]> www.infradead.org Git - users/dwmw2/linux.git/commit
cxl/region: Verify target positions using the ordered target list
authorAlison Schofield <alison.schofield@intel.com>
Wed, 3 Jul 2024 05:29:51 +0000 (22:29 -0700)
committerDave Jiang <dave.jiang@intel.com>
Thu, 11 Jul 2024 23:29:43 +0000 (16:29 -0700)
commit82a3e3a235633aa0575fac9507d648dd80f3437f
treedc748b9df102843772bf9ea392dce916d7e29d2b
parent3b2fedcd75e3991e77c2a8c3ebcab0ea68b2d69d
cxl/region: Verify target positions using the ordered target list

When a root decoder is configured the interleave target list is read
from the BIOS populated CFMWS structure. Per the CXL spec 3.1 Table
9-22 the target list is in interleave order. The CXL driver populates
its decoder target list in the same order and stores it in 'struct
cxl_switch_decoder' field "@target: active ordered target list in
current decoder configuration"

Given the promise of an ordered list, the driver can stop duplicating
the work of BIOS and simply check target positions against the ordered
list during region configuration.

The simplified check against the ordered list is presented here.
A follow-on patch will remove the unused code.

For Modulo arithmetic this is not a fix, only a simplification.
For XOR arithmetic this is a fix for HB IW of 3,6,12.

Fixes: f9db85bfec0d ("cxl/acpi: Support CXL XOR Interleave Math (CXIMS)")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/35d08d3aba08fee0f9b86ab1cef0c25116ca8a55.1719980933.git.alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
drivers/cxl/core/region.c