arm64: enable Permission Indirection Extension (PIE)

Now that the necessary changes have been made, set the Permission Indirection
registers and enable the Permission Indirection Extension.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230606145859.697944-17-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: jgouly

arch/arm64/mm/proc.S

@@ -454,6 +454,21 @@ SYM_FUNC_START(__cpu_setup)
 #endif	/* CONFIG_ARM64_HW_AFDBM */
 	msr	mair_el1, mair
 	msr	tcr_el1, tcr
+
+	mrs_s	x1, SYS_ID_AA64MMFR3_EL1
+	ubfx	x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4
+	cbz	x1, .Lskip_indirection
+
+	mov_q	x0, PIE_E0
+	msr	REG_PIRE0_EL1, x0
+	mov_q	x0, PIE_E1
+	msr	REG_PIR_EL1, x0
+
+	mov	x0, TCR2_EL1x_PIE
+	msr	REG_TCR2_EL1, x0
+
+.Lskip_indirection:
+
 	/*
 	 * Prepare SCTLR
 	 */