--- zzzz-none-000/linux-4.9.276/arch/mips/mm/cache.c	2021-07-20 14:21:16.000000000 +0000
+++ falcon-5530-750/linux-4.9.276/arch/mips/mm/cache.c	2023-04-05 08:19:00.000000000 +0000
@@ -63,6 +63,8 @@
 void (*_dma_cache_inv)(unsigned long start, unsigned long size);
 
 EXPORT_SYMBOL(_dma_cache_wback_inv);
+EXPORT_SYMBOL(_dma_cache_wback);
+EXPORT_SYMBOL(_dma_cache_inv);
 
 #endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
 
@@ -115,6 +117,13 @@
 {
 	unsigned long addr = (unsigned long) page_address(page);
 
+	if (PageHighMem(page)) {
+		addr = (unsigned long)kmap_atomic(page);
+		flush_data_cache_page(addr);
+		__kunmap_atomic((void *)addr);
+		return;
+	}
+
 	if (pages_do_alias(addr, vmaddr)) {
 		if (page_mapcount(page) && !Page_dcache_dirty(page)) {
 			void *kaddr;