5 files changed, 25 insertions, 6 deletions

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index b2f3dbca6952..f15dfb92dec0 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -329,12 +329,14 @@ static void __init htab_init_page_sizes(void)
          */
         if (mmu_psize_defs[MMU_PAGE_16M].shift)
                 mmu_huge_psize = MMU_PAGE_16M;
+        /* With 4k/4level pagetables, we can't (for now) cope with a
+         * huge page size < PMD_SIZE */
         else if (mmu_psize_defs[MMU_PAGE_1M].shift)
                 mmu_huge_psize = MMU_PAGE_1M;
 
         /* Calculate HPAGE_SHIFT and sanity check it */
-        if (mmu_psize_defs[mmu_huge_psize].shift > 16 &&
-            mmu_psize_defs[mmu_huge_psize].shift < 28)
+        if (mmu_psize_defs[mmu_huge_psize].shift > MIN_HUGEPTE_SHIFT &&
+            mmu_psize_defs[mmu_huge_psize].shift < SID_SHIFT)
                 HPAGE_SHIFT = mmu_psize_defs[mmu_huge_psize].shift;
         else
                 HPAGE_SHIFT = 0; /* No huge pages dude ! */
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 0073a04047e4..426c269e552e 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -212,6 +212,12 @@ static int prepare_high_area_for_htlb(struct mm_struct *mm, unsigned long area)
 
         BUG_ON(area >= NUM_HIGH_AREAS);
 
+        /* Hack, so that each addresses is controlled by exactly one
+         * of the high or low area bitmaps, the first high area starts
+         * at 4GB, not 0 */
+        if (start == 0)
+                start = 0x100000000UL;
+
         /* Check no VMAs are in the region */
         vma = find_vma(mm, start);
         if (vma && (vma->vm_start < end))
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 3e18241b6f35..950ffc5848c7 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -80,12 +80,17 @@ _GLOBAL(slb_miss_kernel_load_virtual)
 BEGIN_FTR_SECTION
         b       1f
 END_FTR_SECTION_IFCLR(CPU_FTR_16M_PAGE)
+        cmpldi  r10,16
+
+        lhz     r9,PACALOWHTLBAREAS(r13)
+        mr      r11,r10
+        blt     5f
+
         lhz     r9,PACAHIGHHTLBAREAS(r13)
         srdi    r11,r10,(HTLB_AREA_SHIFT-SID_SHIFT)
-        srd     r9,r9,r11
-        lhz     r11,PACALOWHTLBAREAS(r13)
-        srd     r11,r11,r10
-        or.     r9,r9,r11
+
+5:      srd     r9,r9,r11
+        andi.   r9,r9,1
         beq     1f
 _GLOBAL(slb_miss_user_load_huge)
         li      r11,0
diff --git a/include/asm-ppc64/pgtable-4k.h b/include/asm-ppc64/pgtable-4k.h
index c883a2748558..e9590c06ad92 100644
--- a/include/asm-ppc64/pgtable-4k.h
+++ b/include/asm-ppc64/pgtable-4k.h
@@ -23,6 +23,9 @@
 #define PMD_SIZE        (1UL << PMD_SHIFT)
 #define PMD_MASK        (~(PMD_SIZE-1))
 
+/* With 4k base page size, hugepage PTEs go at the PMD level */
+#define MIN_HUGEPTE_SHIFT       PMD_SHIFT
+
 /* PUD_SHIFT determines what a third-level page table entry can map */
 #define PUD_SHIFT       (PMD_SHIFT + PMD_INDEX_SIZE)
 #define PUD_SIZE        (1UL << PUD_SHIFT)
diff --git a/include/asm-ppc64/pgtable-64k.h b/include/asm-ppc64/pgtable-64k.h
index c5f437c86b3c..154f1840ece4 100644
--- a/include/asm-ppc64/pgtable-64k.h
+++ b/include/asm-ppc64/pgtable-64k.h
@@ -14,6 +14,9 @@
 #define PTRS_PER_PMD    (1 << PMD_INDEX_SIZE)
 #define PTRS_PER_PGD    (1 << PGD_INDEX_SIZE)
 
+/* With 4k base page size, hugepage PTEs go at the PMD level */
+#define MIN_HUGEPTE_SHIFT       PAGE_SHIFT
+
 /* PMD_SHIFT determines what a second-level page table entry can map */
 #define PMD_SHIFT       (PAGE_SHIFT + PTE_INDEX_SIZE)
 #define PMD_SIZE        (1UL << PMD_SHIFT)