From a38b71b0833eb2fabd2b1fa37d665c0a88b8b7e4 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sun, 17 Oct 2021 13:42:12 +0100 Subject: clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL In order to cope better with high frequency counters, move the programming of the timers from the countdown timer (TVAL) over to the comparator (CVAL). The programming model is slightly different, as we now need to read the current counter value to have an absolute deadline instead of a relative one. There is a small overhead to this change, which we will address in the following patches. Reviewed-by: Oliver Upton Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211017124225.3018098-5-maz@kernel.org Signed-off-by: Daniel Lezcano --- arch/arm64/include/asm/arch_timer.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch/arm64/include/asm/arch_timer.h') diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 43f827b680d0..4f4aa13dd01e 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -96,8 +96,8 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u64 val) case ARCH_TIMER_REG_CTRL: write_sysreg(val, cntp_ctl_el0); break; - case ARCH_TIMER_REG_TVAL: - write_sysreg(val, cntp_tval_el0); + case ARCH_TIMER_REG_CVAL: + write_sysreg(val, cntp_cval_el0); break; default: BUILD_BUG(); @@ -107,8 +107,8 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u64 val) case ARCH_TIMER_REG_CTRL: write_sysreg(val, cntv_ctl_el0); break; - case ARCH_TIMER_REG_TVAL: - write_sysreg(val, cntv_tval_el0); + case ARCH_TIMER_REG_CVAL: + write_sysreg(val, cntv_cval_el0); break; default: BUILD_BUG(); @@ -121,7 +121,7 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u64 val) } static __always_inline -u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) +u64 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) { if (access == ARCH_TIMER_PHYS_ACCESS) { switch (reg) { -- cgit v1.2.3