v4.19.13 snapshot.
diff --git a/arch/powerpc/kernel/vdso64/cacheflush.S b/arch/powerpc/kernel/vdso64/cacheflush.S
new file mode 100644
index 0000000..69c5af2
--- /dev/null
+++ b/arch/powerpc/kernel/vdso64/cacheflush.S
@@ -0,0 +1,84 @@
+/*
+ * vDSO provided cache flush routines
+ *
+ * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org),
+ * IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+
+ .text
+
+/*
+ * Default "generic" version of __kernel_sync_dicache.
+ *
+ * void __kernel_sync_dicache(unsigned long start, unsigned long end)
+ *
+ * Flushes the data cache & invalidate the instruction cache for the
+ * provided range [start, end[
+ */
+V_FUNCTION_BEGIN(__kernel_sync_dicache)
+ .cfi_startproc
+ mflr r12
+ .cfi_register lr,r12
+ mr r11,r3
+ bl V_LOCAL_FUNC(__get_datapage)
+ mtlr r12
+ mr r10,r3
+
+ lwz r7,CFG_DCACHE_BLOCKSZ(r10)
+ addi r5,r7,-1
+ andc r6,r11,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5 /* ensure we get enough */
+ lwz r9,CFG_DCACHE_LOGBLOCKSZ(r10)
+ srw. r8,r8,r9 /* compute line count */
+ crclr cr0*4+so
+ beqlr /* nothing to do? */
+ mtctr r8
+1: dcbst 0,r6
+ add r6,r6,r7
+ bdnz 1b
+ sync
+
+/* Now invalidate the instruction cache */
+
+ lwz r7,CFG_ICACHE_BLOCKSZ(r10)
+ addi r5,r7,-1
+ andc r6,r11,r5 /* round low to line bdy */
+ subf r8,r6,r4 /* compute length */
+ add r8,r8,r5
+ lwz r9,CFG_ICACHE_LOGBLOCKSZ(r10)
+ srw. r8,r8,r9 /* compute line count */
+ crclr cr0*4+so
+ beqlr /* nothing to do? */
+ mtctr r8
+2: icbi 0,r6
+ add r6,r6,r7
+ bdnz 2b
+ isync
+ li r3,0
+ blr
+ .cfi_endproc
+V_FUNCTION_END(__kernel_sync_dicache)
+
+
+/*
+ * POWER5 version of __kernel_sync_dicache
+ */
+V_FUNCTION_BEGIN(__kernel_sync_dicache_p5)
+ .cfi_startproc
+ crclr cr0*4+so
+ sync
+ isync
+ li r3,0
+ blr
+ .cfi_endproc
+V_FUNCTION_END(__kernel_sync_dicache_p5)