[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>
#include <i386/proc_reg.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) {
		boolean_t early = FALSE;
		if (rdmsr64(MSR_IA32_GS_BASE) == 0) {
			early = TRUE;
		}
		/* If PE_kputc has not yet been initialized, don't
		 * take any locks, just dump to serial */
		if (!PE_kputc || early) {
			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>
7ddcb079	39	#include <i386/proc_reg.h>
1c79356b	40
1c79356b	41	/* Globals */
2d21ac55	42	void (*PE_kputc)(char c);
1c79356b	43
b0d623f7 A	44	#if DEBUG
	45	/* DEBUG kernel starts with true serial, but
	46	* may later disable or switch to video
	47	* console */
	48	unsigned int disable_serial_output = FALSE;
	49	#else
2d21ac55	50	unsigned int disable_serial_output = TRUE;
b0d623f7	51	#endif
1c79356b	52
55e303ae A	53	decl_simple_lock_data(static, kprintf_lock)
55e303ae A	54
1c79356b A	55	void PE_init_kprintf(boolean_t vm_initialized)
	56	{
	57	unsigned int boot_arg;
	58
	59	if (PE_state.initialized == FALSE)
	60	panic("Platform Expert not initialized");
	61
2d21ac55	62	if (!vm_initialized) {
b0d623f7 A	63	unsigned int new_disable_serial_output = TRUE;
b0d623f7 A	64
2d21ac55	65	simple_lock_init(&kprintf_lock, 0);
55e303ae	66
593a1d5f	67	if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
2d21ac55	68	if (boot_arg & DB_KPRT)
b0d623f7	69	new_disable_serial_output = FALSE;
55e303ae	70
6d2010ae A	71	/* If we are newly enabling serial, make sure we only
	72	* call pal_serial_init() if our previous state was
	73	* not enabled */
	74	if (!new_disable_serial_output && (!disable_serial_output \|\| pal_serial_init()))
	75	PE_kputc = pal_serial_putc;
2d21ac55 A	76	else
2d21ac55 A	77	PE_kputc = cnputc;
b0d623f7 A	78
b0d623f7 A	79	disable_serial_output = new_disable_serial_output;
2d21ac55	80	}
1c79356b A	81	}
1c79356b A	82
b0d623f7 A	83	#if CONFIG_NO_KPRINTF_STRINGS
	84	/* Prevent CPP from breaking the definition below */
	85	#undef kprintf
	86	#endif
	87
55e303ae A	88	#ifdef MP_DEBUG
	89	static void _kprintf(const char *format, ...)
	90	{
	91	va_list listp;
	92
	93	va_start(listp, format);
	94	_doprnt(format, &listp, PE_kputc, 16);
	95	va_end(listp);
	96	}
	97	#define MP_DEBUG_KPRINTF(x...) _kprintf(x)
	98	#else /* MP_DEBUG */
	99	#define MP_DEBUG_KPRINTF(x...)
	100	#endif /* MP_DEBUG */
	101
	102	static int cpu_last_locked = 0;
1c79356b A	103	void kprintf(const char *fmt, ...)
1c79356b A	104	{
55e303ae	105	va_list listp;
2d21ac55 A	106	boolean_t state;
	107
	108	if (!disable_serial_output) {
7ddcb079 A	109	boolean_t early = FALSE;
	110	if (rdmsr64(MSR_IA32_GS_BASE) == 0) {
	111	early = TRUE;
	112	}
b0d623f7 A	113	/* If PE_kputc has not yet been initialized, don't
b0d623f7 A	114	* take any locks, just dump to serial */
7ddcb079	115	if (!PE_kputc \|\| early) {
b0d623f7	116	va_start(listp, fmt);
6d2010ae	117	_doprnt(fmt, &listp, pal_serial_putc, 16);
b0d623f7 A	118	va_end(listp);
	119	return;
	120	}
	121
2d21ac55 A	122	/*
	123	* Spin to get kprintf lock but re-enable interrupts while
	124	* failing.
	125	* This allows interrupts to be handled while waiting but
	126	* interrupts are disabled once we have the lock.
	127	*/
	128	state = ml_set_interrupts_enabled(FALSE);
6d2010ae A	129
	130	pal_preemption_assert();
	131
2d21ac55 A	132	while (!simple_lock_try(&kprintf_lock)) {
	133	ml_set_interrupts_enabled(state);
	134	ml_set_interrupts_enabled(FALSE);
	135	}
	136
	137	if (cpu_number() != cpu_last_locked) {
	138	MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
	139	cpu_last_locked = cpu_number();
	140	}
	141
	142	va_start(listp, fmt);
	143	_doprnt(fmt, &listp, PE_kputc, 16);
	144	va_end(listp);
	145
	146	simple_unlock(&kprintf_lock);
	147	ml_set_interrupts_enabled(state);
55e303ae	148	}
1c79356b	149	}
0c530ab8 A	150
	151	extern void kprintf_break_lock(void);
	152	void
	153	kprintf_break_lock(void)
	154	{
	155	simple_lock_init(&kprintf_lock, 0);
	156	}