Re: [PATCH v2 06/38] cxlflash: Read host function configuration

Andrew Donnellan
2018-03-07T06:37:32Z

On 27/02/18 09:20, Uma Krishnan wrote:
> Per the OCXL specification, the underlying host can have multiple AFUs
> per function with each function supporting its own configuration. The host
> function configuration is read on the initialization path to evaluate the
> number of functions present and identify the features and configuration of
> the functions present. This data is cached for use in later configuration
> steps. Note that for the OCXL hardware supported by the cxlflash driver,
> only one AFU per function is expected.
>
> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>

Nitpick below

Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>

> ---
> drivers/scsi/cxlflash/ocxl_hw.c | 41 +++++++++++++++++++++++++++++++++++++++++
> drivers/scsi/cxlflash/ocxl_hw.h | 2 ++
> 2 files changed, 43 insertions(+)
>
> diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c
> index e3a0a9b..dc32a73 100644
> --- a/drivers/scsi/cxlflash/ocxl_hw.c
> +++ b/drivers/scsi/cxlflash/ocxl_hw.c
> @@ -32,6 +32,35 @@ static void ocxlflash_destroy_afu(void *afu_cookie)
> }
>
> /**
> + * ocxlflash_config_fn() - configure the host function
> + * @pdev: PCI device associated with the host.
> + * @afu: AFU associated with the host.
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int ocxlflash_config_fn(struct pci_dev *pdev, struct ocxl_hw_afu *afu)
> +{
> + struct ocxl_fn_config *fcfg = &afu->fcfg;
> + struct device *dev = &pdev->dev;
> + int rc = 0;
> +
> + /* Read DVSEC config of the function */
> + rc = ocxl_config_read_function(pdev, fcfg);
> + if (unlikely(rc)) {
> + dev_err(dev, "%s: ocxl_config_read_function failed rc=%d\n",
> + __func__, rc);
> + goto out;
> + }
> +
> + /* Only one AFU per function is supported by ocxlflash */
> + if (fcfg->max_afu_index != 0)
> + dev_warn(dev, "%s: Unexpected AFU index value %d\n",
> + __func__, fcfg->max_afu_index);
> +out:
> + return rc;
> +}
> +
> +/**
> * ocxlflash_create_afu() - create the AFU for OCXL
> * @pdev: PCI device associated with the host.
> *
> @@ -41,6 +70,7 @@ static void *ocxlflash_create_afu(struct pci_dev *pdev)
> {
> struct device *dev = &pdev->dev;
> struct ocxl_hw_afu *afu;
> + int rc;
>
> afu = kzalloc(sizeof(*afu), GFP_KERNEL);
> if (unlikely(!afu)) {
> @@ -50,8 +80,19 @@ static void *ocxlflash_create_afu(struct pci_dev *pdev)
>
> afu->pdev = pdev;
> afu->dev = dev;
> +
> + rc = ocxlflash_config_fn(pdev, afu);
> + if (unlikely(rc)) {
> + dev_err(dev, "%s: Function configuration failed rc=%d\n",
> + __func__, rc);
> + goto err1;
> + }
> out:
> return afu;
> +err1:
> + kfree(afu);
> + afu = NULL;
> + goto out;

I think it would be cleaner to just write return NULL here

> }
>
> /* Backend ops to ocxlflash services */
> diff --git a/drivers/scsi/cxlflash/ocxl_hw.h b/drivers/scsi/cxlflash/ocxl_hw.h
> index c7e5c4d..658f420 100644
> --- a/drivers/scsi/cxlflash/ocxl_hw.h
> +++ b/drivers/scsi/cxlflash/ocxl_hw.h
> @@ -16,4 +16,6 @@
> struct ocxl_hw_afu {
> struct pci_dev *pdev; /* PCI device */
> struct device *dev; /* Generic device */
> +
> + struct ocxl_fn_config fcfg; /* DVSEC config of the function */
> };
>

--
Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com IBM Australia Limited