diff options
| author | Marc Zyngier <maz@kernel.org> | 2021-10-17 13:42:12 +0100 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2021-10-17 21:47:05 +0200 |
| commit | a38b71b0833eb2fabd2b1fa37d665c0a88b8b7e4 (patch) | |
| tree | 37d1e56f4814a8c8eb749be6bfd000201cb22a25 /arch/arm64/include/asm/arch_timer.h | |
| parent | 1e8d929231cf7b397101c5e6aaaa3d9bc9832f10 (diff) | |
| download | linux-a38b71b0833eb2fabd2b1fa37d665c0a88b8b7e4.tar.bz2 | |
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 <oupton@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-5-maz@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'arch/arm64/include/asm/arch_timer.h')
| -rw-r--r-- | arch/arm64/include/asm/arch_timer.h | 10 |
1 files changed, 5 insertions, 5 deletions
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) { |