From: Ard Biesheuvel <ardb@kernel.org>
Date: Mon, 14 Sep 2020 08:25:29 +0000 (+0300)
Subject: ARM: head: use PC-relative insn sequence for __smp_alt
X-Git-Tag: submit/tizen/20220208.074352~475
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a50f65b892da3a231d7bee31cd8da38a13744599;p=platform%2Fkernel%2Flinux-rpi.git

ARM: head: use PC-relative insn sequence for __smp_alt

commit 59d2f2827dfdccf8911d5e51465136b52ba623c4 upstream.

Now that calling __do_fixup_smp_on_up() can be done without passing
the physical-to-virtual offset in r3, we can replace the open coded
PC relative offset calculations with a pair of adr_l invocations. This
removes some open coded arithmetic involving virtual addresses, avoids
literal pools on v7+, and slightly reduces the footprint of the code.

Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index e87e087..7adab03 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -519,19 +519,11 @@ ARM_BE8(rev	r0, r0)			@ byteswap if big endian
 	retne	lr
 
 __fixup_smp_on_up:
-	adr	r0, 1f
-	ldmia	r0, {r3 - r5}
-	sub	r3, r0, r3
-	add	r4, r4, r3
-	add	r5, r5, r3
+	adr_l	r4, __smpalt_begin
+	adr_l	r5, __smpalt_end
 	b	__do_fixup_smp_on_up
 ENDPROC(__fixup_smp)
 
-	.align
-1:	.word	.
-	.word	__smpalt_begin
-	.word	__smpalt_end
-
 	.pushsection .data
 	.align	2
 	.globl	smp_on_up