blob: b7980c856898e7382a6562c7c1b97ed17f549505 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt bus support
*
* Copyright (C) 2017, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#include <linux/device.h>
#include <linux/dmar.h>
#include <linux/idr.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/pm_runtime.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",
[TB_SECURITY_USBONLY] = "usbonly",
};
static ssize_t boot_acl_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tb *tb = container_of(dev, struct tb, dev);
uuid_t *uuids;
ssize_t ret;
int i;
uuids = kcalloc(tb->nboot_acl, sizeof(uuid_t), GFP_KERNEL);
if (!uuids)
return -ENOMEM;
pm_runtime_get_sync(&tb->dev);
if (mutex_lock_interruptible(&tb->lock)) {
ret = -ERESTARTSYS;
goto out;
}
ret = tb->cm_ops->get_boot_acl(tb, uuids, tb->nboot_acl);
if (ret) {
mutex_unlock(&tb->lock);
goto out;
}
mutex_unlock(&tb->lock);
for (ret = 0, i = 0; i < tb->nboot_acl; i++) {
if (!uuid_is_null(&uuids[i]))
ret += snprintf(buf + ret, PAGE_SIZE - ret, "%pUb",
&uuids[i]);
ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s",
i < tb->nboot_acl - 1 ? "," : "\n");
}
out:
pm_runtime_mark_last_busy(&tb->dev);
pm_runtime_put_autosuspend(&tb->dev);
kfree(uuids);
return ret;
}
static ssize_t boot_acl_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct tb *tb = container_of(dev, struct tb, dev);
char *str, *s, *uuid_str;
ssize_t ret = 0;
uuid_t *acl;
int i = 0;
/*
* Make sure the value is not bigger than tb->nboot_acl * UUID
* length + commas and optional "\n". Also the smallest allowable
* string is tb->nboot_acl * ",".
*/
if (count > (UUID_STRING_LEN + 1) * tb->nboot_acl + 1)
return -EINVAL;
if (count < tb->nboot_acl - 1)
return -EINVAL;
str = kstrdup(buf, GFP_KERNEL);
if (!str)
return -ENOMEM;
acl = kcalloc(tb->nboot_acl, sizeof(uuid_t), GFP_KERNEL);
if (!acl) {
ret = -ENOMEM;
goto err_free_str;
}
uuid_str = strim(str);
while ((s = strsep(&uuid_str, ",")) != NULL && i < tb->nboot_acl) {
size_t len = strlen(s);
if (len) {
if (len != UUID_STRING_LEN) {
ret = -EINVAL;
goto err_free_acl;
}
ret = uuid_parse(s, &acl[i]);
if (ret)
goto err_free_acl;
}
i++;
}
if (s || i < tb->nboot_acl) {
ret = -EINVAL;
goto err_free_acl;
}
pm_runtime_get_sync(&tb->dev);
if (mutex_lock_interruptible(&tb->lock)) {
ret = -ERESTARTSYS;
goto err_rpm_put;
}
ret = tb->cm_ops->set_boot_acl(tb, acl, tb->nboot_acl);
if (!ret) {
/* Notify userspace about the change */
kobject_uevent(&tb->dev.kobj, KOBJ_CHANGE);
}
mutex_unlock(&tb->lock);
err_rpm_put:
pm_runtime_mark_last_busy(&tb->dev);
pm_runtime_put_autosuspend(&tb->dev);
err_free_acl:
kfree(acl);
err_free_str:
kfree(str);
return ret ?: count;
}
static DEVICE_ATTR_RW(boot_acl);
static ssize_t iommu_dma_protection_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
/*
* Kernel DMA protection is a feature where Thunderbolt security is
* handled natively using IOMMU. It is enabled when IOMMU is
* enabled and ACPI DMAR table has DMAR_PLATFORM_OPT_IN set.
*/
return sprintf(buf, "%d\n",
iommu_present(&pci_bus_type) && dmar_platform_optin());
}
static DEVICE_ATTR_RO(iommu_dma_protection);
static ssize_t security_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tb *tb = container_of(dev, struct tb, dev);
const char *name = "unknown";
if (tb->security_level < ARRAY_SIZE(tb_security_names))
name = tb_security_names[tb->security_level];
return sprintf(buf, "%s\n", name);
}
static DEVICE_ATTR_RO(security);
static struct attribute *domain_attrs[] = {
&dev_attr_boot_acl.attr,
&dev_attr_iommu_dma_protection.attr,
&dev_attr_security.attr,
NULL,
};
static umode_t domain_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct tb *tb = container_of(dev, struct tb, dev);
if (attr == &dev_attr_boot_acl.attr) {
if (tb->nboot_acl &&
tb->cm_ops->get_boot_acl &&
tb->cm_ops->set_boot_acl)
return attr->mode;
return 0;
}
return attr->mode;
}
static struct attribute_group domain_attr_group = {
.is_visible = domain_attr_is_visible,
.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(&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 bool 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 true;
}
switch (type) {
case TB_CFG_PKG_XDOMAIN_REQ:
case TB_CFG_PKG_XDOMAIN_RESP:
return tb_xdomain_handle_request(tb, type, buf, size);
default:
tb->cm_ops->handle_event(tb, type, buf, size);
}
return true;
}
/**
* 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);
pm_runtime_no_callbacks(&tb->dev);
pm_runtime_set_active(&tb->dev);
pm_runtime_enable(&tb->dev);
pm_runtime_set_autosuspend_delay(&tb->dev, TB_AUTOSUSPEND_DELAY);
pm_runtime_mark_last_busy(&tb->dev);
pm_runtime_use_autosuspend(&tb->dev);
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)
{
return tb->cm_ops->suspend ? tb->cm_ops->suspend(tb) : 0;
}
void tb_domain_complete(struct tb *tb)
{
if (tb->cm_ops->complete)
tb->cm_ops->complete(tb);
}
int tb_domain_runtime_suspend(struct tb *tb)
{
if (tb->cm_ops->runtime_suspend) {
int ret = tb->cm_ops->runtime_suspend(tb);
if (ret)
return ret;
}
tb_ctl_stop(tb->ctl);
return 0;
}
int tb_domain_runtime_resume(struct tb *tb)
{
tb_ctl_start(tb->ctl);
if (tb->cm_ops->runtime_resume) {
int ret = tb->cm_ops->runtime_resume(tb);
if (ret)
return ret;
}
return 0;
}
/**
* 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;
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);
}
/**
* tb_domain_approve_xdomain_paths() - Enable DMA paths for XDomain
* @tb: Domain enabling the DMA paths
* @xd: XDomain DMA paths are created to
*
* Calls connection manager specific method to enable DMA paths to the
* XDomain in question.
*
* Return: 0% in case of success and negative errno otherwise. In
* particular returns %-ENOTSUPP if the connection manager
* implementation does not support XDomains.
*/
int tb_domain_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
{
if (!tb->cm_ops->approve_xdomain_paths)
return -ENOTSUPP;
return tb->cm_ops->approve_xdomain_paths(tb, xd);
}
/**
* tb_domain_disconnect_xdomain_paths() - Disable DMA paths for XDomain
* @tb: Domain disabling the DMA paths
* @xd: XDomain whose DMA paths are disconnected
*
* Calls connection manager specific method to disconnect DMA paths to
* the XDomain in question.
*
* Return: 0% in case of success and negative errno otherwise. In
* particular returns %-ENOTSUPP if the connection manager
* implementation does not support XDomains.
*/
int tb_domain_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
{
if (!tb->cm_ops->disconnect_xdomain_paths)
return -ENOTSUPP;
return tb->cm_ops->disconnect_xdomain_paths(tb, xd);
}
static int disconnect_xdomain(struct device *dev, void *data)
{
struct tb_xdomain *xd;
struct tb *tb = data;
int ret = 0;
xd = tb_to_xdomain(dev);
if (xd && xd->tb == tb)
ret = tb_xdomain_disable_paths(xd);
return ret;
}
/**
* tb_domain_disconnect_all_paths() - Disconnect all paths for the domain
* @tb: Domain whose paths are disconnected
*
* This function can be used to disconnect all paths (PCIe, XDomain) for
* example in preparation for host NVM firmware upgrade. After this is
* called the paths cannot be established without resetting the switch.
*
* Return: %0 in case of success and negative errno otherwise.
*/
int tb_domain_disconnect_all_paths(struct tb *tb)
{
int ret;
ret = tb_domain_disconnect_pcie_paths(tb);
if (ret)
return ret;
return bus_for_each_dev(&tb_bus_type, NULL, tb, disconnect_xdomain);
}
int tb_domain_init(void)
{
int ret;
ret = tb_xdomain_init();
if (ret)
return ret;
ret = bus_register(&tb_bus_type);
if (ret)
tb_xdomain_exit();
return ret;
}
void tb_domain_exit(void)
{
bus_unregister(&tb_bus_type);
ida_destroy(&tb_domain_ida);
tb_switch_exit();
tb_xdomain_exit();
}