1 files changed, 27 insertions, 1 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 18201e9e8cc7..a92738e8b1eb 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -152,7 +152,33 @@ alternative_else
 alternative_endif
 ENDPROC(cpu_do_switch_mm)
 
-	.section ".text.init", #alloc, #execinstr
+	.pushsection ".idmap.text", "ax"
+/*
+ * void idmap_cpu_replace_ttbr1(phys_addr_t new_pgd)
+ *
+ * This is the low-level counterpart to cpu_replace_ttbr1, and should not be
+ * called by anything else. It can only be executed from a TTBR0 mapping.
+ */
+ENTRY(idmap_cpu_replace_ttbr1)
+	mrs	x2, daif
+	msr	daifset, #0xf
+
+	adrp	x1, empty_zero_page
+	msr	ttbr1_el1, x1
+	isb
+
+	tlbi	vmalle1
+	dsb	nsh
+	isb
+
+	msr	ttbr1_el1, x0
+	isb
+
+	msr	daif, x2
+
+	ret
+ENDPROC(idmap_cpu_replace_ttbr1)
+	.popsection
 
 /*
  *	__cpu_setup