summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
Diffstat (limited to 'arch')
-rw-r--r--arch/ppc/kernel/cpu_setup_6xx.S5
-rw-r--r--arch/ppc/kernel/l2cr.S31
2 files changed, 34 insertions, 2 deletions
diff --git a/arch/ppc/kernel/cpu_setup_6xx.S b/arch/ppc/kernel/cpu_setup_6xx.S
index 468721d9ebd2..3fb1fb619d2c 100644
--- a/arch/ppc/kernel/cpu_setup_6xx.S
+++ b/arch/ppc/kernel/cpu_setup_6xx.S
@@ -249,8 +249,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_NO_DPM)
sync
isync
- /* Enable L2 HW prefetch
+ /* Enable L2 HW prefetch, if L2 is enabled
*/
+ mfspr r3,SPRN_L2CR
+ andis. r3,r3,L2CR_L2E@h
+ beqlr
mfspr r3,SPRN_MSSCR0
ori r3,r3,3
sync
diff --git a/arch/ppc/kernel/l2cr.S b/arch/ppc/kernel/l2cr.S
index c39441048266..861115249b35 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 */