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2018-04-18scsi: cxlflash: Support image reload policy modificationUma Krishnan2-0/+14
On a PERST, the AFU image can be reloaded or left intact. Provide means to set this image reload policy. 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>
2018-04-18scsi: cxlflash: Support adapter context discoveryUma Krishnan1-0/+26
Provide means to obtain the process element of an adapter context as well as locate an adapter context by file. 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>
2018-04-18scsi: cxlflash: Support adapter file descriptors for OCXLUma Krishnan2-0/+201
Allocate a file descriptor for an adapter context when requested. In order to allocate inodes for the file descriptors, a pseudo filesystem is created and used. 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>
2018-04-18scsi: cxlflash: Use IDR to manage adapter contextsUma Krishnan2-2/+21
A range of PASIDs are used as identifiers for the adapter contexts. These contexts may be destroyed and created randomly. Use an IDR to keep track of contexts that are in use and assign a unique identifier to new ones. 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>
2018-04-18scsi: cxlflash: Adapter context support for OCXLUma Krishnan2-0/+96
Add support to create and release the adapter contexts for OCXL and provide means to specify certain contexts as a master. The existing cxlflash core has a design requirement that each host will have a single host context available by default. To satisfy this requirement, one host adapter context is created when the hardware AFU is initialized. This is returned by the get_context() fop. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-18scsi: cxlflash: Setup AFU PASIDUma Krishnan2-0/+4
Per the OCXL specification, the maximum PASID supported by the AFU is indicated by a field within the configuration space. Similar to acTags, implementations can choose to use any sub-range of PASID within their assigned range. For cxlflash, the entire range is used. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-18scsi: cxlflash: Setup AFU acTag rangeUma Krishnan2-0/+15
The OCXL specification supports distributing acTags amongst different AFUs and functions on the link. As cxlflash devices are expected to only support a single AFU per function, the entire range that was assigned to the function is also assigned to the AFU. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-18scsi: cxlflash: Read host AFU configurationUma Krishnan2-0/+39
The host AFU configuration is read on the initialization path to identify the features and configuration of the AFU. This data is cached for use in later configuration steps. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-18scsi: cxlflash: Setup function acTag rangeUma Krishnan2-0/+18
The OCXL specification supports distributing acTags amongst different AFUs and functions on the link. The platform-specific acTag range for the link is obtained using the OCXL provider services and then assigned to the host function based on implementation. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-18scsi: cxlflash: Read host function configurationUma Krishnan2-0/+48
Per the OCXL specification, the underlying host can have multiple AFUs per function with each function supporting its own configuration. The host function configuration is read on the initialization path to evaluate the number of functions present and identify the features and configuration of the functions present. This data is cached for use in later configuration steps. Note that for the OCXL hardware supported by the cxlflash driver, only one AFU per function is expected. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-18scsi: cxlflash: Hardware AFU for OCXLUma Krishnan5-2/+73
When an adapter is initialized, transport specific configuration and MMIO mapping details need to be saved. For CXL, this data is managed by the underlying kernel module. To maintain a separation between the cxlflash core and underlying transports, introduce a new structure to store data specific to the OCXL AFU. Initially only the pointers to underlying PCI and generic devices are added to this new structure - it will be expanded further in future commits. Services to create and destroy this hardware AFU are added and integrated in the probe and exit paths of the driver. Signed-off-by: Uma Krishnan <ukrishn@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>
2018-04-18scsi: cxlflash: Introduce OCXL backendUma Krishnan4-2/+25
Add initial infrastructure to support a new cxlflash transport, OCXL. Claim a dependency on OCXL and add a new file, ocxl_hw.c, which will host the backend routines that are specific to OCXL. Signed-off-by: Uma Krishnan <ukrishn@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>
2018-04-18scsi: cxlflash: Add argument identifier namesUma Krishnan2-24/+27
Checkpatch throws a warning when the argument identifier names are not included in the function definitions. To avoid these warnings, argument identifiers are added in the existing function definitions. 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>
2018-04-18scsi: cxlflash: Avoid clobbering context control register valueMatthew R. Ochs2-1/+5
The SISLite specification originally defined the context control register with a single field of bits to represent the LISN and also stipulated that the register reset value be 0. The cxlflash driver took advantage of this when programming the LISN for the master contexts via an unconditional write - no other bits were preserved. When unmap support was added, SISLite was updated to define bit 0 of the context control register as a way for the AFU to notify the context owner that unmap operations were supported. Thus the assumptions under which the register is setup changed and the existing unconditional write is clobbering the unmap state for master contexts. This is presently not an issue due to the order in which the context control register is programmed in relation to the unmap bit being queried but should be addressed to avoid a future regression in the event this code is moved elsewhere. To remedy this issue, preserve the bits when programming the LISN field in the context control register. Since the LISN will now be programmed using a read value, assert that the initial state of the LISN field is as described in SISLite (0). 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>
2018-04-18scsi: cxlflash: Preserve number of interrupts for master contextsUma Krishnan2-3/+9
The number of interrupts requested for user contexts are stored in the context specific structures and utilized to manage the interrupts. For the master contexts, this number is only used once and therefore not saved. To prepare for future commits where the number of interrupts will be required in more than one place, preserve the value in the master context structure. [mkp: typo in comment] 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>
2018-01-10scsi: cxlflash: Staging to support future acceleratorsMatthew R. Ochs6-78/+263
As staging to support future accelerator transports, add a shim layer such that the underlying services the cxlflash driver requires can be conditional upon the accelerator infrastructure. 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>
2018-01-10scsi: cxlflash: Adapter context init can return errorUma Krishnan1-1/+1
Adapter context creation can return either NULL or an error pointer. Updating the check condition to reflect this. 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>
2018-01-10scsi: cxlflash: Remove embedded CXL work structuresMatthew R. Ochs4-11/+10
The CXL-specific work structure used to request the number of interrupts currently resides as a nested member of both the context information and hardware queue structures. It is used to cache values (specifically the number of interrupts) required by the CXL layer when starting a context. To facilitate staging that will ultimately allow the cxlflash core to become agnostic of the underlying accelerator transport, remove these embedded work structures. 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>
2018-01-10scsi: cxlflash: Explicitly cache number of interrupts per contextMatthew R. Ochs2-5/+10
The number of interrupts a user requests during a context attach is presently stored within the CXL work ioctl structure that is nested alongside the per context metadata. Keeping this data in a structure that is tied to a particular hardware implementation (CXL) will only complicate matters when supporting newer accelerator transports. Instead of relying upon the number of interrupts being cached within a CXL-specific structure, explicitly cache the value within the context information structure. 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>
2018-01-10scsi: cxlflash: Update cxl-specific arguments to generic cookieUma Krishnan4-30/+29
Convert cxl-specific pointers to generic cookies to facilitate future enhancements. 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>
2018-01-10scsi: cxlflash: Reset command ioascUma Krishnan1-0/+1
In the event of a command failure, cxlflash returns the failure to the upper layers to process. After processing the error, when the command is queued again, the private command structure will not be zeroed and the ioasc could be stale. Per the SISLite specification, the AFU only sets the ioasc in the presence of a failure. Thus, even though the original command succeeds the second time, the command is considered a failure due to stale ioasc. This cycle repeats indefinitely and can cause a hang or IO failure. To fix the issue, clear the ioasc before queuing any command. [mkp: added Cc: stable per request] Fixes: 479ad8e9d48c ("scsi: cxlflash: Remove zeroing of private command data") Cc: <stable@vger.kernel.org> 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>
2017-11-17Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-6/+0
Pull compat and uaccess updates from Al Viro: - {get,put}_compat_sigset() series - assorted compat ioctl stuff - more set_fs() elimination - a few more timespec64 conversions - several removals of pointless access_ok() in places where it was followed only by non-__ variants of primitives * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits) coredump: call do_unlinkat directly instead of sys_unlink fs: expose do_unlinkat for built-in callers ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs() ipmi: get rid of pointless access_ok() pi433: sanitize ioctl cxlflash: get rid of pointless access_ok() mtdchar: get rid of pointless access_ok() r128: switch compat ioctls to drm_ioctl_kernel() selection: get rid of field-by-field copyin VT_RESIZEX: get rid of field-by-field copyin i2c compat ioctls: move to ->compat_ioctl() sched_rr_get_interval(): move compat to native, get rid of set_fs() mips: switch to {get,put}_compat_sigset() sparc: switch to {get,put}_compat_sigset() s390: switch to {get,put}_compat_sigset() ppc: switch to {get,put}_compat_sigset() parisc: switch to {get,put}_compat_sigset() get_compat_sigset() get rid of {get,put}_compat_itimerspec() io_getevents: Use timespec64 to represent timeouts ...
2017-10-31scsi: cxlflash: Derive pid through accessorsMatthew R. Ochs1-3/+3
The cxlflash driver tracks process IDs alongside contexts to validate context ownership. Currently, the process IDs are derived by directly accessing values from the 'current' task pointer. While this method of access is fine for the current process, it is incorrect when the parent process ID is needed as the access requires serialization. To address the incorrect issue and provide a consistent means of deriving the process ID within the cxlflash driver, use the task accessors defined linux/sched.h. 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>
2017-10-31scsi: cxlflash: Allow cards without WWPN VPD to configureMatthew R. Ochs2-8/+19
Currently, all adapters that cxlflash supports must have WWPN VPD keywords to complete configuration. This was required as cards with external FC ports needed to be programmed with WWPNs. Newer supported cards do not have an external FC interface and therefore do not require WWPN. To support backwards compatibility, these devices have included 'dummy' WWPN VPD with WWPN values of zero. This however places a dependency that all future cards have WWPN VPD, which may not always be the case. Allow for cards to not have WWPN, designating which cards are expected to have it in order to configure properly. 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>
2017-10-31scsi: cxlflash: Use derived maximum write same lengthMatthew R. Ochs2-5/+4
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>
2017-10-17cxlflash: get rid of pointless access_ok()Al Viro1-6/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-08-25scsi: cxlflash: Fix vlun resize failure in the shrink pathUma Krishnan1-5/+1
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>
2017-08-25scsi: cxlflash: Avoid double mutex unlockMatthew R. Ochs1-3/+10
The AFU recovery routine uses an interruptible mutex to control the flow of in-flight recoveries. Upon receiving an interruptible signal the code branches to a common exit path which wrongly assumes the mutex is held. Add a local variable to track when the mutex should be unlocked. 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: Remove unnecessary existence checkMatthew R. Ochs1-2/+1
The AFU termination sequence has been refactored over time such that the main tear down routine, term_afu(), can no longer can be invoked with a NULL AFU pointer. Remove the unnecessary existence check from term_afu(). 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>
2017-08-24scsi: cxlflash: Fix an error handling path in 'cxlflash_disk_attach()'Christophe JAILLET1-0/+1
'rc' is known to be 0 at this point. If 'create_context()' fails, returns -ENOMEM instead of 0 which means success. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-07-12scsi: cxlflash: return -EFAULT if copy_from_user() failsDan Carpenter1-4/+7
The copy_from/to_user() functions return the number of bytes remaining to be copied but we had intended to return -EFAULT here. Fixes: bc88ac47d5cb ("scsi: cxlflash: Support AFU debug") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-07-01scsi: cxlflash: Update debug prints in reset handlersMatthew R. Ochs1-15/+3
The device and host reset handler contain debug prints to help identify the entities being reset. Today these reset handlers are based on a SCSI EH design that uses a SCSI command reference as a means of identifying the target entity. As such, the debug trace includes the SCSI command pointer and associated CDB. This is not necessary as the SCSI command is simply the messenger in these scenarios. Refactor the debug prints in the host and reset handlers to only present information that is applicable given the function scope. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-07-01scsi: cxlflash: Update send_tmf() parametersMatthew R. Ochs1-14/+13
The current send_tmf() implementation is based on the caller providing a SCSI command reference. In reality all that is needed is a SCSI device reference as the routine uses a private command. Refactor send_tmf() to pass the private adapter configuration reference and a SCSI device reference. As a nice side effect, this will ease the burden of converting caller routines to be based solely off of a SCSI device reference. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-07-01scsi: cxlflash: Avoid double free of character deviceMatthew R. Ochs1-1/+0
The device_unregister() service used when cleaning up the character device is already responsible for the internal state associated with the device upon successful creation. As the cxlflash driver does not obtain a second reference to the character device, the explicit call to put_device() is not required and can lead to an inconsistent sysfs among other issues as the reference is no longer valid after the first put_device() is performed. Remove the unnecessary put_device() to remedy this issue. Fixes: a834a36b57d9 ("scsi: cxlflash: Create character device to provide host management interface") Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-06-26scsi: cxlflash: Update TMF command processingMatthew R. Ochs1-21/+44
Currently, the SCSI command presented to the device reset handler is used to send TMFs to the AFU for a device reset. This behavior is incorrect as the command presented is an actual command and not a special notification. As such, it should only be used for reference and not be acted upon. Additionally, the existing TMF transmission routine does not account for actual errors from the hardware, only reflecting failure when a timeout occurs. This can lead to a condition where the device reset handler is presented with a false 'success'. Update send_tmf() to dynamically allocate a private command for sending the TMF command and properly reflect failure when the completed command indicates an error or was aborted. Detect TMF commands during response processing and avoid scsi_done() for these types of commands. Lastly, update comments in the TMF processing paths to describe the new behavior. 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: Remove zeroing of private command dataMatthew R. Ochs2-3/+10
The SCSI core now zeroes the per-command private data area prior to calling into the LLD. Replace the clearing operation that takes place when the private command data reference is obtained with a routine that performs common initializations. The zeroing that takes place in the device reset path remains intact as the private command data associated with the specified SCSI command is not guaranteed to be cleared. 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: Support WS16 unmapMatthew R. Ochs4-0/+15
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: Support AFU debugMatthew R. Ochs4-0/+104
Adopt the SISLite AFU debug capability to allow future CXL Flash adapters the ability to better debug AFU issues. Update the SISLite header with the changes necessary to support AFU debug operations and create a host ioctl interface for user debug software. Also update the cxlflash documentation to describe this new host ioctl. 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: Support LUN provisioningMatthew R. Ochs4-4/+135
Adopt the SISLite AFU LUN provisioning capability to allow future CXL Flash adapters the ability to better manage storage. Update the SISLite header with the changes necessary to support LUN provision operations and create a host ioctl interface for user LUN management software. Also update the cxlflash documentation to describe this new host ioctl. 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: Refactor AFU capability checkingMatthew R. Ochs1-4/+4
The existing AFU capability checking infrastructure is closely tied to the command mode capability bits. In order to support new capabilities, refactor the existing infrastructure to be more generic. 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: Introduce host ioctl supportMatthew R. Ochs1-1/+120
As staging for supporting various host management functions, add a host ioctl infrastructure to filter ioctl commands and perform operations that are common for all host ioctls. Also update the cxlflash documentation to create a new section for documenting host ioctls. 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: Separate AFU internal command handling from AFU sync specificsMatthew R. Ochs2-28/+53
To date the only supported internal AFU command is AFU sync. The logic to send an internal AFU command is embedded in the specific AFU sync handler and would need to be duplicated for new internal AFU commands. In order to support new internal AFU commands, separate code that is common for AFU internal commands into a generic transmission routine and support passing back command status through an IOASA structure. The first user of this new routine is the existing AFU sync command. As a cleanup, use a descriptive name for the AFU sync command instead of a magic number. 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: Create character device to provide host management interfaceUma Krishnan3-2/+212
The cxlflash driver currently lacks host management interface. Future devices supported by cxlflash will provide a variety of host-wide management functions. Examples include LUN provisioning, hardware debug support, and firmware download. In order to provide a way to manage the device, a character device will be created during probe of each adapter. This device will support a set of ioctls defined in the SISLite specification from which administrators can manage the adapter. 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>
2017-06-26scsi: cxlflash: Add scsi command abort handlerUma Krishnan1-0/+61
To date, CXL flash devices do not support a single command abort operation. Instead, the SISLite specification provides a context reset operation to cleanup all pending commands for a given context. When a context reset is successful, it is guaranteed that the AFU has aborted all currently pending I/O. This sequence is less invasive than a device or host reset and can be executed to support scsi command abort requests. Add eh_abort_handler callback support to process command timeouts and abort requests. 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>
2017-06-26scsi: cxlflash: Flush pending commands in cleanup pathUma Krishnan2-5/+57
When the AFU is reset in an error path, pending scsi commands can be silently dropped without completion or a formal abort. This puts the onus on the cxlflash driver to notify mid-layer and indicating that the command can be retried. Once the card has been quiesced, the hardware send queue lock is acquired to prevent any data movement while the pending commands are processed. 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>
2017-06-26scsi: cxlflash: Track pending scsi commands in each hardware queueUma Krishnan2-0/+11
Currently, there is no book keeping of the pending scsi commands in the cxlflash driver. This lack of tracking in-flight requests is too restrictive and requires a heavy-hammer reset each time an adapter error is encountered. Additionally, it does not allow for commands to be properly retried. In order to avoid this problem and to better handle error path command cleanup, introduce a linked list for each hardware queue that tracks pending commands. 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>
2017-06-26scsi: cxlflash: Handle AFU sync failuresUma Krishnan2-27/+95
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>
2017-06-26scsi: cxlflash: Schedule asynchronous reset of the hostUma Krishnan2-35/+104
A context reset failure indicates the AFU is in a bad state. At present, when such a situation occurs, no further action is taken. This leaves the adapter in an unusable state with no recoverable actions. To avoid this situation, context reset failures will be escalated to a host reset operation. This will be done asynchronously to allow the acting thread to return to the user with a 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>
2017-06-26scsi: cxlflash: Reset hardware queue context via specified registerUma Krishnan2-38/+47
Per the SISLite specification, context_reset() writes 0x1 to the LSB of the reset register. When the AFU processes this reset request, it is expected to clear the bit after reset is complete. The current implementation simply checks that the entire value read back is not 1, instead of masking off the LSB and evaluating it for a change to 0. Should the AFU manipulate other bits during the reset (reading back a value of 0xF for example), successful completion will be prematurely indicated given the existing logic. Additionally, in the event that the context reset operation fails, there does not currently exist a way to provide feedback to the initiator of the reset. This poses a problem for the rare case that a context reset fails as the caller will proceed on the assumption that all is well. To remedy these issues, refactor the context reset routine to only mask off the LSB when evaluating for success and return status to the caller. Also update the context reset handler parameters to pass a hardware queue reference instead of a single command to better reflect that the entire queue associated with the context is impacted by the reset. 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>
2017-06-26scsi: cxlflash: Update cxlflash_afu_sync() to return errnoUma Krishnan1-5/+6
The cxlflash_afu_sync() routine returns a negative one to indicate any kind of failure. This makes it impossible to establish why the error occurred. Update the return codes to clearly indicate the failure cause to the caller. 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>