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
29static __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
51static __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
77static __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
105static __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
127static __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
152static __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
170static __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
186static __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
205static 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
212static __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