Re: [PATCH v11 0/8] Add support for HiSilicon PCIe Tune and Trace device

[Yicong Yang]

On 2022/7/25 22:32, Mathieu Poirier wrote:
> On Fri, 22 Jul 2022 at 08:53, Yicong Yang <yangyccccc@xxxxxxxxx> wrote:
>>
>> 在 7/21/2022 11:43 PM, Mathieu Poirier 写道:
>>> On Thu, 21 Jul 2022 at 07:03, <yangyicong@xxxxxxxxxx> wrote:
>>>> From: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
>>>>
>>>> HiSilicon PCIe tune and trace device (PTT) is a PCIe Root Complex
>>>> integrated Endpoint (RCiEP) device, providing the capability
>>>> to dynamically monitor and tune the PCIe traffic (tune),
>>>> and trace the TLP headers (trace).
>>>>
>>>> PTT tune is designed for monitoring and adjusting PCIe link parameters.
>>>> We provide several parameters of the PCIe link. Through the driver,
>>>> user can adjust the value of certain parameter to affect the PCIe link
>>>> for the purpose of enhancing the performance in certian situation.
>>>>
>>>> PTT trace is designed for dumping the TLP headers to the memory, which
>>>> can be used to analyze the transactions and usage condition of the PCIe
>>>> Link. Users can choose filters to trace headers, by either requester
>>>> ID, or those downstream of a set of Root Ports on the same core of the
>>>> PTT device. It's also supported to trace the headers of certain type and
>>>> of certain direction.
>>>>
>>>> The driver registers a PMU device for each PTT device. The trace can
>>>> be used through `perf record` and the traced headers can be decoded
>>>> by `perf report`. The perf command support for the device is also
>>>> added in this patchset. The tune can be used through the sysfs
>>>> attributes of related PMU device. See the documentation for the
>>>> detailed usage.
>>>>
>>>> Change since v10:
>>>> - Use title case in the documentation
>>>> - Add RB from Bagas, thanks.
>>>> Link: https://lore.kernel.org/lkml/20220714092710.53486-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v9:
>>>> - Add sysfs ABI description documentation
>>>> - Remove the controversial available_{root_port, requester}_filters sysfs file
>>>> - Shorten 2 tune sysfs attributes name and add some comments
>>>> - Move hisi_ptt_process_auxtrace_info() to Patch 6.
>>>> - Add RB from Leo and Ack-by from Mathieu, thanks!
>>> You can add my Ack-by to patch 03 as well.  See below for another comment.
>>
>> Thanks!
>>
>>>> Link: https://lore.kernel.org/lkml/20220606115555.41103-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v8:
>>>> - Cleanups and one minor fix from Jonathan and John, thanks
>>>> Link: https://lore.kernel.org/lkml/20220516125223.32012-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v7:
>>>> - Configure the DMA in probe rather than in runtime. Also use devres to manage
>>>>   PMU device as we have no order problem now
>>>> - Refactor the config validation function per John and Leo
>>>> - Use a spinlock hisi_ptt::pmu_lock instead of mutex to serialize the perf process
>>>>   in pmu::start as it's in atomic context
>>>> - Only commit the traced data when stop, per Leo and James
>>>> - Drop the filter dynamically updating patch from this series to simply the review
>>>>   of the driver. That patch will be send separately.
>>>> - add a cpumask sysfs attribute and handle the cpu hotplug events, follow the
>>>>   uncore PMU convention
>>>> - Other cleanups and fixes, both in driver and perf tool
>>>> Link: https://lore.kernel.org/lkml/20220407125841.3678-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v6:
>>>> - Fix W=1 errors reported by lkp test, thanks
>>>>
>>>> Change since v5:
>>>> - Squash the PMU patch into PATCH 2 suggested by John
>>>> - refine the commit message of PATCH 1 and some comments
>>>> Link: https://lore.kernel.org/lkml/20220308084930.5142-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v4:
>>>> Address the comments from Jonathan, John and Ma Ca, thanks.
>>>> - Use devm* also for allocating the DMA buffers
>>>> - Remove the IRQ handler stub in Patch 2
>>>> - Make functions waiting for hardware state return boolean
>>>> - Manual remove the PMU device as it should be removed first
>>>> - Modifier the orders in probe and removal to make them matched well
>>>> - Make available {directions,type,format} array const and non-global
>>>> - Using the right filter list in filters show and well protect the
>>>>   list with mutex
>>>> - Record the trace status with a boolean @started rather than enum
>>>> - Optimize the process of finding the PTT devices of the perf-tool
>>>> Link: https://lore.kernel.org/linux-pci/20220221084307.33712-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v3:
>>>> Address the comments from Jonathan and John, thanks.
>>>> - drop members in the common struct which can be get on the fly
>>>> - reduce buffer struct and organize the buffers with array instead of list
>>>> - reduce the DMA reset wait time to avoid long time busy loop
>>>> - split the available_filters sysfs attribute into two files, for root port
>>>>   and requester respectively. Update the documentation accordingly
>>>> - make IOMMU mapping check earlier in probe to avoid race condition. Also
>>>>   make IOMMU quirk patch prior to driver in the series
>>>> - Cleanups and typos fixes from John and Jonathan
>>>> Link: https://lore.kernel.org/linux-pci/20220124131118.17887-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v2:
>>>> - address the comments from Mathieu, thanks.
>>>>   - rename the directory to ptt to match the function of the device
>>>>   - spinoff the declarations to a separate header
>>>>   - split the trace function to several patches
>>>>   - some other comments.
>>>> - make default smmu domain type of PTT device to identity
>>>>   Drop the RMR as it's not recommended and use an iommu_def_domain_type
>>>>   quirk to passthrough the device DMA as suggested by Robin.
>>>> Link: https://lore.kernel.org/linux-pci/20211116090625.53702-1-yangyicong@xxxxxxxxxxxxx/
>>>>
>>>> Change since v1:
>>>> - switch the user interface of trace to perf from debugfs
>>>> - switch the user interface of tune to sysfs from debugfs
>>>> - add perf tool support to start trace and decode the trace data
>>>> - address the comments of documentation from Bjorn
>>>> - add RMR[1] support of the device as trace works in RMR mode or
>>>>   direct DMA mode. RMR support is achieved by common APIs rather
>>>>   than the APIs implemented in [1].
>>>> Link: https://lore.kernel.org/lkml/1618654631-42454-1-git-send-email-yangyicong@xxxxxxxxxxxxx/
>>>> [1] https://lore.kernel.org/linux-acpi/20210805080724.480-1-shameerali.kolothum.thodi@xxxxxxxxxx/
>>>>
>>>> Qi Liu (3):
>>>>   perf tool: arm: Refactor event list iteration in
>>>>     auxtrace_record__init()
>>>>   perf tool: Add support for HiSilicon PCIe Tune and Trace device driver
>>>>   perf tool: Add support for parsing HiSilicon PCIe Trace packet
>>>>
>>>> Yicong Yang (5):
>>>>   iommu/arm-smmu-v3: Make default domain type of HiSilicon PTT device to
>>>>     identity
>>>>   hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe
>>>>     Tune and Trace device
>>>>   hwtracing: hisi_ptt: Add tune function support for HiSilicon PCIe Tune
>>>>     and Trace device
>>>>   docs: trace: Add HiSilicon PTT device driver documentation
>>>>   MAINTAINERS: Add maintainer for HiSilicon PTT driver
>>>>
>>>>  .../ABI/testing/sysfs-devices-hisi_ptt        |   61 +
>>>>  Documentation/trace/hisi-ptt.rst              |  298 +++++
>>>>  Documentation/trace/index.rst                 |    1 +
>>>>  MAINTAINERS                                   |    8 +
>>>>  drivers/Makefile                              |    1 +
>>>>  drivers/hwtracing/Kconfig                     |    2 +
>>>>  drivers/hwtracing/ptt/Kconfig                 |   12 +
>>>>  drivers/hwtracing/ptt/Makefile                |    2 +
>>>>  drivers/hwtracing/ptt/hisi_ptt.c              | 1032 +++++++++++++++++
>>>>  drivers/hwtracing/ptt/hisi_ptt.h              |  200 ++++
>>>>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |   21 +
>>> Everything above needs to go in one patchset and everything below in
>>> another one.  The first patchset will need to be merged before the
>>> second one.  Someone already commented on that.
>>
>> ok. I put them together to provide an overall view of this and thought maintainers can take
>> them separately. Will spilt the driver part and perf tool patches.
>>
>> I still don't know who will finally take the driver part. It should be Alexander from maintainer
>> list but I got no response yet for a long time. Any hint for this?
> 
> It will either be Peter, Greg or myself.  We'll see when we get there.

Thanks a lot for the information! Since it's going to be the merge window soon, I'll continue this on
the next cycle.

Regards.