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authorBen Widawsky2021-06-11 12:01:11 -0700
committerDan Williams2021-06-12 10:29:03 -0700
commit6423035fd26c1ecb72f90ecab909e9afa36942b8 (patch)
treeeb20f05003f04fa9164a74df81ae0dc96962affc /drivers/cxl
parent40ba17afdfabb01688c61565dbe02a916241bc05 (diff)
cxl/hdm: Fix decoder count calculation
The decoder count in the HDM decoder capability structure is an encoded field. As defined in the spec: Decoder Count: Reports the number of memory address decoders implemented by the component. 0 – 1 Decoder 1 – 2 Decoders 2 – 4 Decoders 3 – 6 Decoders 4 – 8 Decoders 5 – 10 Decoders All other values are reserved Nothing is actually fixed by this as nothing actually used this mapping yet. Cc: Ira Weiny <ira.weiny@intel.com> Fixes: 08422378c4ad ("cxl/pci: Add HDM decoder capabilities") Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Link: https://lore.kernel.org/r/20210611190111.121295-1-ben.widawsky@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
-rw-r--r--drivers/cxl/core.c2
-rw-r--r--drivers/cxl/cxl.h7
2 files changed, 8 insertions, 1 deletions
diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c
index 1b9ee0b08384..b134b29923ca 100644
--- a/drivers/cxl/core.c
+++ b/drivers/cxl/core.c
@@ -595,7 +595,7 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
hdr = readl(register_block);
- decoder_cnt = FIELD_GET(CXL_HDM_DECODER_COUNT_MASK, hdr);
+ decoder_cnt = cxl_hdm_decoder_count(hdr);
length = 0x20 * decoder_cnt + 0x10;
map->hdm_decoder.valid = true;
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index b988ea288f53..97a273ae3947 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -41,6 +41,13 @@
#define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET 0x1c
#define CXL_HDM_DECODER0_CTRL_OFFSET 0x20
+static inline int cxl_hdm_decoder_count(u32 cap_hdr)
+{
+ int val = FIELD_GET(CXL_HDM_DECODER_COUNT_MASK, cap_hdr);
+
+ return val ? val * 2 : 1;
+}
+
/* CXL 2.0 8.2.8.1 Device Capabilities Array Register */
#define CXLDEV_CAP_ARRAY_OFFSET 0x0
#define CXLDEV_CAP_ARRAY_CAP_ID 0