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]

3 files changed, 274 insertions, 1 deletions

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);