arch/s390/pci/pci_dma.c - linux - Git at Google

 /*
  * Copyright IBM Corp. 2012
  *
  * Author(s):
  *   Jan Glauber <jang@linux.vnet.ibm.com>
  */

 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <linux/iommu-helper.h>
 #include <linux/dma-mapping.h>
 #include <linux/pci.h>
 #include <asm/pci_dma.h>

 static struct kmem_cache *dma_region_table_cache;
 static struct kmem_cache *dma_page_table_cache;

 static unsigned long *dma_alloc_cpu_table(void)
 {
 	unsigned long *table, *entry;

 	table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
 	if (!table)
 		return NULL;

 	for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
 		*entry = ZPCI_TABLE_INVALID | ZPCI_TABLE_PROTECTED;
 	return table;
 }

 static void dma_free_cpu_table(void *table)
 {
 	kmem_cache_free(dma_region_table_cache, table);
 }

 static unsigned long *dma_alloc_page_table(void)
 {
 	unsigned long *table, *entry;

 	table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
 	if (!table)
 		return NULL;

 	for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
 		*entry = ZPCI_PTE_INVALID | ZPCI_TABLE_PROTECTED;
 	return table;
 }

 static void dma_free_page_table(void *table)
 {
 	kmem_cache_free(dma_page_table_cache, table);
 }

 static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
 {
 	unsigned long *sto;

 	if (reg_entry_isvalid(*entry))
 		sto = get_rt_sto(*entry);
 	else {
 		sto = dma_alloc_cpu_table();
 		if (!sto)
 			return NULL;

 		set_rt_sto(entry, sto);
 		validate_rt_entry(entry);
 		entry_clr_protected(entry);
 	}
 	return sto;
 }

 static unsigned long *dma_get_page_table_origin(unsigned long *entry)
 {
 	unsigned long *pto;

 	if (reg_entry_isvalid(*entry))
 		pto = get_st_pto(*entry);
 	else {
 		pto = dma_alloc_page_table();
 		if (!pto)
 			return NULL;
 		set_st_pto(entry, pto);
 		validate_st_entry(entry);
 		entry_clr_protected(entry);
 	}
 	return pto;
 }

 static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
 {
 	unsigned long *sto, *pto;
 	unsigned int rtx, sx, px;

 	rtx = calc_rtx(dma_addr);
 	sto = dma_get_seg_table_origin(&rto[rtx]);
 	if (!sto)
 		return NULL;

 	sx = calc_sx(dma_addr);
 	pto = dma_get_page_table_origin(&sto[sx]);
 	if (!pto)
 		return NULL;

 	px = calc_px(dma_addr);
 	return &pto[px];
 }

 static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
 				 dma_addr_t dma_addr, int flags)
 {
 	unsigned long *entry;

 	entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
 	if (!entry) {
 		WARN_ON_ONCE(1);
 		return;
 	}

 	if (flags & ZPCI_PTE_INVALID) {
 		invalidate_pt_entry(entry);
 		return;
 	} else {
 		set_pt_pfaa(entry, page_addr);
 		validate_pt_entry(entry);
 	}

 	if (flags & ZPCI_TABLE_PROTECTED)
 		entry_set_protected(entry);
 	else
 		entry_clr_protected(entry);
 }

 static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 			    dma_addr_t dma_addr, size_t size, int flags)
 {
 	unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	u8 *page_addr = (u8 *) (pa & PAGE_MASK);
 	dma_addr_t start_dma_addr = dma_addr;
 	unsigned long irq_flags;
 	int i, rc = 0;

 	if (!nr_pages)
 		return -EINVAL;

 	spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
 	if (!zdev->dma_table) {
 		dev_err(&zdev->pdev->dev, "Missing DMA table\n");
 		goto no_refresh;
 	}

 	for (i = 0; i < nr_pages; i++) {
 		dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
 		page_addr += PAGE_SIZE;
 		dma_addr += PAGE_SIZE;
 	}

 	/*
 	 * rpcit is not required to establish new translations when previously
 	 * invalid translation-table entries are validated, however it is
 	 * required when altering previously valid entries.
 	 */
 	if (!zdev->tlb_refresh &&
 	    ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
 		/*
 		 * TODO: also need to check that the old entry is indeed INVALID
 		 * and not only for one page but for the whole range...
 		 * -> now we WARN_ON in that case but with lazy unmap that
 		 * needs to be redone!
 		 */
 		goto no_refresh;
 	rc = rpcit_instr((u64) zdev->fh << 32, start_dma_addr,
 			  nr_pages * PAGE_SIZE);

 no_refresh:
 	spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
 	return rc;
 }

 static void dma_free_seg_table(unsigned long entry)
 {
 	unsigned long *sto = get_rt_sto(entry);
 	int sx;

 	for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
 		if (reg_entry_isvalid(sto[sx]))
 			dma_free_page_table(get_st_pto(sto[sx]));

 	dma_free_cpu_table(sto);
 }

 static void dma_cleanup_tables(struct zpci_dev *zdev)
 {
 	unsigned long *table;
 	int rtx;

 	if (!zdev || !zdev->dma_table)
 		return;

 	table = zdev->dma_table;
 	for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
 		if (reg_entry_isvalid(table[rtx]))
 			dma_free_seg_table(table[rtx]);

 	dma_free_cpu_table(table);
 	zdev->dma_table = NULL;
 }

 static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, unsigned long start,
 				   int size)
 {
 	unsigned long boundary_size = 0x1000000;

 	return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
 				start, size, 0, boundary_size, 0);
 }

 static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
 {
 	unsigned long offset, flags;

 	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 	offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
 	if (offset == -1)
 		offset = __dma_alloc_iommu(zdev, 0, size);

 	if (offset != -1) {
 		zdev->next_bit = offset + size;
 		if (zdev->next_bit >= zdev->iommu_pages)
 			zdev->next_bit = 0;
 	}
 	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 	return offset;
 }

 static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 	if (!zdev->iommu_bitmap)
 		goto out;
 	bitmap_clear(zdev->iommu_bitmap, offset, size);
 	if (offset >= zdev->next_bit)
 		zdev->next_bit = offset + size;
 out:
 	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 }

 int dma_set_mask(struct device *dev, u64 mask)
 {
 	if (!dev->dma_mask || !dma_supported(dev, mask))
 		return -EIO;

 	*dev->dma_mask = mask;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(dma_set_mask);

 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
 				     unsigned long offset, size_t size,
 				     enum dma_data_direction direction,
 				     struct dma_attrs *attrs)
 {
 	struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 	unsigned long nr_pages, iommu_page_index;
 	unsigned long pa = page_to_phys(page) + offset;
 	int flags = ZPCI_PTE_VALID;
 	dma_addr_t dma_addr;

 	WARN_ON_ONCE(offset > PAGE_SIZE);

 	/* This rounds up number of pages based on size and offset */
 	nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
 	iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
 	if (iommu_page_index == -1)
 		goto out_err;

 	/* Use rounded up size */
 	size = nr_pages * PAGE_SIZE;

 	dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
 	if (dma_addr + size > zdev->end_dma) {
 		dev_err(dev, "(dma_addr: 0x%16.16LX + size: 0x%16.16lx) > end_dma: 0x%16.16Lx\n",
 			 dma_addr, size, zdev->end_dma);
 		goto out_free;
 	}

 	if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
 		flags |= ZPCI_TABLE_PROTECTED;

 	if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
 		atomic64_add(nr_pages, (atomic64_t *) &zdev->fmb->mapped_pages);
 		return dma_addr + offset;
 	}

 out_free:
 	dma_free_iommu(zdev, iommu_page_index, nr_pages);
 out_err:
 	dev_err(dev, "Failed to map addr: %lx\n", pa);
 	return DMA_ERROR_CODE;
 }

 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
 				 size_t size, enum dma_data_direction direction,
 				 struct dma_attrs *attrs)
 {
 	struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 	unsigned long iommu_page_index;
 	int npages;

 	npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
 	dma_addr = dma_addr & PAGE_MASK;
 	if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
 			     ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID))
 		dev_err(dev, "Failed to unmap addr: %Lx\n", dma_addr);

 	atomic64_add(npages, (atomic64_t *) &zdev->fmb->unmapped_pages);
 	iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
 	dma_free_iommu(zdev, iommu_page_index, npages);
 }

 static void *s390_dma_alloc(struct device *dev, size_t size,
 			    dma_addr_t *dma_handle, gfp_t flag,
 			    struct dma_attrs *attrs)
 {
 	struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
 	struct page *page;
 	unsigned long pa;
 	dma_addr_t map;

 	size = PAGE_ALIGN(size);
 	page = alloc_pages(flag, get_order(size));
 	if (!page)
 		return NULL;

 	atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages);
 	pa = page_to_phys(page);
 	memset((void *) pa, 0, size);

 	map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
 				 size, DMA_BIDIRECTIONAL, NULL);
 	if (dma_mapping_error(dev, map)) {
 		free_pages(pa, get_order(size));
 		return NULL;
 	}

 	if (dma_handle)
 		*dma_handle = map;
 	return (void *) pa;
 }

 static void s390_dma_free(struct device *dev, size_t size,
 			  void *pa, dma_addr_t dma_handle,
 			  struct dma_attrs *attrs)
 {
 	s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(size),
 			     DMA_BIDIRECTIONAL, NULL);
 	free_pages((unsigned long) pa, get_order(size));
 }

 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 			   int nr_elements, enum dma_data_direction dir,
 			   struct dma_attrs *attrs)
 {
 	int mapped_elements = 0;
 	struct scatterlist *s;
 	int i;

 	for_each_sg(sg, s, nr_elements, i) {
 		struct page *page = sg_page(s);
 		s->dma_address = s390_dma_map_pages(dev, page, s->offset,
 						    s->length, dir, NULL);
 		if (!dma_mapping_error(dev, s->dma_address)) {
 			s->dma_length = s->length;
 			mapped_elements++;
 		} else
 			goto unmap;
 	}
 out:
 	return mapped_elements;

 unmap:
 	for_each_sg(sg, s, mapped_elements, i) {
 		if (s->dma_address)
 			s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
 					     dir, NULL);
 		s->dma_address = 0;
 		s->dma_length = 0;
 	}
 	mapped_elements = 0;
 	goto out;
 }

 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 			      int nr_elements, enum dma_data_direction dir,
 			      struct dma_attrs *attrs)
 {
 	struct scatterlist *s;
 	int i;

 	for_each_sg(sg, s, nr_elements, i) {
 		s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
 		s->dma_address = 0;
 		s->dma_length = 0;
 	}
 }

 int zpci_dma_init_device(struct zpci_dev *zdev)
 {
 	unsigned int bitmap_order;
 	int rc;

 	spin_lock_init(&zdev->iommu_bitmap_lock);
 	spin_lock_init(&zdev->dma_table_lock);

 	zdev->dma_table = dma_alloc_cpu_table();
 	if (!zdev->dma_table) {
 		rc = -ENOMEM;
 		goto out_clean;
 	}

 	zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
 	zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
 	bitmap_order = get_order(zdev->iommu_pages / 8);
 	pr_info("iommu_size: 0x%lx  iommu_pages: 0x%lx  bitmap_order: %i\n",
 		 zdev->iommu_size, zdev->iommu_pages, bitmap_order);

 	zdev->iommu_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
 						       bitmap_order);
 	if (!zdev->iommu_bitmap) {
 		rc = -ENOMEM;
 		goto out_reg;
 	}

 	rc = zpci_register_ioat(zdev,
 				0,
 				zdev->start_dma + PAGE_OFFSET,
 				zdev->start_dma + zdev->iommu_size - 1,
 				(u64) zdev->dma_table);
 	if (rc)
 		goto out_reg;
 	return 0;

 out_reg:
 	dma_free_cpu_table(zdev->dma_table);
 out_clean:
 	return rc;
 }

 void zpci_dma_exit_device(struct zpci_dev *zdev)
 {
 	zpci_unregister_ioat(zdev, 0);
 	dma_cleanup_tables(zdev);
 	free_pages((unsigned long) zdev->iommu_bitmap,
 		   get_order(zdev->iommu_pages / 8));
 	zdev->iommu_bitmap = NULL;
 	zdev->next_bit = 0;
 }

 static int __init dma_alloc_cpu_table_caches(void)
 {
 	dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 					ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 					0, NULL);
 	if (!dma_region_table_cache)
 		return -ENOMEM;

 	dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 					ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 					0, NULL);
 	if (!dma_page_table_cache) {
 		kmem_cache_destroy(dma_region_table_cache);
 		return -ENOMEM;
 	}
 	return 0;
 }

 int __init zpci_dma_init(void)
 {
 	return dma_alloc_cpu_table_caches();
 }

 void zpci_dma_exit(void)
 {
 	kmem_cache_destroy(dma_page_table_cache);
 	kmem_cache_destroy(dma_region_table_cache);
 }

 #define PREALLOC_DMA_DEBUG_ENTRIES	(1 << 16)

 static int __init dma_debug_do_init(void)
 {
 	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 	return 0;
 }
 fs_initcall(dma_debug_do_init);

 struct dma_map_ops s390_dma_ops = {
 	.alloc		= s390_dma_alloc,
 	.free		= s390_dma_free,
 	.map_sg		= s390_dma_map_sg,
 	.unmap_sg	= s390_dma_unmap_sg,
 	.map_page	= s390_dma_map_pages,
 	.unmap_page	= s390_dma_unmap_pages,
 	/* if we support direct DMA this must be conditional */
 	.is_phys	= 0,
 	/* dma_supported is unconditionally true without a callback */
 };
 EXPORT_SYMBOL_GPL(s390_dma_ops);
	/*
	* Copyright IBM Corp. 2012
	*
	* Author(s):
	* Jan Glauber <jang@linux.vnet.ibm.com>
	*/

	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/export.h>
	#include <linux/iommu-helper.h>
	#include <linux/dma-mapping.h>
	#include <linux/pci.h>
	#include <asm/pci_dma.h>

	static struct kmem_cache *dma_region_table_cache;
	static struct kmem_cache *dma_page_table_cache;

	static unsigned long *dma_alloc_cpu_table(void)
	{
	unsigned long table, entry;

	table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
	if (!table)
	return NULL;

	for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
	*entry = ZPCI_TABLE_INVALID \| ZPCI_TABLE_PROTECTED;
	return table;
	}

	static void dma_free_cpu_table(void *table)
	{
	kmem_cache_free(dma_region_table_cache, table);
	}

	static unsigned long *dma_alloc_page_table(void)
	{
	unsigned long table, entry;

	table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
	if (!table)
	return NULL;

	for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
	*entry = ZPCI_PTE_INVALID \| ZPCI_TABLE_PROTECTED;
	return table;
	}

	static void dma_free_page_table(void *table)
	{
	kmem_cache_free(dma_page_table_cache, table);
	}

	static unsigned long dma_get_seg_table_origin(unsigned long entry)
	{
	unsigned long *sto;

	if (reg_entry_isvalid(*entry))
	sto = get_rt_sto(*entry);
	else {
	sto = dma_alloc_cpu_table();
	if (!sto)
	return NULL;

	set_rt_sto(entry, sto);
	validate_rt_entry(entry);
	entry_clr_protected(entry);
	}
	return sto;
	}

	static unsigned long dma_get_page_table_origin(unsigned long entry)
	{
	unsigned long *pto;

	if (reg_entry_isvalid(*entry))
	pto = get_st_pto(*entry);
	else {
	pto = dma_alloc_page_table();
	if (!pto)
	return NULL;
	set_st_pto(entry, pto);
	validate_st_entry(entry);
	entry_clr_protected(entry);
	}
	return pto;
	}

	static unsigned long dma_walk_cpu_trans(unsigned long rto, dma_addr_t dma_addr)
	{
	unsigned long sto, pto;
	unsigned int rtx, sx, px;

	rtx = calc_rtx(dma_addr);
	sto = dma_get_seg_table_origin(&rto[rtx]);
	if (!sto)
	return NULL;

	sx = calc_sx(dma_addr);
	pto = dma_get_page_table_origin(&sto[sx]);
	if (!pto)
	return NULL;

	px = calc_px(dma_addr);
	return &pto[px];
	}

	static void dma_update_cpu_trans(struct zpci_dev zdev, void page_addr,
	dma_addr_t dma_addr, int flags)
	{
	unsigned long *entry;

	entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
	if (!entry) {
	WARN_ON_ONCE(1);
	return;
	}

	if (flags & ZPCI_PTE_INVALID) {
	invalidate_pt_entry(entry);
	return;
	} else {
	set_pt_pfaa(entry, page_addr);
	validate_pt_entry(entry);
	}

	if (flags & ZPCI_TABLE_PROTECTED)
	entry_set_protected(entry);
	else
	entry_clr_protected(entry);
	}

	static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
	dma_addr_t dma_addr, size_t size, int flags)
	{
	unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
	u8 page_addr = (u8 ) (pa & PAGE_MASK);
	dma_addr_t start_dma_addr = dma_addr;
	unsigned long irq_flags;
	int i, rc = 0;

	if (!nr_pages)
	return -EINVAL;

	spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
	if (!zdev->dma_table) {
	dev_err(&zdev->pdev->dev, "Missing DMA table\n");
	goto no_refresh;
	}

	for (i = 0; i < nr_pages; i++) {
	dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
	page_addr += PAGE_SIZE;
	dma_addr += PAGE_SIZE;
	}

	/*
	* rpcit is not required to establish new translations when previously
	* invalid translation-table entries are validated, however it is
	* required when altering previously valid entries.
	*/
	if (!zdev->tlb_refresh &&
	((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
	/*
	* TODO: also need to check that the old entry is indeed INVALID
	* and not only for one page but for the whole range...
	* -> now we WARN_ON in that case but with lazy unmap that
	* needs to be redone!
	*/
	goto no_refresh;
	rc = rpcit_instr((u64) zdev->fh << 32, start_dma_addr,
	nr_pages * PAGE_SIZE);

	no_refresh:
	spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
	return rc;
	}

	static void dma_free_seg_table(unsigned long entry)
	{
	unsigned long *sto = get_rt_sto(entry);
	int sx;

	for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
	if (reg_entry_isvalid(sto[sx]))
	dma_free_page_table(get_st_pto(sto[sx]));

	dma_free_cpu_table(sto);
	}

	static void dma_cleanup_tables(struct zpci_dev *zdev)
	{
	unsigned long *table;
	int rtx;

	if (!zdev \|\| !zdev->dma_table)
	return;

	table = zdev->dma_table;
	for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
	if (reg_entry_isvalid(table[rtx]))
	dma_free_seg_table(table[rtx]);

	dma_free_cpu_table(table);
	zdev->dma_table = NULL;
	}

	static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev, unsigned long start,
	int size)
	{
	unsigned long boundary_size = 0x1000000;

	return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
	start, size, 0, boundary_size, 0);
	}

	static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
	{
	unsigned long offset, flags;

	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
	offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
	if (offset == -1)
	offset = __dma_alloc_iommu(zdev, 0, size);

	if (offset != -1) {
	zdev->next_bit = offset + size;
	if (zdev->next_bit >= zdev->iommu_pages)
	zdev->next_bit = 0;
	}
	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
	return offset;
	}

	static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
	{
	unsigned long flags;

	spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
	if (!zdev->iommu_bitmap)
	goto out;
	bitmap_clear(zdev->iommu_bitmap, offset, size);
	if (offset >= zdev->next_bit)
	zdev->next_bit = offset + size;
	out:
	spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
	}

	int dma_set_mask(struct device *dev, u64 mask)
	{
	if (!dev->dma_mask \|\| !dma_supported(dev, mask))
	return -EIO;

	*dev->dma_mask = mask;
	return 0;
	}
	EXPORT_SYMBOL_GPL(dma_set_mask);

	static dma_addr_t s390_dma_map_pages(struct device dev, struct page page,
	unsigned long offset, size_t size,
	enum dma_data_direction direction,
	struct dma_attrs *attrs)
	{
	struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
	unsigned long nr_pages, iommu_page_index;
	unsigned long pa = page_to_phys(page) + offset;
	int flags = ZPCI_PTE_VALID;
	dma_addr_t dma_addr;

	WARN_ON_ONCE(offset > PAGE_SIZE);

	/* This rounds up number of pages based on size and offset */
	nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
	iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
	if (iommu_page_index == -1)
	goto out_err;

	/* Use rounded up size */
	size = nr_pages * PAGE_SIZE;

	dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
	if (dma_addr + size > zdev->end_dma) {
	dev_err(dev, "(dma_addr: 0x%16.16LX + size: 0x%16.16lx) > end_dma: 0x%16.16Lx\n",
	dma_addr, size, zdev->end_dma);
	goto out_free;
	}

	if (direction == DMA_NONE \|\| direction == DMA_TO_DEVICE)
	flags \|= ZPCI_TABLE_PROTECTED;

	if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
	atomic64_add(nr_pages, (atomic64_t *) &zdev->fmb->mapped_pages);
	return dma_addr + offset;
	}

	out_free:
	dma_free_iommu(zdev, iommu_page_index, nr_pages);
	out_err:
	dev_err(dev, "Failed to map addr: %lx\n", pa);
	return DMA_ERROR_CODE;
	}

	static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
	size_t size, enum dma_data_direction direction,
	struct dma_attrs *attrs)
	{
	struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
	unsigned long iommu_page_index;
	int npages;

	npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
	dma_addr = dma_addr & PAGE_MASK;
	if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
	ZPCI_TABLE_PROTECTED \| ZPCI_PTE_INVALID))
	dev_err(dev, "Failed to unmap addr: %Lx\n", dma_addr);

	atomic64_add(npages, (atomic64_t *) &zdev->fmb->unmapped_pages);
	iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
	dma_free_iommu(zdev, iommu_page_index, npages);
	}

	static void s390_dma_alloc(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t flag,
	struct dma_attrs *attrs)
	{
	struct zpci_dev *zdev = get_zdev(container_of(dev, struct pci_dev, dev));
	struct page *page;
	unsigned long pa;
	dma_addr_t map;

	size = PAGE_ALIGN(size);
	page = alloc_pages(flag, get_order(size));
	if (!page)
	return NULL;

	atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages);
	pa = page_to_phys(page);
	memset((void *) pa, 0, size);

	map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
	size, DMA_BIDIRECTIONAL, NULL);
	if (dma_mapping_error(dev, map)) {
	free_pages(pa, get_order(size));
	return NULL;
	}

	if (dma_handle)
	*dma_handle = map;
	return (void *) pa;
	}

	static void s390_dma_free(struct device *dev, size_t size,
	void *pa, dma_addr_t dma_handle,
	struct dma_attrs *attrs)
	{
	s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(size),
	DMA_BIDIRECTIONAL, NULL);
	free_pages((unsigned long) pa, get_order(size));
	}

	static int s390_dma_map_sg(struct device dev, struct scatterlist sg,
	int nr_elements, enum dma_data_direction dir,
	struct dma_attrs *attrs)
	{
	int mapped_elements = 0;
	struct scatterlist *s;
	int i;

	for_each_sg(sg, s, nr_elements, i) {
	struct page *page = sg_page(s);
	s->dma_address = s390_dma_map_pages(dev, page, s->offset,
	s->length, dir, NULL);
	if (!dma_mapping_error(dev, s->dma_address)) {
	s->dma_length = s->length;
	mapped_elements++;
	} else
	goto unmap;
	}
	out:
	return mapped_elements;

	unmap:
	for_each_sg(sg, s, mapped_elements, i) {
	if (s->dma_address)
	s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
	dir, NULL);
	s->dma_address = 0;
	s->dma_length = 0;
	}
	mapped_elements = 0;
	goto out;
	}

	static void s390_dma_unmap_sg(struct device dev, struct scatterlist sg,
	int nr_elements, enum dma_data_direction dir,
	struct dma_attrs *attrs)
	{
	struct scatterlist *s;
	int i;

	for_each_sg(sg, s, nr_elements, i) {
	s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
	s->dma_address = 0;
	s->dma_length = 0;
	}
	}

	int zpci_dma_init_device(struct zpci_dev *zdev)
	{
	unsigned int bitmap_order;
	int rc;

	spin_lock_init(&zdev->iommu_bitmap_lock);
	spin_lock_init(&zdev->dma_table_lock);

	zdev->dma_table = dma_alloc_cpu_table();
	if (!zdev->dma_table) {
	rc = -ENOMEM;
	goto out_clean;
	}

	zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
	zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
	bitmap_order = get_order(zdev->iommu_pages / 8);
	pr_info("iommu_size: 0x%lx iommu_pages: 0x%lx bitmap_order: %i\n",
	zdev->iommu_size, zdev->iommu_pages, bitmap_order);

	zdev->iommu_bitmap = (void *) __get_free_pages(GFP_KERNEL \| __GFP_ZERO,
	bitmap_order);
	if (!zdev->iommu_bitmap) {
	rc = -ENOMEM;
	goto out_reg;
	}

	rc = zpci_register_ioat(zdev,
	0,
	zdev->start_dma + PAGE_OFFSET,
	zdev->start_dma + zdev->iommu_size - 1,
	(u64) zdev->dma_table);
	if (rc)
	goto out_reg;
	return 0;

	out_reg:
	dma_free_cpu_table(zdev->dma_table);
	out_clean:
	return rc;
	}

	void zpci_dma_exit_device(struct zpci_dev *zdev)
	{
	zpci_unregister_ioat(zdev, 0);
	dma_cleanup_tables(zdev);
	free_pages((unsigned long) zdev->iommu_bitmap,
	get_order(zdev->iommu_pages / 8));
	zdev->iommu_bitmap = NULL;
	zdev->next_bit = 0;
	}

	static int __init dma_alloc_cpu_table_caches(void)
	{
	dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
	ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
	0, NULL);
	if (!dma_region_table_cache)
	return -ENOMEM;

	dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
	ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
	0, NULL);
	if (!dma_page_table_cache) {
	kmem_cache_destroy(dma_region_table_cache);
	return -ENOMEM;
	}
	return 0;
	}

	int __init zpci_dma_init(void)
	{
	return dma_alloc_cpu_table_caches();
	}

	void zpci_dma_exit(void)
	{
	kmem_cache_destroy(dma_page_table_cache);
	kmem_cache_destroy(dma_region_table_cache);
	}

	#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)

	static int __init dma_debug_do_init(void)
	{
	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
	return 0;
	}
	fs_initcall(dma_debug_do_init);

	struct dma_map_ops s390_dma_ops = {
	.alloc = s390_dma_alloc,
	.free = s390_dma_free,
	.map_sg = s390_dma_map_sg,
	.unmap_sg = s390_dma_unmap_sg,
	.map_page = s390_dma_map_pages,
	.unmap_page = s390_dma_unmap_pages,
	/* if we support direct DMA this must be conditional */
	.is_phys = 0,
	/* dma_supported is unconditionally true without a callback */
	};
	EXPORT_SYMBOL_GPL(s390_dma_ops);