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
