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Message-Id: <1488497074-14186-1-git-send-email-logang@deltatee.com>
Date: Thu, 2 Mar 2017 16:24:30 -0700
From: Logan Gunthorpe <logang@...tatee.com>
To: Keith Busch <keith.busch@...el.com>,
Myron Stowe <myron.stowe@...il.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Geert Uytterhoeven <geert+renesas@...der.be>,
Jonathan Corbet <corbet@....net>,
"David S. Miller" <davem@...emloft.net>,
Andrew Morton <akpm@...ux-foundation.org>,
Emil Velikov <emil.l.velikov@...il.com>,
Mauro Carvalho Chehab <mchehab@...nel.org>,
Guenter Roeck <linux@...ck-us.net>,
Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
Linus Walleij <linus.walleij@...aro.org>,
Ryusuke Konishi <konishi.ryusuke@....ntt.co.jp>,
Stefan Berger <stefanb@...ux.vnet.ibm.com>,
Wei Zhang <wzhang@...com>,
Jason Gunthorpe <jgunthorpe@...idianresearch.com>
Cc: Kurt Schwemmer <kurt.schwemmer@...rosemi.com>,
Stephen Bates <stephen.bates@...rosemi.com>,
linux-pci@...r.kernel.org, linux-doc@...r.kernel.org,
linux-nvme@...ts.infradead.org, linux-kernel@...r.kernel.org,
Logan Gunthorpe <logang@...tatee.com>
Subject: [PATCH v7 0/4] New Microsemi PCI Switch Management Driver
Because getting it right correctly the first time is appearantly hard
and I caught this mistake while reading the email I had just sent :(
I'm very sorry about the extra noise.
Logan
--
Changes since v6:
* I screwed up the device_unregister path and left a potential use
after free bug in. I'm not sure why I didn't see a failure because of
it but it all tested fine. This version is correct though.
Changes since v5:
* Reworked cleanup during unbind again. This time we follow the pattern
roughly suggested by Jason Gunthorpe: we use an alive flag
that's checked with a rw semaphore held by the cdev ops. Except
instead of using the rwsem we just use the already existing
mrpc_mutex. (Seeing the vast majority of locations that would use the
semaphore overlap with the existing mutex.)
* Added a small performance enhancement so the code reads less io memory
if the user is quick in submitting their read request.
Changes since v4:
* Turns out pushing the pci release code into the device release
function didn't work as I would have liked. If you try to unbind the
device with an instance open, then you hit a kernel bug at
drivers/pci/msi.c:371. (This didn't occur in v3.)
To solve this, we've moved the pci release code back into the
unregister function and reintroduced an alive flag. This time,
however, the alive flag is protected by mrpc_mutex and we're very
careful about what happens to devices still in use (they should
all be released through the timeout path and an ENODEV error
returned to userspace; while new commands are blocked with the
same error).
Changes since v3:
* Removed stdev_is_alive and moved pci deinit functions
into the device release function which only occurs after all
cdev instances are closed. (per Bjorn)
* Reduced locking in read/write functions (per Bjorn)
* Use pci_alloc_irq_vectors to vastly improve ISR initialization (Bjorn)
* A few other minor nits and cleanup as noticed by Bjorn
Changes since v2:
* Collected reviewed and tested tags
* Very minor fix to the error path in the create function
Changes since v1:
* Rebased onto 4.10-rc6 (cleanly)
* Split the patch into a few more easily digestible patches (as
suggested by Greg Kroah-Hartman)
* Folded switchtec.c into switchtec.h (per Greg)
* Fixed a bunch of 32bit build warnings caught by the kbuild test robot
* Fixed some issues in the documentation so it has a proper
reStructredText format (as noted by Jonathan Corbet)
* Fixed padding and sizes in the IOCTL structures as noticed by Emil
Velikov and used pahole to verify their consistency across 32 and 64
bit builds
* Reworked one of the IOCTL interfaces to be more future proof (per
Emil).
Changes since RFC:
* Fixed incorrect use of the drive model as pointed out by Greg
Kroah-Hartman
* Used devm functions as suggested by Keith Busch
* Added a handful of sysfs attributes to the switchtec class
* Added a handful of IOCTLs to the switchtec device
* A number of miscellaneous bug fixes
--
Hi,
This is a continuation of the RFC we posted lasted month [1] which
proposes a management driver for Microsemi's Switchtec line of PCI
switches. This hardware is still looking to be used in the Open
Compute Platform
To make this entirely clear: the Switchtec products are compliant
with the PCI specifications and are supported today with the standard
in-kernel driver. However, these devices also expose a management endpoint
on a separate PCI function address which can be used to perform some
advanced operations. This is a driver for that function. See the patch
for more information.
Since the RFC, we've made the changes requested by Greg Kroah-Hartman
and Keith Busch, and we've also fleshed out a number of features. We've
added a couple of IOCTLs and sysfs attributes which are documented in
the patch. Significant work has also been done on the userspace tool
which is available under a GPL license at [2]. We've also had testing
done by some of the interested parties.
We hope to see this work included in either 4.11 or 4.12 assuming a
smooth review process.
The patch is based off of the v4.10-rc6 release.
Thanks for your review,
Logan
[1] https://www.spinics.net/lists/linux-pci/msg56897.html
[2] https://github.com/sbates130272/switchtec-user
Logan Gunthorpe (4):
MicroSemi Switchtec management interface driver
switchtec: Add user interface documentation
switchtec: Add sysfs attributes to the Switchtec driver
switchtec: Add IOCTLs to the Switchtec driver
Documentation/ABI/testing/sysfs-class-switchtec | 96 ++
Documentation/ioctl/ioctl-number.txt | 1 +
Documentation/switchtec.txt | 80 ++
MAINTAINERS | 11 +
drivers/pci/Kconfig | 1 +
drivers/pci/Makefile | 1 +
drivers/pci/switch/Kconfig | 13 +
drivers/pci/switch/Makefile | 1 +
drivers/pci/switch/switchtec.c | 1600 +++++++++++++++++++++++
include/uapi/linux/switchtec_ioctl.h | 132 ++
10 files changed, 1936 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-switchtec
create mode 100644 Documentation/switchtec.txt
create mode 100644 drivers/pci/switch/Kconfig
create mode 100644 drivers/pci/switch/Makefile
create mode 100644 drivers/pci/switch/switchtec.c
create mode 100644 include/uapi/linux/switchtec_ioctl.h
--
2.1.4
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