Loading...
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 | /*
* 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_FSL_ERRATUM_A008585)
extern struct static_key_false arch_timer_read_ool_enabled;
#define needs_fsl_a008585_workaround() \
static_branch_unlikely(&arch_timer_read_ool_enabled)
#else
#define needs_fsl_a008585_workaround() false
#endif
u32 __fsl_a008585_read_cntp_tval_el0(void);
u32 __fsl_a008585_read_cntv_tval_el0(void);
u64 __fsl_a008585_read_cntvct_el0(void);
/*
* The number of retries is an arbitrary value well beyond the highest number
* of iterations the loop has been observed to take.
*/
#define __fsl_a008585_read_reg(reg) ({ \
u64 _old, _new; \
int _retries = 200; \
\
do { \
_old = read_sysreg(reg); \
_new = read_sysreg(reg); \
_retries--; \
} while (unlikely(_old != _new) && _retries); \
\
WARN_ON_ONCE(!_retries); \
_new; \
})
#define arch_timer_reg_read_stable(reg) \
({ \
u64 _val; \
if (needs_fsl_a008585_workaround()) \
_val = __fsl_a008585_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
|