path: root/drivers/thunderbolt/domain.c

/*
 * 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 <linux/random.h>
#include <crypto/hash.h>

#include "tb.h"

static DEFINE_IDA(tb_domain_ida);

static bool match_service_id(const struct tb_service_id *id,
			     const struct tb_service *svc)
{
	if (id->match_flags & TBSVC_MATCH_PROTOCOL_KEY) {
		if (strcmp(id->protocol_key, svc->key))
			return false;
	}

	if (id->match_flags & TBSVC_MATCH_PROTOCOL_ID) {
		if (id->protocol_id != svc->prtcid)
			return false;
	}

	if (id->match_flags & TBSVC_MATCH_PROTOCOL_VERSION) {
		if (id->protocol_version != svc->prtcvers)
			return false;
	}

	if (id->match_flags & TBSVC_MATCH_PROTOCOL_VERSION) {
		if (id->protocol_revision != svc->prtcrevs)
			return false;
	}

	return true;
}

static const struct tb_service_id *__tb_service_match(struct device *dev,
						      struct device_driver *drv)
{
	struct tb_service_driver *driver;
	const struct tb_service_id *ids;
	struct tb_service *svc;

	svc = tb_to_service(dev);
	if (!svc)
		return NULL;

	driver = container_of(drv, struct tb_service_driver, driver);
	if (!driver->id_table)
		return NULL;

	for (ids = driver->id_table; ids->match_flags != 0; ids++) {
		if (match_service_id(ids, svc))
			return ids;
	}

	return NULL;
}

static int tb_service_match(struct device *dev, struct device_driver *drv)
{
	return !!__tb_service_match(dev, drv);
}

static int tb_service_probe(struct device *dev)
{
	struct tb_service *svc = tb_to_service(dev);
	struct tb_service_driver *driver;
	const struct tb_service_id *id;

	driver = container_of(dev->driver, struct tb_service_driver, driver);
	id = __tb_service_match(dev, &driver->driver);

	return driver->probe(svc, id);
}

static int tb_service_remove(struct device *dev)
{
	struct tb_service *svc = tb_to_service(dev);
	struct tb_service_driver *driver;

	driver = container_of(dev->driver, struct tb_service_driver, driver);
	if (driver->remove)
		driver->remove(svc);

	return 0;
}

static void tb_service_shutdown(struct device *dev)
{
	struct tb_service_driver *driver;
	struct tb_service *svc;

	svc = tb_to_service(dev);
	if (!svc || !dev->driver)
		return;

	driver = container_of(dev->driver, struct tb_service_driver, driver);
	if (driver->shutdown)
		driver->shutdown(svc);
}

static const char * const tb_security_names[] = {
	[TB_SECURITY_NONE] = "none",
	[TB_SECURITY_USER] = "user",
	[TB_SECURITY_SECURE] = "secure",
	[TB_SECURITY_DPONLY] = "dponly",
};

static ssize_t security_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct tb *tb = container_of(dev, struct tb, dev);

	return sprintf(buf, "%s\n", tb_security_names[tb->security_level]);
}
static DEVICE_ATTR_RO(security);

static struct attribute *domain_attrs[] = {
	&dev_attr_security.attr,
	NULL,
};

static struct attribute_group domain_attr_group = {
	.attrs = domain_attrs,
};

static const struct attribute_group *domain_attr_groups[] = {
	&domain_attr_group,
	NULL,
};

struct bus_type tb_bus_type = {
	.name = "thunderbolt",
	.match = tb_service_match,
	.probe = tb_service_probe,
	.remove = tb_service_remove,
	.shutdown = tb_service_shutdown,
};

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;
	tb->dev.groups = domain_attr_groups;
	dev_set_name(&