Re: [PATCH v2 22/27] nvdimm/ocxl: Implement the heartbeat command

[Jonathan Cameron]

On Tue, 3 Dec 2019 14:46:50 +1100
Alastair D'Silva <alastair@xxxxxxxxxxx> wrote:

> From: Alastair D'Silva <alastair@xxxxxxxxxxx>
> 
> The heartbeat admin command is a simple admin command that exercises
> the communication mechanisms within the controller.
> 
> This patch issues a heartbeat command to the card during init to ensure
> we can communicate with the card's crontroller.

controller

> 
> Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
> ---
>  drivers/nvdimm/ocxl/scm.c | 43 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 43 insertions(+)
> 
> diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c
> index 8a30c887b5ed..e8b34262f397 100644
> --- a/drivers/nvdimm/ocxl/scm.c
> +++ b/drivers/nvdimm/ocxl/scm.c
> @@ -353,6 +353,44 @@ static bool scm_is_usable(const struct scm_data *scm_data)
>  	return true;
>  }
>  
> +/**
> + * scm_heartbeat() - Issue a heartbeat command to the controller
> + * @scm_data: a pointer to the SCM device data
> + * Return: 0 if the controller responded correctly, negative on error
> + */
> +static int scm_heartbeat(struct scm_data *scm_data)
> +{
> +	int rc;
> +
> +	mutex_lock(&scm_data->admin_command.lock);
> +
> +	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_HEARTBEAT);
> +	if (rc)
> +		goto out;
> +
> +	rc = scm_admin_command_execute(scm_data);
> +	if (rc)
> +		goto out;
> +
> +	rc = scm_admin_command_complete_timeout(scm_data, ADMIN_COMMAND_HEARTBEAT);
> +	if (rc < 0) {
> +		dev_err(&scm_data->dev, "Heartbeat timeout\n");
> +		goto out;
> +	}
> +
> +	rc = scm_admin_response(scm_data);
> +	if (rc < 0)
> +		goto out;
> +	if (rc != STATUS_SUCCESS)
> +		scm_warn_status(scm_data, "Unexpected status from heartbeat", rc);
> +
> +	rc = scm_admin_response_handled(scm_data);
> +
> +out:
> +	mutex_unlock(&scm_data->admin_command.lock);
> +	return rc;
> +}
> +
>  /**
>   * allocate_scm_minor() - Allocate a minor number to use for an SCM device
>   * @scm_data: The SCM device to associate the minor with
> @@ -1508,6 +1546,11 @@ static int scm_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  		goto err;
>  	}
>  
> +	if (scm_heartbeat(scm_data)) {
> +		dev_err(&pdev->dev, "SCM Heartbeat failed\n");
> +		goto err;
> +	}
> +
>  	elapsed = 0;
>  	timeout = scm_data->readiness_timeout + scm_data->memory_available_timeout;
>  	while (!scm_is_usable(scm_data)) {