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/mp.h>
  38
  39 /* Globals */
  40 void (*PE_kputc)(char c);
  41
  42 unsigned int disable_serial_output = TRUE;
  43
  44 decl_simple_lock_data(static, kprintf_lock)
  45
  46 void PE_init_kprintf(boolean_t vm_initialized)
  47 {
  48         unsigned int    boot_arg;
  49
  50         if (PE_state.initialized == FALSE)
  51                 panic("Platform Expert not initialized");
  52
  53         if (!vm_initialized) {
  54                 simple_lock_init(&kprintf_lock, 0);
  55
  56                 if (PE_parse_boot_arg("debug", &boot_arg))
  57                         if (boot_arg & DB_KPRT)
  58                                 disable_serial_output = FALSE;
  59
  60                 if (!disable_serial_output && serial_init())
  61                         PE_kputc = serial_putc;
  62                 else
  63                         PE_kputc = cnputc;
  64         }
  65 }
  66
  67 #ifdef MP_DEBUG
  68 static void _kprintf(const char *format, ...)
  69 {
  70         va_list   listp;
  71
  72         va_start(listp, format);
  73         _doprnt(format, &listp, PE_kputc, 16);
  74         va_end(listp);
  75 }
  76 #define MP_DEBUG_KPRINTF(x...)  _kprintf(x)
  77 #else  /* MP_DEBUG */
  78 #define MP_DEBUG_KPRINTF(x...)
  79 #endif /* MP_DEBUG */
  80
  81 static int cpu_last_locked = 0;
  82 void kprintf(const char *fmt, ...)
  83 {
  84         va_list   listp;
  85         boolean_t state;
  86
  87         if (!disable_serial_output) {
  88
  89                 /*
  90                  * Spin to get kprintf lock but re-enable interrupts while
  91                  * failing.
  92                  * This allows interrupts to be handled while waiting but
  93                  * interrupts are disabled once we have the lock.
  94                  */
  95                 state = ml_set_interrupts_enabled(FALSE);
  96                 while (!simple_lock_try(&kprintf_lock)) {
  97                         ml_set_interrupts_enabled(state);
  98                         ml_set_interrupts_enabled(FALSE);
  99                 }
 100
 101                 if (cpu_number() != cpu_last_locked) {
 102                         MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
 103                         cpu_last_locked = cpu_number();
 104                 }
 105
 106                 va_start(listp, fmt);
 107                 _doprnt(fmt, &listp, PE_kputc, 16);
 108                 va_end(listp);
 109
 110                 simple_unlock(&kprintf_lock);
 111                 ml_set_interrupts_enabled(state);
 112         }
 113 }
 114
 115 extern void kprintf_break_lock(void);
 116 void
 117 kprintf_break_lock(void)
 118 {
 119         simple_lock_init(&kprintf_lock, 0);
 120 }