powerpc/mm: Add SMP support to no-hash TLB handling

This commit moves the whole no-hash TLB handling out of line into a
new tlb_nohash.c file, and implements some basic SMP support using
IPIs and/or broadcast tlbivax instructions.

Note that I'm using local invalidations for D->I cache coherency.

At worst, if another processor is trying to execute the same and
has the old entry in its TLB, it will just take a fault and re-do
the TLB flush locally (it won't re-do the cache flush in any case).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index dc8c0ae..6e76399 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -30,6 +30,22 @@
  */
 #define MMU_FTR_BIG_PHYS		ASM_CONST(0x00020000)
 
+/* Enable use of broadcast TLB invalidations. We don't always set it
+ * on processors that support it due to other constraints with the
+ * use of such invalidations
+ */
+#define MMU_FTR_USE_TLBIVAX_BCAST	ASM_CONST(0x00040000)
+
+/* Enable use of tlbilx invalidate-by-PID variant.
+ */
+#define MMU_FTR_USE_TLBILX_PID		ASM_CONST(0x00080000)
+
+/* This indicates that the processor cannot handle multiple outstanding
+ * broadcast tlbivax or tlbsync. This makes the code use a spinlock
+ * around such invalidate forms.
+ */
+#define MMU_FTR_LOCK_BCAST_INVAL	ASM_CONST(0x00100000)
+
 #ifndef __ASSEMBLY__
 #include <asm/cputable.h>