On Thu, Feb 1, 2024 at 7:04 AM Randy Dunlap rdunlap@infradead.org wrote:
Hi,
On 1/31/24 09:43, Jens Wiklander wrote:
A number of storage technologies support a specialised hardware partition designed to be resistant to replay attacks. The underlying HW protocols differ but the operations are common. The RPMB partition cannot be accessed via standard block layer, but by a set of specific RPMB commands: WRITE, READ, GET_WRITE_COUNTER, and PROGRAM_KEY. Such a partition provides authenticated and replay protected access, hence suitable as a secure storage.
The initial aim of this patch is to provide a simple RPMB Driver which can be accessed by the optee driver to facilitate early RPMB access to OP-TEE OS (secure OS) during the boot time.
A TEE device driver can claim the RPMB interface, for example, via class_interface_register() or rpmb_dev_find_device(). The RPMB driver provides a callback to route RPMB frames to the RPMB device accessible via rpmb_route_frames().
The detailed operation of implementing the access is left to the TEE device driver itself.
Signed-off-by: Tomas Winkler tomas.winkler@intel.com Signed-off-by: Alex Bennée alex.bennee@linaro.org Signed-off-by: Shyam Saini shyamsaini@linux.microsoft.com Signed-off-by: Jens Wiklander jens.wiklander@linaro.org
MAINTAINERS | 7 ++ drivers/misc/Kconfig | 9 ++ drivers/misc/Makefile | 1 + drivers/misc/rpmb-core.c | 247 +++++++++++++++++++++++++++++++++++++++ include/linux/rpmb.h | 184 +++++++++++++++++++++++++++++ 5 files changed, 448 insertions(+) create mode 100644 drivers/misc/rpmb-core.c create mode 100644 include/linux/rpmb.h
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 4fb291f0bf7c..891aa5763666 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -104,6 +104,15 @@ config PHANTOM If you choose to build module, its name will be phantom. If unsure, say N here.
+config RPMB
tristate "RPMB partition interface"helpUnified RPMB unit interface for RPMB capable devices such as eMMC andUFS. Provides interface for in kernel security controllers to accessin-kernel
RPMB unit.If unsure, select N.config TIFM_CORE tristate "TI Flash Media interface support" depends on PCI
diff --git a/drivers/misc/rpmb-core.c b/drivers/misc/rpmb-core.c new file mode 100644 index 000000000000..a3c289051687 --- /dev/null +++ b/drivers/misc/rpmb-core.c @@ -0,0 +1,247 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- Copyright(c) 2015 - 2019 Intel Corporation. All rights reserved.
- Copyright(c) 2021 - 2024 Linaro Ltd.
- */
+#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/rpmb.h> +#include <linux/slab.h>
+/**
- rpmb_route_frames() - route rpmb frames to rpmb device
- @rdev: rpmb device
- @req: rpmb request frames
- @req_len: length of rpmb request frames in bytes
- @rsp: rpmb response frames
- @rsp_len: length of rpmb response frames in bytes
- @return < 0 on failure
Above needs a colon ':' after @return, although using
- Return:
is preferable IMO.
Thanks, I'll change to "* Return:" instead, everywhere in this patch.
- */
+int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
unsigned int req_len, u8 *rsp, unsigned int rsp_len)+{
+/**
- rpmb_dev_find_device() - return first matching rpmb device
- @data: data for the match function
- @match: the matching function
- @returns a matching rpmb device or NULL on failure
* @returns:or * Returns:
- */
+struct rpmb_dev *rpmb_dev_find_device(const void *data,
const struct rpmb_dev *start,int (*match)(struct device *dev,const void *data))+{
struct device *dev;const struct device *start_dev = NULL;if (start)start_dev = &start->dev;dev = class_find_device(&rpmb_class, start_dev, data, match);return dev ? to_rpmb_dev(dev) : NULL;+}
+/**
- rpmb_dev_unregister() - unregister RPMB partition from the RPMB subsystem
- @rdev: the rpmb device to unregister
- @returns < 0 on failure
Ditto.
- */
+int rpmb_dev_unregister(struct rpmb_dev *rdev) +{
if (!rdev)return -EINVAL;device_del(&rdev->dev);rpmb_dev_put(rdev);return 0;+} +EXPORT_SYMBOL_GPL(rpmb_dev_unregister);
+/**
- rpmb_dev_register - register RPMB partition with the RPMB subsystem
- @dev: storage device of the rpmb device
- @target: RPMB target/region within the physical device
There is no @target function parameter.
You're right, I'll remove it.
- @ops: device specific operations
- While registering the RPMB partition get references to needed resources
- with the @ops->get_resources() callback and extracts needed devices
- information while needed resources are available.
- @returns a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
Ditto for Return syntax.
- */
+struct rpmb_dev *rpmb_dev_register(struct device *dev,
const struct rpmb_ops *ops)+{
struct rpmb_dev *rdev;int id;int ret;if (!dev || !ops || !ops->get_resources ||!ops->put_resources || !ops->route_frames ||!ops->set_dev_info)return ERR_PTR(-EINVAL);rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);if (!rdev)return ERR_PTR(-ENOMEM);mutex_lock(&rpmb_mutex);id = ida_simple_get(&rpmb_ida, 0, 0, GFP_KERNEL);mutex_unlock(&rpmb_mutex);if (id < 0) {ret = id;goto exit;}rdev->ops = ops;rdev->id = id;dev_set_name(&rdev->dev, "rpmb%d", id);rdev->dev.class = &rpmb_class;rdev->dev.parent = dev;ret = ops->set_dev_info(dev, rdev);if (ret)goto exit;ret = device_register(&rdev->dev);if (ret)goto exit;ops->get_resources(rdev->dev.parent);dev_dbg(&rdev->dev, "registered device\n");return rdev;+exit:
if (id >= 0) {mutex_lock(&rpmb_mutex);ida_simple_remove(&rpmb_ida, id);mutex_unlock(&rpmb_mutex);}kfree(rdev);return ERR_PTR(ret);+} +EXPORT_SYMBOL_GPL(rpmb_dev_register);
diff --git a/include/linux/rpmb.h b/include/linux/rpmb.h new file mode 100644 index 000000000000..45073513264a --- /dev/null +++ b/include/linux/rpmb.h @@ -0,0 +1,184 @@ +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */ +/*
- Copyright (C) 2015-2019 Intel Corp. All rights reserved
- Copyright (C) 2021-2022 Linaro Ltd
- */
+#ifndef __RPMB_H__ +#define __RPMB_H__
+#include <linux/types.h> +#include <linux/device.h>
+/**
- struct rpmb_frame - rpmb frame as defined by specs
- @stuff : stuff bytes
- @key_mac : The authentication key or the message authentication
code (MAC) depending on the request/response type.
The MAC will be delivered in the last (or the only)
block of data.
- @data : Data to be written or read by signed access.
- @nonce : Random number generated by the host for the requests
and copied to the response by the RPMB engine.
- @write_counter: Counter value for the total amount of the successful
authenticated data write requests made by the host.
- @addr : Address of the data to be programmed to or read
from the RPMB. Address is the serial number of
the accessed block (half sector 256B).
- @block_count : Number of blocks (half sectors, 256B) requested to be
read/programmed.
- @result : Includes information about the status of the write counter
(valid, expired) and result of the access made to the RPMB.
- @req_resp : Defines the type of request and response to/from the memory.
- */
+struct rpmb_frame {
u8 stuff[196];u8 key_mac[32];u8 data[256];u8 nonce[16];__be32 write_counter;__be16 addr;__be16 block_count;__be16 result;__be16 req_resp;+} __packed;
+#define RPMB_PROGRAM_KEY 0x1 /* Program RPMB Authentication Key */ +#define RPMB_GET_WRITE_COUNTER 0x2 /* Read RPMB write counter */ +#define RPMB_WRITE_DATA 0x3 /* Write data to RPMB partition */ +#define RPMB_READ_DATA 0x4 /* Read data from RPMB partition */ +#define RPMB_RESULT_READ 0x5 /* Read result request (Internal) */
+#define RPMB_REQ2RESP(_OP) ((_OP) << 8) +#define RPMB_RESP2REQ(_OP) ((_OP) >> 8)
+/**
- enum rpmb_op_result - rpmb operation results
- @RPMB_ERR_OK : operation successful
- @RPMB_ERR_GENERAL : general failure
- @RPMB_ERR_AUTH : mac doesn't match or ac calculation failure
- @RPMB_ERR_COUNTER : counter doesn't match or counter increment failure
- @RPMB_ERR_ADDRESS : address out of range or wrong address alignment
- @RPMB_ERR_WRITE : data, counter, or result write failure
- @RPMB_ERR_READ : data, counter, or result read failure
- @RPMB_ERR_NO_KEY : authentication key not yet programmed
- @RPMB_ERR_COUNTER_EXPIRED: counter expired
- */
+enum rpmb_op_result {
RPMB_ERR_OK = 0x0000,RPMB_ERR_GENERAL = 0x0001,RPMB_ERR_AUTH = 0x0002,RPMB_ERR_COUNTER = 0x0003,RPMB_ERR_ADDRESS = 0x0004,RPMB_ERR_WRITE = 0x0005,RPMB_ERR_READ = 0x0006,RPMB_ERR_NO_KEY = 0x0007,RPMB_ERR_COUNTER_EXPIRED = 0x0080+};
+/**
- enum rpmb_type - type of underlaying storage technology
underlying
Thanks
- @RPMB_TYPE_EMMC : emmc (JESD84-B50.1)
- @RPMB_TYPE_UFS : UFS (JESD220)
- @RPMB_TYPE_NVME : NVM Express
- */
+enum rpmb_type {
RPMB_TYPE_EMMC,RPMB_TYPE_UFS,RPMB_TYPE_NVME,+};
+/**
- struct rpmb_dev - device which can support RPMB partition
- @dev : device
- @id : device id;
- @ops : operation exported by rpmb
- @dev_id : unique device identifier read from the hardware
- @dev_id_len : length of unique device identifier
- @reliable_wr_count: number of sectors that can be written in one access
- @capacity : capacity of the device in units of 128K
- */
+struct rpmb_dev {
struct device dev;int id;const struct rpmb_ops *ops;u8 *dev_id;size_t dev_id_len;u16 reliable_wr_count;u16 capacity;+};
+#define to_rpmb_dev(x) container_of((x), struct rpmb_dev, dev)
+/**
- struct rpmb_ops - RPMB ops to be implemented by underlying block device
- @type : block device type
- @get_resources : gets references to needed resources in rpmb_dev_register()
- @put_resources : puts references from resources in rpmb_dev_release()
- @route_frames : routes frames to and from the RPMB device
- @get_dev_info : extracts device info from the RPMB device
set_dev_info ???
Yes.
Thanks, Jens
- */
+struct rpmb_ops {
enum rpmb_type type;void (*get_resources)(struct device *dev);void (*put_resources)(struct device *dev);int (*set_dev_info)(struct device *dev, struct rpmb_dev *rdev);int (*route_frames)(struct device *dev, bool write,u8 *req, unsigned int req_len,u8 *resp, unsigned int resp_len);+};
thanks.
#Randy