linux/drivers/cxl
Alison Schofield 9e4edf1a21 cxl/region: Match auto-discovered region decoders by HPA range
Currently, when the region driver attaches a region to a port, it
selects the ports next available decoder to program.

With the addition of auto-discovered regions, a port decoder has
already been programmed so grabbing the next available decoder can
be a mismatch when there is more than one region using the port.

The failure appears like this with CXL DEBUG enabled:

[] cxl_core:alloc_region_ref:754: cxl region0: endpoint9: HPA order violation region0:[mem 0x14780000000-0x1478fffffff flags 0x200] vs [mem 0x880000000-0x185fffffff flags 0x200]
[] cxl_core:cxl_port_attach_region:972: cxl region0: endpoint9: failed to allocate region reference

When CXL DEBUG is not enabled, there is no failure message. The region
just never materializes. Users can suspect this issue if they know their
firmware has programmed decoders so that more than one region is using
a port. Note that the problem may appear intermittently, ie not on
every reboot.

Add a matching method for auto-discovered regions that finds a decoder
based on an HPA range. The decoder range must exactly match the region
resource parameter.

Fixes: a32320b71f ("cxl/region: Add region autodiscovery")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230905211007.256385-1-alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-09-14 20:46:12 -07:00
..
core cxl/region: Match auto-discovered region decoders by HPA range 2023-09-14 20:46:12 -07:00
acpi.c cxl/acpi: Return 'rc' instead of '0' in cxl_parse_cfmws() 2023-07-18 11:55:09 -06:00
cxl.h Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxl 2023-06-25 18:56:13 -07:00
cxlmem.h cxl/memdev: Only show sanitize sysfs files when supported 2023-07-28 13:16:54 -06:00
cxlpci.h cxl/pci: Find and register CXL PMU devices 2023-05-30 11:20:35 -07:00
Kconfig cxl: fix CONFIG_FW_LOADER dependency 2023-07-14 14:32:22 -06:00
Makefile cxl/pmem: Introduce nvdimm_security_ops with ->get_flags() operation 2022-11-30 16:30:47 -08:00
mem.c Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxl 2023-06-25 18:56:13 -07:00
pci.c cxl/pci: Replace host_bridge->native_aer with pcie_aer_is_native() 2023-09-11 15:24:30 -07:00
pmem.c cxl/mbox: Move mailbox related driver state to its own data structure 2023-06-25 14:31:08 -07:00
pmu.h cxl/pci: Find and register CXL PMU devices 2023-05-30 11:20:35 -07:00
port.c Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxl 2023-06-25 18:56:13 -07:00
security.c Merge branch 'for-6.5/cxl-type-2' into for-6.5/cxl 2023-06-25 17:16:51 -07:00