efi_loader: avoid duplicate weak invalidate_icache_all()

If multiple weak implementations of a weak function exist, it is unclear
which one the linker should chose. cmd/cache.c already defines a weak
invalidate_icache_all().

We don't need a call to invalidate_icache_all() on x86.
ARM, RISC-V, and Sandbox provide an implementation.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
index 6042436..45dc5b6 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -173,11 +173,6 @@
 	return EFI_SUCCESS;
 }
 
-void __weak invalidate_icache_all(void)
-{
-	/* If the system doesn't support icache_all flush, cross our fingers */
-}
-
 /**
  * efi_set_code_and_data_type() - determine the memory types to be used for code
  *				  and data.
@@ -986,7 +981,13 @@
 	/* Flush cache */
 	flush_cache((ulong)efi_reloc,
 		    ALIGN(virt_size, EFI_CACHELINE_SIZE));
-	invalidate_icache_all();
+
+	/*
+	 * If on x86 a write affects a prefetched instruction,
+	 * the prefetch queue is invalidated.
+	 */
+	if (!CONFIG_IS_ENABLED(X86))
+		invalidate_icache_all();
 
 	/* Populate the loaded image interface bits */
 	loaded_image_info->image_base = efi_reloc;
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 011bcd0..05369c4 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -783,7 +783,12 @@
 	lastoff = offset;
 #endif
 
-        invalidate_icache_all();
+	/*
+	 * If on x86 a write affects a prefetched instruction,
+	 * the prefetch queue is invalidated.
+	 */
+	if (!CONFIG_IS_ENABLED(X86))
+		invalidate_icache_all();
 }
 
 /**