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path: root/drivers/misc/cxl/native.c
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2016-05-20Merge tag 'powerpc-4.7-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Highlights: - Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V - Live patching support for ppc64le (also merged via livepatching.git) Various cleanups & minor fixes from: - Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie, Lennart Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Michael Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras, Rashmica Gupta, Russell Currey, Suraj Jitindar Singh, Thiago Jung Bauermann, Valentin Rothberg, Vipin K Parashar. General: - Update LMB associativity index during DLPAR add/remove from Nathan Fontenot - Fix branching to OOL handlers in relocatable kernel from Hari Bathini - Add support for userspace Power9 copy/paste from Chris Smart - Always use STRICT_MM_TYPECHECKS from Michael Ellerman - Add mask of possible MMU features from Michael Ellerman PCI: - Enable pass through of NVLink to guests from Alexey Kardashevskiy - Cleanups in preparation for powernv PCI hotplug from Gavin Shan - Don't report error in eeh_pe_reset_and_recover() from Gavin Shan - Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan - Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" from Guilherme G Piccoli - Remove the dependency on EEH struct in DDW mechanism from Guilherme G Piccoli selftests: - Test cp_abort during context switch from Chris Smart - Add several tests for transactional memory support from Rashmica Gupta perf: - Add support for sampling interrupt register state from Anju T - Add support for unwinding perf-stackdump from Chandan Kumar cxl: - Configure the PSL for two CAPI ports on POWER8NVL from Philippe Bergheaud - Allow initialization on timebase sync failures from Frederic Barrat - Increase timeout for detection of AFU mmio hang from Frederic Barrat - Handle num_of_processes larger than can fit in the SPA from Ian Munsie - Ensure PSL interrupt is configured for contexts with no AFU IRQs from Ian Munsie - Add kernel API to allow a context to operate with relocate disabled from Ian Munsie - Check periodically the coherent platform function's state from Christophe Lombard Freescale: - Updates from Scott: "Contains 86xx fixes, minor device tree fixes, an erratum workaround, and a kconfig dependency fix." * tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (192 commits) powerpc/86xx: Fix PCI interrupt map definition powerpc/86xx: Move pci1 definition to the include file powerpc/fsl: Fix build of the dtb embedded kernel images powerpc/fsl: Fix rcpm compatible string powerpc/fsl: Remove FSL_SOC dependency from FSL_LBC powerpc/fsl-pci: Add a workaround for PCI 5 errata powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb powerpc/powernv/npu: Add PE to PHB's list powerpc/powernv: Fix insufficient memory allocation powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" powerpc/eeh: Drop unnecessary label in eeh_pe_change_owner() powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover() powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover() powerpc/eeh: Don't report error in eeh_pe_reset_and_recover() Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()" powerpc/powernv/npu: Enable NVLink pass through powerpc/powernv/npu: Rework TCE Kill handling powerpc/powernv/npu: Add set/unset window helpers powerpc/powernv/ioda2: Export debug helper pe_level_printk() ...
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>
2016-05-11cxl: Handle num_of_processes larger than can fit in the SPAIan Munsie
num_of_process is a 16 bit field, theoretically allowing an AFU to support 16K processes, however the scheduled process area currently has a maximum size of 1MB, which limits the maximum number of processes to 7704. Some AFUs may not necessarily care what the limit is and just want to be able to use the maximum by setting the field to 16K. To allow these to work, detect this situation and use the maximum size for the SPA. Downgrade the WARN_ON to a dev_warn. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-27cxl: Poll for outstanding IRQs when detaching a contextMichael Neuling
When detaching contexts, we may still have interrupts in the system which are yet to be delivered to any CPU and be acked in the PSL. This can result in a subsequent unrelated process getting an spurious IRQ or an interrupt for a non-existent context. This polls the PSL to ensure that the PSL is clear of IRQs for the detached context, before removing the context from the idr. Signed-off-by: Michael Neuling <mikey@neuling.org> Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Tested-by: Vaibhav Jain <vaibhav@linux.vnet.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: 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: Separate bare-metal fields in adapter and AFU data structuresChristophe Lombard
Introduce sub-structures containing the bare-metal specific fields in the structures describing the adapter (struct cxl) and AFU (struct cxl_afu). Update all their references. 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: New hcalls to support cxl adaptersChristophe Lombard
The hypervisor calls provide an interface with a coherent platform facility and function. It matches version 0.16 of the 'PAPR changes' document. The following hcalls are supported: H_ATTACH_CA_PROCESS Attach a process element to a coherent platform function. H_DETACH_CA_PROCESS Detach a process element from a coherent platform function. H_CONTROL_CA_FUNCTION Allow the partition to manipulate or query certain coherent platform function behaviors. H_COLLECT_CA_INT_INFO Collect interrupt info about a coherent. platform function after an interrupt occurred H_CONTROL_CA_FAULTS Control the operation of a coherent platform function after a fault occurs. H_DOWNLOAD_CA_FACILITY Support for downloading a base adapter image to the coherent platform facility, and for validating the entire image after the download. H_CONTROL_CA_FACILITY Allow the partition to manipulate or query certain coherent platform facility behaviors. 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: Rename some bare-metal specific functionsFrederic Barrat
Rename a few functions, changing the 'cxl_' prefix to either 'cxl_pci_' or 'cxl_native_', to make clear that the implementation is bare-metal specific. Those functions will have an equivalent implementation for a guest in a later patch. 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: Introduce implementation-specific APIFrederic Barrat
The backend API (in cxl.h) lists some low-level functions whose implementation is different on bare-metal and in a guest. Each environment implements its own functions, and the common code uses them through function pointers, defined in cxl_backend_ops 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: Move bare-metal specific code to specialized filesFrederic Barrat
Move a few functions around to better separate code specific to bare-metal environment from code which will be commonly used between guest and bare-metal. Code specific to bare-metal is meant to be in native.c or pci.c only. It's basically anything which touches the card p1 registers, some p2 registers not needed from a guest and the PCI interface. 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: Move common code away from bare-metal-specific filesChristophe Lombard
Move around some functions which will be accessed from the bare-metal and guest environments. Code in native.c and pci.c is meant to be bare-metal specific. Other files contain code which may be shared with guests. 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>
2015-12-08cxl: Set endianess of kernel contextsFrederic Barrat
A process element (defined in CAIA) keeps track of the endianess of contexts through the Little Endian (LE) bit of the State Register. It is currently set for user contexts, but was somehow forgotten for kernel contexts, so this patch fixes it. It could lead to erratic behavior from an AFU when the context is attached through the kernel API. Fixes: 2f663527bd6a ("cxl: Configure PSL for kernel contexts and merge code") Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Suggested-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-07cxl: Fix number of allocated pages in SPAChristophe Lombard
The scheduled process area is currently allocated before assigning the correct maximum processes to the AFU, which will mean we only ever allocate a fixed number of pages for the scheduled process area. This will limit us to 958 processes with 2 x 64K pages. If we try to use more processes than that we'd probably overrun the buffer and corrupt memory or crash. AFUs that require three or more interrupts per process will not be affected as they are already limited to less processes than that, but we could hit it on an AFU that requires 0, 1 or 2 interrupts per process, or when using 4K pages. This patch moves the initialisation of the num_procs to before the SPA allocation so that enough pages will be allocated for the number of processes that the AFU supports. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Cc: <stable@vger.kernel.org> # 3.18+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-14cxl: Allocate and release the SPA with the AFUDaniel Axtens
Previously the SPA was allocated and freed upon entering and leaving AFU-directed mode. This causes some issues for error recovery - contexts hold a pointer inside the SPA, and they may persist after the AFU has been detached. We would ideally like to allocate the SPA when the AFU is allocated, and release it until the AFU is released. However, we don't know how big the SPA needs to be until we read the AFU descriptor. Therefore, restructure the code: - Allocate the SPA only once, on the first attach. - Release the SPA only when the entire AFU is being released (not detached). Guard the release with a NULL check, so we don't free if it was never allocated (e.g. dedicated mode) Acked-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-14cxl: Drop commands if the PCI channel is not in normal stateDaniel Axtens
If the PCI channel has gone down, don't attempt to poke the hardware. We need to guard every time cxl_whatever_(read|write) is called. This is because a call to those functions will dereference an offset into an mmio register, and the mmio mappings get invalidated in the EEH teardown. Check in the read/write functions in the header. We give them the same semantics as usual PCI operations: - a write to a channel that is down is ignored. - a read from a channel that is down returns all fs. Also, we try to access the MMIO space of a vPHB device as part of the PCI disable path. Because that's a read that bypasses most of our usual checks, we handle it explicitly. As far as user visible warnings go: - Check link state in file ops, return -EIO if down. - Be reasonably quiet if there's an error in a teardown path, or when we already know the hardware is going down. - Throw a big WARN if someone tries to start a CXL operation while the card is down. This gives a useful stacktrace for debugging whatever is doing that. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-06cxl: Don't ignore add_process_element() result when attaching contextDaniel Axtens
Currently when attaching a context in dedicated mode, we ignore the result of add_process_element(), which could potentially fail. If add_process_element() returns an error, pass it back to the caller. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-13cxl: use more common format specifierRasmus Villemoes
A precision of 16 (%.16llx) has the same effect as a field width of 16 along with passing the 0 flag (%016llx), but the latter is much more common in the kernel tree. Update cxl to use that. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> 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 Neuling
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>
2015-06-03cxl: Configure PSL for kernel contexts and merge codeMichael Neuling
This updates AFU directed and dedicated modes for contexts attached to the kernel. The SR (similar to the MSR in the core) calculation is getting quite complex and is duplicated in AFU directed and dedicated modes. This patch also merges this SR calculation for these modes. 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: Export some symbolsMichael Neuling
Export some symbols which will soon be used elsewhere in this driver. Now they are global we rename them so to avoid collisions. 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: cxl_afu_reset() -> __cxl_afu_reset()Michael Neuling
Rename cxl_afu_reset() to __cxl_afu_reset() to we can reuse this function name in the 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>
2015-01-22cxl: Add tracepointsIan Munsie
This patch adds tracepoints throughout the cxl driver, which can provide insight into: - Context lifetimes - Commands sent to the PSL and AFU and their completion status - Segment and page table misses and their resolution - PSL and AFU interrupts - slbia calls from the powerpc copro_fault code These tracepoints are mostly intended to aid in debugging (particularly for new AFU designs), and may be useful standalone or in conjunction with hardware traces collected by the PSL (read out via the trace interface in debugfs) and AFUs. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-29cxl: Disable SPAP register when freeing SPAIan Munsie
When we deactivate the AFU directed mode we free the scheduled process area, but did not clear the register in the hardware that has a pointer to it. This should be fine since we will have already cleared out every context and we won't do anything that would cause the hardware to access it until after we have allocated a new one, but just to be safe this patch clears out the register when we free the page. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-12cxl: Add timeout to process element commandsIan Munsie
In the event that something goes wrong in the hardware and it is unable to complete a process element comment we would end up polling forever, effectively making the associated process unkillable. This patch adds a timeout to the process element command code path, so that we will give up if the hardware does not respond in a reasonable time. Cc: stable@vger.kernel.org Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-12-12cxl: Change contexts_lock to a mutex to fix sleep while atomic bugIan Munsie
We had a known sleep while atomic bug if a CXL device was forcefully unbound while it was in use. This could occur as a result of EEH, or manually induced with something like this while the device was in use: echo 0000:01:00.0 > /sys/bus/pci/drivers/cxl-pci/unbind The issue was that in this code path we iterated over each context and forcefully detached it with the contexts_lock spin lock held, however the detach also needed to take the spu_mutex, and call schedule. This patch changes the contexts_lock to a mutex so that we are not in atomic context while doing the detach, thereby avoiding the sleep while atomic. Also delete the related TODO comment, which suggested an alternate solution which turned out to not be workable. Cc: stable@vger.kernel.org Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-18cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warningIan Munsie
If an AFU has a hardware bug that causes it to acknowledge a context terminate or remove while that context has outstanding transactions, it is possible for the kernel to receive an interrupt for that context after we have removed it from the context list. The kernel will not be able to demultiplex the interrupt (or worse - if we have already reallocated the process handle we could mis-attribute it to the new context), and printed a big scary warning. It did not acknowledge the interrupt, which would effectively halt further translation fault processing on the PSL. This patch makes the warning clearer about the likely cause of the issue (i.e. hardware bug) to make it obvious to future AFU designers of what needs to be fixed. It also prints out the process handle which can then be matched up with hardware and software traces for debugging. It also acknowledges the interrupt to the PSL with either an address error or acknowledge, so that the PSL can continue with other translations. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-28cxl: Disable secondary hash in segment tableIan Munsie
This patch simplifies the process of finding a free segment table entry by disabling the secondary hash. This reduces the number of possible entries in the segment table for a given address from 16 to 8. Due to the large segment sizes we use it is extremely unlikely that the secondary hash would ever have been used in practice, so this should not have any negative impacts and may even improve performance due to the reduced number of comparisons that software & hardware need to perform. This patch clears the SC bit in the hardware's state register (CXL_PSL_SR_An) to disable the secondary hash in the hardware since we can no longer fill out entries using it. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08cxl: Driver code for powernv PCIe based cards for userspace accessIan Munsie
This is the core of the cxl driver. It adds support for using cxl cards in the powernv environment only (ie POWER8 bare metal). It allows access to cxl accelerators by userspace using the /dev/cxl/afuM.N char devices. The kernel driver has no knowledge of the function implemented by the accelerator. It provides services to userspace via the /dev/cxl/afuM.N devices. When a program opens this device and runs the start work IOCTL, the accelerator will have coherent access to that processes memory using the same virtual addresses. That process may mmap the device to access any MMIO space the accelerator provides. Also, reads on the device will allow interrupts to be received. These services are further documented in a later patch in Documentation/powerpc/cxl.txt. Documentation of the cxl hardware architecture and userspace API is provided in subsequent patches. 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>