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authorDan Williams <dan.j.williams@intel.com>2022-07-23 03:56:09 +0300
committerDan Williams <dan.j.williams@intel.com>2022-08-02 01:36:33 +0300
commite77483055c325fa629c5835913b07f3dce3ac7fd (patch)
tree495ef024370c09ba46e3e417913dadb969e06858 /drivers/cxl
parent2bde6dbebc1cf02fd1b3d740246b92df1514a370 (diff)
downloadlinux-e77483055c325fa629c5835913b07f3dce3ac7fd.tar.xz
cxl/acpi: Minimize granularity for x1 interleaves
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>
Diffstat (limited to 'drivers/cxl')
-rw-r--r--drivers/cxl/acpi.c6
-rw-r--r--drivers/cxl/cxl.h2
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index eb436268b92c..fb649683dd3a 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -140,6 +140,12 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
.end = res->end,
};
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;
rc = cxl_decoder_add(cxld, target_map);
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 969953ce2609..bc604b7e44fb 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -248,6 +248,8 @@ enum cxl_decoder_type {
*/
#define CXL_DECODER_MAX_INTERLEAVE 16
+#define CXL_DECODER_MIN_GRANULARITY 256
+
/**
* struct cxl_decoder - Common CXL HDM Decoder Attributes
* @dev: this decoder's device