Re: [PATCH net-next v6 10/15] bnxt_en: Add MPC transmit and completion functions

Responding to some Sashiko comments:
https://sashiko.dev/#/patchset/20260810051358.1244418-1-michael.chan%40broadcom.com

On Sun, Aug 9, 2026 at 10:15 PM Michael Chan <[email protected]> wrote:
> +int bnxt_start_xmit_mpc(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
> +                       void *data, unsigned int len, unsigned long handle)
> +{
(prod);
> +       if (bd_space < bds) {
> +               unsigned int len0 = bd_space * sizeof(*txbd);
> +
> +               memcpy(txbd, data, len0);
> +               prod += bd_space;
> +               txbd = &txr->tx_desc_ring[TX_RING(bp, prod)][TX_IDX(prod)];
> +               bds -= bd_space;
> +               len -= len0;
> +               data += len0;
> +       }
> +       memcpy(txbd, data, len);
Sashiko:
Does this code adequately bounds-check the remaining length when it exceeds
the size of a single descriptor page?
If the provided length is large enough to span more than two pages...

Response:
Yes, the largest MPC command is the ce_add_cmd and the size is about
72 bytes.  It will not span more than 2 pages.

> +int bnxt_mpc_cmp(struct bnxt *bp, struct bnxt_cp_ring_info *cpr, u32 *raw_cons)
> +{

> +               tx_cons = txr->tx_cons;
> +               if (TX_OPAQUE_RING(opaque) != txr->tx_napi_idx) {
> +                       netdev_warn(bp->dev, "Wrong opaque %x, expected ring %x, cons idx %x\n",
> +                                   opaque, txr->tx_napi_idx, txr->tx_cons);
> +                       goto cmp_done;
> +               }
> +               mpc_buf = &txr->tx_mpc_buf_ring[RING_TX(bp, tx_cons)];
> +               mpc_buf->handle = 0;
> +               tx_cons += mpc_buf->inline_bds;
Sashiko:
The docstring for bnxt_start_xmit_mpc() states that bnxt_crypto_mpc_cmp()
will be called with the handle passed back upon successful hardware
completion.
However, mpc_buf->handle is cleared here,...

Response:
The changes are staged. The next patch #11 will hook this up and call
bnxt_crypto_mpc_cmp() with the handle passed back.