powerpc/mm: Export flush_all_mm()

With the optimizations introduced by commit a46cc7a90fd8
("powerpc/mm/radix: Improve TLB/PWC flushes"), flush_tlb_mm() no
longer flushes the page walk cache (PWC) with radix. This patch
introduces flush_all_mm(), which flushes everything, TLB and PWC, for
a given mm.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-By: Alistair Popple <alistair@popple.id.au>
[mpe: Add a WARN_ON_ONCE() in the empty hash routines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 22 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
index 2f6373144e2c..99c99bb04353 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
@@ -65,6 +65,28 @@ static inline void hash__flush_tlb_mm(struct mm_struct *mm)
 {
 }
 
+static inline void hash__local_flush_all_mm(struct mm_struct *mm)
+{
+	/*
+	 * There's no Page Walk Cache for hash, so what is needed is
+	 * the same as flush_tlb_mm(), which doesn't really make sense
+	 * with hash. So the only thing we could do is flush the
+	 * entire LPID! Punt for now, as it's not being used.
+	 */
+	WARN_ON_ONCE(1);
+}
+
+static inline void hash__flush_all_mm(struct mm_struct *mm)
+{
+	/*
+	 * There's no Page Walk Cache for hash, so what is needed is
+	 * the same as flush_tlb_mm(), which doesn't really make sense
+	 * with hash. So the only thing we could do is flush the
+	 * entire LPID! Punt for now, as it's not being used.
+	 */
+	WARN_ON_ONCE(1);
+}
+
 static inline void hash__local_flush_tlb_page(struct vm_area_struct *vma,
 					  unsigned long vmaddr)
 {