1/*
2 * Copyright (c) 2000-2005 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 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56/*
57 * xpr silent tracing circular buffer.
58 */
59
60#include <mach/machine/vm_types.h>
61#include <kern/xpr.h>
62#include <kern/lock.h>
63#include <kern/spl.h>
64#include <kern/cpu_number.h>
65#include <kern/misc_protos.h>
66#include <kern/thread.h>
67#include <vm/vm_kern.h>
68#include <string.h>
69
70/*
71 *	After a spontaneous reboot, it is desirable to look
72 *	at the old xpr buffer.  Assuming xprbootstrap allocates
73 *	the buffer in the same place in physical memory and
74 *	the reboot doesn't clear memory, this should work.
75 *	xprptr will be reset, but the saved value should be OK.
76 *	Just set xprenable false so the buffer isn't overwritten.
77 */
78
79decl_simple_lock_data(,xprlock)
80boolean_t xprenable = TRUE;	/* Enable xpr tracing */
81int nxprbufs = 0;	/* Number of contiguous xprbufs allocated */
82int xprflags = 0;	/* Bit mask of xpr flags enabled */
83struct xprbuf *xprbase;	/* Pointer to circular buffer nxprbufs*sizeof(xprbuf)*/
84struct xprbuf *xprptr;	/* Currently allocated xprbuf */
85struct xprbuf *xprlast;	/* Pointer to end of circular buffer */
86
87void
88xpr(
89	const char	*msg,
90	long		arg1,
91	long		arg2,
92	long		arg3,
93	long		arg4,
94	long		arg5)
95{
96	spl_t s;
97	register struct xprbuf *x;
98
99	/* If we aren't initialized, ignore trace request */
100	if (!xprenable || (xprptr == 0))
101		return;
102	/* Guard against all interrupts and allocate next buffer. */
103
104	s = splhigh();
105	simple_lock(&xprlock);
106	x = xprptr++;
107	if (xprptr >= xprlast) {
108		/* wrap around */
109		xprptr = xprbase;
110	}
111	/* Save xprptr in allocated memory. */
112	*(struct xprbuf **)xprlast = xprptr;
113	simple_unlock(&xprlock);
114	x->timestamp = XPR_TIMESTAMP;
115	splx(s);
116	x->msg = msg;
117	x->arg1 = arg1;
118	x->arg2 = arg2;
119	x->arg3 = arg3;
120	x->arg4 = arg4;
121	x->arg5 = arg5;
122	mp_disable_preemption();
123	x->cpuinfo = cpu_number();
124	mp_enable_preemption();
125}
126
127