From dcc87dd58db466caa2d66755c5ec9455edf42fe8 Mon Sep 17 00:00:00 2001
From: Scott Wood <scottwood@freescale.com>
Date: Thu, 20 Aug 2009 17:45:05 -0500
Subject: [PATCH] ppc/85xx: Ensure that MAS8 is zero when writing TLB entries.
Its reset value is random, and we sometimes read uninitialized TLB
arrays. Make sure that we don't retain MAS8 from reading such an entry
if the VF bit in MAS8 is set, attempts to use the mapping will trap.
Signed-off-by: Scott Wood <scottwood@freescale.com>
---
cpu/mpc85xx/start.S | 4 ++++
cpu/mpc85xx/tlb.c | 3 +++
include/asm-ppc/processor.h | 2 ++
3 files changed, 9 insertions(+)
diff --git a/cpu/mpc85xx/start.S b/cpu/mpc85xx/start.S
index eaed0e0be5..7a23b4f811 100644
--- a/cpu/mpc85xx/start.S
+++ b/cpu/mpc85xx/start.S
@@ -156,6 +156,10 @@ _start_e500:
mtspr MCSR,r0 /* machine check syndrome register */
mtxer r0 /* clear integer exception register */
+#ifdef CONFIG_SYS_BOOK3E_HV
+ mtspr MAS8,r0 /* make sure MAS8 is clear */
+#endif
+
/* Enable Time Base and Select Time Base Clock */
lis r0,HID0_EMCP@h /* Enable machine check */
#if defined(CONFIG_ENABLE_36BIT_PHYS)
diff --git a/cpu/mpc85xx/tlb.c b/cpu/mpc85xx/tlb.c
index 0497a29ba8..03c2449b5c 100644
--- a/cpu/mpc85xx/tlb.c
+++ b/cpu/mpc85xx/tlb.c
@@ -50,6 +50,9 @@ void set_tlb(u8 tlb, u32 epn, u64 rpn,
mtspr(MAS3, _mas3);
#ifdef CONFIG_ENABLE_36BIT_PHYS
mtspr(MAS7, _mas7);
+#endif
+#ifdef CONFIG_SYS_BOOK3E_HV
+ mtspr(MAS8, 0);
#endif
asm volatile("isync;msync;tlbwe;isync");
diff --git a/include/asm-ppc/processor.h b/include/asm-ppc/processor.h
index 0a4c66c9d9..3764a5a51d 100644
--- a/include/asm-ppc/processor.h
+++ b/include/asm-ppc/processor.h
@@ -518,6 +518,7 @@
#define SPRN_MAS5 0x275 /* MMU Assist Register 5 */
#define SPRN_MAS6 0x276 /* MMU Assist Register 6 */
#define SPRN_MAS7 0x3B0 /* MMU Assist Register 7 */
+#define SPRN_MAS8 0x155 /* MMU Assist Register 8 */
#define SPRN_IVOR32 0x210 /* Interrupt Vector Offset Register 32 */
#define SPRN_IVOR33 0x211 /* Interrupt Vector Offset Register 33 */
@@ -720,6 +721,7 @@
#define MAS5 SPRN_MAS5
#define MAS6 SPRN_MAS6
#define MAS7 SPRN_MAS7
+#define MAS8 SPRN_MAS8
#if defined(CONFIG_4xx) || defined(CONFIG_44x) || defined(CONFIG_MPC85xx)
#define DAR_DEAR DEAR
--
2.39.5