Hi Jens,

Thanks for the feedback. I noticed that IDR is deprecated now so for the next version I replaced it with XArray, which also addresses some of the issues you found.

On 15 Feb 2024, at 11:00, Jens Wiklander wrote:

Hi Balint,

On Tue, Feb 13, 2024 at 3:54 PM Balint Dobszay balint.dobszay@arm.com wrote:

...

The Trusted Services project provides a framework for developing and deploying device Root of Trust services in FF-A Secure Partitions. The FF-A SPs are accessible through the FF-A driver, but this doesn't provide a user space interface. The goal of this TEE driver is to make Trusted Services SPs accessible for user space clients.

All TS SPs have the same FF-A UUID, it identifies the RPC protocol used by TS. A TS SP can host one or more services, a service is identified by its service UUID. The same type of service cannot be present twice in the same SP. During SP boot each service in an SP is assigned an interface ID, this is just a short ID to simplify message addressing. There is 1:1 mapping between TS SPs and TEE devices, i.e. a separate TEE device is registered for each TS SP. This is required since contrary to the generic TEE design where memory is shared with the whole TEE implementation, in case of FF-A, memory is shared with a specific SP. A user space client has to be able to separately share memory with each SP based on its endpoint ID.

Signed-off-by: Balint Dobszay balint.dobszay@arm.com

drivers/tee/Kconfig | 1 + drivers/tee/Makefile | 1 + drivers/tee/tstee/Kconfig | 11 + drivers/tee/tstee/Makefile | 3 + drivers/tee/tstee/core.c | 501 ++++++++++++++++++++++++++++++ drivers/tee/tstee/tstee_private.h | 92 ++++++ include/uapi/linux/tee.h | 1 + 7 files changed, 610 insertions(+) create mode 100644 drivers/tee/tstee/Kconfig create mode 100644 drivers/tee/tstee/Makefile create mode 100644 drivers/tee/tstee/core.c create mode 100644 drivers/tee/tstee/tstee_private.h

diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig index 73a147202e88..61b507c18780 100644 --- a/drivers/tee/Kconfig +++ b/drivers/tee/Kconfig @@ -15,5 +15,6 @@ if TEE

source "drivers/tee/optee/Kconfig" source "drivers/tee/amdtee/Kconfig" +source "drivers/tee/tstee/Kconfig"

endif diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile index 68da044afbfa..5488cba30bd2 100644 --- a/drivers/tee/Makefile +++ b/drivers/tee/Makefile @@ -5,3 +5,4 @@ tee-objs += tee_shm.o tee-objs += tee_shm_pool.o obj-$(CONFIG_OPTEE) += optee/ obj-$(CONFIG_AMDTEE) += amdtee/ +obj-$(CONFIG_ARM_TSTEE) += tstee/ diff --git a/drivers/tee/tstee/Kconfig b/drivers/tee/tstee/Kconfig new file mode 100644 index 000000000000..d32f91d47398 --- /dev/null +++ b/drivers/tee/tstee/Kconfig @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0-only +config ARM_TSTEE

•   tristate "Arm Trusted Services TEE driver"
  

•   depends on ARM_FFA_TRANSPORT
  

•   default n
  

•   help
  

•     The Trusted Services project provides a framework for developing and
  

•     deploying device Root of Trust services in FF-A Secure Partitions.
  

•     This driver provides an interface to make Trusted Services Secure
  

•     Partitions accessible for user space clients, since the FF-A driver
  

•     doesn't implement a user space interface directly.
  

diff --git a/drivers/tee/tstee/Makefile b/drivers/tee/tstee/Makefile new file mode 100644 index 000000000000..5227020ebd30 --- /dev/null +++ b/drivers/tee/tstee/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +arm-tstee-objs := core.o +obj-$(CONFIG_ARM_TSTEE) = arm-tstee.o diff --git a/drivers/tee/tstee/core.c b/drivers/tee/tstee/core.c new file mode 100644 index 000000000000..8d6bbe4d03ed --- /dev/null +++ b/drivers/tee/tstee/core.c @@ -0,0 +1,501 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*

• • Copyright (c) 2023, Arm Limited
• */

+#define DRIVER_NAME "Arm TSTEE" +#define pr_fmt(fmt) DRIVER_NAME ": " fmt

+#include <linux/arm_ffa.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> +#include <linux/stat.h> +#include <linux/tee_drv.h> +#include <linux/types.h> +#include <linux/uaccess.h>

+#include "tstee_private.h"

+#define FFA_DIRECT_REQ_ARG_NUM 5 +#define FFA_INVALID_MEM_HANDLE U64_MAX

+static void arg_list_to_ffa_data(const u32 *args, struct ffa_send_direct_data *data)

The preferred limit on the length of a single line is 80 columns https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-lo...

Sure, I'll reformat.

...

+{

•   data->data0 = args[0];
  

•   data->data1 = args[1];
  

•   data->data2 = args[2];
  

•   data->data3 = args[3];
  

•   data->data4 = args[4];
  

+}

+static void arg_list_from_ffa_data(const struct ffa_send_direct_data *data, u32 *args) +{

•   args[0] = lower_32_bits(data->data0);
  

•   args[1] = lower_32_bits(data->data1);
  

•   args[2] = lower_32_bits(data->data2);
  

•   args[3] = lower_32_bits(data->data3);
  

•   args[4] = lower_32_bits(data->data4);
  

+}

+static void tstee_get_version(struct tee_device *teedev, struct tee_ioctl_version_data *vers) +{

•   struct tstee *tstee = tee_get_drvdata(teedev);
  

•   struct tee_ioctl_version_data v = {
  

•           .impl_id = TEE_IMPL_ID_TSTEE,
  

•           /* FF-A endpoint ID only uses the lower 16 bits */
  

•           .impl_caps = lower_16_bits(tstee->ffa_dev->vm_id),
  

•           .gen_caps = 0,
  

•   };
  

•   *vers = v;
  

+}

+static int tstee_open(struct tee_context *ctx) +{

•   struct ts_context_data *ctxdata;
  

•   ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
  

•   if (!ctxdata)
  

•           return -ENOMEM;
  

•   mutex_init(&ctxdata->mutex);
  

•   idr_init(&ctxdata->sess_ids);
  

•   INIT_LIST_HEAD(&ctxdata->sess_list);
  

•   ctx->data = ctxdata;
  

•   return 0;
  

+}

+static void tstee_release(struct tee_context *ctx) +{

•   struct ts_context_data *ctxdata = ctx->data;
  

•   struct ts_session *sess, *sess_tmp;
  

•   if (!ctxdata)
  

•           return;
  

•   list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list, list_node) {
  

•           list_del(&sess->list_node);
  

•           idr_remove(&ctxdata->sess_ids, sess->session_id);
  

•           kfree(sess);
  

•   }
  

•   idr_destroy(&ctxdata->sess_ids);
  

•   mutex_destroy(&ctxdata->mutex);
  

•   kfree(ctxdata);
  

•   ctx->data = NULL;
  

+}

+static struct ts_session *find_session(struct ts_context_data *ctxdata, u32 session_id) +{

•   struct ts_session *sess;
  

•   list_for_each_entry(sess, &ctxdata->sess_list, list_node)
  

•           if (sess->session_id == session_id)
  

•                   return sess;
  

Since you have an idr, why not use idr_find() instead?

Good point, anyway this got removed due to using XArray.

...

•   return NULL;
  

+}

+static int tstee_open_session(struct tee_context *ctx, struct tee_ioctl_open_session_arg *arg,

•                         struct tee_param *param __always_unused)
  

+{

•   struct tstee *tstee = tee_get_drvdata(ctx->teedev);
  

•   struct ffa_device *ffa_dev = tstee->ffa_dev;
  

•   struct ts_context_data *ctxdata = ctx->data;
  

•   struct ffa_send_direct_data ffa_data;
  

•   struct ts_session *sess = NULL;
  

•   u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
  

•   int sess_id;
  

•   int rc;
  

•   ffa_args[TS_RPC_CTRL_REG] = TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
  

•                                                             TS_RPC_OP_SERVICE_INFO);
  

•   memcpy((u8 *)(ffa_args + TS_RPC_SERVICE_INFO_UUID0), arg->uuid, UUID_SIZE);
  

Is the cast needed?

It's not needed, removed.

...

•   arg_list_to_ffa_data(ffa_args, &ffa_data);
  

•   rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
  

•   if (rc)
  

•           return rc;
  

•   arg_list_from_ffa_data(&ffa_data, ffa_args);
  

•   if (ffa_args[TS_RPC_SERVICE_INFO_RPC_STATUS] != TS_RPC_OK)
  

•           return -ENODEV;
  

•   if (ffa_args[TS_RPC_SERVICE_INFO_IFACE] > U8_MAX)
  

•           return -EINVAL;
  

•   sess = kzalloc(sizeof(*sess), GFP_KERNEL);
  

•   if (!sess)
  

•           return -ENOMEM;
  

•   sess_id = idr_alloc(&ctxdata->sess_ids, sess, 1, 0, GFP_KERNEL);
  

This needs to be protected by the mutex.

After replacing this with xa_alloc() my understanding is that the mutex will not be needed here.

...

•   if (sess_id < 0) {
  

•           kfree(sess);
  

•           return sess_id;
  

•   }
  

•   sess->session_id = sess_id;
  

•   sess->iface_id = ffa_args[TS_RPC_SERVICE_INFO_IFACE];
  

•   mutex_lock(&ctxdata->mutex);
  

•   list_add(&sess->list_node, &ctxdata->sess_list);
  

•   mutex_unlock(&ctxdata->mutex);
  

•   arg->session = sess_id;
  

•   arg->ret = 0;
  

•   return 0;
  

+}

+static int tstee_close_session(struct tee_context *ctx, u32 session) +{

•   struct ts_context_data *ctxdata = ctx->data;
  

•   struct ts_session *sess;
  

•   mutex_lock(&ctxdata->mutex);
  

•   sess = find_session(ctxdata, session);
  

•   if (sess)
  

•           list_del(&sess->list_node);
  

•   mutex_unlock(&ctxdata->mutex);
  

•   if (!sess)
  

•           return -EINVAL;
  

•   idr_remove(&ctxdata->sess_ids, sess->session_id);
  

•   kfree(sess);
  

•   return 0;
  

+}

+static int tstee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,

•                        struct tee_param *param)
  

+{

•   struct tstee *tstee = tee_get_drvdata(ctx->teedev);
  

•   struct ffa_device *ffa_dev = tstee->ffa_dev;
  

•   struct ts_context_data *ctxdata = ctx->data;
  

•   struct ffa_send_direct_data ffa_data;
  

•   struct tee_shm *shm = NULL;
  

•   struct ts_session *sess;
  

•   u32 req_len, ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
  

•   int shm_id, rc;
  

•   u8 iface_id;
  

•   u64 handle;
  

•   u16 opcode;
  

•   mutex_lock(&ctxdata->mutex);
  

•   sess = find_session(ctxdata, arg->session);
  

•   /* Do this while holding the mutex to make sure that the session wasn't closed meanwhile */
  

•   if (sess)
  

•           iface_id = sess->iface_id;
  

•   mutex_unlock(&ctxdata->mutex);
  

•   if (!sess)
  

•           return -EINVAL;
  

•   opcode = lower_16_bits(arg->func);
  

•   shm_id = lower_32_bits(param[0].u.value.a);
  

•   req_len = lower_32_bits(param[0].u.value.b);
  

•   if (shm_id != 0) {
  

•           shm = tee_shm_get_from_id(ctx, shm_id);
  

•           if (IS_ERR(shm))
  

•                   return PTR_ERR(shm);
  

•           if (shm->size < req_len) {
  

•                   pr_err("request doesn't fit into shared memory buffer\n");
  

•                   rc = -EINVAL;
  

•                   goto out;
  

•           }
  

•           handle = shm->sec_world_id;
  

•   } else {
  

•           handle = FFA_INVALID_MEM_HANDLE;
  

•   }
  

•   ffa_args[TS_RPC_CTRL_REG] = TS_RPC_CTRL_PACK_IFACE_OPCODE(iface_id, opcode);
  

•   ffa_args[TS_RPC_SERVICE_MEM_HANDLE_LSW] = lower_32_bits(handle);
  

•   ffa_args[TS_RPC_SERVICE_MEM_HANDLE_MSW] = upper_32_bits(handle);
  

•   ffa_args[TS_RPC_SERVICE_REQ_LEN] = req_len;
  

•   ffa_args[TS_RPC_SERVICE_CLIENT_ID] = 0;
  

•   arg_list_to_ffa_data(ffa_args, &ffa_data);
  

•   rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
  

•   if (rc)
  

•           goto out;
  

•   arg_list_from_ffa_data(&ffa_data, ffa_args);
  

•   if (ffa_args[TS_RPC_SERVICE_RPC_STATUS] != TS_RPC_OK) {
  

•           pr_err("invoke_func rpc status: %d\n", ffa_args[TS_RPC_SERVICE_RPC_STATUS]);
  

•           rc = -EINVAL;
  

•           goto out;
  

•   }
  

•   arg->ret = ffa_args[TS_RPC_SERVICE_STATUS];
  

•   if (shm && shm->size >= ffa_args[TS_RPC_SERVICE_RESP_LEN])
  

•           param[0].u.value.a = ffa_args[TS_RPC_SERVICE_RESP_LEN];
  

+out:

•   if (shm)
  

•           tee_shm_put(shm);
  

•   return rc;
  

+}

+static int tstee_shm_register(struct tee_context *ctx, struct tee_shm *shm, struct page **pages,

•                         size_t num_pages, unsigned long start __always_unused)
  

+{

•   struct tstee *tstee = tee_get_drvdata(ctx->teedev);
  

•   struct ffa_device *ffa_dev = tstee->ffa_dev;
  

•   struct ffa_mem_region_attributes mem_attr = {
  

•           .receiver = tstee->ffa_dev->vm_id,
  

•           .attrs = FFA_MEM_RW,
  

•           .flag = 0,
  

•   };
  

•   struct ffa_mem_ops_args mem_args = {
  

•           .attrs = &mem_attr,
  

•           .use_txbuf = true,
  

•           .nattrs = 1,
  

•           .flags = 0,
  

•   };
  

•   struct ffa_send_direct_data ffa_data;
  

•   struct sg_table sgt;
  

•   u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
  

•   int rc;
  

•   rc = sg_alloc_table_from_pages(&sgt, pages, num_pages, 0, num_pages * PAGE_SIZE,
  

•                                  GFP_KERNEL);
  

•   if (rc)
  

•           return rc;
  

•   mem_args.sg = sgt.sgl;
  

•   rc = ffa_dev->ops->mem_ops->memory_share(&mem_args);
  

•   sg_free_table(&sgt);
  

•   if (rc)
  

•           return rc;
  

•   shm->sec_world_id = mem_args.g_handle;
  

•   ffa_args[TS_RPC_CTRL_REG] = TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
  

•                                                             TS_RPC_OP_RETRIEVE_MEM);
  

•   ffa_args[TS_RPC_RETRIEVE_MEM_HANDLE_LSW] = lower_32_bits(shm->sec_world_id);
  

•   ffa_args[TS_RPC_RETRIEVE_MEM_HANDLE_MSW] = upper_32_bits(shm->sec_world_id);
  

•   ffa_args[TS_RPC_RETRIEVE_MEM_TAG_LSW] = 0;
  

•   ffa_args[TS_RPC_RETRIEVE_MEM_TAG_MSW] = 0;
  

•   arg_list_to_ffa_data(ffa_args, &ffa_data);
  

•   rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
  

•   if (rc) {
  

•           (void)ffa_dev->ops->mem_ops->memory_reclaim(shm->sec_world_id, 0);
  

•           return rc;
  

•   }
  

•   arg_list_from_ffa_data(&ffa_data, ffa_args);
  

•   if (ffa_args[TS_RPC_RETRIEVE_MEM_RPC_STATUS] != TS_RPC_OK) {
  

•           pr_err("shm_register rpc status: %d\n", ffa_args[TS_RPC_RETRIEVE_MEM_RPC_STATUS]);
  

•           ffa_dev->ops->mem_ops->memory_reclaim(shm->sec_world_id, 0);
  

•           return -EINVAL;
  

•   }
  

•   return 0;
  

+}

+static int tstee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm) +{

•   struct tstee *tstee = tee_get_drvdata(ctx->teedev);
  

•   struct ffa_device *ffa_dev = tstee->ffa_dev;
  

•   struct ffa_send_direct_data ffa_data;
  

•   u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
  

•   int rc;
  

•   ffa_args[TS_RPC_CTRL_REG] = TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
  

•                                                             TS_RPC_OP_RELINQ_MEM);
  

•   ffa_args[TS_RPC_RELINQ_MEM_HANDLE_LSW] = lower_32_bits(shm->sec_world_id);
  

•   ffa_args[TS_RPC_RELINQ_MEM_HANDLE_MSW] = upper_32_bits(shm->sec_world_id);
  

•   arg_list_to_ffa_data(ffa_args, &ffa_data);
  

•   rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
  

•   if (rc)
  

•           return rc;
  

•   arg_list_from_ffa_data(&ffa_data, ffa_args);
  

•   if (ffa_args[TS_RPC_RELINQ_MEM_RPC_STATUS] != TS_RPC_OK) {
  

•           pr_err("shm_unregister rpc status: %d\n", ffa_args[TS_RPC_RELINQ_MEM_RPC_STATUS]);
  

•           return -EINVAL;
  

•   }
  

•   rc = ffa_dev->ops->mem_ops->memory_reclaim(shm->sec_world_id, 0);
  

•   return rc;
  

+}

+static const struct tee_driver_ops tstee_ops = {

•   .get_version = tstee_get_version,
  

•   .open = tstee_open,
  

•   .release = tstee_release,
  

•   .open_session = tstee_open_session,
  

•   .close_session = tstee_close_session,
  

•   .invoke_func = tstee_invoke_func,
  

•   .shm_register = tstee_shm_register,
  

•   .shm_unregister = tstee_shm_unregister,
  

+};

+static const struct tee_desc tstee_desc = {

•   .name = "tstee-clnt",
  

•   .ops = &tstee_ops,
  

•   .owner = THIS_MODULE,
  

+};

+static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm, size_t size, size_t align) +{

•   return tee_shm_pool_op_alloc_helper(pool, shm, size, align, tstee_shm_register);
  

+}

+static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm) +{

•   tee_shm_pool_op_free_helper(pool, shm, tstee_shm_unregister);
  

+}

+static void pool_op_destroy_pool(struct tee_shm_pool *pool) +{

•   kfree(pool);
  

+}

+static const struct tee_shm_pool_ops pool_ops = {

•   .alloc = pool_op_alloc,
  

•   .free = pool_op_free,
  

•   .destroy_pool = pool_op_destroy_pool,
  

+};

+static struct tee_shm_pool *tstee_create_shm_pool(void) +{

•   struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
  

•   if (!pool)
  

•           return ERR_PTR(-ENOMEM);
  

•   pool->ops = &pool_ops;
  

•   return pool;
  

+}

+static bool tstee_check_rpc_compatible(struct ffa_device *ffa_dev) +{

•   struct ffa_send_direct_data ffa_data;
  

•   u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
  

•   ffa_args[TS_RPC_CTRL_REG] = TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
  

•                                                             TS_RPC_OP_GET_VERSION);
  

•   arg_list_to_ffa_data(ffa_args, &ffa_data);
  

•   if (ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data))
  

•           return false;
  

•   arg_list_from_ffa_data(&ffa_data, ffa_args);
  

•   return ffa_args[TS_RPC_GET_VERSION_RESP] == TS_RPC_PROTOCOL_VERSION;
  

+}

+static void tstee_deinit_common(struct tstee *tstee) +{

•   tee_device_unregister(tstee->teedev);
  

•   if (tstee->pool)
  

•           tee_shm_pool_free(tstee->pool);
  

•   kfree(tstee);
  

+}

+static int tstee_probe(struct ffa_device *ffa_dev) +{

•   struct tstee *tstee;
  

•   int rc;
  

•   ffa_dev->ops->msg_ops->mode_32bit_set(ffa_dev);
  

•   if (!tstee_check_rpc_compatible(ffa_dev))
  

•           return -EINVAL;
  

•   tstee = kzalloc(sizeof(*tstee), GFP_KERNEL);
  

•   if (!tstee)
  

•           return -ENOMEM;
  

•   tstee->ffa_dev = ffa_dev;
  

•   tstee->pool = tstee_create_shm_pool();
  

•   if (IS_ERR(tstee->pool)) {
  

•           rc = PTR_ERR(tstee->pool);
  

•           tstee->pool = NULL;
  

•           goto err;
  

•   }
  

•   tstee->teedev = tee_device_alloc(&tstee_desc, NULL, tstee->pool, tstee);
  

•   if (IS_ERR(tstee->teedev)) {
  

•           rc = PTR_ERR(tstee->teedev);
  

•           tstee->teedev = NULL;
  

•           goto err;
  

•   }
  

•   rc = tee_device_register(tstee->teedev);
  

•   if (rc)
  

•           goto err;
  

•   ffa_dev_set_drvdata(ffa_dev, tstee);
  

•   pr_info("driver initialized for endpoint 0x%x\n", ffa_dev->vm_id);
  

•   return 0;
  

+err:

•   tstee_deinit_common(tstee);
  

•   return rc;
  

+}

+static void tstee_remove(struct ffa_device *ffa_dev) +{

•   tstee_deinit_common(ffa_dev->dev.driver_data);
  

+}

+static const struct ffa_device_id tstee_device_ids[] = {

•   /* TS RPC protocol UUID: bdcd76d7-825e-4751-963b-86d4f84943ac */
  

•   { TS_RPC_UUID },
  

•   {}
  

+};

+static struct ffa_driver tstee_driver = {

•   .name = "arm_tstee",
  

•   .probe = tstee_probe,
  

•   .remove = tstee_remove,
  

•   .id_table = tstee_device_ids,
  

+};

+static int __init mod_init(void) +{

•   return ffa_register(&tstee_driver);
  

+} +module_init(mod_init)

+static void __exit mod_exit(void) +{

•   ffa_unregister(&tstee_driver);
  

+} +module_exit(mod_exit)

+MODULE_ALIAS("arm-tstee"); +MODULE_AUTHOR("Balint Dobszay balint.dobszay@arm.com"); +MODULE_DESCRIPTION("Arm Trusted Services TEE driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/tee/tstee/tstee_private.h b/drivers/tee/tstee/tstee_private.h new file mode 100644 index 000000000000..81eeda220a5c --- /dev/null +++ b/drivers/tee/tstee/tstee_private.h @@ -0,0 +1,92 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/*

• • Copyright (c) 2023, Arm Limited
• */

+#ifndef TSTEE_PRIVATE_H +#define TSTEE_PRIVATE_H

+#include <linux/arm_ffa.h> +#include <linux/bitops.h> +#include <linux/idr.h> +#include <linux/tee_drv.h> +#include <linux/types.h> +#include <linux/uuid.h>

+/* UUID of this protocol */

It would be nice to have a link or reference to the description of the ABI.

The link for the ABI definition is available in the documentation, but I'll add it here too.

...

+#define TS_RPC_UUID UUID_INIT(0xbdcd76d7, 0x825e, 0x4751, \

•                         0x96, 0x3b, 0x86, 0xd4, 0xf8, 0x49, 0x43, 0xac)
  

+/* Protocol version*/ +#define TS_RPC_PROTOCOL_VERSION (1)

+/* Status codes */ +#define TS_RPC_OK (0)

+/* RPC control register */ +#define TS_RPC_CTRL_REG (0) +#define OPCODE_MASK GENMASK(15, 0) +#define IFACE_ID_MASK GENMASK(23, 16) +#define TS_RPC_CTRL_OPCODE(x) ((u16)(FIELD_GET(OPCODE_MASK, (x)))) +#define TS_RPC_CTRL_IFACE_ID(x) ((u8)(FIELD_GET(IFACE_ID_MASK, (x)))) +#define TS_RPC_CTRL_PACK_IFACE_OPCODE(i, o) \

•   (FIELD_PREP(IFACE_ID_MASK, (i)) | FIELD_PREP(OPCODE_MASK, (o)))
  

+#define TS_RPC_CTRL_SAP_RC BIT(30) +#define TS_RPC_CTRL_SAP_ERR BIT(31)

+/* Interface ID for RPC management operations */ +#define TS_RPC_MGMT_IFACE_ID (0xff)

+/* Management calls */ +#define TS_RPC_OP_GET_VERSION (0x0000) +#define TS_RPC_GET_VERSION_RESP (1)

+#define TS_RPC_OP_RETRIEVE_MEM (0x0001) +#define TS_RPC_RETRIEVE_MEM_HANDLE_LSW (1) +#define TS_RPC_RETRIEVE_MEM_HANDLE_MSW (2) +#define TS_RPC_RETRIEVE_MEM_TAG_LSW (3) +#define TS_RPC_RETRIEVE_MEM_TAG_MSW (4) +#define TS_RPC_RETRIEVE_MEM_RPC_STATUS (1)

+#define TS_RPC_OP_RELINQ_MEM (0x0002) +#define TS_RPC_RELINQ_MEM_HANDLE_LSW (1) +#define TS_RPC_RELINQ_MEM_HANDLE_MSW (2) +#define TS_RPC_RELINQ_MEM_RPC_STATUS (1)

+#define TS_RPC_OP_SERVICE_INFO (0x0003) +#define TS_RPC_SERVICE_INFO_UUID0 (1) +#define TS_RPC_SERVICE_INFO_UUID1 (2) +#define TS_RPC_SERVICE_INFO_UUID2 (3) +#define TS_RPC_SERVICE_INFO_UUID3 (4) +#define TS_RPC_SERVICE_INFO_RPC_STATUS (1) +#define TS_RPC_SERVICE_INFO_IFACE (2)

+/* Service call */ +#define TS_RPC_SERVICE_MEM_HANDLE_LSW (1) +#define TS_RPC_SERVICE_MEM_HANDLE_MSW (2) +#define TS_RPC_SERVICE_REQ_LEN (3) +#define TS_RPC_SERVICE_CLIENT_ID (4) +#define TS_RPC_SERVICE_RPC_STATUS (1) +#define TS_RPC_SERVICE_STATUS (2) +#define TS_RPC_SERVICE_RESP_LEN (3)

+struct tstee {

•   struct ffa_device *ffa_dev;
  

•   struct tee_device *teedev;
  

•   struct tee_shm_pool *pool;
  

+};

+struct ts_session {

•   struct list_head list_node;
  

•   u32 session_id;
  

•   u8 iface_id;
  

+};

+struct ts_context_data {

•   struct list_head sess_list;
  

•   struct idr sess_ids;
  

Why do you need both a linked list and an IDR? Wouldn't the IDR be enough?

You're right, I added the IDR later and didn't realise this made the linked list redundant. I removed both the linked list and IDR and just use XArray instead.

Regards, Balint

...

•   /* Serializes access to this struct */
  

•   struct mutex mutex;
  

+};

+#endif /* TSTEE_PRIVATE_H */ diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h index 23e57164693c..d0430bee8292 100644 --- a/include/uapi/linux/tee.h +++ b/include/uapi/linux/tee.h @@ -56,6 +56,7 @@ */ #define TEE_IMPL_ID_OPTEE 1 #define TEE_IMPL_ID_AMDTEE 2 +#define TEE_IMPL_ID_TSTEE 3

/*

• OP-TEE specific capabilities

-- 2.34.1

Hi--

On 2/13/24 06:52, Balint Dobszay wrote:

Add documentation for the Trusted Services TEE driver.

Signed-off-by: Balint Dobszay balint.dobszay@arm.com

Documentation/tee/index.rst | 1 + Documentation/tee/ts-tee.rst | 70 ++++++++++++++++++++++++++++++++++++ 2 files changed, 71 insertions(+) create mode 100644 Documentation/tee/ts-tee.rst

diff --git a/Documentation/tee/ts-tee.rst b/Documentation/tee/ts-tee.rst new file mode 100644 index 000000000000..e121ebbbfab7 --- /dev/null +++ b/Documentation/tee/ts-tee.rst @@ -0,0 +1,70 @@ +.. SPDX-License-Identifier: GPL-2.0

+================================= +TS-TEE (Trusted Services project) +=================================

+This driver provides access to secure services implemented by Trusted Services.

+Trusted Services [1] is a TrustedFirmware.org project that provides a framework +for developing and deploying device Root of Trust services in FF-A [2] S-EL0 +Secure Partitions. The project hosts the reference implementation of the Arm +Platform Security Architecture [3] for Arm A-profile devices.

+The FF-A Secure Partitions (SP) are accessible through the FF-A driver [4] which +provides the low level communication for this driver. On top of that the Trusted +Services RPC protocol is used [5]. To use the driver from user space a reference +implementation is provided at [6], which is part of the Trusted Services client +library called libts [7].

Fix run-on sentences:

+All Trusted Services (TS) SPs have the same FF-A UUID, it identifies the TS RPC

UUID. It or UUIT; it

+protocol. A TS SP can host one or more services (e.g. PSA Crypto, PSA ITS, etc). +A service is identified by its service UUID, the same type of service cannot be

UUID;

+present twice in the same SP. During SP boot each service in the SP is assigned +an "interface ID", this is just a short ID to simplify message addressing.

"interface ID." This

+The generic TEE design is to share memory at once with the TEE implementation, +which can then be reused to communicate with multiple TAs. However, in case of

"TA" is not defined.

+FF-A, memory sharing works on an endpoint level, i.e. memory is shared with a +specific SP. User space has to be able to separately share memory with each SP +based on its endpoint ID, therefore a separate TEE device is registered for each

ID; therefore

+discovered TS SP. Opening the SP corresponds to opening the TEE device and +creating a TEE context. A TS SP hosts one or more services, opening a service

services. Opening

+corresponds to opening a session in the given tee_context.

+Overview of a system with Trusted Services components::

• User space Kernel space Secure world
• +--------+ +-------------+
• | Client | | Trusted |
• +--------+ | Services SP |

•  /\                                                    +-------------+
  

•  ||                                                          /\
  

•  ||                                                          ||
  

•  ||                                                          ||
  

•  \/                                                          \/
  

• +-------+ +----------+--------+ +-------------+
• | libts | | TEE | TS-TEE | | FF-A SPMC |
• | | | subsys | driver | | + SPMD |
• +-------+----------------+----+-----+--------+-----------+-------------+
• | Generic TEE API | | FF-A | TS RPC protocol |
• | IOCTL (TEE_IOC_*) | | driver | over FF-A |
• +-----------------------------+ +--------+-------------------------+

+References +==========

+[1] https://www.trustedfirmware.org/projects/trusted-services/

+[2] https://developer.arm.com/documentation/den0077/

+[3] https://www.arm.com/architecture/security-features/platform-security

+[4] drivers/firmware/arm_ffa/

+[5] https://trusted-services.readthedocs.io/en/v1.0.0/developer/service-access-p...

+[6] https://git.trustedfirmware.org/TS/trusted-services.git/tree/components/rpc/...

+[7] https://git.trustedfirmware.org/TS/trusted-services.git/tree/deployments/lib...