1What: /sys/kernel/debug/cxl/memX/inject_poison 2Date: April, 2023 3KernelVersion: v6.4 4Contact: linux-cxl@vger.kernel.org 5Description: 6 (WO) When a Device Physical Address (DPA) is written to this 7 attribute, the memdev driver sends an inject poison command to 8 the device for the specified address. The DPA must be 64-byte 9 aligned and the length of the injected poison is 64-bytes. If 10 successful, the device returns poison when the address is 11 accessed through the CXL.mem bus. Injecting poison adds the 12 address to the device's Poison List and the error source is set 13 to Injected. In addition, the device adds a poison creation 14 event to its internal Informational Event log, updates the 15 Event Status register, and if configured, interrupts the host. 16 It is not an error to inject poison into an address that 17 already has poison present and no error is returned. The 18 inject_poison attribute is only visible for devices supporting 19 the capability. 20 21 22What: /sys/kernel/debug/memX/clear_poison 23Date: April, 2023 24KernelVersion: v6.4 25Contact: linux-cxl@vger.kernel.org 26Description: 27 (WO) When a Device Physical Address (DPA) is written to this 28 attribute, the memdev driver sends a clear poison command to 29 the device for the specified address. Clearing poison removes 30 the address from the device's Poison List and writes 0 (zero) 31 for 64 bytes starting at address. It is not an error to clear 32 poison from an address that does not have poison set. If the 33 device cannot clear poison from the address, -ENXIO is returned. 34 The clear_poison attribute is only visible for devices 35 supporting the capability. 36 37What: /sys/kernel/debug/cxl/einj_types 38Date: January, 2024 39KernelVersion: v6.9 40Contact: linux-cxl@vger.kernel.org 41Description: 42 (RO) Prints the CXL protocol error types made available by 43 the platform in the format "0x<error number> <error type>". 44 The possible error types are (as of ACPI v6.5): 45 0x1000 CXL.cache Protocol Correctable 46 0x2000 CXL.cache Protocol Uncorrectable non-fatal 47 0x4000 CXL.cache Protocol Uncorrectable fatal 48 0x8000 CXL.mem Protocol Correctable 49 0x10000 CXL.mem Protocol Uncorrectable non-fatal 50 0x20000 CXL.mem Protocol Uncorrectable fatal 51 52 The <error number> can be written to einj_inject to inject 53 <error type> into a chosen dport. 54 55What: /sys/kernel/debug/cxl/$dport_dev/einj_inject 56Date: January, 2024 57KernelVersion: v6.9 58Contact: linux-cxl@vger.kernel.org 59Description: 60 (WO) Writing an integer to this file injects the corresponding 61 CXL protocol error into $dport_dev ($dport_dev will be a device 62 name from /sys/bus/pci/devices). The integer to type mapping for 63 injection can be found by reading from einj_types. If the dport 64 was enumerated in RCH mode, a CXL 1.1 error is injected, otherwise 65 a CXL 2.0 error is injected. 66