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 #define VDSO_HAS_CLOCK_GETRES	1
13 
14 static __always_inline
15 int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
16 			  struct timezone *_tz)
17 {
18 	register struct __kernel_old_timeval *tv asm("a0") = _tv;
19 	register struct timezone *tz asm("a1") = _tz;
20 	register long ret asm("a0");
21 	register long nr asm("a7") = __NR_gettimeofday;
22 
23 	asm volatile ("ecall\n"
24 		      : "=r" (ret)
25 		      : "r"(tv), "r"(tz), "r"(nr)
26 		      : "memory");
27 
28 	return ret;
29 }
30 
31 static __always_inline
32 long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
33 {
34 	register clockid_t clkid asm("a0") = _clkid;
35 	register struct __kernel_timespec *ts asm("a1") = _ts;
36 	register long ret asm("a0");
37 	register long nr asm("a7") = __NR_clock_gettime;
38 
39 	asm volatile ("ecall\n"
40 		      : "=r" (ret)
41 		      : "r"(clkid), "r"(ts), "r"(nr)
42 		      : "memory");
43 
44 	return ret;
45 }
46 
47 static __always_inline
48 int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
49 {
50 	register clockid_t clkid asm("a0") = _clkid;
51 	register struct __kernel_timespec *ts asm("a1") = _ts;
52 	register long ret asm("a0");
53 	register long nr asm("a7") = __NR_clock_getres;
54 
55 	asm volatile ("ecall\n"
56 		      : "=r" (ret)
57 		      : "r"(clkid), "r"(ts), "r"(nr)
58 		      : "memory");
59 
60 	return ret;
61 }
62 
63 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
64 						 const struct vdso_data *vd)
65 {
66 	/*
67 	 * The purpose of csr_read(CSR_TIME) is to trap the system into
68 	 * M-mode to obtain the value of CSR_TIME. Hence, unlike other
69 	 * architecture, no fence instructions surround the csr_read()
70 	 */
71 	return csr_read(CSR_TIME);
72 }
73 
74 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
75 {
76 	return _vdso_data;
77 }
78 
79 #endif /* !__ASSEMBLY__ */
80 
81 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */
82