pexpert/i386/pe_kprintf.c

   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 */
  45 void (*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 */
  51 SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = FALSE;
  52 #else
  53 SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = TRUE;
  54 #endif
  55
  56 decl_simple_lock_data(static, kprintf_lock)
  57
  58 void 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
  92 static 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
 105 static int cpu_last_locked = 0;
 106
 107 __attribute__((noinline,not_tail_called))
 108 void 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
 180 extern void kprintf_break_lock(void);
 181 void
 182 kprintf_break_lock(void)
 183 {
 184         simple_lock_init(&kprintf_lock, 0);
 185 }