[PATCH v2 06/29] ARM: head.S: use PC-relative insn sequence for secondary_data

[ard.biesheuvel@linaro.org (Ard Biesheuvel)]

Replace the open coded PC relative offset calculations with adr_l
and ldr_l invocations. This ensures these quantities are invariant
under runtime relocation.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 arch/arm/kernel/head.S | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 0a98aec0e39d..6e9df3663a57 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -386,10 +386,8 @@ ENTRY(secondary_startup)
 	/*
 	 * Use the page tables supplied from  __cpu_up.
 	 */
-	adr	r4, __secondary_data
-	ldmia	r4, {r5, r7, r12}		@ address to jump to after
-	sub	lr, r4, r5			@ mmu has been enabled
-	add	r3, r7, lr
+	adr_l	r3, secondary_data
+	mov_l	r12, __secondary_switched
 	ldrd	r4, [r3, #0]			@ get secondary_data.pgdir
 ARM_BE8(eor	r4, r4, r5)			@ Swap r5 and r4 in BE:
 ARM_BE8(eor	r5, r4, r5)			@ it can be done in 3 steps
@@ -404,22 +402,13 @@ ARM_BE8(eor	r4, r4, r5)			@ without using a temp reg.
 ENDPROC(secondary_startup)
 ENDPROC(secondary_startup_arm)
 
-	/*
-	 * r6  = &secondary_data
-	 */
 ENTRY(__secondary_switched)
-	ldr	sp, [r7, #12]			@ get secondary_data.stack
+	ldr_l	r7, secondary_data + 12		@ get secondary_data.stack
+	mov	sp, r7
 	mov	fp, #0
 	b	secondary_start_kernel
 ENDPROC(__secondary_switched)
 
-	.align
-
-	.type	__secondary_data, %object
-__secondary_data:
-	.long	.
-	.long	secondary_data
-	.long	__secondary_switched
 #endif /* defined(CONFIG_SMP) */
 
 
-- 
2.11.0