v4.19.13 snapshot.
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
new file mode 100644
index 0000000..1984421
--- /dev/null
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -0,0 +1,190 @@
+/*
+ * Based on arch/arm/include/asm/cacheflush.h
+ *
+ * Copyright (C) 1999-2002 Russell King.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_CACHEFLUSH_H
+#define __ASM_CACHEFLUSH_H
+
+#include <linux/kgdb.h>
+#include <linux/mm.h>
+
+/*
+ * This flag is used to indicate that the page pointed to by a pte is clean
+ * and does not require cleaning before returning it to the user.
+ */
+#define PG_dcache_clean PG_arch_1
+
+/*
+ * MM Cache Management
+ * ===================
+ *
+ * The arch/arm64/mm/cache.S implements these methods.
+ *
+ * Start addresses are inclusive and end addresses are exclusive; start
+ * addresses should be rounded down, end addresses up.
+ *
+ * See Documentation/core-api/cachetlb.rst for more information. Please note that
+ * the implementation assumes non-aliasing VIPT D-cache and (aliasing)
+ * VIPT I-cache.
+ *
+ * flush_cache_mm(mm)
+ *
+ * Clean and invalidate all user space cache entries
+ * before a change of page tables.
+ *
+ * flush_icache_range(start, end)
+ *
+ * Ensure coherency between the I-cache and the D-cache in the
+ * region described by start, end.
+ * - start - virtual start address
+ * - end - virtual end address
+ *
+ * invalidate_icache_range(start, end)
+ *
+ * Invalidate the I-cache in the region described by start, end.
+ * - start - virtual start address
+ * - end - virtual end address
+ *
+ * __flush_cache_user_range(start, end)
+ *
+ * Ensure coherency between the I-cache and the D-cache in the
+ * region described by start, end.
+ * - start - virtual start address
+ * - end - virtual end address
+ *
+ * __flush_dcache_area(kaddr, size)
+ *
+ * Ensure that the data held in page is written back.
+ * - kaddr - page address
+ * - size - region size
+ */
+extern void __flush_icache_range(unsigned long start, unsigned long end);
+extern int invalidate_icache_range(unsigned long start, unsigned long end);
+extern void __flush_dcache_area(void *addr, size_t len);
+extern void __inval_dcache_area(void *addr, size_t len);
+extern void __clean_dcache_area_poc(void *addr, size_t len);
+extern void __clean_dcache_area_pop(void *addr, size_t len);
+extern void __clean_dcache_area_pou(void *addr, size_t len);
+extern long __flush_cache_user_range(unsigned long start, unsigned long end);
+extern void sync_icache_aliases(void *kaddr, unsigned long len);
+
+static inline void flush_icache_range(unsigned long start, unsigned long end)
+{
+ __flush_icache_range(start, end);
+
+ /*
+ * IPI all online CPUs so that they undergo a context synchronization
+ * event and are forced to refetch the new instructions.
+ */
+#ifdef CONFIG_KGDB
+ /*
+ * KGDB performs cache maintenance with interrupts disabled, so we
+ * will deadlock trying to IPI the secondary CPUs. In theory, we can
+ * set CACHE_FLUSH_IS_SAFE to 0 to avoid this known issue, but that
+ * just means that KGDB will elide the maintenance altogether! As it
+ * turns out, KGDB uses IPIs to round-up the secondary CPUs during
+ * the patching operation, so we don't need extra IPIs here anyway.
+ * In which case, add a KGDB-specific bodge and return early.
+ */
+ if (kgdb_connected && irqs_disabled())
+ return;
+#endif
+ kick_all_cpus_sync();
+}
+
+static inline void flush_cache_mm(struct mm_struct *mm)
+{
+}
+
+static inline void flush_cache_page(struct vm_area_struct *vma,
+ unsigned long user_addr, unsigned long pfn)
+{
+}
+
+static inline void flush_cache_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+}
+
+/*
+ * Cache maintenance functions used by the DMA API. No to be used directly.
+ */
+extern void __dma_map_area(const void *, size_t, int);
+extern void __dma_unmap_area(const void *, size_t, int);
+extern void __dma_flush_area(const void *, size_t);
+
+/*
+ * Copy user data from/to a page which is mapped into a different
+ * processes address space. Really, we want to allow our "user
+ * space" model to handle this.
+ */
+extern void copy_to_user_page(struct vm_area_struct *, struct page *,
+ unsigned long, void *, const void *, unsigned long);
+#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
+ do { \
+ memcpy(dst, src, len); \
+ } while (0)
+
+#define flush_cache_dup_mm(mm) flush_cache_mm(mm)
+
+/*
+ * flush_dcache_page is used when the kernel has written to the page
+ * cache page at virtual address page->virtual.
+ *
+ * If this page isn't mapped (ie, page_mapping == NULL), or it might
+ * have userspace mappings, then we _must_ always clean + invalidate
+ * the dcache entries associated with the kernel mapping.
+ *
+ * Otherwise we can defer the operation, and clean the cache when we are
+ * about to change to user space. This is the same method as used on SPARC64.
+ * See update_mmu_cache for the user space part.
+ */
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
+extern void flush_dcache_page(struct page *);
+
+static inline void __flush_icache_all(void)
+{
+ if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC))
+ return;
+
+ asm("ic ialluis");
+ dsb(ish);
+}
+
+#define flush_dcache_mmap_lock(mapping) do { } while (0)
+#define flush_dcache_mmap_unlock(mapping) do { } while (0)
+
+/*
+ * We don't appear to need to do anything here. In fact, if we did, we'd
+ * duplicate cache flushing elsewhere performed by flush_dcache_page().
+ */
+#define flush_icache_page(vma,page) do { } while (0)
+
+/*
+ * Not required on AArch64 (PIPT or VIPT non-aliasing D-cache).
+ */
+static inline void flush_cache_vmap(unsigned long start, unsigned long end)
+{
+}
+
+static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
+{
+}
+
+int set_memory_valid(unsigned long addr, int numpages, int enable);
+
+#endif