diff --git a/Documentation/arm64/legacy_instructions.txt b/Documentation/arm64/legacy_instructions.txt
index 5ab5861..a3b3da2 100644
--- a/Documentation/arm64/legacy_instructions.txt
+++ b/Documentation/arm64/legacy_instructions.txt
@@ -38,3 +38,8 @@ Supported legacy instructions
 Node: /proc/sys/abi/swp
 Status: Obsolete
 Default: Undef (0)
+
+* CP15 Barriers
+Node: /proc/sys/abi/cp15_barrier
+Status: Deprecated
+Default: Emulate (1)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2d59bfc..250ca25 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -199,6 +199,21 @@ config SWP_EMULATION
 
 	  If unsure, say Y
 
+config CP15_BARRIER_EMULATION
+	bool "Emulate CP15 Barrier instructions"
+	help
+	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
+	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
+	  strongly recommended to use the ISB, DSB, and DMB
+	  instructions instead.
+
+	  Say Y here to enable software emulation of these
+	  instructions for AArch32 userspace code. When this option is
+	  enabled, CP15 barrier usage is traced which can help
+	  identify software that needs updating.
+
+	  If unsure, say Y
+
 endif
 
 endmenu
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 3ecc57c..e2ff32a 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -362,6 +362,8 @@ bool aarch32_insn_is_wide(u32 insn);
 #define A32_RT2_OFFSET	 0
 
 u32 aarch32_insn_extract_reg_num(u32 insn, int offset);
+u32 aarch32_insn_mcr_extract_opc2(u32 insn);
+u32 aarch32_insn_mcr_extract_crm(u32 insn);
 #endif /* __ASSEMBLY__ */
 
 #endif	/* __ASM_INSN_H */
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index bedf52c..248b222 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -6,6 +6,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/cpu.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
@@ -236,6 +237,133 @@ static struct insn_emulation_ops swp_ops = {
 	.set_hw_mode = NULL,
 };
 
+static int cp15barrier_handler(struct pt_regs *regs, u32 instr)
+{
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
+
+	switch (arm_check_condition(instr, regs->pstate)) {
+	case ARM_OPCODE_CONDTEST_PASS:
+		break;
+	case ARM_OPCODE_CONDTEST_FAIL:
+		/* Condition failed - return to next instruction */
+		goto ret;
+	case ARM_OPCODE_CONDTEST_UNCOND:
+		/* If unconditional encoding - not a barrier instruction */
+		return -EFAULT;
+	default:
+		return -EINVAL;
+	}
+
+	switch (aarch32_insn_mcr_extract_crm(instr)) {
+	case 10:
+		/*
+		 * dmb - mcr p15, 0, Rt, c7, c10, 5
+		 * dsb - mcr p15, 0, Rt, c7, c10, 4
+		 */
+		if (aarch32_insn_mcr_extract_opc2(instr) == 5)
+			dmb(sy);
+		else
+			dsb(sy);
+		break;
+	case 5:
+		/*
+		 * isb - mcr p15, 0, Rt, c7, c5, 4
+		 *
+		 * Taking an exception or returning from one acts as an
+		 * instruction barrier. So no explicit barrier needed here.
+		 */
+		break;
+	}
+
+ret:
+	pr_warn_ratelimited("\"%s\" (%ld) uses deprecated CP15 Barrier instruction at 0x%llx\n",
+			current->comm, (unsigned long)current->pid, regs->pc);
+
+	regs->pc += 4;
+	return 0;
+}
+
+#define SCTLR_EL1_CP15BEN (1 << 5)
+
+static inline void config_sctlr_el1(u32 clear, u32 set)
+{
+	u32 val;
+
+	asm volatile("mrs %0, sctlr_el1" : "=r" (val));
+	val &= ~clear;
+	val |= set;
+	asm volatile("msr sctlr_el1, %0" : : "r" (val));
+}
+
+static void enable_cp15_ben(void *info)
+{
+	config_sctlr_el1(0, SCTLR_EL1_CP15BEN);
+}
+
+static void disable_cp15_ben(void *info)
+{
+	config_sctlr_el1(SCTLR_EL1_CP15BEN, 0);
+}
+
+static int cpu_hotplug_notify(struct notifier_block *b,
+			      unsigned long action, void *hcpu)
+{
+	switch (action) {
+	case CPU_STARTING:
+	case CPU_STARTING_FROZEN:
+		enable_cp15_ben(NULL);
+		return NOTIFY_DONE;
+	case CPU_DYING:
+	case CPU_DYING_FROZEN:
+		disable_cp15_ben(NULL);
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpu_hotplug_notifier = {
+	.notifier_call = cpu_hotplug_notify,
+};
+
+static int cp15_barrier_set_hw_mode(bool enable)
+{
+	if (enable) {
+		register_cpu_notifier(&cpu_hotplug_notifier);
+		on_each_cpu(enable_cp15_ben, NULL, true);
+	} else {
+		unregister_cpu_notifier(&cpu_hotplug_notifier);
+		on_each_cpu(disable_cp15_ben, NULL, true);
+	}
+
+	return true;
+}
+
+static struct undef_hook cp15_barrier_hooks[] = {
+	{
+		.instr_mask	= 0x0fff0fdf,
+		.instr_val	= 0x0e070f9a,
+		.pstate_mask	= COMPAT_PSR_MODE_MASK,
+		.pstate_val	= COMPAT_PSR_MODE_USR,
+		.fn		= cp15barrier_handler,
+	},
+	{
+		.instr_mask	= 0x0fff0fff,
+		.instr_val	= 0x0e070f95,
+		.pstate_mask	= COMPAT_PSR_MODE_MASK,
+		.pstate_val	= COMPAT_PSR_MODE_USR,
+		.fn		= cp15barrier_handler,
+	},
+	{ }
+};
+
+static struct insn_emulation_ops cp15_barrier_ops = {
+	.name = "cp15_barrier",
+	.status = INSN_DEPRECATED,
+	.hooks = cp15_barrier_hooks,
+	.set_hw_mode = cp15_barrier_set_hw_mode,
+};
+
 static LIST_HEAD(insn_emulation);
 static int nr_insn_emulated;
 static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
@@ -411,6 +539,9 @@ static int __init armv8_deprecated_init(void)
 	if (IS_ENABLED(CONFIG_SWP_EMULATION))
 		register_insn_emulation(&swp_ops);
 
+	if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
+		register_insn_emulation(&cp15_barrier_ops);
+
 	register_insn_emulation_sysctl(ctl_abi);
 
 	return 0;
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 63122dc..819e409 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -972,3 +972,16 @@ u32 aarch32_insn_extract_reg_num(u32 insn, int offset)
 {
 	return (insn & (0xf << offset)) >> offset;
 }
+
+#define OPC2_MASK	0x7
+#define OPC2_OFFSET	5
+u32 aarch32_insn_mcr_extract_opc2(u32 insn)
+{
+	return (insn & (OPC2_MASK << OPC2_OFFSET)) >> OPC2_OFFSET;
+}
+
+#define CRM_MASK	0xf
+u32 aarch32_insn_mcr_extract_crm(u32 insn)
+{
+	return insn & CRM_MASK;
+}
