Re: [PATCH v9 09/10] hw/net: GMAC Tx Implementation

[Peter Maydell]

On Tue, 19 Dec 2023 at 21:33, Nabih Estefan <nabihestefan@google.com> wrote:
>
> From: Nabih Estefan Diaz <nabihestefan@google.com>
>
> - Implementation of Transmit function for packets
> - Implementation for reading and writing from and to descriptors in
>   memory for Tx
>
> NOTE: This function implements the steps detailed in the datasheet for
> transmitting messages from the GMAC.
>
> Signed-off-by: Nabih Estefan <nabihestefan@google.com>
> Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
> ---
>  hw/net/npcm_gmac.c | 153 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 153 insertions(+)
>
> diff --git a/hw/net/npcm_gmac.c b/hw/net/npcm_gmac.c
> index fe7b0421ef..69e61b2b67 100644
> --- a/hw/net/npcm_gmac.c
> +++ b/hw/net/npcm_gmac.c
> @@ -265,6 +265,7 @@ static int gmac_write_tx_desc(dma_addr_t addr, struct 
> NPCMGMACTxDesc *desc)
>      }
>      return 0;
>  }
> +
>  static int gmac_rx_transfer_frame_to_buffer(uint32_t rx_buf_len,
>                                              uint32_t *left_frame,
>                                              uint32_t rx_buf_addr,
> @@ -487,6 +488,158 @@ static ssize_t gmac_receive(NetClientState *nc, const 
> uint8_t *buf, size_t len)
>      return len;
>  }
>
> +<<<<<<< HEAD
> +=======

There are still patch conflict markers in this patch.
This suggests you didn't build and test it before sending
it out, which is generally a minimum standard we expect...

> +static int gmac_tx_get_csum(uint32_t tdes1)
> +{
> +    uint32_t mask = TX_DESC_TDES1_CHKSM_INS_CTRL_MASK(tdes1);
> +    int csum = 0;
> +
> +    if (likely(mask > 0)) {
> +        csum |= CSUM_IP;
> +    }
> +    if (likely(mask > 1)) {
> +        csum |= CSUM_TCP | CSUM_UDP;
> +    }
> +
> +    return csum;
> +}
> +
> +static void gmac_try_send_next_packet(NPCMGMACState *gmac)
> +{
> +    /*
> +     * Comments about steps refer to steps for
> +     * transmitting in page 384 of datasheet
> +     */
> +    uint16_t tx_buffer_size = 2048;
> +    g_autofree uint8_t *tx_send_buffer = g_malloc(tx_buffer_size);
> +    uint32_t desc_addr;
> +    struct NPCMGMACTxDesc tx_desc;
> +    uint32_t tx_buf_addr, tx_buf_len;
> +    uint16_t length = 0;
> +    uint8_t *buf = tx_send_buffer;
> +    uint32_t prev_buf_size = 0;
> +    int csum = 0;
> +
> +    /* steps 1&2 */
> +    if (!gmac->regs[R_NPCM_DMA_HOST_TX_DESC]) {
> +        gmac->regs[R_NPCM_DMA_HOST_TX_DESC] =
> +            NPCM_DMA_HOST_TX_DESC_MASK(gmac->regs[R_NPCM_DMA_TX_BASE_ADDR]);
> +    }
> +    desc_addr = gmac->regs[R_NPCM_DMA_HOST_TX_DESC];
> +
> +    while (true) {
> +        gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
> +            NPCM_DMA_STATUS_TX_RUNNING_FETCHING_STATE);
> +        if (gmac_read_tx_desc(desc_addr, &tx_desc)) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "TX Descriptor @ 0x%x can't be read\n",
> +                          desc_addr);
> +            return;
> +        }
> +        /* step 3 */
> +
> +        trace_npcm_gmac_packet_desc_read(DEVICE(gmac)->canonical_path,
> +            desc_addr);
> +        trace_npcm_gmac_debug_desc_data(DEVICE(gmac)->canonical_path, 
> &tx_desc,
> +            tx_desc.tdes0, tx_desc.tdes1, tx_desc.tdes2, tx_desc.tdes3);
> +
> +        /* 1 = DMA Owned, 0 = Software Owned */
> +        if (!(tx_desc.tdes0 & TX_DESC_TDES0_OWN)) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "TX Descriptor @ 0x%x is owned by software\n",
> +                          desc_addr);
> +            gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_TU;
> +            gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
> +                NPCM_DMA_STATUS_TX_SUSPENDED_STATE);
> +            gmac_update_irq(gmac);
> +            return;
> +        }
> +
> +        gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
> +            NPCM_DMA_STATUS_TX_RUNNING_READ_STATE);
> +        /* Give the descriptor back regardless of what happens. */
> +        tx_desc.tdes0 &= ~TX_DESC_TDES0_OWN;
> +
> +        if (tx_desc.tdes1 & TX_DESC_TDES1_FIRST_SEG_MASK) {
> +            csum = gmac_tx_get_csum(tx_desc.tdes1);
> +        }
> +
> +        /* step 4 */
> +        tx_buf_addr = tx_desc.tdes2;
> +        gmac->regs[R_NPCM_DMA_CUR_TX_BUF_ADDR] = tx_buf_addr;
> +        tx_buf_len = TX_DESC_TDES1_BFFR1_SZ_MASK(tx_desc.tdes1);
> +        buf = &tx_send_buffer[prev_buf_size];
> +
> +        if ((prev_buf_size + tx_buf_len) > sizeof(buf)) {
> +            tx_buffer_size = prev_buf_size + tx_buf_len;
> +            tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size);
> +            buf = &tx_send_buffer[prev_buf_size];
> +        }
> +
> +        /* step 5 */
> +        if (dma_memory_read(&address_space_memory, tx_buf_addr, buf,
> +                            tx_buf_len, MEMTXATTRS_UNSPECIFIED)) {
> +            qemu_log_mask(LOG_GUEST_ERROR, "%s: Failed to read packet @ 
> 0x%x\n",
> +                        __func__, tx_buf_addr);
> +            return;
> +        }
> +        length += tx_buf_len;
> +        prev_buf_size += tx_buf_len;
> +
> +        /* If not chained we'll have a second buffer. */
> +        if (!(tx_desc.tdes1 & TX_DESC_TDES1_SEC_ADDR_CHND_MASK)) {
> +            tx_buf_addr = tx_desc.tdes3;
> +            gmac->regs[R_NPCM_DMA_CUR_TX_BUF_ADDR] = tx_buf_addr;
> +            tx_buf_len = TX_DESC_TDES1_BFFR2_SZ_MASK(tx_desc.tdes1);
> +            buf = &tx_send_buffer[prev_buf_size];
> +
> +            if ((prev_buf_size + tx_buf_len) > sizeof(buf)) {
> +                tx_buffer_size = prev_buf_size + tx_buf_len;
> +                tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size);
> +                buf = &tx_send_buffer[prev_buf_size];
> +            }
> +
> +            if (dma_memory_read(&address_space_memory, tx_buf_addr, buf,
> +                                tx_buf_len, MEMTXATTRS_UNSPECIFIED)) {
> +                qemu_log_mask(LOG_GUEST_ERROR,
> +                              "%s: Failed to read packet @ 0x%x\n",
> +                              __func__, tx_buf_addr);
> +                return;
> +            }
> +            length += tx_buf_len;
> +            prev_buf_size += tx_buf_len;
> +        }
> +        if (tx_desc.tdes1 & TX_DESC_TDES1_LAST_SEG_MASK) {
> +            net_checksum_calculate(tx_send_buffer, length, csum);
> +            qemu_send_packet(qemu_get_queue(gmac->nic), tx_send_buffer, 
> length);
> +            trace_npcm_gmac_packet_sent(DEVICE(gmac)->canonical_path, 
> length);
> +            buf = tx_send_buffer;
> +            length = 0;
> +        }
> +
> +        /* step 6 */
> +        gmac_dma_set_state(gmac, NPCM_DMA_STATUS_TX_PROCESS_STATE_SHIFT,
> +            NPCM_DMA_STATUS_TX_RUNNING_CLOSING_STATE);
> +        gmac_write_tx_desc(desc_addr, &tx_desc);
> +        if (tx_desc.tdes1 & TX_DESC_TDES1_TX_END_RING_MASK) {
> +            desc_addr = gmac->regs[R_NPCM_DMA_TX_BASE_ADDR];
> +        } else if (tx_desc.tdes1 & TX_DESC_TDES1_SEC_ADDR_CHND_MASK) {
> +            desc_addr = tx_desc.tdes3;
> +        } else {
> +            desc_addr += sizeof(tx_desc);
> +        }
> +        gmac->regs[R_NPCM_DMA_HOST_TX_DESC] = desc_addr;
> +
> +        /* step 7 */
> +        if (tx_desc.tdes1 & TX_DESC_TDES1_INTERR_COMP_MASK) {
> +            gmac->regs[R_NPCM_DMA_STATUS] |= NPCM_DMA_STATUS_TI;
> +            gmac_update_irq(gmac);
> +        }
> +    }
> +}
> +
> +>>>>>>> 107e0d0181 (hw/net: GMAC Tx Implementation)
>  static void gmac_cleanup(NetClientState *nc)
>  {
>      /* Nothing to do yet. */
> --
> 2.43.0.472.g3155946c3a-goog

-- PMM