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Diffstat (limited to 'arch/ppc/kernel/l2cr.S')
-rw-r--r--arch/ppc/kernel/l2cr.S31
1 files changed, 30 insertions, 1 deletions
diff --git a/arch/ppc/kernel/l2cr.S b/arch/ppc/kernel/l2cr.S
index c3944104826..861115249b3 100644
--- a/arch/ppc/kernel/l2cr.S
+++ b/arch/ppc/kernel/l2cr.S
@@ -156,6 +156,26 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
The bit moved on the 7450.....
****/
+BEGIN_FTR_SECTION
+ /* Disable L2 prefetch on some 745x and try to ensure
+ * L2 prefetch engines are idle. As explained by errata
+ * text, we can't be sure they are, we just hope very hard
+ * that well be enough (sic !). At least I noticed Apple
+ * doesn't even bother doing the dcbf's here...
+ */
+ mfspr r4,SPRN_MSSCR0
+ rlwinm r4,r4,0,0,29
+ sync
+ mtspr SPRN_MSSCR0,r4
+ sync
+ isync
+ lis r4,KERNELBASE@h
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+ dcbf 0,r4
+END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
+
/* TODO: use HW flush assist when available */
lis r4,0x0002
@@ -230,7 +250,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
oris r3,r3,0x8000
mtspr SPRN_L2CR,r3
sync
-
+
+ /* Enable L2 HW prefetch on 744x/745x */
+BEGIN_FTR_SECTION
+ mfspr r3,SPRN_MSSCR0
+ ori r3,r3,3
+ sync
+ mtspr SPRN_MSSCR0,r3
+ sync
+ isync
+END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
4:
/* Restore HID0[DPM] to whatever it was before */