Merge remote-tracking branch 'stefano/swiotlb-xen-9.1' into stable/for-linus-3.13

* stefano/swiotlb-xen-9.1:
  swiotlb-xen: fix error code returned by xen_swiotlb_map_sg_attrs
  swiotlb-xen: static inline xen_phys_to_bus, xen_bus_to_phys, xen_virt_to_bus and range_straddles_page_boundary
  grant-table: call set_phys_to_machine after mapping grant refs
  arm,arm64: do not always merge biovec if we are running on Xen
  swiotlb: print a warning when the swiotlb is full
  swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/device
  xen: introduce xen_dma_map/unmap_page and xen_dma_sync_single_for_cpu/device
  swiotlb-xen: use xen_alloc/free_coherent_pages
  xen: introduce xen_alloc/free_coherent_pages
  arm64/xen: get_dma_ops: return xen_dma_ops if we are running as xen_initial_domain
  arm/xen: get_dma_ops: return xen_dma_ops if we are running as xen_initial_domain
  swiotlb-xen: introduce xen_swiotlb_set_dma_mask
  xen/arm,arm64: enable SWIOTLB_XEN
  xen: make xen_create_contiguous_region return the dma address
  xen/x86: allow __set_phys_to_machine for autotranslate guests
  arm/xen,arm64/xen: introduce p2m
  arm64: define DMA_ERROR_CODE
  arm: make SWIOTLB available

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Conflicts:
	arch/arm/include/asm/dma-mapping.h
	drivers/xen/swiotlb-xen.c

[Conflicts arose b/c "arm: make SWIOTLB available" v8 was in Stefano's
branch, while I had v9 + Ack from Russel. I also fixed up white-space
issues]

24 files changed, 661 insertions, 49 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b08374f8fe3b..01f7013c85c7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1888,6 +1888,7 @@ config XEN
         depends on CPU_V7 && !CPU_V6
         depends on !GENERIC_ATOMIC64
         select ARM_PSCI
+        select SWIOTLB_XEN
         help
           Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
 
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 1ad2c171054b..8acfef48124a 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -11,17 +11,28 @@
 #include <asm-generic/dma-coherent.h>
 #include <asm/memory.h>
 
+#include <xen/xen.h>
+#include <asm/xen/hypervisor.h>
+
 #define DMA_ERROR_CODE  (~0)
 extern struct dma_map_ops arm_dma_ops;
 extern struct dma_map_ops arm_coherent_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
 {
         if (dev && dev->archdata.dma_ops)
                 return dev->archdata.dma_ops;
         return &arm_dma_ops;
 }
 
+static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+        if (xen_initial_domain())
+                return xen_dma_ops;
+        else
+                return __generic_dma_ops(dev);
+}
+
 static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
 {
         BUG_ON(!dev);
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index d070741b2b37..c45effc18312 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -24,9 +24,11 @@
 #ifdef __KERNEL__
 
 #include <linux/types.h>
+#include <linux/blk_types.h>
 #include <asm/byteorder.h>
 #include <asm/memory.h>
 #include <asm-generic/pci_iomap.h>
+#include <xen/xen.h>
 
 /*
  * ISA I/O bus memory addresses are 1:1 with the physical address.
@@ -372,6 +374,12 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 #define BIOVEC_MERGEABLE(vec1, vec2)    \
         ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 
+extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+                                      const struct bio_vec *vec2);
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
+        (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
+         (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
+
 #ifdef CONFIG_MMU
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
diff --git a/arch/arm/include/asm/xen/hypervisor.h b/arch/arm/include/asm/xen/hypervisor.h
index d7ab99a0c9eb..1317ee40f4df 100644
--- a/arch/arm/include/asm/xen/hypervisor.h
+++ b/arch/arm/include/asm/xen/hypervisor.h
@@ -16,4 +16,6 @@ static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
         return PARAVIRT_LAZY_NONE;
 }
 
+extern struct dma_map_ops *xen_dma_ops;
+
 #endif /* _ASM_ARM_XEN_HYPERVISOR_H */
diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h
new file mode 100644
index 000000000000..1109017499e5
--- /dev/null
+++ b/arch/arm/include/asm/xen/page-coherent.h
@@ -0,0 +1,50 @@
+#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
+#define _ASM_ARM_XEN_PAGE_COHERENT_H
+
+#include <asm/page.h>
+#include <linux/dma-attrs.h>
+#include <linux/dma-mapping.h>
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+                dma_addr_t *dma_handle, gfp_t flags,
+                struct dma_attrs *attrs)
+{
+        return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+                void *cpu_addr, dma_addr_t dma_handle,
+                struct dma_attrs *attrs)
+{
+        __generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
+}
+
+static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
+             unsigned long offset, size_t size, enum dma_data_direction dir,
+             struct dma_attrs *attrs)
+{
+        __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+}
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+                size_t size, enum dma_data_direction dir,
+                struct dma_attrs *attrs)
+{
+        if (__generic_dma_ops(hwdev)->unmap_page)
+                __generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
+}
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+        if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
+                __generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
+}
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+        if (__generic_dma_ops(hwdev)->sync_single_for_device)
+                __generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+}
+#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */
diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
index 359a7b50b158..71bb779f2761 100644
--- a/arch/arm/include/asm/xen/page.h
+++ b/arch/arm/include/asm/xen/page.h
@@ -6,12 +6,12 @@
 
 #include <linux/pfn.h>
 #include <linux/types.h>
+#include <linux/dma-mapping.h>
 
+#include <xen/xen.h>
 #include <xen/interface/grant_table.h>
 
-#define pfn_to_mfn(pfn)                 (pfn)
 #define phys_to_machine_mapping_valid(pfn) (1)
-#define mfn_to_pfn(mfn)                 (mfn)
 #define mfn_to_virt(m)                  (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 
 #define pte_mfn     pte_pfn
@@ -32,6 +32,44 @@ typedef struct xpaddr {
 
 #define INVALID_P2M_ENTRY      (~0UL)
 
+unsigned long __pfn_to_mfn(unsigned long pfn);
+unsigned long __mfn_to_pfn(unsigned long mfn);
+extern struct rb_root phys_to_mach;
+
+static inline unsigned long pfn_to_mfn(unsigned long pfn)
+{
+        unsigned long mfn;
+
+        if (phys_to_mach.rb_node != NULL) {
+                mfn = __pfn_to_mfn(pfn);
+                if (mfn != INVALID_P2M_ENTRY)
+                        return mfn;
+        }
+
+        if (xen_initial_domain())
+                return pfn;
+        else
+                return INVALID_P2M_ENTRY;
+}
+
+static inline unsigned long mfn_to_pfn(unsigned long mfn)
+{
+        unsigned long pfn;
+
+        if (phys_to_mach.rb_node != NULL) {
+                pfn = __mfn_to_pfn(mfn);
+                if (pfn != INVALID_P2M_ENTRY)
+                        return pfn;
+        }
+
+        if (xen_initial_domain())
+                return mfn;
+        else
+                return INVALID_P2M_ENTRY;
+}
+
+#define mfn_to_local_pfn(mfn) mfn_to_pfn(mfn)
+
 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 {
         unsigned offset = phys.paddr & ~PAGE_MASK;
@@ -76,11 +114,9 @@ static inline int m2p_remove_override(struct page *page, bool clear_pte)
         return 0;
 }
 
-static inline bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
-{
-        BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
-        return true;
-}
+bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn,
+                unsigned long nr_pages);
 
 static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 {
diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
index 43841033afd3..12969523414c 100644
--- a/arch/arm/xen/Makefile
+++ b/arch/arm/xen/Makefile
@@ -1 +1 @@
-obj-y           := enlighten.o hypercall.o grant-table.o
+obj-y           := enlighten.o hypercall.o grant-table.o p2m.o mm.o
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
new file mode 100644
index 000000000000..b0e77de99148
--- /dev/null
+++ b/arch/arm/xen/mm.c
@@ -0,0 +1,65 @@
+#include <linux/bootmem.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <linux/swiotlb.h>
+
+#include <xen/xen.h>
+#include <xen/interface/memory.h>
+#include <xen/swiotlb-xen.h>
+
+#include <asm/cacheflush.h>
+#include <asm/xen/page.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/interface.h>
+
+int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
+                                 unsigned int address_bits,
+                                 dma_addr_t *dma_handle)
+{
+        if (!xen_initial_domain())
+                return -EINVAL;
+
+        /* we assume that dom0 is mapped 1:1 for now */
+        *dma_handle = pstart;
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
+
+void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
+{
+        return;
+}
+EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
+
+struct dma_map_ops *xen_dma_ops;
+EXPORT_SYMBOL_GPL(xen_dma_ops);
+
+static struct dma_map_ops xen_swiotlb_dma_ops = {
+        .mapping_error = xen_swiotlb_dma_mapping_error,
+        .alloc = xen_swiotlb_alloc_coherent,
+        .free = xen_swiotlb_free_coherent,
+        .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,
+        .dma_supported = xen_swiotlb_dma_supported,
+        .set_dma_mask = xen_swiotlb_set_dma_mask,
+};
+
+int __init xen_mm_init(void)
+{
+        if (!xen_initial_domain())
+                return 0;
+        xen_swiotlb_init(1, false);
+        xen_dma_ops = &xen_swiotlb_dma_ops;
+        return 0;
+}
+arch_initcall(xen_mm_init);
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
new file mode 100644
index 000000000000..23732cdff551
--- /dev/null
+++ b/arch/arm/xen/p2m.c
@@ -0,0 +1,208 @@
+#include <linux/bootmem.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <linux/rwlock.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <linux/swiotlb.h>
+
+#include <xen/xen.h>
+#include <xen/interface/memory.h>
+#include <xen/swiotlb-xen.h>
+
+#include <asm/cacheflush.h>
+#include <asm/xen/page.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/interface.h>
+
+struct xen_p2m_entry {
+        unsigned long pfn;
+        unsigned long mfn;
+        unsigned long nr_pages;
+        struct rb_node rbnode_mach;
+        struct rb_node rbnode_phys;
+};
+
+rwlock_t p2m_lock;
+struct rb_root phys_to_mach = RB_ROOT;
+static struct rb_root mach_to_phys = RB_ROOT;
+
+static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
+{
+        struct rb_node **link = &phys_to_mach.rb_node;
+        struct rb_node *parent = NULL;
+        struct xen_p2m_entry *entry;
+        int rc = 0;
+
+        while (*link) {
+                parent = *link;
+                entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
+
+                if (new->mfn == entry->mfn)
+                        goto err_out;
+                if (new->pfn == entry->pfn)
+                        goto err_out;
+
+                if (new->pfn < entry->pfn)
+                        link = &(*link)->rb_left;
+                else
+                        link = &(*link)->rb_right;
+        }
+        rb_link_node(&new->rbnode_phys, parent, link);
+        rb_insert_color(&new->rbnode_phys, &phys_to_mach);
+        goto out;
+
+err_out:
+        rc = -EINVAL;
+        pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
+                        __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
+out:
+        return rc;
+}
+
+unsigned long __pfn_to_mfn(unsigned long pfn)
+{
+        struct rb_node *n = phys_to_mach.rb_node;
+        struct xen_p2m_entry *entry;
+        unsigned long irqflags;
+
+        read_lock_irqsave(&p2m_lock, irqflags);
+        while (n) {
+                entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
+                if (entry->pfn <= pfn &&
+                                entry->pfn + entry->nr_pages > pfn) {
+                        read_unlock_irqrestore(&p2m_lock, irqflags);
+                        return entry->mfn + (pfn - entry->pfn);
+                }
+                if (pfn < entry->pfn)
+                        n = n->rb_left;
+                else
+                        n = n->rb_right;
+        }
+        read_unlock_irqrestore(&p2m_lock, irqflags);
+
+        return INVALID_P2M_ENTRY;
+}
+EXPORT_SYMBOL_GPL(__pfn_to_mfn);
+
+static int xen_add_mach_to_phys_entry(struct xen_p2m_entry *new)
+{
+        struct rb_node **link = &mach_to_phys.rb_node;
+        struct rb_node *parent = NULL;
+        struct xen_p2m_entry *entry;
+        int rc = 0;
+
+        while (*link) {
+                parent = *link;
+                entry = rb_entry(parent, struct xen_p2m_entry, rbnode_mach);
+
+                if (new->mfn == entry->mfn)
+                        goto err_out;
+                if (new->pfn == entry->pfn)
+                        goto err_out;
+
+                if (new->mfn < entry->mfn)
+                        link = &(*link)->rb_left;
+                else
+                        link = &(*link)->rb_right;
+        }
+        rb_link_node(&new->rbnode_mach, parent, link);
+        rb_insert_color(&new->rbnode_mach, &mach_to_phys);
+        goto out;
+
+err_out:
+        rc = -EINVAL;
+        pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
+                        __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
+out:
+        return rc;
+}
+
+unsigned long __mfn_to_pfn(unsigned long mfn)
+{
+        struct rb_node *n = mach_to_phys.rb_node;
+        struct xen_p2m_entry *entry;
+        unsigned long irqflags;
+
+        read_lock_irqsave(&p2m_lock, irqflags);
+        while (n) {
+                entry = rb_entry(n, struct xen_p2m_entry, rbnode_mach);
+                if (entry->mfn <= mfn &&
+                                entry->mfn + entry->nr_pages > mfn) {
+                        read_unlock_irqrestore(&p2m_lock, irqflags);
+                        return entry->pfn + (mfn - entry->mfn);
+                }
+                if (mfn < entry->mfn)
+                        n = n->rb_left;
+                else
+                        n = n->rb_right;
+        }
+        read_unlock_irqrestore(&p2m_lock, irqflags);
+
+        return INVALID_P2M_ENTRY;
+}
+EXPORT_SYMBOL_GPL(__mfn_to_pfn);
+
+bool __set_phys_to_machine_multi(unsigned long pfn,
+                unsigned long mfn, unsigned long nr_pages)
+{
+        int rc;
+        unsigned long irqflags;
+        struct xen_p2m_entry *p2m_entry;
+        struct rb_node *n = phys_to_mach.rb_node;
+
+        if (mfn == INVALID_P2M_ENTRY) {
+                write_lock_irqsave(&p2m_lock, irqflags);
+                while (n) {
+                        p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
+                        if (p2m_entry->pfn <= pfn &&
+                                        p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
+                                rb_erase(&p2m_entry->rbnode_mach, &mach_to_phys);
+                                rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
+                                write_unlock_irqrestore(&p2m_lock, irqflags);
+                                kfree(p2m_entry);
+                                return true;
+                        }
+                        if (pfn < p2m_entry->pfn)
+                                n = n->rb_left;
+                        else
+                                n = n->rb_right;
+                }
+                write_unlock_irqrestore(&p2m_lock, irqflags);
+                return true;
+        }
+
+        p2m_entry = kzalloc(sizeof(struct xen_p2m_entry), GFP_NOWAIT);
+        if (!p2m_entry) {
+                pr_warn("cannot allocate xen_p2m_entry\n");
+                return false;
+        }
+        p2m_entry->pfn = pfn;
+        p2m_entry->nr_pages = nr_pages;
+        p2m_entry->mfn = mfn;
+
+        write_lock_irqsave(&p2m_lock, irqflags);
+        if ((rc = xen_add_phys_to_mach_entry(p2m_entry) < 0) ||
+                (rc = xen_add_mach_to_phys_entry(p2m_entry) < 0)) {
+                write_unlock_irqrestore(&p2m_lock, irqflags);
+                return false;
+        }
+        write_unlock_irqrestore(&p2m_lock, irqflags);
+        return true;
+}
+EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
+
+bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+        return __set_phys_to_machine_multi(pfn, mfn, 1);
+}
+EXPORT_SYMBOL_GPL(__set_phys_to_machine);
+
+int p2m_init(void)
+{
+        rwlock_init(&p2m_lock);
+        return 0;
+}
+arch_initcall(p2m_init);
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c04454876bcb..04ffafb6fbe9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -211,6 +211,7 @@ config XEN_DOM0
 config XEN
         bool "Xen guest support on ARM64 (EXPERIMENTAL)"
         depends on ARM64 && OF
+        select SWIOTLB_XEN
         help
           Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
 
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 8d1810001aef..fd0c0c0e447a 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -23,11 +23,15 @@
 
 #include <asm-generic/dma-coherent.h>
 
+#include <xen/xen.h>
+#include <asm/xen/hypervisor.h>
+
 #define ARCH_HAS_DMA_GET_REQUIRED_MASK
 
+#define DMA_ERROR_CODE  (~(dma_addr_t)0)
 extern struct dma_map_ops *dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
 {
         if (unlikely(!dev) || !dev->archdata.dma_ops)
                 return dma_ops;
@@ -35,6 +39,14 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
                 return dev->archdata.dma_ops;
 }
 
+static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+        if (xen_initial_domain())
+                return xen_dma_ops;
+        else
+                return __generic_dma_ops(dev);
+}
+
 #include <asm-generic/dma-mapping-common.h>
 
 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 1d12f89140ba..c163287b9871 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -22,11 +22,14 @@
 #ifdef __KERNEL__
 
 #include <linux/types.h>
+#include <linux/blk_types.h>
 
 #include <asm/byteorder.h>
 #include <asm/barrier.h>
 #include <asm/pgtable.h>
 
+#include <xen/xen.h>
+
 /*
  * Generic IO read/write.  These perform native-endian accesses.
  */
@@ -263,5 +266,11 @@ extern int devmem_is_allowed(unsigned long pfn);
  */
 #define xlate_dev_kmem_ptr(p)   p
 
+extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+                                      const struct bio_vec *vec2);
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)                               \
+        (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&                         \
+         (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
+
 #endif  /* __KERNEL__ */
 #endif  /* __ASM_IO_H */
diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
new file mode 100644
index 000000000000..2820f1a6eebe
--- /dev/null
+++ b/arch/arm64/include/asm/xen/page-coherent.h
@@ -0,0 +1,47 @@
+#ifndef _ASM_ARM64_XEN_PAGE_COHERENT_H
+#define _ASM_ARM64_XEN_PAGE_COHERENT_H
+
+#include <asm/page.h>
+#include <linux/dma-attrs.h>
+#include <linux/dma-mapping.h>
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+                dma_addr_t *dma_handle, gfp_t flags,
+                struct dma_attrs *attrs)
+{
+        return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+                void *cpu_addr, dma_addr_t dma_handle,
+                struct dma_attrs *attrs)
+{
+        __generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
+}
+
+static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
+             unsigned long offset, size_t size, enum dma_data_direction dir,
+             struct dma_attrs *attrs)
+{
+        __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+}
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+                size_t size, enum dma_data_direction dir,
+                struct dma_attrs *attrs)
+{
+        __generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
+}
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+        __generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
+}
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+        __generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+}
+#endif /* _ASM_ARM64_XEN_PAGE_COHERENT_H */
diff --git a/arch/arm64/xen/Makefile b/arch/arm64/xen/Makefile
index be240404ba96..74a8d87e542b 100644
--- a/arch/arm64/xen/Makefile
+++ b/arch/arm64/xen/Makefile
@@ -1,2 +1,2 @@
-xen-arm-y       += $(addprefix ../../arm/xen/, enlighten.o grant-table.o)
+xen-arm-y       += $(addprefix ../../arm/xen/, enlighten.o grant-table.o p2m.o mm.o)
 obj-y           := xen-arm.o hypercall.o
diff --git a/arch/ia64/include/asm/xen/page-coherent.h b/arch/ia64/include/asm/xen/page-coherent.h
new file mode 100644
index 000000000000..96e42f97fa1f
--- /dev/null
+++ b/arch/ia64/include/asm/xen/page-coherent.h
@@ -0,0 +1,38 @@
+#ifndef _ASM_IA64_XEN_PAGE_COHERENT_H
+#define _ASM_IA64_XEN_PAGE_COHERENT_H
+
+#include <asm/page.h>
+#include <linux/dma-attrs.h>
+#include <linux/dma-mapping.h>
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+                dma_addr_t *dma_handle, gfp_t flags,
+                struct dma_attrs *attrs)
+{
+        void *vstart = (void*)__get_free_pages(flags, get_order(size));
+        *dma_handle = virt_to_phys(vstart);
+        return vstart;
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+                void *cpu_addr, dma_addr_t dma_handle,
+                struct dma_attrs *attrs)
+{
+        free_pages((unsigned long) cpu_addr, get_order(size));
+}
+
+static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
+             unsigned long offset, size_t size, enum dma_data_direction dir,
+             struct dma_attrs *attrs) { }
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+                size_t size, enum dma_data_direction dir,
+                struct dma_attrs *attrs) { }
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir) { }
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir) { }
+
+#endif /* _ASM_IA64_XEN_PAGE_COHERENT_H */
diff --git a/arch/x86/include/asm/xen/page-coherent.h b/arch/x86/include/asm/xen/page-coherent.h
new file mode 100644
index 000000000000..7f02fe4e2c7b
--- /dev/null
+++ b/arch/x86/include/asm/xen/page-coherent.h
@@ -0,0 +1,38 @@
+#ifndef _ASM_X86_XEN_PAGE_COHERENT_H
+#define _ASM_X86_XEN_PAGE_COHERENT_H
+
+#include <asm/page.h>
+#include <linux/dma-attrs.h>
+#include <linux/dma-mapping.h>
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+                dma_addr_t *dma_handle, gfp_t flags,
+                struct dma_attrs *attrs)
+{
+        void *vstart = (void*)__get_free_pages(flags, get_order(size));
+        *dma_handle = virt_to_phys(vstart);
+        return vstart;
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+                void *cpu_addr, dma_addr_t dma_handle,
+                struct dma_attrs *attrs)
+{
+        free_pages((unsigned long) cpu_addr, get_order(size));
+}
+
+static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
+             unsigned long offset, size_t size, enum dma_data_direction dir,
+             struct dma_attrs *attrs) { }
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+                size_t size, enum dma_data_direction dir,
+                struct dma_attrs *attrs) { }
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir) { }
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir) { }
+
+#endif /* _ASM_X86_XEN_PAGE_COHERENT_H */
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index c9631e73a090..b3f36369e667 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2328,12 +2328,14 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
         return success;
 }
 
-int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
-                                 unsigned int address_bits)
+int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
+                                 unsigned int address_bits,
+                                 dma_addr_t *dma_handle)
 {
         unsigned long *in_frames = discontig_frames, out_frame;
         unsigned long  flags;
         int            success;
+        unsigned long vstart = (unsigned long)phys_to_virt(pstart);
 
         /*
          * Currently an auto-translated guest will not perform I/O, nor will
@@ -2368,15 +2370,17 @@ int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
 
         spin_unlock_irqrestore(&xen_reservation_lock, flags);
 
+        *dma_handle = virt_to_machine(vstart).maddr;
         return success ? 0 : -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
 
-void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order)
+void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
 {
         unsigned long *out_frames = discontig_frames, in_frame;
         unsigned long  flags;
         int success;
+        unsigned long vstart;
 
         if (xen_feature(XENFEAT_auto_translated_physmap))
                 return;
@@ -2384,6 +2388,7 @@ void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order)
         if (unlikely(order > MAX_CONTIG_ORDER))
                 return;
 
+        vstart = (unsigned long)phys_to_virt(pstart);
         memset((void *) vstart, 0, PAGE_SIZE << order);
 
         spin_lock_irqsave(&xen_reservation_lock, flags);
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index a61c7d5811be..2ae8699e8767 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -799,10 +799,10 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 {
         unsigned topidx, mididx, idx;
 
-        if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
-                BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
+        /* don't track P2M changes in autotranslate guests */
+        if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
                 return true;
-        }
+
         if (unlikely(pfn >= MAX_P2M_PFN)) {
                 BUG_ON(mfn != INVALID_P2M_ENTRY);
                 return true;
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 23eae5cb69c2..c794ea182140 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -140,7 +140,6 @@ config XEN_GRANT_DEV_ALLOC
 
 config SWIOTLB_XEN
         def_bool y
-        depends on PCI && X86
         select SWIOTLB
 
 config XEN_TMEM
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index c4d2298893b1..62ccf5424ba8 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -49,6 +49,7 @@
 #include <xen/grant_table.h>
 #include <xen/interface/memory.h>
 #include <xen/hvc-console.h>
+#include <xen/swiotlb-xen.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/interface.h>
 
@@ -898,8 +899,16 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                         gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
                                                 &map_ops[i].status, __func__);
 
-        if (xen_feature(XENFEAT_auto_translated_physmap))
+        /* this is basically a nop on x86 */
+        if (xen_feature(XENFEAT_auto_translated_physmap)) {
+                for (i = 0; i < count; i++) {
+                        if (map_ops[i].status)
+                                continue;
+                        set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT,
+                                        map_ops[i].dev_bus_addr >> PAGE_SHIFT);
+                }
                 return ret;
+        }
 
         if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
                 arch_enter_lazy_mmu_mode();
@@ -942,8 +951,14 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
         if (ret)
                 return ret;
 
-        if (xen_feature(XENFEAT_auto_translated_physmap))
+        /* this is basically a nop on x86 */
+        if (xen_feature(XENFEAT_auto_translated_physmap)) {
+                for (i = 0; i < count; i++) {
+                        set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT,
+                                        INVALID_P2M_ENTRY);
+                }
                 return ret;
+        }
 
         if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
                 arch_enter_lazy_mmu_mode();
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 44af9d8577de..a224bc74b6b9 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -43,6 +43,9 @@
 #include <xen/xen-ops.h>
 #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
@@ -50,6 +53,20 @@
  * API.
  */
 
+#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
+
 static char *xen_io_tlb_start, *xen_io_tlb_end;
 static unsigned long xen_io_tlb_nslabs;
 /*
@@ -58,17 +75,17 @@ static unsigned long xen_io_tlb_nslabs;
 
 static u64 start_dma_addr;
 
-static dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
+static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
 {
         return phys_to_machine(XPADDR(paddr)).maddr;
 }
 
-static phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
+static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
 {
         return machine_to_phys(XMADDR(baddr)).paddr;
 }
 
-static dma_addr_t xen_virt_to_bus(void *address)
+static inline dma_addr_t xen_virt_to_bus(void *address)
 {
         return xen_phys_to_bus(virt_to_phys(address));
 }
@@ -91,7 +108,7 @@ static int check_pages_physically_contiguous(unsigned long pfn,
         return 1;
 }
 
-static int range_straddles_page_boundary(phys_addr_t p, size_t size)
+static inline int range_straddles_page_boundary(phys_addr_t p, size_t size)
 {
         unsigned long pfn = PFN_DOWN(p);
         unsigned int offset = p & ~PAGE_MASK;
@@ -128,6 +145,8 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
 {
         int i, rc;
         int dma_bits;
+        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;
 
@@ -137,9 +156,9 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
 
                 do {
                         rc = xen_create_contiguous_region(
-                                (unsigned long)buf + (i << IO_TLB_SHIFT),
+                                p + (i << IO_TLB_SHIFT),
                                 get_order(slabs << IO_TLB_SHIFT),
-                                dma_bits);
+                                dma_bits, &dma_handle);
                 } while (rc && dma_bits++ < max_dma_bits);
                 if (rc)
                         return rc;
@@ -265,7 +284,6 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
         void *ret;
         int order = get_order(size);
         u64 dma_mask = DMA_BIT_MASK(32);
-        unsigned long vstart;
         phys_addr_t phys;
         dma_addr_t dev_addr;
 
@@ -280,8 +298,12 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
         if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret))
                 return ret;
 
-        vstart = __get_free_pages(flags, order);
-        ret = (void *)vstart;
+        /* 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);
 
         if (!ret)
                 return ret;
@@ -289,18 +311,21 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
         if (hwdev && hwdev->coherent_dma_mask)
                 dma_mask = dma_alloc_coherent_mask(hwdev, flags);
 
-        phys = virt_to_phys(ret);
+        /* 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(vstart, order,
-                                                 fls64(dma_mask)) != 0) {
-                        free_pages(vstart, order);
+                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;
                 }
-                *dma_handle = virt_to_machine(ret).maddr;
         }
         memset(ret, 0, size);
         return ret;
@@ -321,13 +346,15 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
         if (hwdev && hwdev->coherent_dma_mask)
                 dma_mask = hwdev->coherent_dma_mask;
 
-        phys = virt_to_phys(vaddr);
+        /* 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 (((dev_addr + size - 1 > dma_mask)) ||
             range_straddles_page_boundary(phys, size))
-                xen_destroy_contiguous_region((unsigned long)vaddr, order);
+                xen_destroy_contiguous_region(phys, order);
 
-        free_pages((unsigned long)vaddr, order);
+        xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
 }
 EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent);
 
@@ -354,8 +381,13 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
          * buffering it.
          */
         if (dma_capable(dev, dev_addr, size) &&
-            !range_straddles_page_boundary(phys, size) && !swiotlb_force)
+            !range_straddles_page_boundary(phys, size) && !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, offset, size, dir, attrs);
                 return dev_addr;
+        }
 
         /*
          * Oh well, have to allocate and map a bounce buffer.
@@ -366,6 +398,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
         if (map == SWIOTLB_MAP_ERROR)
                 return DMA_ERROR_CODE;
 
+        xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
+                                        map & ~PAGE_MASK, size, dir, attrs);
         dev_addr = xen_phys_to_bus(map);
 
         /*
@@ -388,12 +422,15 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
  * 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)
+                             size_t size, enum dma_data_direction dir,
+                                 struct dma_attrs *attrs)
 {
         phys_addr_t paddr = xen_bus_to_phys(dev_addr);
 
         BUG_ON(dir == DMA_NONE);
 
+        xen_dma_unmap_page(hwdev, paddr, 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);
@@ -416,7 +453,7 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
                             size_t size, enum dma_data_direction dir,
                             struct dma_attrs *attrs)
 {
-        xen_unmap_single(hwdev, dev_addr, size, dir);
+        xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
 }
 EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page);
 
@@ -439,11 +476,15 @@ xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
 
         BUG_ON(dir == DMA_NONE);
 
+        if (target == SYNC_FOR_CPU)
+                xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir);
+
         /* NOTE: We use dev_addr here, not paddr! */
-        if (is_xen_swiotlb_buffer(dev_addr)) {
+        if (is_xen_swiotlb_buffer(dev_addr))
                 swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
-                return;
-        }
+
+        if (target == SYNC_FOR_DEVICE)
+                xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir);
 
         if (dir != DMA_FROM_DEVICE)
                 return;
@@ -506,16 +547,26 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
                                                                  sg->length,
                                                                  dir);
                         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. */
                                 xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
                                                            attrs);
                                 sg_dma_len(sgl) = 0;
-                                return DMA_ERROR_CODE;
+                                return 0;
                         }
                         sg->dma_address = xen_phys_to_bus(map);
-                } else
+                } 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),
+                                                paddr & ~PAGE_MASK,
+                                                sg->length,
+                                                dir,
+                                                attrs);
                         sg->dma_address = dev_addr;
+                }
                 sg_dma_len(sg) = sg->length;
         }
         return nelems;
@@ -537,7 +588,7 @@ 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);
+                xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs);
 
 }
 EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs);
@@ -597,3 +648,15 @@ xen_swiotlb_dma_supported(struct device *hwdev, u64 mask)
         return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask;
 }
 EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported);
+
+int
+xen_swiotlb_set_dma_mask(struct device *dev, u64 dma_mask)
+{
+        if (!dev->dma_mask || !xen_swiotlb_dma_supported(dev, dma_mask))
+                return -EIO;
+
+        *dev->dma_mask = dma_mask;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_swiotlb_set_dma_mask);
diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
index 4d81cccf1097..8b2eb93ae8ba 100644
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h
@@ -56,4 +56,6 @@ xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
 extern int
 xen_swiotlb_dma_supported(struct device *hwdev, u64 mask);
 
+extern int
+xen_swiotlb_set_dma_mask(struct device *dev, u64 dma_mask);
 #endif /* __LINUX_SWIOTLB_XEN_H */
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index d6fe062cad6b..fb2ea8f26552 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -19,10 +19,11 @@ void xen_arch_resume(void);
 int xen_setup_shutdown_event(void);
 
 extern unsigned long *xen_contiguous_bitmap;
-int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
-                                unsigned int address_bits);
+int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
+                                unsigned int address_bits,
+                                dma_addr_t *dma_handle);
 
-void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order);
+void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order);
 
 struct vm_area_struct;
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 55587060e893..e4399fa65ad6 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -505,6 +505,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
 
 not_found:
         spin_unlock_irqrestore(&io_tlb_lock, flags);
+        dev_warn(hwdev, "swiotlb buffer is full\n");
         return SWIOTLB_MAP_ERROR;
 found:
         spin_unlock_irqrestore(&io_tlb_lock, flags);