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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc64/kernel/vdso64/datapage.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ppc64/kernel/vdso64/datapage.S')
-rw-r--r--arch/ppc64/kernel/vdso64/datapage.S68
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/vdso64/datapage.S b/arch/ppc64/kernel/vdso64/datapage.S
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index 000000000000..18afd971c9d9
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@@ -0,0 +1,68 @@
1/*
2 * Access to the shared data page by the vDSO & syscall map
3 *
4 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/config.h>
13#include <asm/processor.h>
14#include <asm/ppc_asm.h>
15#include <asm/offsets.h>
16#include <asm/unistd.h>
17#include <asm/vdso.h>
18
19 .text
20V_FUNCTION_BEGIN(__get_datapage)
21 .cfi_startproc
22 /* We don't want that exposed or overridable as we want other objects
23 * to be able to bl directly to here
24 */
25 .protected __get_datapage
26 .hidden __get_datapage
27
28 mflr r0
29 .cfi_register lr,r0
30
31 bcl 20,31,1f
32 .global __kernel_datapage_offset;
33__kernel_datapage_offset:
34 .long 0
351:
36 mflr r3
37 mtlr r0
38 lwz r0,0(r3)
39 add r3,r0,r3
40 blr
41 .cfi_endproc
42V_FUNCTION_END(__get_datapage)
43
44/*
45 * void *__kernel_get_syscall_map(unsigned int *syscall_count) ;
46 *
47 * returns a pointer to the syscall map. the map is agnostic to the
48 * size of "long", unlike kernel bitops, it stores bits from top to
49 * bottom so that memory actually contains a linear bitmap
50 * check for syscall N by testing bit (0x80000000 >> (N & 0x1f)) of
51 * 32 bits int at N >> 5.
52 */
53V_FUNCTION_BEGIN(__kernel_get_syscall_map)
54 .cfi_startproc
55 mflr r12
56 .cfi_register lr,r12
57
58 mr r4,r3
59 bl V_LOCAL_FUNC(__get_datapage)
60 mtlr r12
61 addi r3,r3,CFG_SYSCALL_MAP64
62 cmpli cr0,r4,0
63 beqlr
64 li r0,__NR_syscalls
65 stw r0,0(r4)
66 blr
67 .cfi_endproc
68V_FUNCTION_END(__kernel_get_syscall_map)