- 18 Apr, 2018 39 commits
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Uma Krishnan authored
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>
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Uma Krishnan authored
This commit enables the OCXL operations for the OCXL devices. Signed-off-by:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by:
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Uma Krishnan authored
Use the PCI VPD services to support reading the VPD data of the underlying adapter. Signed-off-by:
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Uma Krishnan authored
The AFU should be enabled following a successful configuration and disabled near the end of the cleanup path. Signed-off-by:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
On a PERST, the AFU image can be reloaded or left intact. Provide means to set this image reload policy. Signed-off-by:
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Uma Krishnan authored
Provide means to obtain the process element of an adapter context as well as locate an adapter context by file. Signed-off-by:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Uma Krishnan authored
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:
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Matthew R. Ochs authored
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:
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Uma Krishnan authored
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:
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- 16 Apr, 2018 1 commit
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Linus Torvalds authored
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