--- zzzz-none-000/linux-3.10.107/arch/arm64/mm/flush.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/arm64/mm/flush.c	2021-02-04 17:41:59.000000000 +0000
@@ -60,19 +60,10 @@
 		       unsigned long uaddr, void *dst, const void *src,
 		       unsigned long len)
 {
-#ifdef CONFIG_SMP
 	preempt_disable();
-#endif
 	memcpy(dst, src, len);
 	flush_ptrace_access(vma, page, uaddr, dst, len);
-#ifdef CONFIG_SMP
 	preempt_enable();
-#endif
-}
-
-void __flush_dcache_page(struct page *page)
-{
-	__flush_dcache_area(page_address(page), PAGE_SIZE);
 }
 
 void __sync_icache_dcache(pte_t pte, unsigned long addr)
@@ -84,7 +75,8 @@
 		return;
 
 	if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
-		__flush_dcache_page(page);
+		__flush_dcache_area(page_address(page),
+				PAGE_SIZE << compound_order(page));
 		__flush_icache_all();
 	} else if (icache_is_aivivt()) {
 		__flush_icache_all();
@@ -106,5 +98,38 @@
 /*
  * Additional functions defined in assembly.
  */
-EXPORT_SYMBOL(flush_cache_all);
 EXPORT_SYMBOL(flush_icache_range);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
+			  pmd_t *pmdp)
+{
+	pmd_t pmd = pmd_mksplitting(*pmdp);
+
+	VM_BUG_ON(address & ~PMD_MASK);
+	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+
+	/* dummy IPI to serialise against fast_gup */
+	kick_all_cpus_sync();
+}
+#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+void dmac_flush_range(const void *start, const void *end)
+{
+	__dma_flush_range(start, end);
+}
+EXPORT_SYMBOL(dmac_flush_range);
+
+void dmac_inv_range(const void *start, const void *end)
+{
+	__dma_inv_range(start, end);
+}
+EXPORT_SYMBOL(dmac_inv_range);
+
+void dmac_clean_range(const void *start, const void *end)
+{
+	__dma_clean_range(start, end);
+}
+EXPORT_SYMBOL(dmac_clean_range);