Commit | Line | Data |
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1da177e4 LT |
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 __get_datapage@local | |
60 | mtlr r12 | |
61 | addi r3,r3,CFG_SYSCALL_MAP32 | |
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) |