kernel/tools/testing/cxl/test/mem.c, branch linux-rolling-stable

cxl/test: Assign overflow_err_count from log->nr_overflow

2025-11-18T23:21:57Z

mock_get_event() uses an uninitialized local variable, nr_overflow, to populate the overflow_err_count field. That results in incorrect overflow_err_count values in mocked cxl_overflow trace events, such as this case where the records are reported as 0 and should be non-zero: [] cxl_overflow: memdev=mem7 host=cxl_mem.6 serial=7: log=Failure : 0 records from 1763228189130895685 to 1763228193130896180 Fix by using log->nr_overflow and remove the unused local variable. A follow-up change was considered in cxl_mem_get_records_log() to confirm that the overflow_err_count is non-zero when the overflow flag is set [1]. Since the driver has no functional dependency on this constraint, and a device that violates this specific requirement does not cause incorrect driver behavior, no validation check is added. [1] CXL 3.2, Table 8-65 Get Event Records Output Payload Signed-off-by: Alison Schofield Reviewed-by: Ira Weiny Reviewed-by: Dave Jiang > --- Link: https://patch.msgid.link/20251116013036.1713313-1-alison.schofield@intel.com Signed-off-by: Dave Jiang

cxl/test: Remove ret_limit race condition in mock_get_event()

2025-11-18T23:19:48Z

Commit 364ee9f3265e ("cxl/test: Enhance event testing") changed the loop iterator in mock_get_event() from a static constant, CXL_TEST_EVENT_CNT, to a dynamic global variable, ret_limit. The intent was to vary the number of events returned per call to simulate events occurring while logs are being read. However, ret_limit is modified without synchronization. When multiple threads call mock_get_event() concurrently, one thread may read ret_limit, another thread may increment it, and the first thread's loop condition and size calculation see and use the updated value. This is visible during cxl_test module load when all memdevs are initializing simultaneously, which includes getting event records. It is not tied to the cxl-events.sh unit test specifically, as that operates on a single memdev. While no actual harm results (the buffer is always large enough and the record count fields correctly reflect what was written), this is a correctness issue. The race creates an inconsistent state within mock_get_event() and adding variability based on a race appears unintended. Make ret_limit a local variable populated from an atomic counter. Each call gets a stable value that won't change during execution. That preserves the intended behavior of varying the return counts across calls while eliminating the race condition. This implementation uses "+ 1" to produce the full range of 1 to CXL_TEST_EVENT_RET_MAX (4) records. Previously only 1, 2, 3 were produced. Signed-off-by: Alison Schofield Reviewed-by: Ira Weiny Reviewed-by: Dave Jiang > --- Link: https://patch.msgid.link/20251116013819.1713780-1-alison.schofield@intel.com Signed-off-by: Dave Jiang

cxl/test: Simplify fw_buf_checksum_show()

2025-07-04T17:18:52Z

First, just use sha256() instead of a sequence of sha256_init(), sha256_update(), and sha256_final(). The result is the same. Second, use *phN instead of open-coding the conversion of bytes to hex. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250630160645.3198-3-ebiggers@kernel.org Signed-off-by: Eric Biggers

cxl/test: Address missing MODULE_DESCRIPTION warnings for cxl_test

2025-05-06T22:17:49Z

Add MODULE_DESCRIPTION() to address the following warnings: WARNING: modpost: missing MODULE_DESCRIPTION() in test/cxl_test.o WARNING: modpost: missing MODULE_DESCRIPTION() in test/cxl_mock.o WARNING: modpost: missing MODULE_DESCRIPTION() in test/cxl_mock_mem.o [dj: s/CXL test/cxl_test:/ per djbw's comment] Reviewed-by: Dan Williams Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20250429235953.4175408-1-dave.jiang@intel.com Signed-off-by: Dave Jiang

cxl: Fix devm host device for CXL fwctl initialization

2025-04-18T16:33:04Z

Testing revealed the following error message for a CXL memdev that has Feature support: [ 56.690430] cxl mem0: Resources present before probing Attach the allocation of cxl_fwctl to the parent device of cxl_memdev. devm_add_* calls for cxl_memdev should not happen before the memdev probe function or outside the scope of the memdev driver. cxl_test missed this bug because cxl_test always arranges for the cxl_mem driver to be loaded before cxl_mock_mem runs. So the driver core always finds the devres list idle in that case. [DJ: Updated subject title and added commit log suggestion from djbw] Fixes: 858ce2f56b52 ("cxl: Add FWCTL support to CXL") Reviewed-by: Dan Williams Reviewed-by: Alison Schofield Link: https://lore.kernel.org/linux-cxl/6801aea053466_71fe2944c@dwillia2-xfh.jf.intel.com.notmuch/ Link: https://patch.msgid.link/20250418002933.406439-1-dave.jiang@intel.com Signed-off-by: Dave Jiang

Merge tag 'cxl-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2025-04-03T03:04:43Z

Pull Compute Express Link (CXL) updates from Dave Jiang: - Add support for Global Persistent Flush (GPF) - Cleanup of DPA partition metadata handling: - Remove the CXL_DECODER_MIXED enum that's not needed anymore - Introduce helpers to access resource and perf meta data - Introduce 'struct cxl_dpa_partition' and 'struct cxl_range_info' - Make cxl_dpa_alloc() DPA partition number agnostic - Remove cxl_decoder_mode - Cleanup partition size and perf helpers - Remove unused CXL partition values - Add logging support for CXL CPER endpoint and port protocol errors: - Prefix protocol error struct and function names with cxl_ - Move protocol error definitions and structures to a common location - Remove drivers/firmware/efi/cper_cxl.h to include/linux/cper.h - Add support in GHES to process CXL CPER protocol errors - Process CXL CPER protocol errors - Add trace logging for CXL PCIe port RAS errors - Remove redundant gp_port init - Add validation of cxl device serial number - CXL ABI documentation updates/fixups - A series that uses guard() to clean up open coded mutex lockings and remove gotos for error handling. - Some followup patches to support dirty shutdown accounting: - Add helper to retrieve DVSEC offset for dirty shutdown registers - Rename cxl_get_dirty_shutdown() to cxl_arm_dirty_shutdown() - Add support for dirty shutdown count via sysfs - cxl_test support for dirty shutdown - A series to support CXL mailbox Features commands. Mostly in preparation for CXL EDAC code to utilize the Features commands. It's also in preparation for CXL fwctl support to utilize the CXL Features. The commands include "Get Supported Features", "Get Feature", and "Set Feature". - A series to support extended linear cache support described by the ACPI HMAT table. The addition helps enumerate the cache and also provides additional RAS reporting support for configuration with extended linear cache. (and related fixes for the series). - An update to cxl_test to support a 3-way capable CFMWS - A documentation fix to remove unused "mixed mode" * tag 'cxl-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (39 commits) cxl/region: Fix the first aliased address miscalculation cxl/region: Quiet some dev_warn()s in extended linear cache setup cxl/Documentation: Remove 'mixed' from sysfs mode doc cxl: Fix warning from emitting resource_size_t as long long int on 32bit systems cxl/test: Define a CFMWS capable of a 3 way HB interleave cxl/mem: Do not return error if CONFIG_CXL_MCE unset tools/testing/cxl: Set Shutdown State support cxl/pmem: Export dirty shutdown count via sysfs cxl/pmem: Rename cxl_dirty_shutdown_state() cxl/pci: Introduce cxl_gpf_get_dvsec() cxl/pci: Support Global Persistent Flush (GPF) cxl: Document missing sysfs files cxl: Plug typos in ABI doc cxl/pmem: debug invalid serial number data cxl/cdat: Remove redundant gp_port initialization cxl/memdev: Remove unused partition values cxl/region: Drop goto pattern of construct_region() cxl/region: Drop goto pattern in cxl_dax_region_alloc() cxl/core: Use guard() to drop goto pattern of cxl_dpa_alloc() cxl/core: Use guard() to drop the goto pattern of cxl_dpa_free() ...

cxl/test: Add Set Feature support to cxl_test

2025-03-17T17:41:37Z

Add emulation to support Set Feature mailbox command to cxl_test. The only feature supported is the device patrol scrub feature. The set feature allows activation of patrol scrub for the cxl_test emulated device. The command does not support partial data transfer even though the spec allows it. This restriction is to reduce complexity of the emulation given the patrol scrub feature is very minimal. Link: https://patch.msgid.link/r/20250307205648.1021626-8-dave.jiang@intel.com Reviewed-by: Jonathan Cameron Reviewed-by: Dan Williams Reviewed-by: Li Ming Signed-off-by: Dave Jiang Signed-off-by: Jason Gunthorpe

cxl/test: Add Get Feature support to cxl_test

2025-03-17T17:41:37Z

Add emulation of Get Feature command to cxl_test. The feature for device patrol scrub is returned by the emulation code. This is the only feature currently supported by cxl_test. It returns the information for the device patrol scrub feature. Link: https://patch.msgid.link/r/20250307205648.1021626-7-dave.jiang@intel.com Reviewed-by: Jonathan Cameron Reviewed-by: Dan Williams Reviewed-by: Li Ming Signed-off-by: Dave Jiang Signed-off-by: Jason Gunthorpe

cxl: Add FWCTL support to CXL

2025-03-17T17:41:36Z

Add fwctl support code to allow sending of CXL feature commands from userspace through as ioctls via FWCTL. Provide initial setup bits. The CXL PCI probe function will call devm_cxl_setup_fwctl() after the cxl_memdev has been enumerated in order to setup FWCTL char device under the cxl_memdev like the existing memdev char device for issuing CXL raw mailbox commands from userspace via ioctls. Link: https://patch.msgid.link/r/20250307205648.1021626-2-dave.jiang@intel.com Signed-off-by: Dave Jiang Reviewed-by: Li Ming Reviewed-by: Jonathan Cameron Signed-off-by: Jason Gunthorpe

Merge branch 'for-6.15/features' into cxl-for-next

2025-03-17T16:22:59Z

Add CXL Features support. Setup code for enabling in kernel usage of CXL Features. Expecting EDAC/RAS to utilize CXL Features in kernel for things such as memory sparing. Also prepartion for enabling of CXL FWCTL support to issue allowed Features from user space.