diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h
new file mode 100644
index 000000000000..93273ca99310
--- /dev/null
+++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KUP_RADIX_H
+#define _ASM_POWERPC_KUP_RADIX_H
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_PPC_KUAP
+#include <asm/reg.h>
+/*
+ * We do have the ability to individually lock/unlock reads and writes rather
+ * than both at once, however it's a significant performance hit due to needing
+ * to do a read-modify-write, which adds a mfspr, which is slow.  As a result,
+ * locking/unlocking both at once is preferred.
+ */
+static inline void unlock_user_access(void __user *to, const void __user *from,
+				      unsigned long size)
+{
+	if (!mmu_has_feature(MMU_FTR_RADIX_KUAP))
+		return;
+
+	mtspr(SPRN_AMR, 0);
+	isync();
+	get_paca()->user_access_allowed = 1;
+}
+
+static inline void lock_user_access(void __user *to, const void __user *from,
+				    unsigned long size)
+{
+	if (!mmu_has_feature(MMU_FTR_RADIX_KUAP))
+		return;
+
+	mtspr(SPRN_AMR, AMR_LOCKED);
+	get_paca()->user_access_allowed = 0;
+}
+#endif /* CONFIG_PPC_KUAP */
+#endif /* __ASSEMBLY__ */
+#endif
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 4d971ca1e69b..0ed4923c1282 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -264,8 +264,19 @@ BEGIN_FTR_SECTION_NESTED(943)						\
 	std	ra,offset(r13);						\
 END_FTR_SECTION_NESTED(ftr,ftr,943)
 
-#define LOCK_USER_ACCESS(reg)
-#define UNLOCK_USER_ACCESS(reg)
+#define LOCK_USER_ACCESS(reg)						\
+BEGIN_MMU_FTR_SECTION_NESTED(944)					\
+	lis	reg,(AMR_LOCKED)@highest;				\
+	rldicr	reg,reg,32,31;						\
+	mtspr	SPRN_AMR,reg;						\
+END_MMU_FTR_SECTION_NESTED(MMU_FTR_RADIX_KUAP,MMU_FTR_RADIX_KUAP,944)
+
+#define UNLOCK_USER_ACCESS(reg)						\
+BEGIN_MMU_FTR_SECTION_NESTED(945)					\
+	li	reg,0;							\
+	mtspr	SPRN_AMR,reg;						\
+	isync;								\
+END_MMU_FTR_SECTION_NESTED(MMU_FTR_RADIX_KUAP,MMU_FTR_RADIX_KUAP,945)
 
 #define EXCEPTION_PROLOG_0(area)					\
 	GET_PACA(r13);							\
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 16ff3f9da29c..7813e2bcfb7c 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -8,6 +8,9 @@
 #ifdef CONFIG_PPC_BOOK3S_32
 #include <asm/book3s/32/kup.h>
 #endif
+#ifdef CONFIG_PPC_BOOK3S_64
+#include <asm/book3s/64/kup-radix.h>
+#endif
 
 #ifndef __ASSEMBLY__
 
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index eb20eb3b8fb0..048df188fc10 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -107,6 +107,10 @@
  */
 #define MMU_FTR_1T_SEGMENT		ASM_CONST(0x40000000)
 
+/* Supports KUAP (key 0 controlling userspace addresses) on radix
+ */
+#define MMU_FTR_RADIX_KUAP		ASM_CONST(0x80000000)
+
 /* MMU feature bit sets for various CPUs */
 #define MMU_FTRS_DEFAULT_HPTE_ARCH_V2	\
 	MMU_FTR_HPTE_TABLE | MMU_FTR_PPCAS_ARCH_V2
@@ -143,7 +147,10 @@ enum {
 		MMU_FTR_KERNEL_RO | MMU_FTR_68_BIT_VA |
 #ifdef CONFIG_PPC_RADIX_MMU
 		MMU_FTR_TYPE_RADIX |
-#endif
+#ifdef CONFIG_PPC_KUAP
+		MMU_FTR_RADIX_KUAP |
+#endif /* CONFIG_PPC_KUAP */
+#endif /* CONFIG_PPC_RADIX_MMU */
 		0,
 };
 
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index c9c382e57017..6b5d2a61af5a 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -246,6 +246,7 @@
 #define SPRN_DSCR	0x11
 #define SPRN_CFAR	0x1c	/* Come From Address Register */
 #define SPRN_AMR	0x1d	/* Authority Mask Register */
+#define   AMR_LOCKED	0xC000000000000000UL /* Read & Write disabled */
 #define SPRN_UAMOR	0x9d	/* User Authority Mask Override Register */
 #define SPRN_AMOR	0x15d	/* Authority Mask Override Register */
 #define SPRN_ACOP	0x1F	/* Available Coprocessor Register */
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 3565e266994b..e248f330d6fd 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -29,6 +29,7 @@
 #include <asm/powernv.h>
 #include <asm/sections.h>
 #include <asm/trace.h>
+#include <asm/uaccess.h>
 
 #include <trace/events/thp.h>
 
@@ -552,6 +553,19 @@ void __init setup_kuep(bool disabled)
 }
 #endif
 
+#ifdef CONFIG_PPC_KUAP
+void __init setup_kuap(bool disabled)
+{
+	if (disabled || !early_radix_enabled())
+		return;
+
+	pr_info("Activating Kernel Userspace Access Prevention\n");
+
+	cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
+	mtspr(SPRN_AMR, AMR_LOCKED);
+}
+#endif
+
 void __init radix__early_init_mmu(void)
 {
 	unsigned long lpcr;
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index b271b283c785..bb3cf915016f 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -7,6 +7,7 @@
 
 #include <asm/mman.h>
 #include <asm/setup.h>
+#include <asm/uaccess.h>
 #include <linux/pkeys.h>
 #include <linux/of_device.h>
 
@@ -266,7 +267,8 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 
 void thread_pkey_regs_save(struct thread_struct *thread)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (static_branch_likely(&pkey_disabled) &&
+	    !mmu_has_feature(MMU_FTR_RADIX_KUAP))
 		return;
 
 	/*
@@ -280,7 +282,8 @@ void thread_pkey_regs_save(struct thread_struct *thread)
 void thread_pkey_regs_restore(struct thread_struct *new_thread,
 			      struct thread_struct *old_thread)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (static_branch_likely(&pkey_disabled) &&
+	    !mmu_has_feature(MMU_FTR_RADIX_KUAP))
 		return;
 
 	if (old_thread->amr != new_thread->amr)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 48cc8df0fdd2..0b9a8eda413a 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -336,6 +336,7 @@ config PPC_RADIX_MMU
 	depends on PPC_BOOK3S_64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select PPC_HAVE_KUEP
+	select PPC_HAVE_KUAP
 	default y
 	help
 	  Enable support for the Power ISA 3.0 Radix style MMU. Currently this
