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/openbmc/linux/include/linux/
H A Dif_rmnet.hdiff 16653c16d282e768763b2e8cc78f75df8fd53992 Mon Mar 15 16:51:49 CDT 2021 Alex Elder <elder@linaro.org> net: qualcomm: rmnet: use masks instead of C bit-fields

The actual layout of bits defined in C bit-fields (e.g. int foo : 3)
is implementation-defined. Structures defined in <linux/if_rmnet.h>
address this by specifying all bit-fields twice, to cover two
possible layouts.

I think this pattern is repetitive and noisy, and I find the whole
notion of compiler "bitfield endianness" to be non-intuitive.

Stop using C bit-fields for the command/data flag and the pad length
fields in the rmnet_map structure, and define a single-byte flags
field instead. Define a mask for the single-bit "command" flag,
and another mask for the encoded pad length. The content of both
fields can be accessed using a simple bitwise AND operation.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
/openbmc/linux/drivers/net/ethernet/qualcomm/rmnet/
H A Drmnet_map_data.cdiff 16653c16d282e768763b2e8cc78f75df8fd53992 Mon Mar 15 16:51:49 CDT 2021 Alex Elder <elder@linaro.org> net: qualcomm: rmnet: use masks instead of C bit-fields

The actual layout of bits defined in C bit-fields (e.g. int foo : 3)
is implementation-defined. Structures defined in <linux/if_rmnet.h>
address this by specifying all bit-fields twice, to cover two
possible layouts.

I think this pattern is repetitive and noisy, and I find the whole
notion of compiler "bitfield endianness" to be non-intuitive.

Stop using C bit-fields for the command/data flag and the pad length
fields in the rmnet_map structure, and define a single-byte flags
field instead. Define a mask for the single-bit "command" flag,
and another mask for the encoded pad length. The content of both
fields can be accessed using a simple bitwise AND operation.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
H A Drmnet_handlers.cdiff 16653c16d282e768763b2e8cc78f75df8fd53992 Mon Mar 15 16:51:49 CDT 2021 Alex Elder <elder@linaro.org> net: qualcomm: rmnet: use masks instead of C bit-fields

The actual layout of bits defined in C bit-fields (e.g. int foo : 3)
is implementation-defined. Structures defined in <linux/if_rmnet.h>
address this by specifying all bit-fields twice, to cover two
possible layouts.

I think this pattern is repetitive and noisy, and I find the whole
notion of compiler "bitfield endianness" to be non-intuitive.

Stop using C bit-fields for the command/data flag and the pad length
fields in the rmnet_map structure, and define a single-byte flags
field instead. Define a mask for the single-bit "command" flag,
and another mask for the encoded pad length. The content of both
fields can be accessed using a simple bitwise AND operation.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>