1*50d527f5SAlison SchofieldWhat: /sys/kernel/debug/cxl/memX/inject_poison 2*50d527f5SAlison SchofieldDate: April, 2023 3*50d527f5SAlison SchofieldKernelVersion: v6.4 4*50d527f5SAlison SchofieldContact: linux-cxl@vger.kernel.org 5*50d527f5SAlison SchofieldDescription: 6*50d527f5SAlison Schofield (WO) When a Device Physical Address (DPA) is written to this 7*50d527f5SAlison Schofield attribute, the memdev driver sends an inject poison command to 8*50d527f5SAlison Schofield the device for the specified address. The DPA must be 64-byte 9*50d527f5SAlison Schofield aligned and the length of the injected poison is 64-bytes. If 10*50d527f5SAlison Schofield successful, the device returns poison when the address is 11*50d527f5SAlison Schofield accessed through the CXL.mem bus. Injecting poison adds the 12*50d527f5SAlison Schofield address to the device's Poison List and the error source is set 13*50d527f5SAlison Schofield to Injected. In addition, the device adds a poison creation 14*50d527f5SAlison Schofield event to its internal Informational Event log, updates the 15*50d527f5SAlison Schofield Event Status register, and if configured, interrupts the host. 16*50d527f5SAlison Schofield It is not an error to inject poison into an address that 17*50d527f5SAlison Schofield already has poison present and no error is returned. The 18*50d527f5SAlison Schofield inject_poison attribute is only visible for devices supporting 19*50d527f5SAlison Schofield the capability. 20*50d527f5SAlison Schofield 21*50d527f5SAlison Schofield 22*50d527f5SAlison SchofieldWhat: /sys/kernel/debug/memX/clear_poison 23*50d527f5SAlison SchofieldDate: April, 2023 24*50d527f5SAlison SchofieldKernelVersion: v6.4 25*50d527f5SAlison SchofieldContact: linux-cxl@vger.kernel.org 26*50d527f5SAlison SchofieldDescription: 27*50d527f5SAlison Schofield (WO) When a Device Physical Address (DPA) is written to this 28*50d527f5SAlison Schofield attribute, the memdev driver sends a clear poison command to 29*50d527f5SAlison Schofield the device for the specified address. Clearing poison removes 30*50d527f5SAlison Schofield the address from the device's Poison List and writes 0 (zero) 31*50d527f5SAlison Schofield for 64 bytes starting at address. It is not an error to clear 32*50d527f5SAlison Schofield poison from an address that does not have poison set. If the 33*50d527f5SAlison Schofield device cannot clear poison from the address, -ENXIO is returned. 34*50d527f5SAlison Schofield The clear_poison attribute is only visible for devices 35*50d527f5SAlison Schofield supporting the capability. 36