pexpert/i386/pe_kprintf.c

   1 /*
   2  * Copyright (c) 2000 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 /* extern references */
  40 extern void cnputc(char c);
  41 extern int  serial_init(void);
  42 extern void serial_putc(char c);
  43
  44 /* Globals */
  45 void (*PE_kputc)(char c) = 0;
  46
  47 unsigned int disableSerialOuput = TRUE;
  48
  49 decl_simple_lock_data(static, kprintf_lock)
  50
  51 void PE_init_kprintf(boolean_t vm_initialized)
  52 {
  53         unsigned int    boot_arg;
  54
  55         if (PE_state.initialized == FALSE)
  56                 panic("Platform Expert not initialized");
  57
  58         if (!vm_initialized)
  59         {
  60         simple_lock_init(&kprintf_lock, 0);
  61
  62             if (PE_parse_boot_arg("debug", &boot_arg))
  63                 if (boot_arg & DB_KPRT) disableSerialOuput = FALSE;
  64
  65         if (!disableSerialOuput && serial_init())
  66             PE_kputc = serial_putc;
  67         else
  68             PE_kputc = cnputc;
  69     }
  70 }
  71
  72 #ifdef MP_DEBUG
  73 static void _kprintf(const char *format, ...)
  74 {
  75         va_list   listp;
  76
  77         va_start(listp, format);
  78         _doprnt(format, &listp, PE_kputc, 16);
  79         va_end(listp);
  80 }
  81 #define MP_DEBUG_KPRINTF(x...)  _kprintf(x)
  82 #else  /* MP_DEBUG */
  83 #define MP_DEBUG_KPRINTF(x...)
  84 #endif /* MP_DEBUG */
  85
  86 static int cpu_last_locked = 0;
  87 void kprintf(const char *fmt, ...)
  88 {
  89         va_list   listp;
  90     boolean_t state;
  91
  92     if (!disableSerialOuput) {
  93
  94         /*
  95          * Spin to get kprintf lock but re-enable interrupts while failing.
  96          * This allows interrupts to be handled while waiting but
  97          * interrupts are disabled once we have the lock.
  98          */
  99         state = ml_set_interrupts_enabled(FALSE);
 100         while (!simple_lock_try(&kprintf_lock)) {
 101              ml_set_interrupts_enabled(state);
 102              ml_set_interrupts_enabled(FALSE);
 103         }
 104
 105         if (cpu_number() != cpu_last_locked) {
 106             MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
 107             cpu_last_locked = cpu_number();
 108         }
 109
 110         va_start(listp, fmt);
 111         _doprnt(fmt, &listp, PE_kputc, 16);
 112         va_end(listp);
 113
 114         simple_unlock(&kprintf_lock);
 115         ml_set_interrupts_enabled(state);
 116     }
 117 }