powerpc/mm: Properly wire up get_user_pages_fast() on 32-bit

While we did add support for _PAGE_SPECIAL on some 32-bit platforms,
we never actually built get_user_pages_fast() on them. This fixes
it which requires a little bit of ifdef'ing around.

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

1 files changed, 15 insertions, 1 deletions

diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
index 28a114db3ba0..bc400c78c97f 100644
--- a/arch/powerpc/mm/gup.c
+++ b/arch/powerpc/mm/gup.c
@@ -14,6 +14,8 @@
 #include <linux/rwsem.h>
 #include <asm/pgtable.h>
 
+#ifdef __HAVE_ARCH_PTE_SPECIAL
+
 /*
  * The performance critical leaf functions are made noinline otherwise gcc
  * inlines everything into a single function which results in too much
@@ -151,8 +153,11 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
         unsigned long addr, len, end;
         unsigned long next;
         pgd_t *pgdp;
-        int psize, nr = 0;
+        int nr = 0;
+#ifdef CONFIG_PPC64
         unsigned int shift;
+        int psize;
+#endif
 
         pr_debug("%s(%lx,%x,%s)\n", __func__, start, nr_pages, write ? "write" : "read");
 
@@ -205,8 +210,13 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
          */
         local_irq_disable();
 
+#ifdef CONFIG_PPC64
+        /* Those bits are related to hugetlbfs implementation and only exist
+         * on 64-bit for now
+         */
         psize = get_slice_psize(mm, addr);
         shift = mmu_psize_defs[psize].shift;
+#endif /* CONFIG_PPC64 */
 
 #ifdef CONFIG_HUGETLB_PAGE
         if (unlikely(mmu_huge_psizes[psize])) {
@@ -236,7 +246,9 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
                 do {
                         pgd_t pgd = *pgdp;
 
+#ifdef CONFIG_PPC64
                         VM_BUG_ON(shift != mmu_psize_defs[get_slice_psize(mm, addr)].shift);
+#endif
                         pr_debug("  %016lx: normal pgd %p\n", addr,
                                  (void *)pgd_val(pgd));
                         next = pgd_addr_end(addr, end);
@@ -279,3 +291,5 @@ slow_irqon:
                 return ret;
         }
 }
+
+#endif /* __HAVE_ARCH_PTE_SPECIAL */