1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2015 Imagination Technologies
4 * Author: Alex Smith <alex.smith@imgtec.com>
9 #include <linux/compiler.h>
10 #include <linux/time.h>
12 #include <asm/clocksource.h>
14 #include <asm/unistd.h>
17 #ifdef CONFIG_MIPS_CLOCK_VSYSCALL
19 static __always_inline long gettimeofday_fallback(struct timeval *_tv,
22 register struct timezone *tz asm("a1") = _tz;
23 register struct timeval *tv asm("a0") = _tv;
24 register long ret asm("v0");
25 register long nr asm("v0") = __NR_gettimeofday;
26 register long error asm("a3");
30 : "=r" (ret), "=r" (error)
31 : "r" (tv), "r" (tz), "r" (nr)
32 : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
33 "$14", "$15", "$24", "$25", "hi", "lo", "memory");
35 return error ? -ret : ret;
40 static __always_inline long clock_gettime_fallback(clockid_t _clkid,
43 register struct timespec *ts asm("a1") = _ts;
44 register clockid_t clkid asm("a0") = _clkid;
45 register long ret asm("v0");
46 register long nr asm("v0") = __NR_clock_gettime;
47 register long error asm("a3");
51 : "=r" (ret), "=r" (error)
52 : "r" (clkid), "r" (ts), "r" (nr)
53 : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
54 "$14", "$15", "$24", "$25", "hi", "lo", "memory");
56 return error ? -ret : ret;
59 static __always_inline int do_realtime_coarse(struct timespec *ts,
60 const union mips_vdso_data *data)
65 start_seq = vdso_data_read_begin(data);
67 ts->tv_sec = data->xtime_sec;
68 ts->tv_nsec = data->xtime_nsec >> data->cs_shift;
69 } while (vdso_data_read_retry(data, start_seq));
74 static __always_inline int do_monotonic_coarse(struct timespec *ts,
75 const union mips_vdso_data *data)
82 start_seq = vdso_data_read_begin(data);
84 ts->tv_sec = data->xtime_sec;
85 ts->tv_nsec = data->xtime_nsec >> data->cs_shift;
87 to_mono_sec = data->wall_to_mono_sec;
88 to_mono_nsec = data->wall_to_mono_nsec;
89 } while (vdso_data_read_retry(data, start_seq));
91 ts->tv_sec += to_mono_sec;
92 timespec_add_ns(ts, to_mono_nsec);
97 #ifdef CONFIG_CSRC_R4K
99 static __always_inline u64 read_r4k_count(void)
103 __asm__ __volatile__(
115 #ifdef CONFIG_CLKSRC_MIPS_GIC
117 static __always_inline u64 read_gic_count(const union mips_vdso_data *data)
119 void __iomem *gic = get_gic(data);
123 hi = __raw_readl(gic + sizeof(lo));
124 lo = __raw_readl(gic);
125 hi2 = __raw_readl(gic + sizeof(lo));
128 return (((u64)hi) << 32) + lo;
133 static __always_inline u64 get_ns(const union mips_vdso_data *data)
135 u64 cycle_now, delta, nsec;
137 switch (data->clock_mode) {
138 #ifdef CONFIG_CSRC_R4K
140 cycle_now = read_r4k_count();
143 #ifdef CONFIG_CLKSRC_MIPS_GIC
145 cycle_now = read_gic_count(data);
152 delta = (cycle_now - data->cs_cycle_last) & data->cs_mask;
154 nsec = (delta * data->cs_mult) + data->xtime_nsec;
155 nsec >>= data->cs_shift;
160 static __always_inline int do_realtime(struct timespec *ts,
161 const union mips_vdso_data *data)
167 start_seq = vdso_data_read_begin(data);
169 if (data->clock_mode == VDSO_CLOCK_NONE)
172 ts->tv_sec = data->xtime_sec;
174 } while (vdso_data_read_retry(data, start_seq));
177 timespec_add_ns(ts, ns);
182 static __always_inline int do_monotonic(struct timespec *ts,
183 const union mips_vdso_data *data)
191 start_seq = vdso_data_read_begin(data);
193 if (data->clock_mode == VDSO_CLOCK_NONE)
196 ts->tv_sec = data->xtime_sec;
199 to_mono_sec = data->wall_to_mono_sec;
200 to_mono_nsec = data->wall_to_mono_nsec;
201 } while (vdso_data_read_retry(data, start_seq));
203 ts->tv_sec += to_mono_sec;
205 timespec_add_ns(ts, ns + to_mono_nsec);
210 #ifdef CONFIG_MIPS_CLOCK_VSYSCALL
213 * This is behind the ifdef so that we don't provide the symbol when there's no
214 * possibility of there being a usable clocksource, because there's nothing we
215 * can do without it. When libc fails the symbol lookup it should fall back on
216 * the standard syscall path.
218 int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
220 const union mips_vdso_data *data = get_vdso_data();
224 ret = do_realtime(&ts, data);
226 return gettimeofday_fallback(tv, tz);
229 tv->tv_sec = ts.tv_sec;
230 tv->tv_usec = ts.tv_nsec / 1000;
234 tz->tz_minuteswest = data->tz_minuteswest;
235 tz->tz_dsttime = data->tz_dsttime;
241 #endif /* CONFIG_MIPS_CLOCK_VSYSCALL */
243 int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts)
245 const union mips_vdso_data *data = get_vdso_data();
249 case CLOCK_REALTIME_COARSE:
250 ret = do_realtime_coarse(ts, data);
252 case CLOCK_MONOTONIC_COARSE:
253 ret = do_monotonic_coarse(ts, data);
256 ret = do_realtime(ts, data);
258 case CLOCK_MONOTONIC:
259 ret = do_monotonic(ts, data);
266 ret = clock_gettime_fallback(clkid, ts);