On Mon, 1 Jul 2019 15:57:52 -0700, Catherine Sullivan wrote:
> Add a driver framework for the Compute Engine Virtual NIC that will be
> available in the future.
>
> At this point the only functionality is loading the driver.
>
> Signed-off-by: Catherine Sullivan <csu...@google.com>
> Signed-off-by: Sagi Shahar <sa...@google.com>
> Signed-off-by: Jon Olson <jonol...@google.com>
> Acked-by: Willem de Bruijn <will...@google.com>
> Reviewed-by: Luigi Rizzo <lri...@google.com>
> +Admin Queue (AQ)
> +----------------
> +The Admin Queue is a PAGE_SIZE memory block, treated as an array of AQ
> +commands, used by the driver to issue commands to the device and set up
> +resources.The driver and the device maintain a count of how many commands
> +have been submitted and executed. To issue AQ commands, the driver must do
> +the following (with proper locking):
> +
> +1) Copy new commands into next available slots in the AQ array
> +2) Increment its counter by he number of new commands
s/he/the/
> +3) Write the counter into the GVE_ADMIN_QUEUE_DOORBELL register
> +4) Poll the ADMIN_QUEUE_EVENT_COUNTER register until it equals
> + the value written to the doorbell, or until a timeout.
> +
> +The device will update the status field in each AQ command reported as
> +executed through the ADMIN_QUEUE_EVENT_COUNTER register.
> +
> +/* This function is not threadsafe - the caller is responsible for any
> + * necessary locks.
> + */
> +int gve_adminq_execute_cmd(struct gve_priv *priv,
> + union gve_adminq_command *cmd_orig)
> +{
> + union gve_adminq_command *cmd;
> + u32 status = 0;
> + u32 prod_cnt;
> +
> + cmd = &priv->adminq[priv->adminq_prod_cnt & priv->adminq_mask];
> + priv->adminq_prod_cnt++;
> + prod_cnt = priv->adminq_prod_cnt;
> +
> + memcpy(cmd, cmd_orig, sizeof(*cmd_orig));
Eh, I guess you don't even need memory barriers around the data movement
to the DMA buffer because of the restriction to x86? :)
> + gve_adminq_kick_cmd(priv, prod_cnt);
> + if (!gve_adminq_wait_for_cmd(priv, prod_cnt)) {
> + dev_err(&priv->pdev->dev, "AQ command timed out, need to reset
> AQ\n");
> + return -ENOTRECOVERABLE;
> + }
> + memcpy(cmd_orig, cmd, sizeof(*cmd));
> + status = be32_to_cpu(READ_ONCE(cmd->status));
> + return gve_adminq_parse_err(&priv->pdev->dev, status);
> +}
> +int gve_adminq_describe_device(struct gve_priv *priv)
> +{
> + struct gve_device_descriptor *descriptor;
> + union gve_adminq_command cmd;
> + dma_addr_t descriptor_bus;
> + int err = 0;
> + u8 *mac;
> + u16 mtu;
> +
> + memset(&cmd, 0, sizeof(cmd));
> + descriptor = dma_alloc_coherent(&priv->pdev->dev, PAGE_SIZE,
> + &descriptor_bus, GFP_KERNEL);
> + if (!descriptor)
> + return -ENOMEM;
> + cmd.opcode = cpu_to_be32(GVE_ADMINQ_DESCRIBE_DEVICE);
> + cmd.describe_device.device_descriptor_addr =
> + cpu_to_be64(descriptor_bus);
> + cmd.describe_device.device_descriptor_version =
> + cpu_to_be32(GVE_ADMINQ_DEVICE_DESCRIPTOR_VERSION);
> + cmd.describe_device.available_length = cpu_to_be32(PAGE_SIZE);
> +
> + err = gve_adminq_execute_cmd(priv, &cmd);
> + if (err)
> + goto free_device_descriptor;
> +
> + mtu = be16_to_cpu(descriptor->mtu);
> + if (mtu < ETH_MIN_MTU) {
> + netif_err(priv, drv, priv->dev, "MTU %d below minimum MTU\n",
> + mtu);
> + err = -EINVAL;
> + goto free_device_descriptor;
> + }
> + priv->dev->max_mtu = mtu;
> + priv->num_event_counters = be16_to_cpu(descriptor->counters);
> + ether_addr_copy(priv->dev->dev_addr, descriptor->mac);
Since you check MTU you can check the address with
is_valid_ether_addr().
Also it's common practice to copy the provisioned MAC to
netdev->perm_addr as well as dev_addr for VFs.
> + mac = descriptor->mac;
> + netif_info(priv, drv, priv->dev, "MAC addr: %pM\n", mac);
> +
> +free_device_descriptor:
> + dma_free_coherent(&priv->pdev->dev, sizeof(*descriptor), descriptor,
> + descriptor_bus);
> + return err;
> +}
Oh, okay, David already applied..
