Revision b4cd08aa1f53c831e67dc5c6bc9f9acff27abcba authored by Wolfram Sang on 16 December 2015, 19:05:18 UTC, committed by Wolfram Sang on 19 December 2015, 11:00:37 UTC
When we also are I2C slave, we need to disable runtime PM because the address detection mechanism needs to be active all the time. However, we can reenable runtime PM once the slave instance was unregistered. So, use pm_runtime_get_sync/put to achieve this, since it has proper refcounting. pm_runtime_allow/forbid is like a global knob controllable from userspace which is unsuitable here. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
1 parent e79e72c
ntb.c
/*
* 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, "%s", 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);
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