[PATCH v2] i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472
Eric Bénard
eric at eukrea.com
Tue Oct 5 08:00:12 EDT 2010
Without this exiting WFI can result in cache corruption.
Code taken from Freescale's 2.6.27 BSP and tested on i.MX35
Signed-off-by: Eric Bénard <eric at eukrea.com>
---
v2 : use cpu_ismx3x() and add comments.
arch/arm/plat-mxc/include/mach/system.h | 32 ++++++++++++++++++++++++++++--
1 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/arch/arm/plat-mxc/include/mach/system.h b/arch/arm/plat-mxc/include/mach/system.h
index 4acd114..70e66d3 100644
--- a/arch/arm/plat-mxc/include/mach/system.h
+++ b/arch/arm/plat-mxc/include/mach/system.h
@@ -1,7 +1,7 @@
/*
* Copyright (C) 1999 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
- * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -28,8 +28,34 @@ static inline void arch_idle(void)
mxc91231_prepare_idle();
}
#endif
-
- cpu_do_idle();
+ /* fix i.MX31 errata TLSbo65953 and i.MX35 errata ENGcm09472 */
+ if (cpu_is_mx31() || cpu_is_mx35()) {
+ unsigned long reg = 0;
+ __asm__ __volatile__(
+ /* disable I and D cache */
+ "mrc p15, 0, %0, c1, c0, 0\n"
+ "bic %0, %0, #0x00001000\n"
+ "bic %0, %0, #0x00000004\n"
+ "mcr p15, 0, %0, c1, c0, 0\n"
+ /* invalidate I cache */
+ "mov %0, #0\n"
+ "mcr p15, 0, %0, c7, c5, 0\n"
+ /* clear and invalidate D cache */
+ "mov %0, #0\n"
+ "mcr p15, 0, %0, c7, c14, 0\n"
+ /* WFI */
+ "mov %0, #0\n"
+ "mcr p15, 0, %0, c7, c0, 4\n"
+ "nop\n" "nop\n" "nop\n" "nop\n"
+ "nop\n" "nop\n" "nop\n"
+ /* enable I and D cache */
+ "mrc p15, 0, %0, c1, c0, 0\n"
+ "orr %0, %0, #0x00001000\n"
+ "orr %0, %0, #0x00000004\n"
+ "mcr p15, 0, %0, c1, c0, 0\n"
+ :: "r" (reg));
+ } else
+ cpu_do_idle();
}
void arch_reset(char mode, const char *cmd);
--
1.7.0.4
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