linux/drivers/cxl
Alison Schofield a3e00c964f cxl/region: Calculate a target position in a region interleave
Introduce a calculation to find a target's position in a region
interleave. Perform a self-test of the calculation on user-defined
regions.

The region driver uses the kernel sort() function to put region
targets in relative order. Positions are assigned based on each
target's index in that sorted list. That relative sort doesn't
consider the offset of a port into its parent port which causes
some auto-discovered regions to fail creation. In one failure case,
a 2 + 2 config (2 host bridges each with 2 endpoints), the sort
puts all the targets of one port ahead of another port when they
were expected to be interleaved.

In preparation for repairing the autodiscovery region assembly,
introduce a new method for discovering a target position in the
region interleave.

cxl_calc_interleave_pos() adds a method to find the target position by
ascending from an endpoint to a root decoder. The calculation starts
with the endpoint's local position and position in the parent port. It
traverses towards the root decoder and examines both position and ways
in order to allow the position to be refined all the way to the root
decoder.

This calculation: position = position * parent_ways + parent_pos;
applied iteratively yields the correct position.

Include a self-test that exercises this new position calculation against
every successfully configured user-defined region.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/0ac32c75cf81dd8b86bf07d70ff139d33c2300bc.1698263080.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-10-27 13:04:48 -07:00
..
core cxl/region: Calculate a target position in a region interleave 2023-10-27 13:04:48 -07:00
acpi.c cxl/acpi: Annotate struct cxl_cxims_data with __counted_by 2023-09-22 14:31:04 -07:00
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: Fix sanitize vs decoder setup locking 2023-10-06 00:12:45 -07:00
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/memdev: Fix sanitize vs decoder setup locking 2023-10-06 00:12:45 -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