xen: refactor xen_{alloc,release}_{pt,pd}()

Signed-off-by: Mark McLoughlin <[e-mail]>
Cc: [e-mail]
Cc: Mark McLoughlin <[e-mail]>
Cc: Jeremy Fitzhardinge <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/xen/enlighten.c

···
 	make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 }
 
-static void pin_pagetable_pfn(unsigned level, unsigned long pfn)
+static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
 {
 	struct mmuext_op op;
-	op.cmd = level;
+	op.cmd = cmd;
 	op.arg1.mfn = pfn_to_mfn(pfn);
 	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
 		BUG();
···
 
 		if (!PageHighMem(page)) {
 			make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
-			pin_pagetable_pfn(level, pfn);
+			if (level == PT_PTE)
+				pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
+			else if (level == PT_PMD)
+				pin_pagetable_pfn(MMUEXT_PIN_L2_TABLE, pfn);
 		} else
 			/* make sure there are no stray mappings of
 			   this page */
···
 
 static void xen_alloc_pt(struct mm_struct *mm, u32 pfn)
 {
-	xen_alloc_ptpage(mm, pfn, MMUEXT_PIN_L1_TABLE);
+	xen_alloc_ptpage(mm, pfn, PT_PTE);
 }
 
 static void xen_alloc_pd(struct mm_struct *mm, u32 pfn)
 {
-	xen_alloc_ptpage(mm, pfn, MMUEXT_PIN_L2_TABLE);
+	xen_alloc_ptpage(mm, pfn, PT_PMD);
 }
 
 /* This should never happen until we're OK to use struct page */
-static void xen_release_pt(u32 pfn)
+static void xen_release_ptpage(u32 pfn, unsigned level)
 {
 	struct page *page = pfn_to_page(pfn);
 
···
 			make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 		}
 	}
+}
+
+static void xen_release_pt(u32 pfn)
+{
+	xen_release_ptpage(pfn, PT_PTE);
+}
+
+static void xen_release_pd(u32 pfn)
+{
+	xen_release_ptpage(pfn, PT_PMD);
 }
 
 #ifdef CONFIG_HIGHPTE
···
 	pv_mmu_ops.alloc_pt = xen_alloc_pt;
 	pv_mmu_ops.alloc_pd = xen_alloc_pd;
 	pv_mmu_ops.release_pt = xen_release_pt;
-	pv_mmu_ops.release_pd = xen_release_pt;
+	pv_mmu_ops.release_pd = xen_release_pd;
 	pv_mmu_ops.set_pte = xen_set_pte;
 
 	setup_shared_info();

arch/x86/xen/mmu.c

···
 }
 #endif	/* CONFIG_X86_PAE */
 
-enum pt_level {
-	PT_PGD,
-	PT_PUD,
-	PT_PMD,
-	PT_PTE
-};
-
 /*
   (Yet another) pagetable walker.  This one is intended for pinning a
   pagetable.  This means that it walks a pagetable and calls the

arch/x86/xen/mmu.h

···
 #include <linux/linkage.h>
 #include <asm/page.h>
 
+enum pt_level {
+	PT_PGD,
+	PT_PUD,
+	PT_PMD,
+	PT_PTE
+};
+
 /*
  * Page-directory addresses above 4GB do not fit into architectural %cr3.
  * When accessing %cr3, or equivalent field in vcpu_guest_context, guests