WSL2-Linux-Kernel/drivers/perf
Xu Yang 6e743b7261 perf/imx_ddr: speed up overflow frequency of cycle
[ Upstream commit e89ecd8368 ]

For i.MX8MP, we cannot ensure that cycle counter overflow occurs at least
4 times as often as other events. Due to byte counters will count for any
event configured, it will overflow more often. And if byte counters
overflow that related counters would stop since they share the
COUNTER_CNTL. We can speed up cycle counter overflow frequency by setting
counter parameter (CP) field of cycle counter. In this way, we can avoid
stop counting byte counters when interrupt didn't come and the byte
counters can be fetched or updated from each cycle counter overflow
interrupt.

Because we initialize CP filed to shorten counter0 overflow time, the cycle
counter will start couting from a fixed/base value each time. We need to
remove the base from the result too. Therefore, we could get precise result
from cycle counter.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20230811015438.1999307-1-xu.yang_2@nxp.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23 11:09:55 +02:00
..
hisilicon
Kconfig
Makefile
arm-cci.c
arm-ccn.c
arm-cmn.c perf/arm-cmn: Fix DTC reset 2023-07-23 13:46:46 +02:00
arm_dmc620_pmu.c perf/arm_dmc620: Fix hotplug callback leak in dmc620_pmu_init() 2022-12-31 13:13:58 +01:00
arm_dsu_pmu.c perf: arm_dsu: Fix hotplug callback leak in dsu_pmu_init() 2022-12-31 13:13:58 +01:00
arm_pmu.c
arm_pmu_acpi.c
arm_pmu_platform.c
arm_smmuv3_pmu.c perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09 2023-09-23 11:09:55 +02:00
arm_spe_pmu.c
fsl_imx8_ddr_perf.c perf/imx_ddr: speed up overflow frequency of cycle 2023-09-23 11:09:55 +02:00
qcom_l2_pmu.c
qcom_l3_pmu.c
thunderx2_pmu.c
xgene_pmu.c