lwn.git/drivers/cxl, branch docs-6.4-2

Merge tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2023-02-25T17:19:23+00:00

Pull Compute Express Link (CXL) updates from Dan Williams: "To date Linux has been dependent on platform-firmware to map CXL RAM regions and handle events / errors from devices. With this update we can now parse / update the CXL memory layout, and report events / errors from devices. This is a precursor for the CXL subsystem to handle the end-to-end "RAS" flow for CXL memory. i.e. the flow that for DDR-attached-DRAM is handled by the EDAC driver where it maps system physical address events to a field-replaceable-unit (FRU / endpoint device). In general, CXL has the potential to standardize what has historically been a pile of memory-controller-specific error handling logic. Another change of note is the default policy for handling RAM-backed device-dax instances. Previously the default access mode was "device", mmap(2) a device special file to access memory. The new default is "kmem" where the address range is assigned to the core-mm via add_memory_driver_managed(). This saves typical users from wondering why their platform memory is not visible via free(1) and stuck behind a device-file. At the same time it allows expert users to deploy policy to, for example, get dedicated access to high performance memory, or hide low performance memory from general purpose kernel allocations. This affects not only CXL, but also systems with high-bandwidth-memory that platform-firmware tags with the EFI_MEMORY_SP (special purpose) designation. Summary: - CXL RAM region enumeration: instantiate 'struct cxl_region' objects for platform firmware created memory regions - CXL RAM region provisioning: complement the existing PMEM region creation support with RAM region support - "Soft Reservation" policy change: Online (memory hot-add) soft-reserved memory (EFI_MEMORY_SP) by default, but still allow for setting aside such memory for dedicated access via device-dax. - CXL Events and Interrupts: Takeover CXL event handling from platform-firmware (ACPI calls this CXL Memory Error Reporting) and export CXL Events via Linux Trace Events. - Convey CXL _OSC results to drivers: Similar to PCI, let the CXL subsystem interrogate the result of CXL _OSC negotiation. - Emulate CXL DVSEC Range Registers as "decoders": Allow for first-generation devices that pre-date the definition of the CXL HDM Decoder Capability to translate the CXL DVSEC Range Registers into 'struct cxl_decoder' objects. - Set timestamp: Per spec, set the device timestamp in case of hotplug, or if platform-firwmare failed to set it. - General fixups: linux-next build issues, non-urgent fixes for pre-production hardware, unit test fixes, spelling and debug message improvements" * tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (66 commits) dax/kmem: Fix leak of memory-hotplug resources cxl/mem: Add kdoc param for event log driver state cxl/trace: Add serial number to trace points cxl/trace: Add host output to trace points cxl/trace: Standardize device information output cxl/pci: Remove locked check for dvsec_range_allowed() cxl/hdm: Add emulation when HDM decoders are not committed cxl/hdm: Create emulated cxl_hdm for devices that do not have HDM decoders cxl/hdm: Emulate HDM decoder from DVSEC range registers cxl/pci: Refactor cxl_hdm_decode_init() cxl/port: Export cxl_dvsec_rr_decode() to cxl_port cxl/pci: Break out range register decoding from cxl_hdm_decode_init() cxl: add RAS status unmasking for CXL cxl: remove unnecessary calling of pci_enable_pcie_error_reporting() dax/hmem: build hmem device support as module if possible dax: cxl: add CXL_REGION dependency cxl: avoid returning uninitialized error code cxl/pmem: Fix nvdimm registration races cxl/mem: Fix UAPI command comment cxl/uapi: Tag commands from cxl_query_cmd() ...

Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2023-02-24T20:58:55+00:00

Pull driver core updates from Greg KH: "Here is the large set of driver core changes for 6.3-rc1. There's a lot of changes this development cycle, most of the work falls into two different categories: - fw_devlink fixes and updates. This has gone through numerous review cycles and lots of review and testing by lots of different devices. Hopefully all should be good now, and Saravana will be keeping a watch for any potential regression on odd embedded systems. - driver core changes to work to make struct bus_type able to be moved into read-only memory (i.e. const) The recent work with Rust has pointed out a number of areas in the driver core where we are passing around and working with structures that really do not have to be dynamic at all, and they should be able to be read-only making things safer overall. This is the contuation of that work (started last release with kobject changes) in moving struct bus_type to be constant. We didn't quite make it for this release, but the remaining patches will be finished up for the release after this one, but the groundwork has been laid for this effort. Other than that we have in here: - debugfs memory leak fixes in some subsystems - error path cleanups and fixes for some never-able-to-be-hit codepaths. - cacheinfo rework and fixes - Other tiny fixes, full details are in the shortlog All of these have been in linux-next for a while with no reported problems" [ Geert Uytterhoeven points out that that last sentence isn't true, and that there's a pending report that has a fix that is queued up - Linus ] * tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits) debugfs: drop inline constant formatting for ERR_PTR(-ERROR) OPP: fix error checking in opp_migrate_dentry() debugfs: update comment of debugfs_rename() i3c: fix device.h kernel-doc warnings dma-mapping: no need to pass a bus_type into get_arch_dma_ops() driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place Revert "driver core: add error handling for devtmpfs_create_node()" Revert "devtmpfs: add debug info to handle()" Revert "devtmpfs: remove return value of devtmpfs_delete_node()" driver core: cpu: don't hand-override the uevent bus_type callback. devtmpfs: remove return value of devtmpfs_delete_node() devtmpfs: add debug info to handle() driver core: add error handling for devtmpfs_create_node() driver core: bus: update my copyright notice driver core: bus: add bus_get_dev_root() function driver core: bus: constify bus_unregister() driver core: bus: constify some internal functions driver core: bus: constify bus_get_kset() driver core: bus: constify bus_register/unregister_notifier() driver core: remove private pointer from struct bus_type ...

Merge branch 'for-6.3/cxl-events' into cxl/next

2023-02-16T23:27:12+00:00

Include some additional fixups for event support for v6.3, namely, rationalize the identifiers in the trace output and fixup a kdoc comment.

cxl/mem: Add kdoc param for event log driver state

2023-02-16T22:50:03+00:00

This makes the kernel-doc for cxl_dev_state complete. Signed-off-by: Alison Schofield Link: https://lore.kernel.org/r/20230216192426.1184606-1-alison.schofield@intel.com Signed-off-by: Dan Williams

cxl/trace: Add serial number to trace points

2023-02-16T22:29:11+00:00

Device serial numbers are useful information for the user. Add device serial numbers to all the trace points. Cc: Steven Rostedt Cc: Dave Jiang Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20230208-cxl-event-names-v2-3-fca130c2c68b@intel.com Signed-off-by: Dan Williams

cxl/trace: Add host output to trace points

2023-02-16T22:29:11+00:00

The host parameter of where the memdev is connected is useful information. Report host consistently in all trace points. Cc: Steven Rostedt Cc: Dave Jiang Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20230208-cxl-event-names-v2-2-fca130c2c68b@intel.com Signed-off-by: Dan Williams

cxl/trace: Standardize device information output

2023-02-16T22:29:11+00:00

The trace points were written to take a struct device input for the trace. In CXL multiple device objects are associated with each CXL hardware device. Using different device objects in the trace point can lead to confusion for users. The PCIe device is nice to have, but the user space tooling relies on the memory device naming. It is better to have those device names reported. Change all trace points to take struct cxl_memdev as a standard and report that name. Furthermore, standardize on the name 'memdev' in both /sys/kernel/tracing/trace and cxl-cli monitor output. Cc: Steven Rostedt Cc: Dave Jiang Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20230208-cxl-event-names-v2-1-fca130c2c68b@intel.com Signed-off-by: Dan Williams

Merge branch 'for-6.3/cxl-rr-emu' into cxl/next

2023-02-15T00:06:10+00:00

Pick up the CXL DVSEC range register emulation for v6.3, and resolve conflicts with the cxl_port_probe() split (from for-6.3/cxl-ram-region) and event handling (from for-6.3/cxl-events).

cxl/pci: Remove locked check for dvsec_range_allowed()

2023-02-14T23:45:21+00:00

Remove the CXL_DECODER_F_LOCK check to be permissive of platform BIOSes that allow CXL.mem to be remapped. Reviewed-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/167640370085.935665.13128321011001358077.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams

cxl/hdm: Add emulation when HDM decoders are not committed

2023-02-14T23:45:21+00:00

For the case where DVSEC range register(s) are active and HDM decoders are not committed, use RR to provide emulation. A first pass is done to note whether any decoders are committed. If there are no committed endpoint decoders, then DVSEC ranges will be used for emulation. Reviewed-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/167640369536.935665.611974113442400127.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams