settings: tfm_psa: rename from its

Prepare for extending this backend to also allow storing settings in the
PS (Protected Storage).

Mostly file and kconfig renames, as well as updates
to comments and log messages.

Signed-off-by: Dmitrii Sharshakov <[email protected]>

Author: dsseng

include/zephyr/psa/its_ids.h

@@ -3,11 +3,11 @@
  *
  * SPDX-License-Identifier: Apache-2.0
  */
-#ifndef ZEPHYR_ITS_IDS_H_
-#define ZEPHYR_ITS_IDS_H_
+#ifndef ZEPHYR_PSA_ITS_IDS_H_
+#define ZEPHYR_PSA_ITS_IDS_H_
 
-/** UID range to be used by the TF-M ITS Settings backend. */
+/** UID range to be used by the TF-M PSA ITS Settings backend. */
 #define ZEPHYR_PSA_SETTINGS_TFM_ITS_UID_RANGE_BEGIN 0x28000000
 #define ZEPHYR_PSA_SETTINGS_TFM_ITS_UID_RANGE_SIZE  0x10000 /* 64 Ki */
 
-#endif /* ZEPHYR_ITS_IDS_H_ */
+#endif /* ZEPHYR_PSA_ITS_IDS_H_ */

samples/subsys/settings/sample.yaml

@@ -63,4 +63,4 @@ tests:
     integration_platforms:
       - mps2/an521/cpu0/ns
     extra_args:
-      - CONFIG_SETTINGS_TFM_ITS=y
+      - CONFIG_SETTINGS_TFM_PSA=y

subsys/settings/Kconfig

@@ -143,17 +143,19 @@ config SETTINGS_CUSTOM
 	help
 	  Use a custom settings storage back-end.
 
-config SETTINGS_TFM_ITS
-	bool "Internal Trusted Storage (ITS) settings backend"
+config SETTINGS_TFM_PSA
+	bool "TF-M PSA"
 	depends on TFM_PARTITION_INTERNAL_TRUSTED_STORAGE
 	select EXPERIMENTAL
 	help
-	  Enables Internal Trusted Storage (ITS) Settings backend. Intended for use with boards
+	  Enables PSA Settings backend. Intended for use with boards
 	  using TF-M which cannot make use of persistent storage otherwise.
-	  Note: This settings backend compacts settings data into as few ITS nodes as possible.
-	  On every save, the entire settings array is written to ITS.
+	  This backend uses the PSA Internal Trusted Storage (ITS) service to store settings data.
+	  Note: This settings backend compacts settings data into as few secure storage nodes as possible.
+	  After each save, the entire settings array is written to the secure storage. To avoid excessive
+	  latency on saving, settings are saved after a delay using a kernel work item.
 	  Note: With this backend, all settings are kept in RAM at all times. The RAM consumption
-	  is controlled by the SETTINGS_TFM_ITS_NUM_ENTRIES Kconfig option.
+	  is controlled by the SETTINGS_TFM_PSA_NUM_ENTRIES Kconfig option.
 
 config SETTINGS_NONE
 	bool "NONE"
@@ -265,28 +267,28 @@ config SETTINGS_SHELL
 	  size of the shell thread may need to be increased to accommodate this
 	  feature.
 
-if SETTINGS_TFM_ITS
+if SETTINGS_TFM_PSA
 
-config SETTINGS_TFM_ITS_NUM_ENTRIES
+config SETTINGS_TFM_PSA_NUM_ENTRIES
 	int "Maximum number of settings entries"
 	default 10
 	help
 	  Configures the maximum number of settings that can be stored simultaneously.
 	  Note: This value determines the size of a statically-allocated buffer which holds
 	  all the settings entries in RAM at all times.
 
-config SETTINGS_TFM_ITS_LAZY_PERSIST_DELAY_MS
+config SETTINGS_TFM_PSA_LAZY_PERSIST_DELAY_MS
 	int "Milliseconds delay before persisting settings"
 	default 500
 	help
-	  ITS may block for a long period of time when writing to flash, which may be
+	  PSA Secure Storage APIs may block for a long period of time when writing to flash, which may be
 	  unacceptable for time-sensitive events.
-	  Data is always persisted to ITS using k_work_delayable, instead of happening in
-	  the same context as settings_its_save. This option sets the delay with which the
+	  Data is always persisted to the secure storage using k_work_delayable, instead of happening in
+	  the same context as settings_save. This option sets the delay with which the
 	  work item is scheduled. The delay is useful in cases where a PSA ITS write may
-	  block a time-sensitive event, Bluetooth pairing for example, which requires a
+	  block a time-sensitive event, for example Bluetooth pairing, which requires a
 	  sequence of settings writes.
 
-endif # SETTINGS_TFM_ITS
+endif # SETTINGS_TFM_PSA
 
 endif # SETTINGS

subsys/settings/src/CMakeLists.txt

@@ -14,6 +14,8 @@ zephyr_sources_ifdef(CONFIG_SETTINGS_NVS settings_nvs.c)
 zephyr_sources_ifdef(CONFIG_SETTINGS_NONE settings_none.c)
 zephyr_sources_ifdef(CONFIG_SETTINGS_SHELL settings_shell.c)
 zephyr_sources_ifdef(CONFIG_SETTINGS_ZMS settings_zms.c)
-zephyr_sources_ifdef(CONFIG_SETTINGS_TFM_ITS settings_its.c)
-zephyr_library_link_libraries_ifdef(CONFIG_SETTINGS_TFM_ITS tfm_api)
+if(CONFIG_SETTINGS_TFM_PSA)
+  zephyr_sources(settings_tfm_psa.c)
+  zephyr_library_link_libraries(tfm_api)
+endif()
 zephyr_sources_ifdef(CONFIG_SETTINGS_RETENTION settings_retention.c)

subsys/settings/src/settings_its.c subsys/settings/src/settings_tfm_psa.csubsys/settings/src/settings_its.c renamed to subsys/settings/src/settings_tfm_psa.c

@@ -15,29 +15,30 @@
 /* TF-M config file containing ITS_MAX_ASSET_SIZE */
 #include <config_base.h>
 
-#include "settings_its_priv.h"
+#include "settings_tfm_psa_priv.h"
 
 LOG_MODULE_DECLARE(settings, CONFIG_SETTINGS_LOG_LEVEL);
 
 K_MUTEX_DEFINE(worker_mutex);
 static struct k_work_delayable worker;
 
-static struct setting_entry entries[CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES];
+static struct setting_entry entries[CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES];
 static int entries_count;
 
-static int settings_its_load(struct settings_store *cs, const struct settings_load_arg *arg);
-static int settings_its_save(struct settings_store *cs, const char *name, const char *value,
+static int settings_psa_load(struct settings_store *cs, const struct settings_load_arg *arg);
+static int settings_psa_save(struct settings_store *cs, const char *name, const char *value,
 			     size_t val_len);
 
-static const struct settings_store_itf settings_its_itf = {
-	.csi_load = settings_its_load,
-	.csi_save = settings_its_save,
+static const struct settings_store_itf settings_psa_itf = {
+	.csi_load = settings_psa_load,
+	.csi_save = settings_psa_save,
 };
 
-static struct settings_store default_settings_its = {.cs_itf = &settings_its_itf};
+static struct settings_store default_settings_psa = {.cs_itf = &settings_psa_itf};
 
 /* Ensure Key configured max size does not exceed reserved Key range */
-BUILD_ASSERT(sizeof(entries) / ITS_MAX_ASSET_SIZE <= ZEPHYR_PSA_SETTINGS_TFM_ITS_UID_RANGE_SIZE,
+BUILD_ASSERT(sizeof(entries) / ITS_MAX_ASSET_SIZE <=
+	     ZEPHYR_PSA_SETTINGS_TFM_ITS_UID_RANGE_BEGIN,
 	     "entries array exceeds reserved ITS UID range");
 
 static int store_entries(void)
@@ -49,9 +50,9 @@ static int store_entries(void)
 	const uint8_t *data_ptr = (const uint8_t *)&entries;
 
 	/*
-	 * Each ITS UID is treated like a sector. Data is written to each ITS node until
-	 * that node is full, before incrementing the UID. This is done to minimize the
-	 * number of allocated ITS nodes and to avoid wasting allocated bytes.
+	 * Each storage UID is treated like a sector. Data is written to each KV pair until
+	 * that data field is full, before incrementing the UID. This is done to minimize the
+	 * number of allocated UIDs and to allocate bytes in the most efficient way.
 	 */
 	while (remaining > 0) {
 		size_t write_size = (remaining > chunk_size) ? chunk_size : remaining;
@@ -69,7 +70,7 @@ static int store_entries(void)
 		uid++;
 	}
 
-	LOG_DBG("ITS entries stored successfully - bytes_saved: %d num_entries: %d max_uid: %lld",
+	LOG_DBG("PSA storage entries stored successfully - bytes_saved: %d num_entries: %d max_uid: %lld",
 		sizeof(entries), entries_count, uid);
 
 	return 0;
@@ -85,9 +86,9 @@ static int load_entries(void)
 	uint8_t *data_ptr = (uint8_t *)&entries;
 
 	/*
-	 * Each ITS UID is treated like a sector. Data is written to each ITS node until
-	 * that node is full, before incrementing the UID. This is done to minimize the
-	 * number of allocated ITS nodes and to avoid wasting allocated bytes.
+	 * Each storage UID is treated like a sector. Data is written to each KV pair until
+	 * that data field is full, before incrementing the UID. This is done to minimize the
+	 * number of allocated UIDs and to allocate bytes in the most efficient way.
 	 */
 	while (remaining > 0) {
 		size_t to_read = (remaining > chunk_size) ? chunk_size : remaining;
@@ -102,27 +103,27 @@ static int load_entries(void)
 		uid++;
 	}
 
-	for (int i = 0; i < CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES; i++) {
+	for (int i = 0; i < CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES; i++) {
 		if (strnlen(entries[i].name, SETTINGS_MAX_NAME_LEN) != 0) {
 			entries_count++;
 		}
 	}
 
-	LOG_DBG("ITS entries restored successfully - bytes_loaded: %d, num_entries: %d",
+	LOG_DBG("PSA storage entries restored successfully - bytes_loaded: %d, num_entries: %d",
 		sizeof(entries), entries_count);
 
 	return 0;
 }
 
 /* void *back_end is the index of the entry in metadata entries struct */
-static ssize_t settings_its_read_fn(void *back_end, void *data, size_t len)
+static ssize_t settings_psa_read_fn(void *back_end, void *data, size_t len)
 {
 	int index = *(int *)back_end;
 
-	LOG_DBG("ITS Read - index: %d", index);
+	LOG_DBG("reading index: %d", index);
 
-	if (index < 0 || index >= CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES) {
-		LOG_ERR("Invalid index %d in ITS metadata", index);
+	if (index < 0 || index >= CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES) {
+		LOG_ERR("Invalid index %d in metadata", index);
 		return 0;
 	}
 
@@ -134,7 +135,7 @@ static ssize_t settings_its_read_fn(void *back_end, void *data, size_t len)
 	return entries[index].val_len;
 }
 
-static int settings_its_load(struct settings_store *cs, const struct settings_load_arg *arg)
+static int settings_psa_load(struct settings_store *cs, const struct settings_load_arg *arg)
 {
 	int ret;
 
@@ -145,7 +146,7 @@ static int settings_its_load(struct settings_store *cs, const struct settings_lo
 			 * to be read during callback function later.
 			 */
 			ret = settings_call_set_handler(entries[i].name, entries[i].val_len,
-							settings_its_read_fn, (void *)&i,
+							settings_psa_read_fn, (void *)&i,
 							(void *)arg);
 			if (ret) {
 				return ret;
@@ -156,12 +157,12 @@ static int settings_its_load(struct settings_store *cs, const struct settings_lo
 	return 0;
 }
 
-static int settings_its_save(struct settings_store *cs, const char *name, const char *value,
+static int settings_psa_save(struct settings_store *cs, const char *name, const char *value,
 			     size_t val_len)
 {
-	if (entries_count >= CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES) {
+	if (entries_count >= CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES) {
 		LOG_ERR("%s: Max settings reached: %d", __func__,
-			CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES);
+			CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES);
 		return -ENOMEM;
 	}
 
@@ -183,7 +184,7 @@ static int settings_its_save(struct settings_store *cs, const char *name, const
 	 * Search metadata to see if entry already exists. Array is compacted, so first blank entry
 	 * signals end of settings.
 	 */
-	for (index = 0; index < CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES; index++) {
+	for (index = 0; index < CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES; index++) {
 		if (strncmp(entries[index].name, name, SETTINGS_MAX_NAME_LEN) == 0) {
 			break;
 		} else if (entries[index].val_len == 0) {
@@ -201,7 +202,7 @@ static int settings_its_save(struct settings_store *cs, const char *name, const
 		}
 	}
 
-	LOG_DBG("ITS Save - index %d: name %s, val_len %d", index, name, val_len);
+	LOG_DBG("writing index %d: name %s, val_len %d", index, name, val_len);
 
 	if (delete) {
 		/* Clear metadata */
@@ -226,7 +227,7 @@ static int settings_its_save(struct settings_store *cs, const char *name, const
 	}
 
 	k_mutex_unlock(&worker_mutex);
-	k_work_schedule(&worker, K_MSEC(CONFIG_SETTINGS_TFM_ITS_LAZY_PERSIST_DELAY_MS));
+	k_work_schedule(&worker, K_MSEC(CONFIG_SETTINGS_TFM_PSA_LAZY_PERSIST_DELAY_MS));
 
 	return 0;
 }
@@ -242,7 +243,7 @@ int settings_backend_init(void)
 {
 	psa_status_t status;
 
-	/* Load ITS metadata */
+	/* Load settings from storage */
 	status = load_entries();
 
 	/* If resource DNE, we need to allocate it */
@@ -257,8 +258,8 @@ int settings_backend_init(void)
 		return -EIO;
 	}
 
-	settings_dst_register(&default_settings_its);
-	settings_src_register(&default_settings_its);
+	settings_dst_register(&default_settings_psa);
+	settings_src_register(&default_settings_psa);
 
 	k_work_init_delayable(&worker, worker_persist_entries_struct_fn);
 

subsys/settings/src/settings_its_priv.h …sys/settings/src/settings_tfm_psa_priv.hsubsys/settings/src/settings_its_priv.h renamed to subsys/settings/src/settings_tfm_psa_priv.h subsys/settings/src/settings_its_priv.h renamed to subsys/settings/src/settings_tfm_psa_priv.h

@@ -24,13 +24,14 @@ LOG_MODULE_REGISTER(settings_basic_test);
 #elif defined(CONFIG_SETTINGS_FILE)
 #include <zephyr/fs/fs.h>
 #include <zephyr/fs/littlefs.h>
-#elif defined(CONFIG_SETTINGS_TFM_ITS)
+#elif defined(CONFIG_SETTINGS_TFM_PSA)
+
 #include <psa/internal_trusted_storage.h>
 #include <zephyr/psa/its_ids.h>
 /* TF-M config file containing ITS_MAX_ASSET_SIZE */
 #include <config_base.h>
 
-#include <settings_its_priv.h>
+#include <settings_tfm_psa_priv.h>
 #else
 #error "Settings backend not selected"
 #endif
@@ -45,14 +46,14 @@ LOG_MODULE_REGISTER(settings_basic_test);
  */
 ZTEST(settings_functional, test_clear_settings)
 {
-#if defined(CONFIG_SETTINGS_TFM_ITS)
+#if defined(CONFIG_SETTINGS_TFM_PSA)
 	psa_status_t status;
 
 	/* Remove all potentially accessed ITS entries in the UID range */
-	for (int i = 0; i < sizeof(struct setting_entry) * CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES /
+	for (int i = 0; i < sizeof(struct setting_entry) * CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES /
 		ITS_MAX_ASSET_SIZE + 1; i++) {
 		status = psa_its_remove(ZEPHYR_PSA_SETTINGS_TFM_ITS_UID_RANGE_BEGIN + i);
-		zassert_true(status == PSA_SUCCESS || status == PSA_ERROR_DOES_NOT_EXIST,
+		zassert_true((status == PSA_SUCCESS) || (status == PSA_ERROR_DOES_NOT_EXIST),
 			"psa_its_remove failed");
 	}
 #elif !defined(CONFIG_SETTINGS_FILE)

tests/subsys/settings/functional/src/settings_basic_test.c

@@ -3,4 +3,4 @@ CONFIG_ZTEST=y
 CONFIG_SETTINGS=y
 
 # 10 is not sufficient for the test
-CONFIG_SETTINGS_TFM_ITS_NUM_ENTRIES=11
+CONFIG_SETTINGS_TFM_PSA_NUM_ENTRIES=11

tests/subsys/settings/functional/tfm_psa/prj.conf

@@ -13,4 +13,4 @@ tests:
       - settings
       - trusted-firmware-m
     extra_args:
-      - CONFIG_SETTINGS_TFM_ITS=y
+      - CONFIG_SETTINGS_TFM_PSA=y

tests/subsys/settings/functional/tfm_psa/testcase.yaml

@@ -4,6 +4,6 @@
 
 cmake_minimum_required(VERSION 3.20.0)
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(test_settings_its_raw)
+project(test_settings_psa)
 
-add_subdirectory(./src its_test_bindir)
+add_subdirectory(./src psa_test_bindir)