Re: [PATCH v7 net-next 08/15] net: mvpp2: add FCA RXQ non occupied descriptor threshold

[Marcin Wojtas]

Hi,

wt., 2 lut 2021 o 09:18 <stefanc@xxxxxxxxxxx> napisał(a):
>
> From: Stefan Chulski <stefanc@xxxxxxxxxxx>
>
> The firmware needs to monitor the RX Non-occupied descriptor
> bits for flow control to move to XOFF mode.
> These bits need to be unmasked to be functional, but they will
> not raise interrupts as we leave the RX exception summary
> bit in MVPP2_ISR_RX_TX_MASK_REG clear.
>
> Signed-off-by: Stefan Chulski <stefanc@xxxxxxxxxxx>
> ---
>  drivers/net/ethernet/marvell/mvpp2/mvpp2.h      |  3 ++
>  drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 44 ++++++++++++++++----
>  2 files changed, 40 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
> index 73f087c..ca84995 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
> @@ -295,6 +295,8 @@
>  #define     MVPP2_PON_CAUSE_TXP_OCCUP_DESC_ALL_MASK    0x3fc00000
>  #define     MVPP2_PON_CAUSE_MISC_SUM_MASK              BIT(31)
>  #define MVPP2_ISR_MISC_CAUSE_REG               0x55b0
> +#define MVPP2_ISR_RX_ERR_CAUSE_REG(port)       (0x5520 + 4 * (port))
> +#define     MVPP2_ISR_RX_ERR_CAUSE_NONOCC_MASK 0x00ff
>
>  /* Buffer Manager registers */
>  #define MVPP2_BM_POOL_BASE_REG(pool)           (0x6000 + ((pool) * 4))
> @@ -764,6 +766,7 @@
>  #define MSS_SRAM_SIZE          0x800
>  #define FC_QUANTA              0xFFFF
>  #define FC_CLK_DIVIDER         100
> +#define MSS_THRESHOLD_STOP     768
>
>  /* RX buffer constants */
>  #define MVPP2_SKB_SHINFO_SIZE \
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index 6e59d07..19a3f38 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -1134,14 +1134,19 @@ static inline void mvpp2_qvec_interrupt_disable(struct mvpp2_queue_vector *qvec)
>  static void mvpp2_interrupts_mask(void *arg)
>  {
>         struct mvpp2_port *port = arg;
> +       int cpu = smp_processor_id();
> +       u32 thread;
>
>         /* If the thread isn't used, don't do anything */
> -       if (smp_processor_id() > port->priv->nthreads)
> +       if (cpu >= port->priv->nthreads)

The condition is changed - correctly, but it is a separate fix, that
IMO should go through 'net' tree.

>                 return;
>
> -       mvpp2_thread_write(port->priv,
> -                          mvpp2_cpu_to_thread(port->priv, smp_processor_id()),
> +       thread = mvpp2_cpu_to_thread(port->priv, cpu);
> +
> +       mvpp2_thread_write(port->priv, thread,
>                            MVPP2_ISR_RX_TX_MASK_REG(port->id), 0);
> +       mvpp2_thread_write(port->priv, thread,
> +                          MVPP2_ISR_RX_ERR_CAUSE_REG(port->id), 0);
>  }
>
>  /* Unmask the current thread's Rx/Tx interrupts.
> @@ -1151,20 +1156,25 @@ static void mvpp2_interrupts_mask(void *arg)
>  static void mvpp2_interrupts_unmask(void *arg)
>  {
>         struct mvpp2_port *port = arg;
> -       u32 val;
> +       int cpu = smp_processor_id();
> +       u32 val, thread;
>
>         /* If the thread isn't used, don't do anything */
> -       if (smp_processor_id() > port->priv->nthreads)
> +       if (cpu >= port->priv->nthreads)

Ditto.

Thanks,
Marcin


>                 return;
>
> +       thread = mvpp2_cpu_to_thread(port->priv, cpu);
> +
>         val = MVPP2_CAUSE_MISC_SUM_MASK |
>                 MVPP2_CAUSE_RXQ_OCCUP_DESC_ALL_MASK(port->priv->hw_version);
>         if (port->has_tx_irqs)
>                 val |= MVPP2_CAUSE_TXQ_OCCUP_DESC_ALL_MASK;
>
> -       mvpp2_thread_write(port->priv,
> -                          mvpp2_cpu_to_thread(port->priv, smp_processor_id()),
> +       mvpp2_thread_write(port->priv, thread,
>                            MVPP2_ISR_RX_TX_MASK_REG(port->id), val);
> +       mvpp2_thread_write(port->priv, thread,
> +                          MVPP2_ISR_RX_ERR_CAUSE_REG(port->id),
> +                          MVPP2_ISR_RX_ERR_CAUSE_NONOCC_MASK);
>  }
>
>  static void
> @@ -1189,6 +1199,9 @@ static void mvpp2_interrupts_unmask(void *arg)
>
>                 mvpp2_thread_write(port->priv, v->sw_thread_id,
>                                    MVPP2_ISR_RX_TX_MASK_REG(port->id), val);
> +               mvpp2_thread_write(port->priv, v->sw_thread_id,
> +                                  MVPP2_ISR_RX_ERR_CAUSE_REG(port->id),
> +                                  MVPP2_ISR_RX_ERR_CAUSE_NONOCC_MASK);
>         }
>  }
>
> @@ -2394,6 +2407,20 @@ static void mvpp2_txp_max_tx_size_set(struct mvpp2_port *port)
>         }
>  }
>
> +/* Set the number of non-occupied descriptors threshold */
> +static void mvpp2_set_rxq_free_tresh(struct mvpp2_port *port,
> +                                    struct mvpp2_rx_queue *rxq)
> +{
> +       u32 val;
> +
> +       mvpp2_write(port->priv, MVPP2_RXQ_NUM_REG, rxq->id);
> +
> +       val = mvpp2_read(port->priv, MVPP2_RXQ_THRESH_REG);
> +       val &= ~MVPP2_RXQ_NON_OCCUPIED_MASK;
> +       val |= MSS_THRESHOLD_STOP << MVPP2_RXQ_NON_OCCUPIED_OFFSET;
> +       mvpp2_write(port->priv, MVPP2_RXQ_THRESH_REG, val);
> +}
> +
>  /* Set the number of packets that will be received before Rx interrupt
>   * will be generated by HW.
>   */
> @@ -2649,6 +2676,9 @@ static int mvpp2_rxq_init(struct mvpp2_port *port,
>         mvpp2_rx_pkts_coal_set(port, rxq);
>         mvpp2_rx_time_coal_set(port, rxq);
>
> +       /* Set the number of non occupied descriptors threshold */
> +       mvpp2_set_rxq_free_tresh(port, rxq);
> +
>         /* Add number of descriptors ready for receiving packets */
>         mvpp2_rxq_status_update(port, rxq->id, 0, rxq->size);
>
> --
> 1.9.1
>