From ee4540c46c2a1c9bead87862dd7bcaee9a7efa20 Mon Sep 17 00:00:00 2001
From: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Date: Tue, 21 Nov 2023 17:22:40 +0100
Subject: [PATCH] llext: remove llext list scanning from shell.c

The llext list should be internal to llext.c, remove its scanning
from shell.c, export a function for that instead.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
---
 include/zephyr/llext/llext.h | 13 ++++++++
 subsys/llext/llext.c         | 20 ++++++++++++
 subsys/llext/shell.c         | 60 +++++++++++++++++++++---------------
 3 files changed, 69 insertions(+), 24 deletions(-)

diff --git a/include/zephyr/llext/llext.h b/include/zephyr/llext/llext.h
index c097ec2b329..b3897bd5e05 100644
--- a/include/zephyr/llext/llext.h
+++ b/include/zephyr/llext/llext.h
@@ -91,6 +91,19 @@ sys_slist_t *llext_list(void);
  */
 struct llext *llext_by_name(const char *name);
 
+/**
+ * @brief Iterate overall registered llext instances
+ *
+ * Calls a provided callback function for each registered extension or until the
+ * callback function returns a non-0 value.
+ *
+ * @param[in] fn callback function
+ * @param[in] arg a private argument to be provided to the callback function
+ * @retval 0 if no extensions are registered
+ * @retval value returned by the most recent callback invocation
+ */
+int llext_iterate(int (*fn)(struct llext *ext, void *arg), void *arg);
+
 /**
  * @brief llext loader parameters
  *
diff --git a/subsys/llext/llext.c b/subsys/llext/llext.c
index 15436bb43ab..3d711af957d 100644
--- a/subsys/llext/llext.c
+++ b/subsys/llext/llext.c
@@ -72,6 +72,26 @@ struct llext *llext_by_name(const char *name)
 	return NULL;
 }
 
+int llext_iterate(int (*fn)(struct llext *ext, void *arg), void *arg)
+{
+	sys_snode_t *node;
+	unsigned int i;
+	int ret = 0;
+
+	for (node = sys_slist_peek_head(&_llext_list), i = 0;
+	     node;
+	     node = sys_slist_peek_next(node), i++) {
+		struct llext *ext = CONTAINER_OF(node, struct llext, _llext_list);
+
+		ret = fn(ext, arg);
+		if (ret) {
+			break;
+		}
+	}
+
+	return ret;
+}
+
 const void * const llext_find_sym(const struct llext_symtable *sym_table, const char *sym_name)
 {
 	if (sym_table == NULL) {
diff --git a/subsys/llext/shell.c b/subsys/llext/shell.c
index 0e3448d6637..57f5b1d131b 100644
--- a/subsys/llext/shell.c
+++ b/subsys/llext/shell.c
@@ -52,45 +52,57 @@ static int cmd_llext_list_symbols(const struct shell *sh, size_t argc, char *arg
 	return 0;
 }
 
-static void llext_name_get(size_t idx, struct shell_static_entry *entry)
+struct llext_shell_cmd {
+	unsigned int tgt;
+	unsigned int idx;
+	struct llext *ext;
+};
+
+static int llext_shell_name_cb(struct llext *ext, void *arg)
 {
-	sys_slist_t *ext_list = llext_list();
-	sys_snode_t *node = sys_slist_peek_head(ext_list);
+	struct llext_shell_cmd *cmd = arg;
 
-	entry->syntax = NULL;
-
-	for (int i = 0; i < idx; i++) {
-		node = sys_slist_peek_next(node);
-
-		if (node == NULL) {
-			goto out;
-		}
+	if (cmd->tgt == cmd->idx) {
+		cmd->ext = ext;
+		return 1;
 	}
 
-	struct llext *ext = CONTAINER_OF(node, struct llext, _llext_list);
+	cmd->idx++;
 
-	entry->syntax = ext->name;
-out:
-	entry->syntax = NULL;
+	return 0;
+}
+
+static void llext_name_get(size_t idx, struct shell_static_entry *entry)
+{
+	struct llext_shell_cmd cmd = {.tgt = idx};
+
+	llext_iterate(llext_shell_name_cb, &cmd);
+
+	entry->syntax = cmd.ext ? cmd.ext->name : NULL;
 	entry->help = NULL;
 	entry->subcmd = NULL;
-
 }
 
 SHELL_DYNAMIC_CMD_CREATE(msub_llext_name, llext_name_get);
 
+struct llext_shell_list {
+	const struct shell *sh;
+};
+
+static int llext_shell_list_cb(struct llext *ext, void *arg)
+{
+	struct llext_shell_list *sl = arg;
+
+	shell_print(sl->sh, "| %16s | %12d |", ext->name, ext->mem_size);
+	return 0;
+}
+
 static int cmd_llext_list(const struct shell *sh, size_t argc, char *argv[])
 {
-	sys_snode_t *node;
-	struct llext *ext;
+	struct llext_shell_list sl = {.sh = sh};
 
 	shell_print(sh, "| Name             | Size         |");
-	SYS_SLIST_FOR_EACH_NODE(llext_list(), node) {
-		ext = CONTAINER_OF(node, struct llext, _llext_list);
-		shell_print(sh, "| %16s | %12d |", ext->name, ext->mem_size);
-	}
-
-	return 0;
+	return llext_iterate(llext_shell_list_cb, &sl);
 }
 
 static uint8_t llext_buf[CONFIG_LLEXT_SHELL_MAX_SIZE];