linux/arch/arm/include/asm/arch_timer.h
Marc Zyngier 5ef19a161c clocksource/arm_arch_timer: Direcly assign set_next_event workaround
When a given timer is affected by an erratum and requires an
alternative implementation of set_next_event, we do a rather
complicated dance to detect and call the workaround on each
set_next_event call.

This is clearly idiotic, as we can perfectly detect whether
this CPU requires a workaround while setting up the clock event
device.

This only requires the CPU-specific detection to be done a bit
earlier, and we can then safely override the set_next_event pointer
if we have a workaround associated to that CPU.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by; Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30 16:10:57 +01:00

119 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASMARM_ARCH_TIMER_H
#define __ASMARM_ARCH_TIMER_H
#include <asm/barrier.h>
#include <asm/errno.h>
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/types.h>
#include <clocksource/arm_arch_timer.h>
#ifdef CONFIG_ARM_ARCH_TIMER
/* 32bit ARM doesn't know anything about timer errata... */
#define has_erratum_handler(h) (false)
#define erratum_handler(h) (arch_timer_##h)
int arch_timer_arch_init(void);
/*
* 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. At least it does so with a recent GCC (4.6.3).
*/
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:
asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
break;
}
} else if (access == ARCH_TIMER_VIRT_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
break;
}
}
isb();
}
static __always_inline
u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg)
{
u32 val = 0;
if (access == ARCH_TIMER_PHYS_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
break;
}
} else if (access == ARCH_TIMER_VIRT_ACCESS) {
switch (reg) {
case ARCH_TIMER_REG_CTRL:
asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
break;
case ARCH_TIMER_REG_TVAL:
asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
break;
}
}
return val;
}
static inline u32 arch_timer_get_cntfrq(void)
{
u32 val;
asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
return val;
}
static inline u64 arch_counter_get_cntpct(void)
{
u64 cval;
isb();
asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval));
return cval;
}
static inline u64 arch_counter_get_cntvct(void)
{
u64 cval;
isb();
asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
return cval;
}
static inline u32 arch_timer_get_cntkctl(void)
{
u32 cntkctl;
asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
return cntkctl;
}
static inline void arch_timer_set_cntkctl(u32 cntkctl)
{
asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
isb();
}
#endif
#endif