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2022-01-04cxl/core: Remove cxld_const_init in cxl_decoder_alloc()Nathan Chancellor
Commit 48667f676189 ("cxl/core: Split decoder setup into alloc + add") aimed to fix a large stack frame warning but from v5 to v6, it introduced a new instance of the warning due to allocating cxld_const_init on the stack, which was done due to the use of const on the nr_target member of the cxl_decoder struct. With ARCH=arm allmodconfig minus CONFIG_KASAN: GCC 11.2.0: drivers/cxl/core/bus.c: In function ‘cxl_decoder_alloc’: drivers/cxl/core/bus.c:523:1: error: the frame size of 1032 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] 523 | } | ^ cc1: all warnings being treated as errors Clang 12.0.1: drivers/cxl/core/bus.c:486:21: error: stack frame size of 1056 bytes in function 'cxl_decoder_alloc' [-Werror,-Wframe-larger-than=] struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets) ^ 1 error generated. Revert that part of the change, which makes the stack frame of cxl_decoder_alloc() much more reasonable. Fixes: 48667f676189 ("cxl/core: Split decoder setup into alloc + add") Link: https://github.com/ClangBuiltLinux/linux/issues/1539 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20211210213627.2477370-1-nathan@kernel.org Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/pmem: Fix module reload vs workqueue stateDan Williams
A test of the form: while true; do modprobe -r cxl_pmem; modprobe cxl_pmem; done May lead to a crash signature of the form: BUG: unable to handle page fault for address: ffffffffc0660030 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page [..] Workqueue: cxl_pmem 0xffffffffc0660030 RIP: 0010:0xffffffffc0660030 Code: Unable to access opcode bytes at RIP 0xffffffffc0660006. [..] Call Trace: ? process_one_work+0x4ec/0x9c0 ? pwq_dec_nr_in_flight+0x100/0x100 ? rwlock_bug.part.0+0x60/0x60 ? worker_thread+0x2eb/0x700 In that report the 0xffffffffc0660030 address corresponds to the former function address of cxl_nvb_update_state() from a previous load of the module, not the current address. Fix that by arranging for ->state_work in the 'struct cxl_nvdimm_bridge' object to be reinitialized on cxl_pmem module reload. Details: Recall that CXL subsystem wants to link a CXL memory expander device to an NVDIMM sub-hierarchy when both a persistent memory range has been registered by the CXL platform driver (cxl_acpi) *and* when that CXL memory expander has published persistent memory capacity (Get Partition Info). To this end the cxl_nvdimm_bridge driver arranges to rescan the CXL bus when either of those conditions change. The helper bus_rescan_devices() can not be called underneath the device_lock() for any device on that bus, so the cxl_nvdimm_bridge driver uses a workqueue for the rescan. Typically a driver allocates driver data to hold a 'struct work_struct' for a driven device, but for a workqueue that may run after ->remove() returns, driver data will have been freed. The 'struct cxl_nvdimm_bridge' object holds the state and work_struct directly. Unfortunately it was only arranging for that infrastructure to be initialized once per device creation rather than the necessary once per workqueue (cxl_pmem_wq) creation. Introduce is_cxl_nvdimm_bridge() and cxl_nvdimm_bridge_reset() in support of invalidating stale references to a recently destroyed cxl_pmem_wq. Cc: <stable@vger.kernel.org> Fixes: 8fdcb1704f61 ("cxl/pmem: Add initial infrastructure for pmem support") Reported-by: Vishal Verma <vishal.l.verma@intel.com> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/163665474585.3505991.8397182770066720755.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15ACPI: NUMA: Add a node and memblk for each CFMWS not in SRATAlison Schofield
During NUMA init, CXL memory defined in the SRAT Memory Affinity subtable may be assigned to a NUMA node. Since there is no requirement that the SRAT be comprehensive for CXL memory another mechanism is needed to assign NUMA nodes to CXL memory not identified in the SRAT. Use the CXL Fixed Memory Window Structure (CFMWS) of the ACPI CXL Early Discovery Table (CEDT) to find all CXL memory ranges. Create a NUMA node for each CFMWS that is not already assigned to a NUMA node. Add a memblk attaching its host physical address range to the node. Note that these ranges may not actually map any memory at boot time. They may describe persistent capacity or may be present to enable hot-plug. Consumers can use phys_to_target_node() to discover the NUMA node. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/163553711933.2509508.2203471175679990.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/test: Mock acpi_table_parse_cedt()Dan Williams
Now that cxl_acpi has been converted to use the core ACPI CEDT sub-table parser, update cxl_test to inject CFMWS and CHBS data directly into cxl_acpi's handlers. Cc: Alison Schofield <alison.schofield@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/163553711363.2509508.17428994087868269952.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/acpi: Convert CFMWS parsing to ACPI sub-table helpersDan Williams
The cxl_acpi driver originally open-coded its table parsing since the ACPI subtable helpers were marked __init and only used in early NUMA initialization. Now that those helpers have been exported for driver usage replace the open-coded solution with the common one. Cc: Alison Schofield <alison.schofield@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/163553710810.2509508.14686373989517930921.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/memdev: Remove unused cxlmd fieldIra Weiny
This field was left over when the connection between the cxl_memdev and cxl_mem was tighter. It is no longer set nor used so remove it.[1] Link: https://lore.kernel.org/r/CAPcyv4hcgh2gb8qsS_UXTBSGqYfMPnC6p5kkvNUjm+V6kVKM5g@mail.gmail.com/ Suggested-by: Jonathan.Cameron@huawei.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211103234857.3689354-1-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/core: Convert to EXPORT_SYMBOL_NS_GPLDan Williams
It turns out that the usb example of specifying the subsystem namespace at build time is not preferred. The rationale for that preference has become more apparent as CXL patches with plain EXPORT_SYMBOL_GPL beg the question, "why would any code other than CXL care about this symbol?". Make the namespace explicit. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163676356810.3618264.601632777702192938.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/memdev: Change cxl_mem to a more descriptive nameIra Weiny
The 'struct cxl_mem' object actually represents the state of a CXL device within the driver. Comments indicating that 'struct cxl_mem' is a device itself are incorrect. It is data layered on top of a CXL Memory Expander class device. Rename it 'struct cxl_dev_state'. The 'struct' cxl_memdev' structure represents a Linux CXL memory device object, and it uses services and information provided by 'struct cxl_dev_state'. Update the structure name, function names, and the kdocs to reflect the real uses of this structure. Some helper functions that were previously prefixed "cxl_mem_" are renamed to just "cxl_". Acked-by: Ben Widawsky <ben.widawsky@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211102202901.3675568-3-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/mbox: Remove bad commentIra Weiny
__cxl_mem_mbox_send_cmd() no longer exists. Remove the reference. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211102202901.3675568-2-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-15cxl/pmem: Fix reference counting for delayed workDan Williams
There is a potential race between queue_work() returning and the queued-work running that could result in put_device() running before get_device(). Introduce the cxl_nvdimm_bridge_state_work() helper that takes the reference unconditionally, but drops it if no new work was queued, to keep the references balanced. Fixes: 8fdcb1704f61 ("cxl/pmem: Add initial infrastructure for pmem support") Cc: <stable@vger.kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163553734757.2509761.3305231863616785470.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-11-08Merge tag 'cxl-for-5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl updates from Dan Williams: "More preparation and plumbing work in the CXL subsystem. From an end user perspective the highlight here is lighting up the CXL Persistent Memory related commands (label read / write) with the generic ioctl() front-end in LIBNVDIMM. Otherwise, the ability to instantiate new persistent and volatile memory regions is still on track for v5.17. Summary: - Fix support for platforms that do not enumerate every ACPI0016 (CXL Host Bridge) in the CHBS (ACPI Host Bridge Structure). - Introduce a common pci_find_dvsec_capability() helper, clean up open coded implementations in various drivers. - Add 'cxl_test' for regression testing CXL subsystem ABIs. 'cxl_test' is a module built from tools/testing/cxl/ that mocks up a CXL topology to augment the nascent support for emulation of CXL devices in QEMU. - Convert libnvdimm to use the uuid API. - Complete the definition of CXL namespace labels in libnvdimm. - Tunnel libnvdimm label operations from nd_ioctl() back to the CXL mailbox driver. Enable 'ndctl {read,write}-labels' for CXL. - Continue to sort and refactor functionality into distinct driver and core-infrastructure buckets. For example, mailbox handling is now a generic core capability consumed by the PCI and cxl_test drivers" * tag 'cxl-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (34 commits) ocxl: Use pci core's DVSEC functionality cxl/pci: Use pci core's DVSEC functionality PCI: Add pci_find_dvsec_capability to find designated VSEC cxl/pci: Split cxl_pci_setup_regs() cxl/pci: Add @base to cxl_register_map cxl/pci: Make more use of cxl_register_map cxl/pci: Remove pci request/release regions cxl/pci: Fix NULL vs ERR_PTR confusion cxl/pci: Remove dev_dbg for unknown register blocks cxl/pci: Convert register block identifiers to an enum cxl/acpi: Do not fail cxl_acpi_probe() based on a missing CHBS cxl/pci: Disambiguate cxl_pci further from cxl_mem Documentation/cxl: Add bus internal docs cxl/core: Split decoder setup into alloc + add tools/testing/cxl: Introduce a mock memory device + driver cxl/mbox: Move command definitions to common location cxl/bus: Populate the target list at decoder create tools/testing/cxl: Introduce a mocked-up CXL port hierarchy cxl/pmem: Add support for multiple nvdimm-bridge objects cxl/pmem: Translate NVDIMM label commands to CXL label commands ...
2021-10-29cxl/pci: Use pci core's DVSEC functionalityBen Widawsky
Reduce maintenance burden of DVSEC query implementation by using the centralized PCI core implementation. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: kill cxl_pci_dvsec()] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163379788528.692348.11581080806976608802.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Split cxl_pci_setup_regs()Ben Widawsky
In preparation for moving parts of register mapping to cxl_core, split cxl_pci_setup_regs() into a helper that finds register blocks, (cxl_find_regblock()), and a generic wrapper that probes the precise register sets within a block (cxl_setup_regs()). Move the actual mapping (cxl_map_regs()) of the only register-set that cxl_pci cares about (memory device registers) up a level from the former cxl_pci_setup_regs() into cxl_pci_probe(). With this change the unused component registers are no longer mapped, but the helpers are primed to move into the core. [djbw: drop cxl_map_regs() for component registers] Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: rebase on the cxl_register_map refactor] Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163434053788.914258.18412599112859205220.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Add @base to cxl_register_mapDan Williams
In addition to carrying @barno, @block_offset, and @reg_type, add @base to keep all map/unmap parameters in one object. The helpers cxl_{map,unmap}_regblock() handle adjusting @base to the @block_offset at map and unmap time. Document that @base incorporates @block_offset so that downstream consumers of a mapped cxl_register_map instance do not need perform any fixups / can use @base directly. Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163433497228.889435.11271988238496181536.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Make more use of cxl_register_mapBen Widawsky
The structure exists to pass around information about register mapping. Use it for passing @barno and @block_offset, and eliminate duplicate local variables. The helpers that use @map do not care about @cxlm, so just pass them a pdev instead. [djbw: reorder before cxl_pci_setup_regs() refactor to improver readability] Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> [djbw: separate @base conversion] Link: https://lore.kernel.org/r/163416901172.806743.10056306321247850914.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Remove pci request/release regionsBen Widawsky
Quoting Dan, "... the request + release regions should probably just be dropped. It's not like any of the register enumeration would collide with someone else who already has the registers mapped. The collision only comes when the registers are mapped for their final usage, and that will have more precision in the request." Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163379785872.692348.8981679111988251260.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Fix NULL vs ERR_PTR confusionDan Williams
cxl_pci_map_regblock() may return an ERR_PTR(), but cxl_pci_setup_regs() is only prepared for NULL as the error case. Pick the minimal fix for -stable backport purposes and just have cxl_pci_map_regblock() return NULL for errors. Fixes: f8a7e8c29be8 ("cxl/pci: Reserve all device regions at once") Cc: <stable@vger.kernel.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163433325724.834522.17809774578178224149.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Remove dev_dbg for unknown register blocksBen Widawsky
While interesting to driver developers, the dev_dbg message doesn't do much except clutter up logs. This information should be attainable through sysfs, and someday lspci like utilities. This change additionally helps reduce the LOC in a subsequent patch to refactor some of cxl_pci register mapping. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163379784717.692348.3478221381958300790.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-29cxl/pci: Convert register block identifiers to an enumBen Widawsky
In preparation for passing around the Register Block Indicator (RBI) as a parameter, it is desirable to convert the type to an enum so that the interface can use a well defined parameter. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> [djbw: changelog fixups ] Link: https://lore.kernel.org/r/163379784199.692348.4366131432595112771.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-08cxl/acpi: Do not fail cxl_acpi_probe() based on a missing CHBSAlison Schofield
When an ACPI0016 Host Bridge device is present yet no corresponding CEDT Host Bridge Structure (CHBS) exists, the ACPI probe method fails. Rather than fail, emit this warning and continue: cxl_acpi ACPI0017:00: No CHBS found for Host Bridge: ACPI0016:02 This error may occur on systems that are not compliant with the ACPI specification. Compliant systems include a CHBS entry for every CXL host bridge that is present at boot. Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20211007213426.392644-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-25cxl/core: Replace unions with struct_group()Kees Cook
Use the newly introduced struct_group_typed() macro to clean up the declaration of struct cxl_regs. Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: linux-cxl@vger.kernel.org Suggested-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2021-09-21cxl/pci: Disambiguate cxl_pci further from cxl_memBen Widawsky
Commit 21e9f76733a8 ("cxl: Rename mem to pci") introduced the cxl_pci driver which had formerly been named cxl_mem. At the time, the goal was to be as light touch as possible because there were other patches in flight. Since things have settled now, and a new cxl_mem driver will be introduced shortly, spend the LOC now to clean up the existing names. While here, fix the kernel docs to explain the situation better after the core rework that has already landed. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/20210913163324.1008564-4-ben.widawsky@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/core: Split decoder setup into alloc + addDan Williams
The kbuild robot reports: drivers/cxl/core/bus.c:516:1: warning: stack frame size (1032) exceeds limit (1024) in function 'devm_cxl_add_decoder' It is also the case the devm_cxl_add_decoder() is unwieldy to use for all the different decoder types. Fix the stack usage by splitting the creation into alloc and add steps. This also allows for context specific construction before adding. With the split the caller is responsible for registering a devm callback to trigger device_unregister() for the decoder rather than it being implicit in the decoder registration. I.e. the routine that calls alloc is responsible for calling put_device() if the "add" operation fails. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Nathan Chancellor <nathan@kernel.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163225205828.3038145.6831131648369404859.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21tools/testing/cxl: Introduce a mock memory device + driverDan Williams
Introduce an emulated device-set plus driver to register CXL memory devices, 'struct cxl_memdev' instances, in the mock cxl_test topology. This enables the development of HDM Decoder (Host-managed Device Memory Decoder) programming flow (region provisioning) in an environment that can be updated alongside the kernel as it gains more functionality. Whereas the cxl_pci module looks for CXL memory expanders on the 'pci' bus, the cxl_mock_mem module attaches to CXL expanders on the platform bus emitted by cxl_test. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116440099.2460985.10692549614409346604.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Move command definitions to common locationDan Williams
In preparation for cxl_test to mock responses to mailbox command requests, move some definitions from core/mbox.c to cxlmem.h. No functional changes intended. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116439547.2460985.10457111177103589574.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/bus: Populate the target list at decoder createDan Williams
As found by cxl_test, the implementation populated the target_list for the single dport exceptional case, it missed populating the target_list for the typical multi-dport case. Root decoders always know their target list at the beginning of time, and even switch-level decoders should have a target list of one or more zeros by default, depending on the interleave-ways setting. Walk the hosting port's dport list and populate based on the passed in map. Move devm_cxl_add_passthrough_decoder() out of line now that it does the work of generating a target_map. Before: $ cat /sys/bus/cxl/devices/root2/decoder*/target_list 0 0 After: $ cat /sys/bus/cxl/devices/root2/decoder*/target_list 0 0,1,2,3 0 0,1,2,3 Where root2 is a CXL topology root object generated by 'cxl_test'. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116439000.2460985.11713777051267946018.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21tools/testing/cxl: Introduce a mocked-up CXL port hierarchyDan Williams
Create an environment for CXL plumbing unit tests. Especially when it comes to an algorithm for HDM Decoder (Host-managed Device Memory Decoder) programming, the availability of an in-kernel-tree emulation environment for CXL configuration complexity and corner cases speeds development and deters regressions. The approach taken mirrors what was done for tools/testing/nvdimm/. I.e. an external module, cxl_test.ko built out of the tools/testing/cxl/ directory, provides mock implementations of kernel APIs and kernel objects to simulate a real world device hierarchy. One feedback for the tools/testing/nvdimm/ proposal was "why not do this in QEMU?". In fact, the CXL development community has developed a QEMU model for CXL [1]. However, there are a few blocking issues that keep QEMU from being a tight fit for topology + provisioning unit tests: 1/ The QEMU community has yet to show interest in merging any of this support that has had patches on the list since November 2020. So, testing CXL to date involves building custom QEMU with out-of-tree patches. 2/ CXL mechanisms like cross-host-bridge interleave do not have a clear path to be emulated by QEMU without major infrastructure work. This is easier to achieve with the alloc_mock_res() approach taken in this patch to shortcut-define emulated system physical address ranges with interleave behavior. The QEMU enabling has been critical to get the driver off the ground, and may still move forward, but it does not address the ongoing needs of a regression testing environment and test driven development. This patch adds an ACPI CXL Platform definition with emulated CXL multi-ported host-bridges. A follow on patch adds emulated memory expander devices. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/20210202005948.241655-1-ben.widawsky@intel.com [1] Link: https://lore.kernel.org/r/163164680798.2831381.838684634806668012.stgit@dwillia2-desk3.amr.corp.intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pmem: Add support for multiple nvdimm-bridge objectsDan Williams
In preparation for a mocked unit test environment for CXL objects, allow for multiple unique nvdimm-bridge objects. For now, just allow multiple bridges to be registered. Later, when there are multiple present, further updates are needed to cxl_find_nvdimm_bridge() to identify which bridge is associated with which CXL hierarchy for nvdimm registration. Note that this does change the kernel device-name for the bridge object. User space should not have any attachment to the device name at this point as it is still early days in the CXL driver development. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163164647007.2831228.2150246954620721526.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pmem: Translate NVDIMM label commands to CXL label commandsDan Williams
The LIBNVDIMM IOCTL UAPI calls back to the nvdimm-bus-provider to translate the Linux command payload to the device native command format. The LIBNVDIMM commands get-config-size, get-config-data, and set-config-data, map to the CXL memory device commands device-identify, get-lsa, and set-lsa. Recall that the label-storage-area (LSA) on an NVDIMM device arranges for the provisioning of namespaces. Additionally for CXL the LSA is used for provisioning regions as well. The data from device-identify is already cached in the 'struct cxl_mem' instance associated with @cxl_nvd, so that payload return is simply crafted and no CXL command is issued. The conversion for get-lsa is straightforward, but the conversion for set-lsa requires an allocation to append the set-lsa header in front of the payload. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163122524923.2534512.9431316965424264864.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Add exclusive kernel command supportDan Williams
The CXL_PMEM driver expects exclusive control of the label storage area space. Similar to the LIBNVDIMM expectation that the label storage area is only writable from userspace when the corresponding memory device is not active in any region, the expectation is the native CXL_PCI UAPI path is disabled while the cxl_nvdimm for a given cxl_memdev device is active in LIBNVDIMM. Add the ability to toggle the availability of a given command for the UAPI path. Use that new capability to shutdown changes to partitions and the label storage area while the cxl_nvdimm device is actively proxying commands for LIBNVDIMM. Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163164579468.2830966.6980053377428474263.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Convert 'enabled_cmds' to DECLARE_BITMAPDan Williams
Define enabled_cmds as an embedded member of 'struct cxl_mem' rather than a pointer to another dynamic allocation. As this leaves only one user of cxl_cmd_count, just open code it and delete the helper. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116436415.2460985.10101824045493194813.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pci: Use module_pci_driverDan Williams
Now that cxl_mem_{init,exit} no longer need to manage debugfs, switch back to the smaller form of the boiler plate. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116435825.2460985.7201322215431441130.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Move mailbox and other non-PCI specific infrastructure to the coreDan Williams
Now that the internals of mailbox operations are abstracted from the PCI specifics a bulk of infrastructure can move to the core. The CXL_PMEM driver intends to proxy LIBNVDIMM UAPI and driver requests to the equivalent functionality provided by the CXL hardware mailbox interface. In support of that intent move the mailbox implementation to a shared location for the CXL_PCI driver native IOCTL path and CXL_PMEM nvdimm command proxy path to share. A unit test framework seeks to implement a unit test backend transport for mailbox commands to communicate mocked up payloads. It can reuse all of the mailbox infrastructure minus the PCI specifics, so that also gets moved to the core. Finally with the mailbox infrastructure and ioctl handling being transport generic there is no longer any need to pass file file_operations to devm_cxl_add_memdev(). That allows all the ioctl boilerplate to move into the core for unit test reuse. No functional change intended, just code movement. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163116435233.2460985.16197340449713287180.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pci: Drop idr.hDan Williams
Commit 3d135db51024 ("cxl/core: Move memdev management to core") left this straggling include for cxl_memdev setup. Clean it up. Cc: Ben Widawsky <ben.widawsky@intel.com> Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163116434668.2460985.12264757586266849616.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/mbox: Introduce the mbox_send operationDan Williams
In preparation for implementing a unit test backend transport for ioctl operations, and making the mailbox available to the cxl/pmem infrastructure, move the existing PCI specific portion of mailbox handling to an "mbox_send" operation. With this split all the PCI-specific transport details are comprehended by a single operation and the rest of the mailbox infrastructure is 'struct cxl_mem' and 'struct cxl_memdev' generic. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163116434098.2460985.9004760022659400540.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pci: Clean up cxl_mem_get_partition_info()Dan Williams
Commit 0b9159d0ff21 ("cxl/pci: Store memory capacity values") missed updating the kernel-doc for 'struct cxl_mem' leading to the following warnings: ./scripts/kernel-doc -v drivers/cxl/cxlmem.h 2>&1 | grep warn drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'total_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'volatile_only_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'persistent_only_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'partition_align_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'active_volatile_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'active_persistent_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'next_volatile_bytes' not described in 'cxl_mem' drivers/cxl/cxlmem.h:107: warning: Function parameter or member 'next_persistent_bytes' not described in 'cxl_mem' Also, it is redundant to describe those same parameters in the kernel-doc for cxl_mem_get_partition_info(). Given the only user of that routine updates the values in @cxlm, just do that implicitly internal to the helper. Cc: Ira Weiny <ira.weiny@intel.com> Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163157174216.2653013.1277706528753990974.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-21cxl/pci: Make 'struct cxl_mem' device type genericDan Williams
In preparation for adding a unit test provider of a cxl_memdev, convert the 'struct cxl_mem' driver context to carry a generic device rather than a pci device. Note, some dev_dbg() lines needed extra reformatting per clang-format. This conversion also allows the cxl_mem_create() and devm_cxl_add_memdev() calling conventions to be simplified. The "host" for a cxl_memdev, must be the same device for the driver that allocated @cxlm. Acked-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/163116432973.2460985.7553504957932024222.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-09Merge tag 'cxl-for-5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull CXL (Compute Express Link) updates from Dan Williams: - Fix detection of CXL host bridges to filter out disabled ACPI0016 devices in the ACPI DSDT. - Fix kernel lockdown integration to disable raw commands when raw PCI access is disabled. - Fix a broken debug message. - Add support for "Get Partition Info". I.e. enumerate the split between volatile and persistent capacity on bi-modal CXL memory expanders. - Re-factor the core by subject area. This is a work in progress. - Prepare libnvdimm to understand CXL labels in addition to EFI labels. This is a work in progress. * tag 'cxl-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (25 commits) cxl/registers: Fix Documentation warning cxl/pmem: Fix Documentation warning cxl/uapi: Fix defined but not used warnings cxl/pci: Fix debug message in cxl_probe_regs() cxl/pci: Fix lockdown level cxl/acpi: Do not add DSDT disabled ACPI0016 host bridge ports libnvdimm/labels: Add claim class helpers libnvdimm/labels: Add type-guid helpers libnvdimm/labels: Add blk special cases for nlabel and position helpers libnvdimm/labels: Add blk isetcookie set / validation helpers libnvdimm/labels: Add a checksum calculation helper libnvdimm/labels: Introduce label setter helpers libnvdimm/labels: Add isetcookie validation helper libnvdimm/labels: Introduce getters for namespace label fields cxl/mem: Adjust ram/pmem range to represent DPA ranges cxl/mem: Account for partitionable space in ram/pmem ranges cxl/pci: Store memory capacity values cxl/pci: Simplify register setup cxl/pci: Ignore unknown register block types cxl/core: Move memdev management to core ...
2021-09-07cxl/registers: Fix Documentation warningDan Williams
Commit 0f06157e0135 ("cxl/core: Move register mapping infrastructure") neglected to add a DOC header for the new drivers/core/regs.c file. Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163072206675.2250120.3527179192933919995.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-07cxl/pmem: Fix Documentation warningDan Williams
Commit 06737cd0d216 ("cxl/core: Move pmem functionality") neglected to add a DOC header for the new drivers/cxl/core/pmem.c file. Reported-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huwei.com> Link: https://lore.kernel.org/r/163072206163.2250120.11486436976516079516.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-07cxl/pci: Fix debug message in cxl_probe_regs()Li Qiang (Johnny Li)
Indicator string for mbox and memdev register set to status incorrectly in error message. Cc: <stable@vger.kernel.org> Fixes: 30af97296f48 ("cxl/pci: Map registers based on capabilities") Signed-off-by: Li Qiang (Johnny Li) <johnny.li@montage-tech.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163072205089.2250120.8103605864156687395.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-07cxl/pci: Fix lockdown levelDan Williams
A proposed rework of security_locked_down() users identified that the cxl_pci driver was passing the wrong lockdown_reason. Update cxl_mem_raw_command_allowed() to fail raw command access when raw pci access is also disabled. Fixes: 13237183c735 ("cxl/mem: Add a "RAW" send command") Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: <stable@vger.kernel.org> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/163072204525.2250120.16615792476976546735.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-09-07cxl/acpi: Do not add DSDT disabled ACPI0016 host bridge portsAlison Schofield
During CXL ACPI probe, host bridge ports are discovered by scanning the ACPI0017 root port for ACPI0016 host bridge devices. The scan matches on the hardware id of "ACPI0016". An issue occurs when an ACPI0016 device is defined in the DSDT yet disabled on the platform. Attempts by the cxl_acpi driver to add host bridge ports using a disabled device fails, and the entire cxl_acpi probe fails. The DSDT table includes an _STA method that sets the status and the ACPI subsystem has checks available to examine it. One such check is in the acpi_pci_find_root() path. Move the call to acpi_pci_find_root() to the matching function to prevent this issue when adding either upstream or downstream ports. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Fixes: 7d4b5ca2e2cb ("cxl/acpi: Add downstream port data to cxl_port instances") Cc: <stable@vger.kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/163072203957.2250120.2178685721061002124.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-10cxl/mem: Adjust ram/pmem range to represent DPA rangesIra Weiny
CXL spec defines the volatile DPA range to be 0 to Volatile memory size. It further defines the persistent DPA range to follow directly after the end of the Volatile DPA through the persistent memory size. Essentially Volatile DPA range = [0, Volatile size) Persistent DPA range = [Volatile size, Volatile size + Persistent size) Adjust the pmem_range start to reflect this and remote the TODO. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20210617221620.1904031-4-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-10cxl/mem: Account for partitionable space in ram/pmem rangesIra Weiny
Memory devices may specify volatile only, persistent only, and partitionable space which when added together result in a total capacity. If Identify Memory Device.Partition Alignment != 0 the device supports partitionable space. This partitionable space can be split between volatile and persistent space. The total volatile and persistent sizes are reported in Get Partition Info. ie active volatile memory = volatile only + partitionable volatile active persistent memory = persistent only + partitionable persistent Define cxl_mem_get_partition(), check for partitionable support, and use cxl_mem_get_partition() if applicable. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-07cxl/pci: Store memory capacity valuesIra Weiny
The Identify Memory Device command returns information about the volatile only and persistent only memory capacities. Store those values in the cxl_mem structure for later use. While at it, reuse those calculations to calculate the ram and pmem ranges. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20210617221620.1904031-2-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-06cxl/pci: Simplify register setupBen Widawsky
It is desirable to retain the mappings from the calling function. By simplifying this code, it will be much more straightforward to do that. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20210716231548.174778-3-ben.widawsky@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-06cxl/pci: Ignore unknown register block typesBen Widawsky
In an effort to explicit avoid supporting vendor specific register blocks (which can happily be mapped from userspace), entirely skip probing unknown types. The secondary benefit of this will be revealed in the future with code simplification. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20210716231548.174778-2-ben.widawsky@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-06cxl/core: Move memdev management to coreBen Widawsky
The motivation for moving cxl_memdev allocation to the core (beyond better file organization of sysfs attributes in core/ and drivers in cxl/), is that device lifetime is longer than module lifetime. The cxl_pci module should be free to come and go without needing to coordinate with devices that need the text associated with cxl_memdev_release() to stay resident. The move fixes a use after free bug when looping driver load / unload with CONFIG_DEBUG_KOBJECT_RELEASE=y. Another motivation for disconnecting cxl_memdev creation from cxl_pci is to enable other drivers, like a unit test driver, to registers memdevs. Fixes: b39cb1052a5c ("cxl/mem: Register CXL memX devices") Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/162792540495.368511.9748638751088219595.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-08-06cxl/pci: Introduce cdevm_file_operationsDan Williams
In preparation for moving cxl_memdev allocation to the core, introduce cdevm_file_operations to coordinate file operations shutdown relative to driver data release. The motivation for moving cxl_memdev allocation to the core (beyond better file organization of sysfs attributes in core/ and drivers in cxl/), is that device lifetime is longer than module lifetime. The cxl_pci module should be free to come and go without needing to coordinate with devices that need the text associated with cxl_memdev_release() to stay resident. The move will fix a use after free bug when looping driver load / unload with CONFIG_DEBUG_KOBJECT_RELEASE=y. Another motivation for passing in file_operations to the core cxl_memdev creation flow is to allow for alternate drivers, like unit test code, to define their own ioctl backends. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/162792539962.368511.2962268954245340288.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>