tests/boards/intel_adsp: Add cache related tests

Tests that exercise z_xtensa_cache_[flush|inv|flush_inv]_all()
functions.

These tests are at board level because what is mapped into memory is
SoC/board dependent - no one wants side effects due writing to some
inappropriate address.

Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>

tests/boards/intel_adsp/cache/CMakeLists.txt

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(adsp_cache)
+
+target_sources(app PRIVATE src/main.c)

tests/boards/intel_adsp/cache/prj.conf

@@ -0,0 +1,2 @@
+CONFIG_ZTEST=y
+CONFIG_ZTEST_NEW_API=y

tests/boards/intel_adsp/cache/src/main.c

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2022 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+#include <adsp_memory.h>
+
+ZTEST(adsp_cache, test_adsp_cache_flush_inv_all)
+{
+	uint32_t *cached, *uncached;
+
+	cached = (uint32_t *)LP_SRAM_BASE;
+	uncached = arch_xtensa_uncached_ptr(cached);
+
+	*cached = 42;
+	*uncached = 40;
+
+	/* Just some sanity checks */
+	zassert_equal(*cached, 42, NULL);
+	zassert_equal(*uncached, 40, NULL);
+
+	z_xtensa_cache_flush_inv_all();
+
+	/* After z_xtensa_cache_flush_inv_all(), uncached should be updated */
+	zassert_equal(*cached, 42, NULL);
+	zassert_equal(*uncached, 42, NULL);
+
+	/* Flush and invalidate again, this time to check the invalidate part */
+	z_xtensa_cache_flush_inv_all();
+	*uncached = 80;
+
+	/* As cache is invalid, cached should be updated with uncached new value */
+	zassert_equal(*cached, 80, NULL);
+	zassert_equal(*uncached, 80, NULL);
+
+	*cached = 82;
+
+	/* Only cached should have changed */
+	zassert_equal(*cached, 82, NULL);
+	zassert_equal(*uncached, 80, NULL);
+
+	z_xtensa_cache_flush_all();
+
+	/* After z_xtensa_cache_flush_all(), uncached should be updated */
+	zassert_equal(*cached, 82, NULL);
+	zassert_equal(*uncached, 82, NULL);
+
+	*uncached = 100;
+
+	/* As cache is not invalid, only uncached should be updated */
+	zassert_equal(*cached, 82, NULL);
+	zassert_equal(*uncached, 100, NULL);
+
+	z_xtensa_cache_inv_all();
+
+	/* Now, cached should be updated */
+	zassert_equal(*cached, 100, NULL);
+	zassert_equal(*uncached, 100, NULL);
+}
+
+ZTEST_SUITE(adsp_cache, NULL, NULL, NULL, NULL, NULL);

tests/boards/intel_adsp/cache/testcase.yaml

@@ -0,0 +1,5 @@
+common:
+  tags: boards
+tests:
+  boards.intel_adsp.cache:
+    platform_allow: intel_adsp_cavs15 intel_adsp_cavs18 intel_adsp_cavs25