LXR darwin-xnu/pexpert/i386/pe

   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 */
  34extern void cnputc(char c);
  35extern int  serial_init(void);
  36extern void serial_putc(char c);
  37
  38/* Globals */
  39void (*PE_kputc)(char c) = 0;
  40
  41unsigned int disableSerialOuput = TRUE;
  42
  43decl_simple_lock_data(static, kprintf_lock)
  44
  45void 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
  67static 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
  80static int cpu_last_locked = 0;
  81void 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}
 112