summaryrefslogtreecommitdiff
path: root/drivers/misc/cxl/cxl.h
AgeCommit message (Collapse)AuthorFilesLines
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-19Merge branch 'topic/ppc-kvm' into nextMichael Ellerman1-8/+0
Merge in some commits we're sharing with the KVM tree. I manually propagated the change from commit d3d4ffaae439 ("powerpc/powernv/ioda2: Reduce upper limit for DMA window size") into pci-ioda-tce.c. Conflicts: arch/powerpc/include/asm/cputable.h arch/powerpc/platforms/powernv/pci-ioda.c arch/powerpc/platforms/powernv/pci.h
2018-07-16powerpc/64s: Remove POWER9 DD1 supportNicholas Piggin1-8/+0
POWER9 DD1 was never a product. It is no longer supported by upstream firmware, and it is not effectively supported in Linux due to lack of testing. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [mpe: Remove arch_make_huge_pte() entirely] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-02cxl: Remove abandonned capi support for the Mellanox CX4, final cleanupFrederic Barrat1-12/+0
Remove a few XSL/CX4 oddities which are no longer needed. A simple revert of the initial commits was not possible (or not worth it) due to the history of the code. Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-02Revert "cxl: Allow a default context to be associated with an external pci_dev"Frederic Barrat1-6/+0
Remove abandonned capi support for the Mellanox CX4. This reverts commit a19bd79e31769626d288cc016e21a31b6f47bf6f. Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-02Revert "cxl: Add preliminary workaround for CX4 interrupt limitation"Alastair D'Silva1-10/+0
Remove abandonned capi support for the Mellanox CX4. This reverts commit cbce0917e2e47d4bf5aa3b5fd6b1247f33e1a126. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-02Revert "cxl: Add support for interrupts on the Mellanox CX4"Alastair D'Silva1-4/+0
Remove abandonned capi support for the Mellanox CX4. This reverts commit a2f67d5ee8d950caaa7a6144cf0bfb256500b73e. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-02Revert "cxl: Add kernel API to allow a context to operate with relocate ↵Alastair D'Silva1-1/+0
disabled" Remove abandonned capi support for the Mellanox CX4. The symbol 'cxl_set_translation_mode' is never called, so ctx->real_mode is always false. This reverts commit 7a0d85d313c2066712e530e668bc02bb741a685c. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15cxl: Report the tunneled operations statusPhilippe Bergheaud1-0/+1
Failure to synchronize the tunneled operations does not prevent the initialization of the cxl card. This patch reports the tunneled operations status via /sys. Signed-off-by: Philippe Bergheaud <felix@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13cxl: read PHB indications from the device treePhilippe Bergheaud1-1/+1
Configure the P9 XSL_DSNCTL register with PHB indications found in the device tree, or else use legacy hard-coded values. Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13cxl: Check if PSL data-cache is available before issue flush requestVaibhav Jain1-0/+4
PSL9D doesn't have a data-cache that needs to be flushed before resetting the card. However when cxl tries to flush data-cache on such a card, it times-out as PSL_Control register never indicates flush operation complete due to missing data-cache. This is usually indicated in the kernel logs with this message: "WARNING: cache flush timed out" To fix this the patch checks PSL_Debug register CDC-Field(BIT:27) which indicates the absence of a data-cache and sets a flag 'no_data_cache' in 'struct cxl_native' to indicate this. When cxl_data_cache_flush() is called it checks the flag and if set bails out early without requesting a data-cache flush operation to the PSL. Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-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>
2018-02-02Merge tag 'powerpc-4.16-1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Highlights: - Enable support for memory protection keys aka "pkeys" on Power7/8/9 when using the hash table MMU. - Extend our interrupt soft masking to support masking PMU interrupts as well as "normal" interrupts, and then use that to implement local_t for a ~4x speedup vs the current atomics-based implementation. - A new driver "ocxl" for "Open Coherent Accelerator Processor Interface (OpenCAPI)" devices. - Support for new device tree properties on PowerVM to describe hotpluggable memory and devices. - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 64-bit VDSO. - Freescale updates from Scott: fixes for CPM GPIO and an FSL PCI erratum workaround, plus a minor cleanup patch. As well as quite a lot of other changes all over the place, and small fixes and cleanups as always. Thanks to: Alan Modra, Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Anton Blanchard, Arnd Bergmann, Balbir Singh, Benjamin Herrenschmidt, Bhaktipriya Shridhar, Bryant G. Ly, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Cyril Bur, David Gibson, Desnes A. Nunes do Rosario, Dmitry Torokhov, Frederic Barrat, Geert Uytterhoeven, Guilherme G. Piccoli, Gustavo A. R. Silva, Gustavo Romero, Ivan Mikhaylov, Joakim Tjernlund, Joe Perches, Josh Poimboeuf, Juan J. Alvarez, Julia Cartwright, Kamalesh Babulal, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael Bringmann, Michael Hanselmann, Michael Neuling, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud, Ram Pai, Russell Currey, Santosh Sivaraj, Scott Wood, Seth Forshee, Simon Guo, Stewart Smith, Sukadev Bhattiprolu, Thiago Jung Bauermann, Vaibhav Jain, Vasyl Gomonovych" * tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (199 commits) powerpc/mm/radix: Fix build error when RADIX_MMU=n macintosh/ams-input: Use true and false for boolean values macintosh: change some data types from int to bool powerpc/watchdog: Print the NIP in soft_nmi_interrupt() powerpc/watchdog: regs can't be null in soft_nmi_interrupt() powerpc/watchdog: Tweak watchdog printks powerpc/cell: Remove axonram driver rtc-opal: Fix handling of firmware error codes, prevent busy loops powerpc/mpc52xx_gpt: make use of raw_spinlock variants macintosh/adb: Properly mark continued kernel messages powerpc/pseries: Fix cpu hotplug crash with memoryless nodes powerpc/numa: Ensure nodes initialized for hotplug powerpc/numa: Use ibm,max-associativity-domains to discover possible nodes powerpc/kernel: Block interrupts when updating TIDR powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn powerpc/mm/nohash: do not flush the entire mm when range is a single page powerpc/pseries: Add Initialization of VF Bars powerpc/pseries/pci: Associate PEs to VFs in configure SR-IOV powerpc/eeh: Add EEH notify resume sysfs powerpc/eeh: Add EEH operations to notify resume ...
2018-01-19cxl: Add support for ASB_Notify on POWER9Christophe Lombard1-0/+3
The POWER9 core supports a new feature: ASB_Notify which requires the support of the Special Purpose Register: TIDR. The ASB_Notify command, generated by the AFU, will attempt to wake-up the host thread identified by the particular LPID:PID:TID. This patch assign a unique TIDR (thread id) for the current thread which will be used in the process element entry. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-06cxl: Rework the implementation of cxl_stop_trace_psl9()Vaibhav Jain1-10/+4
Presently the PSL9 specific cxl_stop_trace_psl9() only stops the RX0 traces on the CXL adapter when a PSL error irq is triggered. The patch updates the function to stop all the traces arrays and move them to the FIN state. The implementation issues the mmio to TRACECFG register to stop the trace array iff it already not in FIN state. This prevents the issue of trace data being reset in case of multiple stop mmio issued for a single trace array. Also the patch does some refactoring of existing cxl_stop_trace_psl9() and cxl_stop_trace_psl8() functions by moving them to 'pci.c' from 'debugfs.c' file and marking them as static. Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-22cxl: Provide debugfs access to PSL_DEBUG/XSL_DEBUG registersVaibhav Jain1-0/+1
Access to PSL/XSL_DEBUG registers on the adapter provides easy access to the debug facilities provided by PSL/XSL. So this patch adds two new files (debug, xsl-debug) to the cxl-adapter specific debugfs folder located at /sys/kernel/debugfs/cxl/card<n>, which will provide direct r/w access to corrosponding debug registers in the adapter config-space. Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-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>
2017-10-13cxl: Dump PSL_FIR register on PSL9 error irqVaibhav Jain1-1/+2
For PSL9 currently we aren't dumping the PSL FIR register when a PSL error interrupt is triggered. Contents of this register are useful in debugging AFU issues. This patch fixes issue by adding a new service_layer_ops callback cxl_native_err_irq_dump_regs_psl9() to dump the PSL_FIR registers on a PSL error interrupt thereby bringing the behavior in line with PSL on POWER-8. Also the existing service_layer_ops callback for PSL8 has been renamed to cxl_native_err_irq_dump_regs_psl8(). Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-10cxl: Rename register PSL9_FIR2 to PSL9_FIR_MASKVaibhav Jain1-1/+1
PSL9 doesn't have a FIR2 register as was the case with PSL8. However currently the register definitions in 'cxl.h' have a definition for PSL9_FIR2 that actually points to PSL9_FIR_MASK register in the P1 area at offset 0x308. So this patch renames the def PSL9_FIR2 to PSL9_FIR_MASK and updates the references in the code to point to the new identifier. It also removes the code to dump contents of FIR2 (FIR_MASK actually) in cxl_native_irq_dump_regs_psl9(). Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Reported-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-06cxl: Add support for POWER9 DD2Christophe Lombard1-0/+2
The PSL initialization sequence has been updated to DD2. This patch adapts to the changes, retaining compatibility with DD1. The patch includes some changes to DD1 fix-ups as well. Tests performed on some of the old/new hardware. The function is_page_fault(), for POWER9, lists the Translation Checkout Responses where the page fault will be handled by copro_handle_mm_fault(). This list is too restrictive and not necessary. This patches removes this restriction and all page faults, whatever the reason, will be handled. In this case, the interruption is always acknowledged. The following features will be added soon: - phb reset when switching to capi mode. - cxllib update to support new functions. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-03cxl: Export library to support IBM XSLChristophe Lombard1-0/+6
This patch exports a in-kernel 'library' API which can be called by other drivers to help interacting with an IBM XSL on a POWER9 system. The XSL (Translation Service Layer) is a stripped down version of the PSL (Power Service Layer) used in some cards such as the Mellanox CX5. Like the PSL, it implements the CAIA architecture, but has a number of differences, mostly in it's implementation dependent registers. The XSL also uses a special DMA cxl mode, which uses a slightly different init sequence for the CAPP and PHB. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-23cxl: Fixes for Coherent Accelerator Interface Architecture 2.0Christophe Lombard1-13/+5
A previous set of patches "cxl: Add support for Coherent Accelerator Interface Architecture 2.0" has introduced a new support for the CAPI cards. These patches have been tested on Simulation environment and quite a bit of them have been tested on real hardware. This patch brings new fixes after a series of tests carried out on new equipment: - Add POWER9 definition. - Re-enable any masked interrupts when the AFU is not activated after resetting the AFU. - Remove the api cxl_is_psl8/9 which is no longer useful. - Do not dump CAPI1 registers. - Rewrite cxl_is_page_fault() function. - Do not register slb callack on P9. Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-05-02cxl: Mask slice error interrupts after first occurrenceAlastair D'Silva1-0/+18
In some situations, a faulty AFU slice may create an interrupt storm of slice errors, rendering the machine unusable. Since these interrupts are informational only, present the interrupt once, then mask it off to prevent it from being retriggered until the AFU is reset. Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-13cxl: Add psl9 specific codeChristophe Lombard1-18/+120
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: Isolate few psl8 specific callsChristophe Lombard1-8/+27
Point out the specific Coherent Accelerator Interface Architecture, level 1, registers. Code and functions specific to PSL8 (CAIA1) must be framed. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> [mpe: Don't split long strings, it makes them hard to grep for] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-13cxl: Rename some psl8 specific functionsChristophe Lombard1-13/+13
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 Lombard1-12/+28
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>
2017-04-13cxl: Keep track of mm struct associated with a contextChristophe Lombard1-2/+8
The mm_struct corresponding to the current task is acquired each time an interrupt is raised. So to simplify the code, we only get the mm_struct when attaching an AFU context to the process. The mm_count reference is increased to ensure that the mm_struct can't be freed. The mm_struct will be released when the context is detached. A reference on mm_users is not kept to avoid a circular dependency if the process mmaps its cxl mmio and forget to unmap before exiting. The field glpid (pid of the group leader associated with the pid), of the structure cxl_context, is removed because it's no longer useful. 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: Remove unused values in bare-metal environment.Christophe Lombard1-16/+4
The two previously fields pid and tid, located in the structure cxl_irq_info, are only used in the guest environment. To avoid confusion, it's not necessary to fill the fields in the bare-metal environment. Pid_tid is now renamed to 'reserved' to avoid undefined behavior on bare-metal. The PSL Process and Thread Identification Register (CXL_PSL_PID_TID_An) is only used when attaching a dedicated process for PSL8 only. This register goes away in CAIA2. 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>
2017-02-21cxl: fix nested locking hang during EEH hotplugAndrew Donnellan1-2/+3
Commit 14a3ae34bfd0 ("cxl: Prevent read/write to AFU config space while AFU not configured") introduced a rwsem to fix an invalid memory access that occurred when someone attempts to access the config space of an AFU on a vPHB whilst the AFU is deconfigured, such as during EEH recovery. It turns out that it's possible to run into a nested locking issue when EEH recovery fails and a full device hotplug is required. cxl_pci_error_detected() deconfigures the AFU, taking a writer lock on configured_rwsem. When EEH recovery fails, the EEH code calls pci_hp_remove_devices() to remove the device, which in turn calls cxl_remove() -> cxl_pci_remove_afu() -> pci_deconfigure_afu(), which tries to grab the writer lock that's already held. Standard rwsem semantics don't express what we really want to do here and don't allow for nested locking. Fix this by replacing the rwsem with an atomic_t which we can control more finely. Allow the AFU to be locked multiple times so long as there are no readers. Fixes: 14a3ae34bfd0 ("cxl: Prevent read/write to AFU config space while AFU not configured") Cc: stable@vger.kernel.org # v4.9+ Signed-off-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>
2017-02-03cxl: Fix build when CONFIG_DEBUG_FS=nAndrew Donnellan1-4/+55
Stub out the debugfs functions so that the build doesn't break when CONFIG_DEBUG_FS=n. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-25cxl: Prevent read/write to AFU config space while AFU not configuredAndrew Donnellan1-0/+2
During EEH recovery, we deconfigure all AFUs whilst leaving the corresponding vPHB and virtual PCI device in place. If something attempts to interact with the AFU's PCI config space (e.g. running lspci) after the AFU has been deconfigured and before it's reconfigured, cxl_pcie_{read,write}_config() will read invalid values from the deconfigured struct cxl_afu and proceed to Oops when they try to dereference pointers that have been set to NULL during deconfiguration. Add a rwsem to struct cxl_afu so we can prevent interaction with config space while the AFU is deconfigured. Reported-by: Pradipta Ghosh <pradghos@in.ibm.com> Suggested-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v4.9+ Signed-off-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>
2016-11-18cxl: Fix coredump generation when cxl_get_fd() is usedFrederic Barrat1-2/+4
If a process dumps core while owning a cxl file descriptor obtained from an AFU driver (e.g. cxlflash) through the cxl_get_fd() API, the following error occurs: [ 868.027591] Unable to handle kernel paging request for data at address ... [ 868.027778] Faulting instruction address: 0xc00000000035edb0 cpu 0x8c: Vector: 300 (Data Access) at [c000003c688275e0] pc: c00000000035edb0: elf_core_dump+0xd60/0x1300 lr: c00000000035ed80: elf_core_dump+0xd30/0x1300 sp: c000003c68827860 msr: 9000000100009033 dar: c dsisr: 40000000 current = 0xc000003c68780000 paca = 0xc000000001b73200 softe: 0 irq_happened: 0x01 pid = 46725, comm = hxesurelock enter ? for help [c000003c68827a60] c00000000036948c do_coredump+0xcec/0x11e0 [c000003c68827c20] c0000000000ce9e0 get_signal+0x540/0x7b0 [c000003c68827d10] c000000000017354 do_signal+0x54/0x2b0 [c000003c68827e00] c00000000001777c do_notify_resume+0xbc/0xd0 [c000003c68827e30] c000000000009838 ret_from_except_lite+0x64/0x68 --- Exception: 300 (Data Access) at 00003fff98ad2918 The root cause is that the address_space structure for the file doesn't define a 'host' member. When cxl allocates a file descriptor, it's using the anonymous inode to back the file, but allocates a private address_space for each context. The private address_space allows to track memory allocation for each context. cxl doesn't define the 'host' member of the address space, i.e. the inode. We don't want to define it as the anonymous inode, since there's no longer a 1-to-1 relation between address_space and inode. To fix it, instead of using the anonymous inode, we introduce a simple pseudo filesystem so that cxl can allocate its own inodes. So we now have one inode for each file and address_space. The pseudo filesystem is only mounted on the first allocation of a file descriptor by cxl_get_fd(). Tested with cxlflash. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19cxl: Prevent adapter reset if an active context existsVaibhav Jain1-0/+24
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>
2016-10-04cxl: Flush PSL cache before resetting the adapterFrederic Barrat1-1/+5
If the capi link is going down while the PSL owns a dirty cache line, any access from the host for that data could lead to an Uncorrectable Error. So when resetting the capi adapter through sysfs, make sure the PSL cache is flushed. It won't help if there are any active Process Elements on the card, as the cache would likely get new dirty cache lines immediately, but if resetting an idle adapter, it should avoid any bad surprises from data left over from terminated Process Elements. Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-09cxl: Fix NULL dereference in cxl_context_init() on PowerVM guestsAndrew Donnellan1-1/+1
Commit f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4") added a "min_pe" field to struct cxl_service_layer_ops, to allow us to work around a Mellanox CX-4 hardware limitation. When allocating the PE number in cxl_context_init(), we read from ctx->afu->adapter->native->sl_ops->min_pe to get the minimum PE number. Unsurprisingly, in a PowerVM guest ctx->afu->adapter->native is NULL, and guests don't have a cxl_service_layer_ops struct anywhere. Move min_pe from struct cxl_service_layer_ops to struct cxl so it's accessible in both native and PowerVM environments. For the Mellanox CX-4, set the min_pe value in set_sl_ops(). Fixes: f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4") Reported-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-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>
2016-07-14cxl: Workaround PE=0 hardware limitation in Mellanox CX4Ian Munsie1-0/+1
The CX4 card cannot cope with a context with PE=0 due to a hardware limitation, resulting in: [ 34.166577] command failed, status limits exceeded(0x8), syndrome 0x5a7939 [ 34.166580] mlx5_core 0000:01:00.1: Failed allocating uar, aborting Since the kernel API allocates a default context very early during device init that will almost certainly get Process Element ID 0 there is no easy way for us to extend the API to allow the Mellanox to inform us of this limitation ahead of time. Instead, work around the issue by extending the XSL structure to include a minimum PE to allocate. Although the bug is not in the XSL, it is the easiest place to work around this limitation given that the CX4 is currently the only card that uses an XSL. 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>
2016-07-14cxl: Add support for interrupts on the Mellanox CX4Ian Munsie1-0/+4
The Mellanox CX4 in cxl mode uses a hybrid interrupt model, where interrupts are routed from the networking hardware to the XSL using the MSIX table, and from there will be transformed back into an MSIX interrupt using the cxl style interrupts (i.e. using IVTE entries and ranges to map a PE and AFU interrupt number to an MSIX address). We want to hide the implementation details of cxl interrupts as much as possible. To this end, we use a special version of the MSI setup & teardown routines in the PHB while in cxl mode to allocate the cxl interrupts and configure the IVTE entries in the process element. This function does not configure the MSIX table - the CX4 card uses a custom format in that table and it would not be appropriate to fill that out in generic code. The rest of the functionality is similar to the "Full MSI-X mode" described in the CAIA, and this could be easily extended to support other adapters that use that mode in the future. The interrupts will be associated with the default context. If the maximum number of interrupts per context has been limited (e.g. by the mlx5 driver), it will automatically allocate additional kernel contexts to associate extra interrupts as required. These contexts will be started using the same WED that was used to start the default context. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14cxl: Add preliminary workaround for CX4 interrupt limitationIan Munsie1-0/+10
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: Allow a default context to be associated with an external pci_devIan Munsie1-0/+6
The cxl kernel API has a concept of a default context associated with each PCI device under the virtual PHB. The Mellanox CX4 will also use the cxl kernel API, but it does not use a virtual PHB - rather, the AFU appears as a physical function as a peer to the networking functions. In order to allow the kernel API to work with those networking functions, we will need to associate a default context with them as well. To this end, refactor the corresponding code to do this in vphb.c and export it so that it can be called from the PHB code. 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: Move cxl_afu_get / cxl_afu_put to baseIan Munsie1-12/+0
The Mellanox CX4 uses a model where the AFU is one physical function of the device, and is used by other peer physical functions of the same device. This will require those other devices to grab a reference on the AFU when they are initialised to make sure that it does not go away during their lifetime. Move the AFU refcount functions to base.c so they can be called from the PHB code. 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>
2016-07-08cxl: Refine slice error debug messagesPhilippe Bergheaud1-0/+15
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>
2016-07-08cxl: Fix bug where AFU disable operation had no effectIan Munsie1-0/+1
The AFU disable operation has a bug where it will not clear the enable bit and therefore will have no effect. To date this has likely been masked by fact that we perform an AFU reset before the disable, which also has the effect of clearing the enable bit, making the following disable operation effectively a noop on most hardware. This patch modifies the afu_control function to take a parameter to clear from the AFU control register so that the disable operation can clear the appropriate bit. This bug was uncovered on the Mellanox CX4, which uses an XSL rather than a PSL. On the XSL the reset operation will not complete while the AFU is enabled, meaning the enable bit was still set at the start of the disable and as a result this bug was hit and the disable also timed out. Because of this difference in behaviour between the PSL and XSL, this patch now makes the reset dependent on the card using a PSL to avoid waiting for a timeout on the XSL. It is entirely possible that we may be able to drop the reset altogether if it turns out we only ever needed it due to this bug - however I am not willing to drop it without further regression testing and have added comments to the code explaining the background. This also fixes a small issue where the AFU_Cntl register was read outside of the lock that protects it. 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>
2016-06-28cxl: Add set and get private data to context structMichael Neuling1-0/+3
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 Bergheaud1-1/+6
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>
2016-06-16cxl: Add support for CAPP DMA modeIan Munsie1-0/+1
This adds support for using CAPP DMA mode, which is required for XSL based cards such as the Mellanox CX4 to function. This is currently an RFC as it depends on the corresponding support to be merged into skiboot first, which was submitted here: http://patchwork.ozlabs.org/patch/625582/ In the event that the skiboot on the system does not have the above support, it will indicate as such in the kernel log and abort the init process. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-16cxl: Abstract the differences between the PSL and XSLFrederic Barrat1-0/+26
The XSL (Translation Service Layer) is a stripped down version of the PSL (Power Service Layer) used in some cards such as the Mellanox CX4. Like the PSL, it implements the CAIA architecture, but has a number of differences, mostly in it's implementation dependent registers. This adds an ops structure to abstract these differences to bring initial support for XSL CAPI devices. The XSL does not implement the optional architected SERR register, however while it treats it as a reserved register and should work with no special treatment, attempting to access it will cause the XSL_FEC (First Error Capture) register to be filled out, preventing it from capturing any subsequent errors. Therefore, this patch also prevents the kernel from trying to set up the SERR register so that the FEC register may still be useful, and to save one interrupt. The XSL also uses a special DMA cxl mode, which uses a slightly different init sequence for the CAPP and PHB. The kernel support for this will be in a future patch once the corresponding support has been merged into skiboot. Co-authored-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-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 Munsie1-0/+1
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>
2016-05-20Merge tag 'powerpc-4.7-1' of ↵Linus Torvalds1-10/+5
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: Check periodically the coherent platform function's stateChristophe Lombard1-1/+3
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 Munsie1-0/+1
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>