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/machine_cpu.h>
38#include <i386/mp.h>
39#include <machine/pal_routines.h>
40#include <i386/proc_reg.h>
41#include <os/log_private.h>
42#include <libkern/section_keywords.h>
43
44/* Globals */
45void (*PE_kputc)(char c);
46
47#if DEVELOPMENT || DEBUG
48/* DEBUG kernel starts with true serial, but
49 * may later disable or switch to video
50 * console */
51SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = FALSE;
52#else
53SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = TRUE;
54#endif
55
56decl_simple_lock_data(static, kprintf_lock)
57
58void PE_init_kprintf(boolean_t vm_initialized)
59{
60 unsigned int boot_arg;
61
62 if (PE_state.initialized == FALSE)
63 panic("Platform Expert not initialized");
64
65 if (!vm_initialized) {
66 unsigned int new_disable_serial_output = TRUE;
67
68 simple_lock_init(&kprintf_lock, 0);
69
70 if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
71 if (boot_arg & DB_KPRT)
72 new_disable_serial_output = FALSE;
73
74 /* If we are newly enabling serial, make sure we only
75 * call pal_serial_init() if our previous state was
76 * not enabled */
77 if (!new_disable_serial_output && (!disable_serial_output || pal_serial_init()))
78 PE_kputc = pal_serial_putc;
79 else
80 PE_kputc = cnputc;
81
82 disable_serial_output = new_disable_serial_output;
83 }
84}
85
86#if CONFIG_NO_KPRINTF_STRINGS
87/* Prevent CPP from breaking the definition below */
88#undef kprintf
89#endif
90
91#ifdef MP_DEBUG
92static void _kprintf(const char *format, ...)
93{
94 va_list listp;
95
96 va_start(listp, format);
97 _doprnt(format, &listp, PE_kputc, 16);
98 va_end(listp);
99}
100#define MP_DEBUG_KPRINTF(x...) _kprintf(x)
101#else /* MP_DEBUG */
102#define MP_DEBUG_KPRINTF(x...)
103#endif /* MP_DEBUG */
104
105static int cpu_last_locked = 0;
106
107__attribute__((noinline,not_tail_called))
108void kprintf(const char *fmt, ...)
109{
110 va_list listp;
111 va_list listp2;
112 boolean_t state;
113 void *caller = __builtin_return_address(0);
114
115 if (!disable_serial_output) {
116 boolean_t early = FALSE;
117 if (rdmsr64(MSR_IA32_GS_BASE) == 0) {
118 early = TRUE;
119 }
120 /* If PE_kputc has not yet been initialized, don't
121 * take any locks, just dump to serial */
122 if (!PE_kputc || early) {
123 va_start(listp, fmt);
124 va_copy(listp2, listp);
125
126 _doprnt_log(fmt, &listp, pal_serial_putc, 16);
127 va_end(listp);
128
129 // If interrupts are enabled
130 if (ml_get_interrupts_enabled()) {
131 os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
132 }
133 va_end(listp2);
134 return;
135 }
136
137 /*
138 * Spin to get kprintf lock but poll for incoming signals
139 * while interrupts are masked.
140 */
141 state = ml_set_interrupts_enabled(FALSE);
142
143 pal_preemption_assert();
144
145 while (!simple_lock_try(&kprintf_lock)) {
146 (void) cpu_signal_handler(NULL);
147 }
148
149 if (cpu_number() != cpu_last_locked) {
150 MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
151 cpu_last_locked = cpu_number();
152 }
153
154 va_start(listp, fmt);
155 va_copy(listp2, listp);
156 _doprnt(fmt, &listp, PE_kputc, 16);
157 va_end(listp);
158
159 simple_unlock(&kprintf_lock);
160 ml_set_interrupts_enabled(state);
161
162 // If interrupts are enabled
163 if (ml_get_interrupts_enabled()) {
164 os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
165 }
166 va_end(listp2);
167
168 }
169 else {
170 if (ml_get_interrupts_enabled()) {
171 va_start(listp, fmt);
172 os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp, caller);
173 va_end(listp);
174 }
175 }
176}
177
178
179
180extern void kprintf_break_lock(void);
181void
182kprintf_break_lock(void)
183{
184 simple_lock_init(&kprintf_lock, 0);
185}
186