pexpert/i386/pe_kprintf.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * file: pe_kprintf.c
  24  *    i386 platform expert debugging output initialization.
  25  */
  26 #include <stdarg.h>
  27 #include <machine/machine_routines.h>
  28 #include <pexpert/pexpert.h>
  29 #include <kern/debug.h>
  30 #include <kern/simple_lock.h>
  31 #include <i386/mp.h>
  32
  33 /* extern references */
  34 extern void cnputc(char c);
  35 extern int  serial_init(void);
  36 extern void serial_putc(char c);
  37
  38 /* Globals */
  39 void (*PE_kputc)(char c) = 0;
  40
  41 unsigned int disableSerialOuput = TRUE;
  42
  43 decl_simple_lock_data(static, kprintf_lock)
  44
  45 void PE_init_kprintf(boolean_t vm_initialized)
  46 {
  47         unsigned int    boot_arg;
  48
  49         if (PE_state.initialized == FALSE)
  50                 panic("Platform Expert not initialized");
  51
  52         if (!vm_initialized)
  53         {
  54         simple_lock_init(&kprintf_lock, 0);
  55
  56             if (PE_parse_boot_arg("debug", &boot_arg))
  57                 if (boot_arg & DB_KPRT) disableSerialOuput = FALSE;
  58
  59         if (!disableSerialOuput && serial_init())
  60             PE_kputc = serial_putc;
  61         else
  62             PE_kputc = cnputc;
  63     }
  64 }
  65
  66 #ifdef MP_DEBUG
  67 static void _kprintf(const char *format, ...)
  68 {
  69         va_list   listp;
  70
  71         va_start(listp, format);
  72         _doprnt(format, &listp, PE_kputc, 16);
  73         va_end(listp);
  74 }
  75 #define MP_DEBUG_KPRINTF(x...)  _kprintf(x)
  76 #else  /* MP_DEBUG */
  77 #define MP_DEBUG_KPRINTF(x...)
  78 #endif /* MP_DEBUG */
  79
  80 static int cpu_last_locked = 0;
  81 void kprintf(const char *fmt, ...)
  82 {
  83         va_list   listp;
  84     boolean_t state;
  85
  86     if (!disableSerialOuput) {
  87
  88         /*
  89          * Spin to get kprintf lock but re-enable interrupts while failing.
  90          * This allows interrupts to be handled while waiting but
  91          * interrupts are disabled once we have the lock.
  92          */
  93         state = ml_set_interrupts_enabled(FALSE);
  94         while (!simple_lock_try(&kprintf_lock)) {
  95              ml_set_interrupts_enabled(state);
  96              ml_set_interrupts_enabled(FALSE);
  97         }
  98
  99         if (cpu_number() != cpu_last_locked) {
 100             MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
 101             cpu_last_locked = cpu_number();
 102         }
 103
 104         va_start(listp, fmt);
 105         _doprnt(fmt, &listp, PE_kputc, 16);
 106         va_end(listp);
 107
 108         simple_unlock(&kprintf_lock);
 109         ml_set_interrupts_enabled(state);
 110     }
 111 }