2 files changed, 103 insertions, 21 deletions

diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h
index 5000397134b4..1151188bcd83 100644
--- a/arch/arm/include/asm/xen/interface.h
+++ b/arch/arm/include/asm/xen/interface.h
@@ -49,6 +49,7 @@ DEFINE_GUEST_HANDLE(void);
 DEFINE_GUEST_HANDLE(uint64_t);
 DEFINE_GUEST_HANDLE(uint32_t);
 DEFINE_GUEST_HANDLE(xen_pfn_t);
+DEFINE_GUEST_HANDLE(xen_ulong_t);
 
 /* Maximum number of virtual CPUs in multi-processor guests. */
 #define MAX_VIRT_CPUS 1
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 59bcb96ac369..f28fc1ac8760 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -8,6 +8,8 @@
 #include <xen/features.h>
 #include <xen/platform_pci.h>
 #include <xen/xenbus.h>
+#include <xen/page.h>
+#include <xen/xen-ops.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <linux/interrupt.h>
@@ -17,6 +19,8 @@
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 
+#include <linux/mm.h>
+
 struct start_info _xen_start_info;
 struct start_info *xen_start_info = &_xen_start_info;
 EXPORT_SYMBOL_GPL(xen_start_info);
@@ -29,6 +33,10 @@ struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
 
 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
 
+/* These are unused until we support booting "pre-ballooned" */
+unsigned long xen_released_pages;
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
+
 /* TODO: to be removed */
 __read_mostly int xen_have_vector_callback;
 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
@@ -38,15 +46,106 @@ EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
 
 static __read_mostly int xen_events_irq = -1;
 
+/* map fgmfn of domid to lpfn in the current domain */
+static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
+			    unsigned int domid)
+{
+	int rc;
+	struct xen_add_to_physmap_range xatp = {
+		.domid = DOMID_SELF,
+		.foreign_domid = domid,
+		.size = 1,
+		.space = XENMAPSPACE_gmfn_foreign,
+	};
+	xen_ulong_t idx = fgmfn;
+	xen_pfn_t gpfn = lpfn;
+
+	set_xen_guest_handle(xatp.idxs, &idx);
+	set_xen_guest_handle(xatp.gpfns, &gpfn);
+
+	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
+	if (rc) {
+		pr_warn("Failed to map pfn to mfn rc:%d pfn:%lx mfn:%lx\n",
+			rc, lpfn, fgmfn);
+		return 1;
+	}
+	return 0;
+}
+
+struct remap_data {
+	xen_pfn_t fgmfn; /* foreign domain's gmfn */
+	pgprot_t prot;
+	domid_t  domid;
+	struct vm_area_struct *vma;
+	int index;
+	struct page **pages;
+	struct xen_remap_mfn_info *info;
+};
+
+static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
+			void *data)
+{
+	struct remap_data *info = data;
+	struct page *page = info->pages[info->index++];
+	unsigned long pfn = page_to_pfn(page);
+	pte_t pte = pfn_pte(pfn, info->prot);
+
+	if (map_foreign_page(pfn, info->fgmfn, info->domid))
+		return -EFAULT;
+	set_pte_at(info->vma->vm_mm, addr, ptep, pte);
+
+	return 0;
+}
+
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
-			       unsigned long mfn, int nr,
-			       pgprot_t prot, unsigned domid)
+			       xen_pfn_t mfn, int nr,
+			       pgprot_t prot, unsigned domid,
+			       struct page **pages)
 {
-	return -ENOSYS;
+	int err;
+	struct remap_data data;
+
+	/* TBD: Batching, current sole caller only does page at a time */
+	if (nr > 1)
+		return -EINVAL;
+
+	data.fgmfn = mfn;
+	data.prot = prot;
+	data.domid = domid;
+	data.vma = vma;
+	data.index = 0;
+	data.pages = pages;
+	err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
+				  remap_pte_fn, &data);
+	return err;
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
 
+int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
+			       int nr, struct page **pages)
+{
+	int i;
+
+	for (i = 0; i < nr; i++) {
+		struct xen_remove_from_physmap xrp;
+		unsigned long rc, pfn;
+
+		pfn = page_to_pfn(pages[i]);
+
+		xrp.domid = DOMID_SELF;
+		xrp.gpfn = pfn;
+		rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
+		if (rc) {
+			pr_warn("Failed to unmap pfn:%lx rc:%ld\n",
+				pfn, rc);
+			return rc;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);
+
 /*
  * see Documentation/devicetree/bindings/arm/xen.txt for the
  * documentation of the Xen Device Tree format.
@@ -148,21 +247,3 @@ static int __init xen_init_events(void)
 	return 0;
 }
 postcore_initcall(xen_init_events);
-
-/* XXX: only until balloon is properly working */
-int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem)
-{
-	*pages = alloc_pages(highmem ? GFP_HIGHUSER : GFP_KERNEL,
-			get_order(nr_pages));
-	if (*pages == NULL)
-		return -ENOMEM;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(alloc_xenballooned_pages);
-
-void free_xenballooned_pages(int nr_pages, struct page **pages)
-{
-	kfree(*pages);
-	*pages = NULL;
-}
-EXPORT_SYMBOL_GPL(free_xenballooned_pages);