On 10/14/21 4:39 AM, Guangbin Huang wrote:
> From: Hao Chen <chenhao288@xxxxxxxxxxxxx>
>
> Add support for ethtool to set/get tx copybreak buf size.
What is the unit ?
Frankly, having to size the 'buffer' based on number of slots in TX ring buffer
is not good.
What happens later when/if ethtool -G tx xxxxx' is trying
to change number of slots ?
The 'tx copybreak' should instead give a number of bytes per TX ring slot.
Eg, 128 or 256 bytes.
This is very similar to what drivers using net/core/tso.c do.
They usually use TSO_HEADER_SIZE for this.
>
> Signed-off-by: Hao Chen <chenhao288@xxxxxxxxxxxxx>
> Signed-off-by: Guangbin Huang <huangguangbin2@xxxxxxxxxx>
> ---
> include/uapi/linux/ethtool.h | 1 +
> net/ethtool/common.c | 1 +
> net/ethtool/ioctl.c | 1 +
> 3 files changed, 3 insertions(+)
>
> diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
> index a2223b685451..7bc4b8def12c 100644
> --- a/include/uapi/linux/ethtool.h
> +++ b/include/uapi/linux/ethtool.h
> @@ -231,6 +231,7 @@ enum tunable_id {
> ETHTOOL_RX_COPYBREAK,
> ETHTOOL_TX_COPYBREAK,
> ETHTOOL_PFC_PREVENTION_TOUT, /* timeout in msecs */
> + ETHTOOL_TX_COPYBREAK_BUF_SIZE,
> /*
> * Add your fresh new tunable attribute above and remember to update
> * tunable_strings[] in net/ethtool/common.c
> diff --git a/net/ethtool/common.c b/net/ethtool/common.c
> index c63e0739dc6a..0c5210015911 100644
> --- a/net/ethtool/common.c
> +++ b/net/ethtool/common.c
> @@ -89,6 +89,7 @@ tunable_strings[__ETHTOOL_TUNABLE_COUNT][ETH_GSTRING_LEN] = {
> [ETHTOOL_RX_COPYBREAK] = "rx-copybreak",
> [ETHTOOL_TX_COPYBREAK] = "tx-copybreak",
> [ETHTOOL_PFC_PREVENTION_TOUT] = "pfc-prevention-tout",
> + [ETHTOOL_TX_COPYBREAK_BUF_SIZE] = "tx-copybreak-buf-size",
> };
>
> const char
> diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
> index bf6e8c2f9bf7..617ebc4183d9 100644
> --- a/net/ethtool/ioctl.c
> +++ b/net/ethtool/ioctl.c
> @@ -2383,6 +2383,7 @@ static int ethtool_tunable_valid(const struct ethtool_tunable *tuna)
> switch (tuna->id) {
> case ETHTOOL_RX_COPYBREAK:
> case ETHTOOL_TX_COPYBREAK:
> + case ETHTOOL_TX_COPYBREAK_BUF_SIZE:
> if (tuna->len != sizeof(u32) ||
> tuna->type_id != ETHTOOL_TUNABLE_U32)
> return -EINVAL;
>
