NTB: Add NTB hardware abstraction layer
Abstract the NTB device behind a programming interface, so that it can
support different hardware and client drivers.
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
diff --git a/drivers/ntb/ntb.c b/drivers/ntb/ntb.c
new file mode 100644
index 0000000..23435f2
--- /dev/null
+++ b/drivers/ntb/ntb.c
@@ -0,0 +1,251 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copy
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Linux driver
+ *
+ * Contact Information:
+ * Allen Hubbe <Allen.Hubbe@emc.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/ntb.h>
+#include <linux/pci.h>
+
+#define DRIVER_NAME "ntb"
+#define DRIVER_DESCRIPTION "PCIe NTB Driver Framework"
+
+#define DRIVER_LICENSE "Dual BSD/GPL"
+#define DRIVER_VERSION "1.0"
+#define DRIVER_RELDATE "24 March 2015"
+#define DRIVER_AUTHOR "Allen Hubbe <Allen.Hubbe@emc.com>"
+
+MODULE_LICENSE(DRIVER_LICENSE);
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
+
+static struct bus_type ntb_bus;
+static void ntb_dev_release(struct device *dev);
+
+int __ntb_register_client(struct ntb_client *client, struct module *mod,
+ const char *mod_name)
+{
+ if (!client)
+ return -EINVAL;
+ if (!ntb_client_ops_is_valid(&client->ops))
+ return -EINVAL;
+
+ memset(&client->drv, 0, sizeof(client->drv));
+ client->drv.bus = &ntb_bus;
+ client->drv.name = mod_name;
+ client->drv.owner = mod;
+
+ return driver_register(&client->drv);
+}
+EXPORT_SYMBOL(__ntb_register_client);
+
+void ntb_unregister_client(struct ntb_client *client)
+{
+ driver_unregister(&client->drv);
+}
+EXPORT_SYMBOL(ntb_unregister_client);
+
+int ntb_register_device(struct ntb_dev *ntb)
+{
+ if (!ntb)
+ return -EINVAL;
+ if (!ntb->pdev)
+ return -EINVAL;
+ if (!ntb->ops)
+ return -EINVAL;
+ if (!ntb_dev_ops_is_valid(ntb->ops))
+ return -EINVAL;
+
+ init_completion(&ntb->released);
+
+ memset(&ntb->dev, 0, sizeof(ntb->dev));
+ ntb->dev.bus = &ntb_bus;
+ ntb->dev.parent = &ntb->pdev->dev;
+ ntb->dev.release = ntb_dev_release;
+ dev_set_name(&ntb->dev, pci_name(ntb->pdev));
+
+ ntb->ctx = NULL;
+ ntb->ctx_ops = NULL;
+ spin_lock_init(&ntb->ctx_lock);
+
+ return device_register(&ntb->dev);
+}
+EXPORT_SYMBOL(ntb_register_device);
+
+void ntb_unregister_device(struct ntb_dev *ntb)
+{
+ device_unregister(&ntb->dev);
+ wait_for_completion(&ntb->released);
+}
+EXPORT_SYMBOL(ntb_unregister_device);
+
+int ntb_set_ctx(struct ntb_dev *ntb, void *ctx,
+ const struct ntb_ctx_ops *ctx_ops)
+{
+ unsigned long irqflags;
+
+ if (!ntb_ctx_ops_is_valid(ctx_ops))
+ return -EINVAL;
+ if (ntb->ctx_ops)
+ return -EINVAL;
+
+ spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+ {
+ ntb->ctx = ctx;
+ ntb->ctx_ops = ctx_ops;
+ }
+ spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+
+ return 0;
+}
+EXPORT_SYMBOL(ntb_set_ctx);
+
+void ntb_clear_ctx(struct ntb_dev *ntb)
+{
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+ {
+ ntb->ctx_ops = NULL;
+ ntb->ctx = NULL;
+ }
+ spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_clear_ctx);
+
+void ntb_link_event(struct ntb_dev *ntb)
+{
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+ {
+ if (ntb->ctx_ops && ntb->ctx_ops->link_event)
+ ntb->ctx_ops->link_event(ntb->ctx);
+ }
+ spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_link_event);
+
+void ntb_db_event(struct ntb_dev *ntb, int vector)
+{
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+ {
+ if (ntb->ctx_ops && ntb->ctx_ops->db_event)
+ ntb->ctx_ops->db_event(ntb->ctx, vector);
+ }
+ spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_db_event);
+
+static int ntb_probe(struct device *dev)
+{
+ struct ntb_dev *ntb;
+ struct ntb_client *client;
+ int rc;
+
+ get_device(dev);
+ ntb = dev_ntb(dev);
+ client = drv_ntb_client(dev->driver);
+
+ rc = client->ops.probe(client, ntb);
+ if (rc)
+ put_device(dev);
+
+ return rc;
+}
+
+static int ntb_remove(struct device *dev)
+{
+ struct ntb_dev *ntb;
+ struct ntb_client *client;
+
+ if (dev->driver) {
+ ntb = dev_ntb(dev);
+ client = drv_ntb_client(dev->driver);
+
+ client->ops.remove(client, ntb);
+ put_device(dev);
+ }
+
+ return 0;
+}
+
+static void ntb_dev_release(struct device *dev)
+{
+ struct ntb_dev *ntb = dev_ntb(dev);
+
+ complete(&ntb->released);
+}
+
+static struct bus_type ntb_bus = {
+ .name = "ntb",
+ .probe = ntb_probe,
+ .remove = ntb_remove,
+};
+
+static int __init ntb_driver_init(void)
+{
+ return bus_register(&ntb_bus);
+}
+module_init(ntb_driver_init);
+
+static void __exit ntb_driver_exit(void)
+{
+ bus_unregister(&ntb_bus);
+}
+module_exit(ntb_driver_exit);
+