1/*
  2 * Copyright (C) 2018 ARM Limited
  3 * Copyright (C) 2015 Imagination Technologies
  4 * Author: Alex Smith <alex.smith@imgtec.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify it
  7 * under the terms of the GNU General Public License as published by the
  8 * Free Software Foundation;  either version 2 of the  License, or (at your
  9 * option) any later version.
 10 */
 11#ifndef __ASM_VDSO_GETTIMEOFDAY_H
 12#define __ASM_VDSO_GETTIMEOFDAY_H
 13
 14#ifndef __ASSEMBLY__
 15
 16#include <linux/compiler.h>
 17#include <linux/time.h>
 18
 19#include <asm/vdso/vdso.h>
 20#include <asm/clocksource.h>
 21#include <asm/io.h>
 22#include <asm/unistd.h>
 23#include <asm/vdso.h>
 24
 25#define VDSO_HAS_CLOCK_GETRES		1
 26
 27#define __VDSO_USE_SYSCALL		ULLONG_MAX
 28
 29#ifdef CONFIG_MIPS_CLOCK_VSYSCALL
 30
 31static __always_inline long gettimeofday_fallback(
 32				struct __kernel_old_timeval *_tv,
 33				struct timezone *_tz)
 34{
 35	register struct timezone *tz asm("a1") = _tz;
 36	register struct __kernel_old_timeval *tv asm("a0") = _tv;
 37	register long ret asm("v0");
 38	register long nr asm("v0") = __NR_gettimeofday;
 39	register long error asm("a3");
 40
 41	asm volatile(
 42	"       syscall\n"
 43	: "=r" (ret), "=r" (error)
 44	: "r" (tv), "r" (tz), "r" (nr)
 45	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
 46	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
 47
 48	return error ? -ret : ret;
 49}
 50
 51#else
 52
 53static __always_inline long gettimeofday_fallback(
 54				struct __kernel_old_timeval *_tv,
 55				struct timezone *_tz)
 56{
 57	return -1;
 58}
 59
 60#endif
 61
 62static __always_inline long clock_gettime_fallback(
 63					clockid_t _clkid,
 64					struct __kernel_timespec *_ts)
 65{
 66	register struct __kernel_timespec *ts asm("a1") = _ts;
 67	register clockid_t clkid asm("a0") = _clkid;
 68	register long ret asm("v0");
 69#if _MIPS_SIM == _MIPS_SIM_ABI64
 70	register long nr asm("v0") = __NR_clock_gettime;
 71#else
 72	register long nr asm("v0") = __NR_clock_gettime64;
 73#endif
 74	register long error asm("a3");
 75
 76	asm volatile(
 77	"       syscall\n"
 78	: "=r" (ret), "=r" (error)
 79	: "r" (clkid), "r" (ts), "r" (nr)
 80	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
 81	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
 82
 83	return error ? -ret : ret;
 84}
 85
 86static __always_inline int clock_getres_fallback(
 87					clockid_t _clkid,
 88					struct __kernel_timespec *_ts)
 89{
 90	register struct __kernel_timespec *ts asm("a1") = _ts;
 91	register clockid_t clkid asm("a0") = _clkid;
 92	register long ret asm("v0");
 93#if _MIPS_SIM == _MIPS_SIM_ABI64
 94	register long nr asm("v0") = __NR_clock_getres;
 95#else
 96	register long nr asm("v0") = __NR_clock_getres_time64;
 97#endif
 98	register long error asm("a3");
 99
100	asm volatile(
101	"       syscall\n"
102	: "=r" (ret), "=r" (error)
103	: "r" (clkid), "r" (ts), "r" (nr)
104	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
105	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
106
107	return error ? -ret : ret;
108}
109
110#if _MIPS_SIM != _MIPS_SIM_ABI64
111
112#define VDSO_HAS_32BIT_FALLBACK	1
113
114static __always_inline long clock_gettime32_fallback(
115					clockid_t _clkid,
116					struct old_timespec32 *_ts)
117{
118	register struct old_timespec32 *ts asm("a1") = _ts;
119	register clockid_t clkid asm("a0") = _clkid;
120	register long ret asm("v0");
121	register long nr asm("v0") = __NR_clock_gettime;
122	register long error asm("a3");
123
124	asm volatile(
125	"       syscall\n"
126	: "=r" (ret), "=r" (error)
127	: "r" (clkid), "r" (ts), "r" (nr)
128	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
129	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
130
131	return error ? -ret : ret;
132}
133
134static __always_inline int clock_getres32_fallback(
135					clockid_t _clkid,
136					struct old_timespec32 *_ts)
137{
138	register struct old_timespec32 *ts asm("a1") = _ts;
139	register clockid_t clkid asm("a0") = _clkid;
140	register long ret asm("v0");
141	register long nr asm("v0") = __NR_clock_getres;
142	register long error asm("a3");
143
144	asm volatile(
145	"       syscall\n"
146	: "=r" (ret), "=r" (error)
147	: "r" (clkid), "r" (ts), "r" (nr)
148	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
149	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
150
151	return error ? -ret : ret;
152}
153#endif
154
155#ifdef CONFIG_CSRC_R4K
156
157static __always_inline u64 read_r4k_count(void)
158{
159	unsigned int count;
160
161	__asm__ __volatile__(
162	"	.set push\n"
163	"	.set mips32r2\n"
164	"	rdhwr	%0, $2\n"
165	"	.set pop\n"
166	: "=r" (count));
167
168	return count;
169}
170
171#endif
172
173#ifdef CONFIG_CLKSRC_MIPS_GIC
174
175static __always_inline u64 read_gic_count(const struct vdso_data *data)
176{
177	void __iomem *gic = get_gic(data);
178	u32 hi, hi2, lo;
179
180	do {
181		hi = __raw_readl(gic + sizeof(lo));
182		lo = __raw_readl(gic);
183		hi2 = __raw_readl(gic + sizeof(lo));
184	} while (hi2 != hi);
185
186	return (((u64)hi) << 32) + lo;
187}
188
189#endif
190
191static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
192{
193#ifdef CONFIG_CLKSRC_MIPS_GIC
194	const struct vdso_data *data = get_vdso_data();
195#endif
196	u64 cycle_now;
197
198	switch (clock_mode) {
199#ifdef CONFIG_CSRC_R4K
200	case VDSO_CLOCK_R4K:
201		cycle_now = read_r4k_count();
202		break;
203#endif
204#ifdef CONFIG_CLKSRC_MIPS_GIC
205	case VDSO_CLOCK_GIC:
206		cycle_now = read_gic_count(data);
207		break;
208#endif
209	default:
210		cycle_now = __VDSO_USE_SYSCALL;
211		break;
212	}
213
214	return cycle_now;
215}
216
217static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
218{
219	return get_vdso_data();
220}
221
222#endif /* !__ASSEMBLY__ */
223
224#endif /* __ASM_VDSO_GETTIMEOFDAY_H */