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cxl/acpi: Minimize granularity for x1 interleaves

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The kernel enforces that region granularity is >= to the top-level
interleave-granularity for the given CXL window. However, when the CXL
window interleave is x1, i.e. non-interleaved at the host bridge level,
then the specified granularity does not matter. Override the window
specified granularity to the CXL minimum so that any valid region
granularity is >= to the root granularity.

Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/165853776917.2430596.16823264262010844458.stgit@dwillia2-xfh.jf.intel.com
[djbw: add CXL_DECODER_MIN_GRANULARITY per vishal]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2022-07-22 17:56:09 -07:00
parent 2bde6dbebc
commit e77483055c
2 changed files with 8 additions and 0 deletions
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6
drivers/cxl/acpi.c
View File

@ -140,6 +140,12 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
.end = res->end, .end = res->end,
}; };
cxld->interleave_ways = ways; cxld->interleave_ways = ways;
/*
* Minimize the x1 granularity to advertise support for any
* valid region granularity
*/
if (ways == 1)
ig = CXL_DECODER_MIN_GRANULARITY;
cxld->interleave_granularity = ig; cxld->interleave_granularity = ig;
rc = cxl_decoder_add(cxld, target_map); rc = cxl_decoder_add(cxld, target_map);

2
drivers/cxl/cxl.h
View File

@ -248,6 +248,8 @@ enum cxl_decoder_type {
*/ */
#define CXL_DECODER_MAX_INTERLEAVE 16 #define CXL_DECODER_MAX_INTERLEAVE 16
#define CXL_DECODER_MIN_GRANULARITY 256
/** /**
* struct cxl_decoder - Common CXL HDM Decoder Attributes * struct cxl_decoder - Common CXL HDM Decoder Attributes
* @dev: this decoder's device * @dev: this decoder's device