Merge branch 'akpm' (fixes from Andrew Morton)

Merge patch-bomb from Andrew Morton:
 - part of OCFS2 (review is laggy again)
 - procfs
 - slab
 - all of MM
 - zram, zbud
 - various other random things: arch, filesystems.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits)
  nosave: consolidate __nosave_{begin,end} in <asm/sections.h>
  include/linux/screen_info.h: remove unused ORIG_* macros
  kernel/sys.c: compat sysinfo syscall: fix undefined behavior
  kernel/sys.c: whitespace fixes
  acct: eliminate compile warning
  kernel/async.c: switch to pr_foo()
  include/linux/blkdev.h: use NULL instead of zero
  include/linux/kernel.h: deduplicate code implementing clamp* macros
  include/linux/kernel.h: rewrite min3, max3 and clamp using min and max
  alpha: use Kbuild logic to include <asm-generic/sections.h>
  frv: remove deprecated IRQF_DISABLED
  frv: remove unused cpuinfo_frv and friends to fix future build error
  zbud: avoid accessing last unused freelist
  zsmalloc: simplify init_zspage free obj linking
  mm/zsmalloc.c: correct comment for fullness group computation
  zram: use notify_free to account all free notifications
  zram: report maximum used memory
  zram: zram memory size limitation
  zsmalloc: change return value unit of zs_get_total_size_bytes
  zsmalloc: move pages_allocated to zs_pool
  ...

9 files changed, 136 insertions, 161 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d9d32de9628c..18f392f8b744 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -14,6 +14,7 @@ config ARM
 	select CLONE_BACKWARDS
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select GENERIC_ALLOCATOR
 	select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_IDLE_POLL_SETUP
@@ -61,6 +62,7 @@ config ARM
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_UID16
@@ -1659,6 +1661,10 @@ config ARCH_SELECT_MEMORY_MODEL
 config HAVE_ARCH_PFN_VALID
 	def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
 
+config HAVE_GENERIC_RCU_GUP
+	def_bool y
+	depends on ARM_LPAE
+
 config HIGHMEM
 	bool "High Memory Support"
 	depends on MMU
diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h
index 219ac88a9542..f0279411847d 100644
--- a/arch/arm/include/asm/pgtable-2level.h
+++ b/arch/arm/include/asm/pgtable-2level.h
@@ -182,6 +182,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 #define pmd_addr_end(addr,end) (end)
 
 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
+#define pte_special(pte)	(0)
+static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 
 /*
  * We don't have huge page support for short descriptors, for the moment
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 06e0bc0f8b00..a31ecdad4b59 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -213,10 +213,19 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 #define pmd_isclear(pmd, val)	(!(pmd_val(pmd) & (val)))
 
 #define pmd_young(pmd)		(pmd_isset((pmd), PMD_SECT_AF))
+#define pte_special(pte)	(pte_isset((pte), L_PTE_SPECIAL))
+static inline pte_t pte_mkspecial(pte_t pte)
+{
+	pte_val(pte) |= L_PTE_SPECIAL;
+	return pte;
+}
+#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define __HAVE_ARCH_PMD_WRITE
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
+#define pud_page(pud)		pmd_page(__pmd(pud_val(pud)))
+#define pud_write(pud)		pmd_write(__pmd(pud_val(pud)))
 
 #define pmd_hugewillfault(pmd)	(!pmd_young(pmd) || !pmd_write(pmd))
 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
@@ -224,6 +233,12 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !pmd_table(pmd))
 #define pmd_trans_splitting(pmd) (pmd_isset((pmd), L_PMD_SECT_SPLITTING))
+
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
+void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
+			  pmd_t *pmdp);
+#endif
 #endif
 
 #define PMD_BIT_FUNC(fn,op) \
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 01baef07cd0c..90aa4583b308 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -226,7 +226,6 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 #define pte_dirty(pte)		(pte_isset((pte), L_PTE_DIRTY))
 #define pte_young(pte)		(pte_isset((pte), L_PTE_YOUNG))
 #define pte_exec(pte)		(pte_isclear((pte), L_PTE_XN))
-#define pte_special(pte)	(0)
 
 #define pte_valid_user(pte)	\
 	(pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))
@@ -245,7 +244,8 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 	unsigned long ext = 0;
 
 	if (addr < TASK_SIZE && pte_valid_user(pteval)) {
-		__sync_icache_dcache(pteval);
+		if (!pte_special(pteval))
+			__sync_icache_dcache(pteval);
 		ext |= PTE_EXT_NG;
 	}
 
@@ -264,8 +264,6 @@ PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);
 PTE_BIT_FUNC(mkexec,   &= ~L_PTE_XN);
 PTE_BIT_FUNC(mknexec,   |= L_PTE_XN);
 
-static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index f1a0dace3efe..3cadb726ec88 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -35,12 +35,39 @@
 
 #define MMU_GATHER_BUNDLE	8
 
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+static inline void __tlb_remove_table(void *_table)
+{
+	free_page_and_swap_cache((struct page *)_table);
+}
+
+struct mmu_table_batch {
+	struct rcu_head		rcu;
+	unsigned int		nr;
+	void			*tables[0];
+};
+
+#define MAX_TABLE_BATCH		\
+	((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
+
+extern void tlb_table_flush(struct mmu_gather *tlb);
+extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
+
+#define tlb_remove_entry(tlb, entry)	tlb_remove_table(tlb, entry)
+#else
+#define tlb_remove_entry(tlb, entry)	tlb_remove_page(tlb, entry)
+#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
+
 /*
  * TLB handling.  This allows us to remove pages from the page
  * tables, and efficiently handle the TLB issues.
  */
 struct mmu_gather {
 	struct mm_struct	*mm;
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+	struct mmu_table_batch	*batch;
+	unsigned int		need_flush;
+#endif
 	unsigned int		fullmm;
 	struct vm_area_struct	*vma;
 	unsigned long		start, end;
@@ -101,6 +128,9 @@ static inline void __tlb_alloc_page(struct mmu_gather *tlb)
 static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
 {
 	tlb_flush(tlb);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+	tlb_table_flush(tlb);
+#endif
 }
 
 static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
@@ -129,6 +159,10 @@ tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start
 	tlb->pages = tlb->local;
 	tlb->nr = 0;
 	__tlb_alloc_page(tlb);
+
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+	tlb->batch = NULL;
+#endif
 }
 
 static inline void
@@ -205,7 +239,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
 	tlb_add_flush(tlb, addr + SZ_1M);
 #endif
 
-	tlb_remove_page(tlb, pte);
+	tlb_remove_entry(tlb, pte);
 }
 
 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
@@ -213,7 +247,7 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 {
 #ifdef CONFIG_ARM_LPAE
 	tlb_add_flush(tlb, addr);
-	tlb_remove_page(tlb, virt_to_page(pmdp));
+	tlb_remove_entry(tlb, virt_to_page(pmdp));
 #endif
 }
 
diff --git a/arch/arm/kernel/hibernate.c b/arch/arm/kernel/hibernate.c
index bb8b79648643..c4cc50e58c13 100644
--- a/arch/arm/kernel/hibernate.c
+++ b/arch/arm/kernel/hibernate.c
@@ -21,8 +21,7 @@
 #include <asm/idmap.h>
 #include <asm/suspend.h>
 #include <asm/memory.h>
-
-extern const void __nosave_begin, __nosave_end;
+#include <asm/sections.h>
 
 int pfn_is_nosave(unsigned long pfn)
 {
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7a996aaa061e..c245d903927f 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -12,6 +12,7 @@
 #include <linux/bootmem.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/genalloc.h>
 #include <linux/gfp.h>
 #include <linux/errno.h>
 #include <linux/list.h>
@@ -298,57 +299,29 @@ static void *
 __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
 	const void *caller)
 {
-	struct vm_struct *area;
-	unsigned long addr;
-
 	/*
 	 * DMA allocation can be mapped to user space, so lets
 	 * set VM_USERMAP flags too.
 	 */
-	area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
-				  caller);
-	if (!area)
-		return NULL;
-	addr = (unsigned long)area->addr;
-	area->phys_addr = __pfn_to_phys(page_to_pfn(page));
-
-	if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
-		vunmap((void *)addr);
-		return NULL;
-	}
-	return (void *)addr;
+	return dma_common_contiguous_remap(page, size,
+			VM_ARM_DMA_CONSISTENT | VM_USERMAP,
+			prot, caller);
 }
 
 static void __dma_free_remap(void *cpu_addr, size_t size)
 {
-	unsigned int flags = VM_ARM_DMA_CONSISTENT | VM_USERMAP;
-	struct vm_struct *area = find_vm_area(cpu_addr);
-	if (!area || (area->flags & flags) != flags) {
-		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
-		return;
-	}
-	unmap_kernel_range((unsigned long)cpu_addr, size);
-	vunmap(cpu_addr);
+	dma_common_free_remap(cpu_addr, size,
+			VM_ARM_DMA_CONSISTENT | VM_USERMAP);
 }
 
 #define DEFAULT_DMA_COHERENT_POOL_SIZE	SZ_256K
+static struct gen_pool *atomic_pool;
 
-struct dma_pool {
-	size_t size;
-	spinlock_t lock;
-	unsigned long *bitmap;
-	unsigned long nr_pages;
-	void *vaddr;
-	struct page **pages;
-};
-
-static struct dma_pool atomic_pool = {
-	.size = DEFAULT_DMA_COHERENT_POOL_SIZE,
-};
+static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;
 
 static int __init early_coherent_pool(char *p)
 {
-	atomic_pool.size = memparse(p, &p);
+	atomic_pool_size = memparse(p, &p);
 	return 0;
 }
 early_param("coherent_pool", early_coherent_pool);
@@ -358,14 +331,14 @@ void __init init_dma_coherent_pool_size(unsigned long size)
 	/*
 	 * Catch any attempt to set the pool size too late.
 	 */
-	BUG_ON(atomic_pool.vaddr);
+	BUG_ON(atomic_pool);
 
 	/*
 	 * Set architecture specific coherent pool size only if
 	 * it has not been changed by kernel command line parameter.
 	 */
-	if (atomic_pool.size == DEFAULT_DMA_COHERENT_POOL_SIZE)
-		atomic_pool.size = size;
+	if (atomic_pool_size == DEFAULT_DMA_COHERENT_POOL_SIZE)
+		atomic_pool_size = size;
 }
 
 /*
@@ -373,52 +346,44 @@ void __init init_dma_coherent_pool_size(unsigned long size)
  */
 static int __init atomic_pool_init(void)
 {
-	struct dma_pool *pool = &atomic_pool;
 	pgprot_t prot = pgprot_dmacoherent(PAGE_KERNEL);
 	gfp_t gfp = GFP_KERNEL | GFP_DMA;
-	unsigned long nr_pages = pool->size >> PAGE_SHIFT;
-	unsigned long *bitmap;
 	struct page *page;
-	struct page **pages;
 	void *ptr;
-	int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
 
-	bitmap = kzalloc(bitmap_size, GFP_KERNEL);
-	if (!bitmap)
-		goto no_bitmap;
-
-	pages = kzalloc(nr_pages * sizeof(struct page *), GFP_KERNEL);
-	if (!pages)
-		goto no_pages;
+	atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (!atomic_pool)
+		goto out;
 
 	if (dev_get_cma_area(NULL))
-		ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page,
-					      atomic_pool_init);
+		ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,
+					      &page, atomic_pool_init);
 	else
-		ptr = __alloc_remap_buffer(NULL, pool->size, gfp, prot, &page,
-					   atomic_pool_init);
+		ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot,
+					   &page, atomic_pool_init);
 	if (ptr) {
-		int i;
-
-		for (i = 0; i < nr_pages; i++)
-			pages[i] = page + i;
-
-		spin_lock_init(&pool->lock);
-		pool->vaddr = ptr;
-		pool->pages = pages;
-		pool->bitmap = bitmap;
-		pool->nr_pages = nr_pages;
-		pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
-		       (unsigned)pool->size / 1024);
+		int ret;
+
+		ret = gen_pool_add_virt(atomic_pool, (unsigned long)ptr,
+					page_to_phys(page),
+					atomic_pool_size, -1);
+		if (ret)
+			goto destroy_genpool;
+
+		gen_pool_set_algo(atomic_pool,
+				gen_pool_first_fit_order_align,
+				(void *)PAGE_SHIFT);
+		pr_info("DMA: preallocated %zd KiB pool for atomic coherent allocations\n",
+		       atomic_pool_size / 1024);
 		return 0;
 	}
 
-	kfree(pages);
-no_pages:
-	kfree(bitmap);
-no_bitmap:
-	pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
-	       (unsigned)pool->size / 1024);
+destroy_genpool:
+	gen_pool_destroy(atomic_pool);
+	atomic_pool = NULL;
+out:
+	pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent allocation\n",
+	       atomic_pool_size / 1024);
 	return -ENOMEM;
 }
 /*
@@ -522,76 +487,36 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
 
 static void *__alloc_from_pool(size_t size, struct page **ret_page)
 {
-	struct dma_pool *pool = &atomic_pool;
-	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned int pageno;
-	unsigned long flags;
+	unsigned long val;
 	void *ptr = NULL;
-	unsigned long align_mask;
 
-	if (!pool->vaddr) {
+	if (!atomic_pool) {
 		WARN(1, "coherent pool not initialised!\n");
 		return NULL;
 	}
 
-	/*
-	 * Align the region allocation - allocations from pool are rather
-	 * small, so align them to their order in pages, minimum is a page
-	 * size. This helps reduce fragmentation of the DMA space.
-	 */
-	align_mask = (1 << get_order(size)) - 1;
-
-	spin_lock_irqsave(&pool->lock, flags);
-	pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages,
-					    0, count, align_mask);
-	if (pageno < pool->nr_pages) {
-		bitmap_set(pool->bitmap, pageno, count);
-		ptr = pool->vaddr + PAGE_SIZE * pageno;
-		*ret_page = pool->pages[pageno];
-	} else {
-		pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n"
-			    "Please increase it with coherent_pool= kernel parameter!\n",
-			    (unsigned)pool->size / 1024);
+	val = gen_pool_alloc(atomic_pool, size);
+	if (val) {
+		phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
+
+		*ret_page = phys_to_page(phys);
+		ptr = (void *)val;
 	}
-	spin_unlock_irqrestore(&pool->lock, flags);
 
 	return ptr;
 }
 
 static bool __in_atomic_pool(void *start, size_t size)
 {
-	struct dma_pool *pool = &atomic_pool;
-	void *end = start + size;
-	void *pool_start = pool->vaddr;
-	void *pool_end = pool->vaddr + pool->size;
-
-	if (start < pool_start || start >= pool_end)
-		return false;
-
-	if (end <= pool_end)
-		return true;
-
-	WARN(1, "Wrong coherent size(%p-%p) from atomic pool(%p-%p)\n",
-	     start, end - 1, pool_start, pool_end - 1);
-
-	return false;
+	return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
 }
 
 static int __free_from_pool(void *start, size_t size)
 {
-	struct dma_pool *pool = &atomic_pool;
-	unsigned long pageno, count;
-	unsigned long flags;
-
 	if (!__in_atomic_pool(start, size))
 		return 0;
 
-	pageno = (start - pool->vaddr) >> PAGE_SHIFT;
-	count = size >> PAGE_SHIFT;
-
-	spin_lock_irqsave(&pool->lock, flags);
-	bitmap_clear(pool->bitmap, pageno, count);
-	spin_unlock_irqrestore(&pool->lock, flags);
+	gen_pool_free(atomic_pool, (unsigned long)start, size);
 
 	return 1;
 }
@@ -1271,29 +1196,8 @@ static void *
 __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
 		    const void *caller)
 {
-	unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	struct vm_struct *area;
-	unsigned long p;
-
-	area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
-				  caller);
-	if (!area)
-		return NULL;
-
-	area->pages = pages;
-	area->nr_pages = nr_pages;
-	p = (unsigned long)area->addr;
-
-	for (i = 0; i < nr_pages; i++) {
-		phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
-		if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
-			goto err;
-		p += PAGE_SIZE;
-	}
-	return area->addr;
-err:
-	unmap_kernel_range((unsigned long)area->addr, size);
-	vunmap(area->addr);
+	return dma_common_pages_remap(pages, size,
+			VM_ARM_DMA_CONSISTENT | VM_USERMAP, prot, caller);
 	return NULL;
 }
 
@@ -1355,11 +1259,13 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si
 
 static struct page **__atomic_get_pages(void *addr)
 {
-	struct dma_pool *pool = &atomic_pool;
-	struct page **pages = pool->pages;
-	int offs = (addr - pool->vaddr) >> PAGE_SHIFT;
+	struct page *page;
+	phys_addr_t phys;
+
+	phys = gen_pool_virt_to_phys(atomic_pool, (unsigned long)addr);
+	page = phys_to_page(phys);
 
-	return pages + offs;
+	return (struct page **)page;
 }
 
 static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
@@ -1501,8 +1407,8 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 	}
 
 	if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) {
-		unmap_kernel_range((unsigned long)cpu_addr, size);
-		vunmap(cpu_addr);
+		dma_common_free_remap(cpu_addr, size,
+			VM_ARM_DMA_CONSISTENT | VM_USERMAP);
 	}
 
 	__iommu_remove_mapping(dev, handle, size);
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 43d54f5b26b9..265b836b3bd1 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -400,3 +400,18 @@ void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned l
 	 */
 	__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
 }
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
+			  pmd_t *pmdp)
+{
+	pmd_t pmd = pmd_mksplitting(*pmdp);
+	VM_BUG_ON(address & ~PMD_MASK);
+	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+
+	/* dummy IPI to serialise against fast_gup */
+	kick_all_cpus_sync();
+}
+#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 9221645dd192..92bba32d9230 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -322,7 +322,7 @@ void __init arm_memblock_init(const struct machine_desc *mdesc)
 	 * reserve memory for DMA contigouos allocations,
 	 * must come from DMA area inside low memory
 	 */
-	dma_contiguous_reserve(min(arm_dma_limit, arm_lowmem_limit));
+	dma_contiguous_reserve(arm_dma_limit);
 
 	arm_memblock_steal_permitted = false;
 	memblock_dump_all();