diff options
| author | Robert Richter <rrichter@amd.com> | 2024-02-16 18:58:43 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2024-03-13 09:52:29 +0300 |
| commit | e0c818e00443ce4a704519d85a21e3c14179e3a6 (patch) | |
| tree | e6c92ec123c81c99429be4cda41f08183be3308d /drivers/cxl/cxlpci.h | |
| parent | ec8ffff3a9f86435996f71299ce729126a7ac8a2 (diff) | |
| download | linux-e0c818e00443ce4a704519d85a21e3c14179e3a6.tar.xz | |
cxl/pci: Get rid of pointer arithmetic reading CDAT table
Reading the CDAT table using DOE requires a Table Access Response
Header in addition to the CDAT entry. In current implementation this
has caused offsets with sizeof(__le32) to the actual buffers. This led
to hardly readable code and even bugs. E.g., see fix of devm_kfree()
in read_cdat_data():
commit c65efe3685f5 ("cxl/cdat: Free correct buffer on checksum error")
Rework code to avoid calculations with sizeof(__le32). Introduce
struct cdat_doe_rsp for this which contains the Table Access Response
Header and a variable payload size for various data structures
afterwards to access the CDAT table and its CDAT Data Structures
without recalculating buffer offsets.
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Fan Ni <nifan.cxl@gmail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240216155844.406996-3-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/cxlpci.h')
| -rw-r--r-- | drivers/cxl/cxlpci.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h index 711b05d9a370..93992a1c8eec 100644 --- a/drivers/cxl/cxlpci.h +++ b/drivers/cxl/cxlpci.h @@ -71,6 +71,15 @@ enum cxl_regloc_type { CXL_REGLOC_RBI_TYPES }; +/* + * Table Access DOE, CDAT Read Entry Response + * + * Spec refs: + * + * CXL 3.1 8.1.11, Table 8-14: Read Entry Response + * CDAT Specification 1.03: 2 CDAT Data Structures + */ + struct cdat_header { __le32 length; u8 revision; @@ -86,6 +95,21 @@ struct cdat_entry_header { } __packed; /* + * The DOE CDAT read response contains a CDAT read entry (either the + * CDAT header or a structure). + */ +union cdat_data { + struct cdat_header header; + struct cdat_entry_header entry; +} __packed; + +/* There is an additional CDAT response header of 4 bytes. */ +struct cdat_doe_rsp { + __le32 doe_header; + u8 data[]; +} __packed; + +/* * CXL v3.0 6.2.3 Table 6-4 * The table indicates that if PCIe Flit Mode is set, then CXL is in 256B flits * mode, otherwise it's 68B flits mode. |