source: mainline/kernel/arch/sparc64/src/context.S@ f238e86

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since f238e86 was ecc83bd, checked in by Josef Cejka <malyzelenyhnus@…>, 17 years ago

Context handling unified for sparc64.

  • Property mode set to 100644
File size: 2.2 KB
Line 
1#
2# Copyright (c) 2005 Jakub Jermar
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms, with or without
6# modification, are permitted provided that the following conditions
7# are met:
8#
9# - Redistributions of source code must retain the above copyright
10# notice, this list of conditions and the following disclaimer.
11# - Redistributions in binary form must reproduce the above copyright
12# notice, this list of conditions and the following disclaimer in the
13# documentation and/or other materials provided with the distribution.
14# - The name of the author may not be used to endorse or promote products
15# derived from this software without specific prior written permission.
16#
17# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27#
28
29#include <arch/context_offset.h>
30
31/**
32 * Both context_save_arch() and context_restore_arch() are
33 * leaf-optimized procedures. This kind of optimization
34 * is very important and prevents any implicit window
35 * spill/fill/clean traps in these very core kernel
36 * functions.
37 */
38
39#include <arch/context_offset.h>
40
41.text
42
43.global context_save_arch
44.global context_restore_arch
45
46context_save_arch:
47 CONTEXT_SAVE_ARCH_CORE %o0
48 retl
49 mov 1, %o0 ! context_save_arch returns 1
50
51context_restore_arch:
52 #
53 # Flush all active windows.
54 # This is essential, because CONTEXT_LOAD overwrites
55 # %sp of CWP - 1 with the value written to %fp of CWP.
56 # Flushing all active windows mitigates this problem
57 # as CWP - 1 becomes the overlap window.
58 #
59 flushw
60
61 CONTEXT_RESTORE_ARCH_CORE %o0
62 retl
63 xor %o0, %o0, %o0 ! context_restore_arch returns 0
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