/*
* Thunderbolt bus support
*
* Copyright (C) 2017, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/slab.h>
#include "tb.h"
static DEFINE_IDA(tb_domain_ida);
struct bus_type tb_bus_type = {
.name = "thunderbolt",
};
static void tb_domain_release(struct device *dev)
{
struct tb *tb = container_of(dev, struct tb, dev);
tb_ctl_free(tb->ctl);
destroy_workqueue(tb->wq);
ida_simple_remove(&tb_domain_ida, tb->index);
mutex_destroy(&tb->lock);
kfree(tb);
}
struct device_type tb_domain_type = {
.name = "thunderbolt_domain",
.release = tb_domain_release,
};
/**
* tb_domain_alloc() - Allocate a domain
* @nhi: Pointer to the host controller
* @privsize: Size of the connection manager private data
*
* Allocates and initializes a new Thunderbolt domain. Connection
* managers are expected to call this and then fill in @cm_ops
* accordingly.
*
* Call tb_domain_put() to release the domain before it has been added
* to the system.
*
* Return: allocated domain structure on %NULL in case of error
*/
struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
{
struct tb *tb;
/*
* Make sure the structure sizes map with that the hardware
* expects because bit-fields are being used.
*/
BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);
tb = kzalloc(sizeof(*tb) + privsize, GFP_KERNEL);
if (!tb)
return NULL;
tb->nhi = nhi;
mutex_init(&tb->lock);
tb->index = ida_simple_get(&tb_domain_ida, 0, 0, GFP_KERNEL);
if (tb->index < 0)
goto err_free;
tb->wq = alloc_ordered_workqueue("thunderbolt%d", 0, tb->index);
if (!tb->wq)
goto err_remove_ida;
tb->dev.parent = &nhi->pdev->dev;
tb->dev.bus = &tb_bus_type;
tb->dev.type = &tb_domain_type;
dev_set_name(&tb->dev, "domain%d", tb->index);
device_initialize(&tb->dev);
return tb;
err_remove_ida:
ida_simple_remove(&tb_domain_ida, tb->index);
err_free:
kfree(tb);
return NULL;
}
/**
* tb_domain_add() - Add domain to the system
* @tb: Domain to add
*
* Starts the domain and adds it to the system. Hotplugging devices will
* work after this has been returned successfully. In order to remove
* and release the domain after this function has been called, call
* tb_domain_remove().
*
* Return: %0 in case of success and negative errno in case of error
*/
int tb_domain_add(struct tb *tb)
{
int ret;
if (WARN_ON(!tb->cm_ops))
return -EINVAL;
mutex_lock(&tb->lock);
tb->ctl = tb_ctl_alloc(tb->nhi, tb->cm_ops->hotplug, tb);
if (!tb->ctl) {
ret = -ENOMEM;
goto err_unlock;
}
/*
* tb_schedule_hotplug_handler may be called as soon as the config
* channel is started. Thats why we have to hold the lock here.
*/
tb_ctl_start(tb->ctl);
ret = device_add(&tb->dev);
if (ret)
goto err_ctl_stop;
/* Start the domain */
if (tb->cm_ops->start) {
ret = tb->cm_ops->start(tb);
if (ret)
goto err_domain_del;
}
/* This starts event processing */
mutex_unlock(&tb->lock);
return 0;
err_domain_del:
device_del(&tb->dev);
err_ctl_stop:
tb_ctl_stop(tb->ctl);
err_unlock:
mutex_unlock(&tb->lock);
return ret;
}
/**
* tb_domain_remove() - Removes and releases a domain
* @tb: Domain to remove
*
* Stops the domain, removes it from the system and releases all
* resources once the last reference has been released.
*/
void tb_domain_remove(struct tb *tb)
{
mutex_lock(&tb->lock);
if (tb->cm_ops->stop)
tb->cm_ops->stop(tb);
/* Stop the domain control traffic */
tb_ctl_stop(tb->ctl);
mutex_unlock(&tb->lock);
flush_workqueue(tb->wq);
device_unregister(&tb->dev);
}
/**
* tb_domain_suspend_noirq() - Suspend a domain
* @tb: Domain to suspend
*
* Suspends all devices in the domain and stops the control channel.
*/
int tb_domain_suspend_noirq(struct tb *tb)
{
int ret = 0;
/*
* The control channel interrupt is left enabled during suspend
* and taking the lock here prevents any events happening before
* we actually have stopped the domain and the control channel.
*/
mutex_lock(&tb->lock);
if (tb->cm_ops->suspend_noirq)
ret = tb->cm_ops->suspend_noirq(tb);
if (!ret)
tb_ctl_stop(tb->ctl);
mutex_unlock(&tb->lock);
return ret;
}
/**
* tb_domain_resume_noirq() - Resume a domain
* @tb: Domain to resume
*
* Re-starts the control channel, and resumes all devices connected to
* the domain.
*/
int tb_domain_resume_noirq(struct tb *tb)
{
int ret = 0;
mutex_lock(&tb->lock);
tb_ctl_start(tb->ctl);
if (tb->cm_ops->resume_noirq)
ret = tb->cm_ops->resume_noirq(tb);
mutex_unlock(&tb->lock);
return ret;
}
int tb_domain_init(void)
{
return bus_register(&tb_bus_type);
}
void tb_domain_exit(void)
{
bus_unregister(&tb_bus_type);
ida_destroy(&tb_domain_ida);
}
