kernel.git/drivers/cxl/core/core.h, branch linux-6.5.y

cxl/memdev: Fix sanitize vs decoder setup locking

2023-11-20T10:57:18Z

[ Upstream commit 339818380868e34ff2c482db05031bf47a67d609 ] The sanitize operation is destructive and the expectation is that the device is unmapped while in progress. The current implementation does a lockless check for decoders being active, but then does nothing to prevent decoders from racing to be committed. Introduce state tracking to resolve this race. This incidentally cleans up unpriveleged userspace from triggering mmio read cycles by spinning on reading the 'security/state' attribute. Which at a minimum is a waste since the kernel state machine can cache the completion result. Lastly cxl_mem_sanitize() was mistakenly marked EXPORT_SYMBOL() in the original implementation, but an export was never required. Fixes: 0c36b6ad436a ("cxl/mbox: Add sanitization handling machinery") Cc: Davidlohr Bueso Reviewed-by: Jonathan Cameron Reviewed-by: Davidlohr Bueso Reviewed-by: Dave Jiang Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxl

2023-06-26T01:56:13Z

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.

cxl/rch: Prepare for caching the MMIO mapped PCIe AER capability

2023-06-25T18:35:26Z

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 Signed-off-by: Robert Richter Signed-off-by: Terry Bowman Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/20230622205523.85375-4-terry.bowman@amd.com Signed-off-by: Dan Williams

cxl/acpi: Probe RCRB later during RCH downstream port creation

2023-06-25T18:35:20Z

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 Signed-off-by: Terry Bowman Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/20230622205523.85375-2-terry.bowman@amd.com Co-developed-by: Dan Williams Link: https://lore.kernel.org/r/20230622205523.85375-3-terry.bowman@amd.com Signed-off-by: Dan Williams

cxl/pci: Find and register CXL PMU devices

2023-05-30T18:20:35Z

CXL PMU devices can be found from entries in the Register Locator DVSEC. Reviewed-by: Dan Williams Reviewed-by: Dave Jiang Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20230526095824.16336-4-Jonathan.Cameron@huawei.com Signed-off-by: Dan Williams

cxl/memdev: Trace inject and clear poison as cxl_poison events

2023-04-23T19:08:39Z

The cxl_poison trace event allows users to view the history of poison list reads. With the addition of inject and clear poison capabilities, users will expect similar tracing. Add trace types 'Inject' and 'Clear' to the cxl_poison trace_event and trace successful operations only. If the driver finds that the DPA being injected or cleared of poison is mapped in a region, that region info is included in the cxl_poison trace event. Region reconfigurations can make this extra info useless if the debug operations are not carefully managed. Signed-off-by: Alison Schofield Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/e20eb7c3029137b480ece671998c183da0477e2e.1681874357.git.alison.schofield@intel.com Tested-by: Jonathan Cameron Signed-off-by: Dan Williams

cxl/region: Provide region info to the cxl_poison trace event

2023-04-23T18:46:06Z

User space may need to know which region, if any, maps the poison address(es) logged in a cxl_poison trace event. Since the mapping of DPAs (device physical addresses) to a region can change, the kernel must provide this information at the time the poison list is read. The event informs user space that at event this mapped to this , which is poisoned. The cxl_poison trace event is already wired up to log the region name and uuid if it receives param 'struct cxl_region'. In order to provide that cxl_region, add another method for gathering poison - by committed endpoint decoder mappings. This method is only available with CONFIG_CXL_REGION and is only used if a region actually maps the memdev where poison is being read. After the region driver reads the poison list for all the mapped resources, poison is read for any remaining unmapped resources. The default method remains: read the poison by memdev resource. Signed-off-by: Alison Schofield Tested-by: Jonathan Cameron Reviewed-by: Jonathan Cameron Reviewed-by: Ira Weiny Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/438b01ccaa70592539e8eda4eb2b1d617ba03160.1681838292.git.alison.schofield@intel.com Tested-by: Jonathan Cameron Signed-off-by: Dan Williams

cxl/trace: Add TRACE support for CXL media-error records

2023-04-23T18:45:53Z

CXL devices may support the retrieval of a device poison list. Add a new trace event that the CXL subsystem may use to log the media-error records returned in the poison list. Log each media-error record as a cxl_poison trace event of type 'List'. Signed-off-by: Alison Schofield Reviewed-by: Jonathan Cameron Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/de6196f5269483d886ab1834744f82d27189a666.1681838291.git.alison.schofield@intel.com Tested-by: Jonathan Cameron Signed-off-by: Dan Williams

cxl/dax: Create dax devices for CXL RAM regions

2023-02-11T01:33:45Z

While platform firmware takes some responsibility for mapping the RAM capacity of CXL devices present at boot, the OS is responsible for mapping the remainder and hot-added devices. Platform firmware is also responsible for identifying the platform general purpose memory pool, typically DDR attached DRAM, and arranging for the remainder to be 'Soft Reserved'. That reservation allows the CXL subsystem to route the memory to core-mm via memory-hotplug (dax_kmem), or leave it for dedicated access (device-dax). The new 'struct cxl_dax_region' object allows for a CXL memory resource (region) to be published, but also allow for udev and module policy to act on that event. It also prevents cxl_core.ko from having a module loading dependency on any drivers/dax/ modules. Tested-by: Fan Ni Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/167602003896.1924368.10335442077318970468.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams

tools/testing/cxl: Define a fixed volatile configuration to parse

2023-02-11T01:33:04Z

Take two endpoints attached to the first switch on the first host-bridge in the cxl_test topology and define a pre-initialized region. This is a x2 interleave underneath a x1 CXL Window. $ modprobe cxl_test $ # cxl list -Ru { "region":"region3", "resource":"0xf010000000", "size":"512.00 MiB (536.87 MB)", "interleave_ways":2, "interleave_granularity":4096, "decode_state":"commit" } Tested-by: Fan Ni Reviewed-by: Vishal Verma Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/167602000547.1924368.11613151863880268868.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams