diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /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.S | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/vdso64/datapage.S b/arch/ppc64/kernel/vdso64/datapage.S new file mode 100644 index 000000000000..18afd971c9d9 --- /dev/null +++ b/arch/ppc64/kernel/vdso64/datapage.S | |||
@@ -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 | ||
20 | V_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 | ||
35 | 1: | ||
36 | mflr r3 | ||
37 | mtlr r0 | ||
38 | lwz r0,0(r3) | ||
39 | add r3,r0,r3 | ||
40 | blr | ||
41 | .cfi_endproc | ||
42 | V_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 | */ | ||
53 | V_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 | ||
68 | V_FUNCTION_END(__kernel_get_syscall_map) | ||