heap: add check for usage of flash content from iram

this commits:
- adds build-time test to check that no call to flash regions are done from IRAM functions

- resolves problems related to IRAM function using content in flash memory

- update heap_caps_alloc_failed to use a default function name in DRAM
  when necessary instead of creating a function name variable in DRAM for
  each call of heap_caps_alloc_failed. This allows to save some extra bytes
  in RAM.

components/heap/CMakeLists.txt

@@ -22,7 +22,7 @@ endif()
 idf_component_register(SRCS "${srcs}"
                     INCLUDE_DIRS include
                     LDFRAGMENTS linker.lf
-                    PRIV_REQUIRES soc)
+                    PRIV_REQUIRES soc spi_flash)
 
 if(CONFIG_HEAP_TRACING)
     set(WRAP_FUNCTIONS

components/heap/heap_caps.c

@@ -22,7 +22,7 @@
 #include "esp_log.h"
 #include "heap_private.h"
 #include "esp_system.h"
-
+#include "esp_private/cache_utils.h"
 
 // forward declaration
 IRAM_ATTR static void *heap_caps_realloc_base( void *ptr, size_t size, uint32_t caps);
@@ -61,11 +61,17 @@ IRAM_ATTR static void *dram_alloc_to_iram_addr(void *addr, size_t len)
 }
 
 
-static void heap_caps_alloc_failed(size_t requested_size, uint32_t caps, const char *function_name)
+IRAM_ATTR static void heap_caps_alloc_failed(size_t requested_size, uint32_t caps, const char *function_name)
 {
+    static const DRAM_ATTR char *default_func_name = "<function_name>";
     if (alloc_failed_callback) {
+        if (!spi_flash_cache_enabled() && !esp_ptr_internal(function_name)) {
+            alloc_failed_callback(requested_size, caps, default_func_name);
+        }
+        else {
             alloc_failed_callback(requested_size, caps, function_name);
         }
+    }
 
     #ifdef CONFIG_HEAP_ABORT_WHEN_ALLOCATION_FAILS
     esp_system_abort("Memory allocation failed");

components/heap/heap_private.h

@@ -51,7 +51,7 @@ extern SLIST_HEAD(registered_heap_ll, heap_t_) registered_heaps;
 bool heap_caps_match(const heap_t *heap, uint32_t caps);
 
 /* return all possible capabilities (across all priorities) for a given heap */
-inline static uint32_t get_all_caps(const heap_t *heap)
+inline static __attribute__((always_inline)) uint32_t get_all_caps(const heap_t *heap)
 {
     if (heap->heap == NULL) {
         return 0;

components/heap/test/CMakeLists.txt

@@ -1,3 +1,17 @@
 idf_component_register(SRC_DIRS "."
                     PRIV_INCLUDE_DIRS "."
                     PRIV_REQUIRES cmock test_utils heap)
+
+if(CONFIG_COMPILER_DUMP_RTL_FILES)
+    idf_build_get_property(elf_file_name EXECUTABLE GENERATOR_EXPRESSION)
+    add_custom_target(check_test_app_sections ALL
+                      COMMAND ${PYTHON} $ENV{IDF_PATH}/tools/ci/check_callgraph.py
+                      --rtl-dir ${CMAKE_BINARY_DIR}/esp-idf/heap/
+                      --elf-file ${CMAKE_BINARY_DIR}/${elf_file_name}
+                      find-refs
+                      --from-sections=.iram0.text
+                      --to-sections=.flash.text,.flash.rodata
+                      --exit-code
+                      DEPENDS ${elf_file_name}
+                      )
+endif()

tools/unit-test-app/sdkconfig.defaults

@@ -26,3 +26,4 @@ CONFIG_SPIRAM_BANKSWITCH_ENABLE=n
 CONFIG_FATFS_ALLOC_PREFER_EXTRAM=y
 CONFIG_UNITY_ENABLE_BACKTRACE_ON_FAIL=y
 CONFIG_ESP_NETIF_TCPIP_ADAPTER_COMPATIBLE_LAYER=n
+CONFIG_COMPILER_DUMP_RTL_FILES=y