diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 808d2ef..5226f70 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -352,6 +352,11 @@
 	def_bool y
 	depends on PPC_STD_MMU && PPC32
 
+config PPC_MM_SLICES
+	bool
+	default y if HUGETLB_PAGE
+	default n
+
 config VIRT_CPU_ACCOUNTING
 	bool "Deterministic task and CPU time accounting"
 	depends on PPC64
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 8f48560..d6803fb 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -122,12 +122,18 @@
 	DEFINE(PACASLBCACHE, offsetof(struct paca_struct, slb_cache));
 	DEFINE(PACASLBCACHEPTR, offsetof(struct paca_struct, slb_cache_ptr));
 	DEFINE(PACACONTEXTID, offsetof(struct paca_struct, context.id));
-	DEFINE(PACACONTEXTSLLP, offsetof(struct paca_struct, context.sllp));
 	DEFINE(PACAVMALLOCSLLP, offsetof(struct paca_struct, vmalloc_sllp));
-#ifdef CONFIG_HUGETLB_PAGE
-	DEFINE(PACALOWHTLBAREAS, offsetof(struct paca_struct, context.low_htlb_areas));
-	DEFINE(PACAHIGHHTLBAREAS, offsetof(struct paca_struct, context.high_htlb_areas));
-#endif /* CONFIG_HUGETLB_PAGE */
+#ifdef CONFIG_PPC_MM_SLICES
+	DEFINE(PACALOWSLICESPSIZE, offsetof(struct paca_struct,
+					    context.low_slices_psize));
+	DEFINE(PACAHIGHSLICEPSIZE, offsetof(struct paca_struct,
+					    context.high_slices_psize));
+	DEFINE(MMUPSIZEDEFSIZE, sizeof(struct mmu_psize_def));
+	DEFINE(MMUPSIZESLLP, offsetof(struct mmu_psize_def, sllp));
+#else
+	DEFINE(PACACONTEXTSLLP, offsetof(struct paca_struct, context.sllp));
+
+#endif /* CONFIG_PPC_MM_SLICES */
 	DEFINE(PACA_EXGEN, offsetof(struct paca_struct, exgen));
 	DEFINE(PACA_EXMC, offsetof(struct paca_struct, exmc));
 	DEFINE(PACA_EXSLB, offsetof(struct paca_struct, exslb));
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 38a81967..4f839c6 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -18,4 +18,5 @@
 obj-$(CONFIG_44x)		+= 44x_mmu.o
 obj-$(CONFIG_FSL_BOOKE)		+= fsl_booke_mmu.o
 obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o
+obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 71092c2..5610ffb 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -51,6 +51,7 @@
 #include <asm/cputable.h>
 #include <asm/abs_addr.h>
 #include <asm/sections.h>
+#include <asm/spu.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) udbg_printf(fmt)
@@ -601,8 +602,13 @@
 {
 	if (mm->context.user_psize == MMU_PAGE_4K)
 		return;
+#ifdef CONFIG_PPC_MM_SLICES
+	slice_set_user_psize(mm, MMU_PAGE_4K);
+#else /* CONFIG_PPC_MM_SLICES */
 	mm->context.user_psize = MMU_PAGE_4K;
 	mm->context.sllp = SLB_VSID_USER | mmu_psize_defs[MMU_PAGE_4K].sllp;
+#endif /* CONFIG_PPC_MM_SLICES */
+
 #ifdef CONFIG_SPE_BASE
 	spu_flush_all_slbs(mm);
 #endif
@@ -670,11 +676,14 @@
 	if (user_region && cpus_equal(mm->cpu_vm_mask, tmp))
 		local = 1;
 
+#ifdef CONFIG_HUGETLB_PAGE
 	/* Handle hugepage regions */
-	if (unlikely(in_hugepage_area(mm->context, ea))) {
+	if (HPAGE_SHIFT &&
+	    unlikely(get_slice_psize(mm, ea) == mmu_huge_psize)) {
 		DBG_LOW(" -> huge page !\n");
 		return hash_huge_page(mm, access, ea, vsid, local, trap);
 	}
+#endif /* CONFIG_HUGETLB_PAGE */
 
 	/* Get PTE and page size from page tables */
 	ptep = find_linux_pte(pgdir, ea);
@@ -770,10 +779,13 @@
 	unsigned long flags;
 	int local = 0;
 
-	/* We don't want huge pages prefaulted for now
-	 */
-	if (unlikely(in_hugepage_area(mm->context, ea)))
+	BUG_ON(REGION_ID(ea) != USER_REGION_ID);
+
+#ifdef CONFIG_PPC_MM_SLICES
+	/* We only prefault standard pages for now */
+	if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize));
 		return;
+#endif
 
 	DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
 		" trap=%lx\n", mm, mm->pgd, ea, access, trap);
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index fb95926..92a1b16 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -91,7 +91,7 @@
 	pgd_t *pg;
 	pud_t *pu;
 
-	BUG_ON(! in_hugepage_area(mm->context, addr));
+	BUG_ON(get_slice_psize(mm, addr) != mmu_huge_psize);
 
 	addr &= HPAGE_MASK;
 
@@ -119,7 +119,7 @@
 	pud_t *pu;
 	hugepd_t *hpdp = NULL;
 
-	BUG_ON(! in_hugepage_area(mm->context, addr));
+	BUG_ON(get_slice_psize(mm, addr) != mmu_huge_psize);
 
 	addr &= HPAGE_MASK;
 
@@ -302,7 +302,7 @@
 	start = addr;
 	pgd = pgd_offset((*tlb)->mm, addr);
 	do {
-		BUG_ON(! in_hugepage_area((*tlb)->mm->context, addr));
+		BUG_ON(get_slice_psize((*tlb)->mm, addr) != mmu_huge_psize);
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
@@ -331,203 +331,13 @@
 	return __pte(old);
 }
 
-struct slb_flush_info {
-	struct mm_struct *mm;
-	u16 newareas;
-};
-
-static void flush_low_segments(void *parm)
-{
-	struct slb_flush_info *fi = parm;
-	unsigned long i;
-
-	BUILD_BUG_ON((sizeof(fi->newareas)*8) != NUM_LOW_AREAS);
-
-	if (current->active_mm != fi->mm)
-		return;
-
-	/* Only need to do anything if this CPU is working in the same
-	 * mm as the one which has changed */
-
-	/* update the paca copy of the context struct */
-	get_paca()->context = current->active_mm->context;
-
-	asm volatile("isync" : : : "memory");
-	for (i = 0; i < NUM_LOW_AREAS; i++) {
-		if (! (fi->newareas & (1U << i)))
-			continue;
-		asm volatile("slbie %0"
-			     : : "r" ((i << SID_SHIFT) | SLBIE_C));
-	}
-	asm volatile("isync" : : : "memory");
-}
-
-static void flush_high_segments(void *parm)
-{
-	struct slb_flush_info *fi = parm;
-	unsigned long i, j;
-
-
-	BUILD_BUG_ON((sizeof(fi->newareas)*8) != NUM_HIGH_AREAS);
-
-	if (current->active_mm != fi->mm)
-		return;
-
-	/* Only need to do anything if this CPU is working in the same
-	 * mm as the one which has changed */
-
-	/* update the paca copy of the context struct */
-	get_paca()->context = current->active_mm->context;
-
-	asm volatile("isync" : : : "memory");
-	for (i = 0; i < NUM_HIGH_AREAS; i++) {
-		if (! (fi->newareas & (1U << i)))
-			continue;
-		for (j = 0; j < (1UL << (HTLB_AREA_SHIFT-SID_SHIFT)); j++)
-			asm volatile("slbie %0"
-				     :: "r" (((i << HTLB_AREA_SHIFT)
-					      + (j << SID_SHIFT)) | SLBIE_C));
-	}
-	asm volatile("isync" : : : "memory");
-}
-
-static int prepare_low_area_for_htlb(struct mm_struct *mm, unsigned long area)
-{
-	unsigned long start = area << SID_SHIFT;
-	unsigned long end = (area+1) << SID_SHIFT;
-	struct vm_area_struct *vma;
-
-	BUG_ON(area >= NUM_LOW_AREAS);
-
-	/* Check no VMAs are in the region */
-	vma = find_vma(mm, start);
-	if (vma && (vma->vm_start < end))
-		return -EBUSY;
-
-	return 0;
-}
-
-static int prepare_high_area_for_htlb(struct mm_struct *mm, unsigned long area)
-{
-	unsigned long start = area << HTLB_AREA_SHIFT;
-	unsigned long end = (area+1) << HTLB_AREA_SHIFT;
-	struct vm_area_struct *vma;
-
-	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))
-		return -EBUSY;
-
-	return 0;
-}
-
-static int open_low_hpage_areas(struct mm_struct *mm, u16 newareas)
-{
-	unsigned long i;
-	struct slb_flush_info fi;
-
-	BUILD_BUG_ON((sizeof(newareas)*8) != NUM_LOW_AREAS);
-	BUILD_BUG_ON((sizeof(mm->context.low_htlb_areas)*8) != NUM_LOW_AREAS);
-
-	newareas &= ~(mm->context.low_htlb_areas);
-	if (! newareas)
-		return 0; /* The segments we want are already open */
-
-	for (i = 0; i < NUM_LOW_AREAS; i++)
-		if ((1 << i) & newareas)
-			if (prepare_low_area_for_htlb(mm, i) != 0)
-				return -EBUSY;
-
-	mm->context.low_htlb_areas |= newareas;
-
-	/* the context change must make it to memory before the flush,
-	 * so that further SLB misses do the right thing. */
-	mb();
-
-	fi.mm = mm;
-	fi.newareas = newareas;
-	on_each_cpu(flush_low_segments, &fi, 0, 1);
-
-	return 0;
-}
-
-static int open_high_hpage_areas(struct mm_struct *mm, u16 newareas)
-{
-	struct slb_flush_info fi;
-	unsigned long i;
-
-	BUILD_BUG_ON((sizeof(newareas)*8) != NUM_HIGH_AREAS);
-	BUILD_BUG_ON((sizeof(mm->context.high_htlb_areas)*8)
-		     != NUM_HIGH_AREAS);
-
-	newareas &= ~(mm->context.high_htlb_areas);
-	if (! newareas)
-		return 0; /* The areas we want are already open */
-
-	for (i = 0; i < NUM_HIGH_AREAS; i++)
-		if ((1 << i) & newareas)
-			if (prepare_high_area_for_htlb(mm, i) != 0)
-				return -EBUSY;
-
-	mm->context.high_htlb_areas |= newareas;
-
-	/* the context change must make it to memory before the flush,
-	 * so that further SLB misses do the right thing. */
-	mb();
-
-	fi.mm = mm;
-	fi.newareas = newareas;
-	on_each_cpu(flush_high_segments, &fi, 0, 1);
-
-	return 0;
-}
-
-int prepare_hugepage_range(unsigned long addr, unsigned long len, pgoff_t pgoff)
-{
-	int err = 0;
-
-	if (pgoff & (~HPAGE_MASK >> PAGE_SHIFT))
-		return -EINVAL;
-	if (len & ~HPAGE_MASK)
-		return -EINVAL;
-	if (addr & ~HPAGE_MASK)
-		return -EINVAL;
-
-	if (addr < 0x100000000UL)
-		err = open_low_hpage_areas(current->mm,
-					  LOW_ESID_MASK(addr, len));
-	if ((addr + len) > 0x100000000UL)
-		err = open_high_hpage_areas(current->mm,
-					    HTLB_AREA_MASK(addr, len));
-#ifdef CONFIG_SPE_BASE
-	spu_flush_all_slbs(current->mm);
-#endif
-	if (err) {
-		printk(KERN_DEBUG "prepare_hugepage_range(%lx, %lx)"
-		       " failed (lowmask: 0x%04hx, highmask: 0x%04hx)\n",
-		       addr, len,
-		       LOW_ESID_MASK(addr, len), HTLB_AREA_MASK(addr, len));
-		return err;
-	}
-
-	return 0;
-}
-
 struct page *
 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
 {
 	pte_t *ptep;
 	struct page *page;
 
-	if (! in_hugepage_area(mm->context, address))
+	if (get_slice_psize(mm, address) != mmu_huge_psize)
 		return ERR_PTR(-EINVAL);
 
 	ptep = huge_pte_offset(mm, address);
@@ -551,359 +361,13 @@
 	return NULL;
 }
 
-/* Because we have an exclusive hugepage region which lies within the
- * normal user address space, we have to take special measures to make
- * non-huge mmap()s evade the hugepage reserved regions. */
-unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
-				     unsigned long len, unsigned long pgoff,
-				     unsigned long flags)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma;
-	unsigned long start_addr;
-
-	if (len > TASK_SIZE)
-		return -ENOMEM;
-
-	/* handle fixed mapping: prevent overlap with huge pages */
-	if (flags & MAP_FIXED) {
-		if (is_hugepage_only_range(mm, addr, len))
-			return -EINVAL;
-		return addr;
-	}
-
-	if (addr) {
-		addr = PAGE_ALIGN(addr);
-		vma = find_vma(mm, addr);
-		if (((TASK_SIZE - len) >= addr)
-		    && (!vma || (addr+len) <= vma->vm_start)
-		    && !is_hugepage_only_range(mm, addr,len))
-			return addr;
-	}
-	if (len > mm->cached_hole_size) {
-	        start_addr = addr = mm->free_area_cache;
-	} else {
-	        start_addr = addr = TASK_UNMAPPED_BASE;
-	        mm->cached_hole_size = 0;
-	}
-
-full_search:
-	vma = find_vma(mm, addr);
-	while (TASK_SIZE - len >= addr) {
-		BUG_ON(vma && (addr >= vma->vm_end));
-
-		if (touches_hugepage_low_range(mm, addr, len)) {
-			addr = ALIGN(addr+1, 1<<SID_SHIFT);
-			vma = find_vma(mm, addr);
-			continue;
-		}
-		if (touches_hugepage_high_range(mm, addr, len)) {
-			addr = ALIGN(addr+1, 1UL<<HTLB_AREA_SHIFT);
-			vma = find_vma(mm, addr);
-			continue;
-		}
-		if (!vma || addr + len <= vma->vm_start) {
-			/*
-			 * Remember the place where we stopped the search:
-			 */
-			mm->free_area_cache = addr + len;
-			return addr;
-		}
-		if (addr + mm->cached_hole_size < vma->vm_start)
-		        mm->cached_hole_size = vma->vm_start - addr;
-		addr = vma->vm_end;
-		vma = vma->vm_next;
-	}
-
-	/* Make sure we didn't miss any holes */
-	if (start_addr != TASK_UNMAPPED_BASE) {
-		start_addr = addr = TASK_UNMAPPED_BASE;
-		mm->cached_hole_size = 0;
-		goto full_search;
-	}
-	return -ENOMEM;
-}
-
-/*
- * This mmap-allocator allocates new areas top-down from below the
- * stack's low limit (the base):
- *
- * Because we have an exclusive hugepage region which lies within the
- * normal user address space, we have to take special measures to make
- * non-huge mmap()s evade the hugepage reserved regions.
- */
-unsigned long
-arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
-			  const unsigned long len, const unsigned long pgoff,
-			  const unsigned long flags)
-{
-	struct vm_area_struct *vma, *prev_vma;
-	struct mm_struct *mm = current->mm;
-	unsigned long base = mm->mmap_base, addr = addr0;
-	unsigned long largest_hole = mm->cached_hole_size;
-	int first_time = 1;
-
-	/* requested length too big for entire address space */
-	if (len > TASK_SIZE)
-		return -ENOMEM;
-
-	/* handle fixed mapping: prevent overlap with huge pages */
-	if (flags & MAP_FIXED) {
-		if (is_hugepage_only_range(mm, addr, len))
-			return -EINVAL;
-		return addr;
-	}
-
-	/* dont allow allocations above current base */
-	if (mm->free_area_cache > base)
-		mm->free_area_cache = base;
-
-	/* requesting a specific address */
-	if (addr) {
-		addr = PAGE_ALIGN(addr);
-		vma = find_vma(mm, addr);
-		if (TASK_SIZE - len >= addr &&
-				(!vma || addr + len <= vma->vm_start)
-				&& !is_hugepage_only_range(mm, addr,len))
-			return addr;
-	}
-
-	if (len <= largest_hole) {
-	        largest_hole = 0;
-		mm->free_area_cache = base;
-	}
-try_again:
-	/* make sure it can fit in the remaining address space */
-	if (mm->free_area_cache < len)
-		goto fail;
-
-	/* either no address requested or cant fit in requested address hole */
-	addr = (mm->free_area_cache - len) & PAGE_MASK;
-	do {
-hugepage_recheck:
-		if (touches_hugepage_low_range(mm, addr, len)) {
-			addr = (addr & ((~0) << SID_SHIFT)) - len;
-			goto hugepage_recheck;
-		} else if (touches_hugepage_high_range(mm, addr, len)) {
-			addr = (addr & ((~0UL) << HTLB_AREA_SHIFT)) - len;
-			goto hugepage_recheck;
-		}
-
-		/*
-		 * Lookup failure means no vma is above this address,
-		 * i.e. return with success:
-		 */
- 	 	if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
-			return addr;
-
-		/*
-		 * new region fits between prev_vma->vm_end and
-		 * vma->vm_start, use it:
-		 */
-		if (addr+len <= vma->vm_start &&
-		          (!prev_vma || (addr >= prev_vma->vm_end))) {
-			/* remember the address as a hint for next time */
-		        mm->cached_hole_size = largest_hole;
-		        return (mm->free_area_cache = addr);
-		} else {
-			/* pull free_area_cache down to the first hole */
-		        if (mm->free_area_cache == vma->vm_end) {
-				mm->free_area_cache = vma->vm_start;
-				mm->cached_hole_size = largest_hole;
-			}
-		}
-
-		/* remember the largest hole we saw so far */
-		if (addr + largest_hole < vma->vm_start)
-		        largest_hole = vma->vm_start - addr;
-
-		/* try just below the current vma->vm_start */
-		addr = vma->vm_start-len;
-	} while (len <= vma->vm_start);
-
-fail:
-	/*
-	 * if hint left us with no space for the requested
-	 * mapping then try again:
-	 */
-	if (first_time) {
-		mm->free_area_cache = base;
-		largest_hole = 0;
-		first_time = 0;
-		goto try_again;
-	}
-	/*
-	 * A failed mmap() very likely causes application failure,
-	 * so fall back to the bottom-up function here. This scenario
-	 * can happen with large stack limits and large mmap()
-	 * allocations.
-	 */
-	mm->free_area_cache = TASK_UNMAPPED_BASE;
-	mm->cached_hole_size = ~0UL;
-	addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
-	/*
-	 * Restore the topdown base:
-	 */
-	mm->free_area_cache = base;
-	mm->cached_hole_size = ~0UL;
-
-	return addr;
-}
-
-static int htlb_check_hinted_area(unsigned long addr, unsigned long len)
-{
-	struct vm_area_struct *vma;
-
-	vma = find_vma(current->mm, addr);
-	if (TASK_SIZE - len >= addr &&
-	    (!vma || ((addr + len) <= vma->vm_start)))
-		return 0;
-
-	return -ENOMEM;
-}
-
-static unsigned long htlb_get_low_area(unsigned long len, u16 segmask)
-{
-	unsigned long addr = 0;
-	struct vm_area_struct *vma;
-
-	vma = find_vma(current->mm, addr);
-	while (addr + len <= 0x100000000UL) {
-		BUG_ON(vma && (addr >= vma->vm_end)); /* invariant */
-
-		if (! __within_hugepage_low_range(addr, len, segmask)) {
-			addr = ALIGN(addr+1, 1<<SID_SHIFT);
-			vma = find_vma(current->mm, addr);
-			continue;
-		}
-
-		if (!vma || (addr + len) <= vma->vm_start)
-			return addr;
-		addr = ALIGN(vma->vm_end, HPAGE_SIZE);
-		/* Depending on segmask this might not be a confirmed
-		 * hugepage region, so the ALIGN could have skipped
-		 * some VMAs */
-		vma = find_vma(current->mm, addr);
-	}
-
-	return -ENOMEM;
-}
-
-static unsigned long htlb_get_high_area(unsigned long len, u16 areamask)
-{
-	unsigned long addr = 0x100000000UL;
-	struct vm_area_struct *vma;
-
-	vma = find_vma(current->mm, addr);
-	while (addr + len <= TASK_SIZE_USER64) {
-		BUG_ON(vma && (addr >= vma->vm_end)); /* invariant */
-
-		if (! __within_hugepage_high_range(addr, len, areamask)) {
-			addr = ALIGN(addr+1, 1UL<<HTLB_AREA_SHIFT);
-			vma = find_vma(current->mm, addr);
-			continue;
-		}
-
-		if (!vma || (addr + len) <= vma->vm_start)
-			return addr;
-		addr = ALIGN(vma->vm_end, HPAGE_SIZE);
-		/* Depending on segmask this might not be a confirmed
-		 * hugepage region, so the ALIGN could have skipped
-		 * some VMAs */
-		vma = find_vma(current->mm, addr);
-	}
-
-	return -ENOMEM;
-}
 
 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 					unsigned long len, unsigned long pgoff,
 					unsigned long flags)
 {
-	int lastshift;
-	u16 areamask, curareas;
-
-	if (HPAGE_SHIFT == 0)
-		return -EINVAL;
-	if (len & ~HPAGE_MASK)
-		return -EINVAL;
-	if (len > TASK_SIZE)
-		return -ENOMEM;
-
-	if (!cpu_has_feature(CPU_FTR_16M_PAGE))
-		return -EINVAL;
-
-	/* Paranoia, caller should have dealt with this */
-	BUG_ON((addr + len)  < addr);
-
-	/* Handle MAP_FIXED */
-	if (flags & MAP_FIXED) {
-		if (prepare_hugepage_range(addr, len, pgoff))
-			return -EINVAL;
-		return addr;
-	}
-
-	if (test_thread_flag(TIF_32BIT)) {
-		curareas = current->mm->context.low_htlb_areas;
-
-		/* First see if we can use the hint address */
-		if (addr && (htlb_check_hinted_area(addr, len) == 0)) {
-			areamask = LOW_ESID_MASK(addr, len);
-			if (open_low_hpage_areas(current->mm, areamask) == 0)
-				return addr;
-		}
-
-		/* Next see if we can map in the existing low areas */
-		addr = htlb_get_low_area(len, curareas);
-		if (addr != -ENOMEM)
-			return addr;
-
-		/* Finally go looking for areas to open */
-		lastshift = 0;
-		for (areamask = LOW_ESID_MASK(0x100000000UL-len, len);
-		     ! lastshift; areamask >>=1) {
-			if (areamask & 1)
-				lastshift = 1;
-
-			addr = htlb_get_low_area(len, curareas | areamask);
-			if ((addr != -ENOMEM)
-			    && open_low_hpage_areas(current->mm, areamask) == 0)
-				return addr;
-		}
-	} else {
-		curareas = current->mm->context.high_htlb_areas;
-
-		/* First see if we can use the hint address */
-		/* We discourage 64-bit processes from doing hugepage
-		 * mappings below 4GB (must use MAP_FIXED) */
-		if ((addr >= 0x100000000UL)
-		    && (htlb_check_hinted_area(addr, len) == 0)) {
-			areamask = HTLB_AREA_MASK(addr, len);
-			if (open_high_hpage_areas(current->mm, areamask) == 0)
-				return addr;
-		}
-
-		/* Next see if we can map in the existing high areas */
-		addr = htlb_get_high_area(len, curareas);
-		if (addr != -ENOMEM)
-			return addr;
-
-		/* Finally go looking for areas to open */
-		lastshift = 0;
-		for (areamask = HTLB_AREA_MASK(TASK_SIZE_USER64-len, len);
-		     ! lastshift; areamask >>=1) {
-			if (areamask & 1)
-				lastshift = 1;
-
-			addr = htlb_get_high_area(len, curareas | areamask);
-			if ((addr != -ENOMEM)
-			    && open_high_hpage_areas(current->mm, areamask) == 0)
-				return addr;
-		}
-	}
-	printk(KERN_DEBUG "hugetlb_get_unmapped_area() unable to open"
-	       " enough areas\n");
-	return -ENOMEM;
+	return slice_get_unmapped_area(addr, len, flags,
+				       mmu_huge_psize, 1, 0);
 }
 
 /*
diff --git a/arch/powerpc/mm/mmu_context_64.c b/arch/powerpc/mm/mmu_context_64.c
index 90a06ac..7a78cdc 100644
--- a/arch/powerpc/mm/mmu_context_64.c
+++ b/arch/powerpc/mm/mmu_context_64.c
@@ -28,6 +28,7 @@
 {
 	int index;
 	int err;
+	int new_context = (mm->context.id == 0);
 
 again:
 	if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL))
@@ -50,9 +51,18 @@
 	}
 
 	mm->context.id = index;
+#ifdef CONFIG_PPC_MM_SLICES
+	/* The old code would re-promote on fork, we don't do that
+	 * when using slices as it could cause problem promoting slices
+	 * that have been forced down to 4K
+	 */
+	if (new_context)
+		slice_set_user_psize(mm, mmu_virtual_psize);
+#else
 	mm->context.user_psize = mmu_virtual_psize;
 	mm->context.sllp = SLB_VSID_USER |
 		mmu_psize_defs[mmu_virtual_psize].sllp;
+#endif
 
 	return 0;
 }
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 224e960..304375a7 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -198,12 +198,6 @@
 	static int slb_encoding_inited;
 	extern unsigned int *slb_miss_kernel_load_linear;
 	extern unsigned int *slb_miss_kernel_load_io;
-#ifdef CONFIG_HUGETLB_PAGE
-	extern unsigned int *slb_miss_user_load_huge;
-	unsigned long huge_llp;
-
-	huge_llp = mmu_psize_defs[mmu_huge_psize].sllp;
-#endif
 
 	/* Prepare our SLB miss handler based on our page size */
 	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
@@ -220,11 +214,6 @@
 
 		DBG("SLB: linear  LLP = %04x\n", linear_llp);
 		DBG("SLB: io      LLP = %04x\n", io_llp);
-#ifdef CONFIG_HUGETLB_PAGE
-		patch_slb_encoding(slb_miss_user_load_huge,
-				   SLB_VSID_USER | huge_llp);
-		DBG("SLB: huge    LLP = %04x\n", huge_llp);
-#endif
 	}
 
 	get_paca()->stab_rr = SLB_NUM_BOLTED;
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index b10e470..cd1a93d 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -82,31 +82,45 @@
 	srdi.	r9,r10,USER_ESID_BITS
 	bne-	8f			/* invalid ea bits set */
 
-	/* Figure out if the segment contains huge pages */
-#ifdef CONFIG_HUGETLB_PAGE
-BEGIN_FTR_SECTION
-	b	1f
-END_FTR_SECTION_IFCLR(CPU_FTR_16M_PAGE)
+
+	/* when using slices, we extract the psize off the slice bitmaps
+	 * and then we need to get the sllp encoding off the mmu_psize_defs
+	 * array.
+	 *
+	 * XXX This is a bit inefficient especially for the normal case,
+	 * so we should try to implement a fast path for the standard page
+	 * size using the old sllp value so we avoid the array. We cannot
+	 * really do dynamic patching unfortunately as processes might flip
+	 * between 4k and 64k standard page size
+	 */
+#ifdef CONFIG_PPC_MM_SLICES
 	cmpldi	r10,16
 
-	lhz	r9,PACALOWHTLBAREAS(r13)
-	mr	r11,r10
+	/* Get the slice index * 4 in r11 and matching slice size mask in r9 */
+	ld	r9,PACALOWSLICESPSIZE(r13)
+	sldi	r11,r10,2
 	blt	5f
+	ld	r9,PACAHIGHSLICEPSIZE(r13)
+	srdi	r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT - 2)
+	andi.	r11,r11,0x3c
 
-	lhz	r9,PACAHIGHHTLBAREAS(r13)
-	srdi	r11,r10,(HTLB_AREA_SHIFT-SID_SHIFT)
+5:	/* Extract the psize and multiply to get an array offset */
+	srd	r9,r9,r11
+	andi.	r9,r9,0xf
+	mulli	r9,r9,MMUPSIZEDEFSIZE
 
-5:	srd	r9,r9,r11
-	andi.	r9,r9,1
-	beq	1f
-_GLOBAL(slb_miss_user_load_huge)
-	li	r11,0
-	b	2f
-1:
-#endif /* CONFIG_HUGETLB_PAGE */
-
+	/* Now get to the array and obtain the sllp
+	 */
+	ld	r11,PACATOC(r13)
+	ld	r11,mmu_psize_defs@got(r11)
+	add	r11,r11,r9
+	ld	r11,MMUPSIZESLLP(r11)
+	ori	r11,r11,SLB_VSID_USER
+#else
+	/* paca context sllp already contains the SLB_VSID_USER bits */
 	lhz	r11,PACACONTEXTSLLP(r13)
-2:
+#endif /* CONFIG_PPC_MM_SLICES */
+
 	ld	r9,PACACONTEXTID(r13)
 	rldimi	r10,r9,USER_ESID_BITS,0
 	b	slb_finish_load
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
new file mode 100644
index 0000000..f833dba
--- /dev/null
+++ b/arch/powerpc/mm/slice.c
@@ -0,0 +1,633 @@
+/*
+ * address space "slices" (meta-segments) support
+ *
+ * Copyright (C) 2007 Benjamin Herrenschmidt, IBM Corporation.
+ *
+ * Based on hugetlb implementation
+ *
+ * Copyright (C) 2003 David Gibson, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <asm/mman.h>
+#include <asm/mmu.h>
+#include <asm/spu.h>
+
+static spinlock_t slice_convert_lock = SPIN_LOCK_UNLOCKED;
+
+
+#ifdef DEBUG
+int _slice_debug = 1;
+
+static void slice_print_mask(const char *label, struct slice_mask mask)
+{
+	char	*p, buf[16 + 3 + 16 + 1];
+	int	i;
+
+	if (!_slice_debug)
+		return;
+	p = buf;
+	for (i = 0; i < SLICE_NUM_LOW; i++)
+		*(p++) = (mask.low_slices & (1 << i)) ? '1' : '0';
+	*(p++) = ' ';
+	*(p++) = '-';
+	*(p++) = ' ';
+	for (i = 0; i < SLICE_NUM_HIGH; i++)
+		*(p++) = (mask.high_slices & (1 << i)) ? '1' : '0';
+	*(p++) = 0;
+
+	printk(KERN_DEBUG "%s:%s\n", label, buf);
+}
+
+#define slice_dbg(fmt...) do { if (_slice_debug) pr_debug(fmt); } while(0)
+
+#else
+
+static void slice_print_mask(const char *label, struct slice_mask mask) {}
+#define slice_dbg(fmt...)
+
+#endif
+
+static struct slice_mask slice_range_to_mask(unsigned long start,
+					     unsigned long len)
+{
+	unsigned long end = start + len - 1;
+	struct slice_mask ret = { 0, 0 };
+
+	if (start < SLICE_LOW_TOP) {
+		unsigned long mend = min(end, SLICE_LOW_TOP);
+		unsigned long mstart = min(start, SLICE_LOW_TOP);
+
+		ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
+			- (1u << GET_LOW_SLICE_INDEX(mstart));
+	}
+
+	if ((start + len) > SLICE_LOW_TOP)
+		ret.high_slices = (1u << (GET_HIGH_SLICE_INDEX(end) + 1))
+			- (1u << GET_HIGH_SLICE_INDEX(start));
+
+	return ret;
+}
+
+static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
+			      unsigned long len)
+{
+	struct vm_area_struct *vma;
+
+	if ((mm->task_size - len) < addr)
+		return 0;
+	vma = find_vma(mm, addr);
+	return (!vma || (addr + len) <= vma->vm_start);
+}
+
+static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
+{
+	return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT,
+				   1ul << SLICE_LOW_SHIFT);
+}
+
+static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
+{
+	unsigned long start = slice << SLICE_HIGH_SHIFT;
+	unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
+
+	/* 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 = SLICE_LOW_TOP;
+
+	return !slice_area_is_free(mm, start, end - start);
+}
+
+static struct slice_mask slice_mask_for_free(struct mm_struct *mm)
+{
+	struct slice_mask ret = { 0, 0 };
+	unsigned long i;
+
+	for (i = 0; i < SLICE_NUM_LOW; i++)
+		if (!slice_low_has_vma(mm, i))
+			ret.low_slices |= 1u << i;
+
+	if (mm->task_size <= SLICE_LOW_TOP)
+		return ret;
+
+	for (i = 0; i < SLICE_NUM_HIGH; i++)
+		if (!slice_high_has_vma(mm, i))
+			ret.high_slices |= 1u << i;
+
+	return ret;
+}
+
+static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
+{
+	struct slice_mask ret = { 0, 0 };
+	unsigned long i;
+	u64 psizes;
+
+	psizes = mm->context.low_slices_psize;
+	for (i = 0; i < SLICE_NUM_LOW; i++)
+		if (((psizes >> (i * 4)) & 0xf) == psize)
+			ret.low_slices |= 1u << i;
+
+	psizes = mm->context.high_slices_psize;
+	for (i = 0; i < SLICE_NUM_HIGH; i++)
+		if (((psizes >> (i * 4)) & 0xf) == psize)
+			ret.high_slices |= 1u << i;
+
+	return ret;
+}
+
+static int slice_check_fit(struct slice_mask mask, struct slice_mask available)
+{
+	return (mask.low_slices & available.low_slices) == mask.low_slices &&
+		(mask.high_slices & available.high_slices) == mask.high_slices;
+}
+
+static void slice_flush_segments(void *parm)
+{
+	struct mm_struct *mm = parm;
+	unsigned long flags;
+
+	if (mm != current->active_mm)
+		return;
+
+	/* update the paca copy of the context struct */
+	get_paca()->context = current->active_mm->context;
+
+	local_irq_save(flags);
+	slb_flush_and_rebolt();
+	local_irq_restore(flags);
+}
+
+static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize)
+{
+	/* Write the new slice psize bits */
+	u64 lpsizes, hpsizes;
+	unsigned long i, flags;
+
+	slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
+	slice_print_mask(" mask", mask);
+
+	/* We need to use a spinlock here to protect against
+	 * concurrent 64k -> 4k demotion ...
+	 */
+	spin_lock_irqsave(&slice_convert_lock, flags);
+
+	lpsizes = mm->context.low_slices_psize;
+	for (i = 0; i < SLICE_NUM_LOW; i++)
+		if (mask.low_slices & (1u << i))
+			lpsizes = (lpsizes & ~(0xful << (i * 4))) |
+				(((unsigned long)psize) << (i * 4));
+
+	hpsizes = mm->context.high_slices_psize;
+	for (i = 0; i < SLICE_NUM_HIGH; i++)
+		if (mask.high_slices & (1u << i))
+			hpsizes = (hpsizes & ~(0xful << (i * 4))) |
+				(((unsigned long)psize) << (i * 4));
+
+	mm->context.low_slices_psize = lpsizes;
+	mm->context.high_slices_psize = hpsizes;
+
+	slice_dbg(" lsps=%lx, hsps=%lx\n",
+		  mm->context.low_slices_psize,
+		  mm->context.high_slices_psize);
+
+	spin_unlock_irqrestore(&slice_convert_lock, flags);
+	mb();
+
+	/* XXX this is sub-optimal but will do for now */
+	on_each_cpu(slice_flush_segments, mm, 0, 1);
+#ifdef CONFIG_SPU_BASE
+	spu_flush_all_slbs(mm);
+#endif
+}
+
+static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
+					      unsigned long len,
+					      struct slice_mask available,
+					      int psize, int use_cache)
+{
+	struct vm_area_struct *vma;
+	unsigned long start_addr, addr;
+	struct slice_mask mask;
+	int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
+
+	if (use_cache) {
+		if (len <= mm->cached_hole_size) {
+			start_addr = addr = TASK_UNMAPPED_BASE;
+			mm->cached_hole_size = 0;
+		} else
+			start_addr = addr = mm->free_area_cache;
+	} else
+		start_addr = addr = TASK_UNMAPPED_BASE;
+
+full_search:
+	for (;;) {
+		addr = _ALIGN_UP(addr, 1ul << pshift);
+		if ((TASK_SIZE - len) < addr)
+			break;
+		vma = find_vma(mm, addr);
+		BUG_ON(vma && (addr >= vma->vm_end));
+
+		mask = slice_range_to_mask(addr, len);
+		if (!slice_check_fit(mask, available)) {
+			if (addr < SLICE_LOW_TOP)
+				addr = _ALIGN_UP(addr + 1,  1ul << SLICE_LOW_SHIFT);
+			else
+				addr = _ALIGN_UP(addr + 1,  1ul << SLICE_HIGH_SHIFT);
+			continue;
+		}
+		if (!vma || addr + len <= vma->vm_start) {
+			/*
+			 * Remember the place where we stopped the search:
+			 */
+			if (use_cache)
+				mm->free_area_cache = addr + len;
+			return addr;
+		}
+		if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start)
+		        mm->cached_hole_size = vma->vm_start - addr;
+		addr = vma->vm_end;
+	}
+
+	/* Make sure we didn't miss any holes */
+	if (use_cache && start_addr != TASK_UNMAPPED_BASE) {
+		start_addr = addr = TASK_UNMAPPED_BASE;
+		mm->cached_hole_size = 0;
+		goto full_search;
+	}
+	return -ENOMEM;
+}
+
+static unsigned long slice_find_area_topdown(struct mm_struct *mm,
+					     unsigned long len,
+					     struct slice_mask available,
+					     int psize, int use_cache)
+{
+	struct vm_area_struct *vma;
+	unsigned long addr;
+	struct slice_mask mask;
+	int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
+
+	/* check if free_area_cache is useful for us */
+	if (use_cache) {
+		if (len <= mm->cached_hole_size) {
+			mm->cached_hole_size = 0;
+			mm->free_area_cache = mm->mmap_base;
+		}
+
+		/* either no address requested or can't fit in requested
+		 * address hole
+		 */
+		addr = mm->free_area_cache;
+
+		/* make sure it can fit in the remaining address space */
+		if (addr > len) {
+			addr = _ALIGN_DOWN(addr - len, 1ul << pshift);
+			mask = slice_range_to_mask(addr, len);
+			if (slice_check_fit(mask, available) &&
+			    slice_area_is_free(mm, addr, len))
+					/* remember the address as a hint for
+					 * next time
+					 */
+					return (mm->free_area_cache = addr);
+		}
+	}
+
+	addr = mm->mmap_base;
+	while (addr > len) {
+		/* Go down by chunk size */
+		addr = _ALIGN_DOWN(addr - len, 1ul << pshift);
+
+		/* Check for hit with different page size */
+		mask = slice_range_to_mask(addr, len);
+		if (!slice_check_fit(mask, available)) {
+			if (addr < SLICE_LOW_TOP)
+				addr = _ALIGN_DOWN(addr, 1ul << SLICE_LOW_SHIFT);
+			else if (addr < (1ul << SLICE_HIGH_SHIFT))
+				addr = SLICE_LOW_TOP;
+			else
+				addr = _ALIGN_DOWN(addr, 1ul << SLICE_HIGH_SHIFT);
+			continue;
+		}
+
+		/*
+		 * Lookup failure means no vma is above this address,
+		 * else if new region fits below vma->vm_start,
+		 * return with success:
+		 */
+		vma = find_vma(mm, addr);
+		if (!vma || (addr + len) <= vma->vm_start) {
+			/* remember the address as a hint for next time */
+			if (use_cache)
+				mm->free_area_cache = addr;
+			return addr;
+		}
+
+		/* remember the largest hole we saw so far */
+		if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start)
+		        mm->cached_hole_size = vma->vm_start - addr;
+
+		/* try just below the current vma->vm_start */
+		addr = vma->vm_start;
+	}
+
+	/*
+	 * A failed mmap() very likely causes application failure,
+	 * so fall back to the bottom-up function here. This scenario
+	 * can happen with large stack limits and large mmap()
+	 * allocations.
+	 */
+	addr = slice_find_area_bottomup(mm, len, available, psize, 0);
+
+	/*
+	 * Restore the topdown base:
+	 */
+	if (use_cache) {
+		mm->free_area_cache = mm->mmap_base;
+		mm->cached_hole_size = ~0UL;
+	}
+
+	return addr;
+}
+
+
+static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
+				     struct slice_mask mask, int psize,
+				     int topdown, int use_cache)
+{
+	if (topdown)
+		return slice_find_area_topdown(mm, len, mask, psize, use_cache);
+	else
+		return slice_find_area_bottomup(mm, len, mask, psize, use_cache);
+}
+
+unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
+				      unsigned long flags, unsigned int psize,
+				      int topdown, int use_cache)
+{
+	struct slice_mask mask;
+	struct slice_mask good_mask;
+	struct slice_mask potential_mask = {0,0} /* silence stupid warning */;
+	int pmask_set = 0;
+	int fixed = (flags & MAP_FIXED);
+	int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
+	struct mm_struct *mm = current->mm;
+
+	/* Sanity checks */
+	BUG_ON(mm->task_size == 0);
+
+	slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
+	slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d, use_cache=%d\n",
+		  addr, len, flags, topdown, use_cache);
+
+	if (len > mm->task_size)
+		return -ENOMEM;
+	if (fixed && (addr & ((1ul << pshift) - 1)))
+		return -EINVAL;
+	if (fixed && addr > (mm->task_size - len))
+		return -EINVAL;
+
+	/* If hint, make sure it matches our alignment restrictions */
+	if (!fixed && addr) {
+		addr = _ALIGN_UP(addr, 1ul << pshift);
+		slice_dbg(" aligned addr=%lx\n", addr);
+	}
+
+	/* First makeup a "good" mask of slices that have the right size
+	 * already
+	 */
+	good_mask = slice_mask_for_size(mm, psize);
+	slice_print_mask(" good_mask", good_mask);
+
+	/* First check hint if it's valid or if we have MAP_FIXED */
+	if ((addr != 0 || fixed) && (mm->task_size - len) >= addr) {
+
+		/* Don't bother with hint if it overlaps a VMA */
+		if (!fixed && !slice_area_is_free(mm, addr, len))
+			goto search;
+
+		/* Build a mask for the requested range */
+		mask = slice_range_to_mask(addr, len);
+		slice_print_mask(" mask", mask);
+
+		/* Check if we fit in the good mask. If we do, we just return,
+		 * nothing else to do
+		 */
+		if (slice_check_fit(mask, good_mask)) {
+			slice_dbg(" fits good !\n");
+			return addr;
+		}
+
+		/* We don't fit in the good mask, check what other slices are
+		 * empty and thus can be converted
+		 */
+		potential_mask = slice_mask_for_free(mm);
+		potential_mask.low_slices |= good_mask.low_slices;
+		potential_mask.high_slices |= good_mask.high_slices;
+		pmask_set = 1;
+		slice_print_mask(" potential", potential_mask);
+		if (slice_check_fit(mask, potential_mask)) {
+			slice_dbg(" fits potential !\n");
+			goto convert;
+		}
+	}
+
+	/* If we have MAP_FIXED and failed the above step, then error out */
+	if (fixed)
+		return -EBUSY;
+
+ search:
+	slice_dbg(" search...\n");
+
+	/* Now let's see if we can find something in the existing slices
+	 * for that size
+	 */
+	addr = slice_find_area(mm, len, good_mask, psize, topdown, use_cache);
+	if (addr != -ENOMEM) {
+		/* Found within the good mask, we don't have to setup,
+		 * we thus return directly
+		 */
+		slice_dbg(" found area at 0x%lx\n", addr);
+		return addr;
+	}
+
+	/* Won't fit, check what can be converted */
+	if (!pmask_set) {
+		potential_mask = slice_mask_for_free(mm);
+		potential_mask.low_slices |= good_mask.low_slices;
+		potential_mask.high_slices |= good_mask.high_slices;
+		pmask_set = 1;
+		slice_print_mask(" potential", potential_mask);
+	}
+
+	/* Now let's see if we can find something in the existing slices
+	 * for that size
+	 */
+	addr = slice_find_area(mm, len, potential_mask, psize, topdown,
+			       use_cache);
+	if (addr == -ENOMEM)
+		return -ENOMEM;
+
+	mask = slice_range_to_mask(addr, len);
+	slice_dbg(" found potential area at 0x%lx\n", addr);
+	slice_print_mask(" mask", mask);
+
+ convert:
+	slice_convert(mm, mask, psize);
+	return addr;
+
+}
+EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
+
+unsigned long arch_get_unmapped_area(struct file *filp,
+				     unsigned long addr,
+				     unsigned long len,
+				     unsigned long pgoff,
+				     unsigned long flags)
+{
+	return slice_get_unmapped_area(addr, len, flags,
+				       current->mm->context.user_psize,
+				       0, 1);
+}
+
+unsigned long arch_get_unmapped_area_topdown(struct file *filp,
+					     const unsigned long addr0,
+					     const unsigned long len,
+					     const unsigned long pgoff,
+					     const unsigned long flags)
+{
+	return slice_get_unmapped_area(addr0, len, flags,
+				       current->mm->context.user_psize,
+				       1, 1);
+}
+
+unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
+{
+	u64 psizes;
+	int index;
+
+	if (addr < SLICE_LOW_TOP) {
+		psizes = mm->context.low_slices_psize;
+		index = GET_LOW_SLICE_INDEX(addr);
+	} else {
+		psizes = mm->context.high_slices_psize;
+		index = GET_HIGH_SLICE_INDEX(addr);
+	}
+
+	return (psizes >> (index * 4)) & 0xf;
+}
+EXPORT_SYMBOL_GPL(get_slice_psize);
+
+/*
+ * This is called by hash_page when it needs to do a lazy conversion of
+ * an address space from real 64K pages to combo 4K pages (typically
+ * when hitting a non cacheable mapping on a processor or hypervisor
+ * that won't allow them for 64K pages).
+ *
+ * This is also called in init_new_context() to change back the user
+ * psize from whatever the parent context had it set to
+ *
+ * This function will only change the content of the {low,high)_slice_psize
+ * masks, it will not flush SLBs as this shall be handled lazily by the
+ * caller.
+ */
+void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
+{
+	unsigned long flags, lpsizes, hpsizes;
+	unsigned int old_psize;
+	int i;
+
+	slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize);
+
+	spin_lock_irqsave(&slice_convert_lock, flags);
+
+	old_psize = mm->context.user_psize;
+	slice_dbg(" old_psize=%d\n", old_psize);
+	if (old_psize == psize)
+		goto bail;
+
+	mm->context.user_psize = psize;
+	wmb();
+
+	lpsizes = mm->context.low_slices_psize;
+	for (i = 0; i < SLICE_NUM_LOW; i++)
+		if (((lpsizes >> (i * 4)) & 0xf) == old_psize)
+			lpsizes = (lpsizes & ~(0xful << (i * 4))) |
+				(((unsigned long)psize) << (i * 4));
+
+	hpsizes = mm->context.high_slices_psize;
+	for (i = 0; i < SLICE_NUM_HIGH; i++)
+		if (((hpsizes >> (i * 4)) & 0xf) == old_psize)
+			hpsizes = (hpsizes & ~(0xful << (i * 4))) |
+				(((unsigned long)psize) << (i * 4));
+
+	mm->context.low_slices_psize = lpsizes;
+	mm->context.high_slices_psize = hpsizes;
+
+	slice_dbg(" lsps=%lx, hsps=%lx\n",
+		  mm->context.low_slices_psize,
+		  mm->context.high_slices_psize);
+
+ bail:
+	spin_unlock_irqrestore(&slice_convert_lock, flags);
+}
+
+/*
+ * is_hugepage_only_range() is used by generic code to verify wether
+ * a normal mmap mapping (non hugetlbfs) is valid on a given area.
+ *
+ * until the generic code provides a more generic hook and/or starts
+ * calling arch get_unmapped_area for MAP_FIXED (which our implementation
+ * here knows how to deal with), we hijack it to keep standard mappings
+ * away from us.
+ *
+ * because of that generic code limitation, MAP_FIXED mapping cannot
+ * "convert" back a slice with no VMAs to the standard page size, only
+ * get_unmapped_area() can. It would be possible to fix it here but I
+ * prefer working on fixing the generic code instead.
+ *
+ * WARNING: This will not work if hugetlbfs isn't enabled since the
+ * generic code will redefine that function as 0 in that. This is ok
+ * for now as we only use slices with hugetlbfs enabled. This should
+ * be fixed as the generic code gets fixed.
+ */
+int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
+			   unsigned long len)
+{
+	struct slice_mask mask, available;
+
+	mask = slice_range_to_mask(addr, len);
+	available = slice_mask_for_size(mm, mm->context.user_psize);
+
+#if 0 /* too verbose */
+	slice_dbg("is_hugepage_only_range(mm=%p, addr=%lx, len=%lx)\n",
+		 mm, addr, len);
+	slice_print_mask(" mask", mask);
+	slice_print_mask(" available", available);
+#endif
+	return !slice_check_fit(mask, available);
+}
+
diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
index fec5152..a7f5a76 100644
--- a/arch/powerpc/platforms/cell/spu_base.c
+++ b/arch/powerpc/platforms/cell/spu_base.c
@@ -144,12 +144,11 @@
 
 	switch(REGION_ID(ea)) {
 	case USER_REGION_ID:
-#ifdef CONFIG_HUGETLB_PAGE
-		if (in_hugepage_area(mm->context, ea))
-			psize = mmu_huge_psize;
-		else
+#ifdef CONFIG_PPC_MM_SLICES
+		psize = get_slice_psize(mm, ea);
+#else
+		psize = mm->context.user_psize;
 #endif
-			psize = mm->context.user_psize;
 		vsid = (get_vsid(mm->context.id, ea) << SLB_VSID_SHIFT) |
 				SLB_VSID_USER;
 		break;
diff --git a/include/asm-powerpc/mmu-hash64.h b/include/asm-powerpc/mmu-hash64.h
index 6739457..e2ca55b 100644
--- a/include/asm-powerpc/mmu-hash64.h
+++ b/include/asm-powerpc/mmu-hash64.h
@@ -350,10 +350,13 @@
 
 typedef struct {
 	mm_context_id_t id;
-	u16 user_psize;			/* page size index */
-	u16 sllp;			/* SLB entry page size encoding */
-#ifdef CONFIG_HUGETLB_PAGE
-	u16 low_htlb_areas, high_htlb_areas;
+	u16 user_psize;		/* page size index */
+
+#ifdef CONFIG_PPC_MM_SLICES
+	u64 low_slices_psize;	/* SLB page size encodings */
+	u64 high_slices_psize;  /* 4 bits per slice for now */
+#else
+	u16 sllp;		/* SLB page size encoding */
 #endif
 	unsigned long vdso_base;
 } mm_context_t;
diff --git a/include/asm-powerpc/paca.h b/include/asm-powerpc/paca.h
index cf95274..c6a5b17 100644
--- a/include/asm-powerpc/paca.h
+++ b/include/asm-powerpc/paca.h
@@ -83,8 +83,8 @@
 
 	mm_context_t context;
 	u16 vmalloc_sllp;
-	u16 slb_cache[SLB_CACHE_ENTRIES];
 	u16 slb_cache_ptr;
+	u16 slb_cache[SLB_CACHE_ENTRIES];
 
 	/*
 	 * then miscellaneous read-write fields
diff --git a/include/asm-powerpc/page_64.h b/include/asm-powerpc/page_64.h
index eab779c..3448a3d 100644
--- a/include/asm-powerpc/page_64.h
+++ b/include/asm-powerpc/page_64.h
@@ -88,58 +88,56 @@
 
 #endif /* __ASSEMBLY__ */
 
-#ifdef CONFIG_HUGETLB_PAGE
+#ifdef CONFIG_PPC_MM_SLICES
 
-#define HTLB_AREA_SHIFT		40
-#define HTLB_AREA_SIZE		(1UL << HTLB_AREA_SHIFT)
-#define GET_HTLB_AREA(x)	((x) >> HTLB_AREA_SHIFT)
+#define SLICE_LOW_SHIFT		28
+#define SLICE_HIGH_SHIFT	40
 
-#define LOW_ESID_MASK(addr, len)    \
-	(((1U << (GET_ESID(min((addr)+(len)-1, 0x100000000UL))+1)) \
-	  - (1U << GET_ESID(min((addr), 0x100000000UL)))) & 0xffff)
-#define HTLB_AREA_MASK(addr, len)   (((1U << (GET_HTLB_AREA(addr+len-1)+1)) \
-		                      - (1U << GET_HTLB_AREA(addr))) & 0xffff)
+#define SLICE_LOW_TOP		(0x100000000ul)
+#define SLICE_NUM_LOW		(SLICE_LOW_TOP >> SLICE_LOW_SHIFT)
+#define SLICE_NUM_HIGH		(PGTABLE_RANGE >> SLICE_HIGH_SHIFT)
+
+#define GET_LOW_SLICE_INDEX(addr)	((addr) >> SLICE_LOW_SHIFT)
+#define GET_HIGH_SLICE_INDEX(addr)	((addr) >> SLICE_HIGH_SHIFT)
+
+#ifndef __ASSEMBLY__
+
+struct slice_mask {
+	u16 low_slices;
+	u16 high_slices;
+};
+
+struct mm_struct;
+
+extern unsigned long slice_get_unmapped_area(unsigned long addr,
+					     unsigned long len,
+					     unsigned long flags,
+					     unsigned int psize,
+					     int topdown,
+					     int use_cache);
+
+extern unsigned int get_slice_psize(struct mm_struct *mm,
+				    unsigned long addr);
+
+extern void slice_init_context(struct mm_struct *mm, unsigned int psize);
+extern void slice_set_user_psize(struct mm_struct *mm, unsigned int psize);
 
 #define ARCH_HAS_HUGEPAGE_ONLY_RANGE
+extern int is_hugepage_only_range(struct mm_struct *m,
+				  unsigned long addr,
+				  unsigned long len);
+
+#endif /* __ASSEMBLY__ */
+#else
+#define slice_init()
+#endif /* CONFIG_PPC_MM_SLICES */
+
+#ifdef CONFIG_HUGETLB_PAGE
+
 #define ARCH_HAS_HUGETLB_FREE_PGD_RANGE
-#define ARCH_HAS_PREPARE_HUGEPAGE_RANGE
 #define ARCH_HAS_SETCLEAR_HUGE_PTE
-
-#define touches_hugepage_low_range(mm, addr, len) \
-	(((addr) < 0x100000000UL) \
-	 && (LOW_ESID_MASK((addr), (len)) & (mm)->context.low_htlb_areas))
-#define touches_hugepage_high_range(mm, addr, len) \
-	((((addr) + (len)) > 0x100000000UL) \
-	  && (HTLB_AREA_MASK((addr), (len)) & (mm)->context.high_htlb_areas))
-
-#define __within_hugepage_low_range(addr, len, segmask) \
-	( (((addr)+(len)) <= 0x100000000UL) \
-	  && ((LOW_ESID_MASK((addr), (len)) | (segmask)) == (segmask)))
-#define within_hugepage_low_range(addr, len) \
-	__within_hugepage_low_range((addr), (len), \
-				    current->mm->context.low_htlb_areas)
-#define __within_hugepage_high_range(addr, len, zonemask) \
-	( ((addr) >= 0x100000000UL) \
-	  && ((HTLB_AREA_MASK((addr), (len)) | (zonemask)) == (zonemask)))
-#define within_hugepage_high_range(addr, len) \
-	__within_hugepage_high_range((addr), (len), \
-				    current->mm->context.high_htlb_areas)
-
-#define is_hugepage_only_range(mm, addr, len) \
-	(touches_hugepage_high_range((mm), (addr), (len)) || \
-	  touches_hugepage_low_range((mm), (addr), (len)))
 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 
-#define in_hugepage_area(context, addr) \
-	(cpu_has_feature(CPU_FTR_16M_PAGE) && \
-	 ( ( (addr) >= 0x100000000UL) \
-	   ? ((1 << GET_HTLB_AREA(addr)) & (context).high_htlb_areas) \
-	   : ((1 << GET_ESID(addr)) & (context).low_htlb_areas) ) )
-
-#else /* !CONFIG_HUGETLB_PAGE */
-
-#define in_hugepage_area(mm, addr)	0
-
 #endif /* !CONFIG_HUGETLB_PAGE */
 
 #ifdef MODULE