blob: dc21e891d2e71b12ebc1dfb709357689dc089fd2 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <asm/processor.h>
13#include <asm/ppc_asm.h>
Sam Ravnborg0013a852005-09-09 20:57:26 +020014#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/unistd.h>
16#include <asm/vdso.h>
17
18 .text
19V_FUNCTION_BEGIN(__get_datapage)
20 .cfi_startproc
21 /* We don't want that exposed or overridable as we want other objects
22 * to be able to bl directly to here
23 */
24 .protected __get_datapage
25 .hidden __get_datapage
26
27 mflr r0
28 .cfi_register lr,r0
29
30 bcl 20,31,1f
31 .global __kernel_datapage_offset;
32__kernel_datapage_offset:
33 .long 0
341:
35 mflr r3
36 mtlr r0
37 lwz r0,0(r3)
38 add r3,r0,r3
39 blr
40 .cfi_endproc
41V_FUNCTION_END(__get_datapage)
42
43/*
44 * void *__kernel_get_syscall_map(unsigned int *syscall_count) ;
45 *
46 * returns a pointer to the syscall map. the map is agnostic to the
47 * size of "long", unlike kernel bitops, it stores bits from top to
48 * bottom so that memory actually contains a linear bitmap
49 * check for syscall N by testing bit (0x80000000 >> (N & 0x1f)) of
50 * 32 bits int at N >> 5.
51 */
52V_FUNCTION_BEGIN(__kernel_get_syscall_map)
53 .cfi_startproc
54 mflr r12
55 .cfi_register lr,r12
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 mr r4,r3
57 bl __get_datapage@local
58 mtlr r12
59 addi r3,r3,CFG_SYSCALL_MAP32
60 cmpli cr0,r4,0
61 beqlr
62 li r0,__NR_syscalls
63 stw r0,0(r4)
Benjamin Herrenschmidt5d66da32005-11-16 13:54:32 +110064 crclr cr0*4+so
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 blr
66 .cfi_endproc
67V_FUNCTION_END(__kernel_get_syscall_map)
Benjamin Herrenschmidta7f290d2005-11-11 21:15:21 +110068
69/*
70 * void unsigned long long __kernel_get_tbfreq(void);
71 *
72 * returns the timebase frequency in HZ
73 */
74V_FUNCTION_BEGIN(__kernel_get_tbfreq)
75 .cfi_startproc
76 mflr r12
77 .cfi_register lr,r12
78 bl __get_datapage@local
Benjamin Herrenschmidta7f290d2005-11-11 21:15:21 +110079 lwz r4,(CFG_TB_TICKS_PER_SEC + 4)(r3)
Benjamin Herrenschmidt0c37ec22005-11-14 14:55:58 +110080 lwz r3,CFG_TB_TICKS_PER_SEC(r3)
Benjamin Herrenschmidta7f290d2005-11-11 21:15:21 +110081 mtlr r12
Benjamin Herrenschmidt5d66da32005-11-16 13:54:32 +110082 crclr cr0*4+so
Benjamin Herrenschmidt0c37ec22005-11-14 14:55:58 +110083 blr
Benjamin Herrenschmidta7f290d2005-11-11 21:15:21 +110084 .cfi_endproc
85V_FUNCTION_END(__kernel_get_tbfreq)