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>
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index dc82dcd..c073de4 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -46,6 +46,12 @@
*/
#define MMU_FTR_LOCK_BCAST_INVAL ASM_CONST(0x00100000)
+/* This indicates that the processor doesn't handle way selection
+ * properly and needs SW to track and update the LRU state. This
+ * is specific to an errata on e300c2/c3/c4 class parts
+ */
+#define MMU_FTR_NEED_DTLB_SW_LRU ASM_CONST(0x00200000)
+
#ifndef __ASSEMBLY__
#include <asm/cputable.h>