From: Bjorn Helgaas <helgaas@kernel.org>
To: Vikram Sethi <vsethi@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
Chris Browy <cbrowy@avery-design.com>,
"linux-cxl@vger.kernel.org" <linux-cxl@vger.kernel.org>,
Ben Widawsky <ben.widawsky@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Alex Williamson <alex.williamson@redhat.com>,
Bjorn Helgaas <bjorn@helgaas.com>,
Shanker Donthineni <sdonthineni@nvidia.com>,
Amey Narkhede <ameynarkhede03@gmail.com>,
linux-pci@vger.kernel.org
Subject: Re: CXL Hot and Warm Reset Testing
Date: Fri, 13 Aug 2021 12:14:21 -0500 [thread overview]
Message-ID: <20210813171421.GA2593219@bjorn-Precision-5520> (raw)
In-Reply-To: <DM5PR12MB2534D383B0226498DD7F2005BDFA9@DM5PR12MB2534.namprd12.prod.outlook.com>
[+cc Amey (working on PCI resets), linux-pci]
On Fri, Aug 13, 2021 at 05:01:32PM +0000, Vikram Sethi wrote:
> Hi Dan,
>
> > -----Original Message-----
> > From: Dan Williams <dan.j.williams@intel.com>
> >
> > On Wed, Aug 11, 2021 at 9:42 AM Chris Browy <cbrowy@avery-design.com>
> > wrote:
> >
> > /sys/bus/pci/devices/$device/reset is a method to trigger PCI
> > device reset, but I do not expect that will ever gain CXL specific
> > knowledge.
> >
> CXL reset may need some thought, specially for devices that don't
> expose FLR but do expose CXL reset (while former does not affect
> CXL.cache/mem, the latter wipes out CXL.cache/mem state in the
> device and there is discoverability as to whether or not memory
> contents can be cleared as part of CXL reset). We may need a way of
> triggering CXL reset from userspace, and if the existing
> /sys/bus/pci/devices/$device/reset won't have knowledge of CXL
> reset, there still should be a prioritized order in the kernel in
> which CXL reset is attempted before more drastic resets like SBR.
> IIRC CXL reset can also impact all functions that use CXL.cache/mem,
> but not legacy PCIe functions on the device which do not use
> CXL.cache/mem (there is discoverability as to which functions are
> not impacted by CXL reset).
>
> Thanks,
> Vikram
next prev parent reply other threads:[~2021-08-13 17:14 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 19:47 [PATCH v1] cxl/pci: Fix debug message in cxl_probe_regs() Li Qiang (Johnny Li)
2021-08-11 15:38 ` Dan Williams
2021-08-11 16:35 ` CXL Hot and Warm Reset Testing Chris Browy
2021-08-12 1:08 ` Dan Williams
2021-08-13 17:01 ` Vikram Sethi
2021-08-13 17:14 ` Bjorn Helgaas [this message]
2021-08-13 21:27 ` Dan Williams
2021-08-17 3:03 ` Vikram Sethi
2021-08-14 11:16 ` Amey Narkhede
2021-08-14 19:47 ` Dan Williams
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