Merge commit 'a849088aa1' from rmk/fixes into cleanup/io-pci

As Stephen Rothwell reports, a849088aa155 ("ARM: Fix ioremap() of
address zero") from the arm-current tree and commit c2794437091a ("ARM:
Add fixed PCI i/o mapping") from the arm-soc tree conflict in
a nontrivial way in arch/arm/mm/mmu.c.

Rob Herring explains:
The PCI i/o reserved area has a dummy physical address of 0 and
needs to be skipped by ioremap searches. So we don't set
VM_ARM_STATIC_MAPPING to prevent matches by ioremap. The vm_struct
settings don't really matter when we do the real mapping of the
i/o space.

Since commit a849088aa155 is at the start of the fixes branch
in the arm tree, we can merge it into the branch that contains
the other ioremap changes.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>

10 files changed, 304 insertions, 355 deletions

diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 806cc4f63516..119bc52ab93e 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -14,6 +14,7 @@
 #include <linux/percpu.h>
 
 #include <asm/mmu_context.h>
+#include <asm/thread_notify.h>
 #include <asm/tlbflush.h>
 
 static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
@@ -48,6 +49,40 @@ void cpu_set_reserved_ttbr0(void)
 }
 #endif
 
+#ifdef CONFIG_PID_IN_CONTEXTIDR
+static int contextidr_notifier(struct notifier_block *unused, unsigned long cmd,
+			       void *t)
+{
+	u32 contextidr;
+	pid_t pid;
+	struct thread_info *thread = t;
+
+	if (cmd != THREAD_NOTIFY_SWITCH)
+		return NOTIFY_DONE;
+
+	pid = task_pid_nr(thread->task) << ASID_BITS;
+	asm volatile(
+	"	mrc	p15, 0, %0, c13, c0, 1\n"
+	"	bfi	%1, %0, #0, %2\n"
+	"	mcr	p15, 0, %1, c13, c0, 1\n"
+	: "=r" (contextidr), "+r" (pid)
+	: "I" (ASID_BITS));
+	isb();
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block contextidr_notifier_block = {
+	.notifier_call = contextidr_notifier,
+};
+
+static int __init contextidr_notifier_init(void)
+{
+	return thread_register_notifier(&contextidr_notifier_block);
+}
+arch_initcall(contextidr_notifier_init);
+#endif
+
 /*
  * We fork()ed a process, and we need a new context for the child
  * to run in.
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4044abcf6f9d..4e7d1182e8a3 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -22,13 +22,14 @@
 #include <linux/memblock.h>
 #include <linux/slab.h>
 #include <linux/iommu.h>
+#include <linux/io.h>
 #include <linux/vmalloc.h>
+#include <linux/sizes.h>
 
 #include <asm/memory.h>
 #include <asm/highmem.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
-#include <asm/sizes.h>
 #include <asm/mach/arch.h>
 #include <asm/dma-iommu.h>
 #include <asm/mach/map.h>
@@ -72,7 +73,7 @@ static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
 	     unsigned long offset, size_t size, enum dma_data_direction dir,
 	     struct dma_attrs *attrs)
 {
-	if (!arch_is_coherent())
+	if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
 		__dma_page_cpu_to_dev(page, offset, size, dir);
 	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 }
@@ -95,7 +96,7 @@ static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir,
 		struct dma_attrs *attrs)
 {
-	if (!arch_is_coherent())
+	if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
 		__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
 				      handle & ~PAGE_MASK, size, dir);
 }
@@ -124,6 +125,7 @@ struct dma_map_ops arm_dma_ops = {
 	.alloc			= arm_dma_alloc,
 	.free			= arm_dma_free,
 	.mmap			= arm_dma_mmap,
+	.get_sgtable		= arm_dma_get_sgtable,
 	.map_page		= arm_dma_map_page,
 	.unmap_page		= arm_dma_unmap_page,
 	.map_sg			= arm_dma_map_sg,
@@ -217,115 +219,70 @@ static void __dma_free_buffer(struct page *page, size_t size)
 }
 
 #ifdef CONFIG_MMU
+#ifdef CONFIG_HUGETLB_PAGE
+#error ARM Coherent DMA allocator does not (yet) support huge TLB
+#endif
 
-#define CONSISTENT_OFFSET(x)	(((unsigned long)(x) - consistent_base) >> PAGE_SHIFT)
-#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PMD_SHIFT)
-
-/*
- * These are the page tables (2MB each) covering uncached, DMA consistent allocations
- */
-static pte_t **consistent_pte;
-
-#define DEFAULT_CONSISTENT_DMA_SIZE SZ_2M
+static void *__alloc_from_contiguous(struct device *dev, size_t size,
+				     pgprot_t prot, struct page **ret_page);
 
-static unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE;
+static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
+				 pgprot_t prot, struct page **ret_page,
+				 const void *caller);
 
-void __init init_consistent_dma_size(unsigned long size)
+static void *
+__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
+	const void *caller)
 {
-	unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M);
+	struct vm_struct *area;
+	unsigned long addr;
 
-	BUG_ON(consistent_pte); /* Check we're called before DMA region init */
-	BUG_ON(base < VMALLOC_END);
+	/*
+	 * 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));
 
-	/* Grow region to accommodate specified size  */
-	if (base < consistent_base)
-		consistent_base = base;
+	if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
+		vunmap((void *)addr);
+		return NULL;
+	}
+	return (void *)addr;
 }
 
-#include "vmregion.h"
-
-static struct arm_vmregion_head consistent_head = {
-	.vm_lock	= __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock),
-	.vm_list	= LIST_HEAD_INIT(consistent_head.vm_list),
-	.vm_end		= CONSISTENT_END,
-};
-
-#ifdef CONFIG_HUGETLB_PAGE
-#error ARM Coherent DMA allocator does not (yet) support huge TLB
-#endif
-
-/*
- * Initialise the consistent memory allocation.
- */
-static int __init consistent_init(void)
+static void __dma_free_remap(void *cpu_addr, size_t size)
 {
-	int ret = 0;
-	pgd_t *pgd;
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
-	int i = 0;
-	unsigned long base = consistent_base;
-	unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT;
-
-	if (IS_ENABLED(CONFIG_CMA) && !IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
-		return 0;
-
-	consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL);
-	if (!consistent_pte) {
-		pr_err("%s: no memory\n", __func__);
-		return -ENOMEM;
+	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;
 	}
-
-	pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END);
-	consistent_head.vm_start = base;
-
-	do {
-		pgd = pgd_offset(&init_mm, base);
-
-		pud = pud_alloc(&init_mm, pgd, base);
-		if (!pud) {
-			pr_err("%s: no pud tables\n", __func__);
-			ret = -ENOMEM;
-			break;
-		}
-
-		pmd = pmd_alloc(&init_mm, pud, base);
-		if (!pmd) {
-			pr_err("%s: no pmd tables\n", __func__);
-			ret = -ENOMEM;
-			break;
-		}
-		WARN_ON(!pmd_none(*pmd));
-
-		pte = pte_alloc_kernel(pmd, base);
-		if (!pte) {
-			pr_err("%s: no pte tables\n", __func__);
-			ret = -ENOMEM;
-			break;
-		}
-
-		consistent_pte[i++] = pte;
-		base += PMD_SIZE;
-	} while (base < CONSISTENT_END);
-
-	return ret;
+	unmap_kernel_range((unsigned long)cpu_addr, size);
+	vunmap(cpu_addr);
 }
-core_initcall(consistent_init);
 
-static void *__alloc_from_contiguous(struct device *dev, size_t size,
-				     pgprot_t prot, struct page **ret_page);
-
-static struct arm_vmregion_head coherent_head = {
-	.vm_lock	= __SPIN_LOCK_UNLOCKED(&coherent_head.vm_lock),
-	.vm_list	= LIST_HEAD_INIT(coherent_head.vm_list),
+struct dma_pool {
+	size_t size;
+	spinlock_t lock;
+	unsigned long *bitmap;
+	unsigned long nr_pages;
+	void *vaddr;
+	struct page *page;
 };
 
-static size_t coherent_pool_size = DEFAULT_CONSISTENT_DMA_SIZE / 8;
+static struct dma_pool atomic_pool = {
+	.size = SZ_256K,
+};
 
 static int __init early_coherent_pool(char *p)
 {
-	coherent_pool_size = memparse(p, &p);
+	atomic_pool.size = memparse(p, &p);
 	return 0;
 }
 early_param("coherent_pool", early_coherent_pool);
@@ -333,32 +290,45 @@ early_param("coherent_pool", early_coherent_pool);
 /*
  * Initialise the coherent pool for atomic allocations.
  */
-static int __init coherent_init(void)
+static int __init atomic_pool_init(void)
 {
+	struct dma_pool *pool = &atomic_pool;
 	pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);
-	size_t size = coherent_pool_size;
+	unsigned long nr_pages = pool->size >> PAGE_SHIFT;
+	unsigned long *bitmap;
 	struct page *page;
 	void *ptr;
+	int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
 
-	if (!IS_ENABLED(CONFIG_CMA))
-		return 0;
+	bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!bitmap)
+		goto no_bitmap;
 
-	ptr = __alloc_from_contiguous(NULL, size, prot, &page);
+	if (IS_ENABLED(CONFIG_CMA))
+		ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page);
+	else
+		ptr = __alloc_remap_buffer(NULL, pool->size, GFP_KERNEL, prot,
+					   &page, NULL);
 	if (ptr) {
-		coherent_head.vm_start = (unsigned long) ptr;
-		coherent_head.vm_end = (unsigned long) ptr + size;
-		printk(KERN_INFO "DMA: preallocated %u KiB pool for atomic coherent allocations\n",
-		       (unsigned)size / 1024);
+		spin_lock_init(&pool->lock);
+		pool->vaddr = ptr;
+		pool->page = page;
+		pool->bitmap = bitmap;
+		pool->nr_pages = nr_pages;
+		pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
+		       (unsigned)pool->size / 1024);
 		return 0;
 	}
-	printk(KERN_ERR "DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
-	       (unsigned)size / 1024);
+	kfree(bitmap);
+no_bitmap:
+	pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
+	       (unsigned)pool->size / 1024);
 	return -ENOMEM;
 }
 /*
  * CMA is activated by core_initcall, so we must be called after it.
  */
-postcore_initcall(coherent_init);
+postcore_initcall(atomic_pool_init);
 
 struct dma_contig_early_reserve {
 	phys_addr_t base;
@@ -388,7 +358,7 @@ void __init dma_contiguous_remap(void)
 		if (end > arm_lowmem_limit)
 			end = arm_lowmem_limit;
 		if (start >= end)
-			return;
+			continue;
 
 		map.pfn = __phys_to_pfn(start);
 		map.virtual = __phys_to_virt(start);
@@ -406,112 +376,6 @@ void __init dma_contiguous_remap(void)
 	}
 }
 
-static void *
-__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
-	const void *caller)
-{
-	struct arm_vmregion *c;
-	size_t align;
-	int bit;
-
-	if (!consistent_pte) {
-		pr_err("%s: not initialised\n", __func__);
-		dump_stack();
-		return NULL;
-	}
-
-	/*
-	 * Align the virtual region allocation - maximum alignment is
-	 * a section size, minimum is a page size.  This helps reduce
-	 * fragmentation of the DMA space, and also prevents allocations
-	 * smaller than a section from crossing a section boundary.
-	 */
-	bit = fls(size - 1);
-	if (bit > SECTION_SHIFT)
-		bit = SECTION_SHIFT;
-	align = 1 << bit;
-
-	/*
-	 * Allocate a virtual address in the consistent mapping region.
-	 */
-	c = arm_vmregion_alloc(&consistent_head, align, size,
-			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM), caller);
-	if (c) {
-		pte_t *pte;
-		int idx = CONSISTENT_PTE_INDEX(c->vm_start);
-		u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
-
-		pte = consistent_pte[idx] + off;
-		c->priv = page;
-
-		do {
-			BUG_ON(!pte_none(*pte));
-
-			set_pte_ext(pte, mk_pte(page, prot), 0);
-			page++;
-			pte++;
-			off++;
-			if (off >= PTRS_PER_PTE) {
-				off = 0;
-				pte = consistent_pte[++idx];
-			}
-		} while (size -= PAGE_SIZE);
-
-		dsb();
-
-		return (void *)c->vm_start;
-	}
-	return NULL;
-}
-
-static void __dma_free_remap(void *cpu_addr, size_t size)
-{
-	struct arm_vmregion *c;
-	unsigned long addr;
-	pte_t *ptep;
-	int idx;
-	u32 off;
-
-	c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
-	if (!c) {
-		pr_err("%s: trying to free invalid coherent area: %p\n",
-		       __func__, cpu_addr);
-		dump_stack();
-		return;
-	}
-
-	if ((c->vm_end - c->vm_start) != size) {
-		pr_err("%s: freeing wrong coherent size (%ld != %d)\n",
-		       __func__, c->vm_end - c->vm_start, size);
-		dump_stack();
-		size = c->vm_end - c->vm_start;
-	}
-
-	idx = CONSISTENT_PTE_INDEX(c->vm_start);
-	off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
-	ptep = consistent_pte[idx] + off;
-	addr = c->vm_start;
-	do {
-		pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
-
-		ptep++;
-		addr += PAGE_SIZE;
-		off++;
-		if (off >= PTRS_PER_PTE) {
-			off = 0;
-			ptep = consistent_pte[++idx];
-		}
-
-		if (pte_none(pte) || !pte_present(pte))
-			pr_crit("%s: bad page in kernel page table\n",
-				__func__);
-	} while (size -= PAGE_SIZE);
-
-	flush_tlb_kernel_range(c->vm_start, c->vm_end);
-
-	arm_vmregion_free(&consistent_head, c);
-}
-
 static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
 			    void *data)
 {
@@ -552,16 +416,17 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
 	return ptr;
 }
 
-static void *__alloc_from_pool(struct device *dev, size_t size,
-			       struct page **ret_page, const void *caller)
+static void *__alloc_from_pool(size_t size, struct page **ret_page)
 {
-	struct arm_vmregion *c;
-	size_t align;
+	struct dma_pool *pool = &atomic_pool;
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned int pageno;
+	unsigned long flags;
+	void *ptr = NULL;
+	unsigned long align_mask;
 
-	if (!coherent_head.vm_start) {
-		printk(KERN_ERR "%s: coherent pool not initialised!\n",
-		       __func__);
-		dump_stack();
+	if (!pool->vaddr) {
+		WARN(1, "coherent pool not initialised!\n");
 		return NULL;
 	}
 
@@ -570,36 +435,42 @@ static void *__alloc_from_pool(struct device *dev, size_t size,
 	 * small, so align them to their order in pages, minimum is a page
 	 * size. This helps reduce fragmentation of the DMA space.
 	 */
-	align = PAGE_SIZE << get_order(size);
-	c = arm_vmregion_alloc(&coherent_head, align, size, 0, caller);
-	if (c) {
-		void *ptr = (void *)c->vm_start;
-		struct page *page = virt_to_page(ptr);
-		*ret_page = page;
-		return ptr;
+	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->page + pageno;
 	}
-	return NULL;
+	spin_unlock_irqrestore(&pool->lock, flags);
+
+	return ptr;
 }
 
-static int __free_from_pool(void *cpu_addr, size_t size)
+static int __free_from_pool(void *start, size_t size)
 {
-	unsigned long start = (unsigned long)cpu_addr;
-	unsigned long end = start + size;
-	struct arm_vmregion *c;
+	struct dma_pool *pool = &atomic_pool;
+	unsigned long pageno, count;
+	unsigned long flags;
 
-	if (start < coherent_head.vm_start || end > coherent_head.vm_end)
+	if (start < pool->vaddr || start > pool->vaddr + pool->size)
 		return 0;
 
-	c = arm_vmregion_find_remove(&coherent_head, (unsigned long)start);
-
-	if ((c->vm_end - c->vm_start) != size) {
-		printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
-		       __func__, c->vm_end - c->vm_start, size);
-		dump_stack();
-		size = c->vm_end - c->vm_start;
+	if (start + size > pool->vaddr + pool->size) {
+		WARN(1, "freeing wrong coherent size from pool\n");
+		return 0;
 	}
 
-	arm_vmregion_free(&coherent_head, c);
+	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);
+
 	return 1;
 }
 
@@ -644,7 +515,7 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
 
 #define __get_dma_pgprot(attrs, prot)	__pgprot(0)
 #define __alloc_remap_buffer(dev, size, gfp, prot, ret, c)	NULL
-#define __alloc_from_pool(dev, size, ret_page, c)		NULL
+#define __alloc_from_pool(size, ret_page)			NULL
 #define __alloc_from_contiguous(dev, size, prot, ret)		NULL
 #define __free_from_pool(cpu_addr, size)			0
 #define __free_from_contiguous(dev, page, size)			do { } while (0)
@@ -702,10 +573,10 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 
 	if (arch_is_coherent() || nommu())
 		addr = __alloc_simple_buffer(dev, size, gfp, &page);
+	else if (gfp & GFP_ATOMIC)
+		addr = __alloc_from_pool(size, &page);
 	else if (!IS_ENABLED(CONFIG_CMA))
 		addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
-	else if (gfp & GFP_ATOMIC)
-		addr = __alloc_from_pool(dev, size, &page, caller);
 	else
 		addr = __alloc_from_contiguous(dev, size, prot, &page);
 
@@ -741,16 +612,22 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 {
 	int ret = -ENXIO;
 #ifdef CONFIG_MMU
+	unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	unsigned long pfn = dma_to_pfn(dev, dma_addr);
+	unsigned long off = vma->vm_pgoff;
+
 	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
 
 	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 		return ret;
 
-	ret = remap_pfn_range(vma, vma->vm_start,
-			      pfn + vma->vm_pgoff,
-			      vma->vm_end - vma->vm_start,
-			      vma->vm_page_prot);
+	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
+		ret = remap_pfn_range(vma, vma->vm_start,
+				      pfn + off,
+				      vma->vm_end - vma->vm_start,
+				      vma->vm_page_prot);
+	}
 #endif	/* CONFIG_MMU */
 
 	return ret;
@@ -771,12 +648,12 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 
 	if (arch_is_coherent() || nommu()) {
 		__dma_free_buffer(page, size);
+	} else if (__free_from_pool(cpu_addr, size)) {
+		return;
 	} else if (!IS_ENABLED(CONFIG_CMA)) {
 		__dma_free_remap(cpu_addr, size);
 		__dma_free_buffer(page, size);
 	} else {
-		if (__free_from_pool(cpu_addr, size))
-			return;
 		/*
 		 * Non-atomic allocations cannot be freed with IRQs disabled
 		 */
@@ -785,6 +662,21 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 	}
 }
 
+int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
+		 void *cpu_addr, dma_addr_t handle, size_t size,
+		 struct dma_attrs *attrs)
+{
+	struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
+	int ret;
+
+	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (unlikely(ret))
+		return ret;
+
+	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+	return 0;
+}
+
 static void dma_cache_maint_page(struct page *page, unsigned long offset,
 	size_t size, enum dma_data_direction dir,
 	void (*op)(const void *, size_t, int))
@@ -998,9 +890,6 @@ static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
 
 static int __init dma_debug_do_init(void)
 {
-#ifdef CONFIG_MMU
-	arm_vmregion_create_proc("dma-mappings", &consistent_head);
-#endif
 	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 	return 0;
 }
@@ -1088,10 +977,10 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t
 
 	return pages;
 error:
-	while (--i)
+	while (i--)
 		if (pages[i])
 			__free_pages(pages[i], 0);
-	if (array_size < PAGE_SIZE)
+	if (array_size <= PAGE_SIZE)
 		kfree(pages);
 	else
 		vfree(pages);
@@ -1106,7 +995,7 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t s
 	for (i = 0; i < count; i++)
 		if (pages[i])
 			__free_pages(pages[i], 0);
-	if (array_size < PAGE_SIZE)
+	if (array_size <= PAGE_SIZE)
 		kfree(pages);
 	else
 		vfree(pages);
@@ -1117,61 +1006,32 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t s
  * Create a CPU mapping for a specified pages
  */
 static void *
-__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
+__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
+		    const void *caller)
 {
-	struct arm_vmregion *c;
-	size_t align;
-	size_t count = size >> PAGE_SHIFT;
-	int bit;
+	unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	struct vm_struct *area;
+	unsigned long p;
 
-	if (!consistent_pte[0]) {
-		pr_err("%s: not initialised\n", __func__);
-		dump_stack();
+	area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
+				  caller);
+	if (!area)
 		return NULL;
-	}
-
-	/*
-	 * Align the virtual region allocation - maximum alignment is
-	 * a section size, minimum is a page size.  This helps reduce
-	 * fragmentation of the DMA space, and also prevents allocations
-	 * smaller than a section from crossing a section boundary.
-	 */
-	bit = fls(size - 1);
-	if (bit > SECTION_SHIFT)
-		bit = SECTION_SHIFT;
-	align = 1 << bit;
-
-	/*
-	 * Allocate a virtual address in the consistent mapping region.
-	 */
-	c = arm_vmregion_alloc(&consistent_head, align, size,
-			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM), NULL);
-	if (c) {
-		pte_t *pte;
-		int idx = CONSISTENT_PTE_INDEX(c->vm_start);
-		int i = 0;
-		u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
-
-		pte = consistent_pte[idx] + off;
-		c->priv = pages;
-
-		do {
-			BUG_ON(!pte_none(*pte));
-
-			set_pte_ext(pte, mk_pte(pages[i], prot), 0);
-			pte++;
-			off++;
-			i++;
-			if (off >= PTRS_PER_PTE) {
-				off = 0;
-				pte = consistent_pte[++idx];
-			}
-		} while (i < count);
 
-		dsb();
+	area->pages = pages;
+	area->nr_pages = nr_pages;
+	p = (unsigned long)area->addr;
 
-		return (void *)c->vm_start;
+	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 NULL;
 }
 
@@ -1230,6 +1090,19 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si
 	return 0;
 }
 
+static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
+{
+	struct vm_struct *area;
+
+	if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs))
+		return cpu_addr;
+
+	area = find_vm_area(cpu_addr);
+	if (area && (area->flags & VM_ARM_DMA_CONSISTENT))
+		return area->pages;
+	return NULL;
+}
+
 static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	    dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
 {
@@ -1248,7 +1121,11 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
 	if (*handle == DMA_ERROR_CODE)
 		goto err_buffer;
 
-	addr = __iommu_alloc_remap(pages, size, gfp, prot);
+	if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs))
+		return pages;
+
+	addr = __iommu_alloc_remap(pages, size, gfp, prot,
+				   __builtin_return_address(0));
 	if (!addr)
 		goto err_mapping;
 
@@ -1265,31 +1142,25 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 		    void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		    struct dma_attrs *attrs)
 {
-	struct arm_vmregion *c;
+	unsigned long uaddr = vma->vm_start;
+	unsigned long usize = vma->vm_end - vma->vm_start;
+	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
 
 	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
-	c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
-
-	if (c) {
-		struct page **pages = c->priv;
-
-		unsigned long uaddr = vma->vm_start;
-		unsigned long usize = vma->vm_end - vma->vm_start;
-		int i = 0;
 
-		do {
-			int ret;
+	if (!pages)
+		return -ENXIO;
 
-			ret = vm_insert_page(vma, uaddr, pages[i++]);
-			if (ret) {
-				pr_err("Remapping memory, error: %d\n", ret);
-				return ret;
-			}
+	do {
+		int ret = vm_insert_page(vma, uaddr, *pages++);
+		if (ret) {
+			pr_err("Remapping memory failed: %d\n", ret);
+			return ret;
+		}
+		uaddr += PAGE_SIZE;
+		usize -= PAGE_SIZE;
+	} while (usize > 0);
 
-			uaddr += PAGE_SIZE;
-			usize -= PAGE_SIZE;
-		} while (usize > 0);
-	}
 	return 0;
 }
 
@@ -1300,16 +1171,35 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 			  dma_addr_t handle, struct dma_attrs *attrs)
 {
-	struct arm_vmregion *c;
+	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
 	size = PAGE_ALIGN(size);
 
-	c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
-	if (c) {
-		struct page **pages = c->priv;
-		__dma_free_remap(cpu_addr, size);
-		__iommu_remove_mapping(dev, handle, size);
-		__iommu_free_buffer(dev, pages, size);
+	if (!pages) {
+		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
+		return;
 	}
+
+	if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) {
+		unmap_kernel_range((unsigned long)cpu_addr, size);
+		vunmap(cpu_addr);
+	}
+
+	__iommu_remove_mapping(dev, handle, size);
+	__iommu_free_buffer(dev, pages, size);
+}
+
+static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
+				 void *cpu_addr, dma_addr_t dma_addr,
+				 size_t size, struct dma_attrs *attrs)
+{
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
+
+	if (!pages)
+		return -ENXIO;
+
+	return sg_alloc_table_from_pages(sgt, pages, count, 0, size,
+					 GFP_KERNEL);
 }
 
 /*
@@ -1317,7 +1207,7 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
  */
 static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 			  size_t size, dma_addr_t *handle,
-			  enum dma_data_direction dir)
+			  enum dma_data_direction dir, struct dma_attrs *attrs)
 {
 	struct dma_iommu_mapping *mapping = dev->archdata.mapping;
 	dma_addr_t iova, iova_base;
@@ -1336,7 +1226,8 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 		phys_addr_t phys = page_to_phys(sg_page(s));
 		unsigned int len = PAGE_ALIGN(s->offset + s->length);
 
-		if (!arch_is_coherent())
+		if (!arch_is_coherent() &&
+		    !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
 			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
 
 		ret = iommu_map(mapping->domain, iova, phys, len, 0);
@@ -1383,7 +1274,7 @@ int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 
 		if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
 			if (__map_sg_chunk(dev, start, size, &dma->dma_address,
-			    dir) < 0)
+			    dir, attrs) < 0)
 				goto bad_mapping;
 
 			dma->dma_address += offset;
@@ -1396,7 +1287,7 @@ int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		}
 		size += s->length;
 	}
-	if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0)
+	if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs) < 0)
 		goto bad_mapping;
 
 	dma->dma_address += offset;
@@ -1430,7 +1321,8 @@ void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 		if (sg_dma_len(s))
 			__iommu_remove_mapping(dev, sg_dma_address(s),
 					       sg_dma_len(s));
-		if (!arch_is_coherent())
+		if (!arch_is_coherent() &&
+		    !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
 			__dma_page_dev_to_cpu(sg_page(s), s->offset,
 					      s->length, dir);
 	}
@@ -1492,7 +1384,7 @@ static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
 	dma_addr_t dma_addr;
 	int ret, len = PAGE_ALIGN(size + offset);
 
-	if (!arch_is_coherent())
+	if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
 		__dma_page_cpu_to_dev(page, offset, size, dir);
 
 	dma_addr = __alloc_iova(mapping, len);
@@ -1531,7 +1423,7 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
 	if (!iova)
 		return;
 
-	if (!arch_is_coherent())
+	if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
 		__dma_page_dev_to_cpu(page, offset, size, dir);
 
 	iommu_unmap(mapping->domain, iova, len);
@@ -1571,6 +1463,7 @@ struct dma_map_ops iommu_ops = {
 	.alloc		= arm_iommu_alloc_attrs,
 	.free		= arm_iommu_free_attrs,
 	.mmap		= arm_iommu_mmap_attrs,
+	.get_sgtable	= arm_iommu_get_sgtable,
 
 	.map_page		= arm_iommu_map_page,
 	.unmap_page		= arm_iommu_unmap_page,
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 77458548e031..40ca11ed6e5f 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -231,8 +231,6 @@ void __sync_icache_dcache(pte_t pteval)
 	struct page *page;
 	struct address_space *mapping;
 
-	if (!pte_present_user(pteval))
-		return;
 	if (cache_is_vipt_nonaliasing() && !pte_exec(pteval))
 		/* only flush non-aliasing VIPT caches for exec mappings */
 		return;
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index f54d59219764..9aec41fa80ae 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -21,13 +21,13 @@
 #include <linux/gfp.h>
 #include <linux/memblock.h>
 #include <linux/dma-contiguous.h>
+#include <linux/sizes.h>
 
 #include <asm/mach-types.h>
 #include <asm/memblock.h>
 #include <asm/prom.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
-#include <asm/sizes.h>
 #include <asm/tlb.h>
 #include <asm/fixmap.h>
 
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 8727802f8661..9d869f93a3da 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -25,6 +25,7 @@
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 #include <linux/io.h>
+#include <linux/sizes.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
@@ -32,7 +33,6 @@
 #include <asm/mmu_context.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
-#include <asm/sizes.h>
 #include <asm/system_info.h>
 
 #include <asm/mach/map.h>
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 2e8a1efdf7b8..a8ee92da3544 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -55,10 +55,16 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page
 /* permanent static mappings from iotable_init() */
 #define VM_ARM_STATIC_MAPPING	0x40000000
 
+/* empty mapping */
+#define VM_ARM_EMPTY_MAPPING	0x20000000
+
 /* mapping type (attributes) for permanent static mappings */
 #define VM_ARM_MTYPE(mt)		((mt) << 20)
 #define VM_ARM_MTYPE_MASK	(0x1f << 20)
 
+/* consistent regions used by dma_alloc_attrs() */
+#define VM_ARM_DMA_CONSISTENT	0x20000000
+
 #endif
 
 #ifdef CONFIG_ZONE_DMA
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 714a7fd99ca3..a7a9e41fa2c2 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -16,13 +16,13 @@
 #include <linux/memblock.h>
 #include <linux/fs.h>
 #include <linux/vmalloc.h>
+#include <linux/sizes.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
 #include <asm/sections.h>
 #include <asm/cachetype.h>
 #include <asm/setup.h>
-#include <asm/sizes.h>
 #include <asm/smp_plat.h>
 #include <asm/tlb.h>
 #include <asm/highmem.h>
@@ -423,12 +423,6 @@ static void __init build_mem_type_table(void)
 	vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
 
 	/*
-	 * Only use write-through for non-SMP systems
-	 */
-	if (!is_smp() && cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH)
-		vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte;
-
-	/*
 	 * Enable CPU-specific coherency if supported.
 	 * (Only available on XSC3 at the moment.)
 	 */
@@ -800,7 +794,7 @@ void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
 	vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
 	vm->addr = (void *)addr;
 	vm->size = size;
-	vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+	vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
 	vm->caller = caller;
 	vm_area_add_early(vm);
 }
@@ -833,7 +827,7 @@ static void __init fill_pmd_gaps(void)
 
 	/* we're still single threaded hence no lock needed here */
 	for (vm = vmlist; vm; vm = vm->next) {
-		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
+		if (!(vm->flags & (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING)))
 			continue;
 		addr = (unsigned long)vm->addr;
 		if (addr < next)
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 5900cd520e84..86b8b480634f 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -107,6 +107,12 @@ ENTRY(cpu_v6_switch_mm)
 	mcr	p15, 0, r2, c7, c5, 6		@ flush BTAC/BTB
 	mcr	p15, 0, r2, c7, c10, 4		@ drain write buffer
 	mcr	p15, 0, r0, c2, c0, 0		@ set TTB 0
+#ifdef CONFIG_PID_IN_CONTEXTIDR
+	mrc	p15, 0, r2, c13, c0, 1		@ read current context ID
+	bic	r2, r2, #0xff			@ extract the PID
+	and	r1, r1, #0xff
+	orr	r1, r1, r2			@ insert into new context ID
+#endif
 	mcr	p15, 0, r1, c13, c0, 1		@ set context ID
 #endif
 	mov	pc, lr
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index 42ac069c8012..fd045e706390 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -46,6 +46,11 @@ ENTRY(cpu_v7_switch_mm)
 #ifdef CONFIG_ARM_ERRATA_430973
 	mcr	p15, 0, r2, c7, c5, 6		@ flush BTAC/BTB
 #endif
+#ifdef CONFIG_PID_IN_CONTEXTIDR
+	mrc	p15, 0, r2, c13, c0, 1		@ read current context ID
+	lsr	r2, r2, #8			@ extract the PID
+	bfi	r1, r2, #8, #24			@ insert into new context ID
+#endif
 #ifdef CONFIG_ARM_ERRATA_754322
 	dsb
 #endif
diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
index 845f461f8ec1..ea94765acf9a 100644
--- a/arch/arm/mm/tlb-v7.S
+++ b/arch/arm/mm/tlb-v7.S
@@ -39,10 +39,18 @@ ENTRY(v7wbi_flush_user_tlb_range)
 	mov	r0, r0, lsr #PAGE_SHIFT		@ align address
 	mov	r1, r1, lsr #PAGE_SHIFT
 	asid	r3, r3				@ mask ASID
+#ifdef CONFIG_ARM_ERRATA_720789
+	ALT_SMP(W(mov)	r3, #0	)
+	ALT_UP(W(nop)		)
+#endif
 	orr	r0, r3, r0, lsl #PAGE_SHIFT	@ Create initial MVA
 	mov	r1, r1, lsl #PAGE_SHIFT
 1:
+#ifdef CONFIG_ARM_ERRATA_720789
+	ALT_SMP(mcr	p15, 0, r0, c8, c3, 3)	@ TLB invalidate U MVA all ASID (shareable)
+#else
 	ALT_SMP(mcr	p15, 0, r0, c8, c3, 1)	@ TLB invalidate U MVA (shareable)
+#endif
 	ALT_UP(mcr	p15, 0, r0, c8, c7, 1)	@ TLB invalidate U MVA
 
 	add	r0, r0, #PAGE_SZ
@@ -67,7 +75,11 @@ ENTRY(v7wbi_flush_kern_tlb_range)
 	mov	r0, r0, lsl #PAGE_SHIFT
 	mov	r1, r1, lsl #PAGE_SHIFT
 1:
+#ifdef CONFIG_ARM_ERRATA_720789
+	ALT_SMP(mcr	p15, 0, r0, c8, c3, 3)	@ TLB invalidate U MVA all ASID (shareable)
+#else
 	ALT_SMP(mcr	p15, 0, r0, c8, c3, 1)	@ TLB invalidate U MVA (shareable)
+#endif
 	ALT_UP(mcr	p15, 0, r0, c8, c7, 1)	@ TLB invalidate U MVA
 	add	r0, r0, #PAGE_SZ
 	cmp	r0, r1