No need to pin/unpin intermediate pagetables in x86/64 xenlinux.

Signed-off-by: Keir Fraser <keir@xensource.com>

linux-2.6-xen-sparse/arch/i386/mm/hypervisor.c

@@ -201,56 +201,6 @@ void xen_pgd_unpin(unsigned long ptr)
 	BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
 }
 
-void xen_pte_pin(unsigned long ptr)
-{
-	struct mmuext_op op;
-	op.cmd = MMUEXT_PIN_L1_TABLE;
-	op.arg1.mfn = pfn_to_mfn(ptr >> PAGE_SHIFT);
-	BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
-}
-
-void xen_pte_unpin(unsigned long ptr)
-{
-	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);
-}
-
-#ifdef CONFIG_X86_64
-void xen_pud_pin(unsigned long ptr)
-{
-	struct mmuext_op op;
-	op.cmd = MMUEXT_PIN_L3_TABLE;
-	op.arg1.mfn = pfn_to_mfn(ptr >> PAGE_SHIFT);
-	BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
-}
-
-void xen_pud_unpin(unsigned long ptr)
-{
-	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);
-}
-
-void xen_pmd_pin(unsigned long ptr)
-{
-	struct mmuext_op op;
-	op.cmd = MMUEXT_PIN_L2_TABLE;
-	op.arg1.mfn = pfn_to_mfn(ptr >> PAGE_SHIFT);
-	BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
-}
-
-void xen_pmd_unpin(unsigned long ptr)
-{
-	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);
-}
-#endif /* CONFIG_X86_64 */
-
 void xen_set_ldt(unsigned long ptr, unsigned long len)
 {
 	struct mmuext_op op;

linux-2.6-xen-sparse/arch/x86_64/mm/init-xen.c

@@ -244,7 +244,6 @@ static void set_pte_phys(unsigned long vaddr,
 	if (pud_none(*pud)) {
 		pmd = (pmd_t *) spp_getpage(); 
 		make_page_readonly(pmd, XENFEAT_writable_page_tables);
-		xen_pmd_pin(__pa(pmd));
 		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
 		if (pmd != pmd_offset(pud, 0)) {
 			printk("PAGETABLE BUG #01! %p <-> %p\n", pmd, pmd_offset(pud,0));
@@ -255,7 +254,6 @@ static void set_pte_phys(unsigned long vaddr,
 	if (pmd_none(*pmd)) {
 		pte = (pte_t *) spp_getpage();
 		make_page_readonly(pte, XENFEAT_writable_page_tables);
-		xen_pte_pin(__pa(pte));
 		set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
 		if (pte != pte_offset_kernel(pmd, 0)) {
 			printk("PAGETABLE BUG #02!\n");
@@ -297,7 +295,6 @@ static void set_pte_phys_ma(unsigned long vaddr,
 
 		pmd = (pmd_t *) spp_getpage(); 
 		make_page_readonly(pmd, XENFEAT_writable_page_tables);
-		xen_pmd_pin(__pa(pmd));
 
 		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
 
@@ -311,7 +308,6 @@ static void set_pte_phys_ma(unsigned long vaddr,
 	if (pmd_none(*pmd)) {
 		pte = (pte_t *) spp_getpage();
 		make_page_readonly(pte, XENFEAT_writable_page_tables);
-		xen_pte_pin(__pa(pte));
 
 		set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
 		if (pte != pte_offset_kernel(pmd, 0)) {
@@ -461,7 +457,6 @@ phys_pmd_init(pmd_t *pmd, unsigned long address, unsigned long end)
 		}
 		pte = pte_save;
 		early_make_page_readonly(pte, XENFEAT_writable_page_tables);
-		xen_pte_pin(pte_phys);
 		set_pmd(pmd, __pmd(pte_phys | _KERNPG_TABLE));
 	}
 }
@@ -500,7 +495,6 @@ static void __meminit phys_pud_init(pud_t *pud, unsigned long address, unsigned
 
 		pmd = alloc_static_page(&pmd_phys);
 		early_make_page_readonly(pmd, XENFEAT_writable_page_tables);
-		xen_pmd_pin(pmd_phys);
 		spin_lock(&init_mm.page_table_lock);
 		set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
 		phys_pmd_init(pmd, paddr, end);
@@ -545,9 +539,6 @@ void __init xen_init_pt(void)
 
 	xen_pgd_pin(__pa_symbol(init_level4_pgt));
 	xen_pgd_pin(__pa_symbol(init_level4_user_pgt));
-	xen_pud_pin(__pa_symbol(level3_kernel_pgt));
-	xen_pud_pin(__pa_symbol(level3_user_pgt));
-	xen_pmd_pin(__pa_symbol(level2_kernel_pgt));
 
 	set_pgd((pgd_t *)(init_level4_user_pgt + 511), 
 		mk_kernel_pgd(__pa_symbol(level3_user_pgt)));
@@ -581,7 +572,6 @@ void __init extend_init_mapping(void)
 			pte_page = alloc_static_page(&phys);
 			early_make_page_readonly(
 				pte_page, XENFEAT_writable_page_tables);
-			xen_pte_pin(phys);
 			set_pmd(pmd, __pmd(phys | _KERNPG_TABLE | _PAGE_USER));
 		} else {
 			addr = page[pmd_index(va)];
@@ -662,7 +652,6 @@ void __meminit init_memory_mapping(unsigned long start, unsigned long end)
 			pud = alloc_static_page(&pud_phys);
 			early_make_page_readonly(pud, XENFEAT_writable_page_tables);
 		}
-		xen_pud_pin(pud_phys);
 		next = start + PGDIR_SIZE;
 		if (next > end) 
 			next = end; 
@@ -943,7 +932,6 @@ void free_initmem(void)
 		ClearPageReserved(virt_to_page(addr));
 		set_page_count(virt_to_page(addr), 1);
 		memset((void *)(addr & ~(PAGE_SIZE-1)), 0xcc, PAGE_SIZE); 
-		xen_pte_unpin(__pa(addr));
 		make_page_writable(
 			__va(__pa(addr)), XENFEAT_writable_page_tables);
 		/*

linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/hypervisor.h

@@ -79,12 +79,6 @@ void xen_l3_entry_update(pud_t *ptr, pud_t val); /* x86_64/PAE */
 void xen_l4_entry_update(pgd_t *ptr, pgd_t val); /* x86_64 only */
 void xen_pgd_pin(unsigned long ptr);
 void xen_pgd_unpin(unsigned long ptr);
-void xen_pud_pin(unsigned long ptr); /* x86_64 only */
-void xen_pud_unpin(unsigned long ptr); /* x86_64 only */
-void xen_pmd_pin(unsigned long ptr); /* x86_64 only */
-void xen_pmd_unpin(unsigned long ptr); /* x86_64 only */
-void xen_pte_pin(unsigned long ptr);
-void xen_pte_unpin(unsigned long ptr);
 
 void xen_set_ldt(unsigned long ptr, unsigned long bytes);
 void xen_machphys_update(unsigned long mfn, unsigned long pfn);

linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/pgalloc.h

@@ -181,7 +181,6 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long add
 static inline void pte_free_kernel(pte_t *pte)
 {
 	BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
-        xen_pte_unpin(__pa(pte));
         make_page_writable(pte, XENFEAT_writable_page_tables);
 	free_page((unsigned long)pte); 
 }