xref: /illumos-gate/usr/src/uts/sun4u/sunfire/ml/fhc_asm.S (revision 55fea89dcaa64928bed4327112404dcb3e07b79f)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#include <sys/param.h>
28#include <sys/errno.h>
29#include <sys/asm_linkage.h>
30#include <sys/machthread.h>
31#include <sys/asi.h>
32#include <sys/privregs.h>
33#include <sys/spitregs.h>
34
35#include "assym.h"
36
37/*
38 * fhc_shutdown_asm(u_longlong_t base, int size)
39 *
40 * Flush cpu E$ then shutdown.
41 * This function is special in that it really sets the D-tags to
42 * a known state.  And this is the behavior we're looking for.
43 *
44 * The flush address is known to be a cpu-unique non-existent
45 * cacheable address.  We write to non-existent memory, using
46 * the side effect of d-tag invalidation.
47 *
48 * Also, note that this function is never run from main memory.
49 * Rather it is copied to non-cacheable SRAM (hence the ..._end
50 * label at the bottom of the function).  This implies that the
51 * function must be position independent code that doesn't reference
52 * cacheable real memory.
53 */
54
55	ENTRY(fhc_shutdown_asm)
56	! turn off errors (we'll be writing to non-existent memory)
57	stxa	%g0, [%g0]ASI_ESTATE_ERR
58	membar	#Sync			! SYNC
59
60	rdpr	%pstate, %o4
61	andn	%o4, PSTATE_IE | PSTATE_AM, %o3
62	wrpr	%o3, %g0, %pstate
631:
64	brlez,pn %o1, 2f		! if (len <= 0) exit loop
65	  dec	64, %o1			! size -= 64
66        sta     %g0, [%o0]ASI_MEM	! store (unpopulated) word
67	ba	1b
68	  inc	64, %o0			! addr += 64
692:
70	membar  #Sync			! SYNC
71	shutdown			! SHUTDOWN
72	/*NOTREACHED*/
73
74	! if, for some reason, this cpu doesn't shutdown, just sit here
753:
76	ba	3b
77	  nop				! eventually the master will notice
78	SET_SIZE(fhc_shutdown_asm)
79
80	.global	fhc_shutdown_asm_end
81fhc_shutdown_asm_end:
82
83