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CXL Reset is device scoped, requires affected memory to be idle, invalidates CPU caches, restores cached HDM decoder state, and does not request Memory Clear. Signed-off-by: Srirangan Madhavan --- Documentation/ABI/testing/sysfs-bus-pci | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 55ea1db749a1..bfab0a14e8c9 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -153,6 +153,21 @@ Description: "default" enables all supported reset methods in the default ordering. + If present, "cxl_reset" selects CXL Reset for CXL Type 2 + devices that advertise CXL Reset support. The method is only + listed for single-function devices so CXL Reset is not exposed + when the reset could affect another PCI function. + + Before issuing CXL Reset, the kernel rejects the operation if + cached HDM state is unavailable or affected CXL memory is busy. + It reserves affected HDM ranges and, where supported, explicitly + invalidates CPU caches for those ranges. The kernel then disables + CXL.cache, initiates cache write-back where supported, quiesces + the PCI function, and issues CXL Reset. After reset, the kernel + restores PCI config state needed to access HDM MMIO, restores + cached HDM decoder state, and completes PCI reset recovery. + "cxl_reset" does not request CXL Reset Memory Clear. + What: /sys/bus/pci/devices/.../reset Date: July 2009 Contact: Michael S. Tsirkin -- 2.43.0