On Thu, Mar 02, 2017 at 04:24:30PM -0700, Logan Gunthorpe wrote: > 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 Applied to pci/switchtec for v4.12, thanks!
