arm64: head.S: cleanup SCTLR_ELx initialization

Let's make SCTLR_ELx initialization a bit clearer by using meaningful
names for the initialization values, following the same scheme for
SCTLR_EL1 and SCTLR_EL2.

These definitions will be used more widely in subsequent patches.

There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201113124937.20574-5-mark.rutland@arm.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/sysreg.h

@@ -582,6 +582,9 @@
 #define ENDIAN_SET_EL2		0
 #endif
 
+#define INIT_SCTLR_EL2_MMU_OFF \
+	(SCTLR_EL2_RES1 | ENDIAN_SET_EL2)
+
 /* SCTLR_EL1 specific flags. */
 #define SCTLR_EL1_ATA0		(BIT(42))
 
@@ -615,12 +618,15 @@
 #define ENDIAN_SET_EL1		0
 #endif
 
-#define SCTLR_EL1_SET	(SCTLR_ELx_M    | SCTLR_ELx_C    | SCTLR_ELx_SA   |\
-			 SCTLR_EL1_SA0  | SCTLR_EL1_SED  | SCTLR_ELx_I    |\
-			 SCTLR_EL1_DZE  | SCTLR_EL1_UCT                   |\
-			 SCTLR_EL1_NTWE | SCTLR_ELx_IESB | SCTLR_EL1_SPAN |\
-			 SCTLR_ELx_ITFSB| SCTLR_ELx_ATA  | SCTLR_EL1_ATA0 |\
-			 ENDIAN_SET_EL1 | SCTLR_EL1_UCI  | SCTLR_EL1_RES1)
+#define INIT_SCTLR_EL1_MMU_OFF \
+	(ENDIAN_SET_EL1 | SCTLR_EL1_RES1)
+
+#define INIT_SCTLR_EL1_MMU_ON \
+	(SCTLR_ELx_M    | SCTLR_ELx_C    | SCTLR_ELx_SA   | SCTLR_EL1_SA0   | \
+	 SCTLR_EL1_SED  | SCTLR_ELx_I    | SCTLR_EL1_DZE  | SCTLR_EL1_UCT   | \
+	 SCTLR_EL1_NTWE | SCTLR_ELx_IESB | SCTLR_EL1_SPAN | SCTLR_ELx_ITFSB | \
+	 SCTLR_ELx_ATA  | SCTLR_EL1_ATA0 | ENDIAN_SET_EL1 | SCTLR_EL1_UCI   | \
+	 SCTLR_EL1_RES1)
 
 /* MAIR_ELx memory attributes (used by Linux) */
 #define MAIR_ATTR_DEVICE_nGnRnE		UL(0x00)

arch/arm64/kernel/head.S

@@ -494,13 +494,13 @@ SYM_FUNC_START(init_kernel_el)
 	mrs	x0, CurrentEL
 	cmp	x0, #CurrentEL_EL2
 	b.eq	1f
-	mov_q	x0, (SCTLR_EL1_RES1 | ENDIAN_SET_EL1)
+	mov_q	x0, INIT_SCTLR_EL1_MMU_OFF
 	msr	sctlr_el1, x0
 	mov	w0, #BOOT_CPU_MODE_EL1		// This cpu booted in EL1
 	isb
 	ret
 
-1:	mov_q	x0, (SCTLR_EL2_RES1 | ENDIAN_SET_EL2)
+1:	mov_q	x0, INIT_SCTLR_EL2_MMU_OFF
 	msr	sctlr_el2, x0
 
 #ifdef CONFIG_ARM64_VHE
@@ -621,7 +621,7 @@ SYM_INNER_LABEL(install_el2_stub, SYM_L_LOCAL)
 	 * requires no configuration, and all non-hyp-specific EL2 setup
 	 * will be done via the _EL1 system register aliases in __cpu_setup.
 	 */
-	mov_q	x0, (SCTLR_EL1_RES1 | ENDIAN_SET_EL1)
+	mov_q	x0, INIT_SCTLR_EL1_MMU_OFF
 	msr	sctlr_el1, x0
 
 	/* Coprocessor traps. */

arch/arm64/mm/proc.S

@@ -489,6 +489,6 @@ SYM_FUNC_START(__cpu_setup)
 	/*
 	 * Prepare SCTLR
 	 */
-	mov_q	x0, SCTLR_EL1_SET
+	mov_q	x0, INIT_SCTLR_EL1_MMU_ON
 	ret					// return to head.S
 SYM_FUNC_END(__cpu_setup)