---
  arch/arm64/kernel/cpu_errata.c |  2 ++
  arch/arm64/kernel/entry.S      | 11 +++++++----
  2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 46b3aafb631a..0288d6cf560e 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c

@@ -233,6 +233,8 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
  #endif	/* CONFIG_HARDEN_BRANCH_PREDICTOR */
  
  #ifdef CONFIG_ARM64_SSBD
+DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
+
  void __init arm64_update_smccc_conduit(struct alt_instr *alt,
  				       __le32 *origptr, __le32 *updptr,
  				       int nr_inst)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index f33e6aed3037..29ad672a6abd 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S

@@ -140,8 +140,10 @@ alternative_else_nop_endif
  
  	// This macro corrupts x0-x3. It is the caller's duty
  	// to save/restore them if required.
-	.macro	apply_ssbd, state
+	.macro	apply_ssbd, state, targ, tmp1, tmp2
  #ifdef CONFIG_ARM64_SSBD
+	ldr_this_cpu	\tmp2, arm64_ssbd_callback_required, \tmp1
+	cbz	\tmp2, \targ
  	mov	w0, #ARM_SMCCC_ARCH_WORKAROUND_2
  	mov	w1, #\state
  alternative_cb	arm64_update_smccc_conduit

@@ -176,12 +178,13 @@ alternative_cb_end
  	ldr	x19, [tsk, #TSK_TI_FLAGS]	// since we can unmask debug
  	disable_step_tsk x19, x20		// exceptions when scheduling.
  
-	apply_ssbd 1
+	apply_ssbd 1, 1f, x22, x23
  
  #ifdef CONFIG_ARM64_SSBD
  	ldp	x0, x1, [sp, #16 * 0]
  	ldp	x2, x3, [sp, #16 * 1]
  #endif
+1:
  
  	mov	x29, xzr			// fp pointed to user-space
  	.else

@@ -323,8 +326,8 @@ alternative_if ARM64_WORKAROUND_845719
  alternative_else_nop_endif
  #endif
  3:
-	apply_ssbd 0
-
+	apply_ssbd 0, 5f, x0, x1
+5:
  	.endif
  
  	msr	elr_el1, x21			// set up the return data