source: mainline/kernel/arch/sparc64/src/context.S@ 245e8399

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 245e8399 was 245e8399, checked in by Jakub Jermar <jakub@…>, 16 years ago

Flush windows in context_save_arch() instead of context_restore_arch().

  • Property mode set to 100644
File size: 2.6 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#include <arch/arch.h>
31#include <arch/regdef.h>
32
33.text
34
35.global context_save_arch
36.global context_restore_arch
37
38/*
39 * context_save_arch() is required not to create its own stack frame. See the
40 * generic context.h for explanation.
41 */
42context_save_arch:
43 #
44 # Force all our active register windows to memory so that we can find
45 # them there even if e.g. the thread is migrated to another processor.
46 #
47 flushw
48
49 CONTEXT_SAVE_ARCH_CORE %o0
50 retl
51 mov 1, %o0 ! context_save_arch returns 1
52
53context_restore_arch:
54 #
55 # Forget all previous windows, they are not going to be needed again.
56 # Enforce a window fill on the next RESTORE instruction by setting
57 # CANRESTORE to zero and other window configuration registers
58 # accordingly. Note that the same can be achieved by executing the
59 # FLUSHW instruction, but since we don't need to remember the previous
60 # windows, we do the former and save thus some unnecessary window
61 # spills.
62 #
63 rdpr %pstate, %l0
64 andn %l0, PSTATE_IE_BIT, %l1
65 wrpr %l1, %pstate
66 wrpr %g0, 0, %canrestore
67 wrpr %g0, 0, %otherwin
68 wrpr %g0, NWINDOWS - 2, %cansave
69 wrpr %l0, %pstate
70
71 CONTEXT_RESTORE_ARCH_CORE %o0
72 retl
73 xor %o0, %o0, %o0 ! context_restore_arch returns 0
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