summaryrefslogtreecommitdiff
path: root/arch/arm64/include/asm/arch_timer.h
blob: b4b34004a21e2a8ee9514d55f1cd0b90db70bc03 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/*
 * arch/arm64/include/asm/arch_timer.h
 *
 * Copyright (C) 2012 ARM Ltd.
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASM_ARCH_TIMER_H
#define __ASM_ARCH_TIMER_H

#include <asm/barrier.h>
#include <asm/sysreg.h>

#include <linux/bug.h>
#include <linux/init.h>
#include <linux/jump_label.h>
#include <linux/types.h>

#include <clocksource/arm_arch_timer.h>

#if IS_ENABLED(CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND)
extern struct static_key_false arch_timer_read_ool_enabled;
#define needs_unstable_timer_counter_workaround() \
	static_branch_unlikely(&arch_timer_read_ool_enabled)
#else
#define needs_unstable_timer_counter_workaround()  false
#endif


struct arch_timer_erratum_workaround {
	const char *id;		/* Indicate the Erratum ID */
	u32 (*read_cntp_tval_el0)(void);
	u32 (*read_cntv_tval_el0)(void);
	u64 (*read_cntvct_el0)(void);
};

extern const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround;

#define arch_timer_reg_read_stable(reg) 		\
({							\
	u64 _val;					\
	if (needs_unstable_timer_counter_workaround())		\
		_val = timer_unstable_counter_workaround->read_##reg();\
	else						\
		_val = read_sysreg(reg);		\
	_val;						\
})

/*
 * These register accessors are marked inline so the compiler can
 * nicely work out which register we want, and chuck away the rest of
 * the code.
 */
static __always_inline
void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val)
{
	if (access == ARCH_TIMER_PHYS_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			write_sysreg(val, cntp_ctl_el0);
			break;
		case ARCH_TIMER_REG_TVAL:
			write_sysreg(val, cntp_tval_el0);
			break;
		}
	} else if (access == ARCH_TIMER_VIRT_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			write_sysreg(val, cntv_ctl_el0);
			break;
		case ARCH_TIMER_REG_TVAL:
			write_sysreg(val, cntv_tval_el0);
			break;
		}
	}

	isb();
}

static __always_inline
u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg)
{
	if (access == ARCH_TIMER_PHYS_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			return read_sysreg(cntp_ctl_el0);
		case ARCH_TIMER_REG_TVAL:
			return arch_timer_reg_read_stable(cntp_tval_el0);
		}
	} else if (access == ARCH_TIMER_VIRT_ACCESS) {
		switch (reg) {
		case ARCH_TIMER_REG_CTRL:
			return read_sysreg(cntv_ctl_el0);
		case ARCH_TIMER_REG_TVAL:
			return arch_timer_reg_read_stable(cntv_tval_el0);
		}
	}

	BUG();
}

static inline u32 arch_timer_get_cntfrq(void)
{
	return read_sysreg(cntfrq_el0);
}

static inline u32 arch_timer_get_cntkctl(void)
{
	return read_sysreg(cntkctl_el1);
}

static inline void arch_timer_set_cntkctl(u32 cntkctl)
{
	write_sysreg(cntkctl, cntkctl_el1);
}

static inline u64 arch_counter_get_cntpct(void)
{
	/*
	 * AArch64 kernel and user space mandate the use of CNTVCT.
	 */
	BUG();
	return 0;
}

static inline u64 arch_counter_get_cntvct(void)
{
	isb();
	return arch_timer_reg_read_stable(cntvct_el0);
}

static inline int arch_timer_arch_init(void)
{
	return 0;
}

#endif