fast-get: Fix shared data usage by multiple callers

fast_get() for the same data can be called by multiple clients from
the same or other cores. Since sram_ptr points to cached memory, writeback
is needed after memcpy() to also copy data to uncached memory. When
fast_get() is called a second time for the same data, invalidate() is used
to bring shared data into another core's cache.

This fixes tests which use two SRC modules.

Signed-off-by: Serhiy Katsyuba <serhiy.katsyuba@intel.com>

Author: serhiy-katsyuba-intel

zephyr/lib/fast-get.c

@@ -117,12 +117,13 @@ const void *z_impl_fast_get(struct k_heap *heap, const void *dram_ptr, size_t si
 		goto out;
 	}
 
-	ret = sof_heap_alloc(heap, SOF_MEM_FLAG_USER, size, 0);
+	ret = sof_heap_alloc(heap, SOF_MEM_FLAG_USER, size, PLATFORM_DCACHE_ALIGN);
 	if (!ret)
 		goto out;
 	entry->size = size;
 	entry->sram_ptr = ret;
 	memcpy_s(entry->sram_ptr, entry->size, dram_ptr, size);
+	dcache_writeback_region((__sparse_force void __sparse_cache *)entry->sram_ptr, size);
 	entry->dram_ptr = dram_ptr;
 	entry->refcount = 1;
 out: