powerpc/mm: Add support for SPARSEMEM_VMEMMAP on 64-bit Book3E

The base TLB support didn't include support for SPARSEMEM_VMEMMAP, though
we did carve out some virtual space for it, the necessary support code
wasn't there. This implements it by using 16M pages for now, though the
page size could easily be changed at runtime if necessary.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 5961c6b739dd..d2e5321d5ea6 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -121,7 +121,12 @@ extern unsigned int rtas_data, rtas_size;
 struct hash_pte;
 extern struct hash_pte *Hash, *Hash_end;
 extern unsigned long Hash_size, Hash_mask;
-#endif
+
+#endif /* CONFIG_PPC32 */
+
+#ifdef CONFIG_PPC64
+extern int map_kernel_page(unsigned long ea, unsigned long pa, int flags);
+#endif /* CONFIG_PPC64 */
 
 extern unsigned long ioremap_bot;
 extern unsigned long __max_low_memory;