3 files changed, 69 insertions, 51 deletions

diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index e079500b17f3..de4144c24f1c 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -111,63 +111,18 @@ int arch_gnttab_init(unsigned long nr_shared)
 }
 
 #ifdef CONFIG_XEN_PVH
-#include <xen/balloon.h>
 #include <xen/events.h>
-#include <linux/slab.h>
-static int __init xlated_setup_gnttab_pages(void)
-{
-        struct page **pages;
-        xen_pfn_t *pfns;
-        void *vaddr;
-        int rc;
-        unsigned int i;
-        unsigned long nr_grant_frames = gnttab_max_grant_frames();
-
-        BUG_ON(nr_grant_frames == 0);
-        pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
-        if (!pages)
-                return -ENOMEM;
-
-        pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
-        if (!pfns) {
-                kfree(pages);
-                return -ENOMEM;
-        }
-        rc = alloc_xenballooned_pages(nr_grant_frames, pages);
-        if (rc) {
-                pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
-                        nr_grant_frames, rc);
-                kfree(pages);
-                kfree(pfns);
-                return rc;
-        }
-        for (i = 0; i < nr_grant_frames; i++)
-                pfns[i] = page_to_pfn(pages[i]);
-
-        vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL);
-        if (!vaddr) {
-                pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
-                        nr_grant_frames, rc);
-                free_xenballooned_pages(nr_grant_frames, pages);
-                kfree(pages);
-                kfree(pfns);
-                return -ENOMEM;
-        }
-        kfree(pages);
-
-        xen_auto_xlat_grant_frames.pfn = pfns;
-        xen_auto_xlat_grant_frames.count = nr_grant_frames;
-        xen_auto_xlat_grant_frames.vaddr = vaddr;
-
-        return 0;
-}
-
+#include <xen/xen-ops.h>
 static int __init xen_pvh_gnttab_setup(void)
 {
         if (!xen_pvh_domain())
                 return -ENODEV;
 
-        return xlated_setup_gnttab_pages();
+        xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
+
+        return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
+                                             &xen_auto_xlat_grant_frames.vaddr,
+                                             xen_auto_xlat_grant_frames.count);
 }
 /* Call it _before_ __gnttab_init as we need to initialize the
  * xen_auto_xlat_grant_frames first. */
diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c
index 5063c5e796b7..9692656f2fdf 100644
--- a/drivers/xen/xlate_mmu.c
+++ b/drivers/xen/xlate_mmu.c
@@ -29,6 +29,8 @@
  */
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
 
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
@@ -37,6 +39,7 @@
 #include <xen/page.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/memory.h>
+#include <xen/balloon.h>
 
 typedef void (*xen_gfn_fn_t)(unsigned long gfn, void *data);
 
@@ -185,3 +188,61 @@ int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
         return 0;
 }
 EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
+
+/**
+ * xen_xlate_map_ballooned_pages - map a new set of ballooned pages
+ * @gfns: returns the array of corresponding GFNs
+ * @virt: returns the virtual address of the mapped region
+ * @nr_grant_frames: number of GFNs
+ * @return 0 on success, error otherwise
+ *
+ * This allocates a set of ballooned pages and maps them into the
+ * kernel's address space.
+ */
+int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt,
+                                         unsigned long nr_grant_frames)
+{
+        struct page **pages;
+        xen_pfn_t *pfns;
+        void *vaddr;
+        int rc;
+        unsigned int i;
+
+        BUG_ON(nr_grant_frames == 0);
+        pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
+        if (!pages)
+                return -ENOMEM;
+
+        pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
+        if (!pfns) {
+                kfree(pages);
+                return -ENOMEM;
+        }
+        rc = alloc_xenballooned_pages(nr_grant_frames, pages);
+        if (rc) {
+                pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
+                        nr_grant_frames, rc);
+                kfree(pages);
+                kfree(pfns);
+                return rc;
+        }
+        for (i = 0; i < nr_grant_frames; i++)
+                pfns[i] = page_to_pfn(pages[i]);
+
+        vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL);
+        if (!vaddr) {
+                pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
+                        nr_grant_frames, rc);
+                free_xenballooned_pages(nr_grant_frames, pages);
+                kfree(pages);
+                kfree(pfns);
+                return -ENOMEM;
+        }
+        kfree(pages);
+
+        *gfns = pfns;
+        *virt = vaddr;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index 86abe07b20ec..072be1c29917 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -85,6 +85,8 @@ int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
                               struct page **pages);
 int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
                               int nr, struct page **pages);
+int xen_xlate_map_ballooned_pages(xen_pfn_t **pfns, void **vaddr,
+                                  unsigned long nr_grant_frames);
 
 bool xen_running_on_version_or_later(unsigned int major, unsigned int minor);