From bac51ad9d14f6baed3730ef53bedc1eb2238563a Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu, 9 Jul 2015 00:30:24 +0100
Subject: [PATCH] ARM: invalidate L1 before enabling coherency

We must invalidate the L1 cache before enabling coherency, otherwise
secondary CPUs can inject invalid cache lines into the coherent CPU
cluster, which could then be migrated to other CPUs.  This fixes a
recent regression with SoCFPGA randomly failing to boot.

Fixes: 02b4e2756e01 ("ARM: v7 setup function should invalidate L1 cache")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mm/proc-v7.S | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 0716bbe198728..de2b246fed380 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -274,7 +274,10 @@ __v7_ca15mp_setup:
 __v7_b15mp_setup:
 __v7_ca17mp_setup:
 	mov	r10, #0
-1:
+1:	adr	r12, __v7_setup_stack		@ the local stack
+	stmia	r12, {r0-r5, lr}		@ v7_invalidate_l1 touches r0-r6
+	bl      v7_invalidate_l1
+	ldmia	r12, {r0-r5, lr}
 #ifdef CONFIG_SMP
 	ALT_SMP(mrc	p15, 0, r0, c1, c0, 1)
 	ALT_UP(mov	r0, #(1 << 6))		@ fake it for UP
@@ -283,7 +286,7 @@ __v7_ca17mp_setup:
 	orreq	r0, r0, r10			@ Enable CPU-specific SMP bits
 	mcreq	p15, 0, r0, c1, c0, 1
 #endif
-	b	__v7_setup
+	b	__v7_setup_cont
 
 /*
  * Errata:
@@ -413,10 +416,11 @@ __v7_pj4b_setup:
 
 __v7_setup:
 	adr	r12, __v7_setup_stack		@ the local stack
-	stmia	r12, {r0-r5, r7, r9, r11, lr}
+	stmia	r12, {r0-r5, lr}		@ v7_invalidate_l1 touches r0-r6
 	bl      v7_invalidate_l1
-	ldmia	r12, {r0-r5, r7, r9, r11, lr}
+	ldmia	r12, {r0-r5, lr}
 
+__v7_setup_cont:
 	and	r0, r9, #0xff000000		@ ARM?
 	teq	r0, #0x41000000
 	bne	__errata_finish
@@ -480,7 +484,7 @@ ENDPROC(__v7_setup)
 
 	.align	2
 __v7_setup_stack:
-	.space	4 * 11				@ 11 registers
+	.space	4 * 7				@ 12 registers
 
 	__INITDATA
 
-- 
GitLab