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 <asm/vdso/vdso.h>
17 #include <asm/clocksource.h>
18 #include <asm/unistd.h>
19 #include <asm/vdso.h>
20 
21 #define VDSO_HAS_CLOCK_GETRES		1
22 
23 #if MIPS_ISA_REV < 6
24 #define VDSO_SYSCALL_CLOBBERS "hi", "lo",
25 #else
26 #define VDSO_SYSCALL_CLOBBERS
27 #endif
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",
45 	  VDSO_SYSCALL_CLOBBERS
46 	  "memory");
47 
48 	return error ? -ret : ret;
49 }
50 
51 static __always_inline long clock_gettime_fallback(
52 					clockid_t _clkid,
53 					struct __kernel_timespec *_ts)
54 {
55 	register struct __kernel_timespec *ts asm("a1") = _ts;
56 	register clockid_t clkid asm("a0") = _clkid;
57 	register long ret asm("v0");
58 #if _MIPS_SIM == _MIPS_SIM_ABI64
59 	register long nr asm("v0") = __NR_clock_gettime;
60 #else
61 	register long nr asm("v0") = __NR_clock_gettime64;
62 #endif
63 	register long error asm("a3");
64 
65 	asm volatile(
66 	"       syscall\n"
67 	: "=r" (ret), "=r" (error)
68 	: "r" (clkid), "r" (ts), "r" (nr)
69 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
70 	  "$14", "$15", "$24", "$25",
71 	  VDSO_SYSCALL_CLOBBERS
72 	  "memory");
73 
74 	return error ? -ret : ret;
75 }
76 
77 static __always_inline int clock_getres_fallback(
78 					clockid_t _clkid,
79 					struct __kernel_timespec *_ts)
80 {
81 	register struct __kernel_timespec *ts asm("a1") = _ts;
82 	register clockid_t clkid asm("a0") = _clkid;
83 	register long ret asm("v0");
84 #if _MIPS_SIM == _MIPS_SIM_ABI64
85 	register long nr asm("v0") = __NR_clock_getres;
86 #else
87 	register long nr asm("v0") = __NR_clock_getres_time64;
88 #endif
89 	register long error asm("a3");
90 
91 	asm volatile(
92 	"       syscall\n"
93 	: "=r" (ret), "=r" (error)
94 	: "r" (clkid), "r" (ts), "r" (nr)
95 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
96 	  "$14", "$15", "$24", "$25",
97 	  VDSO_SYSCALL_CLOBBERS
98 	  "memory");
99 
100 	return error ? -ret : ret;
101 }
102 
103 #if _MIPS_SIM != _MIPS_SIM_ABI64
104 
105 static __always_inline long clock_gettime32_fallback(
106 					clockid_t _clkid,
107 					struct old_timespec32 *_ts)
108 {
109 	register struct old_timespec32 *ts asm("a1") = _ts;
110 	register clockid_t clkid asm("a0") = _clkid;
111 	register long ret asm("v0");
112 	register long nr asm("v0") = __NR_clock_gettime;
113 	register long error asm("a3");
114 
115 	asm volatile(
116 	"       syscall\n"
117 	: "=r" (ret), "=r" (error)
118 	: "r" (clkid), "r" (ts), "r" (nr)
119 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
120 	  "$14", "$15", "$24", "$25",
121 	  VDSO_SYSCALL_CLOBBERS
122 	  "memory");
123 
124 	return error ? -ret : ret;
125 }
126 
127 static __always_inline int clock_getres32_fallback(
128 					clockid_t _clkid,
129 					struct old_timespec32 *_ts)
130 {
131 	register struct old_timespec32 *ts asm("a1") = _ts;
132 	register clockid_t clkid asm("a0") = _clkid;
133 	register long ret asm("v0");
134 	register long nr asm("v0") = __NR_clock_getres;
135 	register long error asm("a3");
136 
137 	asm volatile(
138 	"       syscall\n"
139 	: "=r" (ret), "=r" (error)
140 	: "r" (clkid), "r" (ts), "r" (nr)
141 	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
142 	  "$14", "$15", "$24", "$25",
143 	  VDSO_SYSCALL_CLOBBERS
144 	  "memory");
145 
146 	return error ? -ret : ret;
147 }
148 #endif
149 
150 #ifdef CONFIG_CSRC_R4K
151 
152 static __always_inline u64 read_r4k_count(void)
153 {
154 	unsigned int count;
155 
156 	__asm__ __volatile__(
157 	"	.set push\n"
158 	"	.set mips32r2\n"
159 	"	rdhwr	%0, $2\n"
160 	"	.set pop\n"
161 	: "=r" (count));
162 
163 	return count;
164 }
165 
166 #endif
167 
168 #ifdef CONFIG_CLKSRC_MIPS_GIC
169 
170 static __always_inline u64 read_gic_count(const struct vdso_data *data)
171 {
172 	void __iomem *gic = get_gic(data);
173 	u32 hi, hi2, lo;
174 
175 	do {
176 		hi = __raw_readl(gic + sizeof(lo));
177 		lo = __raw_readl(gic);
178 		hi2 = __raw_readl(gic + sizeof(lo));
179 	} while (hi2 != hi);
180 
181 	return (((u64)hi) << 32) + lo;
182 }
183 
184 #endif
185 
186 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
187 						 const struct vdso_data *vd)
188 {
189 #ifdef CONFIG_CSRC_R4K
190 	if (clock_mode == VDSO_CLOCKMODE_R4K)
191 		return read_r4k_count();
192 #endif
193 #ifdef CONFIG_CLKSRC_MIPS_GIC
194 	if (clock_mode == VDSO_CLOCKMODE_GIC)
195 		return read_gic_count(vd);
196 #endif
197 	/*
198 	 * Core checks mode already. So this raced against a concurrent
199 	 * update. Return something. Core will do another round see the
200 	 * change and fallback to syscall.
201 	 */
202 	return 0;
203 }
204 
205 static inline bool mips_vdso_hres_capable(void)
206 {
207 	return IS_ENABLED(CONFIG_CSRC_R4K) ||
208 	       IS_ENABLED(CONFIG_CLKSRC_MIPS_GIC);
209 }
210 #define __arch_vdso_hres_capable mips_vdso_hres_capable
211 
212 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
213 {
214 	return get_vdso_data();
215 }
216 
217 #endif /* !__ASSEMBLY__ */
218 
219 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */
220