summary refs log tree commit diff
path: root/arch/arm
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/Kconfig9
-rw-r--r--arch/arm/mm/proc-v7.S14
2 files changed, 22 insertions, 1 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 57562f8d1f92..bd2709d55678 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1373,6 +1373,15 @@ config ARM_ERRATA_798181
 	  which sends an IPI to the CPUs that are running the same ASID
 	  as the one being invalidated.
 
+config ARM_ERRATA_773022
+	bool "ARM errata: incorrect instructions may be executed from loop buffer"
+	depends on CPU_V7
+	help
+	  This option enables the workaround for the 773022 Cortex-A15
+	  (up to r0p4) erratum. In certain rare sequences of code, the
+	  loop buffer may deliver incorrect instructions. This
+	  workaround disables the loop buffer to avoid the erratum.
+
 endmenu
 
 source "arch/arm/common/Kconfig"
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 5c6d5a3050ea..e7d45d529a21 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -329,7 +329,19 @@ __v7_setup:
 1:
 #endif
 
-3:	mov	r10, #0
+	/* Cortex-A15 Errata */
+3:	ldr	r10, =0x00000c0f		@ Cortex-A15 primary part number
+	teq	r0, r10
+	bne	4f
+
+#ifdef CONFIG_ARM_ERRATA_773022
+	cmp	r6, #0x4			@ only present up to r0p4
+	mrcle	p15, 0, r10, c1, c0, 1		@ read aux control register
+	orrle	r10, r10, #1 << 1		@ disable loop buffer
+	mcrle	p15, 0, r10, c1, c0, 1		@ write aux control register
+#endif
+
+4:	mov	r10, #0
 	mcr	p15, 0, r10, c7, c5, 0		@ I+BTB cache invalidate
 	dsb
 #ifdef CONFIG_MMU