2 * Copyright (C) 2015 Imagination Technologies
3 * Author: Alex Smith <alex.smith@imgtec.com>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
13 #include <linux/compiler.h>
14 #include <linux/irqchip/mips-gic.h>
15 #include <linux/time.h>
17 #include <asm/clocksource.h>
19 #include <asm/mips-cm.h>
20 #include <asm/unistd.h>
23 static __always_inline int do_realtime_coarse(struct timespec *ts,
24 const union mips_vdso_data *data)
29 start_seq = vdso_data_read_begin(data);
31 ts->tv_sec = data->xtime_sec;
32 ts->tv_nsec = data->xtime_nsec >> data->cs_shift;
33 } while (vdso_data_read_retry(data, start_seq));
38 static __always_inline int do_monotonic_coarse(struct timespec *ts,
39 const union mips_vdso_data *data)
46 start_seq = vdso_data_read_begin(data);
48 ts->tv_sec = data->xtime_sec;
49 ts->tv_nsec = data->xtime_nsec >> data->cs_shift;
51 to_mono_sec = data->wall_to_mono_sec;
52 to_mono_nsec = data->wall_to_mono_nsec;
53 } while (vdso_data_read_retry(data, start_seq));
55 ts->tv_sec += to_mono_sec;
56 timespec_add_ns(ts, to_mono_nsec);
61 #ifdef CONFIG_CSRC_R4K
63 static __always_inline u64 read_r4k_count(void)
79 #ifdef CONFIG_CLKSRC_MIPS_GIC
81 static __always_inline u64 read_gic_count(const union mips_vdso_data *data)
83 void __iomem *gic = get_gic(data);
87 hi = __raw_readl(gic + GIC_UMV_SH_COUNTER_63_32_OFS);
88 lo = __raw_readl(gic + GIC_UMV_SH_COUNTER_31_00_OFS);
89 hi2 = __raw_readl(gic + GIC_UMV_SH_COUNTER_63_32_OFS);
92 return (((u64)hi) << 32) + lo;
97 static __always_inline u64 get_ns(const union mips_vdso_data *data)
99 u64 cycle_now, delta, nsec;
101 switch (data->clock_mode) {
102 #ifdef CONFIG_CSRC_R4K
104 cycle_now = read_r4k_count();
107 #ifdef CONFIG_CLKSRC_MIPS_GIC
109 cycle_now = read_gic_count(data);
116 delta = (cycle_now - data->cs_cycle_last) & data->cs_mask;
118 nsec = (delta * data->cs_mult) + data->xtime_nsec;
119 nsec >>= data->cs_shift;
124 static __always_inline int do_realtime(struct timespec *ts,
125 const union mips_vdso_data *data)
131 start_seq = vdso_data_read_begin(data);
133 if (data->clock_mode == VDSO_CLOCK_NONE)
136 ts->tv_sec = data->xtime_sec;
138 } while (vdso_data_read_retry(data, start_seq));
141 timespec_add_ns(ts, ns);
146 static __always_inline int do_monotonic(struct timespec *ts,
147 const union mips_vdso_data *data)
155 start_seq = vdso_data_read_begin(data);
157 if (data->clock_mode == VDSO_CLOCK_NONE)
160 ts->tv_sec = data->xtime_sec;
163 to_mono_sec = data->wall_to_mono_sec;
164 to_mono_nsec = data->wall_to_mono_nsec;
165 } while (vdso_data_read_retry(data, start_seq));
167 ts->tv_sec += to_mono_sec;
169 timespec_add_ns(ts, ns + to_mono_nsec);
174 #ifdef CONFIG_MIPS_CLOCK_VSYSCALL
177 * This is behind the ifdef so that we don't provide the symbol when there's no
178 * possibility of there being a usable clocksource, because there's nothing we
179 * can do without it. When libc fails the symbol lookup it should fall back on
180 * the standard syscall path.
182 int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
184 const union mips_vdso_data *data = get_vdso_data();
188 ret = do_realtime(&ts, data);
193 tv->tv_sec = ts.tv_sec;
194 tv->tv_usec = ts.tv_nsec / 1000;
198 tz->tz_minuteswest = data->tz_minuteswest;
199 tz->tz_dsttime = data->tz_dsttime;
205 #endif /* CONFIG_CLKSRC_MIPS_GIC */
207 int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts)
209 const union mips_vdso_data *data = get_vdso_data();
213 case CLOCK_REALTIME_COARSE:
214 ret = do_realtime_coarse(ts, data);
216 case CLOCK_MONOTONIC_COARSE:
217 ret = do_monotonic_coarse(ts, data);
220 ret = do_realtime(ts, data);
222 case CLOCK_MONOTONIC:
223 ret = do_monotonic(ts, data);
230 /* If we return -ENOSYS libc should fall back to a syscall. */