v4.19.13 snapshot.
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
new file mode 100644
index 0000000..ec1e6d6
--- /dev/null
+++ b/arch/arm64/include/asm/fixmap.h
@@ -0,0 +1,108 @@
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1998 Ingo Molnar
+ * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
+ *
+ * Adapted from arch/x86 version.
+ *
+ */
+
+#ifndef _ASM_ARM64_FIXMAP_H
+#define _ASM_ARM64_FIXMAP_H
+
+#ifndef __ASSEMBLY__
+#include <linux/kernel.h>
+#include <linux/sizes.h>
+#include <asm/boot.h>
+#include <asm/page.h>
+#include <asm/pgtable-prot.h>
+
+/*
+ * Here we define all the compile-time 'special' virtual
+ * addresses. The point is to have a constant address at
+ * compile time, but to set the physical address only
+ * in the boot process.
+ *
+ * These 'compile-time allocated' memory buffers are
+ * page-sized. Use set_fixmap(idx,phys) to associate
+ * physical memory with fixmap indices.
+ *
+ */
+enum fixed_addresses {
+	FIX_HOLE,
+
+	/*
+	 * Reserve a virtual window for the FDT that is 2 MB larger than the
+	 * maximum supported size, and put it at the top of the fixmap region.
+	 * The additional space ensures that any FDT that does not exceed
+	 * MAX_FDT_SIZE can be mapped regardless of whether it crosses any
+	 * 2 MB alignment boundaries.
+	 *
+	 * Keep this at the top so it remains 2 MB aligned.
+	 */
+#define FIX_FDT_SIZE		(MAX_FDT_SIZE + SZ_2M)
+	FIX_FDT_END,
+	FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
+
+	FIX_EARLYCON_MEM_BASE,
+	FIX_TEXT_POKE0,
+
+#ifdef CONFIG_ACPI_APEI_GHES
+	/* Used for GHES mapping from assorted contexts */
+	FIX_APEI_GHES_IRQ,
+	FIX_APEI_GHES_NMI,
+#endif /* CONFIG_ACPI_APEI_GHES */
+
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+	FIX_ENTRY_TRAMP_DATA,
+	FIX_ENTRY_TRAMP_TEXT,
+#define TRAMP_VALIAS		(__fix_to_virt(FIX_ENTRY_TRAMP_TEXT))
+#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
+	__end_of_permanent_fixed_addresses,
+
+	/*
+	 * Temporary boot-time mappings, used by early_ioremap(),
+	 * before ioremap() is functional.
+	 */
+#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
+#define FIX_BTMAPS_SLOTS	7
+#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
+
+	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
+
+	/*
+	 * Used for kernel page table creation, so unmapped memory may be used
+	 * for tables.
+	 */
+	FIX_PTE,
+	FIX_PMD,
+	FIX_PUD,
+	FIX_PGD,
+
+	__end_of_fixed_addresses
+};
+
+#define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
+
+#define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
+
+void __init early_fixmap_init(void);
+
+#define __early_set_fixmap __set_fixmap
+
+#define __late_set_fixmap __set_fixmap
+#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
+
+extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
+
+#include <asm-generic/fixmap.h>
+
+#endif /* !__ASSEMBLY__ */
+#endif /* _ASM_ARM64_FIXMAP_H */