// SPDX-License-Identifier: GPL-2.0
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/*
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* Turris Mox rWTM firmware driver
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*
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* Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
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*/
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#include <linux/armada-37xx-rwtm-mailbox.h>
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#include <linux/completion.h>
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#include <linux/debugfs.h>
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#include <linux/dma-mapping.h>
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#include <linux/hw_random.h>
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#include <linux/mailbox_client.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
|
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#define DRIVER_NAME "turris-mox-rwtm"
|
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/*
|
* The macros and constants below come from Turris Mox's rWTM firmware code.
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* This firmware is open source and it's sources can be found at
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* https://gitlab.labs.nic.cz/turris/mox-boot-builder/tree/master/wtmi.
|
*/
|
|
#define MBOX_STS_SUCCESS (0 << 30)
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#define MBOX_STS_FAIL (1 << 30)
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#define MBOX_STS_BADCMD (2 << 30)
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#define MBOX_STS_ERROR(s) ((s) & (3 << 30))
|
#define MBOX_STS_VALUE(s) (((s) >> 10) & 0xfffff)
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#define MBOX_STS_CMD(s) ((s) & 0x3ff)
|
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enum mbox_cmd {
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MBOX_CMD_GET_RANDOM = 1,
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MBOX_CMD_BOARD_INFO = 2,
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MBOX_CMD_ECDSA_PUB_KEY = 3,
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MBOX_CMD_HASH = 4,
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MBOX_CMD_SIGN = 5,
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MBOX_CMD_VERIFY = 6,
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MBOX_CMD_OTP_READ = 7,
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MBOX_CMD_OTP_WRITE = 8,
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};
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struct mox_kobject;
|
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struct mox_rwtm {
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struct device *dev;
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struct mbox_client mbox_client;
|
struct mbox_chan *mbox;
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struct mox_kobject *kobj;
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struct hwrng hwrng;
|
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struct armada_37xx_rwtm_rx_msg reply;
|
|
void *buf;
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dma_addr_t buf_phys;
|
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struct mutex busy;
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struct completion cmd_done;
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/* board information */
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int has_board_info;
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u64 serial_number;
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int board_version, ram_size;
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u8 mac_address1[6], mac_address2[6];
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/* public key burned in eFuse */
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int has_pubkey;
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u8 pubkey[135];
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#ifdef CONFIG_DEBUG_FS
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/*
|
* Signature process. This is currently done via debugfs, because it
|
* does not conform to the sysfs standard "one file per attribute".
|
* It should be rewritten via crypto API once akcipher API is available
|
* from userspace.
|
*/
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struct dentry *debugfs_root;
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u32 last_sig[34];
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int last_sig_done;
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#endif
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};
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struct mox_kobject {
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struct kobject kobj;
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struct mox_rwtm *rwtm;
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};
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static inline struct kobject *rwtm_to_kobj(struct mox_rwtm *rwtm)
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{
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return &rwtm->kobj->kobj;
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}
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static inline struct mox_rwtm *to_rwtm(struct kobject *kobj)
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{
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return container_of(kobj, struct mox_kobject, kobj)->rwtm;
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}
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static void mox_kobj_release(struct kobject *kobj)
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{
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kfree(to_rwtm(kobj)->kobj);
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}
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static struct kobj_type mox_kobj_ktype = {
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.release = mox_kobj_release,
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.sysfs_ops = &kobj_sysfs_ops,
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};
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static int mox_kobj_create(struct mox_rwtm *rwtm)
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{
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rwtm->kobj = kzalloc(sizeof(*rwtm->kobj), GFP_KERNEL);
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if (!rwtm->kobj)
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return -ENOMEM;
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kobject_init(rwtm_to_kobj(rwtm), &mox_kobj_ktype);
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if (kobject_add(rwtm_to_kobj(rwtm), firmware_kobj, "turris-mox-rwtm")) {
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kobject_put(rwtm_to_kobj(rwtm));
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return -ENXIO;
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}
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rwtm->kobj->rwtm = rwtm;
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return 0;
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}
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#define MOX_ATTR_RO(name, format, cat) \
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static ssize_t \
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name##_show(struct kobject *kobj, struct kobj_attribute *a, \
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char *buf) \
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{ \
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struct mox_rwtm *rwtm = to_rwtm(kobj); \
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if (!rwtm->has_##cat) \
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return -ENODATA; \
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return sprintf(buf, format, rwtm->name); \
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} \
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static struct kobj_attribute mox_attr_##name = __ATTR_RO(name)
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MOX_ATTR_RO(serial_number, "%016llX\n", board_info);
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MOX_ATTR_RO(board_version, "%i\n", board_info);
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MOX_ATTR_RO(ram_size, "%i\n", board_info);
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MOX_ATTR_RO(mac_address1, "%pM\n", board_info);
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MOX_ATTR_RO(mac_address2, "%pM\n", board_info);
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MOX_ATTR_RO(pubkey, "%s\n", pubkey);
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static int mox_get_status(enum mbox_cmd cmd, u32 retval)
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{
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if (MBOX_STS_CMD(retval) != cmd)
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return -EIO;
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else if (MBOX_STS_ERROR(retval) == MBOX_STS_FAIL)
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return -(int)MBOX_STS_VALUE(retval);
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else if (MBOX_STS_ERROR(retval) == MBOX_STS_BADCMD)
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return -ENOSYS;
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else if (MBOX_STS_ERROR(retval) != MBOX_STS_SUCCESS)
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return -EIO;
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else
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return MBOX_STS_VALUE(retval);
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}
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static const struct attribute *mox_rwtm_attrs[] = {
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&mox_attr_serial_number.attr,
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&mox_attr_board_version.attr,
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&mox_attr_ram_size.attr,
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&mox_attr_mac_address1.attr,
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&mox_attr_mac_address2.attr,
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&mox_attr_pubkey.attr,
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NULL
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};
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static void mox_rwtm_rx_callback(struct mbox_client *cl, void *data)
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{
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struct mox_rwtm *rwtm = dev_get_drvdata(cl->dev);
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struct armada_37xx_rwtm_rx_msg *msg = data;
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rwtm->reply = *msg;
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complete(&rwtm->cmd_done);
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}
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static void reply_to_mac_addr(u8 *mac, u32 t1, u32 t2)
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{
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mac[0] = t1 >> 8;
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mac[1] = t1;
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mac[2] = t2 >> 24;
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mac[3] = t2 >> 16;
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mac[4] = t2 >> 8;
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mac[5] = t2;
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}
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static int mox_get_board_info(struct mox_rwtm *rwtm)
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{
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struct armada_37xx_rwtm_tx_msg msg;
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struct armada_37xx_rwtm_rx_msg *reply = &rwtm->reply;
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int ret;
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msg.command = MBOX_CMD_BOARD_INFO;
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ret = mbox_send_message(rwtm->mbox, &msg);
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if (ret < 0)
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return ret;
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ret = wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2);
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if (ret < 0)
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return ret;
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ret = mox_get_status(MBOX_CMD_BOARD_INFO, reply->retval);
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if (ret == -ENODATA) {
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dev_warn(rwtm->dev,
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"Board does not have manufacturing information burned!\n");
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} else if (ret == -ENOSYS) {
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dev_notice(rwtm->dev,
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"Firmware does not support the BOARD_INFO command\n");
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} else if (ret < 0) {
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return ret;
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} else {
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rwtm->serial_number = reply->status[1];
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rwtm->serial_number <<= 32;
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rwtm->serial_number |= reply->status[0];
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rwtm->board_version = reply->status[2];
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rwtm->ram_size = reply->status[3];
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reply_to_mac_addr(rwtm->mac_address1, reply->status[4],
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reply->status[5]);
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reply_to_mac_addr(rwtm->mac_address2, reply->status[6],
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reply->status[7]);
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rwtm->has_board_info = 1;
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pr_info("Turris Mox serial number %016llX\n",
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rwtm->serial_number);
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pr_info(" board version %i\n", rwtm->board_version);
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pr_info(" burned RAM size %i MiB\n", rwtm->ram_size);
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}
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msg.command = MBOX_CMD_ECDSA_PUB_KEY;
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ret = mbox_send_message(rwtm->mbox, &msg);
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if (ret < 0)
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return ret;
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ret = wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2);
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if (ret < 0)
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return ret;
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ret = mox_get_status(MBOX_CMD_ECDSA_PUB_KEY, reply->retval);
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if (ret == -ENODATA) {
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dev_warn(rwtm->dev, "Board has no public key burned!\n");
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} else if (ret == -ENOSYS) {
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dev_notice(rwtm->dev,
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"Firmware does not support the ECDSA_PUB_KEY command\n");
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} else if (ret < 0) {
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return ret;
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} else {
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u32 *s = reply->status;
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rwtm->has_pubkey = 1;
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sprintf(rwtm->pubkey,
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"%06x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x",
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ret, s[0], s[1], s[2], s[3], s[4], s[5], s[6], s[7],
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s[8], s[9], s[10], s[11], s[12], s[13], s[14], s[15]);
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}
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return 0;
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}
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static int check_get_random_support(struct mox_rwtm *rwtm)
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{
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struct armada_37xx_rwtm_tx_msg msg;
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int ret;
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msg.command = MBOX_CMD_GET_RANDOM;
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msg.args[0] = 1;
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msg.args[1] = rwtm->buf_phys;
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msg.args[2] = 4;
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ret = mbox_send_message(rwtm->mbox, &msg);
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if (ret < 0)
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return ret;
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ret = wait_for_completion_timeout(&rwtm->cmd_done, HZ / 2);
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if (ret < 0)
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return ret;
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return mox_get_status(MBOX_CMD_GET_RANDOM, rwtm->reply.retval);
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}
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static int mox_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
|
{
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struct mox_rwtm *rwtm = (struct mox_rwtm *) rng->priv;
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struct armada_37xx_rwtm_tx_msg msg;
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int ret;
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if (max > 4096)
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max = 4096;
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msg.command = MBOX_CMD_GET_RANDOM;
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msg.args[0] = 1;
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msg.args[1] = rwtm->buf_phys;
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msg.args[2] = (max + 3) & ~3;
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if (!wait) {
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if (!mutex_trylock(&rwtm->busy))
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return -EBUSY;
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} else {
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mutex_lock(&rwtm->busy);
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}
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ret = mbox_send_message(rwtm->mbox, &msg);
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if (ret < 0)
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goto unlock_mutex;
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ret = wait_for_completion_interruptible(&rwtm->cmd_done);
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if (ret < 0)
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goto unlock_mutex;
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ret = mox_get_status(MBOX_CMD_GET_RANDOM, rwtm->reply.retval);
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if (ret < 0)
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goto unlock_mutex;
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memcpy(data, rwtm->buf, max);
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ret = max;
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unlock_mutex:
|
mutex_unlock(&rwtm->busy);
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return ret;
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}
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#ifdef CONFIG_DEBUG_FS
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static int rwtm_debug_open(struct inode *inode, struct file *file)
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{
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file->private_data = inode->i_private;
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|
return nonseekable_open(inode, file);
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}
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static ssize_t do_sign_read(struct file *file, char __user *buf, size_t len,
|
loff_t *ppos)
|
{
|
struct mox_rwtm *rwtm = file->private_data;
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ssize_t ret;
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/* only allow one read, of 136 bytes, from position 0 */
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if (*ppos != 0)
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return 0;
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if (len < 136)
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return -EINVAL;
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if (!rwtm->last_sig_done)
|
return -ENODATA;
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|
/* 2 arrays of 17 32-bit words are 136 bytes */
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ret = simple_read_from_buffer(buf, len, ppos, rwtm->last_sig, 136);
|
rwtm->last_sig_done = 0;
|
|
return ret;
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}
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|
static ssize_t do_sign_write(struct file *file, const char __user *buf,
|
size_t len, loff_t *ppos)
|
{
|
struct mox_rwtm *rwtm = file->private_data;
|
struct armada_37xx_rwtm_rx_msg *reply = &rwtm->reply;
|
struct armada_37xx_rwtm_tx_msg msg;
|
loff_t dummy = 0;
|
ssize_t ret;
|
|
/* the input is a SHA-512 hash, so exactly 64 bytes have to be read */
|
if (len != 64)
|
return -EINVAL;
|
|
/* if last result is not zero user has not read that information yet */
|
if (rwtm->last_sig_done)
|
return -EBUSY;
|
|
if (!mutex_trylock(&rwtm->busy))
|
return -EBUSY;
|
|
/*
|
* Here we have to send:
|
* 1. Address of the input to sign.
|
* The input is an array of 17 32-bit words, the first (most
|
* significat) is 0, the rest 16 words are copied from the SHA-512
|
* hash given by the user and converted from BE to LE.
|
* 2. Address of the buffer where ECDSA signature value R shall be
|
* stored by the rWTM firmware.
|
* 3. Address of the buffer where ECDSA signature value S shall be
|
* stored by the rWTM firmware.
|
*/
|
memset(rwtm->buf, 0, 4);
|
ret = simple_write_to_buffer(rwtm->buf + 4, 64, &dummy, buf, len);
|
if (ret < 0)
|
goto unlock_mutex;
|
be32_to_cpu_array(rwtm->buf, rwtm->buf, 17);
|
|
msg.command = MBOX_CMD_SIGN;
|
msg.args[0] = 1;
|
msg.args[1] = rwtm->buf_phys;
|
msg.args[2] = rwtm->buf_phys + 68;
|
msg.args[3] = rwtm->buf_phys + 2 * 68;
|
ret = mbox_send_message(rwtm->mbox, &msg);
|
if (ret < 0)
|
goto unlock_mutex;
|
|
ret = wait_for_completion_interruptible(&rwtm->cmd_done);
|
if (ret < 0)
|
goto unlock_mutex;
|
|
ret = MBOX_STS_VALUE(reply->retval);
|
if (MBOX_STS_ERROR(reply->retval) != MBOX_STS_SUCCESS)
|
goto unlock_mutex;
|
|
/*
|
* Here we read the R and S values of the ECDSA signature
|
* computed by the rWTM firmware and convert their words from
|
* LE to BE.
|
*/
|
memcpy(rwtm->last_sig, rwtm->buf + 68, 136);
|
cpu_to_be32_array(rwtm->last_sig, rwtm->last_sig, 34);
|
rwtm->last_sig_done = 1;
|
|
mutex_unlock(&rwtm->busy);
|
return len;
|
unlock_mutex:
|
mutex_unlock(&rwtm->busy);
|
return ret;
|
}
|
|
static const struct file_operations do_sign_fops = {
|
.owner = THIS_MODULE,
|
.open = rwtm_debug_open,
|
.read = do_sign_read,
|
.write = do_sign_write,
|
.llseek = no_llseek,
|
};
|
|
static int rwtm_register_debugfs(struct mox_rwtm *rwtm)
|
{
|
struct dentry *root, *entry;
|
|
root = debugfs_create_dir("turris-mox-rwtm", NULL);
|
|
if (IS_ERR(root))
|
return PTR_ERR(root);
|
|
entry = debugfs_create_file_unsafe("do_sign", 0600, root, rwtm,
|
&do_sign_fops);
|
if (IS_ERR(entry))
|
goto err_remove;
|
|
rwtm->debugfs_root = root;
|
|
return 0;
|
err_remove:
|
debugfs_remove_recursive(root);
|
return PTR_ERR(entry);
|
}
|
|
static void rwtm_unregister_debugfs(struct mox_rwtm *rwtm)
|
{
|
debugfs_remove_recursive(rwtm->debugfs_root);
|
}
|
#else
|
static inline int rwtm_register_debugfs(struct mox_rwtm *rwtm)
|
{
|
return 0;
|
}
|
|
static inline void rwtm_unregister_debugfs(struct mox_rwtm *rwtm)
|
{
|
}
|
#endif
|
|
static int turris_mox_rwtm_probe(struct platform_device *pdev)
|
{
|
struct mox_rwtm *rwtm;
|
struct device *dev = &pdev->dev;
|
int ret;
|
|
rwtm = devm_kzalloc(dev, sizeof(*rwtm), GFP_KERNEL);
|
if (!rwtm)
|
return -ENOMEM;
|
|
rwtm->dev = dev;
|
rwtm->buf = dmam_alloc_coherent(dev, PAGE_SIZE, &rwtm->buf_phys,
|
GFP_KERNEL);
|
if (!rwtm->buf)
|
return -ENOMEM;
|
|
ret = mox_kobj_create(rwtm);
|
if (ret < 0) {
|
dev_err(dev, "Cannot create turris-mox-rwtm kobject!\n");
|
return ret;
|
}
|
|
ret = sysfs_create_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs);
|
if (ret < 0) {
|
dev_err(dev, "Cannot create sysfs files!\n");
|
goto put_kobj;
|
}
|
|
platform_set_drvdata(pdev, rwtm);
|
|
mutex_init(&rwtm->busy);
|
|
rwtm->mbox_client.dev = dev;
|
rwtm->mbox_client.rx_callback = mox_rwtm_rx_callback;
|
|
rwtm->mbox = mbox_request_channel(&rwtm->mbox_client, 0);
|
if (IS_ERR(rwtm->mbox)) {
|
ret = PTR_ERR(rwtm->mbox);
|
if (ret != -EPROBE_DEFER)
|
dev_err(dev, "Cannot request mailbox channel: %i\n",
|
ret);
|
goto remove_files;
|
}
|
|
init_completion(&rwtm->cmd_done);
|
|
ret = mox_get_board_info(rwtm);
|
if (ret < 0)
|
dev_warn(dev, "Cannot read board information: %i\n", ret);
|
|
ret = check_get_random_support(rwtm);
|
if (ret < 0) {
|
dev_notice(dev,
|
"Firmware does not support the GET_RANDOM command\n");
|
goto free_channel;
|
}
|
|
rwtm->hwrng.name = DRIVER_NAME "_hwrng";
|
rwtm->hwrng.read = mox_hwrng_read;
|
rwtm->hwrng.priv = (unsigned long) rwtm;
|
rwtm->hwrng.quality = 1024;
|
|
ret = devm_hwrng_register(dev, &rwtm->hwrng);
|
if (ret < 0) {
|
dev_err(dev, "Cannot register HWRNG: %i\n", ret);
|
goto free_channel;
|
}
|
|
ret = rwtm_register_debugfs(rwtm);
|
if (ret < 0) {
|
dev_err(dev, "Failed creating debugfs entries: %i\n", ret);
|
goto free_channel;
|
}
|
|
dev_info(dev, "HWRNG successfully registered\n");
|
|
return 0;
|
|
free_channel:
|
mbox_free_channel(rwtm->mbox);
|
remove_files:
|
sysfs_remove_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs);
|
put_kobj:
|
kobject_put(rwtm_to_kobj(rwtm));
|
return ret;
|
}
|
|
static int turris_mox_rwtm_remove(struct platform_device *pdev)
|
{
|
struct mox_rwtm *rwtm = platform_get_drvdata(pdev);
|
|
rwtm_unregister_debugfs(rwtm);
|
sysfs_remove_files(rwtm_to_kobj(rwtm), mox_rwtm_attrs);
|
kobject_put(rwtm_to_kobj(rwtm));
|
mbox_free_channel(rwtm->mbox);
|
|
return 0;
|
}
|
|
static const struct of_device_id turris_mox_rwtm_match[] = {
|
{ .compatible = "cznic,turris-mox-rwtm", },
|
{ .compatible = "marvell,armada-3700-rwtm-firmware", },
|
{ },
|
};
|
|
MODULE_DEVICE_TABLE(of, turris_mox_rwtm_match);
|
|
static struct platform_driver turris_mox_rwtm_driver = {
|
.probe = turris_mox_rwtm_probe,
|
.remove = turris_mox_rwtm_remove,
|
.driver = {
|
.name = DRIVER_NAME,
|
.of_match_table = turris_mox_rwtm_match,
|
},
|
};
|
module_platform_driver(turris_mox_rwtm_driver);
|
|
MODULE_LICENSE("GPL v2");
|
MODULE_DESCRIPTION("Turris Mox rWTM firmware driver");
|
MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
|
