diff options
| author | Ben Widawsky <ben.widawsky@intel.com> | 2021-06-11 12:01:11 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2021-06-12 10:29:03 -0700 |
| commit | 6423035fd26c1ecb72f90ecab909e9afa36942b8 (patch) | |
| tree | eb20f05003f04fa9164a74df81ae0dc96962affc /drivers/cxl/cxl.h | |
| parent | 40ba17afdfabb01688c61565dbe02a916241bc05 (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/cxl.h')
| -rw-r--r-- | drivers/cxl/cxl.h | 7 |
1 files changed, 7 insertions, 0 deletions
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 |