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path: root/drivers/scsi/cxlflash/vlun.c
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2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-02scsi: cxlflash: Drop unused sense buffersKees Cook
This removes the unused sense buffer in read_cap16() and write_same16(). Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-18scsi: cxlflash: Isolate external module dependenciesUma Krishnan
Depending on the underlying transport, cxlflash has a dependency on either the CXL or OCXL drivers, which are enabled via their Kconfig option. Instead of having a module wide dependency on these config options, it is better to isolate the object modules that are dependent on the CXL and OCXL drivers and adjust the module dependencies accordingly. This commit isolates the object files that are dependent on CXL and/or OCXL. The cxl/ocxl fops used in the core driver are tucked under an ifdef to avoid compilation errors. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-10-31scsi: cxlflash: Use derived maximum write same lengthMatthew R. Ochs
The existing write same routine within the cxlflash driver uses a statically defined value for the maximum write same transfer length. While this is close to the value reflected by the original device that was supported by cxlflash, newer devices are capable of much larger lengths. Supporting what the device is capable of offers substantial performance improvement as the scrub routine within cxlflash operates on 'chunk size' units (256MB with a 4K sector size). Instead of a #define, use the write same maximum length that is stored in the block layer in units of 512 byte sectors. This value is initially determined from the block limits VPD page during device discovery and can also be manipulated from sysfs. As a general cleanup, designate the timeout used when executing the write same command as constant. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-08-25scsi: cxlflash: Fix vlun resize failure in the shrink pathUma Krishnan
The ioctl DK_CAPI_VLUN_RESIZE can fail if the allocated vlun size is reduced from almost maximum capacity and then increased again. The shrink_lxt() routine is currently using the SISL_ASTATUS_MASK to mask the higher 48 bits of the lxt entry. This is unnecessary and incorrect as it uses a mask designed for the asynchronous interrupt status register. When the 4 port support was added to cxlflash, the SISL_ASTATUS_MASK was updated to reflect the status bits for all 4 ports. This change indirectly affected the shrink_lxt() code path. To extract the base, simply shift the bits without masking. Fixes: 565180723294 ("scsi: cxlflash: SISlite updates to support 4 ports") Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-06-26scsi: cxlflash: Support WS16 unmapMatthew R. Ochs
The cxlflash driver supports performing a write-same16 to scrub virtual luns when they are released by a user. To date, AFUs for adapters that are supported by cxlflash do not have the capability to unmap as part of the WS operation. This can lead to fragmented flash devices which results in performance degradation. Future AFUs can optionally support unmap write-same commands and reflects this support via the context control register. This provides userspace applications with direct visibility such that they need not depend on a host API. Detect unmap support during cxlflash initialization by reading the context control register associated with the primary hardware queue. Update the existing write_same16() routine to set the unmap bit in the CDB when unmap is supported by the host. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-06-26scsi: cxlflash: Handle AFU sync failuresUma Krishnan
AFU sync operations are not currently evaluated for failure. This is acceptable for paths where there is not a dependency on the AFU being consistent with the host. Examples include link reset events and LUN cleanup operations. On paths where there is a dependency, such as a LUN open, a sync failure should be acted upon. In the event of AFU sync failures, either log or cleanup as appropriate for operations that are dependent on a successful sync completion. Update documentation to reflect behavior in the event of an AFU sync failure. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-04-13scsi: cxlflash: Hide FC internals behind common access routineMatthew R. Ochs
As staging to support FC-related updates to the SISlite specification, introduce helper routines to obtain references to FC resources that exist within the global map. This will allow changes to the underlying global map structure without impacting existing code paths. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-04-13scsi: cxlflash: Remove port configuration assumptionsMatthew R. Ochs
At present, the cxlflash driver only supports hardware with two FC ports. The code was initially designed with this assumption and is dependent on having two FC ports - adding more ports will break logic within the driver. To mitigate this issue, remove the existing port assumptions and transition the code to support more than two ports. As a side effect, clarify the interpretation of the DK_CXLFLASH_ALL_PORTS_ACTIVE flag. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-02-23scsi: merge __scsi_execute into scsi_executeChristoph Hellwig
All but one caller want the decoded sense header, so offer the existing __scsi_execute helper as the public scsi_execute API to simply the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-01-11scsi: cxlflash: Cleanup printsMatthew R. Ochs
The usage of prints within the cxlflash driver is inconsistent. This hinders debug and makes the driver source and log output appear sloppy. The following cleanups help unify the prints within cxlflash: - move all prints to dev-* where possible - transition all hex prints to lowercase - standardize variable prints in debug output - derive pointers in a consistent manner - change int to bool where appropriate - remove superfluous data from prints and print statements that do not make sense Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-08-23scsi: cxlflash: Transition to application close modelMatthew R. Ochs
Caching the adapter file descriptor and performing a close on behalf of an application is a poor design. This is due to the fact that once a file descriptor in installed, it is free to be altered without the knowledge of the cxlflash driver. This can lead to inconsistencies between the application and kernel. Furthermore, the nature of the former design is more exploitable and thus should be abandoned. To support applications performing a close on the adapter file that is associated with a context, a new flag is introduced to the user API to indicate to applications that they are responsible for the close following the cleanup (detach) of a context. The documentation is also updated to reflect this change in behavior. Inspired-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06cxlflash: Fix to avoid virtual LUN failover failureMatthew R. Ochs
Applications which use virtual LUN's that are backed by a physical LUN over both adapter ports may experience an I/O failure in the event of a link loss (e.g. cable pull). Virtual LUNs may be accessed through one or both ports of the adapter. This access is encoded in the translation entries that comprise the virtual LUN and used by the AFU for load-balancing I/O and handling failover scenarios. In a link loss scenario, even though the AFU is able to maintain connectivity to the LUN, it is up to the application to retry the failed I/O. When applications are unaware of the virtual LUN's underlying topology, they are unable to make a sound decision of when to retry an I/O and therefore are forced to make their reaction to a failed I/O absolute. The result is either a failure to retry I/O or increased latency for scenarios where a retry is pointless. To remedy this scenario, provide feedback back to the application on virtual LUN creation as to which ports the LUN may be accessed. LUN's spanning both ports are candidates for a retry in a presence of an I/O failure. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-10-30cxlflash: Fix to avoid potential deadlock on EEHMatthew R. Ochs
Ioctl threads that use scsi_execute() can run for an excessive amount of time due to the fact that they have lengthy timeouts and retry logic built in. Under normal operation this is not an issue. However, once EEH enters the picture, a long execution time coupled with the possibility that a timeout can trigger entry to the driver via registered reset callbacks becomes a liability. In particular, a deadlock can occur when an EEH event is encountered while in running in scsi_execute(). As part of the recovery, the EEH handler drains all currently running ioctls, waiting until they have completed before proceeding with a reset. As the scsi_execute()'s are situated on the ioctl path, the EEH handler will wait until they (and the remainder of the ioctl handler they're associated with) have completed. Normally this would not be much of an issue aside from the longer recovery period. Unfortunately, the scsi_execute() triggers a reset when it times out. The reset handler will see that the device is already being reset and wait until that reset completed. This creates a condition where the EEH handler becomes stuck, infinitely waiting for the ioctl thread to complete. To avoid this behavior, temporarily unmark the scsi_execute() threads as an ioctl thread by releasing the ioctl read semaphore. This allows the EEH handler to proceed with a recovery while the thread is still running. Once the scsi_execute() returns, the ioctl read semaphore is reacquired and the adapter state is rechecked in case it changed while inside of scsi_execute(). The state check will wait if the adapter is still being recovered or returns a failure if the recovery failed. In the event that the adapter reset failed, the failure is simply returned as the ioctl would be unable to continue. Reported-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Correct spelling, grammar, and alignment mistakesMatthew R. Ochs
There are several spelling and grammar mistakes throughout the driver. Additionally there are a handful of places where there are extra lines and unnecessary variables/statements. These are a nuisance and pollute the driver. Fix spelling and grammar issues. Update some comments for clarity and consistency. Remove extra lines and a few unneeded variables/statements. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix MMIO and endianness errorsMatthew R. Ochs
Sparse uncovered several errors with MMIO operations (accessing directly) and handling endianness. These can cause issues when running in different environments. Introduce __iomem and proper endianness tags/swaps where appropriate to make driver sparse clean. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix data corruption when vLUN used over multiple cardsMatthew R. Ochs
If the same virtual LUN is accessed over multiple cards, only accesses made over the first card will be valid. Accesses made over the second card will go to the wrong LUN causing data corruption. This is because the global LUN's mode word was being used to determine whether the LUN table for that card needs to be programmed. The mode word would be setup by the first card, causing the LUN table for the second card to not be programmed. By unconditionally initializing the LUN table (not depending on the mode word), the problem is avoided. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix read capacity timeoutManoj Kumar
The timeout value for read capacity is too small. Certain devices may take longer to respond and thus the command may prematurely timeout. Additionally the literal used for the timeout is stale. Update the timeout to 30 seconds (matches the value used in sd.c) and rework the timeout literal to a more appropriate description. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Replace magic numbers with literalsManoj Kumar
Magic numbers are not meaningful and can create confusion. As a remedy, replace them with descriptive literals. Replace 512 with literal MAX_SECTOR_UNIT. Replace 5 with literal CMD_RETRIES. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-08-26cxlflash: Virtual LUN supportMatthew R. Ochs
Add support for physical LUN segmentation (virtual LUNs) to device driver supporting the IBM CXL Flash adapter. This patch allows user space applications to virtually segment a physical LUN into N virtual LUNs, taking advantage of the translation features provided by this adapter. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>