[PATCH v2 05/38] cxlflash: Hardware AFU for OCXL

Uma Krishnan
2018-02-26T22:20:25Z

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 the OCXL 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>
Acked-by: Matthew R. Ochs <mrochs@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..e3a0a9b 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 OCXL
+ * @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..c7e5c4d
--- /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.
+ */
+
+/* OCXL hardware AFU associated with the host */
+struct ocxl_hw_afu {
+ struct pci_dev *pdev; /* PCI device */
+ struct device *dev; /* Generic device */
+};
--
2.1.0