Re: [PATCH v2 11/38] cxlflash: Adapter context support for OCXL

Frederic Barrat
2018-03-22T16:32:02Z

Le 26/02/2018 à 23:21, Uma Krishnan a écrit :
> Add support to create and release the adapter contexts for OCXL and
> provide means to specify certain contexts as a master.
>
> The existing cxlflash core has a design requirement that each host will
> have a single host context available by default. To satisfy this
> requirement, one host adapter context is created when the hardware AFU is
> initialized. This is returned by the get_context() fop.
>
> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
> ---

Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>

> drivers/scsi/cxlflash/ocxl_hw.c | 90 +++++++++++++++++++++++++++++++++++++++++
> drivers/scsi/cxlflash/ocxl_hw.h | 6 +++
> 2 files changed, 96 insertions(+)
>
> diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c
> index bd86eef..d75b873 100644
> --- a/drivers/scsi/cxlflash/ocxl_hw.c
> +++ b/drivers/scsi/cxlflash/ocxl_hw.c
> @@ -18,6 +18,80 @@
> #include "ocxl_hw.h"
>
> /**
> + * ocxlflash_set_master() - sets the context as master
> + * @ctx_cookie: Adapter context to set as master.
> + */
> +static void ocxlflash_set_master(void *ctx_cookie)
> +{
> + struct ocxlflash_context *ctx = ctx_cookie;
> +
> + ctx->master = true;
> +}
> +
> +/**
> + * ocxlflash_get_context() - obtains the context associated with the host
> + * @pdev: PCI device associated with the host.
> + * @afu_cookie: Hardware AFU associated with the host.
> + *
> + * Return: returns the pointer to host adapter context
> + */
> +static void *ocxlflash_get_context(struct pci_dev *pdev, void *afu_cookie)
> +{
> + struct ocxl_hw_afu *afu = afu_cookie;
> +
> + return afu->ocxl_ctx;
> +}
> +
> +/**
> + * ocxlflash_dev_context_init() - allocate and initialize an adapter context
> + * @pdev: PCI device associated with the host.
> + * @afu_cookie: Hardware AFU associated with the host.
> + *
> + * Return: returns the adapter context on success, ERR_PTR on failure
> + */
> +static void *ocxlflash_dev_context_init(struct pci_dev *pdev, void *afu_cookie)
> +{
> + struct ocxl_hw_afu *afu = afu_cookie;
> + struct device *dev = afu->dev;
> + struct ocxlflash_context *ctx;
> + int rc;
> +
> + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> + if (unlikely(!ctx)) {
> + dev_err(dev, "%s: Context allocation failed\n", __func__);
> + rc = -ENOMEM;
> + goto err;
> + }
> +
> + ctx->master = false;
> + ctx->hw_afu = afu;
> +out:
> + return ctx;
> +err:
> + ctx = ERR_PTR(rc);
> + goto out;
> +}
> +
> +/**
> + * ocxlflash_release_context() - releases an adapter context
> + * @ctx_cookie: Adapter context to be released.
> + *
> + * Return: 0 on success, -errno on failure
> + */
> +static int ocxlflash_release_context(void *ctx_cookie)
> +{
> + struct ocxlflash_context *ctx = ctx_cookie;
> + int rc = 0;
> +
> + if (!ctx)
> + goto out;
> +
> + kfree(ctx);
> +out:
> + return rc;
> +}
> +
> +/**
> * ocxlflash_destroy_afu() - destroy the AFU structure
> * @afu_cookie: AFU to be freed.
> */
> @@ -28,6 +102,7 @@ static void ocxlflash_destroy_afu(void *afu_cookie)
> if (!afu)
> return;
>
> + ocxlflash_release_context(afu->ocxl_ctx);
> kfree(afu);
> }
>
> @@ -127,6 +202,7 @@ static int ocxlflash_config_afu(struct pci_dev *pdev, struct ocxl_hw_afu *afu)
> static void *ocxlflash_create_afu(struct pci_dev *pdev)
> {
> struct device *dev = &pdev->dev;
> + struct ocxlflash_context *ctx;
> struct ocxl_hw_afu *afu;
> int rc;
>
> @@ -152,6 +228,16 @@ static void *ocxlflash_create_afu(struct pci_dev *pdev)
> __func__, rc);
> goto err1;
> }
> +
> + ctx = ocxlflash_dev_context_init(pdev, afu);
> + if (IS_ERR(ctx)) {
> + rc = PTR_ERR(ctx);
> + dev_err(dev, "%s: ocxlflash_dev_context_init failed rc=%d\n",
> + __func__, rc);
> + goto err1;
> + }
> +
> + afu->ocxl_ctx = ctx;
> out:
> return afu;
> err1:
> @@ -163,6 +249,10 @@ static void *ocxlflash_create_afu(struct pci_dev *pdev)
> /* Backend ops to ocxlflash services */
> const struct cxlflash_backend_ops cxlflash_ocxl_ops = {
> .module = THIS_MODULE,
> + .set_master = ocxlflash_set_master,
> + .get_context = ocxlflash_get_context,
> + .dev_context_init = ocxlflash_dev_context_init,
> + .release_context = ocxlflash_release_context,
> .create_afu = ocxlflash_create_afu,
> .destroy_afu = ocxlflash_destroy_afu,
> };
> diff --git a/drivers/scsi/cxlflash/ocxl_hw.h b/drivers/scsi/cxlflash/ocxl_hw.h
> index a6f7796..de43c04 100644
> --- a/drivers/scsi/cxlflash/ocxl_hw.h
> +++ b/drivers/scsi/cxlflash/ocxl_hw.h
> @@ -14,6 +14,7 @@
>
> /* OCXL hardware AFU associated with the host */
> struct ocxl_hw_afu {
> + struct ocxlflash_context *ocxl_ctx; /* Host context */
> struct pci_dev *pdev; /* PCI device */
> struct device *dev; /* Generic device */
>
> @@ -27,3 +28,8 @@ struct ocxl_hw_afu {
>
> int max_pasid; /* Maximum number of contexts */
> };
> +
> +struct ocxlflash_context {
> + struct ocxl_hw_afu *hw_afu; /* HW AFU back pointer */
> + bool master; /* Whether this is a master context */
> +};
>