On Fri, Mar 22, 2024 at 5:26 PM Ulf Hansson ulf.hansson@linaro.org wrote:

On Tue, 27 Feb 2024 at 16:31, Jens Wiklander jens.wiklander@linaro.org 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 interface 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 rpmb_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 | 10 ++ drivers/misc/Makefile | 1 + drivers/misc/rpmb-core.c | 258 +++++++++++++++++++++++++++++++++++++++ include/linux/rpmb.h | 195 +++++++++++++++++++++++++++++ 5 files changed, 471 insertions(+) create mode 100644 drivers/misc/rpmb-core.c create mode 100644 include/linux/rpmb.h

diff --git a/MAINTAINERS b/MAINTAINERS index 8999497011a2..e83152c42499 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19012,6 +19012,13 @@ T: git git://linuxtv.org/media_tree.git F: Documentation/devicetree/bindings/media/allwinner,sun8i-a83t-de2-rotate.yaml F: drivers/media/platform/sunxi/sun8i-rotate/

+RPMB SUBSYSTEM +M: Jens Wiklander jens.wiklander@linaro.org +L: linux-kernel@vger.kernel.org +S: Supported +F: drivers/misc/rpmb-core.c +F: include/linux/rpmb.h

RPMSG TTY DRIVER M: Arnaud Pouliquen arnaud.pouliquen@foss.st.com L: linux-remoteproc@vger.kernel.org diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 4fb291f0bf7c..dbff9e8c3a03 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -104,6 +104,16 @@ config PHANTOM If you choose to build module, its name will be phantom. If unsure, say N here.

+config RPMB

•   tristate "RPMB partition interface"
  

•   depends on MMC
  

•   help
  

•     Unified RPMB unit interface for RPMB capable devices such as eMMC and
  

•     UFS. Provides interface for in-kernel security controllers to access
  

•     RPMB unit.
  

•     If unsure, select N.
  

config TIFM_CORE tristate "TI Flash Media interface support" depends on PCI diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index ea6ea5bbbc9c..8af058ad1df4 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_LKDTM) += lkdtm/ obj-$(CONFIG_TIFM_CORE) += tifm_core.o obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o obj-$(CONFIG_PHANTOM) += phantom.o +obj-$(CONFIG_RPMB) += rpmb-core.o obj-$(CONFIG_QCOM_COINCELL) += qcom-coincell.o obj-$(CONFIG_QCOM_FASTRPC) += fastrpc.o obj-$(CONFIG_SENSORS_BH1770) += bh1770glc.o diff --git a/drivers/misc/rpmb-core.c b/drivers/misc/rpmb-core.c new file mode 100644 index 000000000000..e0003b039e9f --- /dev/null +++ b/drivers/misc/rpmb-core.c @@ -0,0 +1,258 @@ +// 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>

+static struct list_head rpmb_dev_list; +static struct list_head rpmb_intf_list; +static DEFINE_MUTEX(rpmb_mutex);

+/**

• • rpmb_dev_get() - increase rpmb device ref counter
• • @rdev: rpmb device
• */

+struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev) +{

•   if (rdev)
  

•           get_device(rdev->parent_dev);
  

•   return rdev;
  

+} +EXPORT_SYMBOL_GPL(rpmb_dev_get);

As rpmb_dev_find_device() already bumps the reference count by calling rpmb_dev_get(), why does this need to be exported and called by the tee driver in patch3, too?

Would it not be sufficient to export only rpmb_dev_put()?

Ahh, I realized now that when calling ->add_rdev() callback, the mutex is being held without first increasing the reference count. Hmm, I don't know what makes the best sense here.

rpmb_dev_get() is needed in another place in the OP-TEE driver too, I'll get to that below.

...

+/**

• • rpmb_dev_put() - decrease rpmb device ref counter
• • @rdev: rpmb device
• */

+void rpmb_dev_put(struct rpmb_dev *rdev) +{

•   if (rdev)
  

•           put_device(rdev->parent_dev);
  

+} +EXPORT_SYMBOL_GPL(rpmb_dev_put);

+/**

• • 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
• • Returns: < 0 on failure
• */

+int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,

•                 unsigned int req_len, u8 *rsp, unsigned int rsp_len)
  

+{

•   struct rpmb_frame *frm = (struct rpmb_frame *)req;
  

•   u16 req_type;
  

•   bool write;
  

•   if (!req || req_len < sizeof(*frm) || !rsp || !rsp_len)
  

•           return -EINVAL;
  

•   req_type = be16_to_cpu(frm->req_resp);
  

•   switch (req_type) {
  

•   case RPMB_PROGRAM_KEY:
  

•           if (req_len != sizeof(struct rpmb_frame) ||
  

•               rsp_len != sizeof(struct rpmb_frame))
  

•                   return -EINVAL;
  

•           write = true;
  

•           break;
  

•   case RPMB_GET_WRITE_COUNTER:
  

•           if (req_len != sizeof(struct rpmb_frame) ||
  

•               rsp_len != sizeof(struct rpmb_frame))
  

•                   return -EINVAL;
  

•           write = false;
  

•           break;
  

•   case RPMB_WRITE_DATA:
  

•           if (req_len % sizeof(struct rpmb_frame) ||
  

•               rsp_len != sizeof(struct rpmb_frame))
  

•                   return -EINVAL;
  

•           write = true;
  

•           break;
  

•   case RPMB_READ_DATA:
  

•           if (req_len != sizeof(struct rpmb_frame) ||
  

•               rsp_len % sizeof(struct rpmb_frame))
  

•                   return -EINVAL;
  

•           write = false;
  

•           break;
  

•   default:
  

•           return -EINVAL;
  

•   }
  

•   return rdev->ops->route_frames(rdev->parent_dev, write,
  

•                                  req, req_len, rsp, rsp_len);
  

+} +EXPORT_SYMBOL_GPL(rpmb_route_frames);

+/**

• • rpmb_dev_find_device() - return first matching rpmb device
• • @data: data for the match function
• • @match: the matching function

There are a couple of missing parameters that should be described here.

Moreover, I think it's important to clarify that it's the caller's responsibility to call rpmb_dev_put() on the returned rpmb_dev, when it's ready with it.

I'll update.

...

• • Returns: a matching rpmb device or NULL on failure
• */

+struct rpmb_dev *rpmb_dev_find_device(const void *data,

•                                 const struct rpmb_dev *start,
  

•                                 int (*match)(struct rpmb_dev *rdev,
  

•                                              const void *data))
  

+{

•   struct rpmb_dev *rdev;
  

•   struct list_head *pos;
  

•   mutex_lock(&rpmb_mutex);
  

•   if (start)
  

•           pos = start->list_node.next;
  

•   else
  

•           pos = rpmb_dev_list.next;
  

•   while (pos != &rpmb_dev_list) {
  

•           rdev = container_of(pos, struct rpmb_dev, list_node);
  

•           if (match(rdev, data)) {
  

•                   rpmb_dev_get(rdev);
  

•                   goto out;
  

•           }
  

•           pos = pos->next;
  

•   }
  

•   rdev = NULL;
  

+out:

•   mutex_unlock(&rpmb_mutex);
  

•   return rdev;
  

+}

+/**

• • rpmb_dev_unregister() - unregister RPMB partition from the RPMB subsystem
• • @rdev: the rpmb device to unregister

It would be nice to clarify in the function description for when this should be called. Especially from the data-lifecycle point of view.

OK, I'll update.

...

• • Returns: < 0 on failure
• */

+int rpmb_dev_unregister(struct rpmb_dev *rdev) +{

•   if (!rdev)
  

•           return -EINVAL;
  

•   mutex_lock(&rpmb_mutex);
  

•   list_del(&rdev->list_node);
  

•   mutex_unlock(&rpmb_mutex);
  

•   kfree(rdev->dev_id);
  

•   kfree(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
• • @ops: device specific operations
• • While registering the RPMB partition extract needed device information
• • while needed resources are available.
• • Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
• */

+struct rpmb_dev *rpmb_dev_register(struct device *dev,

•                              const struct rpmb_ops *ops)
  

+{

•   struct rpmb_dev *rdev;
  

•   struct rpmb_interface *intf;
  

•   int ret;
  

•   if (!dev || !ops || !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);
  

•   list_add_tail(&rdev->list_node, &rpmb_dev_list);
  

•   mutex_unlock(&rpmb_mutex);
  

It does not look safe to add an rpmb_dev to the rpmb_dev_list, before it has been completely initialized. The consumer of it may fetch it and try use it before it's initialized.

You're right, I'll move the registration to the end of mmc_blk_probe().

...

•   rdev->ops = ops;
  

•   rdev->parent_dev = dev;
  

•   ret = ops->set_dev_info(dev, rdev);
  

Rather than using a callback to initialize the rpmb_dev, I would suggest (and prefer) to let the corresponding data be provided as an in-parameter to rpmb_dev_register() instead.

OK

...

•   if (ret)
  

•           goto exit;
  

•   dev_dbg(rdev->parent_dev, "registered device\n");
  

•   mutex_lock(&rpmb_mutex);
  

•   list_for_each_entry(intf, &rpmb_intf_list, list_node)
  

•           if (intf->add_rdev)
  

•                   intf->add_rdev(intf, rdev);
  

Rather than implementing our own specific notification mechanism, we could make use of a "blocking_notifier" (include/linux/notifier.h) instead.

Good idea, I'll use that.

Moreover, it looks like we are lacking a way to inform the consumer driver that an rpmb_dev is being removed. Or maybe that isn't needed, as the reference counting manages that for us?

Yes, the reference counting is managing this.

...

•   mutex_unlock(&rpmb_mutex);
  

•   return rdev;
  

+exit:

•   mutex_lock(&rpmb_mutex);
  

•   list_del(&rdev->list_node);
  

•   mutex_unlock(&rpmb_mutex);
  

•   kfree(rdev);
  

•   return ERR_PTR(ret);
  

+} +EXPORT_SYMBOL_GPL(rpmb_dev_register);

+/**

• • rpmb_interface_register() - register for new device notifications
• • @intf : pointer to interface struct with a notification callback
• */

+void rpmb_interface_register(struct rpmb_interface *intf) +{

•   struct rpmb_dev *rdev;
  

•   mutex_lock(&rpmb_mutex);
  

•   list_add_tail(&intf->list_node, &rpmb_intf_list);
  

•   if (intf->add_rdev)
  

Is there any reason to allow the ->add_rdev() callback to be optional?

No, I'll fix.

...

•           list_for_each_entry(rdev, &rpmb_dev_list, list_node)
  

•                   intf->add_rdev(intf, rdev);
  

What if ->add_rdev() are happy to use one of the rpmb_dev, then we will still continue to iterate over the list. Should we use a return code to indicate if we should continue or not?

I'm switching to "blocking_notifier".

...

•   mutex_unlock(&rpmb_mutex);
  

+} +EXPORT_SYMBOL_GPL(rpmb_interface_register);

+/**

• • rpmb_interface_unregister() - unregister from new device notifications
• • @intf : pointer to previously registered interface struct
• */

+void rpmb_interface_unregister(struct rpmb_interface *intf) +{

•   mutex_lock(&rpmb_mutex);
  

•   list_del(&intf->list_node);
  

•   mutex_unlock(&rpmb_mutex);
  

+} +EXPORT_SYMBOL_GPL(rpmb_interface_unregister);

+static int __init rpmb_init(void) +{

•   INIT_LIST_HEAD(&rpmb_dev_list);
  

•   INIT_LIST_HEAD(&rpmb_intf_list);
  

•   return 0;
  

+}

+static void __exit rpmb_exit(void) +{

•   mutex_destroy(&rpmb_mutex);
  

+}

+subsys_initcall(rpmb_init); +module_exit(rpmb_exit);

+MODULE_AUTHOR("Jens Wiklander jens.wiklander@linaro.org"); +MODULE_DESCRIPTION("RPMB class"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/rpmb.h b/include/linux/rpmb.h new file mode 100644 index 000000000000..c4b13dad10c4 --- /dev/null +++ b/include/linux/rpmb.h @@ -0,0 +1,195 @@ +/* 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;

I haven't looked at the NVME or the UFS spec in detail. Although, I assume the above frame makes sense for those types of interfaces/protocols too?

This is MMC-specific as we learned in the mail thread. I'll move this into the MMC-specific code.

...

+#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 underlying storage technology
• • @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
• • @parent_dev : parent device
• • @list_node : linked list node
• • @ops : operation exported by rpmb
• • @dev_id : unique device identifier read from the hardware

This part puzzled me a bit, when I realized that they are used as an input to derive the authentication-data.

For eMMC (as shown in patch2), we have chosen to use the CID register data, which makes perfect sense to me. However, I think it's important to clarify what this field is being used for, here in the description too.

Good point, I'll add that.

...

• • @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 *parent_dev;
  

•   struct list_head list_node;
  

•   const struct rpmb_ops *ops;
  

•   u8 *dev_id;
  

•   size_t dev_id_len;
  

•   u16 reliable_wr_count;
  

•   u16 capacity;
  

+};

+/**

• • struct rpmb_ops - RPMB ops to be implemented by underlying block device
• • @type : block device type
• • @route_frames : routes frames to and from the RPMB device
• • @set_dev_info : extracts device info from the RPMB device
• */

+struct rpmb_ops {

•   enum rpmb_type type;
  

I would keep this in the rpmb_dev instead, as it's not really a callback (ops).

...

•   int (*set_dev_info)(struct device *dev, struct rpmb_dev *rdev);
  

As I suggested earlier, we should be able to drop the above callback. That said, it looks like we end up with only one callback left, so maybe just put that in the struct rpmb_dev instead?

OK

Thanks, Jens

...

•   int (*route_frames)(struct device *dev, bool write,
  

•                       u8 *req, unsigned int req_len,
  

•                       u8 *resp, unsigned int resp_len);
  

+};

+/**

• • struct rpmb_interface - subscribe to new RPMB devices
• • @list_node : linked list node
• • @add_rdev : notifies that a new RPMB device has been found
• */

+struct rpmb_interface {

•   struct list_head list_node;
  

•   void (*add_rdev)(struct rpmb_interface *intf, struct rpmb_dev *rdev);
  

+};

+#if IS_ENABLED(CONFIG_RPMB) +struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev); +void rpmb_dev_put(struct rpmb_dev *rdev); +struct rpmb_dev *rpmb_dev_find_device(const void *data,

•                                 const struct rpmb_dev *start,
  

•                                 int (*match)(struct rpmb_dev *rdev,
  

•                                              const void *data));
  

+struct rpmb_dev *rpmb_dev_register(struct device *dev,

•                              const struct rpmb_ops *ops);
  

+int rpmb_dev_unregister(struct rpmb_dev *rdev);

+int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,

•                 unsigned int req_len, u8 *resp, unsigned int resp_len);
  

+void rpmb_interface_register(struct rpmb_interface *intf); +void rpmb_interface_unregister(struct rpmb_interface *intf); +#else +static inline struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev) +{

•   return NULL;
  

+}

+static inline void rpmb_dev_put(struct rpmb_dev *rdev) { }

+static inline struct rpmb_dev * +rpmb_dev_find_device(const void *data, const struct rpmb_dev *start,

•                int (*match)(struct rpmb_dev *rdev, const void *data))
  

+{

•   return NULL;
  

+}

+static inline struct rpmb_dev * +rpmb_dev_register(struct device *dev, const struct rpmb_ops *ops) +{

•   return NULL;
  

+}

+static inline int rpmb_dev_unregister(struct rpmb_dev *dev) +{

•   return 0;
  

+}

+static inline int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,

•                               unsigned int req_len, u8 *resp,
  

•                               unsigned int resp_len)
  

+{

•   return -EOPNOTSUPP;
  

+}

+static inline void rpmb_interface_register(struct rpmb_interface *intf) { } +static inline void rpmb_interface_unregister(struct rpmb_interface *intf) { } +#endif /* CONFIG_RPMB */

+#endif /* __RPMB_H__ */

2.34.1

Kind regards Uffe

On Fri, Mar 1, 2024 at 11:28 AM Sumit Garg sumit.garg@linaro.org wrote:

Hi Jens,

On Tue, 27 Feb 2024 at 21:01, Jens Wiklander jens.wiklander@linaro.org wrote:

...

Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and use an RPMB device via the RPBM subsystem instead of passing the RPMB

s/RPBM/RPMB/

Here are other places too in this patch-set.

...

frames via tee-supplicant in user space. A fallback mechanism is kept to route RPMB frames via tee-supplicant if the RPMB subsystem isn't available.

The OP-TEE RPC ABI is extended to support iterating over all RPMB devices until one is found with the expected RPMB key already programmed.

I would appreciate it if you could add a link to OP-TEE OS changes in the cover-letter although I have found them here [1].

[1] https://github.com/jenswi-linaro/optee_os/commits/rpmb_probe/

OK, I'll add a link in the coverletter of the next patch set.

...

Signed-off-by: Jens Wiklander jens.wiklander@linaro.org

drivers/tee/optee/core.c | 55 +++++++ drivers/tee/optee/ffa_abi.c | 7 + drivers/tee/optee/optee_private.h | 16 ++ drivers/tee/optee/optee_rpc_cmd.h | 35 +++++ drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++ drivers/tee/optee/smc_abi.c | 6 + 6 files changed, 352 insertions(+)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 3aed554bc8d8..6b32d3e7865b 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -11,6 +11,7 @@ #include <linux/io.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/rpmb.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/tee_drv.h> @@ -80,6 +81,57 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm, shm->pages = NULL; }

+static void optee_rpmb_scan(struct work_struct *work) +{

•   struct optee *optee = container_of(work, struct optee, scan_rpmb_work);
  

•   bool scan_done = false;
  

•   u32 res;
  

•   do {
  

•           mutex_lock(&optee->rpmb_dev_mutex);
  

•           /* No need to rescan if we haven't started scanning yet */
  

•           optee->rpmb_dev_request_rescan = false;
  

•           mutex_unlock(&optee->rpmb_dev_mutex);
  

•           res = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
  

•           if (res && res != TEE_ERROR_STORAGE_NOT_AVAILABLE)
  

I suppose this hasn't been tested for a negative case since optee_enumerate_devices() won't return this error code (see [2]). However, I would prefer to use GP Client error code: TEEC_ERROR_ITEM_NOT_FOUND here instead.

[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/driv...

I prefer TEE_ERROR_STORAGE_NOT_AVAILABLE since that's the code GP says a TA should get when storage is unavailable. TEEC_ERROR_ITEM_NOT_FOUND is less specific. Anyway, I'll need to translate the code in get_devices().

...

•                   pr_info("Scanning for RPMB device: res %#x\n", res);
  

•           mutex_lock(&optee->rpmb_dev_mutex);
  

•           /*
  

•            * If another RPMB device came online while scanning, scan one
  

•            * more time, unless we have already found an RPBM device.
  

•            */
  

•           scan_done = (optee->rpmb_dev ||
  

I suppose we don't need to check for optee->rpmb_dev here since a successful return from optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB) would ensure that the RPMB device has been found.

That makes sense, I'll check the return value instead.

...

•                        !optee->rpmb_dev_request_rescan);
  

•           optee->rpmb_dev_request_rescan = false;
  

•           optee->rpmb_dev_scan_in_progress = !scan_done;
  

•           mutex_unlock(&optee->rpmb_dev_mutex);
  

•   } while (!scan_done);
  

+}

+void optee_rpmb_intf_add_rdev(struct rpmb_interface *intf,

•                         struct rpmb_dev *rdev)
  

+{

•   struct optee *optee = container_of(intf, struct optee, rpmb_intf);
  

•   bool queue_work = true;
  

•   mutex_lock(&optee->rpmb_dev_mutex);
  

•   if (optee->rpmb_dev || optee->rpmb_dev_scan_in_progress) {
  

Can we use work_pending() instead of our custom optee->rpmb_dev_scan_in_progress flag?

That seems racy, or am I missing something?

...

•           queue_work = false;
  

•           if (optee->rpmb_dev_scan_in_progress)
  

•                   optee->rpmb_dev_request_rescan = true;
  

•   }
  

•   if (queue_work)
  

•           optee->rpmb_dev_scan_in_progress = true;
  

•   mutex_unlock(&optee->rpmb_dev_mutex);
  

•   if (queue_work) {
  

•           INIT_WORK(&optee->scan_rpmb_work, optee_rpmb_scan);
  

•           schedule_work(&optee->scan_rpmb_work);
  

Can we reuse optee->scan_bus_work rather than introducing a new one here?

No, both may be active at the same time. We'd have to merge optee_rpmb_scan() and optee_bus_scan(), but I'm not sure it's worth it.

...

•   }
  

+}

static void optee_bus_scan(struct work_struct *work) { WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); @@ -161,6 +213,7 @@ void optee_release_supp(struct tee_context *ctx)

void optee_remove_common(struct optee *optee) {

•   rpmb_interface_unregister(&optee->rpmb_intf);
    /* Unregister OP-TEE specific client devices on TEE bus */
    optee_unregister_devices();
  
  

@@ -177,6 +230,8 @@ void optee_remove_common(struct optee *optee) tee_shm_pool_free(optee->pool); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex);

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
  

}

static int smc_abi_rc; diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index ecb5eb079408..befe19ecc30a 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -7,6 +7,7 @@

#include <linux/arm_ffa.h> #include <linux/errno.h> +#include <linux/rpmb.h> #include <linux/scatterlist.h> #include <linux/sched.h> #include <linux/slab.h> @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee_cq_init(&optee->call_queue, 0); optee_supp_init(&optee->supp); optee_shm_arg_cache_init(optee, arg_cache_flags);

•   mutex_init(&optee->rpmb_dev_mutex);
    ffa_dev_set_drvdata(ffa_dev, optee);
    ctx = teedev_open(optee->teedev);
    if (IS_ERR(ctx)) {
  

@@ -955,6 +957,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) if (rc) goto err_unregister_devices;

•   optee->rpmb_intf.add_rdev = optee_rpmb_intf_add_rdev;
  

•   rpmb_interface_register(&optee->rpmb_intf);
    pr_info("initialized driver\n");
    return 0;
  
  

@@ -968,6 +972,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) teedev_close_context(ctx); err_rhashtable_free: rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
  

•   rpmb_interface_unregister(&optee->rpmb_intf);
    optee_supp_uninit(&optee->supp);
    mutex_destroy(&optee->call_queue.mutex);
    mutex_destroy(&optee->ffa.mutex);
  

diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 7a5243c78b55..1e4c33baef43 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -8,6 +8,7 @@

#include <linux/arm-smccc.h> #include <linux/rhashtable.h> +#include <linux/rpmb.h> #include <linux/semaphore.h> #include <linux/tee_drv.h> #include <linux/types.h> @@ -20,11 +21,13 @@ /* Some Global Platform error codes used in this driver */ #define TEEC_SUCCESS 0x00000000 #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006 +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008 #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A #define TEEC_ERROR_COMMUNICATION 0xFFFF000E #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C #define TEEC_ERROR_BUSY 0xFFFF000D #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010 +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003

#define TEEC_ORIGIN_COMMS 0x00000002

@@ -197,6 +200,8 @@ struct optee_ops {

• @notif: notification synchronization struct
• @supp: supplicant synchronization struct for RPC to supplicant
• @pool: shared memory pool

• • @mutex: mutex protecting @rpmb_dev
• • @rpmb_dev: current RPMB device or NULL
  • @rpc_param_count: If > 0 number of RPC parameters to make room for
  • @scan_bus_done flag if device registation was already done.
  • @scan_bus_work workq to scan optee bus and register optee drivers

@@ -215,9 +220,17 @@ struct optee { struct optee_notif notif; struct optee_supp supp; struct tee_shm_pool *pool;

•   /* Protects rpmb_dev pointer and rpmb_dev_* */
  

•   struct mutex rpmb_dev_mutex;
  

Given my comments above, do we really need this mutex?

I don't see how we can do without the mutex.

...

•   struct rpmb_dev *rpmb_dev;
  

•   bool rpmb_dev_scan_in_progress;
  

•   bool rpmb_dev_request_rescan;
  

•   bool rpmb_dev_scan_done;
  

Left over, should it be dropped?

Thanks, I'll remove it.

...

•   struct rpmb_interface rpmb_intf;
    unsigned int rpc_param_count;
    bool   scan_bus_done;
    struct work_struct scan_bus_work;
  

•   struct work_struct scan_rpmb_work;
  

};

struct optee_session { @@ -280,8 +293,11 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);

#define PTA_CMD_GET_DEVICES 0x0 #define PTA_CMD_GET_DEVICES_SUPP 0x1 +#define PTA_CMD_GET_DEVICES_RPMB 0x2 int optee_enumerate_devices(u32 func); void optee_unregister_devices(void); +void optee_rpmb_intf_add_rdev(struct rpmb_interface *intf,

•                         struct rpmb_dev *rdev);
  
  

int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm, size_t size, size_t align, diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h index f3f06e0994a7..f351a8ac69fc 100644 --- a/drivers/tee/optee/optee_rpc_cmd.h +++ b/drivers/tee/optee/optee_rpc_cmd.h @@ -16,6 +16,14 @@

• and sends responses.

*/

+/*

• • Replay Protected Memory Block access
• • [in] memref[0] Frames to device
• • [out] memref[1] Frames from device
• */

+#define OPTEE_RPC_CMD_RPMB 1

/*

• Get time

@@ -103,4 +111,31 @@ /* I2C master control flags */ #define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)

+/*

• • Reset RPMB probing
• • Releases an eventually already used RPMB devices and starts over searching
• • for RPMB devices. Returns the kind of shared memory to use in subsequent
• • OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
• • [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for

• •                     OPTEE_RPC_CMD_SHM_ALLOC
    

• */

+#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22

+/*

• • Probe next RPMB device
• • [out] value[0].a Type of RPMB device, OPTEE_RPC_RPMB_*
• • [out] value[0].b EXT CSD-slice 168 "RPMB Size"
• • [out] value[0].c EXT CSD-slice 222 "Reliable Write Sector Count"
• • [out] memref[1] Buffer with the raw CID
• */

+#define OPTEE_RPC_CMD_RPMB_PROBE_NEXT 23

+/* Type of RPMB device */ +#define OPTEE_RPC_RPMB_EMMC 0 +#define OPTEE_RPC_RPMB_UFS 1 +#define OPTEE_RPC_RPMB_NVME 2

#endif /*__OPTEE_RPC_CMD_H*/ diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c index e69bc6380683..97f69a108f61 100644 --- a/drivers/tee/optee/rpc.c +++ b/drivers/tee/optee/rpc.c @@ -7,6 +7,7 @@

#include <linux/delay.h> #include <linux/i2c.h> +#include <linux/rpmb.h> #include <linux/slab.h> #include <linux/tee_drv.h> #include "optee_private.h" @@ -255,6 +256,229 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm) optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, &param); }

+static void handle_rpc_func_rpmb_probe_reset(struct tee_context *ctx,

•                                        struct optee *optee,
  

•                                        struct optee_msg_arg *arg)
  

+{

•   struct tee_param params[1];
  

•   if (!IS_ENABLED(CONFIG_RPMB)) {
  

•           handle_rpc_supp_cmd(ctx, optee, arg);
  

•           return;
  

•   }
  

•   if (arg->num_params != ARRAY_SIZE(params) ||
  

•       optee->ops->from_msg_param(optee, params, arg->num_params,
  

•                                  arg->params) ||
  

•       params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT) {
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

•           return;
  

•   }
  

•   params[0].u.value.a = OPTEE_RPC_SHM_TYPE_KERNEL;
  

•   params[0].u.value.b = 0;
  

•   params[0].u.value.c = 0;
  

•   if (optee->ops->to_msg_param(optee, arg->params,
  

•                                arg->num_params, params)) {
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

•           return;
  

•   }
  

•   mutex_lock(&optee->rpmb_dev_mutex);
  

•   rpmb_dev_put(optee->rpmb_dev);
  

•   optee->rpmb_dev = NULL;
  

•   mutex_unlock(&optee->rpmb_dev_mutex);
  

•   arg->ret = TEEC_SUCCESS;
  

+}

+static int rpmb_type_to_rpc_type(enum rpmb_type rtype) +{

•   switch (rtype) {
  

•   case RPMB_TYPE_EMMC:
  

•           return OPTEE_RPC_RPMB_EMMC;
  

•   case RPMB_TYPE_UFS:
  

•           return OPTEE_RPC_RPMB_UFS;
  

•   case RPMB_TYPE_NVME:
  

•           return OPTEE_RPC_RPMB_NVME;
  

•   default:
  

•           return -1;
  

•   }
  

+}

+static int rpc_rpmb_match(struct rpmb_dev *rdev, const void *data) +{

•   return rpmb_type_to_rpc_type(rdev->ops->type) >= 0;
  

+}

+static void handle_rpc_func_rpmb_probe_next(struct tee_context *ctx,

•                                       struct optee *optee,
  

•                                       struct optee_msg_arg *arg)
  

+{

•   struct rpmb_dev *rdev;
  

•   struct tee_param params[2];
  

•   void *buf;
  

•   if (!IS_ENABLED(CONFIG_RPMB)) {
  

What if the RPMB driver is built as a module? IS_REACHABLE() instead?

OK, I'll update.

Thanks, Jens

-Sumit

...

•           handle_rpc_supp_cmd(ctx, optee, arg);
  

•           return;
  

•   }
  

•   if (arg->num_params != ARRAY_SIZE(params) ||
  

•       optee->ops->from_msg_param(optee, params, arg->num_params,
  

•                                  arg->params) ||
  

•       params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT ||
  

•       params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

•           return;
  

•   }
  

•   buf = tee_shm_get_va(params[1].u.memref.shm,
  

•                        params[1].u.memref.shm_offs);
  

•   if (!buf) {
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

•           return;
  

•   }
  

•   mutex_lock(&optee->rpmb_dev_mutex);
  

•   rdev = rpmb_dev_find_device(NULL, optee->rpmb_dev, rpc_rpmb_match);
  

•   rpmb_dev_put(optee->rpmb_dev);
  

•   optee->rpmb_dev = rdev;
  

•   mutex_unlock(&optee->rpmb_dev_mutex);
  

•   if (!rdev) {
  

•           arg->ret = TEEC_ERROR_ITEM_NOT_FOUND;
  

•           return;
  

•   }
  

•   if (params[1].u.memref.size < rdev->dev_id_len) {
  

•           arg->ret = TEEC_ERROR_SHORT_BUFFER;
  

•           return;
  

•   }
  

•   memcpy(buf, rdev->dev_id, rdev->dev_id_len);
  

•   params[1].u.memref.size = rdev->dev_id_len;
  

•   params[0].u.value.a = rpmb_type_to_rpc_type(rdev->ops->type);
  

•   params[0].u.value.b = rdev->capacity;
  

•   params[0].u.value.c = rdev->reliable_wr_count;
  

•   if (optee->ops->to_msg_param(optee, arg->params,
  

•                                arg->num_params, params)) {
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

•           return;
  

•   }
  

•   arg->ret = TEEC_SUCCESS;
  

+}

+/* Request */ +struct rpmb_req {

•   u16 cmd;
  

+#define RPMB_CMD_DATA_REQ 0x00 +#define RPMB_CMD_GET_DEV_INFO 0x01

•   u16 dev_id;
  

•   u16 block_count;
  

•   /* Optional data frames (rpmb_data_frame) follow */
  

+};

+#define RPMB_REQ_DATA(req) ((void *)((struct rpmb_req *)(req) + 1))

+#define RPMB_CID_SZ 16

+/* Response to device info request */ +struct rpmb_dev_info {

•   u8 cid[RPMB_CID_SZ];
  

•   u8 rpmb_size_mult;      /* EXT CSD-slice 168: RPMB Size */
  

•   u8 rel_wr_sec_c;        /* EXT CSD-slice 222: Reliable Write Sector */
  

•                           /*                    Count */
  

•   u8 ret_code;
  

+#define RPMB_CMD_GET_DEV_INFO_RET_OK 0x00 +#define RPMB_CMD_GET_DEV_INFO_RET_ERROR 0x01 +};

+static int get_dev_info(struct rpmb_dev *rdev, void *rsp, size_t rsp_size) +{

•   struct rpmb_dev_info *dev_info;
  

•   if (rsp_size != sizeof(*dev_info))
  

•           return TEEC_ERROR_BAD_PARAMETERS;
  

•   dev_info = rsp;
  

•   memcpy(dev_info->cid, rdev->dev_id, sizeof(dev_info->cid));
  

•   dev_info->rpmb_size_mult = rdev->capacity;
  

•   dev_info->rel_wr_sec_c = rdev->reliable_wr_count;
  

•   dev_info->ret_code = RPMB_CMD_GET_DEV_INFO_RET_OK;
  

•   return TEEC_SUCCESS;
  

+}

+/*

• • req is one struct rpmb_req followed by one or more struct rpmb_data_frame
• • rsp is either one struct rpmb_dev_info or one or more struct rpmb_data_frame
• */

+static u32 rpmb_process_request(struct optee *optee, struct rpmb_dev *rdev,

•                           void *req, size_t req_size,
  

•                           void *rsp, size_t rsp_size)
  

+{

•   struct rpmb_req *sreq = req;
  

•   int rc;
  

•   if (req_size < sizeof(*sreq))
  

•           return TEEC_ERROR_BAD_PARAMETERS;
  

•   switch (sreq->cmd) {
  

•   case RPMB_CMD_DATA_REQ:
  

•           rc = rpmb_route_frames(rdev, RPMB_REQ_DATA(req),
  

•                                  req_size - sizeof(struct rpmb_req),
  

•                                  rsp, rsp_size);
  

•           if (rc)
  

•                   return TEEC_ERROR_BAD_PARAMETERS;
  

•           return TEEC_SUCCESS;
  

•   case RPMB_CMD_GET_DEV_INFO:
  

•           return get_dev_info(rdev, rsp, rsp_size);
  

•   default:
  

•           return TEEC_ERROR_BAD_PARAMETERS;
  

•   }
  

+}

+static void handle_rpc_func_rpmb(struct tee_context *ctx, struct optee *optee,

•                            struct optee_msg_arg *arg)
  

+{

•   struct tee_param params[2];
  

•   struct rpmb_dev *rdev;
  

•   void *p0, *p1;
  

•   mutex_lock(&optee->rpmb_dev_mutex);
  

•   rdev = rpmb_dev_get(optee->rpmb_dev);
  

•   mutex_unlock(&optee->rpmb_dev_mutex);
  

•   if (!rdev) {
  

•           handle_rpc_supp_cmd(ctx, optee, arg);
  

•           return;
  

•   }
  

•   if (arg->num_params != ARRAY_SIZE(params) ||
  

•       optee->ops->from_msg_param(optee, params, arg->num_params,
  

•                                  arg->params) ||
  

•       params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT ||
  

•       params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

•           goto out;
  

•   }
  

•   p0 = tee_shm_get_va(params[0].u.memref.shm,
  

•                       params[0].u.memref.shm_offs);
  

•   p1 = tee_shm_get_va(params[1].u.memref.shm,
  

•                       params[1].u.memref.shm_offs);
  

•   arg->ret = rpmb_process_request(optee, rdev, p0,
  

•                                   params[0].u.memref.size,
  

•                                   p1, params[1].u.memref.size);
  

•   if (arg->ret)
  

•           goto out;
  

•   if (optee->ops->to_msg_param(optee, arg->params,
  

•                                arg->num_params, params))
  

•           arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  

+out:

•   rpmb_dev_put(rdev);
  

+}

void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee, struct optee_msg_arg *arg) { @@ -271,6 +495,15 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee, case OPTEE_RPC_CMD_I2C_TRANSFER: handle_rpc_func_cmd_i2c_transfer(ctx, arg); break;

•   case OPTEE_RPC_CMD_RPMB_PROBE_RESET:
  

•           handle_rpc_func_rpmb_probe_reset(ctx, optee, arg);
  

•           break;
  

•   case OPTEE_RPC_CMD_RPMB_PROBE_NEXT:
  

•           handle_rpc_func_rpmb_probe_next(ctx, optee, arg);
  

•           break;
  

•   case OPTEE_RPC_CMD_RPMB:
  

•           handle_rpc_func_rpmb(ctx, optee, arg);
  

•           break;
    default:
            handle_rpc_supp_cmd(ctx, optee, arg);
    }
  

diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index a37f87087e5c..8da53f41b052 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -20,6 +20,7 @@ #include <linux/of_irq.h> #include <linux/of_platform.h> #include <linux/platform_device.h> +#include <linux/rpmb.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/string.h> @@ -1715,6 +1716,7 @@ static int optee_probe(struct platform_device *pdev) optee->smc.memremaped_shm = memremaped_shm; optee->pool = pool; optee_shm_arg_cache_init(optee, arg_cache_flags);

•   mutex_init(&optee->rpmb_dev_mutex);
  
    platform_set_drvdata(pdev, optee);
    ctx = teedev_open(optee->teedev);
  

@@ -1769,6 +1771,8 @@ static int optee_probe(struct platform_device *pdev) if (rc) goto err_disable_shm_cache;

•   optee->rpmb_intf.add_rdev = optee_rpmb_intf_add_rdev;
  

•   rpmb_interface_register(&optee->rpmb_intf);
    pr_info("initialized driver\n");
    return 0;
  
  

@@ -1782,6 +1786,8 @@ static int optee_probe(struct platform_device *pdev) err_close_ctx: teedev_close_context(ctx); err_supp_uninit:

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
    optee_shm_arg_cache_uninit(optee);
    optee_supp_uninit(&optee->supp);
    mutex_destroy(&optee->call_queue.mutex);
  

-- 2.34.1

On Wed, Apr 3, 2024 at 2:58 PM Sumit Garg sumit.garg@linaro.org wrote:

On Thu, 28 Mar 2024 at 21:39, Jens Wiklander jens.wiklander@linaro.org wrote:

...

On Fri, Mar 1, 2024 at 11:28 AM Sumit Garg sumit.garg@linaro.org wrote:

...

Hi Jens,

On Tue, 27 Feb 2024 at 21:01, Jens Wiklander jens.wiklander@linaro.org wrote:

...

Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and use an RPMB device via the RPBM subsystem instead of passing the RPMB

s/RPBM/RPMB/

Here are other places too in this patch-set.

...

frames via tee-supplicant in user space. A fallback mechanism is kept to route RPMB frames via tee-supplicant if the RPMB subsystem isn't available.

The OP-TEE RPC ABI is extended to support iterating over all RPMB devices until one is found with the expected RPMB key already programmed.

I would appreciate it if you could add a link to OP-TEE OS changes in the cover-letter although I have found them here [1].

[1] https://github.com/jenswi-linaro/optee_os/commits/rpmb_probe/

OK, I'll add a link in the coverletter of the next patch set.

...

...

Signed-off-by: Jens Wiklander jens.wiklander@linaro.org

drivers/tee/optee/core.c | 55 +++++++ drivers/tee/optee/ffa_abi.c | 7 + drivers/tee/optee/optee_private.h | 16 ++ drivers/tee/optee/optee_rpc_cmd.h | 35 +++++ drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++ drivers/tee/optee/smc_abi.c | 6 + 6 files changed, 352 insertions(+)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 3aed554bc8d8..6b32d3e7865b 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -11,6 +11,7 @@ #include <linux/io.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/rpmb.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/tee_drv.h> @@ -80,6 +81,57 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm, shm->pages = NULL; }

+static void optee_rpmb_scan(struct work_struct *work) +{

•   struct optee *optee = container_of(work, struct optee, scan_rpmb_work);
  

•   bool scan_done = false;
  

•   u32 res;
  

•   do {
  

•           mutex_lock(&optee->rpmb_dev_mutex);
  

•           /* No need to rescan if we haven't started scanning yet */
  

•           optee->rpmb_dev_request_rescan = false;
  

•           mutex_unlock(&optee->rpmb_dev_mutex);
  

•           res = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
  

•           if (res && res != TEE_ERROR_STORAGE_NOT_AVAILABLE)
  

I suppose this hasn't been tested for a negative case since optee_enumerate_devices() won't return this error code (see [2]). However, I would prefer to use GP Client error code: TEEC_ERROR_ITEM_NOT_FOUND here instead.

[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/driv...

I prefer TEE_ERROR_STORAGE_NOT_AVAILABLE since that's the code GP says a TA should get when storage is unavailable. TEEC_ERROR_ITEM_NOT_FOUND is less specific. Anyway, I'll need to translate the code in get_devices().

Okay, that's fair.

...

...

...

•                   pr_info("Scanning for RPMB device: res %#x\n", res);
  

•           mutex_lock(&optee->rpmb_dev_mutex);
  

•           /*
  

•            * If another RPMB device came online while scanning, scan one
  

•            * more time, unless we have already found an RPBM device.
  

•            */
  

•           scan_done = (optee->rpmb_dev ||
  

I suppose we don't need to check for optee->rpmb_dev here since a successful return from optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB) would ensure that the RPMB device has been found.

That makes sense, I'll check the return value instead.

...

...

•                        !optee->rpmb_dev_request_rescan);
  

•           optee->rpmb_dev_request_rescan = false;
  

•           optee->rpmb_dev_scan_in_progress = !scan_done;
  

•           mutex_unlock(&optee->rpmb_dev_mutex);
  

•   } while (!scan_done);
  

+}

+void optee_rpmb_intf_add_rdev(struct rpmb_interface *intf,

•                         struct rpmb_dev *rdev)
  

+{

•   struct optee *optee = container_of(intf, struct optee, rpmb_intf);
  

•   bool queue_work = true;
  

•   mutex_lock(&optee->rpmb_dev_mutex);
  

•   if (optee->rpmb_dev || optee->rpmb_dev_scan_in_progress) {
  

Can we use work_pending() instead of our custom optee->rpmb_dev_scan_in_progress flag?

That seems racy, or am I missing something?

You are right and even work_busy() is documented to provide unreliable results. So I am rather thinking about just queuing the work and thereby scanning for devices unconditionally. I suppose the extra logic to check if we don't try to register duplicate devices can go under optee_enumerate_devices().

...

...

...

•           queue_work = false;
  

•           if (optee->rpmb_dev_scan_in_progress)
  

•                   optee->rpmb_dev_request_rescan = true;
  

•   }
  

•   if (queue_work)
  

•           optee->rpmb_dev_scan_in_progress = true;
  

•   mutex_unlock(&optee->rpmb_dev_mutex);
  

•   if (queue_work) {
  

•           INIT_WORK(&optee->scan_rpmb_work, optee_rpmb_scan);
  

•           schedule_work(&optee->scan_rpmb_work);
  

Can we reuse optee->scan_bus_work rather than introducing a new one here?

No, both may be active at the same time.

Actually both of them are using system_wq underneath, so it shouldn't be a problem if both are active at the same time as they can be queued simultaneously, right?

I'm sorry, I don't get it. Are you suggesting to merge optee_rpmb_scan() and optee_bus_scan()? If so, how to tell what to do, that is, if tee-supplicant has become available or of we should scan for RPMB devices? If not, you can only have one callback at a time in a work_struct.

...

We'd have to merge optee_rpmb_scan() and optee_bus_scan(), but I'm not sure it's worth it.

...

...

•   }
  

+}

static void optee_bus_scan(struct work_struct *work) { WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); @@ -161,6 +213,7 @@ void optee_release_supp(struct tee_context *ctx)

void optee_remove_common(struct optee *optee) {

•   rpmb_interface_unregister(&optee->rpmb_intf);
    /* Unregister OP-TEE specific client devices on TEE bus */
    optee_unregister_devices();
  
  

@@ -177,6 +230,8 @@ void optee_remove_common(struct optee *optee) tee_shm_pool_free(optee->pool); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex);

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
  

}

static int smc_abi_rc; diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index ecb5eb079408..befe19ecc30a 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -7,6 +7,7 @@

#include <linux/arm_ffa.h> #include <linux/errno.h> +#include <linux/rpmb.h> #include <linux/scatterlist.h> #include <linux/sched.h> #include <linux/slab.h> @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee_cq_init(&optee->call_queue, 0); optee_supp_init(&optee->supp); optee_shm_arg_cache_init(optee, arg_cache_flags);

•   mutex_init(&optee->rpmb_dev_mutex);
    ffa_dev_set_drvdata(ffa_dev, optee);
    ctx = teedev_open(optee->teedev);
    if (IS_ERR(ctx)) {
  

@@ -955,6 +957,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) if (rc) goto err_unregister_devices;

•   optee->rpmb_intf.add_rdev = optee_rpmb_intf_add_rdev;
  

•   rpmb_interface_register(&optee->rpmb_intf);
    pr_info("initialized driver\n");
    return 0;
  
  

@@ -968,6 +972,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) teedev_close_context(ctx); err_rhashtable_free: rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
  

•   rpmb_interface_unregister(&optee->rpmb_intf);
    optee_supp_uninit(&optee->supp);
    mutex_destroy(&optee->call_queue.mutex);
    mutex_destroy(&optee->ffa.mutex);
  

diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 7a5243c78b55..1e4c33baef43 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -8,6 +8,7 @@

#include <linux/arm-smccc.h> #include <linux/rhashtable.h> +#include <linux/rpmb.h> #include <linux/semaphore.h> #include <linux/tee_drv.h> #include <linux/types.h> @@ -20,11 +21,13 @@ /* Some Global Platform error codes used in this driver */ #define TEEC_SUCCESS 0x00000000 #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006 +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008 #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A #define TEEC_ERROR_COMMUNICATION 0xFFFF000E #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C #define TEEC_ERROR_BUSY 0xFFFF000D #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010 +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003

#define TEEC_ORIGIN_COMMS 0x00000002

@@ -197,6 +200,8 @@ struct optee_ops {

• @notif: notification synchronization struct
• @supp: supplicant synchronization struct for RPC to supplicant
• @pool: shared memory pool

• • @mutex: mutex protecting @rpmb_dev
• • @rpmb_dev: current RPMB device or NULL
  • @rpc_param_count: If > 0 number of RPC parameters to make room for
  • @scan_bus_done flag if device registation was already done.
  • @scan_bus_work workq to scan optee bus and register optee drivers

@@ -215,9 +220,17 @@ struct optee { struct optee_notif notif; struct optee_supp supp; struct tee_shm_pool *pool;

•   /* Protects rpmb_dev pointer and rpmb_dev_* */
  

•   struct mutex rpmb_dev_mutex;
  

Given my comments above, do we really need this mutex?

I don't see how we can do without the mutex.

See if it is possible with the above mentioned approach.

I don't follow.

Thanks, Jens

-Sumit

On Fri, Apr 5, 2024 at 9:15 AM Sumit Garg sumit.garg@linaro.org wrote:

On Wed, 3 Apr 2024 at 20:11, Jens Wiklander jens.wiklander@linaro.org wrote:

...

On Wed, Apr 3, 2024 at 2:58 PM Sumit Garg sumit.garg@linaro.org wrote:

...

On Thu, 28 Mar 2024 at 21:39, Jens Wiklander jens.wiklander@linaro.org wrote:

...

On Fri, Mar 1, 2024 at 11:28 AM Sumit Garg sumit.garg@linaro.org wrote:

...

Hi Jens,

On Tue, 27 Feb 2024 at 21:01, Jens Wiklander jens.wiklander@linaro.org wrote:

...

Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and use an RPMB device via the RPBM subsystem instead of passing the RPMB

s/RPBM/RPMB/

Here are other places too in this patch-set.

...

frames via tee-supplicant in user space. A fallback mechanism is kept to route RPMB frames via tee-supplicant if the RPMB subsystem isn't available.

The OP-TEE RPC ABI is extended to support iterating over all RPMB devices until one is found with the expected RPMB key already programmed.

I would appreciate it if you could add a link to OP-TEE OS changes in the cover-letter although I have found them here [1].

[1] https://github.com/jenswi-linaro/optee_os/commits/rpmb_probe/

OK, I'll add a link in the coverletter of the next patch set.

...

...

Signed-off-by: Jens Wiklander jens.wiklander@linaro.org

drivers/tee/optee/core.c | 55 +++++++ drivers/tee/optee/ffa_abi.c | 7 + drivers/tee/optee/optee_private.h | 16 ++ drivers/tee/optee/optee_rpc_cmd.h | 35 +++++ drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++ drivers/tee/optee/smc_abi.c | 6 + 6 files changed, 352 insertions(+)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 3aed554bc8d8..6b32d3e7865b 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -11,6 +11,7 @@ #include <linux/io.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/rpmb.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/tee_drv.h> @@ -80,6 +81,57 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm, shm->pages = NULL; }

+static void optee_rpmb_scan(struct work_struct *work) +{

•   struct optee *optee = container_of(work, struct optee, scan_rpmb_work);
  

•   bool scan_done = false;
  

•   u32 res;
  

•   do {
  

•           mutex_lock(&optee->rpmb_dev_mutex);
  

•           /* No need to rescan if we haven't started scanning yet */
  

•           optee->rpmb_dev_request_rescan = false;
  

•           mutex_unlock(&optee->rpmb_dev_mutex);
  

•           res = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
  

•           if (res && res != TEE_ERROR_STORAGE_NOT_AVAILABLE)
  

I suppose this hasn't been tested for a negative case since optee_enumerate_devices() won't return this error code (see [2]). However, I would prefer to use GP Client error code: TEEC_ERROR_ITEM_NOT_FOUND here instead.

[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/driv...

I prefer TEE_ERROR_STORAGE_NOT_AVAILABLE since that's the code GP says a TA should get when storage is unavailable. TEEC_ERROR_ITEM_NOT_FOUND is less specific. Anyway, I'll need to translate the code in get_devices().

Okay, that's fair.

...

...

...

•                   pr_info("Scanning for RPMB device: res %#x\n", res);
  

•           mutex_lock(&optee->rpmb_dev_mutex);
  

•           /*
  

•            * If another RPMB device came online while scanning, scan one
  

•            * more time, unless we have already found an RPBM device.
  

•            */
  

•           scan_done = (optee->rpmb_dev ||
  

I suppose we don't need to check for optee->rpmb_dev here since a successful return from optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB) would ensure that the RPMB device has been found.

That makes sense, I'll check the return value instead.

...

...

•                        !optee->rpmb_dev_request_rescan);
  

•           optee->rpmb_dev_request_rescan = false;
  

•           optee->rpmb_dev_scan_in_progress = !scan_done;
  

•           mutex_unlock(&optee->rpmb_dev_mutex);
  

•   } while (!scan_done);
  

+}

+void optee_rpmb_intf_add_rdev(struct rpmb_interface *intf,

•                         struct rpmb_dev *rdev)
  

+{

•   struct optee *optee = container_of(intf, struct optee, rpmb_intf);
  

•   bool queue_work = true;
  

•   mutex_lock(&optee->rpmb_dev_mutex);
  

•   if (optee->rpmb_dev || optee->rpmb_dev_scan_in_progress) {
  

Can we use work_pending() instead of our custom optee->rpmb_dev_scan_in_progress flag?

That seems racy, or am I missing something?

You are right and even work_busy() is documented to provide unreliable results. So I am rather thinking about just queuing the work and thereby scanning for devices unconditionally. I suppose the extra logic to check if we don't try to register duplicate devices can go under optee_enumerate_devices().

...

...

...

•           queue_work = false;
  

•           if (optee->rpmb_dev_scan_in_progress)
  

•                   optee->rpmb_dev_request_rescan = true;
  

•   }
  

•   if (queue_work)
  

•           optee->rpmb_dev_scan_in_progress = true;
  

•   mutex_unlock(&optee->rpmb_dev_mutex);
  

•   if (queue_work) {
  

•           INIT_WORK(&optee->scan_rpmb_work, optee_rpmb_scan);
  

•           schedule_work(&optee->scan_rpmb_work);
  

Can we reuse optee->scan_bus_work rather than introducing a new one here?

No, both may be active at the same time.

Actually both of them are using system_wq underneath, so it shouldn't be a problem if both are active at the same time as they can be queued simultaneously, right?

I'm sorry, I don't get it. Are you suggesting to merge optee_rpmb_scan() and optee_bus_scan()? If so, how to tell what to do, that is, if tee-supplicant has become available or of we should scan for RPMB devices? If not, you can only have one callback at a time in a work_struct.

You are right, keep it as it is.

...

...

...

We'd have to merge optee_rpmb_scan() and optee_bus_scan(), but I'm not sure it's worth it.

...

...

•   }
  

+}

static void optee_bus_scan(struct work_struct *work) { WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); @@ -161,6 +213,7 @@ void optee_release_supp(struct tee_context *ctx)

void optee_remove_common(struct optee *optee) {

•   rpmb_interface_unregister(&optee->rpmb_intf);
    /* Unregister OP-TEE specific client devices on TEE bus */
    optee_unregister_devices();
  
  

@@ -177,6 +230,8 @@ void optee_remove_common(struct optee *optee) tee_shm_pool_free(optee->pool); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex);

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
  

}

static int smc_abi_rc; diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index ecb5eb079408..befe19ecc30a 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -7,6 +7,7 @@

#include <linux/arm_ffa.h> #include <linux/errno.h> +#include <linux/rpmb.h> #include <linux/scatterlist.h> #include <linux/sched.h> #include <linux/slab.h> @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee_cq_init(&optee->call_queue, 0); optee_supp_init(&optee->supp); optee_shm_arg_cache_init(optee, arg_cache_flags);

•   mutex_init(&optee->rpmb_dev_mutex);
    ffa_dev_set_drvdata(ffa_dev, optee);
    ctx = teedev_open(optee->teedev);
    if (IS_ERR(ctx)) {
  

@@ -955,6 +957,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) if (rc) goto err_unregister_devices;

•   optee->rpmb_intf.add_rdev = optee_rpmb_intf_add_rdev;
  

•   rpmb_interface_register(&optee->rpmb_intf);
    pr_info("initialized driver\n");
    return 0;
  
  

@@ -968,6 +972,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) teedev_close_context(ctx); err_rhashtable_free: rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);

•   rpmb_dev_put(optee->rpmb_dev);
  

•   mutex_destroy(&optee->rpmb_dev_mutex);
  

•   rpmb_interface_unregister(&optee->rpmb_intf);
    optee_supp_uninit(&optee->supp);
    mutex_destroy(&optee->call_queue.mutex);
    mutex_destroy(&optee->ffa.mutex);
  

diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 7a5243c78b55..1e4c33baef43 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -8,6 +8,7 @@

#include <linux/arm-smccc.h> #include <linux/rhashtable.h> +#include <linux/rpmb.h> #include <linux/semaphore.h> #include <linux/tee_drv.h> #include <linux/types.h> @@ -20,11 +21,13 @@ /* Some Global Platform error codes used in this driver */ #define TEEC_SUCCESS 0x00000000 #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006 +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008 #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A #define TEEC_ERROR_COMMUNICATION 0xFFFF000E #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C #define TEEC_ERROR_BUSY 0xFFFF000D #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010 +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003

#define TEEC_ORIGIN_COMMS 0x00000002

@@ -197,6 +200,8 @@ struct optee_ops {

• @notif: notification synchronization struct
• @supp: supplicant synchronization struct for RPC to supplicant
• @pool: shared memory pool

• • @mutex: mutex protecting @rpmb_dev
• • @rpmb_dev: current RPMB device or NULL
  • @rpc_param_count: If > 0 number of RPC parameters to make room for
  • @scan_bus_done flag if device registation was already done.
  • @scan_bus_work workq to scan optee bus and register optee drivers

@@ -215,9 +220,17 @@ struct optee { struct optee_notif notif; struct optee_supp supp; struct tee_shm_pool *pool;

•   /* Protects rpmb_dev pointer and rpmb_dev_* */
  

•   struct mutex rpmb_dev_mutex;
  

Given my comments above, do we really need this mutex?

I don't see how we can do without the mutex.

See if it is possible with the above mentioned approach.

I don't follow.

Probably my explanation above to handle complexity within optee_enumerate_devices() wasn't clear. Let me try again:

• Schedule optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB)

unconditionally whenever a new RPMB device is registered.

• While registering OP-TEE devices (TA UUIDs), don't register

duplicate devices or better make the device pseudo TA to return the UUID list only once when RPMB has been discovered successfully.

This would allow us to drop the fragile handling via rpmb_dev_scan_in_progress under mutex, right?

I got it now. I'll do that in the v4. Thanks for your patience. :-)

Cheers, Jens