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authorDave Kleikamp <shaggy@linux.vnet.ibm.com>2011-01-26 06:17:59 +0000
committerJosh Boyer <jwboyer@linux.vnet.ibm.com>2011-02-02 06:59:02 -0500
commit21a06b0459f5e3ecdeccacfbf076c229514c1840 (patch)
tree2910d16ee073ab722e65eae7373519e64dc5179d /arch/powerpc
parentc48d0dbaac7f27c083430170c66194d6a523bc2a (diff)
downloadlinaro-lsk-21a06b0459f5e3ecdeccacfbf076c229514c1840.tar.gz
powerpc/476: Workaround for PLB6 hang
The 476FP core may hang if an instruction fetch happens during an msync following a tlbsync. This workaround makes sure that enough instruction cache lines are pre-fetched before executing the msync. (sync and msync are the same to the compiler.) Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/mm/tlb_nohash_low.S35
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/powerpc/mm/tlb_nohash_low.S b/arch/powerpc/mm/tlb_nohash_low.S
index af405eefe48..7c63c0ed4f1 100644
--- a/arch/powerpc/mm/tlb_nohash_low.S
+++ b/arch/powerpc/mm/tlb_nohash_low.S
@@ -189,6 +189,13 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
blr
#ifdef CONFIG_PPC_47x
+
+/*
+ * 47x variant of icbt
+ */
+# define ICBT(CT,RA,RB) \
+ .long 0x7c00002c | ((CT) << 21) | ((RA) << 16) | ((RB) << 11)
+
/*
* _tlbivax_bcast is only on 47x. We don't bother doing a runtime
* check though, it will blow up soon enough if we mistakenly try
@@ -206,7 +213,35 @@ _GLOBAL(_tlbivax_bcast)
isync
eieio
tlbsync
+BEGIN_FTR_SECTION
+ b 1f
+END_FTR_SECTION_IFSET(CPU_FTR_476_DD2)
+ sync
+ wrtee r10
+ blr
+/*
+ * DD2 HW could hang if in instruction fetch happens before msync completes.
+ * Touch enough instruction cache lines to ensure cache hits
+ */
+1: mflr r9
+ bl 2f
+2: mflr r6
+ li r7,32
+ ICBT(0,r6,r7) /* touch next cache line */
+ add r6,r6,r7
+ ICBT(0,r6,r7) /* touch next cache line */
+ add r6,r6,r7
+ ICBT(0,r6,r7) /* touch next cache line */
sync
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ mtlr r9
wrtee r10
blr
#endif /* CONFIG_PPC_47x */