[v2] common/cnxk: enable NIX Tx interrupts errata

  An errata exists whereby NIX may incorrectly overwrite the value in
NIX_SQ_CTX_S[SQ_INT]. This may cause set interrupts to get cleared or
causing an QINT when no error is outstanding.
As a workaround, software should always read all SQ debug registers
and not just rely on NIX_SQINT_E bits set in NIX_SQ_CTX_S[SQ_INT].
Also for detecting SQB faults software must read SQ context and
check id next_sqb is NULL.

Signed-off-by: Harman Kalra <hkalra@marvell.com>
---
V2:
* Rebase on branch code

 drivers/common/cnxk/roc_nix_irq.c | 64 ++++++++++++++++++++++---------
 1 file changed, 46 insertions(+), 18 deletions(-)
  

On Mon, Jan 31, 2022 at 4:22 PM Harman Kalra <hkalra@marvell.com> wrote:
>
> An errata exists whereby NIX may incorrectly overwrite the value in
> NIX_SQ_CTX_S[SQ_INT]. This may cause set interrupts to get cleared or
> causing an QINT when no error is outstanding.
> As a workaround, software should always read all SQ debug registers
> and not just rely on NIX_SQINT_E bits set in NIX_SQ_CTX_S[SQ_INT].
> Also for detecting SQB faults software must read SQ context and
> check id next_sqb is NULL.
>
> Signed-off-by: Harman Kalra <hkalra@marvell.com>

Acked-by: Jerin Jacob <jerinj@marvell.com>
Applied to dpdk-next-net-mrvl/for-next-net. Thanks

> ---
> V2:
> * Rebase on branch code
>
>  drivers/common/cnxk/roc_nix_irq.c | 64 ++++++++++++++++++++++---------
>  1 file changed, 46 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/common/cnxk/roc_nix_irq.c b/drivers/common/cnxk/roc_nix_irq.c
> index 7dcd533ea9..71971ef261 100644
> --- a/drivers/common/cnxk/roc_nix_irq.c
> +++ b/drivers/common/cnxk/roc_nix_irq.c
> @@ -196,18 +196,42 @@ nix_lf_sq_irq_get_and_clear(struct nix *nix, uint16_t sq)
>         return nix_lf_q_irq_get_and_clear(nix, sq, NIX_LF_SQ_OP_INT, ~0x1ff00);
>  }
>
> -static inline void
> +static inline bool
> +nix_lf_is_sqb_null(struct dev *dev, int q)
> +{
> +       bool is_sqb_null = false;
> +       volatile void *ctx;
> +       int rc;
> +
> +       rc = nix_q_ctx_get(dev, NIX_AQ_CTYPE_SQ, q, &ctx);
> +       if (rc) {
> +               plt_err("Failed to get sq context");
> +       } else {
> +               is_sqb_null =
> +                       roc_model_is_cn9k() ?
> +                               (((__io struct nix_sq_ctx_s *)ctx)->next_sqb ==
> +                                0) :
> +                               (((__io struct nix_cn10k_sq_ctx_s *)ctx)
> +                                        ->next_sqb == 0);
> +       }
> +
> +       return is_sqb_null;
> +}
> +
> +static inline uint8_t
>  nix_lf_sq_debug_reg(struct nix *nix, uint32_t off)
>  {
> +       uint8_t err = 0;
>         uint64_t reg;
>
>         reg = plt_read64(nix->base + off);
>         if (reg & BIT_ULL(44)) {
> -               plt_err("SQ=%d err_code=0x%x", (int)((reg >> 8) & 0xfffff),
> -                       (uint8_t)(reg & 0xff));
> +               err = reg & 0xff;
>                 /* Clear valid bit */
>                 plt_write64(BIT_ULL(44), nix->base + off);
>         }
> +
> +       return err;
>  }
>
>  static void
> @@ -229,6 +253,7 @@ nix_lf_q_irq(void *param)
>         struct dev *dev = &nix->dev;
>         int q, cq, rq, sq;
>         uint64_t intr;
> +       uint8_t rc;
>
>         intr = plt_read64(nix->base + NIX_LF_QINTX_INT(qintx));
>         if (intr == 0)
> @@ -269,22 +294,25 @@ nix_lf_q_irq(void *param)
>                 sq = q % nix->qints;
>                 irq = nix_lf_sq_irq_get_and_clear(nix, sq);
>
> -               if (irq & BIT_ULL(NIX_SQINT_LMT_ERR)) {
> -                       plt_err("SQ=%d NIX_SQINT_LMT_ERR", sq);
> -                       nix_lf_sq_debug_reg(nix, NIX_LF_SQ_OP_ERR_DBG);
> -               }
> -               if (irq & BIT_ULL(NIX_SQINT_MNQ_ERR)) {
> -                       plt_err("SQ=%d NIX_SQINT_MNQ_ERR", sq);
> -                       nix_lf_sq_debug_reg(nix, NIX_LF_MNQ_ERR_DBG);
> -               }
> -               if (irq & BIT_ULL(NIX_SQINT_SEND_ERR)) {
> -                       plt_err("SQ=%d NIX_SQINT_SEND_ERR", sq);
> -                       nix_lf_sq_debug_reg(nix, NIX_LF_SEND_ERR_DBG);
> -               }
> -               if (irq & BIT_ULL(NIX_SQINT_SQB_ALLOC_FAIL)) {
> +               /* Detect LMT store error */
> +               rc = nix_lf_sq_debug_reg(nix, NIX_LF_SQ_OP_ERR_DBG);
> +               if (rc)
> +                       plt_err("SQ=%d NIX_SQINT_LMT_ERR, errcode %x", sq, rc);
> +
> +               /* Detect Meta-descriptor enqueue error */
> +               rc = nix_lf_sq_debug_reg(nix, NIX_LF_MNQ_ERR_DBG);
> +               if (rc)
> +                       plt_err("SQ=%d NIX_SQINT_MNQ_ERR, errcode %x", sq, rc);
> +
> +               /* Detect Send error */
> +               rc = nix_lf_sq_debug_reg(nix, NIX_LF_SEND_ERR_DBG);
> +               if (rc)
> +                       plt_err("SQ=%d NIX_SQINT_SEND_ERR, errcode %x", sq, rc);
> +
> +               /* Detect SQB fault, read SQ context to check SQB NULL case */
> +               if (irq & BIT_ULL(NIX_SQINT_SQB_ALLOC_FAIL) ||
> +                   nix_lf_is_sqb_null(dev, q))
>                         plt_err("SQ=%d NIX_SQINT_SQB_ALLOC_FAIL", sq);
> -                       nix_lf_sq_debug_reg(nix, NIX_LF_SEND_ERR_DBG);
> -               }
>         }
>
>         /* Clear interrupt */
> --
> 2.18.0
>