This series converts data structures defined in <linux/if_rmnet.h> so they use integral field values with bitfield masks rather than rely on C bit-fields.
I first proposed doing something like this long ago when my confusion about this code (and the memory layout it was supposed to represent) led me to believe it was erroneous: https://lore.kernel.org/netdev/20190520135354.18628-1-el...@linaro.org/ It came up again recently, when Sharath Chandra Vurukala proposed a new structure in "if_rmnet.h", again using C bit-fields. I asked whether the new structure could use field masks, and Jakub requested that this be done. https://lore.kernel.org/netdev/1613079324-20166-1-git-send-email-shara...@codeaurora.org/ I volunteered to convert the existing RMNet code to use bitfield masks, and that is what I'm doing here. The first three patches are more or less preparation work for the last three. - The first marks two fields in an existing structure explicitly big endian. They are unused by current code, so this should have no impact. - The second simplifies some code that computes the value of a field in a header in a somewhat obfuscated way. - The third eliminates some trivial accessor macros, open-coding them instead. I believe the accessors actually do more harm than good. - The last three convert the structures defined in "if_rmnet.h" so they are defined only with integral fields, each having well-defined byte order. Where sub-fields are needed, field masks are defined so they can be encoded or extracted using functions like be16_get_bits() or u8_encode_bits(), defined in <linux/bitfield.h>. The three structures converted are, in order: rmnet_map_header, rmnet_map_dl_csum_trailer, and rmnet_map_ul_csum_header. -Alex Alex Elder (6): net: qualcomm: rmnet: mark trailer field endianness net: qualcomm: rmnet: simplify some byte order logic net: qualcomm: rmnet: kill RMNET_MAP_GET_*() accessor macros net: qualcomm: rmnet: use field masks instead of C bit-fields net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum trailer net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum header .../ethernet/qualcomm/rmnet/rmnet_handlers.c | 11 ++-- .../net/ethernet/qualcomm/rmnet/rmnet_map.h | 12 ---- .../qualcomm/rmnet/rmnet_map_command.c | 11 +++- .../ethernet/qualcomm/rmnet/rmnet_map_data.c | 60 ++++++++--------- include/linux/if_rmnet.h | 65 +++++++++---------- 5 files changed, 70 insertions(+), 89 deletions(-) -- 2.20.1
