v4.19.13 snapshot.
diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h
new file mode 100644
index 0000000..69772e7
--- /dev/null
+++ b/arch/arm/include/asm/barrier.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_BARRIER_H
+#define __ASM_BARRIER_H
+
+#ifndef __ASSEMBLY__
+
+#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
+
+#if __LINUX_ARM_ARCH__ >= 7 || \
+ (__LINUX_ARM_ARCH__ == 6 && defined(CONFIG_CPU_32v6K))
+#define sev() __asm__ __volatile__ ("sev" : : : "memory")
+#define wfe() __asm__ __volatile__ ("wfe" : : : "memory")
+#define wfi() __asm__ __volatile__ ("wfi" : : : "memory")
+#endif
+
+#if __LINUX_ARM_ARCH__ >= 7
+#define isb(option) __asm__ __volatile__ ("isb " #option : : : "memory")
+#define dsb(option) __asm__ __volatile__ ("dsb " #option : : : "memory")
+#define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory")
+#ifdef CONFIG_THUMB2_KERNEL
+#define CSDB ".inst.w 0xf3af8014"
+#else
+#define CSDB ".inst 0xe320f014"
+#endif
+#define csdb() __asm__ __volatile__(CSDB : : : "memory")
+#elif defined(CONFIG_CPU_XSC3) || __LINUX_ARM_ARCH__ == 6
+#define isb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
+ : : "r" (0) : "memory")
+#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
+ : : "r" (0) : "memory")
+#define dmb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
+ : : "r" (0) : "memory")
+#elif defined(CONFIG_CPU_FA526)
+#define isb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
+ : : "r" (0) : "memory")
+#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
+ : : "r" (0) : "memory")
+#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
+#else
+#define isb(x) __asm__ __volatile__ ("" : : : "memory")
+#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
+ : : "r" (0) : "memory")
+#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
+#endif
+
+#ifndef CSDB
+#define CSDB
+#endif
+#ifndef csdb
+#define csdb()
+#endif
+
+#ifdef CONFIG_ARM_HEAVY_MB
+extern void (*soc_mb)(void);
+extern void arm_heavy_mb(void);
+#define __arm_heavy_mb(x...) do { dsb(x); arm_heavy_mb(); } while (0)
+#else
+#define __arm_heavy_mb(x...) dsb(x)
+#endif
+
+#if defined(CONFIG_ARM_DMA_MEM_BUFFERABLE) || defined(CONFIG_SMP)
+#define mb() __arm_heavy_mb()
+#define rmb() dsb()
+#define wmb() __arm_heavy_mb(st)
+#define dma_rmb() dmb(osh)
+#define dma_wmb() dmb(oshst)
+#else
+#define mb() barrier()
+#define rmb() barrier()
+#define wmb() barrier()
+#define dma_rmb() barrier()
+#define dma_wmb() barrier()
+#endif
+
+#define __smp_mb() dmb(ish)
+#define __smp_rmb() __smp_mb()
+#define __smp_wmb() dmb(ishst)
+
+#ifdef CONFIG_CPU_SPECTRE
+static inline unsigned long array_index_mask_nospec(unsigned long idx,
+ unsigned long sz)
+{
+ unsigned long mask;
+
+ asm volatile(
+ "cmp %1, %2\n"
+ " sbc %0, %1, %1\n"
+ CSDB
+ : "=r" (mask)
+ : "r" (idx), "Ir" (sz)
+ : "cc");
+
+ return mask;
+}
+#define array_index_mask_nospec array_index_mask_nospec
+#endif
+
+#include <asm-generic/barrier.h>
+
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_BARRIER_H */