pexpert/i386/pe_kprintf.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * file: pe_kprintf.c
  25  *    i386 platform expert debugging output initialization.
  26  */
  27 #include <stdarg.h>
  28 #include <machine/machine_routines.h>
  29 #include <pexpert/pexpert.h>
  30 #include <kern/debug.h>
  31 #include <kern/simple_lock.h>
  32 #include <i386/mp.h>
  33
  34 /* extern references */
  35 extern void cnputc(char c);
  36 extern int  serial_init(void);
  37 extern void serial_putc(char c);
  38
  39 /* Globals */
  40 void (*PE_kputc)(char c) = 0;
  41
  42 unsigned int disableSerialOuput = 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         {
  55         simple_lock_init(&kprintf_lock, 0);
  56
  57             if (PE_parse_boot_arg("debug", &boot_arg))
  58                 if (boot_arg & DB_KPRT) disableSerialOuput = FALSE;
  59
  60         if (!disableSerialOuput && 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 (!disableSerialOuput) {
  88
  89         /*
  90          * Spin to get kprintf lock but re-enable interrupts while failing.
  91          * This allows interrupts to be handled while waiting but
  92          * interrupts are disabled once we have the lock.
  93          */
  94         state = ml_set_interrupts_enabled(FALSE);
  95         while (!simple_lock_try(&kprintf_lock)) {
  96              ml_set_interrupts_enabled(state);
  97              ml_set_interrupts_enabled(FALSE);
  98         }
  99
 100         if (cpu_number() != cpu_last_locked) {
 101             MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
 102             cpu_last_locked = cpu_number();
 103         }
 104
 105         va_start(listp, fmt);
 106         _doprnt(fmt, &listp, PE_kputc, 16);
 107         va_end(listp);
 108
 109         simple_unlock(&kprintf_lock);
 110         ml_set_interrupts_enabled(state);
 111     }
 112 }