Commits on Source (2)
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Dave Jiang authored
Robert reported the following when booting a CXL host with Restricted CXL Host (RCH) topology: [ 39.815379] cxl_acpi ACPI0017:00: not a cxl_port device [ 39.827123] WARNING: CPU: 46 PID: 1754 at drivers/cxl/core/port.c:592 to_cxl_port+0x56/0x70 [cxl_core] ... plus some related subsequent NULL pointer dereference: [ 40.718708] BUG: kernel NULL pointer dereference, address: 00000000000002d8 The iterator to walk the PCIe path did not account for RCH topology. However RCH does not support hotplug and the memory exported by the Restricted CXL Device (RCD) should be covered by HMAT and therefore no access_coordinate is needed. Add check to see if the endpoint device is RCD and skip calculation. Also add a call to cxl_endpoint_get_perf_coordinates() in cxl_test in order to exercise the topology iterator. The dev_is_pci() check added is to help with this test and should be harmless for normal operation. Reported-by: Robert Richter <rrichter@amd.com> Closes: https://lore.kernel.org/all/Ziv8GfSMSbvlBB0h@rric.localdomain/ Fixes: 592780b8 ("cxl: Fix retrieving of access_coordinates in PCIe path") Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Robert Richter <rrichter@amd.com> Reviewed-by: Robert Richter <rrichter@amd.com> Link: https://lore.kernel.org/r/20240426224913.1027420-1-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxlLinus Torvalds authored
Pull cxl fix from Dave Jiang: "Add missing RCH support for endpoint access_coordinate calculation. A late bug was reported by Robert Richter that the Restricted CXL Host (RCH) support was missing in the CXL endpoint access_coordinate calculation. The missing support causes the topology iterator to stumble over a NULL pointer and triggers a kernel OOPS on a platform with CXL 1.1 support. The fix bypasses RCH topology as the access_coordinate calculation is not necessary since RCH does not support hotplug and the memory region exported should be covered by the HMAT table already. A unit test is also added to cxl_test to check against future regressions on the topology iterator" * tag 'cxl-fixes-6.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl: Fix cxl_endpoint_get_perf_coordinate() support for RCH
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