[PATCH v8 2/5] remoteproc: Add TEE support

Arnaud Pouliquen
2024-06-21T14:39:27Z

Add a remoteproc TEE (Trusted Execution Environment) driver
that will be probed by the TEE bus. If the associated Trusted
application is supported on secure part this driver offers a client
interface to load a firmware by the secure part.
This firmware could be authenticated by the secure trusted application.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
---
Updates vs previous version:
- rename tee_remoteproc.* file to rmeoteproc_tee.*,
- rename TEE_REMOTEPROC config to REMOTEPROC_TEE,
- remove "stm32" in some variable declarations,
- remove useless "remoteproc_internal.h" include,
- fix tee_rproc_ctx devm_kzalloc.
- rework module description
---
drivers/remoteproc/Kconfig | 10 +
drivers/remoteproc/Makefile | 1 +
drivers/remoteproc/remoteproc_tee.c | 446 ++++++++++++++++++++++++++++
include/linux/remoteproc.h | 4 +
include/linux/remoteproc_tee.h | 100 +++++++
5 files changed, 561 insertions(+)
create mode 100644 drivers/remoteproc/remoteproc_tee.c
create mode 100644 include/linux/remoteproc_tee.h

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index 48845dc8fa85..278f197acb90 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -365,6 +365,16 @@ config XLNX_R5_REMOTEPROC

It's safe to say N if not interested in using RPU r5f cores.

+
+config REMOTEPROC_TEE
+ tristate "Remoteproc support by a TEE application"
+ depends on OPTEE
+ help
+ Support a remote processor with a TEE application. The Trusted
+ Execution Context is responsible for loading the trusted firmware
+ image and managing the remote processor's lifecycle.
+ This can be either built-in or a loadable module.
+
endif # REMOTEPROC

endmenu
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 91314a9b43ce..b4eb37177005 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_RCAR_REMOTEPROC) += rcar_rproc.o
obj-$(CONFIG_ST_REMOTEPROC) += st_remoteproc.o
obj-$(CONFIG_ST_SLIM_REMOTEPROC) += st_slim_rproc.o
obj-$(CONFIG_STM32_RPROC) += stm32_rproc.o
+obj-$(CONFIG_REMOTEPROC_TEE) += remoteproc_tee.o
obj-$(CONFIG_TI_K3_DSP_REMOTEPROC) += ti_k3_dsp_remoteproc.o
obj-$(CONFIG_TI_K3_R5_REMOTEPROC) += ti_k3_r5_remoteproc.o
obj-$(CONFIG_XLNX_R5_REMOTEPROC) += xlnx_r5_remoteproc.o
diff --git a/drivers/remoteproc/remoteproc_tee.c b/drivers/remoteproc/remoteproc_tee.c
new file mode 100644
index 000000000000..70cb67451767
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_tee.c
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) STMicroelectronics 2024
+ * Author: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
+ */
+
+#include <linux/firmware.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/remoteproc.h>
+#include <linux/remoteproc_tee.h>
+#include <linux/slab.h>
+#include <linux/tee_drv.h>
+
+#define MAX_TEE_PARAM_ARRY_MEMBER 4
+
+/*
+ * Authentication of the firmware and load in the remote processor memory
+ *
+ * [in] params[0].value.a: unique 32bit identifier of the remote processor
+ * [in] params[1].memref: buffer containing the image of the buffer
+ */
+#define TA_RPROC_FW_CMD_LOAD_FW 1
+
+/*
+ * Start the remote processor
+ *
+ * [in] params[0].value.a: unique 32bit identifier of the remote processor
+ */
+#define TA_RPROC_FW_CMD_START_FW 2
+
+/*
+ * Stop the remote processor
+ *
+ * [in] params[0].value.a: unique 32bit identifier of the remote processor
+ */
+#define TA_RPROC_FW_CMD_STOP_FW 3
+
+/*
+ * Return the address of the resource table, or 0 if not found
+ * No check is done to verify that the address returned is accessible by
+ * the non secure context. If the resource table is loaded in a protected
+ * memory the access by the non secure context will lead to a data abort.
+ *
+ * [in] params[0].value.a: unique 32bit identifier of the remote processor
+ * [out] params[1].value.a: 32bit LSB resource table memory address
+ * [out] params[1].value.b: 32bit MSB resource table memory address
+ * [out] params[2].value.a: 32bit LSB resource table memory size
+ * [out] params[2].value.b: 32bit MSB resource table memory size
+ */
+#define TA_RPROC_FW_CMD_GET_RSC_TABLE 4
+
+/*
+ * Return the address of the core dump
+ *
+ * [in] params[0].value.a: unique 32bit identifier of the remote processor
+ * [out] params[1].memref: address of the core dump image if exist,
+ * else return Null
+ */
+#define TA_RPROC_FW_CMD_GET_COREDUMP 5
+
+struct tee_rproc_context {
+ struct list_head sessions;
+ struct tee_context *tee_ctx;
+ struct device *dev;
+};
+
+static struct tee_rproc_context *tee_rproc_ctx;
+
+static void tee_rproc_prepare_args(struct tee_rproc *trproc, int cmd,
+ struct tee_ioctl_invoke_arg *arg,
+ struct tee_param *param,
+ unsigned int num_params)
+{
+ memset(arg, 0, sizeof(*arg));
+ memset(param, 0, MAX_TEE_PARAM_ARRY_MEMBER * sizeof(*param));
+
+ arg->func = cmd;
+ arg->session = trproc->session_id;
+ arg->num_params = num_params + 1;
+
+ param[0] = (struct tee_param) {
+ .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
+ .u.value.a = trproc->rproc_id,
+ };
+}
+
+int tee_rproc_load_fw(struct rproc *rproc, const struct firmware *fw)
+{
+ struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
+ struct tee_rproc *trproc = rproc->tee_interface;
+ struct tee_ioctl_invoke_arg arg;
+ struct tee_shm *fw_shm;
+ int ret;
+
+ if (!trproc)
+ return -EINVAL;
+
+ fw_shm = tee_shm_register_kernel_buf(tee_rproc_ctx->tee_ctx, (void *)fw->data, fw->size);
+ if (IS_ERR(fw_shm))
+ return PTR_ERR(fw_shm);
+
+ tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_LOAD_FW, &arg, param, 1);
+
+ /* Provide the address of the firmware image */
+ param[1] = (struct tee_param) {
+ .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
+ .u.memref = {
+ .shm = fw_shm,
+ .size = fw->size,
+ .shm_offs = 0,
+ },
+ };
+
+ ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
+ if (ret < 0 || arg.ret != 0) {
+ dev_err(tee_rproc_ctx->dev,
+ "TA_RPROC_FW_CMD_LOAD_FW invoke failed TEE err: %x, ret:%x\n",
+ arg.ret, ret);
+ if (!ret)
+ ret = -EIO;
+ }
+
+ tee_shm_free(fw_shm);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tee_rproc_load_fw);
+
+static int tee_rproc_get_loaded_rsc_table(struct rproc *rproc, phys_addr_t *rsc_pa,
+ size_t *table_sz)
+{
+ struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
+ struct tee_rproc *trproc = rproc->tee_interface;
+ struct tee_ioctl_invoke_arg arg;
+ int ret;
+
+ tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_GET_RSC_TABLE, &arg, param, 2);
+
+ param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+ param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+ ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
+ if (ret < 0 || arg.ret != 0) {
+ dev_err(tee_rproc_ctx->dev,
+ "TA_RPROC_FW_CMD_GET_RSC_TABLE invoke failed TEE err: %x, ret:%x\n",
+ arg.ret, ret);
+ return -EIO;
+ }
+
+ *table_sz = param[2].u.value.a;
+
+ if (*table_sz)
+ *rsc_pa = param[1].u.value.a;
+ else
+ *rsc_pa = 0;
+
+ return 0;
+}
+
+int tee_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
+{
+ phys_addr_t rsc_table;
+ void __iomem *rsc_va;
+ size_t table_sz;
+ int ret;
+
+ ret = tee_rproc_load_fw(rproc, fw);
+ if (ret)
+ return ret;
+
+ ret = tee_rproc_get_loaded_rsc_table(rproc, &rsc_table, &table_sz);
+ if (ret)
+ return ret;
+
+ /*
+ * We assume here that the memory mapping is the same between the TEE and Linux kernel
+ * contexts. Else a new TEE remoteproc service could be needed to get a copy of the
+ * resource table
+ */
+ rsc_va = ioremap_wc(rsc_table, table_sz);
+ if (IS_ERR_OR_NULL(rsc_va)) {
+ dev_err(tee_rproc_ctx->dev, "Unable to map memory region: %pa+%zx\n",
+ &rsc_table, table_sz);
+ return -ENOMEM;
+ }
+
+ /*
+ * Create a copy of the resource table to have the same behavior as the elf loader.
+ * This cached table will be used after the remoteproc stops to free resources, and for
+ * crash recovery to reapply the settings.
+ */
+ rproc->cached_table = kmemdup((__force void *)rsc_va, table_sz, GFP_KERNEL);
+ if (!rproc->cached_table) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ rproc->table_ptr = rproc->cached_table;
+ rproc->table_sz = table_sz;
+
+out:
+ iounmap(rsc_va);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tee_rproc_parse_fw);
+
+struct resource_table *tee_rproc_find_loaded_rsc_table(struct rproc *rproc,
+ const struct firmware *fw)
+{
+ struct tee_rproc *trproc = rproc->tee_interface;
+ phys_addr_t rsc_table;
+ size_t table_sz;
+ int ret;
+
+ if (!trproc)
+ return ERR_PTR(-EINVAL);
+
+ ret = tee_rproc_get_loaded_rsc_table(rproc, &rsc_table, &table_sz);
+ if (ret)
+ return ERR_PTR(ret);
+
+ rproc->table_sz = table_sz;
+ if (!table_sz)
+ return NULL;
+
+ /*
+ * At this step the memory area that contains the resource table should have be declared
+ * in the remote proc platform driver and allocated by rproc_alloc_registered_carveouts().
+ */
+ return (struct resource_table *)rproc_pa_to_va(rproc, rsc_table, table_sz, NULL);
+}
+EXPORT_SYMBOL_GPL(tee_rproc_find_loaded_rsc_table);
+
+int tee_rproc_start(struct rproc *rproc)
+{
+ struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
+ struct tee_rproc *trproc = rproc->tee_interface;
+ struct tee_ioctl_invoke_arg arg;
+ int ret = 0;
+
+ if (!trproc)
+ return -EINVAL;
+
+ tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_START_FW, &arg, param, 0);
+
+ ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
+ if (ret < 0 || arg.ret != 0) {
+ dev_err(tee_rproc_ctx->dev,
+ "TA_RPROC_FW_CMD_START_FW invoke failed TEE err: %x, ret:%x\n",
+ arg.ret, ret);
+ if (!ret)
+ return -EIO;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tee_rproc_start);
+
+int tee_rproc_stop(struct rproc *rproc)
+{
+ struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
+ struct tee_rproc *trproc = rproc->tee_interface;
+ struct tee_ioctl_invoke_arg arg;
+ int ret;
+
+ if (!trproc)
+ return -EINVAL;
+
+ tee_rproc_prepare_args(trproc, TA_RPROC_FW_CMD_STOP_FW, &arg, param, 0);
+
+ ret = tee_client_invoke_func(tee_rproc_ctx->tee_ctx, &arg, param);
+ if (ret < 0 || arg.ret != 0) {
+ dev_err(tee_rproc_ctx->dev,
+ "TA_RPROC_FW_CMD_STOP_FW invoke failed TEE err: %x, ret:%x\n",
+ arg.ret, ret);
+ if (!ret)
+ ret = -EIO;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tee_rproc_stop);
+
+static const struct tee_client_device_id tee_rproc_id_table[] = {
+ {UUID_INIT(0x80a4c275, 0x0a47, 0x4905, 0x82, 0x85, 0x14, 0x86, 0xa9, 0x77, 0x1a, 0x08)},
+ {}
+};
+
+struct tee_rproc *tee_rproc_register(struct device *dev, struct rproc *rproc, unsigned int rproc_id)
+{
+ struct tee_param param[MAX_TEE_PARAM_ARRY_MEMBER];
+ struct tee_ioctl_open_session_arg sess_arg;
+ struct tee_client_device *tee_device;
+ struct tee_rproc *trproc, *p_err;
+ int ret;
+
+ /*
+ * Test if the device has been probed by the TEE bus. In case of failure, we ignore the
+ * reason. The bus could be not yet probed or the service not available in the secure
+ * firmware.The assumption in such a case is that the TEE remoteproc is not probed.
+ */
+ if (!tee_rproc_ctx)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ /* Prevent tee rproc module from being removed */
+ if (!try_module_get(THIS_MODULE)) {
+ dev_err(tee_rproc_ctx->dev, "can't get owner\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ trproc = devm_kzalloc(dev, sizeof(*trproc), GFP_KERNEL);
+ if (!trproc) {
+ p_err = ERR_PTR(-ENOMEM);
+ goto module_put;
+ }
+ tee_device = to_tee_client_device(tee_rproc_ctx->dev);
+ memset(&sess_arg, 0, sizeof(sess_arg));
+
+ memcpy(sess_arg.uuid, tee_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
+
+ sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+ sess_arg.num_params = 1;
+
+ param[0] = (struct tee_param) {
+ .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
+ .u.value.a = rproc_id,
+ };
+
+ ret = tee_client_open_session(tee_rproc_ctx->tee_ctx, &sess_arg, param);
+ if (ret < 0 || sess_arg.ret != 0) {
+ dev_err(dev, "tee_client_open_session failed, err: %x\n", sess_arg.ret);
+ p_err = ERR_PTR(-EINVAL);
+ goto module_put;
+ }
+
+ trproc->parent = dev;
+ trproc->rproc_id = rproc_id;
+ trproc->session_id = sess_arg.session;
+
+ trproc->rproc = rproc;
+ rproc->tee_interface = trproc;
+
+ list_add_tail(&trproc->node, &tee_rproc_ctx->sessions);
+
+ return trproc;
+
+module_put:
+ module_put(THIS_MODULE);
+ return p_err;
+}
+EXPORT_SYMBOL_GPL(tee_rproc_register);
+
+int tee_rproc_unregister(struct tee_rproc *trproc)
+{
+ struct rproc *rproc = trproc->rproc;
+ int ret;
+
+ ret = tee_client_close_session(tee_rproc_ctx->tee_ctx, trproc->session_id);
+ if (ret < 0)
+ dev_err(trproc->parent, "tee_client_close_session failed, err: %x\n", ret);
+
+ list_del(&trproc->node);
+ rproc->tee_interface = NULL;
+
+ module_put(THIS_MODULE);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tee_rproc_unregister);
+
+static int tee_rproc_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+ /* Today we support only the OP-TEE, could be extend to other tees */
+ return (ver->impl_id == TEE_IMPL_ID_OPTEE);
+}
+
+static int tee_rproc_probe(struct device *dev)
+{
+ struct tee_context *tee_ctx;
+ int ret;
+
+ /* Open context with TEE driver */
+ tee_ctx = tee_client_open_context(NULL, tee_rproc_ctx_match, NULL, NULL);
+ if (IS_ERR(tee_ctx))
+ return PTR_ERR(tee_ctx);
+
+ tee_rproc_ctx = devm_kzalloc(dev, sizeof(*tee_rproc_ctx), GFP_KERNEL);
+ if (!tee_rproc_ctx) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ tee_rproc_ctx->dev = dev;
+ tee_rproc_ctx->tee_ctx = tee_ctx;
+ INIT_LIST_HEAD(&tee_rproc_ctx->sessions);
+
+ return 0;
+err:
+ tee_client_close_context(tee_ctx);
+
+ return ret;
+}
+
+static int tee_rproc_remove(struct device *dev)
+{
+ struct tee_rproc *entry, *tmp;
+
+ list_for_each_entry_safe(entry, tmp, &tee_rproc_ctx->sessions, node) {
+ tee_client_close_session(tee_rproc_ctx->tee_ctx, entry->session_id);
+ list_del(&entry->node);
+ kfree(entry);
+ }
+
+ tee_client_close_context(tee_rproc_ctx->tee_ctx);
+
+ return 0;
+}
+
+MODULE_DEVICE_TABLE(tee, tee_rproc_id_table);
+
+static struct tee_client_driver tee_rproc_fw_driver = {
+ .id_table = tee_rproc_id_table,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .bus = &tee_bus_type,
+ .probe = tee_rproc_probe,
+ .remove = tee_rproc_remove,
+ },
+};
+
+static int __init tee_rproc_fw_mod_init(void)
+{
+ return driver_register(&tee_rproc_fw_driver.driver);
+}
+
+static void __exit tee_rproc_fw_mod_exit(void)
+{
+ driver_unregister(&tee_rproc_fw_driver.driver);
+}
+
+module_init(tee_rproc_fw_mod_init);
+module_exit(tee_rproc_fw_mod_exit);
+
+MODULE_DESCRIPTION(" remote processor support with a TEE application");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 8fd0d7f63c8e..fbe1d6793709 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -503,6 +503,8 @@ enum rproc_features {
RPROC_MAX_FEATURES,
};

+struct tee_rproc;
+
/**
* struct rproc - represents a physical remote processor device
* @node: list node of this rproc object
@@ -545,6 +547,7 @@ enum rproc_features {
* @cdev: character device of the rproc
* @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release
* @features: indicate remoteproc features
+ * @tee_interface: pointer to the remoteproc tee context
*/
struct rproc {
struct list_head node;
@@ -586,6 +589,7 @@ struct rproc {
struct cdev cdev;
bool cdev_put_on_release;
DECLARE_BITMAP(features, RPROC_MAX_FEATURES);
+ struct tee_rproc *tee_interface;
};

/**
diff --git a/include/linux/remoteproc_tee.h b/include/linux/remoteproc_tee.h
new file mode 100644
index 000000000000..ccf34a218d54
--- /dev/null
+++ b/include/linux/remoteproc_tee.h
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright(c) 2024 STMicroelectronics
+ */
+
+#ifndef REMOTEPROC_TEE_H
+#define REMOTEPROC_TEE_H
+
+#include <linux/tee_drv.h>
+#include <linux/firmware.h>
+#include <linux/remoteproc.h>
+
+struct rproc;
+
+/**
+ * struct tee_rproc - TEE remoteproc structure
+ * @node: Reference in list
+ * @rproc: Remoteproc reference
+ * @parent: Parent device
+ * @rproc_id: Identifier of the target firmware
+ * @session_id: TEE session identifier
+ */
+struct tee_rproc {
+ struct list_head node;
+ struct rproc *rproc;
+ struct device *parent;
+ u32 rproc_id;
+ u32 session_id;
+};
+
+#if IS_REACHABLE(CONFIG_REMOTEPROC_TEE)
+
+struct tee_rproc *tee_rproc_register(struct device *dev, struct rproc *rproc,
+ unsigned int rproc_id);
+int tee_rproc_unregister(struct tee_rproc *trproc);
+int tee_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw);
+int tee_rproc_load_fw(struct rproc *rproc, const struct firmware *fw);
+struct resource_table *tee_rproc_find_loaded_rsc_table(struct rproc *rproc,
+ const struct firmware *fw);
+int tee_rproc_start(struct rproc *rproc);
+int tee_rproc_stop(struct rproc *rproc);
+
+#else
+
+static inline struct tee_rproc *tee_rproc_register(struct device *dev, struct rproc *rproc,
+ unsigned int rproc_id)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+static int tee_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
+{
+ /* This shouldn't be possible */
+ WARN_ON(1);
+
+ return 0;
+}
+
+static inline int tee_rproc_unregister(struct tee_rproc *trproc)
+{
+ /* This shouldn't be possible */
+ WARN_ON(1);
+
+ return 0;
+}
+
+static inline int tee_rproc_load_fw(struct rproc *rproc, const struct firmware *fw)
+{
+ /* This shouldn't be possible */
+ WARN_ON(1);
+
+ return 0;
+}
+
+static inline int tee_rproc_start(struct rproc *rproc)
+{
+ /* This shouldn't be possible */
+ WARN_ON(1);
+
+ return 0;
+}
+
+static inline int tee_rproc_stop(struct rproc *rproc)
+{
+ /* This shouldn't be possible */
+ WARN_ON(1);
+
+ return 0;
+}
+
+static inline struct resource_table *
+tee_rproc_find_loaded_rsc_table(struct rproc *rproc, const struct firmware *fw)
+{
+ /* This shouldn't be possible */
+ WARN_ON(1);
+
+ return NULL;
+}
+#endif /* CONFIG_REMOTEPROC_TEE */
+#endif /* REMOTEPROC_TEE_H */
--
2.25.1