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>

1 files changed, 251 insertions, 0 deletions

diff --git a/drivers/ntb/ntb.c b/drivers/ntb/ntb.c
new file mode 100644
index 000000000000..23435f2a5486
--- /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);
+