commit b4a69e9649d393a911b4e006a5362ad6db407faf
Author: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date:   Wed Feb 16 10:38:43 2011 -0500

    Revert "xen: drop all the special iomap pte paths."
    
    This reverts commit 0b56d9994ebe34df77fa156d2068ad93b7877b44.
    
    Conflicts:
    
    	arch/x86/xen/mmu.c

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index d9cc3a0..cac8386 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -637,7 +637,12 @@ static bool xen_page_pinned(void *ptr)
 	return PagePinned(page);
 }
 
-void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
+static bool xen_iomap_pte(pte_t pte)
+{
+	return pte_flags(pte) & _PAGE_IOMAP;
+}
+
+static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval)
 {
 	struct multicall_space mcs;
 	struct mmu_update *u;
@@ -649,11 +654,10 @@ void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
 	u->ptr = arbitrary_virt_to_machine(ptep).maddr;
 	u->val = pte_val_ma(pteval);
 
-	MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, domid);
+	MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_IO);
 
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
-EXPORT_SYMBOL_GPL(xen_set_domain_pte);
 
 static void xen_extend_mmu_update(const struct mmu_update *update)
 {
@@ -731,6 +735,11 @@ void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
 void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
 		    pte_t *ptep, pte_t pteval)
 {
+	if (xen_iomap_pte(pteval)) {
+		xen_set_iomap_pte(ptep, pteval);
+		goto out;
+	}
+
 	ADD_STATS(set_pte_at, 1);
 //	ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
 	ADD_STATS(set_pte_at_current, mm == current->mm);
@@ -962,6 +971,11 @@ void xen_set_pud(pud_t *ptr, pud_t val)
 
 void xen_set_pte(pte_t *ptep, pte_t pte)
 {
+	if (xen_iomap_pte(pte)) {
+		xen_set_iomap_pte(ptep, pte);
+		return;
+	}
+
 	ADD_STATS(pte_update, 1);
 //	ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
 	ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
@@ -978,6 +992,11 @@ void xen_set_pte(pte_t *ptep, pte_t pte)
 #ifdef CONFIG_X86_PAE
 void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
 {
+	if (xen_iomap_pte(pte)) {
+		xen_set_iomap_pte(ptep, pte);
+		return;
+	}
+
 	set_64bit((u64 *)ptep, native_pte_val(pte));
 }