[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/iommu/dma-iommu.c b/src/kernel/linux/v4.14/drivers/iommu/dma-iommu.c
new file mode 100644
index 0000000..5f5fc11
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/iommu/dma-iommu.c
@@ -0,0 +1,1046 @@
+/*
+ * A fairly generic DMA-API to IOMMU-API glue layer.
+ *
+ * Copyright (C) 2014-2015 ARM Ltd.
+ *
+ * based in part on arch/arm/mm/dma-mapping.c:
+ * Copyright (C) 2000-2004 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/dma-iommu.h>
+#include <linux/gfp.h>
+#include <linux/huge_mm.h>
+#include <linux/iommu.h>
+#include <linux/iova.h>
+#include <linux/irq.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+#include <linux/scatterlist.h>
+#include <linux/vmalloc.h>
+
+#define IOMMU_MAPPING_ERROR	0
+
+struct iommu_dma_msi_page {
+	struct list_head	list;
+	dma_addr_t		iova;
+	phys_addr_t		phys;
+};
+
+enum iommu_dma_cookie_type {
+	IOMMU_DMA_IOVA_COOKIE,
+	IOMMU_DMA_MSI_COOKIE,
+};
+
+struct iommu_dma_cookie {
+	enum iommu_dma_cookie_type	type;
+	union {
+		/* Full allocator for IOMMU_DMA_IOVA_COOKIE */
+		struct iova_domain	iovad;
+		/* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */
+		dma_addr_t		msi_iova;
+	};
+	struct list_head		msi_page_list;
+	spinlock_t			msi_lock;
+};
+
+static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
+{
+	if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
+		return cookie->iovad.granule;
+	return PAGE_SIZE;
+}
+
+static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
+{
+	struct iommu_dma_cookie *cookie;
+
+	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
+	if (cookie) {
+		spin_lock_init(&cookie->msi_lock);
+		INIT_LIST_HEAD(&cookie->msi_page_list);
+		cookie->type = type;
+	}
+	return cookie;
+}
+
+int iommu_dma_init(void)
+{
+	return iova_cache_get();
+}
+
+/**
+ * iommu_get_dma_cookie - Acquire DMA-API resources for a domain
+ * @domain: IOMMU domain to prepare for DMA-API usage
+ *
+ * IOMMU drivers should normally call this from their domain_alloc
+ * callback when domain->type == IOMMU_DOMAIN_DMA.
+ */
+int iommu_get_dma_cookie(struct iommu_domain *domain)
+{
+	if (domain->iova_cookie)
+		return -EEXIST;
+
+	domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE);
+	if (!domain->iova_cookie)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL(iommu_get_dma_cookie);
+
+/**
+ * iommu_get_msi_cookie - Acquire just MSI remapping resources
+ * @domain: IOMMU domain to prepare
+ * @base: Start address of IOVA region for MSI mappings
+ *
+ * Users who manage their own IOVA allocation and do not want DMA API support,
+ * but would still like to take advantage of automatic MSI remapping, can use
+ * this to initialise their own domain appropriately. Users should reserve a
+ * contiguous IOVA region, starting at @base, large enough to accommodate the
+ * number of PAGE_SIZE mappings necessary to cover every MSI doorbell address
+ * used by the devices attached to @domain.
+ */
+int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
+{
+	struct iommu_dma_cookie *cookie;
+
+	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+		return -EINVAL;
+
+	if (domain->iova_cookie)
+		return -EEXIST;
+
+	cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE);
+	if (!cookie)
+		return -ENOMEM;
+
+	cookie->msi_iova = base;
+	domain->iova_cookie = cookie;
+	return 0;
+}
+EXPORT_SYMBOL(iommu_get_msi_cookie);
+
+/**
+ * iommu_put_dma_cookie - Release a domain's DMA mapping resources
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() or
+ *          iommu_get_msi_cookie()
+ *
+ * IOMMU drivers should normally call this from their domain_free callback.
+ */
+void iommu_put_dma_cookie(struct iommu_domain *domain)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iommu_dma_msi_page *msi, *tmp;
+
+	if (!cookie)
+		return;
+
+	if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule)
+		put_iova_domain(&cookie->iovad);
+
+	list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) {
+		list_del(&msi->list);
+		kfree(msi);
+	}
+	kfree(cookie);
+	domain->iova_cookie = NULL;
+}
+EXPORT_SYMBOL(iommu_put_dma_cookie);
+
+/**
+ * iommu_dma_get_resv_regions - Reserved region driver helper
+ * @dev: Device from iommu_get_resv_regions()
+ * @list: Reserved region list from iommu_get_resv_regions()
+ *
+ * IOMMU drivers can use this to implement their .get_resv_regions callback
+ * for general non-IOMMU-specific reservations. Currently, this covers host
+ * bridge windows for PCI devices.
+ */
+void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
+{
+	struct pci_host_bridge *bridge;
+	struct resource_entry *window;
+
+	if (!dev_is_pci(dev))
+		return;
+
+	bridge = pci_find_host_bridge(to_pci_dev(dev)->bus);
+	resource_list_for_each_entry(window, &bridge->windows) {
+		struct iommu_resv_region *region;
+		phys_addr_t start;
+		size_t length;
+
+		if (resource_type(window->res) != IORESOURCE_MEM)
+			continue;
+
+		start = window->res->start - window->offset;
+		length = window->res->end - window->res->start + 1;
+		region = iommu_alloc_resv_region(start, length, 0,
+				IOMMU_RESV_RESERVED);
+		if (!region)
+			return;
+
+		list_add_tail(&region->list, list);
+	}
+}
+EXPORT_SYMBOL(iommu_dma_get_resv_regions);
+
+static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
+		phys_addr_t start, phys_addr_t end)
+{
+	struct iova_domain *iovad = &cookie->iovad;
+	struct iommu_dma_msi_page *msi_page;
+	int i, num_pages;
+
+	start -= iova_offset(iovad, start);
+	num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
+
+	for (i = 0; i < num_pages; i++) {
+		msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
+		if (!msi_page)
+			return -ENOMEM;
+
+		msi_page->phys = start;
+		msi_page->iova = start;
+		INIT_LIST_HEAD(&msi_page->list);
+		list_add(&msi_page->list, &cookie->msi_page_list);
+		start += iovad->granule;
+	}
+
+	return 0;
+}
+
+static int iova_reserve_iommu_regions(struct device *dev,
+		struct iommu_domain *domain)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct iommu_resv_region *region;
+	LIST_HEAD(resv_regions);
+	int ret = 0;
+
+	iommu_get_resv_regions(dev, &resv_regions);
+	list_for_each_entry(region, &resv_regions, list) {
+		unsigned long lo, hi;
+
+		/* We ARE the software that manages these! */
+		if (region->type == IOMMU_RESV_SW_MSI)
+			continue;
+
+		lo = iova_pfn(iovad, region->start);
+		hi = iova_pfn(iovad, region->start + region->length - 1);
+		reserve_iova(iovad, lo, hi);
+
+		if (region->type == IOMMU_RESV_MSI)
+			ret = cookie_init_hw_msi_region(cookie, region->start,
+					region->start + region->length);
+		if (ret)
+			break;
+	}
+	iommu_put_resv_regions(dev, &resv_regions);
+
+	return ret;
+}
+
+/**
+ * iommu_dma_init_domain - Initialise a DMA mapping domain
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
+ * @base: IOVA at which the mappable address space starts
+ * @size: Size of IOVA space
+ * @dev: Device the domain is being initialised for
+ *
+ * @base and @size should be exact multiples of IOMMU page granularity to
+ * avoid rounding surprises. If necessary, we reserve the page at address 0
+ * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but
+ * any change which could make prior IOVAs invalid will fail.
+ */
+int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
+		u64 size, struct device *dev)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	unsigned long order, base_pfn, end_pfn;
+
+	if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
+		return -EINVAL;
+
+	/* Use the smallest supported page size for IOVA granularity */
+	order = __ffs(domain->pgsize_bitmap);
+	base_pfn = max_t(unsigned long, 1, base >> order);
+	end_pfn = (base + size - 1) >> order;
+
+	/* Check the domain allows at least some access to the device... */
+	if (domain->geometry.force_aperture) {
+		if (base > domain->geometry.aperture_end ||
+		    base + size <= domain->geometry.aperture_start) {
+			pr_warn("specified DMA range outside IOMMU capability\n");
+			return -EFAULT;
+		}
+		/* ...then finally give it a kicking to make sure it fits */
+		base_pfn = max_t(unsigned long, base_pfn,
+				domain->geometry.aperture_start >> order);
+		end_pfn = min_t(unsigned long, end_pfn,
+				domain->geometry.aperture_end >> order);
+	}
+	/*
+	 * PCI devices may have larger DMA masks, but still prefer allocating
+	 * within a 32-bit mask to avoid DAC addressing. Such limitations don't
+	 * apply to the typical platform device, so for those we may as well
+	 * leave the cache limit at the top of their range to save an rb_last()
+	 * traversal on every allocation.
+	 */
+	if (dev && dev_is_pci(dev))
+		end_pfn &= DMA_BIT_MASK(32) >> order;
+
+	/* start_pfn is always nonzero for an already-initialised domain */
+	if (iovad->start_pfn) {
+		if (1UL << order != iovad->granule ||
+		    base_pfn != iovad->start_pfn) {
+			pr_warn("Incompatible range for DMA domain\n");
+			return -EFAULT;
+		}
+		/*
+		 * If we have devices with different DMA masks, move the free
+		 * area cache limit down for the benefit of the smaller one.
+		 */
+		iovad->dma_32bit_pfn = min(end_pfn + 1, iovad->dma_32bit_pfn);
+
+		return 0;
+	}
+
+	init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
+	if (!dev)
+		return 0;
+
+	return iova_reserve_iommu_regions(dev, domain);
+}
+EXPORT_SYMBOL(iommu_dma_init_domain);
+
+/**
+ * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
+ *                    page flags.
+ * @dir: Direction of DMA transfer
+ * @coherent: Is the DMA master cache-coherent?
+ * @attrs: DMA attributes for the mapping
+ *
+ * Return: corresponding IOMMU API page protection flags
+ */
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+		     unsigned long attrs)
+{
+	int prot = coherent ? IOMMU_CACHE : 0;
+
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
+	switch (dir) {
+	case DMA_BIDIRECTIONAL:
+		return prot | IOMMU_READ | IOMMU_WRITE;
+	case DMA_TO_DEVICE:
+		return prot | IOMMU_READ;
+	case DMA_FROM_DEVICE:
+		return prot | IOMMU_WRITE;
+	default:
+		return 0;
+	}
+}
+
+static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
+		size_t size, dma_addr_t dma_limit, struct device *dev)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	unsigned long shift, iova_len, iova = 0;
+
+	if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
+		cookie->msi_iova += size;
+		return cookie->msi_iova - size;
+	}
+
+	shift = iova_shift(iovad);
+	iova_len = size >> shift;
+	/*
+	 * Freeing non-power-of-two-sized allocations back into the IOVA caches
+	 * will come back to bite us badly, so we have to waste a bit of space
+	 * rounding up anything cacheable to make sure that can't happen. The
+	 * order of the unadjusted size will still match upon freeing.
+	 */
+	if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
+		iova_len = roundup_pow_of_two(iova_len);
+
+	if (domain->geometry.force_aperture)
+		dma_limit = min(dma_limit, domain->geometry.aperture_end);
+
+	/* Try to get PCI devices a SAC address */
+	if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev))
+		iova = alloc_iova_fast(iovad, iova_len, DMA_BIT_MASK(32) >> shift);
+
+	if (!iova)
+		iova = alloc_iova_fast(iovad, iova_len, dma_limit >> shift);
+
+	return (dma_addr_t)iova << shift;
+}
+
+static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
+		dma_addr_t iova, size_t size)
+{
+	struct iova_domain *iovad = &cookie->iovad;
+
+	/* The MSI case is only ever cleaning up its most recent allocation */
+	if (cookie->type == IOMMU_DMA_MSI_COOKIE)
+		cookie->msi_iova -= size;
+	else
+		free_iova_fast(iovad, iova_pfn(iovad, iova),
+				size >> iova_shift(iovad));
+}
+
+static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr,
+		size_t size)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	size_t iova_off = iova_offset(iovad, dma_addr);
+
+	dma_addr -= iova_off;
+	size = iova_align(iovad, size + iova_off);
+
+	WARN_ON(iommu_unmap(domain, dma_addr, size) != size);
+	iommu_dma_free_iova(cookie, dma_addr, size);
+}
+
+static void __iommu_dma_free_pages(struct page **pages, int count)
+{
+	while (count--)
+		__free_page(pages[count]);
+	kvfree(pages);
+}
+
+static struct page **__iommu_dma_alloc_pages(unsigned int count,
+		unsigned long order_mask, gfp_t gfp)
+{
+	struct page **pages;
+	unsigned int i = 0, array_size = count * sizeof(*pages);
+
+	order_mask &= (2U << MAX_ORDER) - 1;
+	if (!order_mask)
+		return NULL;
+
+	if (array_size <= PAGE_SIZE)
+		pages = kzalloc(array_size, GFP_KERNEL);
+	else
+		pages = vzalloc(array_size);
+	if (!pages)
+		return NULL;
+
+	/* IOMMU can map any pages, so himem can also be used here */
+	gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
+
+	while (count) {
+		struct page *page = NULL;
+		unsigned int order_size;
+
+		/*
+		 * Higher-order allocations are a convenience rather
+		 * than a necessity, hence using __GFP_NORETRY until
+		 * falling back to minimum-order allocations.
+		 */
+		for (order_mask &= (2U << __fls(count)) - 1;
+		     order_mask; order_mask &= ~order_size) {
+			unsigned int order = __fls(order_mask);
+
+			order_size = 1U << order;
+			page = alloc_pages((order_mask - order_size) ?
+					   gfp | __GFP_NORETRY : gfp, order);
+			if (!page)
+				continue;
+			if (!order)
+				break;
+			if (!PageCompound(page)) {
+				split_page(page, order);
+				break;
+			} else if (!split_huge_page(page)) {
+				break;
+			}
+			__free_pages(page, order);
+		}
+		if (!page) {
+			__iommu_dma_free_pages(pages, i);
+			return NULL;
+		}
+		count -= order_size;
+		while (order_size--)
+			pages[i++] = page++;
+	}
+	return pages;
+}
+
+
+void iommu_dma_free_from_reserved_range(struct device *dev,
+		struct page **pages, size_t size, dma_addr_t *handle)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	unsigned long shift = iova_shift(iovad);
+	unsigned long pfn = (*handle) >> shift;
+	size_t unmap_size = size;
+
+	unmap_size -= iommu_unmap(domain, pfn << shift, size);
+	WARN_ON(unmap_size > 0);
+
+	__iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
+	*handle = IOMMU_MAPPING_ERROR;
+}
+
+/**
+ * iommu_dma_free - Free a buffer allocated by iommu_dma_alloc()
+ * @dev: Device which owns this buffer
+ * @pages: Array of buffer pages as returned by iommu_dma_alloc()
+ * @size: Size of buffer in bytes
+ * @handle: DMA address of buffer
+ *
+ * Frees both the pages associated with the buffer, and the array
+ * describing them
+ */
+void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
+		dma_addr_t *handle)
+{
+	__iommu_dma_unmap(iommu_get_domain_for_dev(dev), *handle, size);
+	__iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
+	*handle = IOMMU_MAPPING_ERROR;
+}
+
+/**
+ * iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
+ * @dev: Device to allocate memory for. Must be a real device
+ *	 attached to an iommu_dma_domain
+ * @size: Size of buffer in bytes
+ * @gfp: Allocation flags
+ * @attrs: DMA attributes for this allocation
+ * @prot: IOMMU mapping flags
+ * @handle: Out argument for allocated DMA handle
+ * @flush_page: Arch callback which must ensure PAGE_SIZE bytes from the
+ *		given VA/PA are visible to the given non-coherent device.
+ *
+ * If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
+ * but an IOMMU which supports smaller pages might not map the whole thing.
+ *
+ * Return: Array of struct page pointers describing the buffer,
+ *	   or NULL on failure.
+ */
+struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
+		unsigned long attrs, int prot, dma_addr_t *handle,
+		void (*flush_page)(struct device *, const void *, phys_addr_t))
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct page **pages;
+	struct sg_table sgt;
+	dma_addr_t iova;
+	unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
+
+	*handle = IOMMU_MAPPING_ERROR;
+
+	min_size = alloc_sizes & -alloc_sizes;
+	if (min_size < PAGE_SIZE) {
+		min_size = PAGE_SIZE;
+		alloc_sizes |= PAGE_SIZE;
+	} else {
+		size = ALIGN(size, min_size);
+	}
+	if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES)
+		alloc_sizes = min_size;
+
+	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp);
+	if (!pages)
+		return NULL;
+
+	size = iova_align(iovad, size);
+	iova = iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev);
+	if (!iova)
+		goto out_free_pages;
+
+	if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
+		goto out_free_iova;
+
+	if (!(prot & IOMMU_CACHE)) {
+		struct sg_mapping_iter miter;
+		/*
+		 * The CPU-centric flushing implied by SG_MITER_TO_SG isn't
+		 * sufficient here, so skip it by using the "wrong" direction.
+		 */
+		sg_miter_start(&miter, sgt.sgl, sgt.orig_nents, SG_MITER_FROM_SG);
+		while (sg_miter_next(&miter))
+			flush_page(dev, miter.addr, page_to_phys(miter.page));
+		sg_miter_stop(&miter);
+	}
+
+	if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
+			< size)
+		goto out_free_sg;
+
+	*handle = iova;
+	sg_free_table(&sgt);
+	return pages;
+
+out_free_sg:
+	sg_free_table(&sgt);
+out_free_iova:
+	iommu_dma_free_iova(cookie, iova, size);
+out_free_pages:
+	__iommu_dma_free_pages(pages, count);
+	return NULL;
+}
+
+/**
+ * iommu_dma_mmap - Map a buffer into provided user VMA
+ * @pages: Array representing buffer from iommu_dma_alloc()
+ * @size: Size of buffer in bytes
+ * @vma: VMA describing requested userspace mapping
+ *
+ * Maps the pages of the buffer in @pages into @vma. The caller is responsible
+ * for verifying the correct size and protection of @vma beforehand.
+ */
+
+int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma)
+{
+	unsigned long uaddr = vma->vm_start;
+	unsigned int i, count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	int ret = -ENXIO;
+
+	for (i = vma->vm_pgoff; i < count && uaddr < vma->vm_end; i++) {
+		ret = vm_insert_page(vma, uaddr, pages[i]);
+		if (ret)
+			break;
+		uaddr += PAGE_SIZE;
+	}
+	return ret;
+}
+
+static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
+		size_t size, int prot)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	size_t iova_off = 0;
+	dma_addr_t iova;
+
+	if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
+		iova_off = iova_offset(&cookie->iovad, phys);
+		size = iova_align(&cookie->iovad, size + iova_off);
+	}
+
+	iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
+	if (!iova)
+		return IOMMU_MAPPING_ERROR;
+
+	if (iommu_map(domain, iova, phys - iova_off, size, prot)) {
+		iommu_dma_free_iova(cookie, iova, size);
+		return IOMMU_MAPPING_ERROR;
+	}
+	return iova + iova_off;
+}
+
+dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
+		unsigned long offset, size_t size, int prot)
+{
+	return __iommu_dma_map(dev, page_to_phys(page) + offset, size, prot);
+}
+
+void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	__iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle, size);
+}
+
+/*
+ * Prepare a successfully-mapped scatterlist to give back to the caller.
+ *
+ * At this point the segments are already laid out by iommu_dma_map_sg() to
+ * avoid individually crossing any boundaries, so we merely need to check a
+ * segment's start address to avoid concatenating across one.
+ */
+static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents,
+		dma_addr_t dma_addr)
+{
+	struct scatterlist *s, *cur = sg;
+	unsigned long seg_mask = dma_get_seg_boundary(dev);
+	unsigned int cur_len = 0, max_len = dma_get_max_seg_size(dev);
+	int i, count = 0;
+
+	for_each_sg(sg, s, nents, i) {
+		/* Restore this segment's original unaligned fields first */
+		unsigned int s_iova_off = sg_dma_address(s);
+		unsigned int s_length = sg_dma_len(s);
+		unsigned int s_iova_len = s->length;
+
+		s->offset += s_iova_off;
+		s->length = s_length;
+		sg_dma_address(s) = IOMMU_MAPPING_ERROR;
+		sg_dma_len(s) = 0;
+
+		/*
+		 * Now fill in the real DMA data. If...
+		 * - there is a valid output segment to append to
+		 * - and this segment starts on an IOVA page boundary
+		 * - but doesn't fall at a segment boundary
+		 * - and wouldn't make the resulting output segment too long
+		 */
+		if (cur_len && !s_iova_off && (dma_addr & seg_mask) &&
+		    (max_len - cur_len >= s_length)) {
+			/* ...then concatenate it with the previous one */
+			cur_len += s_length;
+		} else {
+			/* Otherwise start the next output segment */
+			if (i > 0)
+				cur = sg_next(cur);
+			cur_len = s_length;
+			count++;
+
+			sg_dma_address(cur) = dma_addr + s_iova_off;
+		}
+
+		sg_dma_len(cur) = cur_len;
+		dma_addr += s_iova_len;
+
+		if (s_length + s_iova_off < s_iova_len)
+			cur_len = 0;
+	}
+	return count;
+}
+
+/*
+ * If mapping failed, then just restore the original list,
+ * but making sure the DMA fields are invalidated.
+ */
+static void __invalidate_sg(struct scatterlist *sg, int nents)
+{
+	struct scatterlist *s;
+	int i;
+
+	for_each_sg(sg, s, nents, i) {
+		if (sg_dma_address(s) != IOMMU_MAPPING_ERROR)
+			s->offset += sg_dma_address(s);
+		if (sg_dma_len(s))
+			s->length = sg_dma_len(s);
+		sg_dma_address(s) = IOMMU_MAPPING_ERROR;
+		sg_dma_len(s) = 0;
+	}
+}
+
+/*
+ * The DMA API client is passing in a scatterlist which could describe
+ * any old buffer layout, but the IOMMU API requires everything to be
+ * aligned to IOMMU pages. Hence the need for this complicated bit of
+ * impedance-matching, to be able to hand off a suitably-aligned list,
+ * but still preserve the original offsets and sizes for the caller.
+ */
+int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
+		int nents, int prot)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct scatterlist *s, *prev = NULL;
+	dma_addr_t iova;
+	size_t iova_len = 0;
+	unsigned long mask = dma_get_seg_boundary(dev);
+	int i;
+
+	/*
+	 * Work out how much IOVA space we need, and align the segments to
+	 * IOVA granules for the IOMMU driver to handle. With some clever
+	 * trickery we can modify the list in-place, but reversibly, by
+	 * stashing the unaligned parts in the as-yet-unused DMA fields.
+	 */
+	for_each_sg(sg, s, nents, i) {
+		size_t s_iova_off = iova_offset(iovad, s->offset);
+		size_t s_length = s->length;
+		size_t pad_len = (mask - iova_len + 1) & mask;
+
+		sg_dma_address(s) = s_iova_off;
+		sg_dma_len(s) = s_length;
+		s->offset -= s_iova_off;
+		s_length = iova_align(iovad, s_length + s_iova_off);
+		s->length = s_length;
+
+		/*
+		 * Due to the alignment of our single IOVA allocation, we can
+		 * depend on these assumptions about the segment boundary mask:
+		 * - If mask size >= IOVA size, then the IOVA range cannot
+		 *   possibly fall across a boundary, so we don't care.
+		 * - If mask size < IOVA size, then the IOVA range must start
+		 *   exactly on a boundary, therefore we can lay things out
+		 *   based purely on segment lengths without needing to know
+		 *   the actual addresses beforehand.
+		 * - The mask must be a power of 2, so pad_len == 0 if
+		 *   iova_len == 0, thus we cannot dereference prev the first
+		 *   time through here (i.e. before it has a meaningful value).
+		 */
+		if (pad_len && pad_len < s_length - 1) {
+			prev->length += pad_len;
+			iova_len += pad_len;
+		}
+
+		iova_len += s_length;
+		prev = s;
+	}
+
+	iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
+	if (!iova)
+		goto out_restore_sg;
+
+	/*
+	 * We'll leave any physical concatenation to the IOMMU driver's
+	 * implementation - it knows better than we do.
+	 */
+	if (iommu_map_sg(domain, iova, sg, nents, prot) < iova_len)
+		goto out_free_iova;
+
+	return __finalise_sg(dev, sg, nents, iova);
+
+out_free_iova:
+	iommu_dma_free_iova(cookie, iova, iova_len);
+out_restore_sg:
+	__invalidate_sg(sg, nents);
+	return 0;
+}
+
+void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	dma_addr_t start, end;
+	struct scatterlist *tmp;
+	int i;
+	/*
+	 * The scatterlist segments are mapped into a single
+	 * contiguous IOVA allocation, so this is incredibly easy.
+	 */
+	start = sg_dma_address(sg);
+	for_each_sg(sg_next(sg), tmp, nents - 1, i) {
+		if (sg_dma_len(tmp) == 0)
+			break;
+		sg = tmp;
+	}
+	end = sg_dma_address(sg) + sg_dma_len(sg);
+	__iommu_dma_unmap(iommu_get_domain_for_dev(dev), start, end - start);
+}
+
+struct page **
+iommu_dma_alloc_fix_iova(struct device *dev, size_t size, gfp_t gfp,
+		unsigned long attrs, int prot, dma_addr_t handle,
+		void (*flush_page)(struct device *, const void *, phys_addr_t))
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct page **pages;
+	struct sg_table sgt;
+	dma_addr_t iova = handle;
+	unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
+
+	min_size = alloc_sizes & -alloc_sizes;
+	if (min_size < PAGE_SIZE) {
+		min_size = PAGE_SIZE;
+		alloc_sizes |= PAGE_SIZE;
+	} else {
+		size = ALIGN(size, min_size);
+	}
+	if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES)
+		alloc_sizes = min_size;
+
+	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp);
+	if (!pages)
+		return NULL;
+
+	size = iova_align(iovad, size);
+	if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
+		goto out_free_iova;
+
+	if (!(prot & IOMMU_CACHE)) {
+		struct sg_mapping_iter miter;
+		/*
+		 * The CPU-centric flushing implied by SG_MITER_TO_SG isn't
+		 * sufficient here, so skip it by using the "wrong" direction.
+		 */
+		sg_miter_start(&miter, sgt.sgl, sgt.orig_nents,
+			       SG_MITER_FROM_SG);
+		while (sg_miter_next(&miter))
+			flush_page(dev, miter.addr, page_to_phys(miter.page));
+		sg_miter_stop(&miter);
+	}
+
+	if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
+			< size)
+		goto out_free_sg;
+
+	sg_free_table(&sgt);
+	return pages;
+
+out_free_sg:
+	sg_free_table(&sgt);
+out_free_iova:
+	iommu_dma_free_iova(cookie, iova, size);
+	__iommu_dma_free_pages(pages, count);
+	return NULL;
+}
+
+/*
+ * User have to provide the dma address in the reserved iova area for mapping
+ */
+int dma_map_sg_within_reserved_iova(struct device *dev, struct scatterlist *sg,
+				    int nents, int prot, dma_addr_t dma_addr)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct scatterlist *s, *prev = NULL;
+	size_t iova_len = 0;
+	size_t map_len = 0;
+	int i;
+
+	for_each_sg(sg, s, nents, i) {
+		size_t s_iova_off = iova_offset(iovad, s->offset);
+		size_t s_length = s->length;
+
+		sg_dma_address(s) = s_iova_off;
+		sg_dma_len(s) = s_length;
+		s->offset -= s_iova_off;
+		s_length = iova_align(iovad, s_length + s_iova_off);
+		s->length = s_length;
+
+		iova_len += s_length;
+		prev = s;
+	}
+
+	map_len = iommu_map_sg(domain, dma_addr, sg, nents, prot);
+
+	return __finalise_sg(dev, sg, nents, dma_addr);
+}
+EXPORT_SYMBOL(dma_map_sg_within_reserved_iova);
+
+void dma_unmap_sg_within_reserved_iova(struct device *dev,
+				       struct scatterlist *sg, int nents,
+				       int prot, size_t size)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	unsigned long shift = iova_shift(iovad);
+	unsigned long pfn = sg_dma_address(sg) >> shift;
+
+	/*
+	 * The scatterlist segments are mapped into a single
+	 * contiguous IOVA allocation, so this is incredibly easy.
+	 */
+	size -= iommu_unmap(domain, pfn << shift, size);
+	WARN_ON(size > 0);
+}
+EXPORT_SYMBOL(dma_unmap_sg_within_reserved_iova);
+
+dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	return __iommu_dma_map(dev, phys, size,
+			dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);
+}
+
+void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	__iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle, size);
+}
+
+int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_addr == IOMMU_MAPPING_ERROR;
+}
+
+static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
+		phys_addr_t msi_addr, struct iommu_domain *domain)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iommu_dma_msi_page *msi_page;
+	dma_addr_t iova;
+	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+	size_t size = cookie_msi_granule(cookie);
+
+	msi_addr &= ~(phys_addr_t)(size - 1);
+	list_for_each_entry(msi_page, &cookie->msi_page_list, list)
+		if (msi_page->phys == msi_addr)
+			return msi_page;
+
+	msi_page = kzalloc(sizeof(*msi_page), GFP_ATOMIC);
+	if (!msi_page)
+		return NULL;
+
+	iova = __iommu_dma_map(dev, msi_addr, size, prot);
+	if (iommu_dma_mapping_error(dev, iova))
+		goto out_free_page;
+
+	INIT_LIST_HEAD(&msi_page->list);
+	msi_page->phys = msi_addr;
+	msi_page->iova = iova;
+	list_add(&msi_page->list, &cookie->msi_page_list);
+	return msi_page;
+
+out_free_page:
+	kfree(msi_page);
+	return NULL;
+}
+
+void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
+{
+	struct device *dev = msi_desc_to_dev(irq_get_msi_desc(irq));
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+	struct iommu_dma_cookie *cookie;
+	struct iommu_dma_msi_page *msi_page;
+	phys_addr_t msi_addr = (u64)msg->address_hi << 32 | msg->address_lo;
+	unsigned long flags;
+
+	if (!domain || !domain->iova_cookie)
+		return;
+
+	cookie = domain->iova_cookie;
+
+	/*
+	 * We disable IRQs to rule out a possible inversion against
+	 * irq_desc_lock if, say, someone tries to retarget the affinity
+	 * of an MSI from within an IPI handler.
+	 */
+	spin_lock_irqsave(&cookie->msi_lock, flags);
+	msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain);
+	spin_unlock_irqrestore(&cookie->msi_lock, flags);
+
+	if (WARN_ON(!msi_page)) {
+		/*
+		 * We're called from a void callback, so the best we can do is
+		 * 'fail' by filling the message with obviously bogus values.
+		 * Since we got this far due to an IOMMU being present, it's
+		 * not like the existing address would have worked anyway...
+		 */
+		msg->address_hi = ~0U;
+		msg->address_lo = ~0U;
+		msg->data = ~0U;
+	} else {
+		msg->address_hi = upper_32_bits(msi_page->iova);
+		msg->address_lo &= cookie_msi_granule(cookie) - 1;
+		msg->address_lo += lower_32_bits(msi_page->iova);
+	}
+}