setup_start; p < __setup_end; p++) {
49218a8bd94SYinghai Lu 		if ((p->early && strcmp(param, p->str) == 0) ||
49318a8bd94SYinghai Lu 		    (strcmp(param, "console") == 0 &&
49418a8bd94SYinghai Lu 		     strcmp(p->str, "earlycon") == 0)
49518a8bd94SYinghai Lu 		) {
4961da177e4SLinus Torvalds 			if (p->setup_func(val) != 0)
4971da177e4SLinus Torvalds 				printk(KERN_WARNING
4981da177e4SLinus Torvalds 				       "Malformed early option '%s'\n", param);
4991da177e4SLinus Torvalds 		}
5001da177e4SLinus Torvalds 	}
5011da177e4SLinus Torvalds 	/* We accept everything at this stage. */
5021da177e4SLinus Torvalds 	return 0;
5031da177e4SLinus Torvalds }
5041da177e4SLinus Torvalds 
5051da177e4SLinus Torvalds /* Arch code calls this early on, or if not, just before other parsing. */
5061da177e4SLinus Torvalds void __init parse_early_param(void)
5071da177e4SLinus Torvalds {
5081da177e4SLinus Torvalds 	static __initdata int done = 0;
5091da177e4SLinus Torvalds 	static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
5101da177e4SLinus Torvalds 
5111da177e4SLinus Torvalds 	if (done)
5121da177e4SLinus Torvalds 		return;
5131da177e4SLinus Torvalds 
5141da177e4SLinus Torvalds 	/* All fall through to do_early_param. */
51530d7e0d4SAlon Bar-Lev 	strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
5161da177e4SLinus Torvalds 	parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
5171da177e4SLinus Torvalds 	done = 1;
5181da177e4SLinus Torvalds }
5191da177e4SLinus Torvalds 
5201da177e4SLinus Torvalds /*
5211da177e4SLinus Torvalds  *	Activate the first processor.
5221da177e4SLinus Torvalds  */
5231da177e4SLinus Torvalds 
52444fd2299SStas Sergeev static void __init boot_cpu_init(void)
52544fd2299SStas Sergeev {
52644fd2299SStas Sergeev 	int cpu = smp_processor_id();
52744fd2299SStas Sergeev 	/* Mark the boot cpu "present", "online" etc for SMP and UP case */
52844fd2299SStas Sergeev 	cpu_set(cpu, cpu_online_map);
52944fd2299SStas Sergeev 	cpu_set(cpu, cpu_present_map);
53044fd2299SStas Sergeev 	cpu_set(cpu, cpu_possible_map);
53144fd2299SStas Sergeev }
53244fd2299SStas Sergeev 
533839ad62eSBenjamin Herrenschmidt void __init __weak smp_setup_processor_id(void)
534033ab7f8SAndrew Morton {
535033ab7f8SAndrew Morton }
536033ab7f8SAndrew Morton 
5378c9843e5SBenjamin Herrenschmidt void __init __weak thread_info_cache_init(void)
5388c9843e5SBenjamin Herrenschmidt {
5398c9843e5SBenjamin Herrenschmidt }
5408c9843e5SBenjamin Herrenschmidt 
5411da177e4SLinus Torvalds asmlinkage void __init start_kernel(void)
5421da177e4SLinus Torvalds {
5431da177e4SLinus Torvalds 	char * command_line;
5441da177e4SLinus Torvalds 	extern struct kernel_param __start___param[], __stop___param[];
545033ab7f8SAndrew Morton 
546033ab7f8SAndrew Morton 	smp_setup_processor_id();
547033ab7f8SAndrew Morton 
5481da177e4SLinus Torvalds 	/*
549fbb9ce95SIngo Molnar 	 * Need to run as early as possible, to initialize the
550fbb9ce95SIngo Molnar 	 * lockdep hash:
551fbb9ce95SIngo Molnar 	 */
552c9538ed4SAndi Kleen 	unwind_init();
553fbb9ce95SIngo Molnar 	lockdep_init();
5543ac7fe5aSThomas Gleixner 	debug_objects_early_init();
555ddbcc7e8SPaul Menage 	cgroup_init_early();
556fbb9ce95SIngo Molnar 
557fbb9ce95SIngo Molnar 	local_irq_disable();
558fbb9ce95SIngo Molnar 	early_boot_irqs_off();
559243c7621SIngo Molnar 	early_init_irq_lock_class();
560fbb9ce95SIngo Molnar 
561fbb9ce95SIngo Molnar /*
5621da177e4SLinus Torvalds  * Interrupts are still disabled. Do necessary setups, then
5631da177e4SLinus Torvalds  * enable them
5641da177e4SLinus Torvalds  */
5651da177e4SLinus Torvalds 	lock_kernel();
566906568c9SThomas Gleixner 	tick_init();
56744fd2299SStas Sergeev 	boot_cpu_init();
5681da177e4SLinus Torvalds 	page_address_init();
5691da177e4SLinus Torvalds 	printk(KERN_NOTICE);
5708993780aSLinus Torvalds 	printk(linux_banner);
5711da177e4SLinus Torvalds 	setup_arch(&command_line);
572cf475ad2SBalbir Singh 	mm_init_owner(&init_mm, &init_task);
57330d7e0d4SAlon Bar-Lev 	setup_command_line(command_line);
574690a973fSJan Beulich 	unwind_setup();
5751da177e4SLinus Torvalds 	setup_per_cpu_areas();
576e0982e90SMike Travis 	setup_nr_cpu_ids();
57744fd2299SStas Sergeev 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
5781da177e4SLinus Torvalds 
5791da177e4SLinus Torvalds 	/*
5801da177e4SLinus Torvalds 	 * Set up the scheduler prior starting any interrupts (such as the
5811da177e4SLinus Torvalds 	 * timer interrupt). Full topology setup happens at smp_init()
5821da177e4SLinus Torvalds 	 * time - but meanwhile we still have a functioning scheduler.
5831da177e4SLinus Torvalds 	 */
5841da177e4SLinus Torvalds 	sched_init();
5851da177e4SLinus Torvalds 	/*
5861da177e4SLinus Torvalds 	 * Disable preemption - early bootup scheduling is extremely
5871da177e4SLinus Torvalds 	 * fragile until we cpu_idle() for the first time.
5881da177e4SLinus Torvalds 	 */
5891da177e4SLinus Torvalds 	preempt_disable();
5901da177e4SLinus Torvalds 	build_all_zonelists();
5911da177e4SLinus Torvalds 	page_alloc_init();
59230d7e0d4SAlon Bar-Lev 	printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
5931da177e4SLinus Torvalds 	parse_early_param();
59430d7e0d4SAlon Bar-Lev 	parse_args("Booting kernel", static_command_line, __start___param,
5951da177e4SLinus Torvalds 		   __stop___param - __start___param,
5961da177e4SLinus Torvalds 		   &unknown_bootoption);
597c4a68306SArd van Breemen 	if (!irqs_disabled()) {
598c4a68306SArd van Breemen 		printk(KERN_WARNING "start_kernel(): bug: interrupts were "
599c4a68306SArd van Breemen 				"enabled *very* early, fixing it\n");
600c4a68306SArd van Breemen 		local_irq_disable();
601c4a68306SArd van Breemen 	}
6021da177e4SLinus Torvalds 	sort_main_extable();
6031da177e4SLinus Torvalds 	trap_init();
6041da177e4SLinus Torvalds 	rcu_init();
6051da177e4SLinus Torvalds 	init_IRQ();
6061da177e4SLinus Torvalds 	pidhash_init();
6071da177e4SLinus Torvalds 	init_timers();
608c0a31329SThomas Gleixner 	hrtimers_init();
6091da177e4SLinus Torvalds 	softirq_init();
610ad596171Sjohn stultz 	timekeeping_init();
61188fecaa2Sjohn stultz 	time_init();
6123e51f33fSPeter Zijlstra 	sched_clock_init();
61393e02814SHeiko Carstens 	profile_init();
61493e02814SHeiko Carstens 	if (!irqs_disabled())
61593e02814SHeiko Carstens 		printk("start_kernel(): bug: interrupts were enabled early\n");
616fbb9ce95SIngo Molnar 	early_boot_irqs_on();
61793e02814SHeiko Carstens 	local_irq_enable();
6181da177e4SLinus Torvalds 
6191da177e4SLinus Torvalds 	/*
6201da177e4SLinus Torvalds 	 * HACK ALERT! This is early. We're enabling the console before
6211da177e4SLinus Torvalds 	 * we've done PCI setups etc, and console_init() must be aware of
6221da177e4SLinus Torvalds 	 * this. But we do want output early, in case something goes wrong.
6231da177e4SLinus Torvalds 	 */
6241da177e4SLinus Torvalds 	console_init();
6251da177e4SLinus Torvalds 	if (panic_later)
6261da177e4SLinus Torvalds 		panic(panic_later, panic_param);
627fbb9ce95SIngo Molnar 
628fbb9ce95SIngo Molnar 	lockdep_info();
629fbb9ce95SIngo Molnar 
6309a11b49aSIngo Molnar 	/*
6319a11b49aSIngo Molnar 	 * Need to run this when irqs are enabled, because it wants
6329a11b49aSIngo Molnar 	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
6339a11b49aSIngo Molnar 	 * too:
6349a11b49aSIngo Molnar 	 */
6359a11b49aSIngo Molnar 	locking_selftest();
6369a11b49aSIngo Molnar 
6371da177e4SLinus Torvalds #ifdef CONFIG_BLK_DEV_INITRD
6381da177e4SLinus Torvalds 	if (initrd_start && !initrd_below_start_ok &&
639bd673c7cSGeert Uytterhoeven 	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
6401da177e4SLinus Torvalds 		printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
641fb6624ebSGeert Uytterhoeven 		    "disabling it.\n",
642bd673c7cSGeert Uytterhoeven 		    page_to_pfn(virt_to_page((void *)initrd_start)),
643bd673c7cSGeert Uytterhoeven 		    min_low_pfn);
6441da177e4SLinus Torvalds 		initrd_start = 0;
6451da177e4SLinus Torvalds 	}
6461da177e4SLinus Torvalds #endif
647db64fe02SNick Piggin 	vmalloc_init();
6481da177e4SLinus Torvalds 	vfs_caches_init_early();
649c417f024SPaul Jackson 	cpuset_init_early();
6501da177e4SLinus Torvalds 	mem_init();
651a03c2a48SThomas Gleixner 	enable_debug_pagealloc();
652d221938cSGautham R Shenoy 	cpu_hotplug_init();
6531da177e4SLinus Torvalds 	kmem_cache_init();
6543ac7fe5aSThomas Gleixner 	debug_objects_mem_init();
655199f0ca5SAkinobu Mita 	idr_init_cache();
656e7c8d5c9SChristoph Lameter 	setup_per_cpu_pageset();
6571da177e4SLinus Torvalds 	numa_policy_init();
6581da177e4SLinus Torvalds 	if (late_time_init)
6591da177e4SLinus Torvalds 		late_time_init();
6601da177e4SLinus Torvalds 	calibrate_delay();
6611da177e4SLinus Torvalds 	pidmap_init();
6621da177e4SLinus Torvalds 	pgtable_cache_init();
6631da177e4SLinus Torvalds 	prio_tree_init();
6641da177e4SLinus Torvalds 	anon_vma_init();
6651da177e4SLinus Torvalds #ifdef CONFIG_X86
6661da177e4SLinus Torvalds 	if (efi_enabled)
6671da177e4SLinus Torvalds 		efi_enter_virtual_mode();
6681da177e4SLinus Torvalds #endif
6698c9843e5SBenjamin Herrenschmidt 	thread_info_cache_init();
6701da177e4SLinus Torvalds 	fork_init(num_physpages);
6711da177e4SLinus Torvalds 	proc_caches_init();
6721da177e4SLinus Torvalds 	buffer_init();
6731da177e4SLinus Torvalds 	unnamed_dev_init();
6741da177e4SLinus Torvalds 	key_init();
6751da177e4SLinus Torvalds 	security_init();
6761da177e4SLinus Torvalds 	vfs_caches_init(num_physpages);
6771da177e4SLinus Torvalds 	radix_tree_init();
6781da177e4SLinus Torvalds 	signals_init();
6791da177e4SLinus Torvalds 	/* rootfs populating might need page-writeback */
6801da177e4SLinus Torvalds 	page_writeback_init();
6811da177e4SLinus Torvalds #ifdef CONFIG_PROC_FS
6821da177e4SLinus Torvalds 	proc_root_init();
6831da177e4SLinus Torvalds #endif
684ddbcc7e8SPaul Menage 	cgroup_init();
6851da177e4SLinus Torvalds 	cpuset_init();
686c757249aSShailabh Nagar 	taskstats_init_early();
687ca74e92bSShailabh Nagar 	delayacct_init();
6881da177e4SLinus Torvalds 
6891da177e4SLinus Torvalds 	check_bugs();
6901da177e4SLinus Torvalds 
6911da177e4SLinus Torvalds 	acpi_early_init(); /* before LAPIC and SMP init */
6921da177e4SLinus Torvalds 
69368bf21aaSSteven Rostedt 	ftrace_init();
69468bf21aaSSteven Rostedt 
6951da177e4SLinus Torvalds 	/* Do the rest non-__init'ed, we're now alive */
6961da177e4SLinus Torvalds 	rest_init();
6971da177e4SLinus Torvalds }
6981da177e4SLinus Torvalds 
69959f9415fSArjan van de Ven static int initcall_debug;
700*d0ea3d7dSRusty Russell core_param(initcall_debug, initcall_debug, bool, 0644);
7011da177e4SLinus Torvalds 
70259f9415fSArjan van de Ven int do_one_initcall(initcall_t fn)
7031da177e4SLinus Torvalds {
7041da177e4SLinus Torvalds 	int count = preempt_count();
705cb5ab742SFrederic Weisbecker 	ktime_t delta;
706a76bfd0dSCyrill Gorcunov 	char msgbuf[64];
7073bf77af6SFrédéric Weisbecker 	struct boot_trace it;
7081da177e4SLinus Torvalds 
7091da177e4SLinus Torvalds 	if (initcall_debug) {
7103bf77af6SFrédéric Weisbecker 		it.caller = task_pid_nr(current);
7113bf77af6SFrédéric Weisbecker 		printk("calling  %pF @ %i\n", fn, it.caller);
712cb5ab742SFrederic Weisbecker 		it.calltime = ktime_get();
7131da177e4SLinus Torvalds 	}
7141da177e4SLinus Torvalds 
715cb5ab742SFrederic Weisbecker 	it.result = fn();
7161da177e4SLinus Torvalds 
7178f0c45cdSIngo Molnar 	if (initcall_debug) {
718cb5ab742SFrederic Weisbecker 		it.rettime = ktime_get();
719cb5ab742SFrederic Weisbecker 		delta = ktime_sub(it.rettime, it.calltime);
720ca538f6bSTim Bird 		it.duration = (unsigned long long) delta.tv64 >> 10;
721ca538f6bSTim Bird 		printk("initcall %pF returned %d after %Ld usecs\n", fn,
722cb5ab742SFrederic Weisbecker 			it.result, it.duration);
7235601020fSFrederic Weisbecker 		trace_boot(&it, fn);
7248f0c45cdSIngo Molnar 	}
7258f0c45cdSIngo Molnar 
726e662e1cfSCyrill Gorcunov 	msgbuf[0] = 0;
727e662e1cfSCyrill Gorcunov 
728cb5ab742SFrederic Weisbecker 	if (it.result && it.result != -ENODEV && initcall_debug)
729cb5ab742SFrederic Weisbecker 		sprintf(msgbuf, "error code %d ", it.result);
730e662e1cfSCyrill Gorcunov 
7311da177e4SLinus Torvalds 	if (preempt_count() != count) {
732a76bfd0dSCyrill Gorcunov 		strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
7331da177e4SLinus Torvalds 		preempt_count() = count;
7341da177e4SLinus Torvalds 	}
7351da177e4SLinus Torvalds 	if (irqs_disabled()) {
736a76bfd0dSCyrill Gorcunov 		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
7371da177e4SLinus Torvalds 		local_irq_enable();
7381da177e4SLinus Torvalds 	}
739e662e1cfSCyrill Gorcunov 	if (msgbuf[0]) {
74096d746c6SLinus Torvalds 		printk("initcall %pF returned with %s\n", fn, msgbuf);
7411da177e4SLinus Torvalds 	}
74259f9415fSArjan van de Ven 
743cb5ab742SFrederic Weisbecker 	return it.result;
7441da177e4SLinus Torvalds }
7451da177e4SLinus Torvalds 
746e0df154fSLinus Torvalds 
747c2147a50SEduard - Gabriel Munteanu extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
748e0df154fSLinus Torvalds 
749e0df154fSLinus Torvalds static void __init do_initcalls(void)
750e0df154fSLinus Torvalds {
751e0df154fSLinus Torvalds 	initcall_t *call;
752e0df154fSLinus Torvalds 
753c2147a50SEduard - Gabriel Munteanu 	for (call = __early_initcall_end; call < __initcall_end; call++)
754e0df154fSLinus Torvalds 		do_one_initcall(*call);
755e0df154fSLinus Torvalds 
7561da177e4SLinus Torvalds 	/* Make sure there is no pending stuff from the initcall sequence */
7571da177e4SLinus Torvalds 	flush_scheduled_work();
7581da177e4SLinus Torvalds }
7591da177e4SLinus Torvalds 
7601da177e4SLinus Torvalds /*
7611da177e4SLinus Torvalds  * Ok, the machine is now initialized. None of the devices
7621da177e4SLinus Torvalds  * have been touched yet, but the CPU subsystem is up and
7631da177e4SLinus Torvalds  * running, and memory and process management works.
7641da177e4SLinus Torvalds  *
7651da177e4SLinus Torvalds  * Now we can finally start doing some real work..
7661da177e4SLinus Torvalds  */
7671da177e4SLinus Torvalds static void __init do_basic_setup(void)
7681da177e4SLinus Torvalds {
7694446a36fSPaul E. McKenney 	rcu_init_sched(); /* needed by module_init stage. */
7701da177e4SLinus Torvalds 	/* drivers will send hotplug events */
7711da177e4SLinus Torvalds 	init_workqueues();
7721da177e4SLinus Torvalds 	usermodehelper_init();
7731da177e4SLinus Torvalds 	driver_init();
774b04c3afbSEric W. Biederman 	init_irq_proc();
7751da177e4SLinus Torvalds 	do_initcalls();
7761da177e4SLinus Torvalds }
7771da177e4SLinus Torvalds 
7787babe8dbSEduard - Gabriel Munteanu static void __init do_pre_smp_initcalls(void)
779c2147a50SEduard - Gabriel Munteanu {
780c2147a50SEduard - Gabriel Munteanu 	initcall_t *call;
781c2147a50SEduard - Gabriel Munteanu 
782c2147a50SEduard - Gabriel Munteanu 	for (call = __initcall_start; call < __early_initcall_end; call++)
783c2147a50SEduard - Gabriel Munteanu 		do_one_initcall(*call);
784c2147a50SEduard - Gabriel Munteanu }
785c2147a50SEduard - Gabriel Munteanu 
7861da177e4SLinus Torvalds static void run_init_process(char *init_filename)
7871da177e4SLinus Torvalds {
7881da177e4SLinus Torvalds 	argv_init[0] = init_filename;
78967608567SArnd Bergmann 	kernel_execve(init_filename, argv_init, envp_init);
7901da177e4SLinus Torvalds }
7911da177e4SLinus Torvalds 
792ee5bfa64SVivek Goyal /* This is a non __init function. Force it to be noinline otherwise gcc
793ee5bfa64SVivek Goyal  * makes it inline to init() and it becomes part of init.text section
794ee5bfa64SVivek Goyal  */
795ee5bfa64SVivek Goyal static int noinline init_post(void)
796ee5bfa64SVivek Goyal {
797ee5bfa64SVivek Goyal 	free_initmem();
798ee5bfa64SVivek Goyal 	unlock_kernel();
799ee5bfa64SVivek Goyal 	mark_rodata_ro();
800ee5bfa64SVivek Goyal 	system_state = SYSTEM_RUNNING;
801ee5bfa64SVivek Goyal 	numa_default_policy();
802ee5bfa64SVivek Goyal 
803ee5bfa64SVivek Goyal 	if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
804ee5bfa64SVivek Goyal 		printk(KERN_WARNING "Warning: unable to open an initial console.\n");
805ee5bfa64SVivek Goyal 
806ee5bfa64SVivek Goyal 	(void) sys_dup(0);
807ee5bfa64SVivek Goyal 	(void) sys_dup(0);
808ee5bfa64SVivek Goyal 
809fae5fa44SOleg Nesterov 	current->signal->flags |= SIGNAL_UNKILLABLE;
810fae5fa44SOleg Nesterov 
811ee5bfa64SVivek Goyal 	if (ramdisk_execute_command) {
812ee5bfa64SVivek Goyal 		run_init_process(ramdisk_execute_command);
813ee5bfa64SVivek Goyal 		printk(KERN_WARNING "Failed to execute %s\n",
814ee5bfa64SVivek Goyal 				ramdisk_execute_command);
815ee5bfa64SVivek Goyal 	}
816ee5bfa64SVivek Goyal 
817ee5bfa64SVivek Goyal 	/*
818ee5bfa64SVivek Goyal 	 * We try each of these until one succeeds.
819ee5bfa64SVivek Goyal 	 *
820ee5bfa64SVivek Goyal 	 * The Bourne shell can be used instead of init if we are
821ee5bfa64SVivek Goyal 	 * trying to recover a really broken machine.
822ee5bfa64SVivek Goyal 	 */
823ee5bfa64SVivek Goyal 	if (execute_command) {
824ee5bfa64SVivek Goyal 		run_init_process(execute_command);
825ee5bfa64SVivek Goyal 		printk(KERN_WARNING "Failed to execute %s.  Attempting "
826ee5bfa64SVivek Goyal 					"defaults...\n", execute_command);
827ee5bfa64SVivek Goyal 	}
828ee5bfa64SVivek Goyal 	run_init_process("/sbin/init");
829ee5bfa64SVivek Goyal 	run_init_process("/etc/init");
830ee5bfa64SVivek Goyal 	run_init_process("/bin/init");
831ee5bfa64SVivek Goyal 	run_init_process("/bin/sh");
832ee5bfa64SVivek Goyal 
833ee5bfa64SVivek Goyal 	panic("No init found.  Try passing init= option to kernel.");
834ee5bfa64SVivek Goyal }
835ee5bfa64SVivek Goyal 
836aae5f662SSam Ravnborg static int __init kernel_init(void * unused)
8371da177e4SLinus Torvalds {
8381da177e4SLinus Torvalds 	lock_kernel();
8391da177e4SLinus Torvalds 	/*
8401da177e4SLinus Torvalds 	 * init can run on any cpu.
8411da177e4SLinus Torvalds 	 */
842321a8e9dSMike Travis 	set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
8431da177e4SLinus Torvalds 	/*
8441da177e4SLinus Torvalds 	 * Tell the world that we're going to be the grim
8451da177e4SLinus Torvalds 	 * reaper of innocent orphaned children.
8461da177e4SLinus Torvalds 	 *
8471da177e4SLinus Torvalds 	 * We don't want people to have to make incorrect
8481da177e4SLinus Torvalds 	 * assumptions about where in the task array this
8491da177e4SLinus Torvalds 	 * can be found.
8501da177e4SLinus Torvalds 	 */
85184d73786SSukadev Bhattiprolu 	init_pid_ns.child_reaper = current;
8521da177e4SLinus Torvalds 
8539ec52099SCedric Le Goater 	cad_pid = task_pid(current);
8549ec52099SCedric Le Goater 
855ca74a6f8SAndi Kleen 	smp_prepare_cpus(setup_max_cpus);
8561da177e4SLinus Torvalds 
8571da177e4SLinus Torvalds 	do_pre_smp_initcalls();
8583bf77af6SFrédéric Weisbecker 	start_boot_trace();
8591da177e4SLinus Torvalds 
8601da177e4SLinus Torvalds 	smp_init();
8611da177e4SLinus Torvalds 	sched_init_smp();
8621da177e4SLinus Torvalds 
8631da177e4SLinus Torvalds 	cpuset_init_smp();
8641da177e4SLinus Torvalds 
8651da177e4SLinus Torvalds 	do_basic_setup();
8661da177e4SLinus Torvalds 
8671da177e4SLinus Torvalds 	/*
8681da177e4SLinus Torvalds 	 * check if there is an early userspace init.  If yes, let it do all
8691da177e4SLinus Torvalds 	 * the work
8701da177e4SLinus Torvalds 	 */
871ffdfc409SOlof Johansson 
872ffdfc409SOlof Johansson 	if (!ramdisk_execute_command)
873ffdfc409SOlof Johansson 		ramdisk_execute_command = "/init";
874ffdfc409SOlof Johansson 
875ffdfc409SOlof Johansson 	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
876ffdfc409SOlof Johansson 		ramdisk_execute_command = NULL;
8771da177e4SLinus Torvalds 		prepare_namespace();
878ffdfc409SOlof Johansson 	}
8791da177e4SLinus Torvalds 
8801da177e4SLinus Torvalds 	/*
8811da177e4SLinus Torvalds 	 * Ok, we have completed the initial bootup, and
8821da177e4SLinus Torvalds 	 * we're essentially up and running. Get rid of the
8831da177e4SLinus Torvalds 	 * initmem segments and start the user-mode stuff..
8841da177e4SLinus Torvalds 	 */
885097d036aSFrederic Weisbecker 	stop_boot_trace();
886ee5bfa64SVivek Goyal 	init_post();
887ee5bfa64SVivek Goyal 	return 0;
8881da177e4SLinus Torvalds }
889