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 static __always_inline long gettimeofday_fallback(
30 				struct __kernel_old_timeval *_tv,
31 				struct timezone *_tz)
32 {
33 	register struct timezone *tz asm("a1") = _tz;
34 	register struct __kernel_old_timeval *tv asm("a0") = _tv;
35 	register long ret asm("v0");
36 	register long nr asm("v0") = __NR_gettimeofday;
37 	register long error asm("a3");
38 
39 	asm volatile(
40 	"       syscall\n"
41 	: "=r" (ret), "=r" (error)
42 	: "r" (tv), "r" (tz), "r" (nr)
43 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
44 	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
45 
46 	return error ? -ret : ret;
47 }
48 
49 static __always_inline long clock_gettime_fallback(
50 					clockid_t _clkid,
51 					struct __kernel_timespec *_ts)
52 {
53 	register struct __kernel_timespec *ts asm("a1") = _ts;
54 	register clockid_t clkid asm("a0") = _clkid;
55 	register long ret asm("v0");
56 #if _MIPS_SIM == _MIPS_SIM_ABI64
57 	register long nr asm("v0") = __NR_clock_gettime;
58 #else
59 	register long nr asm("v0") = __NR_clock_gettime64;
60 #endif
61 	register long error asm("a3");
62 
63 	asm volatile(
64 	"       syscall\n"
65 	: "=r" (ret), "=r" (error)
66 	: "r" (clkid), "r" (ts), "r" (nr)
67 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
68 	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
69 
70 	return error ? -ret : ret;
71 }
72 
73 static __always_inline int clock_getres_fallback(
74 					clockid_t _clkid,
75 					struct __kernel_timespec *_ts)
76 {
77 	register struct __kernel_timespec *ts asm("a1") = _ts;
78 	register clockid_t clkid asm("a0") = _clkid;
79 	register long ret asm("v0");
80 #if _MIPS_SIM == _MIPS_SIM_ABI64
81 	register long nr asm("v0") = __NR_clock_getres;
82 #else
83 	register long nr asm("v0") = __NR_clock_getres_time64;
84 #endif
85 	register long error asm("a3");
86 
87 	asm volatile(
88 	"       syscall\n"
89 	: "=r" (ret), "=r" (error)
90 	: "r" (clkid), "r" (ts), "r" (nr)
91 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
92 	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
93 
94 	return error ? -ret : ret;
95 }
96 
97 #if _MIPS_SIM != _MIPS_SIM_ABI64
98 
99 #define VDSO_HAS_32BIT_FALLBACK	1
100 
101 static __always_inline long clock_gettime32_fallback(
102 					clockid_t _clkid,
103 					struct old_timespec32 *_ts)
104 {
105 	register struct old_timespec32 *ts asm("a1") = _ts;
106 	register clockid_t clkid asm("a0") = _clkid;
107 	register long ret asm("v0");
108 	register long nr asm("v0") = __NR_clock_gettime;
109 	register long error asm("a3");
110 
111 	asm volatile(
112 	"       syscall\n"
113 	: "=r" (ret), "=r" (error)
114 	: "r" (clkid), "r" (ts), "r" (nr)
115 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
116 	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
117 
118 	return error ? -ret : ret;
119 }
120 
121 static __always_inline int clock_getres32_fallback(
122 					clockid_t _clkid,
123 					struct old_timespec32 *_ts)
124 {
125 	register struct old_timespec32 *ts asm("a1") = _ts;
126 	register clockid_t clkid asm("a0") = _clkid;
127 	register long ret asm("v0");
128 	register long nr asm("v0") = __NR_clock_getres;
129 	register long error asm("a3");
130 
131 	asm volatile(
132 	"       syscall\n"
133 	: "=r" (ret), "=r" (error)
134 	: "r" (clkid), "r" (ts), "r" (nr)
135 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
136 	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
137 
138 	return error ? -ret : ret;
139 }
140 #endif
141 
142 #ifdef CONFIG_CSRC_R4K
143 
144 static __always_inline u64 read_r4k_count(void)
145 {
146 	unsigned int count;
147 
148 	__asm__ __volatile__(
149 	"	.set push\n"
150 	"	.set mips32r2\n"
151 	"	rdhwr	%0, $2\n"
152 	"	.set pop\n"
153 	: "=r" (count));
154 
155 	return count;
156 }
157 
158 #endif
159 
160 #ifdef CONFIG_CLKSRC_MIPS_GIC
161 
162 static __always_inline u64 read_gic_count(const struct vdso_data *data)
163 {
164 	void __iomem *gic = get_gic(data);
165 	u32 hi, hi2, lo;
166 
167 	do {
168 		hi = __raw_readl(gic + sizeof(lo));
169 		lo = __raw_readl(gic);
170 		hi2 = __raw_readl(gic + sizeof(lo));
171 	} while (hi2 != hi);
172 
173 	return (((u64)hi) << 32) + lo;
174 }
175 
176 #endif
177 
178 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
179 {
180 #ifdef CONFIG_CLKSRC_MIPS_GIC
181 	const struct vdso_data *data = get_vdso_data();
182 #endif
183 	u64 cycle_now;
184 
185 	switch (clock_mode) {
186 #ifdef CONFIG_CSRC_R4K
187 	case VDSO_CLOCK_R4K:
188 		cycle_now = read_r4k_count();
189 		break;
190 #endif
191 #ifdef CONFIG_CLKSRC_MIPS_GIC
192 	case VDSO_CLOCK_GIC:
193 		cycle_now = read_gic_count(data);
194 		break;
195 #endif
196 	default:
197 		cycle_now = __VDSO_USE_SYSCALL;
198 		break;
199 	}
200 
201 	return cycle_now;
202 }
203 
204 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
205 {
206 	return get_vdso_data();
207 }
208 
209 #endif /* !__ASSEMBLY__ */
210 
211 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */
212