[apple/xnu.git] / pexpert / i386 / pe_kprintf.c

/*
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * file: pe_kprintf.c
 *    i386 platform expert debugging output initialization.
 */
#include <stdarg.h>
#include <machine/machine_routines.h>
#include <pexpert/pexpert.h>
#include <kern/debug.h>
#include <kern/simple_lock.h>
#include <i386/mp.h>
#include <machine/pal_routines.h>

/* Globals */
void (*PE_kputc)(char c);

#if DEBUG
/* DEBUG kernel starts with true serial, but
 * may later disable or switch to video
 * console */
unsigned int disable_serial_output = FALSE;
#else
unsigned int disable_serial_output = TRUE;
#endif

decl_simple_lock_data(static, kprintf_lock)

void PE_init_kprintf(boolean_t vm_initialized)
{
	unsigned int	boot_arg;

	if (PE_state.initialized == FALSE)
		panic("Platform Expert not initialized");

	if (!vm_initialized) {
		unsigned int new_disable_serial_output = TRUE;

		simple_lock_init(&kprintf_lock, 0);

		if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
			if (boot_arg & DB_KPRT)
				new_disable_serial_output = FALSE;

		/* If we are newly enabling serial, make sure we only
		 * call pal_serial_init() if our previous state was
		 * not enabled */
		if (!new_disable_serial_output && (!disable_serial_output || pal_serial_init()))
			PE_kputc = pal_serial_putc;
		else
			PE_kputc = cnputc;

		disable_serial_output = new_disable_serial_output;
	}
}

#if CONFIG_NO_KPRINTF_STRINGS
/* Prevent CPP from breaking the definition below */
#undef kprintf
#endif

#ifdef MP_DEBUG
static void _kprintf(const char *format, ...)
{
	va_list   listp;

        va_start(listp, format);
        _doprnt(format, &listp, PE_kputc, 16);
        va_end(listp);
}
#define MP_DEBUG_KPRINTF(x...)	_kprintf(x)
#else  /* MP_DEBUG */
#define MP_DEBUG_KPRINTF(x...)
#endif /* MP_DEBUG */

static int cpu_last_locked = 0;
void kprintf(const char *fmt, ...)
{
	va_list   listp;
	boolean_t state;

	if (!disable_serial_output) {

		/* If PE_kputc has not yet been initialized, don't
		 * take any locks, just dump to serial */
		if (!PE_kputc) {
			va_start(listp, fmt);
			_doprnt(fmt, &listp, pal_serial_putc, 16);
			va_end(listp);
			return;
		}

		/*
		 * Spin to get kprintf lock but re-enable interrupts while
		 * failing.
		 * This allows interrupts to be handled while waiting but
		 * interrupts are disabled once we have the lock.
		 */
		state = ml_set_interrupts_enabled(FALSE);

		pal_preemption_assert();

		while (!simple_lock_try(&kprintf_lock)) {
			ml_set_interrupts_enabled(state);
			ml_set_interrupts_enabled(FALSE);
		}

		if (cpu_number() != cpu_last_locked) {
			MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
			cpu_last_locked = cpu_number();
		}

		va_start(listp, fmt);
		_doprnt(fmt, &listp, PE_kputc, 16);
		va_end(listp);

		simple_unlock(&kprintf_lock);
		ml_set_interrupts_enabled(state);
	}
}

extern void kprintf_break_lock(void);
void
kprintf_break_lock(void)
{
	simple_lock_init(&kprintf_lock, 0);
}
Commit	Line	Data
1c79356b	1	/*
2d21ac55	2	* Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
1c79356b	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* file: pe_kprintf.c
	30	* i386 platform expert debugging output initialization.
	31	*/
	32	#include <stdarg.h>
55e303ae	33	#include <machine/machine_routines.h>
1c79356b A	34	#include <pexpert/pexpert.h>
1c79356b A	35	#include <kern/debug.h>
55e303ae A	36	#include <kern/simple_lock.h>
55e303ae A	37	#include <i386/mp.h>
6d2010ae	38	#include <machine/pal_routines.h>
1c79356b	39
1c79356b	40	/* Globals */
2d21ac55	41	void (*PE_kputc)(char c);
1c79356b	42
b0d623f7 A	43	#if DEBUG
	44	/* DEBUG kernel starts with true serial, but
	45	* may later disable or switch to video
	46	* console */
	47	unsigned int disable_serial_output = FALSE;
	48	#else
2d21ac55	49	unsigned int disable_serial_output = TRUE;
b0d623f7	50	#endif
1c79356b	51
55e303ae A	52	decl_simple_lock_data(static, kprintf_lock)
55e303ae A	53
1c79356b A	54	void PE_init_kprintf(boolean_t vm_initialized)
	55	{
	56	unsigned int boot_arg;
	57
	58	if (PE_state.initialized == FALSE)
	59	panic("Platform Expert not initialized");
	60
2d21ac55	61	if (!vm_initialized) {
b0d623f7 A	62	unsigned int new_disable_serial_output = TRUE;
b0d623f7 A	63
2d21ac55	64	simple_lock_init(&kprintf_lock, 0);
55e303ae	65
593a1d5f	66	if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
2d21ac55	67	if (boot_arg & DB_KPRT)
b0d623f7	68	new_disable_serial_output = FALSE;
55e303ae	69
6d2010ae A	70	/* If we are newly enabling serial, make sure we only
	71	* call pal_serial_init() if our previous state was
	72	* not enabled */
	73	if (!new_disable_serial_output && (!disable_serial_output \|\| pal_serial_init()))
	74	PE_kputc = pal_serial_putc;
2d21ac55 A	75	else
2d21ac55 A	76	PE_kputc = cnputc;
b0d623f7 A	77
b0d623f7 A	78	disable_serial_output = new_disable_serial_output;
2d21ac55	79	}
1c79356b A	80	}
1c79356b A	81
b0d623f7 A	82	#if CONFIG_NO_KPRINTF_STRINGS
	83	/* Prevent CPP from breaking the definition below */
	84	#undef kprintf
	85	#endif
	86
55e303ae A	87	#ifdef MP_DEBUG
	88	static void _kprintf(const char *format, ...)
	89	{
	90	va_list listp;
	91
	92	va_start(listp, format);
	93	_doprnt(format, &listp, PE_kputc, 16);
	94	va_end(listp);
	95	}
	96	#define MP_DEBUG_KPRINTF(x...) _kprintf(x)
	97	#else /* MP_DEBUG */
	98	#define MP_DEBUG_KPRINTF(x...)
	99	#endif /* MP_DEBUG */
	100
	101	static int cpu_last_locked = 0;
1c79356b A	102	void kprintf(const char *fmt, ...)
1c79356b A	103	{
55e303ae	104	va_list listp;
2d21ac55 A	105	boolean_t state;
	106
	107	if (!disable_serial_output) {
	108
b0d623f7 A	109	/* If PE_kputc has not yet been initialized, don't
	110	* take any locks, just dump to serial */
	111	if (!PE_kputc) {
	112	va_start(listp, fmt);
6d2010ae	113	_doprnt(fmt, &listp, pal_serial_putc, 16);
b0d623f7 A	114	va_end(listp);
	115	return;
	116	}
	117
2d21ac55 A	118	/*
	119	* Spin to get kprintf lock but re-enable interrupts while
	120	* failing.
	121	* This allows interrupts to be handled while waiting but
	122	* interrupts are disabled once we have the lock.
	123	*/
	124	state = ml_set_interrupts_enabled(FALSE);
6d2010ae A	125
	126	pal_preemption_assert();
	127
2d21ac55 A	128	while (!simple_lock_try(&kprintf_lock)) {
	129	ml_set_interrupts_enabled(state);
	130	ml_set_interrupts_enabled(FALSE);
	131	}
	132
	133	if (cpu_number() != cpu_last_locked) {
	134	MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
	135	cpu_last_locked = cpu_number();
	136	}
	137
	138	va_start(listp, fmt);
	139	_doprnt(fmt, &listp, PE_kputc, 16);
	140	va_end(listp);
	141
	142	simple_unlock(&kprintf_lock);
	143	ml_set_interrupts_enabled(state);
55e303ae	144	}
1c79356b	145	}
0c530ab8 A	146
	147	extern void kprintf_break_lock(void);
	148	void
	149	kprintf_break_lock(void)
	150	{
	151	simple_lock_init(&kprintf_lock, 0);
	152	}