source: mainline/uspace/lib/c/arch/ppc32/src/fibril.S@ fc0b2a8

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since fc0b2a8 was a35a3d8, checked in by GitHub <noreply@…>, 7 years ago

Turn context_save/context_restore into standard setjmp/longjmp. (#24)

Turn context_save()/context_restore() into semi-standard __setjmp()/__longjmp().

The original context_* functions are similar to setjmp()/longjmp(), except that the return value is more restricted for the former, and with inverted meaning. This commit adopts the standard return value semantics and acknowledges that these functions are "standard setjmp()/longjmp() with additional implementation-specific properties" by changing the name. The only divergence from the standard is that __longjmp() causes __setjmp() to return its value unchanged, even if it is zero. This is just to avoid extra assembly, and longjmp() checks this in C.

Note that the original use of context_save()/context_restore() to implement context switching in fibril implementation has already been delegated to context_create()/context_swap(), which provide more natural control flow.
  • Property mode set to 100644
File size: 3.2 KB
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1#
2# Copyright (c) 2006 Martin Decky
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.text
30
31#include <abi/asmtool.h>
32#include <libarch/regname.h>
33#include <libarch/fibril_context.h>
34
35FUNCTION_BEGIN(__setjmp)
36 stw sp, CONTEXT_OFFSET_SP(r3)
37 stw r2, CONTEXT_OFFSET_TLS(r3)
38 stw r13, CONTEXT_OFFSET_R13(r3)
39 stw r14, CONTEXT_OFFSET_R14(r3)
40 stw r15, CONTEXT_OFFSET_R15(r3)
41 stw r16, CONTEXT_OFFSET_R16(r3)
42 stw r17, CONTEXT_OFFSET_R17(r3)
43 stw r18, CONTEXT_OFFSET_R18(r3)
44 stw r19, CONTEXT_OFFSET_R19(r3)
45 stw r20, CONTEXT_OFFSET_R20(r3)
46 stw r21, CONTEXT_OFFSET_R21(r3)
47 stw r22, CONTEXT_OFFSET_R22(r3)
48 stw r23, CONTEXT_OFFSET_R23(r3)
49 stw r24, CONTEXT_OFFSET_R24(r3)
50 stw r25, CONTEXT_OFFSET_R25(r3)
51 stw r26, CONTEXT_OFFSET_R26(r3)
52 stw r27, CONTEXT_OFFSET_R27(r3)
53 stw r28, CONTEXT_OFFSET_R28(r3)
54 stw r29, CONTEXT_OFFSET_R29(r3)
55 stw r30, CONTEXT_OFFSET_R30(r3)
56 stw r31, CONTEXT_OFFSET_R31(r3)
57
58 mflr r4
59 stw r4, CONTEXT_OFFSET_PC(r3)
60
61 mfcr r4
62 stw r4, CONTEXT_OFFSET_CR(r3)
63
64 # __setjmp returns 0
65 li r3, 0
66 blr
67FUNCTION_END(__setjmp)
68
69FUNCTION_BEGIN(__longjmp)
70 lwz sp, CONTEXT_OFFSET_SP(r3)
71 lwz r2, CONTEXT_OFFSET_TLS(r3)
72 lwz r13, CONTEXT_OFFSET_R13(r3)
73 lwz r14, CONTEXT_OFFSET_R14(r3)
74 lwz r15, CONTEXT_OFFSET_R15(r3)
75 lwz r16, CONTEXT_OFFSET_R16(r3)
76 lwz r17, CONTEXT_OFFSET_R17(r3)
77 lwz r18, CONTEXT_OFFSET_R18(r3)
78 lwz r19, CONTEXT_OFFSET_R19(r3)
79 lwz r20, CONTEXT_OFFSET_R20(r3)
80 lwz r21, CONTEXT_OFFSET_R21(r3)
81 lwz r22, CONTEXT_OFFSET_R22(r3)
82 lwz r23, CONTEXT_OFFSET_R23(r3)
83 lwz r24, CONTEXT_OFFSET_R24(r3)
84 lwz r25, CONTEXT_OFFSET_R25(r3)
85 lwz r26, CONTEXT_OFFSET_R26(r3)
86 lwz r27, CONTEXT_OFFSET_R27(r3)
87 lwz r28, CONTEXT_OFFSET_R28(r3)
88 lwz r29, CONTEXT_OFFSET_R29(r3)
89 lwz r30, CONTEXT_OFFSET_R30(r3)
90 lwz r31, CONTEXT_OFFSET_R31(r3)
91
92 lwz r5, CONTEXT_OFFSET_CR(r3)
93 mtcr r5
94
95 lwz r5, CONTEXT_OFFSET_PC(r3)
96 mtlr r5
97
98 # __longjmp returns second argument
99 mr r3, r4
100 blr
101FUNCTION_END(__longjmp)
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