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

Uma Krishnan
2018-02-26T22:21:43Z

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>
---
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 */
+};
--
2.1.0