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	1	/*
	2	* Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	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.
	14	*
	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
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	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.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28	/*
	29	* file: pe_kprintf.c
	30	* i386 platform expert debugging output initialization.
	31	*/
	32	#include <stdarg.h>
	33	#include <machine/machine_routines.h>
	34	#include <pexpert/pexpert.h>
	35	#include <kern/debug.h>
	36	#include <kern/simple_lock.h>
	37	#include <i386/mp.h>
	38	#include <machine/pal_routines.h>
	39
	40	/* Globals */
	41	void (*PE_kputc)(char c);
	42
	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
	49	unsigned int disable_serial_output = TRUE;
	50	#endif
	51
	52	decl_simple_lock_data(static, kprintf_lock)
	53
	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
	61	if (!vm_initialized) {
	62	unsigned int new_disable_serial_output = TRUE;
	63
	64	simple_lock_init(&kprintf_lock, 0);
	65
	66	if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
	67	if (boot_arg & DB_KPRT)
	68	new_disable_serial_output = FALSE;
	69
	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;
	75	else
	76	PE_kputc = cnputc;
	77
	78	disable_serial_output = new_disable_serial_output;
	79	}
	80	}
	81
	82	#if CONFIG_NO_KPRINTF_STRINGS
	83	/* Prevent CPP from breaking the definition below */
	84	#undef kprintf
	85	#endif
	86
	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;
	102	void kprintf(const char *fmt, ...)
	103	{
	104	va_list listp;
	105	boolean_t state;
	106
	107	if (!disable_serial_output) {
	108
	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);
	113	_doprnt(fmt, &listp, pal_serial_putc, 16);
	114	va_end(listp);
	115	return;
	116	}
	117
	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);
	125
	126	pal_preemption_assert();
	127
	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);
	144	}
	145	}
	146
	147	extern void kprintf_break_lock(void);
	148	void
	149	kprintf_break_lock(void)
	150	{
	151	simple_lock_init(&kprintf_lock, 0);
	152	}