diff --git a/lib/cpus/aarch64/cortex_a57.S b/lib/cpus/aarch64/cortex_a57.S
index 721bb49..07fadd1 100644
--- a/lib/cpus/aarch64/cortex_a57.S
+++ b/lib/cpus/aarch64/cortex_a57.S
@@ -573,8 +573,9 @@
 	ret
 endfunc cortex_a57_cpu_reg_dump
 
-declare_cpu_ops_workaround_cve_2017_5715 cortex_a57, CORTEX_A57_MIDR, \
+declare_cpu_ops_wa cortex_a57, CORTEX_A57_MIDR, \
 	cortex_a57_reset_func, \
 	check_errata_cve_2017_5715, \
+	CPU_NO_EXTRA2_FUNC, \
 	cortex_a57_core_pwr_dwn, \
 	cortex_a57_cluster_pwr_dwn
diff --git a/lib/cpus/aarch64/cortex_a72.S b/lib/cpus/aarch64/cortex_a72.S
index 6ef35cf..bb9381d 100644
--- a/lib/cpus/aarch64/cortex_a72.S
+++ b/lib/cpus/aarch64/cortex_a72.S
@@ -310,8 +310,9 @@
 	ret
 endfunc cortex_a72_cpu_reg_dump
 
-declare_cpu_ops_workaround_cve_2017_5715 cortex_a72, CORTEX_A72_MIDR, \
+declare_cpu_ops_wa cortex_a72, CORTEX_A72_MIDR, \
 	cortex_a72_reset_func, \
 	check_errata_cve_2017_5715, \
+	CPU_NO_EXTRA2_FUNC, \
 	cortex_a72_core_pwr_dwn, \
 	cortex_a72_cluster_pwr_dwn
diff --git a/lib/cpus/aarch64/cortex_a73.S b/lib/cpus/aarch64/cortex_a73.S
index 2dbd515..d595f12 100644
--- a/lib/cpus/aarch64/cortex_a73.S
+++ b/lib/cpus/aarch64/cortex_a73.S
@@ -187,8 +187,9 @@
 	ret
 endfunc cortex_a73_cpu_reg_dump
 
-declare_cpu_ops_workaround_cve_2017_5715 cortex_a73, CORTEX_A73_MIDR, \
+declare_cpu_ops_wa cortex_a73, CORTEX_A73_MIDR, \
 	cortex_a73_reset_func, \
 	check_errata_cve_2017_5715, \
+	CPU_NO_EXTRA2_FUNC, \
 	cortex_a73_core_pwr_dwn, \
 	cortex_a73_cluster_pwr_dwn
diff --git a/lib/cpus/aarch64/cortex_a75.S b/lib/cpus/aarch64/cortex_a75.S
index 9cc2c01..20ec32c 100644
--- a/lib/cpus/aarch64/cortex_a75.S
+++ b/lib/cpus/aarch64/cortex_a75.S
@@ -130,7 +130,8 @@
 	ret
 endfunc cortex_a75_cpu_reg_dump
 
-declare_cpu_ops_workaround_cve_2017_5715 cortex_a75, CORTEX_A75_MIDR, \
+declare_cpu_ops_wa cortex_a75, CORTEX_A75_MIDR, \
 	cortex_a75_reset_func, \
 	check_errata_cve_2017_5715, \
+	CPU_NO_EXTRA2_FUNC, \
 	cortex_a75_core_pwr_dwn
diff --git a/lib/cpus/aarch64/cpu_helpers.S b/lib/cpus/aarch64/cpu_helpers.S
index 78c66e6..69ece8f 100644
--- a/lib/cpus/aarch64/cpu_helpers.S
+++ b/lib/cpus/aarch64/cpu_helpers.S
@@ -316,3 +316,27 @@
 	mov	x0, #ERRATA_NOT_APPLIES
 	ret
 endfunc check_wa_cve_2017_5715
+
+/*
+ * void *wa_cve_2018_3639_get_disable_ptr(void);
+ *
+ * Returns a function pointer which is used to disable mitigation
+ * for CVE-2018-3639.
+ * The function pointer is only returned on cores that employ
+ * dynamic mitigation.  If the core uses static mitigation or is
+ * unaffected by CVE-2018-3639 this function returns NULL.
+ *
+ * NOTE: Must be called only after cpu_ops have been initialized
+ *       in per-CPU data.
+ */
+	.globl	wa_cve_2018_3639_get_disable_ptr
+func wa_cve_2018_3639_get_disable_ptr
+	mrs	x0, tpidr_el3
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif
+	ldr	x0, [x0, #CPU_DATA_CPU_OPS_PTR]
+	ldr	x0, [x0, #CPU_EXTRA2_FUNC]
+	ret
+endfunc wa_cve_2018_3639_get_disable_ptr
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 31cd837..434c13e 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -18,6 +18,7 @@
 
 WORKAROUND_CVE_2017_5715	?=1
 WORKAROUND_CVE_2018_3639	?=1
+DYNAMIC_WORKAROUND_CVE_2018_3639	?=0
 
 # Process SKIP_A57_L1_FLUSH_PWR_DWN flag
 $(eval $(call assert_boolean,SKIP_A57_L1_FLUSH_PWR_DWN))
@@ -39,6 +40,15 @@
 $(eval $(call assert_boolean,WORKAROUND_CVE_2018_3639))
 $(eval $(call add_define,WORKAROUND_CVE_2018_3639))
 
+$(eval $(call assert_boolean,DYNAMIC_WORKAROUND_CVE_2018_3639))
+$(eval $(call add_define,DYNAMIC_WORKAROUND_CVE_2018_3639))
+
+ifneq (${DYNAMIC_WORKAROUND_CVE_2018_3639},0)
+    ifeq (${WORKAROUND_CVE_2018_3639},0)
+        $(error "Error: WORKAROUND_CVE_2018_3639 must be 1 if DYNAMIC_WORKAROUND_CVE_2018_3639 is 1")
+    endif
+endif
+
 # CPU Errata Build flags.
 # These should be enabled by the platform if the erratum workaround needs to be
 # applied.
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S
index 121ca4d..707e6db 100644
--- a/lib/el3_runtime/aarch64/context.S
+++ b/lib/el3_runtime/aarch64/context.S
@@ -404,6 +404,15 @@
 	msr	spsr_el3, x16
 	msr	elr_el3, x17
 
+#if IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639
+	/* Restore mitigation state as it was on entry to EL3 */
+	ldr	x17, [sp, #CTX_CVE_2018_3639_OFFSET + CTX_CVE_2018_3639_DISABLE]
+	cmp	x17, xzr
+	beq	1f
+	blr	x17
+#endif
+
+1:
 	/* Restore saved general purpose registers and return */
 	b	restore_gp_registers_eret
 endfunc el3_exit