xnu-792.6.56.tar.gz

[apple/xnu.git] / pexpert / i386 / pe_kprintf.c

diff --git a/pexpert/i386/pe_kprintf.c b/pexpert/i386/pe_kprintf.c
index 3d00e68f969108423ab6e95d2c66f18b2b5f90c6..47788ec82593756d8cecb712d191216b3d4bb2fd 100644 (file)
--- a/pexpert/i386/pe_kprintf.c
+++ b/pexpert/i386/pe_kprintf.c
@@ -3,8 +3,6 @@
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
- * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
@@ -27,17 +25,24 @@
  *    i386 platform expert debugging output initialization.
  */
 #include <stdarg.h>
+#include <machine/machine_routines.h>
 #include <pexpert/pexpert.h>
 #include <kern/debug.h>
+#include <kern/simple_lock.h>
+#include <i386/mp.h>
 
 /* extern references */
 extern void cnputc(char c);
+extern int  serial_init(void);
+extern void serial_putc(char c);
 
 /* Globals */
 void (*PE_kputc)(char c) = 0;
 
 unsigned int disableSerialOuput = TRUE;
 
+decl_simple_lock_data(static, kprintf_lock)
+
 void PE_init_kprintf(boolean_t vm_initialized)
 {
        unsigned int    boot_arg;
@@ -47,21 +52,61 @@ void PE_init_kprintf(boolean_t vm_initialized)
 
        if (!vm_initialized)
        {
+        simple_lock_init(&kprintf_lock, 0);
+
            if (PE_parse_boot_arg("debug", &boot_arg)) 
                if (boot_arg & DB_KPRT) disableSerialOuput = FALSE;
-        
-        /* FIXME - route output to serial port. */
-        PE_kputc = cnputc;
+
+        if (!disableSerialOuput && serial_init())
+            PE_kputc = serial_putc;
+        else
+            PE_kputc = cnputc;
     }
 }
 
+#ifdef MP_DEBUG
+static void _kprintf(const char *format, ...)
+{
+       va_list   listp;
+
+        va_start(listp, format);
+        _doprnt(format, &listp, PE_kputc, 16);
+        va_end(listp);
+}
+#define MP_DEBUG_KPRINTF(x...) _kprintf(x)
+#else  /* MP_DEBUG */
+#define MP_DEBUG_KPRINTF(x...)
+#endif /* MP_DEBUG */
+
+static int cpu_last_locked = 0;
 void kprintf(const char *fmt, ...)
 {
-       va_list listp;
+       va_list   listp;
+    boolean_t state;
     
     if (!disableSerialOuput) {
+
+       /*
+        * Spin to get kprintf lock but re-enable interrupts while failing.
+        * This allows interrupts to be handled while waiting but
+        * interrupts are disabled once we have the lock.
+        */
+       state = ml_set_interrupts_enabled(FALSE);
+       while (!simple_lock_try(&kprintf_lock)) {
+             ml_set_interrupts_enabled(state);
+             ml_set_interrupts_enabled(FALSE);
+       }
+
+       if (cpu_number() != cpu_last_locked) {
+           MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
+           cpu_last_locked = cpu_number();
+       }
+
         va_start(listp, fmt);
         _doprnt(fmt, &listp, PE_kputc, 16);
         va_end(listp);
+
+        simple_unlock(&kprintf_lock);
+        ml_set_interrupts_enabled(state);
     }
 }