diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h
index 101d60f16d466382608bad941482d3544d13ccfb..820169bac6c4e336a62d7e15ffdfb4dbfb4cf0db 100644
--- a/arch/powerpc/include/asm/book3s/64/kup-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h
@@ -62,9 +62,9 @@
 #include <asm/mmu.h>
 #include <asm/ptrace.h>
 
-static inline void kuap_restore_amr(struct pt_regs *regs)
+static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
 {
-	if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) {
+	if (mmu_has_feature(MMU_FTR_RADIX_KUAP) && unlikely(regs->kuap != amr)) {
 		isync();
 		mtspr(SPRN_AMR, regs->kuap);
 		/*
@@ -75,6 +75,17 @@ static inline void kuap_restore_amr(struct pt_regs *regs)
 	}
 }
 
+static inline unsigned long kuap_get_and_check_amr(void)
+{
+	if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) {
+		unsigned long amr = mfspr(SPRN_AMR);
+		if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
+			WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
+		return amr;
+	}
+	return 0;
+}
+
 static inline void kuap_check_amr(void)
 {
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_RADIX_KUAP))
@@ -151,13 +162,18 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
 }
 #else /* CONFIG_PPC_KUAP */
-static inline void kuap_restore_amr(struct pt_regs *regs)
+static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
 {
 }
 
 static inline void kuap_check_amr(void)
 {
 }
+
+static inline unsigned long kuap_get_and_check_amr(void)
+{
+	return 0;
+}
 #endif /* CONFIG_PPC_KUAP */
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 613da0d0fa8cb6551dde3763e4f7f6b41e127715..79edba3ab3124a2df72c77c07f025b9cacf66a98 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -242,6 +242,10 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 	BUG_ON(!FULL_REGS(regs));
 	BUG_ON(regs->softe != IRQS_ENABLED);
 
+	/*
+	 * We don't need to restore AMR on the way back to userspace for KUAP.
+	 * AMR can only have been unlocked if we interrupted the kernel.
+	 */
 	kuap_check_amr();
 
 	local_irq_save(flags);
@@ -313,13 +317,14 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
 	unsigned long *ti_flagsp = &current_thread_info()->flags;
 	unsigned long flags;
 	unsigned long ret = 0;
+	unsigned long amr;
 
 	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && unlikely(!(regs->msr & MSR_RI)))
 		unrecoverable_exception(regs);
 	BUG_ON(regs->msr & MSR_PR);
 	BUG_ON(!FULL_REGS(regs));
 
-	kuap_check_amr();
+	amr = kuap_get_and_check_amr();
 
 	if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) {
 		clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp);
@@ -367,10 +372,11 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
 #endif
 
 	/*
-	 * We don't need to restore AMR on the way back to userspace for KUAP.
-	 * The value of AMR only matters while we're in the kernel.
+	 * Don't want to mfspr(SPRN_AMR) here, because this comes after mtmsr,
+	 * which would cause Read-After-Write stalls. Hence, we take the AMR
+	 * value from the check above.
 	 */
-	kuap_restore_amr(regs);
+	kuap_restore_amr(regs, amr);
 
 	return ret;
 }