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path: root/drivers/scsi/cxlflash/main.c
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* scsi: cxlflash: Remove unnecessary DMA mappingMatthew R. Ochs2017-04-131-13/+2
| | | | | | | | | | Devices supported by the cxlflash driver are fully coherent and do not require a bus address mapping. Avoid unnecessary path length by using the virtual address and length already present in the scatter-gather entry. 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>
* scsi: cxlflash: Fence EEH during probeMatthew R. Ochs2017-04-131-4/+21
| | | | | | | | | | | An EEH during probe can lead to a crash as the recovery thread races with the probe thread. To avoid this issue, introduce new states to fence out EEH recovery until probe has completed. Also ensure the reset wait queue is flushed during device removal to avoid orphaned threads. 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>
* scsi: cxlflash: Support up to 4 portsMatthew R. Ochs2017-04-131-1/+77
| | | | | | | | Update the driver to allow for future cards with 4 ports. 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>
* scsi: cxlflash: SISlite updates to support 4 portsMatthew R. Ochs2017-04-131-19/+58
| | | | | | | | | | | Update the SISlite header to support 4 ports as outlined in the SISlite specification. Address fallout from structure renames and refreshed organization throughout the driver. Determine the number of ports supported by a card from the global port selection mask register reset value. 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>
* scsi: cxlflash: Hide FC internals behind common access routineMatthew R. Ochs2017-04-131-33/+39
| | | | | | | | | | | 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>
* scsi: cxlflash: Remove port configuration assumptionsMatthew R. Ochs2017-04-131-7/+6
| | | | | | | | | | | | | | 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>
* scsi: cxlflash: Support dynamic number of FC portsMatthew R. Ochs2017-04-131-27/+44
| | | | | | | | | | Transition from a static number of FC ports to a value that is derived during probe. For now, a static value is used but this will later be based on the type of card being configured. 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>
* scsi: cxlflash: Update sysfs helper routines to pass config structureMatthew R. Ochs2017-04-131-12/+12
| | | | | | | | | As staging for future function, pass the config pointer instead of the AFU pointer for port-related sysfs helper routines. 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>
* scsi: cxlflash: Implement IRQ polling for RRQ processingMatthew R. Ochs2017-04-131-4/+119
| | | | | | | | | | | | | | Currently, RRQ processing takes place on hardware interrupt context. This can be a heavy burden in some environments due to the overhead encountered while completing RRQ entries. In an effort to improve system performance, use the IRQ polling API to schedule this processing on softirq context. This function will be disabled by default until starting values can be established for the hardware supported by this driver. 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>
* scsi: cxlflash: Serialize RRQ access and support offlevel processingMatthew R. Ochs2017-04-131-7/+35
| | | | | | | | | | | | | | | As further staging to support processing the HRRQ by other means, access to the HRRQ needs to be serialized by a disabled lock. This will allow safe access in other non-hardware interrupt contexts. In an effort to minimize the period where interrupts are disabled, support is added to queue up commands harvested from the RRQ such that they can be processed with hardware interrupts enabled. While this doesn't offer any improvement with processing on a hardware interrupt it will help when IRQ polling is supported and the command completions can execute on softirq context. 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>
* scsi: cxlflash: Separate RRQ processing from the RRQ interrupt handlerMatthew R. Ochs2017-04-131-6/+21
| | | | | | | | | | | In order to support processing the HRRQ by other means (e.g. polling), the processing portion of the current RRQ interrupt handler needs to be broken out into a separate routine. This will allow RRQ processing from places other than the RRQ hardware interrupt handler. 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>
* scsi: cxlflash: Enable PCI device ID for future IBM CXL Flash AFUMatthew R. Ochs2017-02-221-0/+4
| | | | | | | | | Add support for a future IBM Coherent Accelerator (CXL) flash AFU with an ID of 0x0624. 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>
* scsi: cxlflash: Cancel scheduled workers before stopping AFUUma Krishnan2017-01-111-28/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When processing an AFU asynchronous interrupt, if the action results in an operation that requires off level processing (a link reset for example), the worker thread is scheduled. In the meantime a reset event (i.e.: EEH) could unmap the AFU to recover. This results in an Oops when the worker thread tries to access the AFU mapping. [c000000f17e03b90] d000000007cd5978 cxlflash_worker_thread+0x268/0x550 [c000000f17e03c40] c00000000011883c process_one_work+0x1dc/0x680 [c000000f17e03ce0] c000000000118e80 worker_thread+0x1a0/0x520 [c000000f17e03d80] c000000000126174 kthread+0xf4/0x100 [c000000f17e03e30] c00000000000a47c ret_from_kernel_thread+0x5c/0xe0 In an effort to avoid this, a mapcount was introduced in commit b45cdbaf9f7f ("cxlflash: Resolve oops in wait_port_offline") but due to the race condition described above, this solution is incomplete. In order to fully resolve this problem and to simplify things, this commit removes the mapcount solution. Instead, the scheduled worker thread is cancelled after interrupts have been disabled and prior to the mapping being freed. Fixes: b45cdbaf9f7f ("cxlflash: Resolve oops in wait_port_offline") 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>
* scsi: cxlflash: Cleanup printsMatthew R. Ochs2017-01-111-167/+152
| | | | | | | | | | | | | | | | | | | 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>
* scsi: cxlflash: Support SQ Command ModeMatthew R. Ochs2017-01-111-5/+93
| | | | | | | | | | | | | | | The SISLite specification outlines a new queuing model to improve over the MMIO-based IOARRIN model that exists today. This new model uses a submission queue that exists in host memory and is shared with the device. Each entry in the queue is an IOARCB that describes a transfer request. When requests are submitted, IOARCBs ('current' position tracked in host software) are populated and the submission queue tail pointer is then updated via MMIO to make the device aware of the requests. 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>
* scsi: cxlflash: Refactor context reset to share reset logicMatthew R. Ochs2017-01-111-4/+16
| | | | | | | | | | | | As staging for supporting hardware with different context reset registers but a similar reset procedure, refactor the existing context reset routine to move the reset logic to a common routine. This will allow hardware with a different reset register to leverage existing code. 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>
* scsi: cxlflash: Migrate scsi command pointer to AFU commandMatthew R. Ochs2016-11-301-5/+5
| | | | | | | | | | | | Currently, when sending a SCSI command, the pointer is stored in a reserved field of the AFU command descriptor for retrieval once the SCSI command has completed. In order to support new descriptor formats that make use of the reserved field, the pointer is migrated to outside the descriptor where it can still be found during completion processing. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Migrate IOARRIN specific routines to function pointersMatthew R. Ochs2016-11-301-10/+11
| | | | | | | | | | | As staging for supporting hardware with a different queuing mechanism, move the send_cmd() and context_reset() routines to function pointers that are configured when the AFU is initialized. In addition, rename the existing routines to better reflect the queue model they support. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Cleanup queuecommand()Matthew R. Ochs2016-11-301-30/+20
| | | | | | | | | | | | | | | | The queuecommand routine is disorganized where it populates the private command and also contains some logic/statements that are not needed given that cxlflash devices do not (and likely never will) support scatter-gather. Restructure the code to remove the unnecessary logic and create an organized flow: handle state -> DMA map -> populate command -> send command Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Cleanup send_tmf()Matthew R. Ochs2016-11-301-15/+7
| | | | | | | | | | | | The send_tmf() routine includes some copy/paste cruft that can be removed as well as the setting of an AFU command-specific while holding the tmf_slock. While not a bug, it is out of place and should be shifted down alongside the other command initialization statements for clarity. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Remove AFU command lockMatthew R. Ochs2016-11-301-31/+15
| | | | | | | | | | | | | | | | | | The original design of the cxlflash driver required AFU commands to convey state information across multiple threads. The IOASA "host use" byte was used to track if a command was done, errored, or timed out. A per-command spin lock was used to serialize access to this byte. As this is no longer required with the introduction of completions and various refactoring over time, the spin lock, state tracking, and associated code can be removed. To support the simplification, the wait_resp() routine is refactored to return a success or failure. Additionally, as the simplification to the AFU internal command routine, explicit assignments of AFU command fields to zero are removed as the memory is zeroed upon allocation. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Wait for active AFU commands to timeout upon tear downMatthew R. Ochs2016-11-301-1/+5
| | | | | | | | | | | | | | | With the removal of the static private command pool, the ability to 'complete' outstanding commands was lost. While not an issue for the commands originating outside the driver, internal AFU commands are synchronous and therefore have a timeout associated with them. To avoid a stale memory access, the tear down sequence needs to ensure that there are not any active commands before proceeding. As these internal AFU commands are rare events, the simplest way to accomplish this is detecting the activity and waiting for it to timeout. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Remove private command poolMatthew R. Ochs2016-11-301-68/+0
| | | | | | | | | Clean up and remove the remaining private command pool infrastructure that is no longer required. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Use cmd_size for private commandsMatthew R. Ochs2016-11-301-54/+11
| | | | | | | | | | | | | Instead of using a private pool of AFU commands, use cmd_size to prime the private pool of SCSI commands such that they are allocated with a size large enough to contain an aligned AFU command. Use scsi_cmd_priv() to derive the aligned/zeroed private command on queuecommand and TMF paths. Remove cmd_checkout() as it is no longer required. The remaining AFU private command infrastructure will be removed in a cleanup commit. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Allocate memory instead of using command pool for AFU syncMatthew R. Ochs2016-11-301-13/+12
| | | | | | | | | | | | As staging for the removal of the AFU command pool, remove the reliance upon the pool for the internal AFU sync command. Instead of obtaining an AFU command from the pool, dynamically allocate memory with the appropriate alignment requirements. Since the AFU sync service is only executed from the process environment, blocking is acceptable. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Remove unused buffer from AFU commandMatthew R. Ochs2016-11-301-26/+2
| | | | | | | | | | | | The cxlflash driver originally required a per-command 4K buffer that hosted data passed to the AFU. When the routines that initiate AFU and internal SCSI commands were refactored to use scsi_execute(), the need for this buffer became obsolete. As it is no longer necessary, the buffer is removed. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Avoid command room violationUma Krishnan2016-11-301-48/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During test, a command room violation interrupt is occasionally seen for the master context when the CXL flash devices are stressed. After studying the code, there could be gaps in the way command room value is being cached in cxlflash. When the cached command room is zero the thread attempting to send becomes burdened with updating the cached value with the actual value from the AFU. Today, this is handled with an atomic set operation of the raw value read. Following the atomic update, the thread proceeds to send. This behavior is incorrect on two counts: - The update fails to take into account the current thread and its consumption of one of the hardware commands. - The update does not take into account other threads also atomically updating. Per design, a worker thread updates the cached value when a send thread times out. By not protecting the update with a lock, the cached value can be incorrectly clobbered. To correct these issues, the update of the cached command room has been simplified and also protected using a spin lock which is held until the MMIO is complete. This ensures the command room is properly consumed by the same thread. Update of cached value also takes into account the current thread consuming a hardware command. 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>
* scsi: cxlflash: Improve context_reset() logicUma Krishnan2016-11-301-18/+5
| | | | | | | | | | | | | | | | | Currently, the context reset routine waits for command room to be available before sending the reset request. Per review of the SISLite specification and clarifications from the CXL Flash AFU designers, this wait is unnecessary. The reset request can be sent anytime regardless of command room, so long as only a single reset request is active at any one point in time. This commit simplifies the reset routine by removing the wait for command room. Additionally it adds a debug trace to help pinpoint hardware errors when a context reset does not complete. 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>
* scsi: cxlflash: Set sg_tablesize to 1 instead of SG_NONEUma Krishnan2016-11-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following Oops is encountered when blk_mq is enabled with the cxlflash driver: [ 2960.817172] Oops: Kernel access of bad area, sig: 11 [#5] [ 2960.817309] NIP __blk_mq_run_hw_queue+0x278/0x4c0 [ 2960.817313] LR __blk_mq_run_hw_queue+0x2bc/0x4c0 [ 2960.817314] Call Trace: [ 2960.817320] __blk_mq_run_hw_queue+0x2bc/0x4c0 (unreliable) [ 2960.817324] blk_mq_run_hw_queue+0xd8/0x100 [ 2960.817329] blk_mq_insert_requests+0x14c/0x1f0 [ 2960.817333] blk_mq_flush_plug_list+0x150/0x190 [ 2960.817338] blk_flush_plug_list+0x11c/0x2b0 [ 2960.817344] blk_finish_plug+0x58/0x80 [ 2960.817348] __do_page_cache_readahead+0x1c0/0x2e0 [ 2960.817352] force_page_cache_readahead+0x68/0xd0 [ 2960.817356] generic_file_read_iter+0x43c/0x6a0 [ 2960.817359] blkdev_read_iter+0x68/0xa0 [ 2960.817361] __vfs_read+0x11c/0x180 [ 2960.817364] vfs_read+0xa4/0x1c0 [ 2960.817366] SyS_read+0x6c/0x110 [ 2960.817369] system_call+0x38/0xb4 The SCSI blk_mq stack assumes that sg_tablesize is always a non-zero value with scsi_mq_setup_tags() allocating tags using sg_tablesize. The cxlflash driver currently uses SG_NONE (0) for the sg_tablesize as the devices it supports are not capable of scatter gather. This mismatch of values results in the Oops above. To resolve this issue, sg_tablesize for cxlflash can simply be set to 1, a value which satisfies the constraints in cxlflash and the lack of support of SG_NONE in SCSI blk_mq. 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>
* scsi: cxlflash: Refactor WWPN setupMatthew R. Ochs2016-09-141-31/+9
| | | | | | | | | | | Commit 964497b3bf3f ("cxlflash: Remove dual port online dependency") logically removed the ability for the WWPN setup routine afu_set_wwpn() to return a non-success value. This routine can safely be made a void to simplify the code as there is no longer a need to report a failure. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Improve EEH recovery timeMatthew R. Ochs2016-09-141-0/+4
| | | | | | | | | | | | | | | | When an EEH occurs during device initialization, the port timeout logic can cause excessive delays as MMIO reads will fail. Depending on where they are experienced, these delays can lead to a prolonged reset, causing an unnecessary triggering of other timeout logic in the SCSI stack or user applications. To expedite recovery, the port timeout logic is updated to decay the timeout at a much faster rate when in the presence of a likely EEH frozen event. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Fix to avoid EEH and host reset collisionsMatthew R. Ochs2016-09-141-1/+14
| | | | | | | | | | | | | | | | | | | | | The EEH reset handler is ignorant to the current state of the driver when processing a frozen event and initiating a device reset. This can be an issue if an EEH event occurs while a user or stack initiated reset is executing. More specifically, if an EEH occurs while the SCSI host reset handler is active, the reset initiated by the EEH thread will likely collide with the host reset thread. This can leave the device in an inconsistent state, or worse, cause a system crash. As a remedy, the EEH handler is updated to evaluate the device state and take appropriate action (proceed, wait, or disconnect host). The host reset handler is also updated to handle situations where an EEH occurred during a host reset. In such situations, the host reset handler will delay reporting back a success to give the EEH reset an opportunity to complete. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* scsi: cxlflash: Remove the device cleanly in the system shutdown pathUma Krishnan2016-09-091-12/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards") was recently introduced to notify the AFU when a system is going down. Due to the position of the cxlflash driver in the device stack, cxlflash devices are _always_ removed during a reboot/shutdown. This can lead to a crash if the cxlflash shutdown hook is invoked _after_ the shutdown hook for the owning virtual PHB. Furthermore, the current implementation of shutdown/remove hooks for cxlflash are not tolerant to being invoked when the device is not enabled. This can also lead to a crash in situations where the remove hook is invoked after the device has been removed via the vPHBs shutdown hook. An example of this scenario would be an EEH reset failure while a reboot/shutdown is in progress. To solve both problems, the shutdown hook for cxlflash is updated to simply remove the device. This path already includes the AFU notification and thus this solution will continue to perform the original intent. At the same time, the remove hook is updated to protect against being called when the device is not enabled. Fixes: 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards") 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>
* scsi: cxlflash: Scan host only after the port is ready for I/OUma Krishnan2016-09-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | When a port link is established, the AFU sends a 'link up' interrupt. After the link is up, corresponding initialization steps are performed on the card. Following that, when the card is ready for I/O, the AFU sends 'login succeeded' interrupt. Today, cxlflash invokes scsi_scan_host() upon receipt of both interrupts. SCSI commands sent to the port prior to the 'login succeeded' interrupt will fail with 'port not available' error. This is not desirable. Moreover, when async_scan is active for the host, subsequent scan calls are terminated with error. Due to this, the scsi_scan_host() call performed after 'login succeeded' interrupt could portentially return error and the devices may not be scanned properly. To avoid this problem, scsi_scan_host() should be called only after the 'login succeeded' interrupt. 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>
* cxlflash: Verify problem state area is mapped before notifying shutdownUma Krishnan2016-07-271-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | If an EEH or some other hard error occurs while the adapter instance was being initialized, on the subsequent shutdown of the device, the system could crash with: [c000000f1da03b60] c0000000005eccfc pci_device_shutdown+0x6c/0x100 [c000000f1da03ba0] c0000000006d67d4 device_shutdown+0x1b4/0x2c0 [c000000f1da03c40] c0000000000ea30c kernel_restart_prepare+0x5c/0x80 [c000000f1da03c70] c0000000000ea48c kernel_restart+0x2c/0xc0 [c000000f1da03ce0] c0000000000ea970 SyS_reboot+0x1c0/0x2d0 [c000000f1da03e30] c000000000009204 system_call+0x38/0xb4 This crash is due to the AFU not being mapped when the shutdown notification routine is called and is a regression that was inserted recently with Commit 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards"). As a fix, shutdown notification should only occur when the AFU is mapped. Fixes: 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards") Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* cxlflash: Shutdown notify support for CXL Flash cardsUma Krishnan2016-07-121-1/+66
| | | | | | | | | | | | | | | Some CXL Flash cards need notification of device shutdown in order to flush pending I/Os. A PCI notification hook for shutdown has been added where the driver notifies the card and returns. When the device is removed in the PCI remove path, notification code will wait for shutdown processing to complete. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* cxlflash: Add device dependent flagsUma Krishnan2016-07-121-2/+4
| | | | | | | | | | | | | | | | | | | Device dependent flags are needed to support functions that are specific to a particular device. One such case is - some CXL Flash cards need to be notified of device shutdown. For other CXL devices, this feature does not prove to be useful yet. Such distinct features need to be identified in the driver to bypass or invoke specific functionality. In this patch, a member 'flags' has been added to device dependent values. These flags will be used and expanded in the future to support various device specific functions. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* cxlflash: Fix to drain operations from previous resetManoj N. Kumar2016-07-121-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running 'sg_reset -H' in a loop with a user-space application active, hit the following exception: cpu 0x2: Vector: 300 (Data Access) pc: : afu_attach+0x50/0x240 [cxlflash] lr: : cxlflash_afu_recover+0x3dc/0x7d0 [cxlflash] pid = 20365, comm = run_block_fvt Linux version 4.5.0-491-26f710d+ cxlflash_afu_recover+0x3dc/0x7d0 [cxlflash] cxlflash_ioctl+0x5a8/0x6f0 [cxlflash] scsi_ioctl+0x3b0/0x4c0 sd_ioctl+0x110/0x190 blkdev_ioctl+0x28c/0xc20 block_ioctl+0xa4/0xd0 do_vfs_ioctl+0xd8/0x8c0 SyS_ioctl+0xd4/0xf0 system_call+0x38/0xb4 The problem here is that the problem space area is unmapped while the application issues the DK_CXLFLASH_RECOVER_AFU ioctl. This is the order I observe: proc1 proc2 1) sg_reset 2) ioctl(DK_CXLFLASH_RECOVER_AFU) 3) sg_reset again causing a PSA unmap 4) continues RECOVER_AFU processing The resolution to this problem is to have the reset handler drain all outstanding user space initiated ioctls before proceeding. It is safe to drain after the state has been changed to STATE_RESET. Also since drain_ioctls() was static, it had to be moved up a bit to be before cxlflash_eh_host_reset_handler(). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* Merge branch 'fixes-base' into fixesJames Bottomley2016-04-051-16/+2
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| * Merge tag 'powerpc-4.6-1' of ↵Linus Torvalds2016-03-191-16/+2
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "This was delayed a day or two by some build-breakage on old toolchains which we've now fixed. There's two PCI commits both acked by Bjorn. There's one commit to mm/hugepage.c which is (co)authored by Kirill. Highlights: - Restructure Linux PTE on Book3S/64 to Radix format from Paul Mackerras - Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh Kumar K.V - Add POWER9 cputable entry from Michael Neuling - FPU/Altivec/VSX save/restore optimisations from Cyril Bur - Add support for new ftrace ABI on ppc64le from Torsten Duwe Various cleanups & minor fixes from: - Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy, Cyril Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell Currey, Sukadev Bhattiprolu, Suraj Jitindar Singh. General: - atomics: Allow architectures to define their own __atomic_op_* helpers from Boqun Feng - Implement atomic{, 64}_*_return_* variants and acquire/release/ relaxed variants for (cmp)xchg from Boqun Feng - Add powernv_defconfig from Jeremy Kerr - Fix BUG_ON() reporting in real mode from Balbir Singh - Add xmon command to dump OPAL msglog from Andrew Donnellan - Add xmon command to dump process/task similar to ps(1) from Douglas Miller - Clean up memory hotplug failure paths from David Gibson pci/eeh: - Redesign SR-IOV on PowerNV to give absolute isolation between VFs from Wei Yang. - EEH Support for SRIOV VFs from Wei Yang and Gavin Shan. - PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang - PCI: Add pcibios_bus_add_device() weak function from Wei Yang - MAINTAINERS: Update EEH details and maintainership from Russell Currey cxl: - Support added to the CXL driver for running on both bare-metal and hypervisor systems, from Christophe Lombard and Frederic Barrat. - Ignore probes for virtual afu pci devices from Vaibhav Jain perf: - Export Power8 generic and cache events to sysfs from Sukadev Bhattiprolu - hv-24x7: Fix usage with chip events, display change in counter values, display domain indices in sysfs, eliminate domain suffix in event names, from Sukadev Bhattiprolu Freescale: - Updates from Scott: "Highlights include 8xx optimizations, 32-bit checksum optimizations, 86xx consolidation, e5500/e6500 cpu hotplug, more fman and other dt bits, and minor fixes/cleanup" * tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits) powerpc: Fix unrecoverable SLB miss during restore_math() powerpc/8xx: Fix do_mtspr_cpu6() build on older compilers powerpc/rcpm: Fix build break when SMP=n powerpc/book3e-64: Use hardcoded mttmr opcode powerpc/fsl/dts: Add "jedec,spi-nor" flash compatible powerpc/T104xRDB: add tdm riser card node to device tree powerpc32: PAGE_EXEC required for inittext powerpc/mpc85xx: Add pcsphy nodes to FManV3 device tree powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s) powerpc/86xx: Introduce and use common dtsi powerpc/86xx: Update device tree powerpc/86xx: Move dts files to fsl directory powerpc/86xx: Switch to kconfig fragments approach powerpc/86xx: Update defconfigs powerpc/86xx: Consolidate common platform code powerpc32: Remove one insn in mulhdu powerpc32: small optimisation in flush_icache_range() powerpc: Simplify test in __dma_sync() powerpc32: move xxxxx_dcache_range() functions inline powerpc32: Remove clear_pages() and define clear_page() inline ...
| | * cxlflash: Use new cxl_pci_read_adapter_vpd() APIFrederic Barrat2016-03-091-16/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To read the adapter VPD, drivers can't rely on pci config APIs, as it wouldn't work on powerVM. cxl introduced a new kernel API especially for this, so start using it. Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | cxlflash: Move to exponential back-off when cmd_room is not availableManoj N. Kumar2016-03-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While profiling the cxlflash_queuecommand() path under a heavy load it was found that number of retries to find cmd_room was fairly high. There are two problems with the current back-off: a) It starts with a udelay of 0 b) It backs-off linearly Tried several approaches (a higher multiple 10*n, 100*n, as well as n^2, 2^n) and found that the exponential back-off(2^n) approach had the least overall cost. Cost as being defined as overall time spent waiting. The fix is to change the linear back-off to an exponential back-off. This solution also takes care of the problem with the initial delay (starts with 1 usec). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* | | cxlflash: Fix regression issue with re-ordering patchManoj N. Kumar2016-03-281-39/+91
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running 'sg_reset -H' back to back the following exception was seen: [ 735.115695] Faulting instruction address: 0xd0000000098c0864 cpu 0x0: Vector: 300 (Data Access) at [c000000ffffafa80] pc: d0000000098c0864: cxlflash_async_err_irq+0x84/0x5c0 [cxlflash] lr: c00000000013aed0: handle_irq_event_percpu+0xa0/0x310 sp: c000000ffffafd00 msr: 9000000000009033 dar: 2010000 dsisr: 40000000 current = 0xc000000001510880 paca = 0xc00000000fb80000 softe: 0 irq_happened: 0x01 pid = 0, comm = swapper/0 Linux version 4.5.0-491-26f710d+ enter ? for help [c000000ffffafe10] c00000000013aed0 handle_irq_event_percpu+0xa0/0x310 [c000000ffffafed0] c00000000013b1a8 handle_irq_event+0x68/0xc0 [c000000ffffaff00] c0000000001404ec handle_fasteoi_irq+0xec/0x2a0 [c000000ffffaff30] c00000000013a084 generic_handle_irq+0x54/0x80 [c000000ffffaff60] c000000000011130 __do_irq+0x80/0x1d0 [c000000ffffaff90] c000000000024d40 call_do_irq+0x14/0x24 [c000000001573a20] c000000000011318 do_IRQ+0x98/0x140 [c000000001573a70] c000000000002594 hardware_interrupt_common+0x114/0x180 This exception is being hit because the async_err interrupt path performs an MMIO to read the interrupt status register. The MMIO region in this case is not available. Commit 6ded8b3cbd9a ("cxlflash: Unmap problem state area before detaching master context") re-ordered the sequence in which term_mc() and stop_afu() are called. This introduces a window for interrupts to come in with the problem space area unmapped, that did not exist previously. The fix is to separate the disabling of all AFU interrupts to a distinct function, term_intr() so that it is the first thing that is done in the tear down process. To keep the initialization process symmetric, separate the AFU interrupt setup also to a distinct function: init_intr(). Fixes: 6ded8b3cbd9a ("cxlflash: Unmap problem state area before detaching master context") Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* | cxlflash: Increase cmd_per_lun for better throughputManoj N. Kumar2016-03-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the current value of cmd_per_lun at 16, the throughput over a single adapter is limited to around 150kIOPS. Increase the value of cmd_per_lun to 256 to improve throughput. With this change a single adapter is able to attain close to the maximum throughput (380kIOPS). Also change the number of RRQ entries that can be queued. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* | cxlflash: Fix to avoid unnecessary scan with internal LUNsManoj N. Kumar2016-03-081-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When switching to the internal LUN defined on the IBM CXL flash adapter, there is an unnecessary scan occurring on the second port. This scan leads to the following extra lines in the log: Dec 17 10:09:00 tul83p1 kernel: [ 3708.561134] cxlflash 0008:00:00.0: cxlflash_queuecommand: (scp=c0000000fc1f0f00) 11/1/0/0 cdb=(A0000000-00000000-10000000-00000000) Dec 17 10:09:00 tul83p1 kernel: [ 3708.561147] process_cmd_err: cmd failed afu_rc=32 scsi_rc=0 fc_rc=0 afu_extra=0xE, scsi_extra=0x0, fc_extra=0x0 By definition, both of the internal LUNs are on the first port/channel. When the lun_mode is switched to internal LUN the same value for host->max_channel is retained. This causes an unnecessary scan over the second port/channel. This fix alters the host->max_channel to 0 (1 port), if internal LUNs are configured and switches it back to 1 (2 ports) while going back to external LUNs. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* | cxlflash: Unmap problem state area before detaching master contextUma Krishnan2016-03-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When operating in the PowerVM environment, the cxlflash module can receive an error from the hypervisor indicating that there are existing mappings in the page table for the process MMIO space. This issue exists because term_afu() currently invokes term_mc() before stop_afu(), allowing for the master context to be detached first and the problem state area to be unmapped second. To resolve this issue, stop_afu() should be called before term_mc(). 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>
* | cxlflash: Simplify PCI registrationManoj N. Kumar2016-03-081-53/+1
|/ | | | | | | | | | | | | | | | | | | | | | | The calls to pci_request_regions(), pci_resource_start(), pci_set_dma_mask(), pci_set_master() and pci_save_state() are all unnecessary for the IBM CXL flash adapter since data buffers are not required to be mapped to the device's memory. The use of services such as pci_set_dma_mask() are problematic on hypervisor managed systems as the IBM CXL flash adapter is operating under a virtual PCI Host Bridge (virtual PHB) which does not support these services. cxlflash 0001:00:00.0: init_pci: Failed to set PCI DMA mask rc=-5 The resolution is to simplify init_pci(), to a point where it does the bare minimum (pci_enable_device). Similarly, remove the call the pci_release_regions() from cxlflash_remove(). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* cxlflash: Enable device id for future IBM CXL adapterManoj Kumar2016-01-061-0/+3
| | | | | | | | | | | | | | | | | | This drop enables a future card with a device id of 0x0600 to be recognized by the cxlflash driver. As per the design, the Accelerator Function Unit (AFU) for this new IBM CXL Flash Adapter retains the same host interface as the previous generation. For the early prototypes of the new card, the driver with this change behaves exactly as the driver prior to this behaved with the earlier generation card. Therefore, no card specific programming has been added. These card specific changes can be staged in later if needed. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* cxlflash: Resolve oops in wait_port_offlineManoj Kumar2016-01-061-3/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an async error interrupt is generated, and the error requires the FC link to be reset, it cannot be performed in the interrupt context. So a work element is scheduled to complete the link reset in a process context. If either an EEH event or an escalation occurs in between when the interrupt is generated and the scheduled work is started, the MMIO space may no longer be available. This will cause an oops in the worker thread. [ 606.806583] NIP kthread_data+0x28/0x40 [ 606.806633] LR wq_worker_sleeping+0x30/0x100 [ 606.806694] Call Trace: [ 606.806721] 0x50 (unreliable) [ 606.806796] wq_worker_sleeping+0x30/0x100 [ 606.806884] __schedule+0x69c/0x8a0 [ 606.806959] schedule+0x44/0xc0 [ 606.807034] do_exit+0x770/0xb90 [ 606.807109] die+0x300/0x460 [ 606.807185] bad_page_fault+0xd8/0x150 [ 606.807259] handle_page_fault+0x2c/0x30 [ 606.807338] wait_port_offline.constprop.12+0x60/0x130 [cxlflash] To prevent the problem space area from being unmapped, when there is pending work, a mapcount (using the kref mechanism) is held. The mapcount is released only when the work is completed. The last reference release is tied to the unmapping service. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* cxlflash: Fix to resolve cmd leak after host resetManoj Kumar2016-01-061-2/+17
| | | | | | | | | | | | | | | | | | | | | | | After a few iterations of resetting the card, either during EEH recovery, or a host_reset the following is seen in the logs. cxlflash 0008:00: cxlflash_queuecommand: could not get a free command At every reset of the card, the commands that are outstanding are being leaked. No effort is being made to reap these commands. A few more resets later, the above error message floods the logs and the card is rendered totally unusable as no free commands are available. Iterated through the 'cmd' queue and printed out the 'free' counter and found that on each reset certain commands were in-use and stayed in-use through subsequent resets. To resolve this issue, when the card is reset, reap all the commands that are active/outstanding. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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