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