rtems+bsps/cache: Define cache manager operations for code synchronization and maximal alignment.

There is need for unambiguous named and defined cache function
which should be called when code is updated, loaded
or is self-modifying.

There should be function to obtain maximal cache line length
as well. This function can and should be used for allocations
which can be used for data and or code and ensures that
there are no partial cache lines overlaps on start and
end of allocated region.

Updates #2782

1 files changed, 42 insertions, 0 deletions

diff --git a/c/src/lib/libcpu/shared/src/cache_manager.c b/c/src/lib/libcpu/shared/src/cache_manager.c
index 202ea8e1ba..00d2476fa9 100644
--- a/c/src/lib/libcpu/shared/src/cache_manager.c
+++ b/c/src/lib/libcpu/shared/src/cache_manager.c
@@ -469,3 +469,45 @@ rtems_cache_disable_instruction( void )
   _CPU_cache_disable_instruction();
 #endif
 }
+
+/* Returns the maximal cache line size of all cache kinds in bytes. */
+size_t rtems_cache_get_maximal_line_size( void )
+{
+#if defined(CPU_MAXIMAL_CACHE_ALIGNMENT)
+  return CPU_MAXIMAL_CACHE_ALIGNMENT;
+#endif
+  size_t max_line_size = 0;
+#if defined(CPU_DATA_CACHE_ALIGNMENT)
+  {
+    size_t data_line_size = CPU_DATA_CACHE_ALIGNMENT;
+    if ( max_line_size < data_line_size )
+      max_line_size = data_line_size;
+  }
+#endif
+#if defined(CPU_INSTRUCTION_CACHE_ALIGNMENT)
+  {
+    size_t instruction_line_size = CPU_INSTRUCTION_CACHE_ALIGNMENT;
+    if ( max_line_size < instruction_line_size )
+      max_line_size = instruction_line_size;
+  }
+#endif
+  return max_line_size;
+}
+
+/*
+ * Purpose is to synchronize caches after code has been loaded
+ * or self modified. Actual implementation is simple only
+ * but it can and should be repaced by optimized version
+ * which does not need flush and invalidate all cache levels
+ * when code is changed.
+ */
+void
+rtems_cache_instruction_sync_after_code_change( const void * code_addr, size_t n_bytes )
+{
+#if defined(CPU_CACHE_SUPPORT_PROVIDES_INSTRUCTION_SYNC_FUNCTION)
+  _CPU_cache_instruction_sync_after_code_change( code_addr, n_bytes );
+#else
+  rtems_cache_flush_multiple_data_lines( code_addr, n_bytes );
+  rtems_cache_invalidate_multiple_instruction_lines( code_addr, n_bytes );
+#endif
+}