Thread (12 messages) 12 messages, 4 authors, 2019-03-25

Re: [PATCH v6 4/4] perf/smmuv3_pmu: Enable HiSilicon Erratum 162001800 quirk

From: Hanjun Guo <guohanjun@huawei.com>
Date: 2019-02-14 07:30:12
Also in: linux-acpi, lkml

On 2019/2/4 20:13, Shameer Kolothum wrote:
HiSilicon erratum 162001800 describes the limitation of
SMMUv3 PMCG implementation on HiSilicon Hip08 platforms.

On these platforms, the PMCG event counter registers
(SMMU_PMCG_EVCNTRn) are read only and as a result it
is not possible to set the initial counter period value
on event monitor start.

To work around this, the current value of the counter
is read and used for delta calculations. OEM information
from ACPI header is used to identify the affected hardware
platforms.

Signed-off-by: Shameer Kolothum <redacted>
---
 drivers/acpi/arm64/iort.c     | 16 ++++++++++++++-
 drivers/perf/arm_smmuv3_pmu.c | 48 ++++++++++++++++++++++++++++++++++++-------
 include/linux/acpi_iort.h     |  1 +
 3 files changed, 57 insertions(+), 8 deletions(-)
For this patch,

Reviewed-by: Hanjun Guo <redacted>

Thanks
Hanjun


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