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path: root/drivers/cxl/cxl.h
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2024-03-12cxl: Split out combine_coordinates() for common shared usageDave Jiang
Refactor the common code of combining coordinates in order to reduce code. Create a new function cxl_cooordinates_combine() it combine two 'struct access_coordinate'. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240308220055.2172956-6-dave.jiang@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-03-12ACPI: HMAT / cxl: Add retrieval of generic port coordinates for both access ↵Dave Jiang
classes Update acpi_get_genport_coordinates() to allow retrieval of both access classes of the 'struct access_coordinate' for a generic target. The update will allow CXL code to compute access coordinates for both access class. Cc: Rafael J. Wysocki <rafael@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240308220055.2172956-5-dave.jiang@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-02-16cxl: Fix sysfs export of qos_class for memdevDave Jiang
Current implementation exports only to /sys/bus/cxl/devices/.../memN/qos_class. With both ram and pmem exposed, the second registered sysfs attribute is rejected as duplicate. It's not possible to create qos_class under the dev_groups via the driver due to the ram and pmem sysfs sub-directories already created by the device sysfs groups. Move the ram and pmem qos_class to the device sysfs groups and add a call to sysfs_update() after the perf data are validated so the qos_class can be visible. The end results should be /sys/bus/cxl/devices/.../memN/ram/qos_class and /sys/bus/cxl/devices/.../memN/pmem/qos_class. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20240206190431.1810289-4-dave.jiang@intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-05Merge branch 'for-6.7/cxl' into for-6.8/cxlDan Williams
Pick up a late locking change + fixup that is better as merge window material than rc material.
2024-01-05cxl: Convert find_cxl_root() to return a 'struct cxl_root *'Dave Jiang
Commit 790815902ec6 ("cxl: Add support for _DSM Function for retrieving QTG ID") introduced 'struct cxl_root', however all usages have been worked indirectly through cxl_port. Refactor code such as find_cxl_root() function to use 'struct cxl_root' directly. Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170449246044.3779673.13035770941393418591.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-05cxl: Introduce put_cxl_root() helperDave Jiang
Add a helper function put_cxl_root() to maintain symmetry for find_cxl_root() function instead of relying on open coding of the put_device() in order to dereference the 'struct device' that happens via get_device() in find_cxl_root(). Suggested-by: Robert Richter <rrichter@amd.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/170449245417.3779673.4566146351673989387.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-04cxl/port: Fix missing target list lockDan Williams
cxl_port_setup_targets() modifies the ->targets[] array of a switch decoder. target_list_show() expects to be able to emit a coherent snapshot of that array by "holding" ->target_lock for read. The target_lock is held for write during initialization of the ->targets[] array, but it is not held for write during cxl_port_setup_targets(). The ->target_lock() predates the introduction of @cxl_region_rwsem. That semaphore protects changes to host-physical-address (HPA) decode which is precisely what writes to a switch decoder's target list affects. Replace ->target_lock with @cxl_region_rwsem. Now the side-effect of snapshotting a unstable view of a decoder's target list is likely benign so the Fixes: tag is presumptive. Fixes: 27b3f8d13830 ("cxl/region: Program target lists") Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Add helper function that calculate performance data for downstream portsDave Jiang
The CDAT information from the switch, Switch Scoped Latency and Bandwidth Information Structure (SSLBIS), is parsed and stored under a cxl_dport based on the correlated downstream port id from the SSLBIS entry. Walk the entire CXL port paths and collect all the performance data. Also pick up the link latency number that's stored under the dports. The entire path PCIe bandwidth can be retrieved using the pcie_bandwidth_available() call. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319623824.2212653.10302079766473698427.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Store the access coordinates for the generic portsDave Jiang
Each CXL host bridge is represented by an ACPI0016 device. A generic port device handle that is an ACPI device is represented by a string of ACPI0016 device HID and UID. Create a device handle from the ACPI device and retrieve the access coordinates from the stored memory targets. The access coordinates are stored under the cxl_dport that is associated with the CXL host bridge. The access coordinates struct is dynamically allocated under cxl_dport in order for code later on to detect whether the data exists or not. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319623196.2212653.17916695743464172534.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Calculate and store PCI link latency for the downstream portsDave Jiang
The latency is calculated by dividing the flit size over the bandwidth. Add support to retrieve the flit size for the CXL switch device and calculate the latency of the PCIe link. Cache the latency number with cxl_dport. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319621931.2212653.6800240203604822886.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Add support for _DSM Function for retrieving QTG IDDave Jiang
CXL spec v3.0 9.17.3 CXL Root Device Specific Methods (_DSM) Add support to retrieve QTG ID via ACPI _DSM call. The _DSM call requires an input of an ACPI package with 4 dwords (read latency, write latency, read bandwidth, write bandwidth). The call returns a package with 1 WORD that provides the max supported QTG ID and a package that may contain 0 or more WORDs as the recommended QTG IDs in the recommended order. Create a cxl_root container for the root cxl_port and provide a callback ->get_qos_class() in order to retrieve the QoS class. For the ACPI case, the _DSM helper is used to retrieve the QTG ID and returned. A devm_cxl_add_root() function is added for root port setup and registration of the cxl_root callback operation(s). Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/170319621294.2212653.1649682083061569256.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Add callback to parse the SSLBIS subtable from CDATDave Jiang
Provide a callback to parse the Switched Scoped Latency and Bandwidth Information Structure (SSLBIS) in the CDAT structures. The SSLBIS contains the bandwidth and latency information that's tied to the CXL switch that the data table has been read from. The extracted values are stored to the cxl_dport correlated by the port_id depending on the SSLBIS entry. Coherent Device Attribute Table 1.03 2.1 Switched Scoped Latency and Bandwidth Information Structure (DSLBIS) Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319620635.2212653.5194389158785365150.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Add callback to parse the DSMAS subtables from CDATDave Jiang
Provide a callback function to the CDAT parser in order to parse the Device Scoped Memory Affinity Structure (DSMAS). Each DSMAS structure contains the DPA range and its associated attributes in each entry. See the CDAT specification for details. The device handle and the DPA range is saved and to be associated with the DSLBIS locality data when the DSLBIS entries are parsed. The xarray is a local variable. When the total path performance data is calculated and storred this xarray can be discarded. Coherent Device Attribute Table 1.03 2.1 Device Scoped memory Affinity Structure (DSMAS) Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319619355.2212653.2675953129671561293.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-31Merge branch 'for-6.7/cxl-commited' into cxl/nextDan Williams
Add the committed decoder sysfs attribute for v6.7.
2023-10-31Merge branch 'for-6.7/cxl-qtg' into cxl/nextDan Williams
Merge some prep-work for CXL QOS class support. This cycle saw large collisions with mm on this topic, so the bulk of this topic needs to wait.
2023-10-27cxl: Export QTG ids from CFMWS to sysfs as qos_class attributeDave Jiang
Export the QoS Throttling Group ID from the CXL Fixed Memory Window Structure (CFMWS) under the root decoder sysfs attributes as qos_class. CXL rev3.0 9.17.1.3 CXL Fixed Memory Window Structure (CFMWS) cxl cli will use this id to match with the _DSM retrieved id for a hot-plugged CXL memory device DPA memory range to make sure that the DPA range is under the right CFMWS window. Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/169713681699.2205276.14475306324720093079.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl: Add cxl_decoders_committed() helperDave Jiang
Add a helper to retrieve the number of decoders committed for the port. Replace all the open coding of the calculation with the helper. Link: https://lore.kernel.org/linux-cxl/651c98472dfed_ae7e729495@dwillia2-xfh.jf.intel.com.notmuch/ Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jim Harris <jim.harris@samsung.com> Reviewed-by: Alison Schofield <alison.schofield@intel.com> Link: https://lore.kernel.org/r/169747906849.272156.1729290904857372335.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/core/regs: Rework cxl_map_pmu_regs() to use map->dev for devmRobert Richter
struct cxl_register_map carries a @dev parameter for devm operations. Simplify the function interface to use that instead of a separate @dev argument. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20231018171713.1883517-21-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/pci: Map RCH downstream AER registers for logging protocol errorsTerry Bowman
The restricted CXL host (RCH) error handler will log protocol errors using AER and RAS status registers. The AER and RAS registers need to be virtually memory mapped before enabling interrupts. Create the initializer function devm_cxl_setup_parent_dport() for this when the endpoint is connected with the dport. The initialization sets up the RCH RAS and AER mappings. Add 'struct cxl_regs' to 'struct cxl_dport' for saving a pointer to the RCH downstream port's AER and RAS registers. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20231018171713.1883517-15-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/pci: Add RCH downstream port AER register discoveryRobert Richter
Restricted CXL host (RCH) downstream port AER information is not currently logged while in the error state. One problem preventing the error logging is the AER and RAS registers are not accessible. The CXL driver requires changes to find RCH downstream port AER and RAS registers for purpose of error logging. RCH downstream ports are not enumerated during a PCI bus scan and are instead discovered using system firmware, ACPI in this case.[1] The downstream port is implemented as a Root Complex Register Block (RCRB). The RCRB is a 4k memory block containing PCIe registers based on the PCIe root port.[2] The RCRB includes AER extended capability registers used for reporting errors. Note, the RCH's AER Capability is located in the RCRB memory space instead of PCI configuration space, thus its register access is different. Existing kernel PCIe AER functions can not be used to manage the downstream port AER capabilities and RAS registers because the port was not enumerated during PCI scan and the registers are not PCI config accessible. Discover RCH downstream port AER extended capability registers. Use MMIO accesses to search for extended AER capability in RCRB register space. [1] CXL 3.0 Spec, 9.11.2 - System Firmware View of CXL 1.1 Hierarchy [2] CXL 3.0 Spec, 8.2.1.1 - RCH Downstream Port RCRB Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-12-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/port: Remove Component Register base address from struct cxl_portRobert Richter
The Component Register base address @component_reg_phys is no longer used after the rework of the Component Register setup which now uses struct member @reg_map instead. Remove the base address. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231018171713.1883517-10-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/port: Rename @comp_map to @reg_map in struct cxl_register_mapRobert Richter
Name the field @reg_map, because @reg_map->host will be used for mapping operations beyond component registers (i.e. AER registers). This is valid for all occurrences of @comp_map. Change them all. Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20231018171713.1883517-5-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27cxl/core/regs: Rename @dev to @host in struct cxl_register_mapRobert Richter
The primary role of @dev is to host the mappings for devm operations. @dev is too ambiguous as a name. I.e. when does @dev refer to the 'struct device *' instance that the registers belong, and when does @dev refer to the 'struct device *' instance hosting the mapping for devm operations? Clarify the role of @dev in cxl_register_map by renaming it to @host. Also, rename local variables to 'host' where map->host is used. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20231018171713.1883517-3-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxlDan Williams
Pick up the first half of the RCH error handling series. The back half needs some fixups for test regressions. Small conflicts with the PMU work around register enumeration and setup helpers.
2023-06-25Merge branch 'for-6.5/cxl-perf' into for-6.5/cxlDan Williams
Pick up initial support for the CXL 3.0 performance monitoring definition. Small conflicts with the firmware update work as they both placed their init code in the same location.
2023-06-25Merge branch 'for-6.5/cxl-region-fixes' into for-6.5/cxlDan Williams
Pick up the recent fixes to how CPU caches are managed relative to region setup / teardown, and make sure that all decoders transition successfully before updating the region state from COMMIT => ACTIVE.
2023-06-25Merge branch 'for-6.5/cxl-type-2' into for-6.5/cxlDan Williams
Pick up the driver cleanups identified in preparation for CXL "type-2" (accelerator) device support. The major change here from a conflict generation perspective is the split of 'struct cxl_memdev_state' from the core 'struct cxl_dev_state'. Since an accelerator may not care about all the optional features that are standard on a CXL "type-3" (host-only memory expander) device. A silent conflict also occurs with the move of the endpoint port to be a formal property of a 'struct cxl_memdev' rather than drvdata.
2023-06-25Revert "cxl/port: Enable the HDM decoder capability for switch ports"Dan Williams
commit eb0764b822b9 ("cxl/port: Enable the HDM decoder capability for switch ports") ...was added on the observation of CXL memory not being accessible after setting up a region on a "cold-plugged" device. A "cold-plugged" CXL device is one that was not present at boot, so platform-firmware/BIOS has no chance to set it up. While it is true that the debug found the enable bit clear in the host-bridge's instance of the global control register (CXL 3.0 8.2.4.19.2 CXL HDM Decoder Global Control Register), that bit is described as: "This bit is only applicable to CXL.mem devices and shall return 0 on CXL Host Bridges and Upstream Switch Ports." So it is meant to be zero, and further testing confirmed that this "fix" had no effect on the failure. Revert it, and be more vigilant about proposed fixes in the future. Since the original copied stable@, flag this revert for stable@ as well. Cc: <stable@vger.kernel.org> Fixes: eb0764b822b9 ("cxl/port: Enable the HDM decoder capability for switch ports") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168685882012.3475336.16733084892658264991.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/hdm: Default CXL_DEVTYPE_DEVMEM decoders to CXL_DECODER_DEVMEMDan Williams
In preparation for device-memory region creation, arrange for decoders of CXL_DEVTYPE_DEVMEM memdevs to default to CXL_DECODER_DEVMEM for their target type. Revisit this if a device ever shows up that wants to offer mixed HDM-H (Host-Only Memory) and HDM-DB support, or an CXL_DEVTYPE_DEVMEM device that supports HDM-H. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679261945.3436160.11673393474107374595.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Rename CXL_DECODER_{EXPANDER, ACCELERATOR} => {HOSTONLYMEM, DEVMEM}Dan Williams
In preparation for support for HDM-D and HDM-DB configuration (device-memory, and device-memory with back-invalidate). Rename the current type designators to use HOSTONLYMEM and DEVMEM as a suffix. HDM-DB can be supported by devices that are not accelerators, so DEVMEM is a more generic term for that case. Fixup one location where this type value was open coded. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679261369.3436160.7042443847605280593.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/regs: Clarify when a 'struct cxl_register_map' is input vs outputDan Williams
The @map parameter to cxl_probe_X_registers() is filled in with the mapping parameters of the register block. The @map parameter to cxl_map_X_registers() only reads that information to perform the mapping. Mark @map const for cxl_map_X_registers() to clarify that it is only an input to those helpers. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168679258103.3436160.4941603739448763855.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/region: Flag partially torn down regions as unusableDan Williams
cxl_region_decode_reset() walks all the decoders associated with a given region and disables them. Due to decoder ordering rules it is possible that a switch in the topology notices that a given decoder can not be shutdown before another region with a higher HPA is shutdown first. That can leave the region in a partially committed state. Capture that state in a new CXL_REGION_F_NEEDS_RESET flag and require that a successful cxl_region_decode_reset() attempt must be completed before cxl_region_probe() accepts the region. This is a corollary for the bug that Jonathan identified in "CXL/region : commit reset of out of order region appears to succeed." [1]. Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Link: http://lore.kernel.org/r/20230316171441.0000205b@Huawei.com [1] Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168696507423.3590522.16254212607926684429.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/region: Move cache invalidation before region teardown, and before setupDan Williams
Vikram raised a concern with the theoretical case of a CPU sending MemClnEvict to a device that is not prepared to receive. MemClnEvict is a message that is sent after a CPU has taken ownership of a cacheline from accelerator memory (HDM-DB). In the case of hotplug or HDM decoder reconfiguration it is possible that the CPU is holding old contents for a new device that has taken over the physical address range being cached by the CPU. To avoid this scenario, invalidate caches prior to tearing down an HDM decoder configuration. Now, this poses another problem that it is possible for something to speculate into that space while the decode configuration is still up, so to close that gap also invalidate prior to establish new contents behind a given physical address range. With this change the cache invalidation is now explicit and need not be checked in cxl_region_probe(), and that obviates the need for CXL_REGION_F_INCOHERENT. Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Fixes: d18bc74aced6 ("cxl/region: Manage CPU caches relative to DPA invalidation events") Reported-by: Vikram Sethi <vsethi@nvidia.com> Closes: http://lore.kernel.org/r/BYAPR12MB33364B5EB908BF7239BB996BBD53A@BYAPR12MB3336.namprd12.prod.outlook.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168696506886.3590522.4597053660991916591.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Store the downstream port's Component Register mappings in struct ↵Robert Richter
cxl_dport Same as for ports, also store the downstream port's Component Register mappings, use struct cxl_dport for that. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-16-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Store the port's Component Register mappings in struct cxl_portRobert Richter
CXL capabilities are stored in the Component Registers. To use them, the specific I/O ranges of the capabilities must be determined by probing the registers. For this, the whole Component Register range needs to be mapped temporarily to detect the offset and length of a capability range. In order to use more than one capability of a component (e.g. RAS and HDM) the Component Register are probed and its mappings created multiple times. This also causes overlapping I/O ranges as the whole Component Register range must be mapped again while a capability's I/O range is already mapped. Different capabilities cannot be setup at the same time. E.g. the RAS capability must be made available as soon as the PCI driver is bound, the HDM decoder is setup later during port enumeration. Moreover, during early setup it is still unknown if a certain capability is needed. A central capability setup is therefore not possible, capabilities must be individually enabled once needed during initialization. To avoid a duplicate register probe and overlapping I/O mappings, only probe the Component Registers one time and store the Component Register mapping in struct port. The stored mappings can be used later to iomap the capability register range when enabling the capability, which will be implemented in a follow-on patch. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-15-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/pci: Early setup RCH dport component registers from RCRBRobert Richter
CXL RAS capabilities must be enabled and accessible as soon as the CXL endpoint is detected in the PCI hierarchy and bound to the cxl_pci driver. This needs to be independent of other modules such as cxl_port or cxl_mem. CXL RAS capabilities reside in the Component Registers. For an RCH this is determined by probing RCRB which is implemented very late once the CXL Memory Device is created. Change this by moving the RCRB probe to the cxl_pci driver. Do this by using a new introduced function cxl_pci_find_port() similar to cxl_mem_find_port() to determine the involved dport by the endpoint's PCI handle. Plug this into the existing cxl_pci_setup_regs() function to setup Component Registers. Probe the RCRB in case the Component Registers cannot be located through the CXL Register Locator capability. This unifies code and early sets up the Component Registers at the same time for both, VH and RCH mode. Only the cxl_pci driver is involved for this. This allows an early mapping of the CXL RAS capability registers. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-14-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/port: Remove Component Register base address from struct cxl_dportRobert Richter
The Component Register base address @component_reg_phys is no longer used after the rework of the Component Register setup which now uses struct member @comp_map instead. Remove the base address. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-11-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/pci: Refactor component register discovery for reuseTerry Bowman
The endpoint implements component register setup code. Refactor it for reuse with RCRB, downstream port, and upstream port setup. Move PCI specifics from cxl_setup_regs() into cxl_pci_setup_regs(). Move cxl_setup_regs() into cxl/core/regs.c and export it. This also includes supporting static functions cxl_map_registerblock(), cxl_unmap_register_block() and cxl_probe_regs(). Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-8-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/core/regs: Add @dev to cxl_register_mapRobert Richter
The corresponding device of a register mapping is used for devm operations and logging. For operations with struct cxl_register_map the device needs to be kept track separately. To simpify the involved function interfaces, add @dev to cxl_register_map. While at it also reorder function arguments of cxl_map_device_regs() and cxl_map_component_regs() to have the object @cxl_register_map first. As a result a bunch of functions are available to be used with a @cxl_register_map object. This patch is in preparation of reworking the component register setup code. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-7-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl: Rename 'uport' to 'uport_dev'Dan Williams
For symmetry with the recent rename of ->dport_dev for a 'struct cxl_dport', add the "_dev" suffix to the ->uport property of a 'struct cxl_port'. These devices represent the downstream-port-device and upstream-port-device respectively in the CXL/PCIe topology. Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-6-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl: Rename member @dport of struct cxl_dport to @dport_devRobert Richter
Reading code like dport->dport does not immediately suggest that this points to the corresponding device structure of the dport. Rename struct member @dport to @dport_dev. While at it, also rename @new argument of add_dport() to @dport. This better describes the variable as a dport (e.g. new->dport becomes to dport->dport_dev). Co-developed-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-5-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/rch: Prepare for caching the MMIO mapped PCIe AER capabilityDan Williams
Prepare cxl_probe_rcrb() for retrieving more than just the component register block. The RCH AER handling code wants to get back to the AER capability that happens to be MMIO mapped rather then configuration cycles. Move RCRB specific downstream port data, like the RCRB base and the AER capability offset, into its own data structure ('struct cxl_rcrb_info') for cxl_probe_rcrb() to fill. Extend 'struct cxl_dport' to include a 'struct cxl_rcrb_info' attribute. This centralizes all RCRB scanning in one routine. Co-developed-by: Robert Richter <rrichter@amd.com> Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-4-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25cxl/acpi: Probe RCRB later during RCH downstream port creationRobert Richter
The RCRB is extracted already during ACPI CEDT table parsing while the data of this is needed not earlier than dport creation. This implementation comes with drawbacks: During ACPI table scan there is already MMIO access including mapping and unmapping, but only ACPI data should be collected here. The collected data must be transferred through a couple of interfaces until it is finally consumed when creating the dport. This causes complex data structures and function interfaces. Additionally, RCRB parsing will be extended to also extract AER data, it would be much easier do this at a later point during port and dport creation when the data structures are available to hold that data. To simplify all that, probe the RCRB at a later point during RCH downstream port creation. Change ACPI table parser to only extract the base address of either the component registers or the RCRB. Parse and extract the RCRB in devm_cxl_add_rch_dport(). This is in preparation to centralize all RCRB scanning. Signed-off-by: Robert Richter <rrichter@amd.com> Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230622205523.85375-2-terry.bowman@amd.com Co-developed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20230622205523.85375-3-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-30cxl/pci: Find and register CXL PMU devicesJonathan Cameron
CXL PMU devices can be found from entries in the Register Locator DVSEC. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230526095824.16336-4-Jonathan.Cameron@huawei.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-30cxl: Add functions to get an instance of / count regblocks of a given typeJonathan Cameron
Until the recently release CXL 3.0 specification, there was only ever one instance of any given register block pointed to by the Register Block Locator DVSEC. Now, the specification allows for multiple CXL PMU instances, each with their own register block. To enable this add cxl_find_regblock_instance() that takes an index parameter and use that to implement cxl_count_regblock() and cxl_find_regblock(). Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20230526095824.16336-3-Jonathan.Cameron@huawei.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-23cxl/mbox: Add background cmd handling machineryDavidlohr Bueso
This adds support for handling background operations, as defined in the CXL 3.0 spec. Commands that can take too long (over ~2 seconds) can run in the background asynchronously (to the hardware). The driver will deal with such commands synchronously, blocking all other incoming commands for a specified period of time, allowing time-slicing the command such that the caller can send incremental requests to avoid monopolizing the driver/device. Any out of sync (timeout) between the driver and hardware is just disregarded as an invalid state until the next successful submission. Such timeouts are considered a rare occurrence, either a real device problem or a driver issue that needs to reduce the size of the background operation to fit the timeout. On devices where mbox interrupts are supported, this will still use a poller that will wakeup in the specified wait intervals. The irq handler will simply awake the blocked cmd, which is also safe vs a task that is either waking (timing out) or already awoken. Similarly any irq setup error during the probing falls back to polling, thus avoids unnecessarily erroring out. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/20230523170927.20685-5-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-05-18cxl/port: Enable the HDM decoder capability for switch portsDan Williams
Derick noticed, when testing hot plug, that hot-add behaves nominally after a removal. However, if the hot-add is done without a prior removal, CXL.mem accesses fail. It turns out that the original implementation of the port driver and region programming wrongly assumed that platform-firmware always enables the host-bridge HDM decoder capability. Add support turning on switch-level HDM decoders in the case where platform-firmware has not. The implementation is careful to only arrange for the enable to be undone if the current instance of the driver was the one that did the enable. This is to interoperate with platform-firmware that may expect CXL.mem to remain active after the driver is shutdown. This comes at the cost of potentially not shutting down the enable on kexec flows, but it is mitigated by the fact that the related HDM decoders still need to be enabled on an individual basis. Cc: <stable@vger.kernel.org> Reported-by: Derick Marks <derick.w.marks@intel.com> Fixes: 54cdbf845cf7 ("cxl/port: Add a driver for 'struct cxl_port' objects") Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/168437998331.403037.15719879757678389217.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-04cxl/port: Fix find_cxl_root() for RCDs and simplify itDan Williams
The find_cxl_root() helper is used to lookup root decoders and other CXL platform topology information for a given endpoint. It turns out that for RCDs it has never worked. The result of find_cxl_root(&cxlmd->dev) is always NULL for the RCH topology case because it expects to find a cxl_port at the host-bridge. RCH topologies only have the root cxl_port object with the host-bridge as a dport. While there are no reports of this being a problem to date, by inspection region enumeration should crash as a result of this problem, and it does in a local unit test for this scenario. However, an observation that ever since: commit f17b558d6663 ("cxl/pmem: Refactor nvdimm device registration, delete the workqueue") ...all callers of find_cxl_root() occur after the memdev connection to the port topology has been established. That means that find_cxl_root() can be simplified to a walk of the endpoint port topology to the root. Switch to that arrangement which also fixes the RCD bug. Fixes: a32320b71f08 ("cxl/region: Add region autodiscovery") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/168002857715.50647.344876437247313909.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-04-04cxl/hdm: Skip emulation when driver manages mem_enableDan Williams
If the driver is allowed to enable memory operation itself then it can also turn on HDM decoder support at will. With this the second call to cxl_setup_hdm_decoder_from_dvsec(), when an HDM decoder is not committed, is not needed. Fixes: b777e9bec960 ("cxl/hdm: Emulate HDM decoder from DVSEC range registers") Link: http://lore.kernel.org/r/20230220113657.000042e1@huawei.com Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/167703068474.185722.664126485486344246.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-02-25Merge tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxlLinus Torvalds
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() ...