1 files changed, 220 insertions, 505 deletions

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 82fc54f8eb77..ccf25027bec1 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -1,18 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright 2010
  *  by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  *
  * This code provides a IOMMU for Xen PV guests with PCI passthrough.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License v2.0 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.
- *
  * PV guests under Xen are running in an non-contiguous memory architecture.
  *
  * When PCI pass-through is utilized, this necessitates an IOMMU for
@@ -30,13 +22,13 @@
  * and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are
  * allocated in descending order (high to low), meaning the guest might
  * never get any MFN's under the 4GB mark.
- *
  */
 
 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
 
-#include <linux/bootmem.h>
-#include <linux/dma-mapping.h>
+#include <linux/memblock.h>
+#include <linux/dma-direct.h>
+#include <linux/dma-map-ops.h>
 #include <linux/export.h>
 #include <xen/swiotlb-xen.h>
 #include <xen/page.h>
@@ -44,492 +36,315 @@
 #include <xen/hvc-console.h>
 
 #include <asm/dma-mapping.h>
-#include <asm/xen/page-coherent.h>
 
 #include <trace/events/swiotlb.h>
-/*
- * Used to do a quick range check in swiotlb_tbl_unmap_single and
- * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
- * API.
- */
+#define MAX_DMA_BITS 32
 
-#ifndef CONFIG_X86
-static unsigned long dma_alloc_coherent_mask(struct device *dev,
-					    gfp_t gfp)
-{
-	unsigned long dma_mask = 0;
-
-	dma_mask = dev->coherent_dma_mask;
-	if (!dma_mask)
-		dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
-
-	return dma_mask;
-}
-#endif
-
-#define XEN_SWIOTLB_ERROR_CODE	(~(dma_addr_t)0x0)
-
-static char *xen_io_tlb_start, *xen_io_tlb_end;
-static unsigned long xen_io_tlb_nslabs;
 /*
  * Quick lookup value of the bus address of the IOTLB.
  */
 
-static u64 start_dma_addr;
-
-/*
- * Both of these functions should avoid XEN_PFN_PHYS because phys_addr_t
- * can be 32bit when dma_addr_t is 64bit leading to a loss in
- * information if the shift is done before casting to 64bit.
- */
-static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
+static inline phys_addr_t xen_phys_to_bus(struct device *dev, phys_addr_t paddr)
 {
 	unsigned long bfn = pfn_to_bfn(XEN_PFN_DOWN(paddr));
-	dma_addr_t dma = (dma_addr_t)bfn << XEN_PAGE_SHIFT;
+	phys_addr_t baddr = (phys_addr_t)bfn << XEN_PAGE_SHIFT;
 
-	dma |= paddr & ~XEN_PAGE_MASK;
+	baddr |= paddr & ~XEN_PAGE_MASK;
+	return baddr;
+}
 
-	return dma;
+static inline dma_addr_t xen_phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	return phys_to_dma(dev, xen_phys_to_bus(dev, paddr));
 }
 
-static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
+static inline phys_addr_t xen_bus_to_phys(struct device *dev,
+					  phys_addr_t baddr)
 {
 	unsigned long xen_pfn = bfn_to_pfn(XEN_PFN_DOWN(baddr));
-	dma_addr_t dma = (dma_addr_t)xen_pfn << XEN_PAGE_SHIFT;
-	phys_addr_t paddr = dma;
-
-	paddr |= baddr & ~XEN_PAGE_MASK;
+	phys_addr_t paddr = (xen_pfn << XEN_PAGE_SHIFT) |
+			    (baddr & ~XEN_PAGE_MASK);
 
 	return paddr;
 }
 
-static inline dma_addr_t xen_virt_to_bus(void *address)
+static inline phys_addr_t xen_dma_to_phys(struct device *dev,
+					  dma_addr_t dma_addr)
 {
-	return xen_phys_to_bus(virt_to_phys(address));
+	return xen_bus_to_phys(dev, dma_to_phys(dev, dma_addr));
 }
 
-static int check_pages_physically_contiguous(unsigned long xen_pfn,
-					     unsigned int offset,
-					     size_t length)
+static inline bool range_requires_alignment(phys_addr_t p, size_t size)
 {
-	unsigned long next_bfn;
-	int i;
-	int nr_pages;
+	phys_addr_t algn = 1ULL << (get_order(size) + PAGE_SHIFT);
+	phys_addr_t bus_addr = pfn_to_bfn(XEN_PFN_DOWN(p)) << XEN_PAGE_SHIFT;
 
-	next_bfn = pfn_to_bfn(xen_pfn);
-	nr_pages = (offset + length + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT;
-
-	for (i = 1; i < nr_pages; i++) {
-		if (pfn_to_bfn(++xen_pfn) != ++next_bfn)
-			return 0;
-	}
-	return 1;
+	return IS_ALIGNED(p, algn) && !IS_ALIGNED(bus_addr, algn);
 }
 
 static inline int range_straddles_page_boundary(phys_addr_t p, size_t size)
 {
-	unsigned long xen_pfn = XEN_PFN_DOWN(p);
-	unsigned int offset = p & ~XEN_PAGE_MASK;
-
-	if (offset + size <= XEN_PAGE_SIZE)
-		return 0;
-	if (check_pages_physically_contiguous(xen_pfn, offset, size))
-		return 0;
-	return 1;
+	unsigned long next_bfn, xen_pfn = XEN_PFN_DOWN(p);
+	unsigned int i, nr_pages = XEN_PFN_UP(xen_offset_in_page(p) + size);
+
+	next_bfn = pfn_to_bfn(xen_pfn);
+
+	for (i = 1; i < nr_pages; i++)
+		if (pfn_to_bfn(++xen_pfn) != ++next_bfn)
+			return 1;
+
+	return 0;
 }
 
-static int is_xen_swiotlb_buffer(dma_addr_t dma_addr)
+static struct io_tlb_pool *xen_swiotlb_find_pool(struct device *dev,
+						 dma_addr_t dma_addr)
 {
-	unsigned long bfn = XEN_PFN_DOWN(dma_addr);
+	unsigned long bfn = XEN_PFN_DOWN(dma_to_phys(dev, dma_addr));
 	unsigned long xen_pfn = bfn_to_local_pfn(bfn);
-	phys_addr_t paddr = XEN_PFN_PHYS(xen_pfn);
+	phys_addr_t paddr = (phys_addr_t)xen_pfn << XEN_PAGE_SHIFT;
 
 	/* If the address is outside our domain, it CAN
 	 * have the same virtual address as another address
 	 * in our domain. Therefore _only_ check address within our domain.
 	 */
-	if (pfn_valid(PFN_DOWN(paddr))) {
-		return paddr >= virt_to_phys(xen_io_tlb_start) &&
-		       paddr < virt_to_phys(xen_io_tlb_end);
-	}
-	return 0;
+	if (pfn_valid(PFN_DOWN(paddr)))
+		return swiotlb_find_pool(dev, paddr);
+	return NULL;
 }
 
-static int max_dma_bits = 32;
-
-static int
-xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
+#ifdef CONFIG_X86
+int __init xen_swiotlb_fixup(void *buf, unsigned long nslabs)
 {
-	int i, rc;
-	int dma_bits;
+	int rc;
+	unsigned int order = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT);
+	unsigned int i, dma_bits = order + PAGE_SHIFT;
 	dma_addr_t dma_handle;
 	phys_addr_t p = virt_to_phys(buf);
 
-	dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
+	BUILD_BUG_ON(IO_TLB_SEGSIZE & (IO_TLB_SEGSIZE - 1));
+	BUG_ON(nslabs % IO_TLB_SEGSIZE);
 
 	i = 0;
 	do {
-		int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE);
-
 		do {
 			rc = xen_create_contiguous_region(
-				p + (i << IO_TLB_SHIFT),
-				get_order(slabs << IO_TLB_SHIFT),
+				p + (i << IO_TLB_SHIFT), order,
 				dma_bits, &dma_handle);
-		} while (rc && dma_bits++ < max_dma_bits);
+		} while (rc && dma_bits++ < MAX_DMA_BITS);
 		if (rc)
 			return rc;
 
-		i += slabs;
+		i += IO_TLB_SEGSIZE;
 	} while (i < nslabs);
 	return 0;
 }
-static unsigned long xen_set_nslabs(unsigned long nr_tbl)
-{
-	if (!nr_tbl) {
-		xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
-		xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
-	} else
-		xen_io_tlb_nslabs = nr_tbl;
-
-	return xen_io_tlb_nslabs << IO_TLB_SHIFT;
-}
-
-enum xen_swiotlb_err {
-	XEN_SWIOTLB_UNKNOWN = 0,
-	XEN_SWIOTLB_ENOMEM,
-	XEN_SWIOTLB_EFIXUP
-};
-
-static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
-{
-	switch (err) {
-	case XEN_SWIOTLB_ENOMEM:
-		return "Cannot allocate Xen-SWIOTLB buffer\n";
-	case XEN_SWIOTLB_EFIXUP:
-		return "Failed to get contiguous memory for DMA from Xen!\n"\
-		    "You either: don't have the permissions, do not have"\
-		    " enough free memory under 4GB, or the hypervisor memory"\
-		    " is too fragmented!";
-	default:
-		break;
-	}
-	return "";
-}
-int __ref xen_swiotlb_init(int verbose, bool early)
-{
-	unsigned long bytes, order;
-	int rc = -ENOMEM;
-	enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
-	unsigned int repeat = 3;
-
-	xen_io_tlb_nslabs = swiotlb_nr_tbl();
-retry:
-	bytes = xen_set_nslabs(xen_io_tlb_nslabs);
-	order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT);
-	/*
-	 * Get IO TLB memory from any location.
-	 */
-	if (early)
-		xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
-	else {
-#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
-#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
-		while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
-			xen_io_tlb_start = (void *)xen_get_swiotlb_free_pages(order);
-			if (xen_io_tlb_start)
-				break;
-			order--;
-		}
-		if (order != get_order(bytes)) {
-			pr_warn("Warning: only able to allocate %ld MB for software IO TLB\n",
-				(PAGE_SIZE << order) >> 20);
-			xen_io_tlb_nslabs = SLABS_PER_PAGE << order;
-			bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
-		}
-	}
-	if (!xen_io_tlb_start) {
-		m_ret = XEN_SWIOTLB_ENOMEM;
-		goto error;
-	}
-	xen_io_tlb_end = xen_io_tlb_start + bytes;
-	/*
-	 * And replace that memory with pages under 4GB.
-	 */
-	rc = xen_swiotlb_fixup(xen_io_tlb_start,
-			       bytes,
-			       xen_io_tlb_nslabs);
-	if (rc) {
-		if (early)
-			free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
-		else {
-			free_pages((unsigned long)xen_io_tlb_start, order);
-			xen_io_tlb_start = NULL;
-		}
-		m_ret = XEN_SWIOTLB_EFIXUP;
-		goto error;
-	}
-	start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
-	if (early) {
-		if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
-			 verbose))
-			panic("Cannot allocate SWIOTLB buffer");
-		rc = 0;
-	} else
-		rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);
-
-	if (!rc)
-		swiotlb_set_max_segment(PAGE_SIZE);
-
-	return rc;
-error:
-	if (repeat--) {
-		xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
-					(xen_io_tlb_nslabs >> 1));
-		pr_info("Lowering to %luMB\n",
-			(xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
-		goto retry;
-	}
-	pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc);
-	if (early)
-		panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
-	else
-		free_pages((unsigned long)xen_io_tlb_start, order);
-	return rc;
-}
 
 static void *
-xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
-			   dma_addr_t *dma_handle, gfp_t flags,
-			   unsigned long attrs)
+xen_swiotlb_alloc_coherent(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
 {
-	void *ret;
+	u64 dma_mask = dev->coherent_dma_mask;
 	int order = get_order(size);
-	u64 dma_mask = DMA_BIT_MASK(32);
 	phys_addr_t phys;
-	dma_addr_t dev_addr;
+	void *ret;
 
-	/*
-	* Ignore region specifiers - the kernel's ideas of
-	* pseudo-phys memory layout has nothing to do with the
-	* machine physical layout.  We can't allocate highmem
-	* because we can't return a pointer to it.
-	*/
-	flags &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
-	/* On ARM this function returns an ioremap'ped virtual address for
-	 * which virt_to_phys doesn't return the corresponding physical
-	 * address. In fact on ARM virt_to_phys only works for kernel direct
-	 * mapped RAM memory. Also see comment below.
-	 */
-	ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs);
+	/* Align the allocation to the Xen page size */
+	size = ALIGN(size, XEN_PAGE_SIZE);
 
+	ret = (void *)__get_free_pages(flags, get_order(size));
 	if (!ret)
 		return ret;
-
-	if (hwdev && hwdev->coherent_dma_mask)
-		dma_mask = dma_alloc_coherent_mask(hwdev, flags);
-
-	/* At this point dma_handle is the physical address, next we are
-	 * going to set it to the machine address.
-	 * Do not use virt_to_phys(ret) because on ARM it doesn't correspond
-	 * to *dma_handle. */
-	phys = *dma_handle;
-	dev_addr = xen_phys_to_bus(phys);
-	if (((dev_addr + size - 1 <= dma_mask)) &&
-	    !range_straddles_page_boundary(phys, size))
-		*dma_handle = dev_addr;
-	else {
-		if (xen_create_contiguous_region(phys, order,
-						 fls64(dma_mask), dma_handle) != 0) {
-			xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs);
-			return NULL;
-		}
+	phys = virt_to_phys(ret);
+
+	*dma_handle = xen_phys_to_dma(dev, phys);
+	if (*dma_handle + size - 1 > dma_mask ||
+	    range_straddles_page_boundary(phys, size) ||
+	    range_requires_alignment(phys, size)) {
+		if (xen_create_contiguous_region(phys, order, fls64(dma_mask),
+				dma_handle) != 0)
+			goto out_free_pages;
+		SetPageXenRemapped(virt_to_page(ret));
 	}
+
 	memset(ret, 0, size);
 	return ret;
+
+out_free_pages:
+	free_pages((unsigned long)ret, get_order(size));
+	return NULL;
 }
 
 static void
-xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
-			  dma_addr_t dev_addr, unsigned long attrs)
+xen_swiotlb_free_coherent(struct device *dev, size_t size, void *vaddr,
+		dma_addr_t dma_handle, unsigned long attrs)
 {
+	phys_addr_t phys = virt_to_phys(vaddr);
 	int order = get_order(size);
-	phys_addr_t phys;
-	u64 dma_mask = DMA_BIT_MASK(32);
 
-	if (hwdev && hwdev->coherent_dma_mask)
-		dma_mask = hwdev->coherent_dma_mask;
+	/* Convert the size to actually allocated. */
+	size = ALIGN(size, XEN_PAGE_SIZE);
 
-	/* do not use virt_to_phys because on ARM it doesn't return you the
-	 * physical address */
-	phys = xen_bus_to_phys(dev_addr);
+	if (WARN_ON_ONCE(dma_handle + size - 1 > dev->coherent_dma_mask) ||
+	    WARN_ON_ONCE(range_straddles_page_boundary(phys, size) ||
+			 range_requires_alignment(phys, size)))
+	    	return;
 
-	if (((dev_addr + size - 1 > dma_mask)) ||
-	    range_straddles_page_boundary(phys, size))
+	if (TestClearPageXenRemapped(virt_to_page(vaddr)))
 		xen_destroy_contiguous_region(phys, order);
-
-	xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
+	free_pages((unsigned long)vaddr, get_order(size));
 }
+#endif /* CONFIG_X86 */
 
 /*
  * Map a single buffer of the indicated size for DMA in streaming mode.  The
  * physical address to use is returned.
  *
  * Once the device is given the dma address, the device owns this memory until
- * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed.
+ * either xen_swiotlb_unmap_phys or xen_swiotlb_dma_sync_single is performed.
  */
-static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
-				unsigned long offset, size_t size,
-				enum dma_data_direction dir,
+static dma_addr_t xen_swiotlb_map_phys(struct device *dev, phys_addr_t phys,
+				size_t size, enum dma_data_direction dir,
 				unsigned long attrs)
 {
-	phys_addr_t map, phys = page_to_phys(page) + offset;
-	dma_addr_t dev_addr = xen_phys_to_bus(phys);
+	dma_addr_t dev_addr;
+	phys_addr_t map;
 
 	BUG_ON(dir == DMA_NONE);
+
+	if (attrs & DMA_ATTR_MMIO) {
+		if (unlikely(!dma_capable(dev, phys, size, false))) {
+			dev_err_once(
+				dev,
+				"DMA addr %pa+%zu overflow (mask %llx, bus limit %llx).\n",
+				&phys, size, *dev->dma_mask,
+				dev->bus_dma_limit);
+			WARN_ON_ONCE(1);
+			return DMA_MAPPING_ERROR;
+		}
+		return phys;
+	}
+
+	dev_addr = xen_phys_to_dma(dev, phys);
+
 	/*
 	 * If the address happens to be in the device's DMA window,
 	 * we can safely return the device addr and not worry about bounce
 	 * buffering it.
 	 */
-	if (dma_capable(dev, dev_addr, size) &&
+	if (dma_capable(dev, dev_addr, size, true) &&
+	    !dma_kmalloc_needs_bounce(dev, size, dir) &&
 	    !range_straddles_page_boundary(phys, size) &&
 		!xen_arch_need_swiotlb(dev, phys, dev_addr) &&
-		(swiotlb_force != SWIOTLB_FORCE)) {
-		/* we are not interested in the dma_addr returned by
-		 * xen_dma_map_page, only in the potential cache flushes executed
-		 * by the function. */
-		xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
-		return dev_addr;
-	}
+		!is_swiotlb_force_bounce(dev))
+		goto done;
 
 	/*
 	 * Oh well, have to allocate and map a bounce buffer.
 	 */
-	trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
+	trace_swiotlb_bounced(dev, dev_addr, size);
 
-	map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
-				     attrs);
-	if (map == SWIOTLB_MAP_ERROR)
-		return XEN_SWIOTLB_ERROR_CODE;
+	map = swiotlb_tbl_map_single(dev, phys, size, 0, dir, attrs);
+	if (map == (phys_addr_t)DMA_MAPPING_ERROR)
+		return DMA_MAPPING_ERROR;
 
-	dev_addr = xen_phys_to_bus(map);
-	xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
-					dev_addr, map & ~PAGE_MASK, size, dir, attrs);
+	phys = map;
+	dev_addr = xen_phys_to_dma(dev, map);
 
 	/*
 	 * Ensure that the address returned is DMA'ble
 	 */
-	if (dma_capable(dev, dev_addr, size))
-		return dev_addr;
-
-	attrs |= DMA_ATTR_SKIP_CPU_SYNC;
-	swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);
+	if (unlikely(!dma_capable(dev, dev_addr, size, true))) {
+		__swiotlb_tbl_unmap_single(dev, map, size, dir,
+				attrs | DMA_ATTR_SKIP_CPU_SYNC,
+				swiotlb_find_pool(dev, map));
+		return DMA_MAPPING_ERROR;
+	}
 
-	return XEN_SWIOTLB_ERROR_CODE;
+done:
+	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
+		if (pfn_valid(PFN_DOWN(dma_to_phys(dev, dev_addr))))
+			arch_sync_dma_for_device(phys, size, dir);
+		else
+			xen_dma_sync_for_device(dev, dev_addr, size, dir);
+	}
+	return dev_addr;
 }
 
 /*
  * Unmap a single streaming mode DMA translation.  The dma_addr and size must
- * match what was provided for in a previous xen_swiotlb_map_page call.  All
+ * match what was provided for in a previous xen_swiotlb_map_phys call.  All
  * other usages are undefined.
  *
  * After this call, reads by the cpu to the buffer are guaranteed to see
  * whatever the device wrote there.
  */
-static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
-			     size_t size, enum dma_data_direction dir,
-			     unsigned long attrs)
+static void xen_swiotlb_unmap_phys(struct device *hwdev, dma_addr_t dev_addr,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
-	phys_addr_t paddr = xen_bus_to_phys(dev_addr);
+	phys_addr_t paddr = xen_dma_to_phys(hwdev, dev_addr);
+	struct io_tlb_pool *pool;
 
 	BUG_ON(dir == DMA_NONE);
 
-	xen_dma_unmap_page(hwdev, dev_addr, size, dir, attrs);
-
-	/* NOTE: We use dev_addr here, not paddr! */
-	if (is_xen_swiotlb_buffer(dev_addr)) {
-		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);
-		return;
+	if (!dev_is_dma_coherent(hwdev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
+		if (pfn_valid(PFN_DOWN(dma_to_phys(hwdev, dev_addr))))
+			arch_sync_dma_for_cpu(paddr, size, dir);
+		else
+			xen_dma_sync_for_cpu(hwdev, dev_addr, size, dir);
 	}
 
-	if (dir != DMA_FROM_DEVICE)
-		return;
-
-	/*
-	 * phys_to_virt doesn't work with hihgmem page but we could
-	 * call dma_mark_clean() with hihgmem page here. However, we
-	 * are fine since dma_mark_clean() is null on POWERPC. We can
-	 * make dma_mark_clean() take a physical address if necessary.
-	 */
-	dma_mark_clean(phys_to_virt(paddr), size);
-}
-
-static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
-			    size_t size, enum dma_data_direction dir,
-			    unsigned long attrs)
-{
-	xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
+	/* NOTE: We use dev_addr here, not paddr! */
+	pool = xen_swiotlb_find_pool(hwdev, dev_addr);
+	if (pool)
+		__swiotlb_tbl_unmap_single(hwdev, paddr, size, dir,
+					   attrs, pool);
 }
 
-/*
- * Make physical memory consistent for a single streaming mode DMA translation
- * after a transfer.
- *
- * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer
- * using the cpu, yet do not wish to teardown the dma mapping, you must
- * call this function before doing so.  At the next point you give the dma
- * address back to the card, you must first perform a
- * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer
- */
 static void
-xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
-			size_t size, enum dma_data_direction dir,
-			enum dma_sync_target target)
+xen_swiotlb_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr,
+		size_t size, enum dma_data_direction dir)
 {
-	phys_addr_t paddr = xen_bus_to_phys(dev_addr);
-
-	BUG_ON(dir == DMA_NONE);
-
-	if (target == SYNC_FOR_CPU)
-		xen_dma_sync_single_for_cpu(hwdev, dev_addr, size, dir);
-
-	/* NOTE: We use dev_addr here, not paddr! */
-	if (is_xen_swiotlb_buffer(dev_addr))
-		swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
-
-	if (target == SYNC_FOR_DEVICE)
-		xen_dma_sync_single_for_device(hwdev, dev_addr, size, dir);
-
-	if (dir != DMA_FROM_DEVICE)
-		return;
-
-	dma_mark_clean(phys_to_virt(paddr), size);
-}
+	phys_addr_t paddr = xen_dma_to_phys(dev, dma_addr);
+	struct io_tlb_pool *pool;
+
+	if (!dev_is_dma_coherent(dev)) {
+		if (pfn_valid(PFN_DOWN(dma_to_phys(dev, dma_addr))))
+			arch_sync_dma_for_cpu(paddr, size, dir);
+		else
+			xen_dma_sync_for_cpu(dev, dma_addr, size, dir);
+	}
 
-void
-xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
-				size_t size, enum dma_data_direction dir)
-{
-	xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
+	pool = xen_swiotlb_find_pool(dev, dma_addr);
+	if (pool)
+		__swiotlb_sync_single_for_cpu(dev, paddr, size, dir, pool);
 }
 
-void
-xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
-				   size_t size, enum dma_data_direction dir)
+static void
+xen_swiotlb_sync_single_for_device(struct device *dev, dma_addr_t dma_addr,
+		size_t size, enum dma_data_direction dir)
 {
-	xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
+	phys_addr_t paddr = xen_dma_to_phys(dev, dma_addr);
+	struct io_tlb_pool *pool;
+
+	pool = xen_swiotlb_find_pool(dev, dma_addr);
+	if (pool)
+		__swiotlb_sync_single_for_device(dev, paddr, size, dir, pool);
+
+	if (!dev_is_dma_coherent(dev)) {
+		if (pfn_valid(PFN_DOWN(dma_to_phys(dev, dma_addr))))
+			arch_sync_dma_for_device(paddr, size, dir);
+		else
+			xen_dma_sync_for_device(dev, dma_addr, size, dir);
+	}
 }
 
 /*
  * Unmap a set of streaming mode DMA translations.  Again, cpu read rules
- * concerning calls here are the same as for swiotlb_unmap_page() above.
+ * concerning calls here are the same as for swiotlb_unmap_phys() above.
  */
 static void
-xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
-			   int nelems, enum dma_data_direction dir,
-			   unsigned long attrs)
+xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
+		enum dma_data_direction dir, unsigned long attrs)
 {
 	struct scatterlist *sg;
 	int i;
@@ -537,30 +352,14 @@ xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
 	BUG_ON(dir == DMA_NONE);
 
 	for_each_sg(sgl, sg, nelems, i)
-		xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs);
+		xen_swiotlb_unmap_phys(hwdev, sg->dma_address, sg_dma_len(sg),
+				dir, attrs);
 
 }
 
-/*
- * Map a set of buffers described by scatterlist in streaming mode for DMA.
- * This is the scatter-gather version of the above xen_swiotlb_map_page
- * interface.  Here the scatter gather list elements are each tagged with the
- * appropriate dma address and length.  They are obtained via
- * sg_dma_{address,length}(SG).
- *
- * NOTE: An implementation may be able to use a smaller number of
- *       DMA address/length pairs than there are SG table elements.
- *       (for example via virtual mapping capabilities)
- *       The routine returns the number of addr/length pairs actually
- *       used, at most nents.
- *
- * Device ownership issues as mentioned above for xen_swiotlb_map_page are the
- * same here.
- */
 static int
-xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
-			 int nelems, enum dma_data_direction dir,
-			 unsigned long attrs)
+xen_swiotlb_map_sg(struct device *dev, struct scatterlist *sgl, int nelems,
+		enum dma_data_direction dir, unsigned long attrs)
 {
 	struct scatterlist *sg;
 	int i;
@@ -568,85 +367,44 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
 	BUG_ON(dir == DMA_NONE);
 
 	for_each_sg(sgl, sg, nelems, i) {
-		phys_addr_t paddr = sg_phys(sg);
-		dma_addr_t dev_addr = xen_phys_to_bus(paddr);
-
-		if (swiotlb_force == SWIOTLB_FORCE ||
-		    xen_arch_need_swiotlb(hwdev, paddr, dev_addr) ||
-		    !dma_capable(hwdev, dev_addr, sg->length) ||
-		    range_straddles_page_boundary(paddr, sg->length)) {
-			phys_addr_t map = swiotlb_tbl_map_single(hwdev,
-								 start_dma_addr,
-								 sg_phys(sg),
-								 sg->length,
-								 dir, attrs);
-			if (map == SWIOTLB_MAP_ERROR) {
-				dev_warn(hwdev, "swiotlb buffer is full\n");
-				/* Don't panic here, we expect map_sg users
-				   to do proper error handling. */
-				attrs |= DMA_ATTR_SKIP_CPU_SYNC;
-				xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
-							   attrs);
-				sg_dma_len(sgl) = 0;
-				return 0;
-			}
-			dev_addr = xen_phys_to_bus(map);
-			xen_dma_map_page(hwdev, pfn_to_page(map >> PAGE_SHIFT),
-						dev_addr,
-						map & ~PAGE_MASK,
-						sg->length,
-						dir,
-						attrs);
-			sg->dma_address = dev_addr;
-		} else {
-			/* we are not interested in the dma_addr returned by
-			 * xen_dma_map_page, only in the potential cache flushes executed
-			 * by the function. */
-			xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),
-						dev_addr,
-						paddr & ~PAGE_MASK,
-						sg->length,
-						dir,
-						attrs);
-			sg->dma_address = dev_addr;
-		}
+		sg->dma_address = xen_swiotlb_map_phys(dev, sg_phys(sg),
+				sg->length, dir, attrs);
+		if (sg->dma_address == DMA_MAPPING_ERROR)
+			goto out_unmap;
 		sg_dma_len(sg) = sg->length;
 	}
+
 	return nelems;
+out_unmap:
+	xen_swiotlb_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
+	sg_dma_len(sgl) = 0;
+	return -EIO;
 }
 
-/*
- * Make physical memory consistent for a set of streaming mode DMA translations
- * after a transfer.
- *
- * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
- * and usage.
- */
 static void
-xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
-		    int nelems, enum dma_data_direction dir,
-		    enum dma_sync_target target)
+xen_swiotlb_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
+			    int nelems, enum dma_data_direction dir)
 {
 	struct scatterlist *sg;
 	int i;
 
-	for_each_sg(sgl, sg, nelems, i)
-		xen_swiotlb_sync_single(hwdev, sg->dma_address,
-					sg_dma_len(sg), dir, target);
-}
-
-static void
-xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
-			    int nelems, enum dma_data_direction dir)
-{
-	xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
+	for_each_sg(sgl, sg, nelems, i) {
+		xen_swiotlb_sync_single_for_cpu(dev, sg->dma_address,
+				sg->length, dir);
+	}
 }
 
 static void
-xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
+xen_swiotlb_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
 			       int nelems, enum dma_data_direction dir)
 {
-	xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(sgl, sg, nelems, i) {
+		xen_swiotlb_sync_single_for_device(dev, sg->dma_address,
+				sg->length, dir);
+	}
 }
 
 /*
@@ -658,72 +416,29 @@ xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
 static int
 xen_swiotlb_dma_supported(struct device *hwdev, u64 mask)
 {
-	return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask;
-}
-
-/*
- * Create userspace mapping for the DMA-coherent memory.
- * This function should be called with the pages from the current domain only,
- * passing pages mapped from other domains would lead to memory corruption.
- */
-static int
-xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		     void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		     unsigned long attrs)
-{
-#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
-	if (xen_get_dma_ops(dev)->mmap)
-		return xen_get_dma_ops(dev)->mmap(dev, vma, cpu_addr,
-						    dma_addr, size, attrs);
-#endif
-	return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
-}
-
-/*
- * This function should be called with the pages from the current domain only,
- * passing pages mapped from other domains would lead to memory corruption.
- */
-static int
-xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
-			void *cpu_addr, dma_addr_t handle, size_t size,
-			unsigned long attrs)
-{
-#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
-	if (xen_get_dma_ops(dev)->get_sgtable) {
-#if 0
-	/*
-	 * This check verifies that the page belongs to the current domain and
-	 * is not one mapped from another domain.
-	 * This check is for debug only, and should not go to production build
-	 */
-		unsigned long bfn = PHYS_PFN(dma_to_phys(dev, handle));
-		BUG_ON (!page_is_ram(bfn));
-#endif
-		return xen_get_dma_ops(dev)->get_sgtable(dev, sgt, cpu_addr,
-							   handle, size, attrs);
-	}
-#endif
-	return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size);
-}
-
-static int xen_swiotlb_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
-	return dma_addr == XEN_SWIOTLB_ERROR_CODE;
+	return xen_phys_to_dma(hwdev, default_swiotlb_limit()) <= mask;
 }
 
 const struct dma_map_ops xen_swiotlb_dma_ops = {
+#ifdef CONFIG_X86
 	.alloc = xen_swiotlb_alloc_coherent,
 	.free = xen_swiotlb_free_coherent,
+#else
+	.alloc = dma_direct_alloc,
+	.free = dma_direct_free,
+#endif
 	.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
 	.sync_single_for_device = xen_swiotlb_sync_single_for_device,
 	.sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
 	.sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
-	.map_sg = xen_swiotlb_map_sg_attrs,
-	.unmap_sg = xen_swiotlb_unmap_sg_attrs,
-	.map_page = xen_swiotlb_map_page,
-	.unmap_page = xen_swiotlb_unmap_page,
+	.map_sg = xen_swiotlb_map_sg,
+	.unmap_sg = xen_swiotlb_unmap_sg,
+	.map_phys = xen_swiotlb_map_phys,
+	.unmap_phys = xen_swiotlb_unmap_phys,
 	.dma_supported = xen_swiotlb_dma_supported,
-	.mmap = xen_swiotlb_dma_mmap,
-	.get_sgtable = xen_swiotlb_get_sgtable,
-	.mapping_error	= xen_swiotlb_mapping_error,
+	.mmap = dma_common_mmap,
+	.get_sgtable = dma_common_get_sgtable,
+	.alloc_pages_op = dma_common_alloc_pages,
+	.free_pages = dma_common_free_pages,
+	.max_mapping_size = swiotlb_max_mapping_size,
 };