1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Access to the shared data page by the vDSO & syscall map
4 *
5 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
6 */
7
8#include <asm/processor.h>
9#include <asm/ppc_asm.h>
10#include <asm/asm-offsets.h>
11#include <asm/unistd.h>
12#include <asm/vdso.h>
13#include <asm/vdso_datapage.h>
14
15 .text
16
17/*
18 * void *__kernel_get_syscall_map(unsigned int *syscall_count) ;
19 *
20 * returns a pointer to the syscall map. the map is agnostic to the
21 * size of "long", unlike kernel bitops, it stores bits from top to
22 * bottom so that memory actually contains a linear bitmap
23 * check for syscall N by testing bit (0x80000000 >> (N & 0x1f)) of
24 * 32 bits int at N >> 5.
25 */
26V_FUNCTION_BEGIN(__kernel_get_syscall_map)
27 .cfi_startproc
28 mflr r12
29 .cfi_register lr,r12
30 mr. r4,r3
31 get_datapage r3 vdso_u_arch_data
32 mtlr r12
33#ifdef __powerpc64__
34 addi r3,r3,CFG_SYSCALL_MAP64
35#else
36 addi r3,r3,CFG_SYSCALL_MAP32
37#endif
38 crclr cr0*4+so
39 beqlr
40 li r0,NR_syscalls
41 stw r0,0(r4)
42 blr
43 .cfi_endproc
44V_FUNCTION_END(__kernel_get_syscall_map)
45
46/*
47 * void unsigned long long __kernel_get_tbfreq(void);
48 *
49 * returns the timebase frequency in HZ
50 */
51V_FUNCTION_BEGIN(__kernel_get_tbfreq)
52 .cfi_startproc
53 mflr r12
54 .cfi_register lr,r12
55 get_datapage r3 vdso_u_arch_data
56#ifndef __powerpc64__
57 lwz r4,(CFG_TB_TICKS_PER_SEC + 4)(r3)
58#endif
59 PPC_LL r3,CFG_TB_TICKS_PER_SEC(r3)
60 mtlr r12
61 crclr cr0*4+so
62 blr
63 .cfi_endproc
64V_FUNCTION_END(__kernel_get_tbfreq)
65

source code of linux/arch/powerpc/kernel/vdso/datapage.S