From: jbeulich@novell.com
Subject: make pinning of pgd pairs transparent to callers
Patch-mainline: obsolete

Index: head-2008-12-01/arch/x86/mm/hypervisor.c
===================================================================
--- head-2008-12-01.orig/arch/x86/mm/hypervisor.c	2008-12-01 12:13:06.000000000 +0100
+++ head-2008-12-01/arch/x86/mm/hypervisor.c	2008-12-01 12:13:22.000000000 +0100
@@ -517,26 +517,38 @@ void xen_invlpg_mask(cpumask_t *mask, un
 
 #endif /* CONFIG_SMP */
 
-void xen_pgd_pin(unsigned long ptr)
-{
-	struct mmuext_op op;
 #ifdef CONFIG_X86_64
-	op.cmd = MMUEXT_PIN_L4_TABLE;
-#elif defined(CONFIG_X86_PAE)
-	op.cmd = MMUEXT_PIN_L3_TABLE;
+#define NR_PGD_PIN_OPS 2
 #else
-	op.cmd = MMUEXT_PIN_L2_TABLE;
+#define NR_PGD_PIN_OPS 1
 #endif
-	op.arg1.mfn = pfn_to_mfn(ptr >> PAGE_SHIFT);
-	BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
+
+void xen_pgd_pin(pgd_t *pgd)
+{
+	struct mmuext_op op[NR_PGD_PIN_OPS];
+
+	op[0].cmd = MMUEXT_PIN_L3_TABLE;
+	op[0].arg1.mfn = pfn_to_mfn(__pa(pgd) >> PAGE_SHIFT);
+#ifdef CONFIG_X86_64
+	op[1].cmd = op[0].cmd = MMUEXT_PIN_L4_TABLE;
+	op[1].arg1.mfn = pfn_to_mfn(__pa(__user_pgd(pgd)) >> PAGE_SHIFT);
+#endif
+	if (HYPERVISOR_mmuext_op(op, NR_PGD_PIN_OPS, NULL, DOMID_SELF) < 0)
+		BUG();
 }
 
-void xen_pgd_unpin(unsigned long ptr)
+void xen_pgd_unpin(pgd_t *pgd)
 {
-	struct mmuext_op op;
-	op.cmd = MMUEXT_UNPIN_TABLE;
-	op.arg1.mfn = pfn_to_mfn(ptr >> PAGE_SHIFT);
-	BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
+	struct mmuext_op op[NR_PGD_PIN_OPS];
+
+	op[0].cmd = MMUEXT_UNPIN_TABLE;
+	op[0].arg1.mfn = pfn_to_mfn(__pa(pgd) >> PAGE_SHIFT);
+#ifdef CONFIG_X86_64
+	op[1].cmd = MMUEXT_UNPIN_TABLE;
+	op[1].arg1.mfn = pfn_to_mfn(__pa(__user_pgd(pgd)) >> PAGE_SHIFT);
+#endif
+	if (HYPERVISOR_mmuext_op(op, NR_PGD_PIN_OPS, NULL, DOMID_SELF) < 0)
+		BUG();
 }
 
 void xen_set_ldt(const void *ptr, unsigned int ents)
Index: head-2008-12-01/arch/x86/mm/init_64-xen.c
===================================================================
--- head-2008-12-01.orig/arch/x86/mm/init_64-xen.c	2008-12-01 12:13:13.000000000 +0100
+++ head-2008-12-01/arch/x86/mm/init_64-xen.c	2008-12-01 12:13:22.000000000 +0100
@@ -629,10 +629,8 @@ void __init xen_init_pt(void)
 	early_make_page_readonly(level1_fixmap_pgt,
 				 XENFEAT_writable_page_tables);
 
-	if (!xen_feature(XENFEAT_writable_page_tables)) {
-		xen_pgd_pin(__pa_symbol(init_level4_pgt));
-		xen_pgd_pin(__pa_symbol(__user_pgd(init_level4_pgt)));
-	}
+	if (!xen_feature(XENFEAT_writable_page_tables))
+		xen_pgd_pin(init_level4_pgt);
 }
 
 static void __init extend_init_mapping(unsigned long tables_space)
Index: head-2008-12-01/arch/x86/mm/pgtable-xen.c
===================================================================
--- head-2008-12-01.orig/arch/x86/mm/pgtable-xen.c	2008-12-01 12:13:16.000000000 +0100
+++ head-2008-12-01/arch/x86/mm/pgtable-xen.c	2008-12-01 12:13:22.000000000 +0100
@@ -347,19 +347,13 @@ static void __pgd_pin(pgd_t *pgd)
 {
 	pgd_walk(pgd, PAGE_KERNEL_RO);
 	kmap_flush_unused();
-	xen_pgd_pin(__pa(pgd)); /* kernel */
-#ifdef CONFIG_X86_64
-	xen_pgd_pin(__pa(__user_pgd(pgd))); /* user */
-#endif
+	xen_pgd_pin(pgd);
 	SetPagePinned(virt_to_page(pgd));
 }
 
 static void __pgd_unpin(pgd_t *pgd)
 {
-	xen_pgd_unpin(__pa(pgd));
-#ifdef CONFIG_X86_64
-	xen_pgd_unpin(__pa(__user_pgd(pgd)));
-#endif
+	xen_pgd_unpin(pgd);
 	pgd_walk(pgd, PAGE_KERNEL);
 	ClearPagePinned(virt_to_page(pgd));
 }
Index: head-2008-12-01/include/asm-x86/mach-xen/asm/hypervisor.h
===================================================================
--- head-2008-12-01.orig/include/asm-x86/mach-xen/asm/hypervisor.h	2008-12-01 12:13:06.000000000 +0100
+++ head-2008-12-01/include/asm-x86/mach-xen/asm/hypervisor.h	2008-12-01 12:13:22.000000000 +0100
@@ -95,8 +95,8 @@ void xen_l1_entry_update(pte_t *ptr, pte
 void xen_l2_entry_update(pmd_t *ptr, pmd_t val);
 void xen_l3_entry_update(pud_t *ptr, pud_t val); /* x86_64/PAE */
 void xen_l4_entry_update(pgd_t *ptr, int user, pgd_t val); /* x86_64 only */
-void xen_pgd_pin(unsigned long ptr);
-void xen_pgd_unpin(unsigned long ptr);
+void xen_pgd_pin(pgd_t *);
+void xen_pgd_unpin(pgd_t *);
 
 void xen_init_pgd_pin(void);