tree d9cc9c4bb88ec09a7b03fe173e8e9ff91d1b9d0f
parent 0baf54d0056979d6344b872a5b20acb6a5fd3cf8
author Philippe Mathieu-Daudé <philmd@linaro.org> 1685994774 +0200
committer Philippe Mathieu-Daudé <philmd@linaro.org> 1686648538 +0200

util/cacheflush: Avoid possible redundant dcache flush on Darwin

<libkern/OSCacheControl.h> describes sys_icache_invalidate() as
"equivalent to sys_cache_control(kCacheFunctionPrepareForExecution)",
having kCacheFunctionPrepareForExecution defined as:

  /* Prepare memory for execution.  This should be called
   * after writing machine instructions to memory, before
   * executing them.  It syncs the dcache and icache. [...]
   */

Since the dcache is also sync'd, we can avoid the sys_dcache_flush()
call when both rx/rw pointers are equal.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230605195911.96033-1-philmd@linaro.org>