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2016-07-14cxl: Add cxl_check_and_switch_mode() API to switch bi-modal cardsAndrew Donnellan1-0/+25
Add a new API, cxl_check_and_switch_mode() to allow for switching of bi-modal CAPI cards, such as the Mellanox CX-4 network card. When a driver requests to switch a card to CAPI mode, use PCI hotplug infrastructure to remove all PCI devices underneath the slot. We then write an updated mode control register to the CAPI VSEC, hot reset the card, and reprobe the card. As the card may present a different set of PCI devices after the mode switch, use the infrastructure provided by the pnv_php driver and the OPAL PCI slot management facilities to ensure that: * the old devices are removed from both the OPAL and Linux device trees * the new devices are probed by OPAL and added to the OPAL device tree * the new devices are added to the Linux device tree and probed through the regular PCI device probe path As such, introduce a new option, CONFIG_CXL_BIMODAL, with a dependency on the pnv_php driver. Refactor existing code that touches the mode control register in the regular single mode case into a new function, setup_cxl_protocol_area(). Co-authored-by: Ian Munsie <imunsie@au1.ibm.com> Cc: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14cxl: Add preliminary workaround for CX4 interrupt limitationIan Munsie1-0/+9
The Mellanox CX4 has a hardware limitation where only 4 bits of the AFU interrupt number can be passed to the XSL when sending an interrupt, limiting it to only 15 interrupts per context (AFU interrupt number 0 is invalid). In order to overcome this, we will allocate additional contexts linked to the default context as extra address space for the extra interrupts - this will be implemented in the next patch. This patch adds the preliminary support to allow this, by way of adding a linked list in the context structure that we use to keep track of the contexts dedicated to interrupts, and an API to simultaneously iterate over the related context structures, AFU interrupt numbers and hardware interrupt numbers. The point of using a single API to iterate these is to hide some of the details of the iteration from external code, and to reduce the number of APIs that need to be exported via base.c to allow built in code to call. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14cxl: Add kernel APIs to get & set the max irqs per contextIan Munsie1-0/+10
These APIs will be used by the Mellanox CX4 support. While they function standalone to configure existing behaviour, their primary purpose is to allow the Mellanox driver to inform the cxl driver of a hardware limitation, which will be used in a future patch. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14cxl: Add cxl_slot_is_supported APIIan Munsie1-0/+15
This extends the check that the adapter is in a CAPI capable slot so that it may be called by external users in the kernel API. This will be used by the upcoming Mellanox CX4 support, which needs to know ahead of time if the card can be switched to cxl mode so that it can leave it in PCI mode if it is not. This API takes a parameter to check if CAPP DMA mode is supported, which it currently only allows on P8NVL systems, since that mode currently has issues accessing memory < 4GB on P8, and we cannot realistically avoid that. This API does not currently check if a CAPP unit is available (i.e. not already assigned to another PHB) on P8. Doing so would be racy since it is assigned on a first come first serve basis, and so long as CAPP DMA mode is not supported on P8 we don't need this, since the only anticipated user of this API requires CAPP DMA mode. Cc: Philippe Bergheaud <felix@linux.vnet.ibm.com> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-28cxl: Add set and get private data to context structMichael Neuling1-0/+7
This provides AFU drivers a means to associate private data with a cxl context. This is particularly intended for make the new callbacks for driver specific events easier for AFU drivers to use, as they can easily get back to any private data structures they may use. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-28cxl: Add mechanism for delivering AFU driver specific eventsPhilippe Bergheaud1-0/+48
This adds an afu_driver_ops structure with fetch_event() and event_delivered() callbacks. An AFU driver such as cxlflash can fill this out and associate it with a context to enable passing custom AFU specific events to userspace. This also adds a new kernel API function cxl_context_pending_events(), that the AFU driver can use to notify the cxl driver that new specific events are ready to be delivered, and wake up anyone waiting on the context wait queue. The current count of AFU driver specific events is stored in the field afu_driver_events of the context structure. The cxl driver checks the afu_driver_events count during poll, select, read, etc. calls to check if an AFU driver specific event is pending, and calls fetch_event() to obtain and deliver that event. This way, the cxl driver takes care of all the usual locking semantics around these calls and handles all the generic cxl events, so that the AFU driver only needs to worry about it's own events. fetch_event() return a struct cxl_event_afu_driver_reserved, allocated by the AFU driver, and filled in with the specific event information and size. Total event size (header + data) should not be greater than CXL_READ_MIN_SIZE (4K). Th cxl driver prepends an appropriate cxl event header, copies the event to userspace, and finally calls event_delivered() to return the status of the operation to the AFU driver. The event is identified by the context and cxl_event_afu_driver_reserved pointers. Since AFU drivers provide their own means for userspace to obtain the AFU file descriptor (i.e. cxlflash uses an ioctl on their scsi file descriptor to obtain the AFU file descriptor) and the generic cxl driver will never use this event, the ABI of the event is up to each individual AFU driver. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.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 Munsie1-0/+8
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>
2016-03-09cxl: Remove cxl_get_phys_dev() kernel APIFrederic Barrat1-3/+0
The cxl_get_phys_dev() API returns a struct device pointer which could belong to either a struct pci_dev (bare-metal) or platform_device (powerVM). To avoid potential problems in drivers, remove that API. It was introduced to allow drivers to read the VPD of the adapter, but the cxl driver now provides the cxl_pci_read_adapter_vpd() API for that purpose. 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> 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 Barrat1-0/+5
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>
2015-08-14cxl: Allow the kernel to trust that an image won't change on PERST.Daniel Axtens1-0/+10
Provide a kernel API and a sysfs entry which allow a user to specify that when a card is PERSTed, it's image will stay the same, allowing it to participate in EEH. cxl_reset is used to reflash the card. In that case, we cannot safely assert that the image will not change. Therefore, disallow cxl_reset if the flag is set. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03cxl: Add AFU virtual PHB and kernel APIMichael Neuling1-0/+203
This patch does two things. Firstly it presents the Accelerator Function Unit (AFUs) behind the POWER Service Layer (PSL) as PCI devices on a virtual PCI Host Bridge (vPHB). This in in addition to the PSL being a PCI device itself. As part of the Coherent Accelerator Interface Architecture (CAIA) AFUs can provide an AFU configuration. This AFU configuration recored is architected to be the same as a PCI config space. This patch sets discovers the AFU configuration records, provides AFU config space read/write functions to these configuration records. It then enumerates the PCI bus. It also hooks in PCI ops where appropriate. It also destroys the vPHB when the physical card is removed. Secondly, it add an in kernel API for AFU to use CXL. AFUs must present a driver that firstly binds as a PCI device. This PCI device can then be using to do CXL specific operations (that can't sit in the PCI ops) using this API. Signed-off-by: Michael Neuling <mikey@neuling.org> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03cxl: Move include file cxl.h -> cxl-base.hMichael Neuling1-48/+0
This moves the current include file from cxl.h -> cxl-base.h. This current include file is used only to pass information between the base driver that needs to be built into the kernel and the cxl module. This is to make way for a new include/misc/cxl.h which will contain just the kernel API for other driver to use Signed-off-by: Michael Neuling <mikey@neuling.org> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08cxl: Add new header for call backs and structsIan Munsie1-0/+48
This new header adds callbacks and structs needed by the rest of the kernel to hook into the cxl infrastructure. This adds the cxl_ctx_in_use() function for use in the mm code to see if any cxl contexts are currently in use. This is used by the tlbie() to determine if it can do local TLB invalidations or not. This also adds get/put calls for the cxl driver module to refcount the active cxl contexts. cxl_ctx_get/put/in_use are static inlined here as they are called in tlbie which we want to be fast (mpe's suggestion). Empty functions are provided when CONFIG_CXL_BASE is not enabled. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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