From 2319f1239592d0de80414ad2338c2bd7384a2a41 Mon Sep 17 00:00:00 2001
From: Kumar Gala <galak@kernel.crashing.org>
Date: Thu, 19 Mar 2009 03:55:41 +0000
Subject: powerpc/mm: e300c2/c3/c4 TLB errata workaround

Complete workaround for DTLB errata in e300c2/c3/c4 processors.

Due to the bug, the hardware-implemented LRU algorythm always goes to way
1 of the TLB. This fix implements the proposed software workaround in
form of a LRW table for chosing the TLB-way.

Based on patch from David Jander <david@protonic.nl>

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/cpu_setup_6xx.S | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'arch/powerpc/kernel/cpu_setup_6xx.S')

diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S
index 72d1d7395254..54f767e31a1a 100644
--- a/arch/powerpc/kernel/cpu_setup_6xx.S
+++ b/arch/powerpc/kernel/cpu_setup_6xx.S
@@ -15,9 +15,14 @@
 #include <asm/ppc_asm.h>
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
+#include <asm/mmu.h>
 
 _GLOBAL(__setup_cpu_603)
 	mflr	r4
+BEGIN_MMU_FTR_SECTION
+	li	r10,0
+	mtspr	SPRN_SPRG4,r10		/* init SW LRU tracking */
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
 BEGIN_FTR_SECTION
 	bl	__init_fpu_registers
 END_FTR_SECTION_IFCLR(CPU_FTR_FPU_UNAVAILABLE)
-- 
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