llext: dynamic heap support for harvard arch

Adds support for LLEXT_HEAP_DYNAMIC with Harvard architecture.

Signed-off-by: Lauren Murphy <[email protected]>

Author: laurenmurphyx64

doc/services/llext/config.rst

@@ -57,6 +57,10 @@ option.
    large enough to allow the extension sections to be allocated with the
    alignment required by the architecture.
 
+.. note::
+   On Harvard architectures, applications must call
+   :c:func:`llext_heap_init_harvard`.
+
 .. _llext_kconfig_type:
 
 ELF object type

include/zephyr/llext/llext.h

@@ -408,10 +408,27 @@ int llext_get_section_header(struct llext_loader *loader, struct llext *ext,
  * @param bytes Size of memory region, in bytes
  *
  * @returns 0 on success, or a negative error code.
- * @retval -ENOSYS Option @kconfig{CONFIG_LLEXT_HEAP_DYNAMIC} is not enabled or supported
+ * @retval -ENOSYS Option @kconfig{CONFIG_LLEXT_HEAP_DYNAMIC} is not enabled or supported,
+ *         or it is and option @kconfig{CONFIG_HARVARD} is enabled
  */
 int llext_heap_init(void *mem, size_t bytes);
 
+/**
+ * @brief Initialize LLEXT heap dynamically for Harvard architecture
+ *
+ * Use the provided memory blocks as the LLEXT heaps at runtime.
+ *
+ * @param instr_mem Pointer to instruction memory.
+ * @param instr_bytes Size of instruction memory region, in bytes
+ * @param data_mem Pointer to data memory.
+ * @param data_bytes Size of data memory region, in bytes
+ *
+ * @returns 0 on success, or a negative error code.
+ * @retval -ENOSYS Option @kconfig{CONFIG_LLEXT_HEAP_DYNAMIC} is not enabled or supported,
+ *         or it is and option @kconfig{CONFIG_HARVARD} is not enabled
+ */
+int llext_heap_init_harvard(void *instr_mem, size_t instr_bytes, void *data_mem, size_t data_bytes);
+
 /**
  * @brief Mark LLEXT heap as uninitialized.
  *

subsys/llext/llext_mem.c

@@ -28,7 +28,12 @@ LOG_MODULE_DECLARE(llext, CONFIG_LLEXT_LOG_LEVEL);
 #endif
 
 #ifdef CONFIG_LLEXT_HEAP_DYNAMIC
+#ifdef CONFIG_HARVARD
+struct k_heap llext_instr_heap;
+struct k_heap llext_data_heap;
+#else
 struct k_heap llext_heap;
+#endif
 bool llext_heap_inited;
 #else
 #ifdef CONFIG_HARVARD
@@ -343,17 +348,36 @@ int llext_add_domain(struct llext *ext, struct k_mem_domain *domain)
 #endif
 }
 
+int llext_heap_init_harvard(void *instr_mem, size_t instr_bytes, void *data_mem, size_t data_bytes)
+{
+#if !defined(CONFIG_LLEXT_HEAP_DYNAMIC) || !defined(CONFIG_HARVARD)
+	return -ENOSYS;
+#else
+	if (llext_heap_inited) {
+		return -EEXIST;
+	}
+
+	k_heap_init(&llext_instr_heap, instr_mem, instr_bytes);
+	k_heap_init(&llext_data_heap, data_mem, data_bytes);
+
+	llext_heap_inited = true;
+	return 0;
+#endif
+}
+
 int llext_heap_init(void *mem, size_t bytes)
 {
-#ifdef CONFIG_LLEXT_HEAP_DYNAMIC
+#if !defined(CONFIG_LLEXT_HEAP_DYNAMIC) || defined(CONFIG_HARVARD)
+	return -ENOSYS;
+#else
 	if (llext_heap_inited) {
 		return -EEXIST;
 	}
+
 	k_heap_init(&llext_heap, mem, bytes);
+
 	llext_heap_inited = true;
 	return 0;
-#else
-	return -ENOSYS;
 #endif
 }
 

tests/subsys/llext/src/test_llext.c

@@ -659,17 +659,33 @@ ZTEST(llext, test_ext_syscall_fail)
 }
 
 #ifdef CONFIG_LLEXT_HEAP_DYNAMIC
+#ifdef CONFIG_HARVARD
+#define TEST_LLEXT_INSTR_HEAP_DYNAMIC_SIZE KB(16)
+static uint8_t llext_instr_heap_data[TEST_LLEXT_INSTR_HEAP_DYNAMIC_SIZE] Z_GENERIC_SECTION(.rodata);
+#define TEST_LLEXT_DATA_HEAP_DYNAMIC_SIZE KB(48)
+static uint8_t llext_data_heap_data[TEST_LLEXT_DATA_HEAP_DYNAMIC_SIZE];
+#else
 #define TEST_LLEXT_HEAP_DYNAMIC_SIZE KB(64)
 static uint8_t llext_heap_data[TEST_LLEXT_HEAP_DYNAMIC_SIZE];
 #endif
+#endif
 
 static void *ztest_suite_setup(void)
 {
 #ifdef CONFIG_LLEXT_HEAP_DYNAMIC
+#ifdef CONFIG_HARVARD
+	zassert_ok(llext_heap_init_harvard(llext_instr_heap_data, sizeof(llext_instr_heap_data),
+					   llext_data_heap_data, sizeof(llext_data_heap_data)));
+	LOG_INF("Allocated LLEXT dynamic instruction heap of size %uKB\n",
+		(unsigned int)(sizeof(llext_instr_heap_data) / KB(1)));
+	LOG_INF("Allocated LLEXT dynamic data heap of size %uKB\n",
+		(unsigned int)(sizeof(llext_data_heap_data) / KB(1)));
+#else
 	/* Test runtime allocation of the LLEXT loader heap */
 	zassert_ok(llext_heap_init(llext_heap_data, sizeof(llext_heap_data)));
 	LOG_INF("Allocated LLEXT dynamic heap of size %uKB\n",
 			(unsigned int)(sizeof(llext_heap_data)/KB(1)));
+#endif
 #endif
 	return NULL;
 }

tests/subsys/llext/testcase.yaml

@@ -154,7 +154,9 @@ tests:
 
   # Test dynamic heap allocation
   llext.dynamic_heap:
-    arch_allow: arm
+    arch_allow:
+      - arm
+      - arc
     filter: not CONFIG_MPU and not CONFIG_MMU
     extra_conf_files: ['no_mem_protection.conf']
     extra_configs: