Subject: fix ls store access with 64k mappings

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is also part of the latest patch posted to cbe-oss-dev.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

Index: linux-2.6/arch/powerpc/mm/hash_utils_64.c
===================================================================
--- linux-2.6.orig/arch/powerpc/mm/hash_utils_64.c
+++ linux-2.6/arch/powerpc/mm/hash_utils_64.c
@@ -698,6 +698,15 @@ int hash_page(unsigned long ea, unsigned
 	}
 #endif /* CONFIG_HUGETLB_PAGE */
 
+#ifndef CONFIG_PPC_64K_PAGES
+	/* If we use 4K pages and our psize is not 4K, then we are hitting
+	 * a special driver mapping, we need to align the address before
+	 * we fetch the PTE
+	 */
+	if (psize != MMU_PAGE_4K)
+		ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
+#endif /* CONFIG_PPC_64K_PAGES */
+
 	/* Get PTE and page size from page tables */
 	ptep = find_linux_pte(pgdir, ea);
 	if (ptep == NULL || !pte_present(*ptep)) {