linux/drivers/thunderbolt/domain.c
Mika Westerberg e6b245ccd5 thunderbolt: Add support for host and device NVM firmware upgrade
Starting from Intel Falcon Ridge the NVM firmware can be upgraded by
using DMA configuration based mailbox commands. If we detect that the
host or device (device support starts from Intel Alpine Ridge) has the
DMA configuration based mailbox we expose NVM information to the
userspace as two separate Linux NVMem devices: nvm_active and
nvm_non_active. The former is read-only portion of the active NVM which
firmware upgrade tools can be use to find out suitable NVM image if the
device identification strings are not enough.

The latter is write-only portion where the new NVM image is to be
written by the userspace. It is up to the userspace to find out right
NVM image (the kernel does very minimal validation). The ICM firmware
itself authenticates the new NVM firmware and fails the operation if it
is not what is expected.

We also expose two new sysfs files per each switch: nvm_version and
nvm_authenticate which can be used to read the active NVM version and
start the upgrade process.

We also introduce safe mode which is the mode a switch goes when it does
not have properly authenticated firmware. In this mode the switch only
accepts a couple of commands including flashing a new NVM firmware image
and triggering power cycle.

This code is based on the work done by Amir Levy and Michael Jamet.

Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:42:43 +02:00

457 lines
10 KiB
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 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",
};
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(&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;
}
static void tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type,
const void *buf, size_t size)
{
struct tb *tb = data;
if (!tb->cm_ops->handle_event) {
tb_warn(tb, "domain does not have event handler\n");
return;
}
tb->cm_ops->handle_event(tb, type, buf, size);
}
/**
* 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_domain_event_cb, 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);
if (tb->cm_ops->driver_ready) {
ret = tb->cm_ops->driver_ready(tb);
if (ret)
goto err_ctl_stop;
}
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_suspend(struct tb *tb)
{
int ret;
mutex_lock(&tb->lock);
if (tb->cm_ops->suspend) {
ret = tb->cm_ops->suspend(tb);
if (ret) {
mutex_unlock(&tb->lock);
return ret;
}
}
mutex_unlock(&tb->lock);
return 0;
}
void tb_domain_complete(struct tb *tb)
{
mutex_lock(&tb->lock);
if (tb->cm_ops->complete)
tb->cm_ops->complete(tb);
mutex_unlock(&tb->lock);
}
/**
* tb_domain_approve_switch() - Approve switch
* @tb: Domain the switch belongs to
* @sw: Switch to approve
*
* This will approve switch by connection manager specific means. In
* case of success the connection manager will create tunnels for all
* supported protocols.
*/
int tb_domain_approve_switch(struct tb *tb, struct tb_switch *sw)
{
struct tb_switch *parent_sw;
if (!tb->cm_ops->approve_switch)
return -EPERM;
/* The parent switch must be authorized before this one */
parent_sw = tb_to_switch(sw->dev.parent);
if (!parent_sw || !parent_sw->authorized)
return -EINVAL;
return tb->cm_ops->approve_switch(tb, sw);
}
/**
* tb_domain_approve_switch_key() - Approve switch and add key
* @tb: Domain the switch belongs to
* @sw: Switch to approve
*
* For switches that support secure connect, this function first adds
* key to the switch NVM using connection manager specific means. If
* adding the key is successful, the switch is approved and connected.
*
* Return: %0 on success and negative errno in case of failure.
*/
int tb_domain_approve_switch_key(struct tb *tb, struct tb_switch *sw)
{
struct tb_switch *parent_sw;
int ret;
if (!tb->cm_ops->approve_switch || !tb->cm_ops->add_switch_key)
return -EPERM;
/* The parent switch must be authorized before this one */
parent_sw = tb_to_switch(sw->dev.parent);
if (!parent_sw || !parent_sw->authorized)
return -EINVAL;
ret = tb->cm_ops->add_switch_key(tb, sw);
if (ret)
return ret;
return tb->cm_ops->approve_switch(tb, sw);
}
/**
* tb_domain_challenge_switch_key() - Challenge and approve switch
* @tb: Domain the switch belongs to
* @sw: Switch to approve
*
* For switches that support secure connect, this function generates
* random challenge and sends it to the switch. The switch responds to
* this and if the response matches our random challenge, the switch is
* approved and connected.
*
* Return: %0 on success and negative errno in case of failure.
*/
int tb_domain_challenge_switch_key(struct tb *tb, struct tb_switch *sw)
{
u8 challenge[TB_SWITCH_KEY_SIZE];
u8 response[TB_SWITCH_KEY_SIZE];
u8 hmac[TB_SWITCH_KEY_SIZE];
struct tb_switch *parent_sw;
struct crypto_shash *tfm;
struct shash_desc *shash;
int ret;
if (!tb->cm_ops->approve_switch || !tb->cm_ops->challenge_switch_key)
return -EPERM;
/* The parent switch must be authorized before this one */
parent_sw = tb_to_switch(sw->dev.parent);
if (!parent_sw || !parent_sw->authorized)
return -EINVAL;
get_random_bytes(challenge, sizeof(challenge));
ret = tb->cm_ops->challenge_switch_key(tb, sw, challenge, response);
if (ret)
return ret;
tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
ret = crypto_shash_setkey(tfm, sw->key, TB_SWITCH_KEY_SIZE);
if (ret)
goto err_free_tfm;
shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
GFP_KERNEL);
if (!shash) {
ret = -ENOMEM;
goto err_free_tfm;
}
shash->tfm = tfm;
shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
memset(hmac, 0, sizeof(hmac));
ret = crypto_shash_digest(shash, challenge, sizeof(hmac), hmac);
if (ret)
goto err_free_shash;
/* The returned HMAC must match the one we calculated */
if (memcmp(response, hmac, sizeof(hmac))) {
ret = -EKEYREJECTED;
goto err_free_shash;
}
crypto_free_shash(tfm);
kfree(shash);
return tb->cm_ops->approve_switch(tb, sw);
err_free_shash:
kfree(shash);
err_free_tfm:
crypto_free_shash(tfm);
return ret;
}
/**
* tb_domain_disconnect_pcie_paths() - Disconnect all PCIe paths
* @tb: Domain whose PCIe paths to disconnect
*
* This needs to be called in preparation for NVM upgrade of the host
* controller. Makes sure all PCIe paths are disconnected.
*
* Return %0 on success and negative errno in case of error.
*/
int tb_domain_disconnect_pcie_paths(struct tb *tb)
{
if (!tb->cm_ops->disconnect_pcie_paths)
return -EPERM;
return tb->cm_ops->disconnect_pcie_paths(tb);
}
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);
tb_switch_exit();
}