summaryrefslogtreecommitdiff
path: root/drivers/cxl
AgeCommit message (Collapse)Author
2024-01-24cxl/region:Fix overflow issue in alloc_hpa()Quanquan Cao
Creating a region with 16 memory devices caused a problem. The div_u64_rem function, used for dividing an unsigned 64-bit number by a 32-bit one, faced an issue when SZ_256M * p->interleave_ways. The result surpassed the maximum limit of the 32-bit divisor (4G), leading to an overflow and a remainder of 0. note: At this point, p->interleave_ways is 16, meaning 16 * 256M = 4G To fix this issue, I replaced the div_u64_rem function with div64_u64_rem and adjusted the type of the remainder. Signed-off-by: Quanquan Cao <caoqq@fujitsu.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Fixes: 23a22cd1c98b ("cxl/region: Allocate HPA capacity to regions") Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-22cxl/pci: Skip irq features if MSI/MSI-X are not supportedIra Weiny
CXL 3.1 Section 3.1.1 states: "A Function on a CXL device must not generate INTx messages if that Function participates in CXL.cache protocol or CXL.mem protocols." The generic CXL memory driver only supports devices which use the CXL.mem protocol. The current driver attempts to allocate MSI/MSI-X vectors in anticipation of their need for mailbox interrupts or event processing. However, the above requirement does not require a device to support interrupts, only that they use MSI/MSI-X. For example, a device may disable mailbox interrupts and either be configured for firmware first or skip event processing and function. Dave Larsen reported that the following Intel / Agilex card does not support interrupts on function 0. CXL: Intel Corporation Device 0ddb (rev 01) (prog-if 10 [CXL Memory Device (CXL 2.x)]) Rather than fail device probe if interrupts are not supported; flag that irqs are not enabled and avoid features which require interrupts. Emit messages appropriate for the situation to aid in debugging should device behavior be unexpected due to a failure to allocate vectors. Note that it is possible for a device to have host based event processing through polling. However, the driver does not support polling and it is not anticipated to be generally required. Leave that functionality to a future patch if such a device comes along. Reported-by: Dave Larsen <davelarsen58@gmail.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-and-tested-by: Davidlohr Bueso <dave@stgolabs.net> Link: https://lore.kernel.org/r/20240117-dont-fail-irq-v2-1-f33f26b0e365@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-12cxl/core: use sysfs_emit() for attr's _show()Shiyang Ruan
sprintf() is deprecated for sysfs, use preferred sysfs_emit() instead. Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Link: https://lore.kernel.org/r/20240112062709.2490947-1-ruansy.fnst@fujitsu.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-09Merge branch 'for-6.8/cxl-cper' into for-6.8/cxlDan Williams
Pick up the CPER to CXL driver integration work for v6.8. Some additional cleanup of cper_estatus_print() messages is needed, but that is to be handled incrementally.
2024-01-09cxl/pci: Register for and process CPER eventsIra Weiny
If the firmware has configured CXL event support to be firmware first the OS can process those events through CPER records. The CXL layer has unique DPA to HPA knowledge and standard event trace parsing in place. CPER records contain Bus, Device, Function information which can be used to identify the PCI device which is sending the event. Change the PCI driver registration to include registration of a CXL CPER callback to process events through the trace subsystem. Use new scoped based management to simplify the handling of the PCI device object. Tested-by: Smita-Koralahalli <Smita.KoralahalliChannabasappa@amd.com> Reviewed-by: Smita-Koralahalli <Smita.KoralahalliChannabasappa@amd.com> Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-9-1bb8a4ca2c7a@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> [djbw: use new pci_dev guard, flip init order] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-09cxl/events: Create a CXL event unionIra Weiny
The CXL CPER and event log records share everything but a UUID/GUID in their structures. Define a cxl_event union without the UUID/GUID to be shared between the CPER and event log record formats. Adjust the code to use this union. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-6-1bb8a4ca2c7a@intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-09cxl/events: Separate UUID from event structuresIra Weiny
The UEFI CXL CPER structure does not include the UUID. Now that the UUID is passed separately to the trace event there is no need to have the UUID in those structures. Move UUID from the event record header to the raw structures. Adjust cxl-test to Create dummy structures for creating test records. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-5-1bb8a4ca2c7a@intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-09cxl/events: Remove passing a UUID to known event tracesIra Weiny
The UUID data is redundant in the known event trace types. The addition of static defines allows the trace macros to create the UUID data inside the trace thus removing unnecessary code. Have well known trace events use static data to set the uuid field based on the event type. Suggested-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-4-1bb8a4ca2c7a@intel.com Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-09cxl/events: Create common event UUID definesIra Weiny
Dan points out in review that the cxl_test code could be made better through the use of UUID's defines rather than being open coded.[1] Create UUID defines and use them rather than open coding them. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: http://lore.kernel.org/r/65738d09e30e2_45e0129451@dwillia2-xfh.jf.intel.com.notmuch [1] Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-3-1bb8a4ca2c7a@intel.com [djbw: clang-format uuid definitions] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> 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.
2024-01-05Merge branch 'for-6.8/cxl-misc' into for-6.8/cxlDan Williams
Pick up some miscellaneous fixups for v6.8.
2024-01-05Merge branch 'for-6.8/cxl-cdat' into for-6.8/cxlDan Williams
Pick up some follow-on fixes for 'cxl_root' reference count leaks.
2024-01-05cxl/events: Promote CXL event structures to a core headerIra Weiny
UEFI code can process CXL events through CPER records. Those records use almost the same format as the CXL events. Lift the CXL event structures to a core header to be shared in later patches. [jic123: drop "CXL rev 3.0" mention] Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-2-1bb8a4ca2c7a@intel.com [djbw: add F: entry to maintainers for include/linux/cxl-event.h] Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-05cxl: Refactor to use __free() for cxl_root allocation in ↵Dave Jiang
cxl_endpoint_port_probe() Use scope-based resource management __free() macro to drop the open coded put_device() in cxl_endpoint_port_probe(). Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170449247973.3779673.15088722836135359275.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-05cxl: Refactor to use __free() for cxl_root allocation in ↵Dave Jiang
cxl_find_nvdimm_bridge() Use scope-based resource management __free() macro to drop the open coded put_device() in cxl_find_nvdimm_bridge(). Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170449247353.3779673.5963704495491343135.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-05cxl: Fix device reference leak in cxl_port_perf_data_calculate()Dave Jiang
cxl_port_perf_data_calculate() calls find_cxl_root() and does not dereference the 'struct device' in the cxl_root->port. find_cxl_root() calls get_device() and takes a reference on the port 'struct device' member. Use the __free() macro to ensure the dereference happens. Fixes: 7a4f148dd8d5 ("cxl: Compute the entire CXL path latency and bandwidth data") Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170449246681.3779673.2288926019977963333.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
2024-01-04cxl/port: Fix decoder initialization when nr_targets > interleave_waysHuang Ying
The decoder_populate_targets() helper walks all of the targets in a port and makes sure they can be looked up in @target_map. Where @target_map is a lookup table from target position to target id (corresponding to a cxl_dport instance). However @target_map is only responsible for conveying the active dport instances as indicated by interleave_ways. When nr_targets > interleave_ways it results in decoder_populate_targets() walking off the end of the valid entries in @target_map. Given target_map is initialized to 0 it results in the dport lookup failing if position 0 is not mapped to a dport with an id of 0: cxl_port port3: Failed to populate active decoder targets cxl_port port3: Failed to add decoder cxl_port port3: Failed to add decoder3.0 cxl_bus_probe: cxl_port port3: probe: -6 This bug also highlights that when the decoder's ->targets[] array is written in cxl_port_setup_targets() it is missing a hold of the targets_lock to synchronize against sysfs readers of the target list. A fix for that is saved for a later patch. Fixes: a5c258021689 ("cxl/bus: Populate the target list at decoder create") Cc: <stable@vger.kernel.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [djbw: rewrite the changelog, find the Fixes: tag] Co-developed-by: Dan Williams <dan.j.williams@intel.com> 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>
2024-01-03cxl/region: fix x9 interleave typoJim Harris
CXL supports x3, x6 and x12 - not x9. Fixes: 80d10a6cee050 ("cxl/region: Add interleave geometry attributes") Signed-off-by: Jim Harris <jim.harris@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Link: https://lore.kernel.org/r/169904271254.204936.8580772404462743630.stgit@ubuntu Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-03cxl/trace: Pass UUID explicitly to event tracesIra Weiny
CXL CPER events are identified by the CPER Section Type GUID. The GUID correlates with the CXL UUID for the event record. It turns out that a CXL CPER record is a strict subset of the CXL event record, only the UUID header field is chopped. In order to unify handling between native and CPER flavors of CXL events, prepare the code for the UUID to be passed in rather than inferred from the record itself. Later patches update the passed in record to only refer to the common data between the formats. Pass the UUID explicitly to each trace event to be able to remove the UUID from the event structures. Originally it was desirable to remove the UUID from the well known event because the UUID value was redundant. However, the trace API was already in place.[1] Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/all/36f2d12934d64a278f2c0313cbd01abc@huawei.com [1] Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-1-1bb8a4ca2c7a@intel.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-01-02Merge branch 'for-6.8/cxl-cdat' into for-6.8/cxlDan Williams
Pick up the CDAT parsing and QOS class infrastructure for v6.8.
2024-01-02cxl/region: use %pap format to print resource_size_tRandy Dunlap
Use "%pap" to print a resource_size_t (phys_addr_t derived type) to prevent build warnings on 32-bit arches (seen on i386 and riscv-32). ../drivers/cxl/core/region.c: In function 'alloc_hpa': ../drivers/cxl/core/region.c:556:25: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 5 has type 'resource_size_t' {aka 'unsigned int'} [-Wformat=] 556 | "HPA allocation error (%ld) for size:%#llx in %s %pr\n", Fixes: 7984d22f1315 ("cxl/region: Add dev_dbg() detail on failure to allocate HPA space") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Fan Ni <fan.ni@samsung.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <linux-cxl@vger.kernel.org> Link: https://lore.kernel.org/r/20240102173917.19718-1-rdunlap@infradead.org Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-24cxl/region: Add dev_dbg() detail on failure to allocate HPA spaceAlison Schofield
When the region driver fails while allocating HPA space for a new region it can be because the parent resource, the CXL Window, has no more available space. In that case, the debug user sees this message: cxl_core:alloc_hpa:555: cxl region2: failed to allocate HPA: -34 Expand the message like this: cxl_core:alloc_hpa:555: cxl region8: HPA allocation error (-34) for size:0x20000000 in CXL Window 0 [mem 0xf010000000-0xf04fffffff flags 0x200] Now the debug user can examine /proc/iomem and consider actions like removing other allocations in that space or reducing the size of their region request. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Link: https://lore.kernel.org/r/20231223004740.1401858-1-alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Check qos_class validity on memdev probeDave Jiang
Add a check to make sure the qos_class for the device will match one of the root decoders qos_class. If no match is found, then the qos_class for the device is set to invalid. Also add a check to ensure that the device's host bridge matches to one of the root decoder's downstream targets. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319626313.2212653.9021004640856081917.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Export sysfs attributes for memory device QoS classDave Jiang
Export qos_class sysfs attributes for the CXL memory device. The QoS clas should show up as /sys/bus/cxl/devices/memX/ram/qos_class for the volatile partition and /sys/bus/cxl/devices/memX/pmem/qos_class for the persistent partition. The QTG ID is retrieved via _DSM after supplying the calculated bandwidth and latency for the entire CXL path from device to the CPU. This ID is used to match up to the root decoder QoS class to determine which CFMWS the memory range of a hotplugged CXL mem device should be assigned under. While there may be multiple DSMAS exported by the device CDAT, the driver will only expose the first QTG ID per partition in sysfs for now. In the future when multiple QTG IDs are necessary, they can be exposed. [1] [1]: https://lore.kernel.org/linux-cxl/167571650007.587790.10040913293130712882.stgit@djiang5-mobl3.local/T/#md2a47b1ead3e1ba08f50eab29a4af1aed1d215ab Suggested-by: Dan Williams <dan.j.williams@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/170319625698.2212653.17544381274847420961.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Store QTG IDs and related info to the CXL memory device contextDave Jiang
Once the QTG ID _DSM is executed successfully, the QTG ID is retrieved from the return package. Create a list of entries in the cxl_memdev context and store the QTG ID as qos_class token and the associated DPA range. This information can be exposed to user space via sysfs in order to help region setup for hot-plugged CXL memory devices. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319625109.2212653.11872111896220384056.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-22cxl: Compute the entire CXL path latency and bandwidth dataDave Jiang
CXL Memory Device SW Guide [1] rev1.0 2.11.2 provides instruction on how to calculate latency and bandwidth for CXL memory device. Calculate minimum bandwidth and total latency for the path from the CXL device to the root port. The QTG id is retrieved by providing the performance data as input and calling the root port callback ->get_qos_class(). The retrieved id is stored with the cxl_port of the CXL device. For example for a device that is directly attached to a host bus: Total Latency = Device Latency (from CDAT) + Dev to Host Bus (HB) Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between HB and CXL device, device CDAT bandwidth, and Generic Port Bandwidth For a device that has a switch in between host bus and CXL device: Total Latency = Device (CDAT) Latency + Dev to Switch Link Latency + Switch (CDAT) Latency + Switch to HB Link Latency + Generic Port Latency Min Bandwidth = Min bandwidth for link bandwidth between CXL device to CXL switch, CXL device CDAT bandwidth, CXL switch CDAT bandwidth, CXL switch to HB bandwidth, and Generic Port Bandwidth. [1]: https://cdrdv2-public.intel.com/643805/643805_CXL%20Memory%20Device%20SW%20Guide_Rev1p0.pdf Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170319624458.2212653.13252496567443656371.stgit@djiang5-mobl3 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 DSLBIS subtable from CDATDave Jiang
Provide a callback to parse the Device Scoped Latency and Bandwidth Information Structure (DSLBIS) in the CDAT structures. The DSLBIS contains the bandwidth and latency information that's tied to a DSMAS handle. The driver will retrieve the read and write latency and bandwidth associated with the DSMAS which is tied to a DPA range. Coherent Device Attribute Table 1.03 2.1 Device 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/170319620005.2212653.7475488478229720542.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>
2023-12-18cxl: Fix unregister_region() callback parameter assignmentDave Jiang
In devm_cxl_add_region(), devm_add_action_or_reset() is called by passing in unregister_region() with data ptr of 'cxlr'. However, in unregister_region(), the passed in parameter is incorrectly assumed to be a 'struct device' rather than the 'cxlr' pointer. The code has been working because 'struct device' is the first member of 'struct cxl_region'. Issue found by inspection. Fix the assignment so that cxlr is pointing directly to the passed in parameter. Not flagged for -stable since there is no functional impact of this fix. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/170258123810.952211.3907381447996426480.stgit@djiang5-mobl3 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-14cxl/pmu: Ensure put_device on pmu devicesIra Weiny
The following kmemleaks were detected when removing the cxl module stack: unreferenced object 0xffff88822616b800 (size 1024): ... backtrace: [<00000000bedc6f83>] kmalloc_trace+0x26/0x90 [<00000000448d1afc>] devm_cxl_pmu_add+0x3a/0x110 [cxl_core] [<00000000ca3bfe16>] 0xffffffffa105213b [<00000000ba7f78dc>] local_pci_probe+0x41/0x90 [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0 ... unreferenced object 0xffff8882260abcc0 (size 16): ... hex dump (first 16 bytes): 70 6d 75 5f 6d 65 6d 30 2e 30 00 26 82 88 ff ff pmu_mem0.0.&.... backtrace: ... [<00000000152b5e98>] dev_set_name+0x43/0x50 [<00000000c228798b>] devm_cxl_pmu_add+0x102/0x110 [cxl_core] [<00000000ca3bfe16>] 0xffffffffa105213b [<00000000ba7f78dc>] local_pci_probe+0x41/0x90 [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0 ... unreferenced object 0xffff8882272af200 (size 256): ... backtrace: [<00000000bedc6f83>] kmalloc_trace+0x26/0x90 [<00000000a14d1813>] device_add+0x4ea/0x890 [<00000000a3f07b47>] devm_cxl_pmu_add+0xbe/0x110 [cxl_core] [<00000000ca3bfe16>] 0xffffffffa105213b [<00000000ba7f78dc>] local_pci_probe+0x41/0x90 [<000000005bb027ac>] pci_device_probe+0xb0/0x1c0 ... devm_cxl_pmu_add() correctly registers a device remove function but it only calls device_del() which is only part of device unregistration. Properly call device_unregister() to free up the memory associated with the device. Fixes: 1ad3f701c399 ("cxl/pci: Find and register CXL PMU devices") Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20231016-pmu-unregister-fix-v1-1-1e2eb2fa3c69@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-08cxl/cdat: Free correct buffer on checksum errorIra Weiny
The new 6.7-rc1 kernel now checks the checksum on CDAT data. While using a branch of Fan's DCD qemu work (and specifying DCD devices), the following splat was observed. WARNING: CPU: 1 PID: 1384 at drivers/base/devres.c:1064 devm_kfree+0x4f/0x60 ... RIP: 0010:devm_kfree+0x4f/0x60 ... ? devm_kfree+0x4f/0x60 read_cdat_data+0x1a0/0x2a0 [cxl_core] cxl_port_probe+0xdf/0x200 [cxl_port] ... The issue in qemu is still unknown but the spat is a straight forward bug in the CDAT checksum processing code. Use a CDAT buffer variable to ensure the devm_free() works correctly on error. Fixes: 670e4e88f3b1 ("cxl: Add checksum verification to CDAT from CXL") Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Robert Richter <rrichter@amd.com> Link: http://lore.kernel.org/r/20231116-fix-cdat-devm-free-v1-1-b148b40707d7@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-07cxl/hdm: Fix dpa translation lockingDan Williams
The helper, cxl_dpa_resource_start(), snapshots the dpa-address of an endpoint-decoder after acquiring the cxl_dpa_rwsem. However, it is sufficient to assert that cxl_dpa_rwsem is held rather than acquire it in the helper. Otherwise, it triggers multiple lockdep reports: 1/ Tracing callbacks are in an atomic context that can not acquire sleeping locks: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1525 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1288, name: bash preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 [..] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023 Call Trace: <TASK> dump_stack_lvl+0x71/0x90 __might_resched+0x1b2/0x2c0 down_read+0x1a/0x190 cxl_dpa_resource_start+0x15/0x50 [cxl_core] cxl_trace_hpa+0x122/0x300 [cxl_core] trace_event_raw_event_cxl_poison+0x1c9/0x2d0 [cxl_core] 2/ The rwsem is already held in the inject poison path: WARNING: possible recursive locking detected 6.7.0-rc2+ #12 Tainted: G W OE N -------------------------------------------- bash/1288 is trying to acquire lock: ffffffffc05f73d0 (cxl_dpa_rwsem){++++}-{3:3}, at: cxl_dpa_resource_start+0x15/0x50 [cxl_core] but task is already holding lock: ffffffffc05f73d0 (cxl_dpa_rwsem){++++}-{3:3}, at: cxl_inject_poison+0x7d/0x1e0 [cxl_core] [..] Call Trace: <TASK> dump_stack_lvl+0x71/0x90 __might_resched+0x1b2/0x2c0 down_read+0x1a/0x190 cxl_dpa_resource_start+0x15/0x50 [cxl_core] cxl_trace_hpa+0x122/0x300 [cxl_core] trace_event_raw_event_cxl_poison+0x1c9/0x2d0 [cxl_core] __traceiter_cxl_poison+0x5c/0x80 [cxl_core] cxl_inject_poison+0x1bc/0x1e0 [cxl_core] This appears to have been an issue since the initial implementation and uncovered by the new cxl-poison.sh test [1]. That test is now passing with these changes. Fixes: 28a3ae4ff66c ("cxl/trace: Add an HPA to cxl_poison trace events") Link: http://lore.kernel.org/r/e4f2716646918135ddbadf4146e92abb659de734.1700615159.git.alison.schofield@intel.com [1] Cc: <stable@vger.kernel.org> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-12-07cxl: Add Support for Get TimestampDavidlohr Bueso
Add the call to the UAPI such that userspace may corelate the timestamps from the device log with system wall time, if, for example there's any sort of inaccuracy or skew in the device. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230829152014.15452-1-dave@stgolabs.net Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-11-29cxl/memdev: Hold region_rwsem during inject and clear poison opsAlison Schofield
Poison inject and clear are supported via debugfs where a privileged user can inject and clear poison to a device physical address. Commit 458ba8189cb4 ("cxl: Add cxl_decoders_committed() helper") added a lockdep assert that highlighted a gap in poison inject and clear functions where holding the dpa_rwsem does not assure that a a DPA is not added to a region. The impact for inject and clear is that if the DPA address being injected or cleared has been attached to a region, but not yet committed, the dev_dbg() message intended to alert the debug user that they are acting on a mapped address is not emitted. Also, the cxl_poison trace event that serves as a log of the inject and clear activity will not include region info. Close this gap by snapshotting an unchangeable region state during poison inject and clear operations. That means holding both the region_rwsem and the dpa_rwsem during the inject and clear ops. Fixes: d2fbc4865802 ("cxl/memdev: Add support for the Inject Poison mailbox command") Fixes: 9690b07748d1 ("cxl/memdev: Add support for the Clear Poison mailbox command") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/08721dc1df0a51e4e38fecd02425c3475912dfd5.1701041440.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-11-29cxl/core: Always hold region_rwsem while reading poison listsAlison Schofield
A read of a device poison list is triggered via a sysfs attribute and the results are logged as kernel trace events of type cxl_poison. The work is managed by either: a) the region driver when one of more regions map the device, or by b) the memdev driver when no regions map the device. In the case of a) the region driver holds the region_rwsem while reading the poison by committed endpoint decoder mappings and for any unmapped resources. This makes sure that the cxl_poison trace event trace reports valid region info. (Region name, HPA, and UUID). In the case of b) the memdev driver holds the dpa_rwsem preventing new DPA resources from being attached to a region. However, it leaves a gap between region attach and decoder commit actions. If a DPA in the gap is in the poison list, the cxl_poison trace event will omit the region info. Close the gap by holding the region_rwsem and the dpa_rwsem when reading poison per memdev. Since both methods now hold both locks, down_read both from the caller. Doing so also addresses the lockdep assert that found this issue: Commit 458ba8189cb4 ("cxl: Add cxl_decoders_committed() helper") Fixes: f0832a586396 ("cxl/region: Provide region info to the cxl_poison trace event") Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/08e8e7ec9a3413b91d51de39e385653494b1eed0.1701041440.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-11-22cxl/hdm: Fix a benign lockdep splatDave Jiang
The new helper "cxl_num_decoders_committed()" added a lockdep assertion to validate that port->commit_end is protected against modification. That assertion fires in init_hdm_decoder() where it is initializing port->commit_end. Given that it is both accessing and writing that property it obstensibly needs the lock. In practice, CXL decoder commit rules (must commit in order) and the in-order discovery of device decoders makes the manipulation of ->commit_end in init_hdm_decoder() safe. However, rather than rely on the subtle rules of CXL hardware, just make the implementation obviously correct from a software perspective. The Fixes: tag is only for cleaning up a lockdep splat, there is no functional issue addressed by this fix. Fixes: 458ba8189cb4 ("cxl: Add cxl_decoders_committed() helper") Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/170025232811.2147250.16376901801315194121.stgit@djiang5-mobl3 Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-11-02cxl/pci: Change CXL AER support check to use native AERTerry Bowman
Native CXL protocol errors are delivered to the OS through AER reporting. The owner of AER owns CXL Protocol error management with respect to _OSC negotiation.[1] CXL device errors are handled by a separate interrupt with native control gated by _OSC control field 'CXL Memory Error Reporting Control'. The CXL driver incorrectly checks for 'CXL Memory Error Reporting Control' before accessing AER registers and caching RCH downport AER registers. Replace the current check in these 2 cases with native AER checks. [1] CXL 3.0 - 9.17.2 CXL _OSC, Table-9-26, Interpretation of CXL _OSC Support Fields, p.641 Fixes: f05fd10d138d ("cxl/pci: Add RCH downstream port AER register discovery") Signed-off-by: Terry Bowman <terry.bowman@amd.com> Reviewed-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> Link: https://lore.kernel.org/r/20231102155232.1421261-1-terry.bowman@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-31cxl/hdm: Remove broken error pathDan Williams
Dan reports that cxl_decoder_commit() potentially leaks a hold of cxl_dpa_rwsem. The potential error case is a "should not" happen scenario, turn it into a "can not" happen scenario by adding the error check to cxl_port_setup_targets() where other setting validation occurs. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: http://lore.kernel.org/r/63295673-5d63-4919-b851-3b06d48734c0@moroto.mountain Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-31cxl/hdm: Fix && vs || bugDan Carpenter
If "info" is NULL then this code will crash. || was intended instead of &&. Fixes: 8ce520fdea24 ("cxl/hdm: Use stored Component Register mappings to map HDM decoder capability") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/60028378-d3d5-4d6d-90fd-f915f061e731@moroto.mountain 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' into cxl/nextDan Williams
Pickup some misc. CXL updates 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.