lkml.org 
[lkml]   [2021]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH net-next v3 5/6] net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum trailer
From
Date
On 3/9/21 6:48 AM, Alex Elder wrote:
> Replace the use of C bit-fields in the rmnet_map_dl_csum_trailer
> structure with a single one-byte field, using constant field masks
> to encode or get at embedded values.
>
> Signed-off-by: Alex Elder <elder@linaro.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> v3: Use BIT(x) and don't use u8_get_bits() for the checksum valid flag
>
> .../ethernet/qualcomm/rmnet/rmnet_map_data.c | 2 +-
> include/linux/if_rmnet.h | 17 +++++++----------
> 2 files changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
> index 3291f252d81b0..72dbbe2c27bd7 100644
> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
> @@ -365,7 +365,7 @@ int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len)
>
> csum_trailer = (struct rmnet_map_dl_csum_trailer *)(skb->data + len);
>
> - if (!csum_trailer->valid) {
> + if (csum_trailer->flags & MAP_CSUM_DL_VALID_FLAG) {

This was the actual problem. The result of the new
test is the reverse of what it should be.

In any case, I'm taking a break from this for a while.

-Alex

> priv->stats.csum_valid_unset++;
> return -EINVAL;
> }
> diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h
> index 22ccc89bb5d8e..a848bb2e0dad0 100644
> --- a/include/linux/if_rmnet.h
> +++ b/include/linux/if_rmnet.h
> @@ -19,21 +19,18 @@ struct rmnet_map_header {
> #define MAP_PAD_LEN_FMASK GENMASK(5, 0)
>
> struct rmnet_map_dl_csum_trailer {
> - u8 reserved1;
> -#if defined(__LITTLE_ENDIAN_BITFIELD)
> - u8 valid:1;
> - u8 reserved2:7;
> -#elif defined (__BIG_ENDIAN_BITFIELD)
> - u8 reserved2:7;
> - u8 valid:1;
> -#else
> -#error "Please fix <asm/byteorder.h>"
> -#endif
> + u8 reserved1;
> + u8 flags; /* MAP_CSUM_DL_*_FMASK */
> __be16 csum_start_offset;
> __be16 csum_length;
> __be16 csum_value;
> } __aligned(1);
>
> +/* rmnet_map_dl_csum_trailer flags field:
> + * VALID: 1 = checksum and length valid; 0 = ignore them
> + */
> +#define MAP_CSUM_DL_VALID_FLAG BIT(0)
> +
> struct rmnet_map_ul_csum_header {
> __be16 csum_start_offset;
> #if defined(__LITTLE_ENDIAN_BITFIELD)
>

\
 
 \ /
  Last update: 2021-03-10 01:14    [W:0.085 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site