1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Userland implementation of gettimeofday() for processes
4 * for use in the vDSO
5 *
6 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org,
7 * IBM Corp.
8 */
9#include <asm/processor.h>
10#include <asm/ppc_asm.h>
11#include <asm/vdso.h>
12#include <asm/vdso_datapage.h>
13#include <asm/asm-offsets.h>
14#include <asm/unistd.h>
15
16/*
17 * The macro sets two stack frames, one for the caller and one for the callee
18 * because there are no requirement for the caller to set a stack frame when
19 * calling VDSO so it may have omitted to set one, especially on PPC64
20 */
21
22.macro cvdso_call funct call_time=0
23 .cfi_startproc
24 PPC_STLU r1, -PPC_MIN_STKFRM(r1)
25 .cfi_adjust_cfa_offset PPC_MIN_STKFRM
26 mflr r0
27 PPC_STLU r1, -PPC_MIN_STKFRM(r1)
28 .cfi_adjust_cfa_offset PPC_MIN_STKFRM
29 PPC_STL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
30 .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF
31#ifdef __powerpc64__
32 PPC_STL r2, PPC_MIN_STKFRM + STK_GOT(r1)
33 .cfi_rel_offset r2, PPC_MIN_STKFRM + STK_GOT
34#endif
35 get_datapage r5
36 .ifeq \call_time
37 addi r5, r5, VDSO_DATA_OFFSET
38 .else
39 addi r4, r5, VDSO_DATA_OFFSET
40 .endif
41#ifdef __powerpc64__
42 bl CFUNC(DOTSYM(\funct))
43#else
44 bl \funct
45#endif
46 PPC_LL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
47#ifdef __powerpc64__
48 PPC_LL r2, PPC_MIN_STKFRM + STK_GOT(r1)
49 .cfi_restore r2
50#endif
51 .ifeq \call_time
52 cmpwi r3, 0
53 .endif
54 mtlr r0
55 addi r1, r1, 2 * PPC_MIN_STKFRM
56 .cfi_restore lr
57 .cfi_def_cfa_offset 0
58 crclr so
59 .ifeq \call_time
60 beqlr+
61 crset so
62 neg r3, r3
63 .endif
64 blr
65 .cfi_endproc
66.endm
67
68 .text
69/*
70 * Exact prototype of gettimeofday
71 *
72 * int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz);
73 *
74 */
75V_FUNCTION_BEGIN(__kernel_gettimeofday)
76 cvdso_call __c_kernel_gettimeofday
77V_FUNCTION_END(__kernel_gettimeofday)
78
79/*
80 * Exact prototype of clock_gettime()
81 *
82 * int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp);
83 *
84 */
85V_FUNCTION_BEGIN(__kernel_clock_gettime)
86 cvdso_call __c_kernel_clock_gettime
87V_FUNCTION_END(__kernel_clock_gettime)
88
89/*
90 * Exact prototype of clock_gettime64()
91 *
92 * int __kernel_clock_gettime64(clockid_t clock_id, struct __timespec64 *ts);
93 *
94 */
95#ifndef __powerpc64__
96V_FUNCTION_BEGIN(__kernel_clock_gettime64)
97 cvdso_call __c_kernel_clock_gettime64
98V_FUNCTION_END(__kernel_clock_gettime64)
99#endif
100
101/*
102 * Exact prototype of clock_getres()
103 *
104 * int __kernel_clock_getres(clockid_t clock_id, struct timespec *res);
105 *
106 */
107V_FUNCTION_BEGIN(__kernel_clock_getres)
108 cvdso_call __c_kernel_clock_getres
109V_FUNCTION_END(__kernel_clock_getres)
110
111
112/*
113 * Exact prototype of time()
114 *
115 * time_t time(time *t);
116 *
117 */
118V_FUNCTION_BEGIN(__kernel_time)
119 cvdso_call __c_kernel_time call_time=1
120V_FUNCTION_END(__kernel_time)
121
122/* Routines for restoring integer registers, called by the compiler. */
123/* Called with r11 pointing to the stack header word of the caller of the */
124/* function, just beyond the end of the integer restore area. */
125#ifndef __powerpc64__
126_GLOBAL(_restgpr_31_x)
127_GLOBAL(_rest32gpr_31_x)
128 lwz r0,4(r11)
129 lwz r31,-4(r11)
130 mtlr r0
131 mr r1,r11
132 blr
133#endif
134

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