drivers: tee: Add Tee driver generic API

Implementation of the generic API Trusted Execution Environment driver.
This implements all basic syscalls, needed by tee driver, basic
defines and helpers to work with shared memory.

Signed-off-by: Oleksii Moisieiev <[email protected]>

Author: oleksiimoisieiev

drivers/CMakeLists.txt

@@ -82,6 +82,7 @@ add_subdirectory_ifdef(CONFIG_SMBUS smbus)
 add_subdirectory_ifdef(CONFIG_SPI spi)
 add_subdirectory_ifdef(CONFIG_SYSCON syscon)
 add_subdirectory_ifdef(CONFIG_SYS_CLOCK_EXISTS timer)
+add_subdirectory_ifdef(CONFIG_TEE tee)
 add_subdirectory_ifdef(CONFIG_VIDEO video)
 add_subdirectory_ifdef(CONFIG_VIRTUALIZATION virtualization)
 add_subdirectory_ifdef(CONFIG_W1 w1)

drivers/Kconfig

@@ -90,4 +90,6 @@ source "drivers/wifi/Kconfig"
 source "drivers/xen/Kconfig"
 # zephyr-keep-sorted-stop
 
+source "drivers/tee/Kconfig"
+
 endmenu

drivers/tee/CMakeLists.txt

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: Apache-2.0
+
+if (CONFIG_TEE)
+zephyr_library()
+zephyr_library_sources(tee.c)
+endif()

drivers/tee/Kconfig

@@ -0,0 +1,16 @@
+# Copyright (c) 2023 EPAM Systems
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig TEE
+	bool "Trusted Environment Drivers"
+	help
+	  Include TEE drivers in system config
+
+if TEE
+
+module = TEE
+module-str = tee
+
+comment "Device Drivers"
+
+endif # TEE

drivers/tee/tee.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2023 EPAM Systems
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/drivers/tee.h>
+
+int tee_add_shm(const struct device *dev, void *addr, size_t align, size_t size,
+		uint32_t flags, struct tee_shm **shmp)
+{
+	int rc;
+	void *p = addr;
+	struct tee_shm *shm;
+
+	if (!shmp) {
+		return -EINVAL;
+	}
+
+	if (flags & TEE_SHM_ALLOC) {
+		if (align) {
+			p = k_aligned_alloc(align, size);
+		} else {
+			p = k_malloc(size);
+		}
+	}
+
+	if (!p) {
+		return -ENOMEM;
+	}
+
+	shm = k_malloc(sizeof(struct tee_shm));
+	if (!shm) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	shm->addr = p;
+	shm->size = size;
+	shm->flags = flags;
+	shm->dev = dev;
+
+	if (flags & TEE_SHM_REGISTER) {
+		const struct tee_driver_api *api = (const struct tee_driver_api *)dev->api;
+
+		if (!api->shm_register) {
+			rc = -ENOSYS;
+			goto err;
+		}
+
+		rc = api->shm_register(dev, shm);
+		if (rc) {
+			goto err;
+		}
+	}
+
+	*shmp = shm;
+
+	return 0;
+err:
+	k_free(shm);
+	if (flags & TEE_SHM_ALLOC) {
+		k_free(p);
+	}
+
+	return rc;
+}
+
+int tee_rm_shm(const struct device *dev, struct tee_shm *shm)
+{
+	int rc = 0;
+
+	if (!shm) {
+		return -EINVAL;
+	}
+
+	if (shm->flags & TEE_SHM_REGISTER) {
+		const struct tee_driver_api *api = (const struct tee_driver_api *)dev->api;
+
+		if (api->shm_unregister) {
+			/*
+			 * We don't return immediately if callback returned error,
+			 * just return this code after cleanup.
+			 */
+			rc = api->shm_unregister(dev, shm);
+		} else {
+			/*
+			 * Set ENOSYS is SHM_REGISTER flag was set, but callback
+			 * is not set.
+			 */
+			rc = -ENOSYS;
+		}
+	}
+
+	if (shm->flags & TEE_SHM_ALLOC) {
+		k_free(shm->addr);
+	}
+
+	k_free(shm);
+
+	return rc;
+}