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path: root/drivers/misc/cxl/guest.c
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2017-04-13cxl: Add psl9 specific codeChristophe Lombard
The new Coherent Accelerator Interface Architecture, level 2, for the IBM POWER9 brings new content and features: - POWER9 Service Layer - Registers - Radix mode - Process element entry - Dedicated-Shared Process Programming Model - Translation Fault Handling - CAPP - Memory Context ID If a valid mm_struct is found the memory context id is used for each transaction associated with the process handle. The PSL uses the context ID to find the corresponding process element. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> [mpe: Fixup comment formatting, unsplit long strings] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-13cxl: Rename some psl8 specific functionsChristophe Lombard
Rename a few functions, changing the '_psl' suffix to '_psl8', to make clear that the implementation is psl8 specific. Those functions will have an equivalent implementation for the psl9 in a later patch. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-13cxl: Update implementation service layerChristophe Lombard
The service layer API (in cxl.h) lists some low-level functions whose implementation is different on PSL8, PSL9 and XSL: - Init implementation for the adapter and the afu. - Invalidate TLB/SLB. - Attach process for dedicated/directed models. - Handle psl interrupts. - Debug registers for the adapter and the afu. - Traces. Each environment implements its own functions, and the common code uses them through function pointers, defined in cxl_service_layer_ops. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-23cxl: Fix coccinelle warningsAndrew Donnellan
Fix the following coccinelle warnings: drivers/misc/cxl/debugfs.c:46:0-23: WARNING: fops_io_x64 should be defined with DEFINE_DEBUGFS_ATTRIBUTE drivers/misc/cxl/guest.c:890:5-26: WARNING: Comparison to bool drivers/misc/cxl/irq.c:107:3-23: WARNING: Assignment of bool to 0/1 drivers/misc/cxl/native.c:57:2-3: Unneeded semicolon drivers/misc/cxl/native.c:170:2-3: Unneeded semicolon Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19cxl: Prevent adapter reset if an active context existsVaibhav Jain
This patch prevents resetting the cxl adapter via sysfs in presence of one or more active cxl_context on it. This protects against an unrecoverable error caused by PSL owning a dirty cache line even after reset and host tries to touch the same cache line. In case a force reset of the card is required irrespective of any active contexts, the int value -1 can be stored in the 'reset' sysfs attribute of the card. The patch introduces a new atomic_t member named contexts_num inside struct cxl that holds the number of active context attached to the card , which is checked against '0' before proceeding with the reset. To prevent against a race condition where a context is activated just after reset check is performed, the contexts_num is atomically set to '-1' after reset-check to indicate that no more contexts can be activated on the card anymore. Before activating a context we atomically test if contexts_num is non-negative and if so, increment its value by one. In case the value of contexts_num is negative then it indicates that the card is about to be reset and context activation is error-ed out at that point. Fixes: 62fa19d4b4fd ("cxl: Add ability to reset the card") Cc: stable@vger.kernel.org # v4.0+ Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-19cxl: fix potential NULL dereference in free_adapter()Andrew Donnellan
If kzalloc() fails when allocating adapter->guest in cxl_guest_init_adapter(), we call free_adapter() before erroring out. free_adapter() in turn attempts to dereference adapter->guest, which in this case is NULL. In free_adapter(), skip the adapter->guest cleanup if adapter->guest is NULL. Fixes: 14baf4d9c739 ("cxl: Add guest-specific code") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-08cxl: Refine slice error debug messagesPhilippe Bergheaud
The PSL Slice Error Register (PSL_SERR_An) reports implementation dependent AFU errors, in the form of a bitmap. The PSL_SERR_An register content is printed in the form of hex dump debug message. This patch decodes the PSL_ERR_An register contents, and prints a specific error message for each possible error bit. It also dumps the secondary registers AFU_ERR_An and PSL_DSISR_An, that may contain extra debug information. This patch also removes the large WARN message that used to report the cxl slice error interrupt, and replaces it by a short informative message, that draws attention to AFU implementation errors. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-16cxl: Update process element after allocating interruptsIan Munsie
In the kernel API, it is possible to attempt to allocate AFU interrupts after already starting a context. Since the process element structure used by the hardware is only filled out at the time the context is started, it will not be updated with the interrupt numbers that have just been allocated and therefore AFU interrupts will not work unless they were allocated prior to starting the context. This can present some difficulties as each CAPI enabled PCI device in the kernel API has a default context, which may need to be started very early to enable translations, potentially before interrupts can easily be set up. This patch makes the API more flexible to allow interrupts to be allocated after a context has already been started and takes care of updating the PE structure used by the hardware and notifying it to discard any cached copy it may have. The update is currently performed via a terminate/remove/add sequence. This is necessary on some hardware such as the XSL that does not properly support the update LLCMD. Note that this is only supported on powernv at present - attempting to perform this ordering on PowerVM will raise a warning. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11cxl: Check periodically the coherent platform function's stateChristophe Lombard
In the PowerVM environment, the PHYP CoherentAccel component manages the state of the Coherent Accelerator Processor Interface adapter and virtualizes CAPI resources, handles CAPP, PSL, PSL Slice errors - and interrupts - and provides a new set of hcalls for the OS APIs to utilize Accelerator Function Unit (AFU). During the course of operation, a coherent platform function can encounter errors. Some possible reason for errors are: • Hardware recoverable and unrecoverable errors • Transient and over-threshold correctable errors PHYP implements its own state model for the coherent platform function. The state of the AFU is available through a hcall. The current implementation of the cxl driver, for the PowerVM environment, checks this state of the AFU only when an action is requested - open a device, ioctl command, memory map, attach/detach a process - from an external driver - cxlflash, libcxl. If an error is detected the cxl driver handles the error according the content of the Power Architecture Platform Requirements document. But in case of low-level troubles (or error injection), the PHYP component may reset the card and change the AFU state. The PHYP interface doesn't provide any way to be notified when that happens thus implies that the cxl driver: • cannot handle immediatly the state change of the AFU. • cannot notify other drivers (cxlflash, ...) The purpose of this patch is to wake up the cpu periodically to check the current state of each AFU and to see if we need to enter an error recovery path. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11cxl: Add kernel API to allow a context to operate with relocate disabledIan Munsie
cxl devices typically access memory using an MMU in much the same way as the CPU, and each context includes a state register much like the MSR in the CPU. Like the CPU, the state register includes a bit to enable relocation, which we currently always enable. In some cases, it may be desirable to allow a device to access memory using real addresses instead of effective addresses, so this adds a new API, cxl_set_translation_mode, that can be used to disable relocation on a given kernel context. This can allow for the creation of a special privileged context that the device can use if it needs relocation disabled, and can use regular contexts at times when it needs relocation enabled. This interface is only available to users of the kernel API for obvious reasons, and will never be supported in a virtualised environment. This will be used by the upcoming cxl support in the mlx5 driver. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-11cxl: Ensure PSL interrupt is configured for contexts with no AFU IRQsIan Munsie
In the cxl kernel API, it is possible to create a context and start it without allocating any interrupts. Since we assign or allocate the PSL interrupt when allocating AFU interrupts this will lead to a situation where we start the context with no means to take any faults. The user API is not affected as it always goes through the cxl interrupt allocation code paths and will have the PSL interrupt allocated or assigned, even if no AFU interrupts were requested. This checks that at least one interrupt is configured at the time of attach, and if not it will assign the multiplexed PSL interrupt for powernv, or allocate a single interrupt for PowerVM. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-22cxl: Allow initialization on timebase sync failuresFrederic Barrat
Failure to synchronize the PSL timebase currently prevents the initialization of the cxl card, thus rendering the card useless. This is too extreme for a feature which is rarely used, if at all. No hardware AFUs or software is currently using PSL timebase. This patch still tries to synchronize the PSL timebase when the card is initialized, but ignores the error if it can't. Instead, it reports a status via /sys. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Adapter failure handlingChristophe Lombard
Check the AFU state whenever an API is called. The hypervisor may issue a reset of the adapter when it detects a fault. When it happens, it launches an error recovery which will either move the AFU to a permanent failure state, or in the disabled state. If the AFU is found to be disabled, detach all existing contexts from it before issuing a AFU reset to re-enable it. Before detaching contexts, notify any kernel driver through the EEH callbacks of the AFU pci device. Co-authored-by: Frederic Barrat <fbarrat@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: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Support the cxl kernel API from a guestFrederic Barrat
Like on bare-metal, the cxl driver creates a virtual PHB and a pci device for the AFU. The configuration space of the device is mapped to the configuration record of the AFU. Reuse the code defined in afu_cr_read8|16|32() when reading the configuration space of the AFU device. Even though the (virtual) AFU device is a pci device, the adapter is not. So a driver using the cxl kernel API cannot read the VPD of the adapter through the usual PCI interface. Therefore, we add a call to the cxl kernel API: ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count); 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: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Support to flash a new image on the adapter from a guestChristophe Lombard
The new flash.c file contains the logic to flash a new image on the adapter, through a hcall. It is an iterative process, with chunks of data of 1M at a time. There are also 2 phases: write and verify. The flash operation itself is driven from a user-land tool. Once flashing is successful, an rtas call is made to update the device tree with the new properties values for the adapter and the AFU(s) Add a new char device for the adapter, so that the flash tool can access the card, even if there is no valid AFU on it. Co-authored-by: Frederic Barrat <fbarrat@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: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: sysfs support for guestsChristophe Lombard
Filter out a few adapter parameters which don't make sense in a guest. Document the changes. Co-authored-by: Frederic Barrat <fbarrat@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: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09cxl: Add guest-specific codeChristophe Lombard
The new of.c file contains code to parse the device tree to find out about cxl adapters and AFUs. guest.c implements the guest-specific callbacks for the backend API. The process element ID is not known until the context is attached, so we have to separate the context ID assigned by the cxl driver from the process element ID visible to the user applications. In bare-metal, the 2 IDs match. Co-authored-by: Frederic Barrat <fbarrat@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: Manoj Kumar <manoj@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> [mpe: Fix SMP=n build, fix PSERIES=n build, minor whitespace fixes] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>