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2018-05-18scsi: cxlflash: Isolate external module dependenciesUma Krishnan7-7/+16
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>
2018-05-18scsi: cxlflash: Abstract hardware dependent assignmentsUma Krishnan2-5/+17
As a staging cleanup to support transport specific builds of the cxlflash module, relocate device dependent assignments to header files. This will avoid littering the core driver with conditional compilation logic. 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>
2018-05-18scsi: cxlflash: Add include guards to backend.hUma Krishnan1-0/+5
The new header file, backend.h, that was recently added is missing the include guards. This commit adds the guards. 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>
2018-05-18scsi: cxlflash: Use local mutex for AFU serializationMatthew R. Ochs2-3/+4
AFUs can only process a single AFU command at a time. This is enforced with a global mutex situated within the AFU send routine. As this mutex has a global scope, it has the potential to unnecessarily block commands destined for other AFUs. Instead of using a global mutex, transition the mutex to be per-AFU. This will allow commands to only be blocked by siblings of the same 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>
2018-05-18scsi: cxlflash: Acquire semaphore before invoking ioctl servicesUma Krishnan1-0/+6
When a superpipe process that makes use of virtual LUNs is terminated or killed abruptly, there is a possibility that the cxlflash driver could hang and deprive other operations on the adapter. The release fop registered to be invoked on a context close, detaches every LUN associated with the context. The underlying service to detach the LUN assumes it has been called with the read semaphore held, and releases the semaphore before any operation that could be time consuming. When invoked without holding the read semaphore, an opportunity is created for the semaphore's count to become negative when it is temporarily released during one of these potential lengthy operations. This negative count results in subsequent acquisition attempts taking forever, leading to the hang. To support the current design point of holding the semaphore on the ioctl() paths, the release fop should acquire it before invoking any ioctl services. 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>
2018-05-18scsi: cxlflash: Limit the debug logs in the IO pathUma Krishnan1-2/+2
The kernel log can get filled with debug messages from send_cmd_ioarrin() when dynamic debug is enabled for the cxlflash module and there is a lot of legacy I/O traffic. While these messages are necessary to debug issues that involve command tracking, the abundance of data can overwrite other useful data in the log. The best option available is to limit the messages that should serve most of the common use cases. 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>
2018-05-18scsi: cxlflash: Yield to active send threadsUma Krishnan1-0/+2
The following Oops may be encountered if the device is reset, i.e. EEH recovery, while there is heavy I/O traffic: 59:mon> t [c000200db64bb680] c008000009264c40 cxlflash_queuecommand+0x3b8/0x500 [cxlflash] [c000200db64bb770] c00000000090d3b0 scsi_dispatch_cmd+0x130/0x2f0 [c000200db64bb7f0] c00000000090fdd8 scsi_request_fn+0x3c8/0x8d0 [c000200db64bb900] c00000000067f528 __blk_run_queue+0x68/0xb0 [c000200db64bb930] c00000000067ab80 __elv_add_request+0x140/0x3c0 [c000200db64bb9b0] c00000000068daac blk_execute_rq_nowait+0xec/0x1a0 [c000200db64bba00] c00000000068dbb0 blk_execute_rq+0x50/0xe0 [c000200db64bba50] c0000000006b2040 sg_io+0x1f0/0x520 [c000200db64bbaf0] c0000000006b2e94 scsi_cmd_ioctl+0x534/0x610 [c000200db64bbc20] c000000000926208 sd_ioctl+0x118/0x280 [c000200db64bbcc0] c00000000069f7ac blkdev_ioctl+0x7fc/0xe30 [c000200db64bbd20] c000000000439204 block_ioctl+0x84/0xa0 [c000200db64bbd40] c0000000003f8514 do_vfs_ioctl+0xd4/0xa00 [c000200db64bbde0] c0000000003f8f04 SyS_ioctl+0xc4/0x130 [c000200db64bbe30] c00000000000b184 system_call+0x58/0x6c When there is no room to send the I/O request, the cached room is refreshed by reading the memory mapped command room value from the AFU. The AFU register mapping is refreshed during a reset, creating a race condition that can lead to the Oops above. During a device reset, the AFU should not be unmapped until all the active send threads quiesce. An atomic counter, cmds_active, is currently used to track internal AFU commands and quiesce during reset. This same counter can also be used for the active send threads. 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: Handle spurious interruptsUma Krishnan2-0/+12
The following Oops can occur when there is heavy I/O traffic and the host is reset by a tool such as sg_reset. [c000200fff3fbc90] c00800001690117c process_cmd_doneq+0x104/0x500 [cxlflash] (unreliable) [c000200fff3fbd80] c008000016901648 cxlflash_rrq_irq+0xd0/0x150 [cxlflash] [c000200fff3fbde0] c000000000193130 __handle_irq_event_percpu+0xa0/0x310 [c000200fff3fbea0] c0000000001933d8 handle_irq_event_percpu+0x38/0x90 [c000200fff3fbee0] c000000000193494 handle_irq_event+0x64/0xb0 [c000200fff3fbf10] c000000000198ea0 handle_fasteoi_irq+0xc0/0x230 [c000200fff3fbf40] c00000000019182c generic_handle_irq+0x4c/0x70 [c000200fff3fbf60] c00000000001794c __do_irq+0x7c/0x1c0 [c000200fff3fbf90] c00000000002a390 call_do_irq+0x14/0x24 [c000200e5828fab0] c000000000017b2c do_IRQ+0x9c/0x130 [c000200e5828fb00] c000000000009b04 h_virt_irq_common+0x114/0x120 When a context is reset, the pending commands are flushed and the AFU is notified. Before the AFU handles this request there could be command completion interrupts queued to PHB which are yet to be delivered to the context. In this scenario, a context could receive an interrupt for a command that has been flushed, leading to a possible crash when the memory for the flushed command is accessed. To resolve this problem, a boolean will indicate if the hardware queue is ready to process interrupts or not. This can be evaluated in the interrupt handler before proessing an 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>
2018-04-18scsi: cxlflash: Remove commmands from pending list on timeoutUma Krishnan1-0/+14
The following Oops can occur if an internal command sent to the AFU does not complete within the timeout: [c000000ff101b810] c008000016020d94 term_mc+0xfc/0x1b0 [cxlflash] [c000000ff101b8a0] c008000016020fb0 term_afu+0x168/0x280 [cxlflash] [c000000ff101b930] c0080000160232ec cxlflash_pci_error_detected+0x184/0x230 [cxlflash] [c000000ff101b9e0] c00800000d95d468 cxl_vphb_error_detected+0x90/0x150[cxl] [c000000ff101ba20] c00800000d95f27c cxl_pci_error_detected+0xa4/0x240 [cxl] [c000000ff101bac0] c00000000003eaf8 eeh_report_error+0xd8/0x1b0 [c000000ff101bb20] c00000000003d0b8 eeh_pe_dev_traverse+0x98/0x170 [c000000ff101bbb0] c00000000003f438 eeh_handle_normal_event+0x198/0x580 [c000000ff101bc60] c00000000003fba4 eeh_handle_event+0x2a4/0x338 [c000000ff101bd10] c0000000000400b8 eeh_event_handler+0x1f8/0x200 [c000000ff101bdc0] c00000000013da48 kthread+0x1a8/0x1b0 [c000000ff101be30] c00000000000b528 ret_from_kernel_thread+0x5c/0xb4 When an internal command times out, the command buffer is freed while it is still in the pending commands list of the context. This corrupts the list and when the context is cleaned up, a crash is encountered. To resolve this issue, when an AFU command or TMF command times out, the command should be deleted from the hardware queue pending command list before freeing the buffer. 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: Synchronize reset and remove opsUma Krishnan1-3/+3
The following Oops can be encountered if a device removal or system shutdown is initiated while an EEH recovery is in process: [c000000ff2f479c0] c008000015256f18 cxlflash_pci_slot_reset+0xa0/0x100 [cxlflash] [c000000ff2f47a30] c00800000dae22e0 cxl_pci_slot_reset+0x168/0x290 [cxl] [c000000ff2f47ae0] c00000000003ef1c eeh_report_reset+0xec/0x170 [c000000ff2f47b20] c00000000003d0b8 eeh_pe_dev_traverse+0x98/0x170 [c000000ff2f47bb0] c00000000003f80c eeh_handle_normal_event+0x56c/0x580 [c000000ff2f47c60] c00000000003fba4 eeh_handle_event+0x2a4/0x338 [c000000ff2f47d10] c0000000000400b8 eeh_event_handler+0x1f8/0x200 [c000000ff2f47dc0] c00000000013da48 kthread+0x1a8/0x1b0 [c000000ff2f47e30] c00000000000b528 ret_from_kernel_thread+0x5c/0xb4 The remove handler frees AFU memory while the EEH recovery is in progress, leading to a race condition. This can result in a crash if the recovery thread tries to access this memory. To resolve this issue, the cxlflash remove handler will evaluate the device state and yield to any active reset or probing threads. 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: Enable OCXL operationsUma Krishnan2-2/+8
This commit enables the OCXL operations for the OCXL devices. 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 AFU resetUma Krishnan1-0/+17
The cxlflash core driver resets the AFU when the master contexts are created in the initialization or recovery paths. Today, the OCXL provider service to perform this operation is pending implementation. To avoid a crash due to a missing fop, log an error once and return success to continue with execution. 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: Register for translation errorsUma Krishnan2-2/+33
While enabling a context on the link, a predefined callback can be registered with the OCXL provider services to be notified on translation errors. These errors can in turn be passed back to the user on a read operation. 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: Introduce OCXL context state machineUma Krishnan2-3/+64
In order to protect the OCXL hardware contexts from getting clobbered, a simple state machine is added to indicate when a context is in open, close or start state. The expected states are validated throughout the code to prevent illegal operations on a context. A mutex is added to protect writes to the context state field. 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: Update synchronous interrupt status bitsUma Krishnan1-14/+21
The SISLite specification has been updated to define new synchronous interrupt status bits. These bits are set by the AFU when a given PASID or EA is bad and a synchronous interrupt is triggered. The SISLite header file is updated to support these new bits. Note that there are also some formatting updates to some of the existing bits to allow all of the definitions to line up uniformly. 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: Setup LISNs for master contextsUma Krishnan1-0/+21
Similar to user contexts, master contexts also require that the per-context LISN registers be programmed for certain AFUs. The mapped trigger page is obtained from underlying transport and registered with AFU for each master context. 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: Setup LISNs for user contextsUma Krishnan3-0/+24
The SISLite specification has been updated for OCXL to support communicating data to generate AFU interrupts to the AFU. This includes a new capability bit that is advertised for OCXL AFUs and new registers to hold the object handle and translation PASID of each interrupt. For Power, the object handle is the mapped trigger page. Note that because these mappings are kernel only, the PASID of a kernel context must be used to satisfy the translation. 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: Introduce object handle fopUma Krishnan3-0/+26
OCXL requires that AFUs use an opaque object handle to represent an AFU interrupt. The specification does not provide a common means to communicate the object handle to the AFU - each AFU must define this within the AFU specification. To support this model, the object handle must be passed back to the core driver as it manages the AFU specification (SISLite) for cxlflash. Note that for Power systems, the object handle is the effective address of the trigger page. 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 file descriptor mappingUma Krishnan1-0/+26
The cxlflash core fop API requires a way to invoke the fault and release handlers of underlying transports using their native file-based APIs. This provides the core with the ability to insert selectively itself into the processing stream of these operations for cleanup. Implement these two fops to map and release when requested. 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 mmap and releaseUma Krishnan1-0/+72
The cxlflash userspace API requires that users be able to mmap and release the adapter context. Support mapping by implementing the AFU mmap fop to map the context MMIO space and install the corresponding page table entry upon page fault. Similarly, implement the AFU release fop to terminate and clean up the context when invoked. 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 readingUma Krishnan1-0/+94
The cxlflash userspace API requires that users be able to read the adapter context for any pending events or interrupts from the AFU. Support reading various events by implementing the AFU read fop to copy out event data. 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 pollingUma Krishnan2-2/+57
The cxlflash userspace API requires that users be able to poll the adapter context for any pending events or interrupts from the AFU. Support polling on various events by implementing the AFU poll fop using a waitqueue. 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 starting user contextsUma Krishnan2-2/+100
User contexts request interrupts and are started using the "start work" interface. Populate the start_work() fop to allocate and map interrupts before starting the user context. As part of starting the context, update the user process identification logic to properly derive the data required by the SPA. Also, introduce a skeleton interrupt handler using a bitmap, flag, and spinlock to track interrupts. This handler will be expanded in future commits. 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 AFU interrupt mapping and registrationUma Krishnan2-0/+122
Add support to map and unmap the irq space and manage irq registrations with the kernel for each allocated AFU interrupt. Also support mapping the physical trigger page to obtain an effective address that will be provided to the cxlflash core in a future commit. 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 AFU interrupt managementUma Krishnan2-0/+114
Add support to allocate and free AFU interrupts using the OCXL provider services. The trigger page returned upon successful allocation will be mapped and exposed to the cxlflash core in a future commit. 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 process element lifecycleUma Krishnan1-2/+50
As part of the context lifecycle, the associated process element within the Shared Process Area (SPA) of the link must be updated. Each process is defined by various parameters (pid, tid, PASID mm) that are stored in the SPA upon starting a context and invalidated when a context is stopped. Use the OCXL provider services to configure the SPA with the appropriate data that is unique to the process when starting a context. Initially only kernel contexts are supported and therefore these process values are not applicable. Note that the OCXL service used has an optional callback for translation fault error notification. While not used here, it will be expanded in a future commit. Also add a service to stop a context by terminating the corresponding PASID and remove the process element from the SPA. 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: Setup OCXL transaction layerUma Krishnan1-0/+10
The first function of the link needs to configure the transaction layer between the host and device. This is accomplished by a call to the OCXL provider services. 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: Setup function OCXL linkUma Krishnan2-3/+23
After reading and modifying the function configuration, setup the OCXL link using the OCXL provider services. The link is released when the adapter is unconfigured. 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: Support reading adapter VPD dataUma Krishnan1-0/+15
Use the PCI VPD services to support reading the VPD data of the underlying 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>
2018-04-18scsi: cxlflash: Support AFU state togglingUma Krishnan1-0/+9
The AFU should be enabled following a successful configuration and disabled near the end of the cleanup path. 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: Support process specific mappingsUma Krishnan1-0/+24
Once the context is started, the assigned MMIO space can be mapped and unmapped. Provide means to map and unmap the context MMIO space. 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 starting an adapter contextUma Krishnan2-0/+42
Once the adapter context is created, it needs to be started by assigning the MMIO space for the context and by enabling the process element in the link. This commit adds the skeleton for starting the context and assigns the context specific MMIO space. Master contexts have access to the global MMIO space while the rest have access to the context specific space. 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: MMIO map the AFUUma Krishnan2-1/+77
When the AFU is configured, the global and per process MMIO regions are presented by the configuration space. Save these regions and map the global MMIO region that is used to access all of the control and provisioning data in the AFU. 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: 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>