[PATCH 05/38] cxlflash: Hardware AFU for OpenCXL

[Uma Krishnan <ukrishn@linux.vnet.ibm.com>]

When an adapter is initialized, transport specific configuration and MMIO
mapping details need to be saved. For CXL, this data is managed by the
underlying kernel module. To maintain a separation between the cxlflash
core and underlying transports, introduce a new structure to store data
specific to an OpenCXL AFU.

Initially only the pointers to underlying PCI and generic devices are
added to this new structure - it will be expanded further in future
commits. Services to create and destroy this hardware AFU are added and
integrated in the probe and exit paths of the driver.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
---
 drivers/scsi/cxlflash/backend.h |  1 +
 drivers/scsi/cxlflash/cxl_hw.c  |  6 ++++++
 drivers/scsi/cxlflash/main.c    |  9 +++++++--
 drivers/scsi/cxlflash/ocxl_hw.c | 40 ++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/cxlflash/ocxl_hw.h | 19 +++++++++++++++++++
 5 files changed, 73 insertions(+), 2 deletions(-)
 create mode 100644 drivers/scsi/cxlflash/ocxl_hw.h

diff --git a/drivers/scsi/cxlflash/backend.h b/drivers/scsi/cxlflash/backend.h
index a60f051..f675bcb 100644
--- a/drivers/scsi/cxlflash/backend.h
+++ b/drivers/scsi/cxlflash/backend.h
@@ -36,6 +36,7 @@ struct cxlflash_backend_ops {
 	int (*allocate_afu_irqs)(void *ctx_cookie, int num);
 	void (*free_afu_irqs)(void *ctx_cookie);
 	void * (*create_afu)(struct pci_dev *dev);
+	void (*destroy_afu)(void *afu_cookie);
 	struct file * (*get_fd)(void *ctx_cookie, struct file_operations *fops,
 				int *fd);
 	void * (*fops_get_context)(struct file *file);
diff --git a/drivers/scsi/cxlflash/cxl_hw.c b/drivers/scsi/cxlflash/cxl_hw.c
index db1cada..a1d6d12 100644
--- a/drivers/scsi/cxlflash/cxl_hw.c
+++ b/drivers/scsi/cxlflash/cxl_hw.c
@@ -110,6 +110,11 @@ static void *cxlflash_create_afu(struct pci_dev *dev)
 	return cxl_pci_to_afu(dev);
 }
 
+static void cxlflash_destroy_afu(void *afu)
+{
+	/* Dummy fop for cxl */
+}
+
 static struct file *cxlflash_get_fd(void *ctx_cookie,
 				    struct file_operations *fops, int *fd)
 {
@@ -160,6 +165,7 @@ const struct cxlflash_backend_ops cxlflash_cxl_ops = {
 	.allocate_afu_irqs	= cxlflash_allocate_afu_irqs,
 	.free_afu_irqs		= cxlflash_free_afu_irqs,
 	.create_afu		= cxlflash_create_afu,
+	.destroy_afu		= cxlflash_destroy_afu,
 	.get_fd			= cxlflash_get_fd,
 	.fops_get_context	= cxlflash_fops_get_context,
 	.start_work		= cxlflash_start_work,
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index b83a55a..5d754d1 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -971,6 +971,7 @@ static void cxlflash_remove(struct pci_dev *pdev)
 	case INIT_STATE_AFU:
 		term_afu(cfg);
 	case INIT_STATE_PCI:
+		cfg->ops->destroy_afu(cfg->afu_cookie);
 		pci_disable_device(pdev);
 	case INIT_STATE_NONE:
 		free_mem(cfg);
@@ -3689,8 +3690,6 @@ static int cxlflash_probe(struct pci_dev *pdev,
 
 	pci_set_drvdata(pdev, cfg);
 
-	cfg->afu_cookie = cfg->ops->create_afu(pdev);
-
 	rc = init_pci(cfg);
 	if (rc) {
 		dev_err(dev, "%s: init_pci failed rc=%d\n", __func__, rc);
@@ -3698,6 +3697,12 @@ static int cxlflash_probe(struct pci_dev *pdev,
 	}
 	cfg->init_state = INIT_STATE_PCI;
 
+	cfg->afu_cookie = cfg->ops->create_afu(pdev);
+	if (unlikely(!cfg->afu_cookie)) {
+		dev_err(dev, "%s: create_afu failed\n", __func__);
+		goto out_remove;
+	}
+
 	rc = init_afu(cfg);
 	if (rc && !wq_has_sleeper(&cfg->reset_waitq)) {
 		dev_err(dev, "%s: init_afu failed rc=%d\n", __func__, rc);
diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c
index 58a3182..667cf77 100644
--- a/drivers/scsi/cxlflash/ocxl_hw.c
+++ b/drivers/scsi/cxlflash/ocxl_hw.c
@@ -15,8 +15,48 @@
 #include <misc/ocxl.h>
 
 #include "backend.h"
+#include "ocxl_hw.h"
+
+/**
+ * ocxlflash_destroy_afu() - destroy the AFU structure
+ * @afu_cookie:	AFU to be freed.
+ */
+static void ocxlflash_destroy_afu(void *afu_cookie)
+{
+	struct ocxl_hw_afu *afu = afu_cookie;
+
+	if (!afu)
+		return;
+
+	kfree(afu);
+}
+
+/**
+ * ocxlflash_create_afu() - create the AFU for OpenCXL
+ * @pdev:	PCI device associated with the host.
+ *
+ * Return: AFU on success, NULL on failure
+ */
+static void *ocxlflash_create_afu(struct pci_dev *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ocxl_hw_afu *afu;
+
+	afu = kzalloc(sizeof(*afu), GFP_KERNEL);
+	if (unlikely(!afu)) {
+		dev_err(dev, "%s: HW AFU allocation failed\n", __func__);
+		goto out;
+	}
+
+	afu->pdev = pdev;
+	afu->dev = dev;
+out:
+	return afu;
+}
 
 /* Backend ops to ocxlflash services */
 const struct cxlflash_backend_ops cxlflash_ocxl_ops = {
 	.module			= THIS_MODULE,
+	.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
new file mode 100644
index 0000000..57eb53b
--- /dev/null
+++ b/drivers/scsi/cxlflash/ocxl_hw.h
@@ -0,0 +1,19 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *	       Uma Krishnan <ukrishn@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2018 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+/* OpenCXL hardware AFU associated with the host */
+struct ocxl_hw_afu {
+	struct pci_dev *pdev;		/* PCI device */
+	struct device *dev;		/* Generic device */
+};
-- 
2.1.0