xref: /linux/arch/riscv/include/asm/vdso/gettimeofday.h (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_VDSO_GETTIMEOFDAY_H
3 #define __ASM_VDSO_GETTIMEOFDAY_H
4 
5 #ifndef __ASSEMBLY__
6 
7 #include <asm/barrier.h>
8 #include <asm/unistd.h>
9 #include <asm/csr.h>
10 #include <uapi/linux/time.h>
11 
12 /*
13  * 32-bit land is lacking generic time vsyscalls as well as the legacy 32-bit
14  * time syscalls like gettimeofday. Skip these definitions since on 32-bit.
15  */
16 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
17 
18 #define VDSO_HAS_CLOCK_GETRES	1
19 
20 static __always_inline
21 int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
22 			  struct timezone *_tz)
23 {
24 	register struct __kernel_old_timeval *tv asm("a0") = _tv;
25 	register struct timezone *tz asm("a1") = _tz;
26 	register long ret asm("a0");
27 	register long nr asm("a7") = __NR_gettimeofday;
28 
29 	asm volatile ("ecall\n"
30 		      : "=r" (ret)
31 		      : "r"(tv), "r"(tz), "r"(nr)
32 		      : "memory");
33 
34 	return ret;
35 }
36 
37 static __always_inline
38 long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
39 {
40 	register clockid_t clkid asm("a0") = _clkid;
41 	register struct __kernel_timespec *ts asm("a1") = _ts;
42 	register long ret asm("a0");
43 	register long nr asm("a7") = __NR_clock_gettime;
44 
45 	asm volatile ("ecall\n"
46 		      : "=r" (ret)
47 		      : "r"(clkid), "r"(ts), "r"(nr)
48 		      : "memory");
49 
50 	return ret;
51 }
52 
53 static __always_inline
54 int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
55 {
56 	register clockid_t clkid asm("a0") = _clkid;
57 	register struct __kernel_timespec *ts asm("a1") = _ts;
58 	register long ret asm("a0");
59 	register long nr asm("a7") = __NR_clock_getres;
60 
61 	asm volatile ("ecall\n"
62 		      : "=r" (ret)
63 		      : "r"(clkid), "r"(ts), "r"(nr)
64 		      : "memory");
65 
66 	return ret;
67 }
68 
69 #endif /* CONFIG_GENERIC_TIME_VSYSCALL */
70 
71 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
72 						 const struct vdso_data *vd)
73 {
74 	/*
75 	 * The purpose of csr_read(CSR_TIME) is to trap the system into
76 	 * M-mode to obtain the value of CSR_TIME. Hence, unlike other
77 	 * architecture, no fence instructions surround the csr_read()
78 	 */
79 	return csr_read(CSR_TIME);
80 }
81 
82 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
83 {
84 	return _vdso_data;
85 }
86 
87 #ifdef CONFIG_TIME_NS
88 static __always_inline
89 const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
90 {
91 	return _timens_data;
92 }
93 #endif
94 #endif /* !__ASSEMBLY__ */
95 
96 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */
97