Merge phase #2 (PAT updates) of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-v28-for-linus-phase2-B' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits)
  x86, cpa: make the kernel physical mapping initialization a two pass sequence, fix
  x86, pat: cleanups
  x86: fix pagetable init 64-bit breakage
  x86: track memtype for RAM in page struct
  x86, cpa: srlz cpa(), global flush tlb after splitting big page and before doing cpa
  x86, cpa: remove cpa pool code
  x86, cpa: no need to check alias for __set_pages_p/__set_pages_np
  x86, cpa: dont use large pages for kernel identity mapping with DEBUG_PAGEALLOC
  x86, cpa: make the kernel physical mapping initialization a two pass sequence
  x86, cpa: remove USER permission from the very early identity mapping attribute
  x86, cpa: rename PTE attribute macros for kernel direct mapping in early boot
  x86: make sure the CPA test code's use of _PAGE_UNUSED1 is obvious
  linux-next: fix x86 tree build failure
  x86: have set_memory_array_{uc,wb} coalesce memtypes, fix
  agp: enable optimized agp_alloc_pages methods
  x86: have set_memory_array_{uc,wb} coalesce memtypes.
  x86: {reverve,free}_memtype() take a physical address
  x86: fix pageattr-test
  agp: add agp_generic_destroy_pages()
  agp: generic_alloc_pages()
  ...

8 files changed, 555 insertions, 296 deletions

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index a7010c3..e835b4e 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -172,10 +172,6 @@ num_subarch_entries = (. - subarch_entries) / 4
  *
  * Note that the stack is not yet set up!
  */
-#define PTE_ATTR	0x007		/* PRESENT+RW+USER */
-#define PDE_ATTR	0x067		/* PRESENT+RW+USER+DIRTY+ACCESSED */
-#define PGD_ATTR	0x001		/* PRESENT (no other attributes) */
-
 default_entry:
 #ifdef CONFIG_X86_PAE
 
@@ -196,9 +192,9 @@ default_entry:
 	movl $pa(pg0), %edi
 	movl %edi, pa(init_pg_tables_start)
 	movl $pa(swapper_pg_pmd), %edx
-	movl $PTE_ATTR, %eax
+	movl $PTE_IDENT_ATTR, %eax
 10:
-	leal PDE_ATTR(%edi),%ecx		/* Create PMD entry */
+	leal PDE_IDENT_ATTR(%edi),%ecx		/* Create PMD entry */
 	movl %ecx,(%edx)			/* Store PMD entry */
 						/* Upper half already zero */
 	addl $8,%edx
@@ -215,7 +211,7 @@ default_entry:
 	 * End condition: we must map up to and including INIT_MAP_BEYOND_END
 	 * bytes beyond the end of our own page tables.
 	 */
-	leal (INIT_MAP_BEYOND_END+PTE_ATTR)(%edi),%ebp
+	leal (INIT_MAP_BEYOND_END+PTE_IDENT_ATTR)(%edi),%ebp
 	cmpl %ebp,%eax
 	jb 10b
 1:
@@ -224,7 +220,7 @@ default_entry:
 	movl %eax, pa(max_pfn_mapped)
 
 	/* Do early initialization of the fixmap area */
-	movl $pa(swapper_pg_fixmap)+PDE_ATTR,%eax
+	movl $pa(swapper_pg_fixmap)+PDE_IDENT_ATTR,%eax
 	movl %eax,pa(swapper_pg_pmd+0x1000*KPMDS-8)
 #else	/* Not PAE */
 
@@ -233,9 +229,9 @@ page_pde_offset = (__PAGE_OFFSET >> 20);
 	movl $pa(pg0), %edi
 	movl %edi, pa(init_pg_tables_start)
 	movl $pa(swapper_pg_dir), %edx
-	movl $PTE_ATTR, %eax
+	movl $PTE_IDENT_ATTR, %eax
 10:
-	leal PDE_ATTR(%edi),%ecx		/* Create PDE entry */
+	leal PDE_IDENT_ATTR(%edi),%ecx		/* Create PDE entry */
 	movl %ecx,(%edx)			/* Store identity PDE entry */
 	movl %ecx,page_pde_offset(%edx)		/* Store kernel PDE entry */
 	addl $4,%edx
@@ -249,7 +245,7 @@ page_pde_offset = (__PAGE_OFFSET >> 20);
 	 * bytes beyond the end of our own page tables; the +0x007 is
 	 * the attribute bits
 	 */
-	leal (INIT_MAP_BEYOND_END+PTE_ATTR)(%edi),%ebp
+	leal (INIT_MAP_BEYOND_END+PTE_IDENT_ATTR)(%edi),%ebp
 	cmpl %ebp,%eax
 	jb 10b
 	movl %edi,pa(init_pg_tables_end)
@@ -257,7 +253,7 @@ page_pde_offset = (__PAGE_OFFSET >> 20);
 	movl %eax, pa(max_pfn_mapped)
 
 	/* Do early initialization of the fixmap area */
-	movl $pa(swapper_pg_fixmap)+PDE_ATTR,%eax
+	movl $pa(swapper_pg_fixmap)+PDE_IDENT_ATTR,%eax
 	movl %eax,pa(swapper_pg_dir+0xffc)
 #endif
 	jmp 3f
@@ -634,19 +630,19 @@ ENTRY(empty_zero_page)
 	/* Page-aligned for the benefit of paravirt? */
 	.align PAGE_SIZE_asm
 ENTRY(swapper_pg_dir)
-	.long	pa(swapper_pg_pmd+PGD_ATTR),0		/* low identity map */
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR),0	/* low identity map */
 # if KPMDS == 3
-	.long	pa(swapper_pg_pmd+PGD_ATTR),0
-	.long	pa(swapper_pg_pmd+PGD_ATTR+0x1000),0
-	.long	pa(swapper_pg_pmd+PGD_ATTR+0x2000),0
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR),0
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR+0x1000),0
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR+0x2000),0
 # elif KPMDS == 2
 	.long	0,0
-	.long	pa(swapper_pg_pmd+PGD_ATTR),0
-	.long	pa(swapper_pg_pmd+PGD_ATTR+0x1000),0
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR),0
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR+0x1000),0
 # elif KPMDS == 1
 	.long	0,0
 	.long	0,0
-	.long	pa(swapper_pg_pmd+PGD_ATTR),0
+	.long	pa(swapper_pg_pmd+PGD_IDENT_ATTR),0
 # else
 #  error "Kernel PMDs should be 1, 2 or 3"
 # endif
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index db3280a..26cfdc1 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -110,7 +110,7 @@ startup_64:
 	movq	%rdi, %rax
 	shrq	$PMD_SHIFT, %rax
 	andq	$(PTRS_PER_PMD - 1), %rax
-	leaq	__PAGE_KERNEL_LARGE_EXEC(%rdi), %rdx
+	leaq	__PAGE_KERNEL_IDENT_LARGE_EXEC(%rdi), %rdx
 	leaq	level2_spare_pgt(%rip), %rbx
 	movq	%rdx, 0(%rbx, %rax, 8)
 ident_complete:
@@ -374,7 +374,7 @@ NEXT_PAGE(level2_ident_pgt)
 	/* Since I easily can, map the first 1G.
 	 * Don't set NX because code runs from these pages.
 	 */
-	PMDS(0, __PAGE_KERNEL_LARGE_EXEC, PTRS_PER_PMD)
+	PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
 
 NEXT_PAGE(level2_kernel_pgt)
 	/*
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 6b9a935..c3789bb 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -195,11 +195,30 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
 	pgd_t *pgd;
 	pmd_t *pmd;
 	pte_t *pte;
-	unsigned pages_2m = 0, pages_4k = 0;
+	unsigned pages_2m, pages_4k;
+	int mapping_iter;
+
+	/*
+	 * First iteration will setup identity mapping using large/small pages
+	 * based on use_pse, with other attributes same as set by
+	 * the early code in head_32.S
+	 *
+	 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
+	 * as desired for the kernel identity mapping.
+	 *
+	 * This two pass mechanism conforms to the TLB app note which says:
+	 *
+	 *     "Software should not write to a paging-structure entry in a way
+	 *      that would change, for any linear address, both the page size
+	 *      and either the page frame or attributes."
+	 */
+	mapping_iter = 1;
 
 	if (!cpu_has_pse)
 		use_pse = 0;
 
+repeat:
+	pages_2m = pages_4k = 0;
 	pfn = start_pfn;
 	pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
 	pgd = pgd_base + pgd_idx;
@@ -225,6 +244,13 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
 			if (use_pse) {
 				unsigned int addr2;
 				pgprot_t prot = PAGE_KERNEL_LARGE;
+				/*
+				 * first pass will use the same initial
+				 * identity mapping attribute + _PAGE_PSE.
+				 */
+				pgprot_t init_prot =
+					__pgprot(PTE_IDENT_ATTR |
+						 _PAGE_PSE);
 
 				addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
 					PAGE_OFFSET + PAGE_SIZE-1;
@@ -234,7 +260,10 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
 					prot = PAGE_KERNEL_LARGE_EXEC;
 
 				pages_2m++;
-				set_pmd(pmd, pfn_pmd(pfn, prot));
+				if (mapping_iter == 1)
+					set_pmd(pmd, pfn_pmd(pfn, init_prot));
+				else
+					set_pmd(pmd, pfn_pmd(pfn, prot));
 
 				pfn += PTRS_PER_PTE;
 				continue;
@@ -246,17 +275,43 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
 			for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
 			     pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
 				pgprot_t prot = PAGE_KERNEL;
+				/*
+				 * first pass will use the same initial
+				 * identity mapping attribute.
+				 */
+				pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
 
 				if (is_kernel_text(addr))
 					prot = PAGE_KERNEL_EXEC;
 
 				pages_4k++;
-				set_pte(pte, pfn_pte(pfn, prot));
+				if (mapping_iter == 1)
+					set_pte(pte, pfn_pte(pfn, init_prot));
+				else
+					set_pte(pte, pfn_pte(pfn, prot));
 			}
 		}
 	}
-	update_page_count(PG_LEVEL_2M, pages_2m);
-	update_page_count(PG_LEVEL_4K, pages_4k);
+	if (mapping_iter == 1) {
+		/*
+		 * update direct mapping page count only in the first
+		 * iteration.
+		 */
+		update_page_count(PG_LEVEL_2M, pages_2m);
+		update_page_count(PG_LEVEL_4K, pages_4k);
+
+		/*
+		 * local global flush tlb, which will flush the previous
+		 * mappings present in both small and large page TLB's.
+		 */
+		__flush_tlb_all();
+
+		/*
+		 * Second iteration will set the actual desired PTE attributes.
+		 */
+		mapping_iter = 2;
+		goto repeat;
+	}
 }
 
 /*
@@ -719,7 +774,7 @@ void __init setup_bootmem_allocator(void)
 	after_init_bootmem = 1;
 }
 
-static void __init find_early_table_space(unsigned long end)
+static void __init find_early_table_space(unsigned long end, int use_pse)
 {
 	unsigned long puds, pmds, ptes, tables, start;
 
@@ -729,7 +784,7 @@ static void __init find_early_table_space(unsigned long end)
 	pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 	tables += PAGE_ALIGN(pmds * sizeof(pmd_t));
 
-	if (cpu_has_pse) {
+	if (use_pse) {
 		unsigned long extra;
 
 		extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
@@ -769,12 +824,22 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	pgd_t *pgd_base = swapper_pg_dir;
 	unsigned long start_pfn, end_pfn;
 	unsigned long big_page_start;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	/*
+	 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
+	 * This will simplify cpa(), which otherwise needs to support splitting
+	 * large pages into small in interrupt context, etc.
+	 */
+	int use_pse = 0;
+#else
+	int use_pse = cpu_has_pse;
+#endif
 
 	/*
 	 * Find space for the kernel direct mapping tables.
 	 */
 	if (!after_init_bootmem)
-		find_early_table_space(end);
+		find_early_table_space(end, use_pse);
 
 #ifdef CONFIG_X86_PAE
 	set_nx();
@@ -820,7 +885,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
 	if (start_pfn < end_pfn)
 		kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
-						cpu_has_pse);
+					     use_pse);
 
 	/* tail is not big page alignment ? */
 	start_pfn = end_pfn;
@@ -983,7 +1048,6 @@ void __init mem_init(void)
 	if (boot_cpu_data.wp_works_ok < 0)
 		test_wp_bit();
 
-	cpa_init();
 	save_pg_dir();
 	zap_low_mappings();
 }
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 770536e..fb30486 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -271,7 +271,8 @@ static __ref void unmap_low_page(void *adr)
 }
 
 static unsigned long __meminit
-phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
+phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
+	      pgprot_t prot)
 {
 	unsigned pages = 0;
 	unsigned long last_map_addr = end;
@@ -289,36 +290,43 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
 			break;
 		}
 
+		/*
+		 * We will re-use the existing mapping.
+		 * Xen for example has some special requirements, like mapping
+		 * pagetable pages as RO. So assume someone who pre-setup
+		 * these mappings are more intelligent.
+		 */
 		if (pte_val(*pte))
 			continue;
 
 		if (0)
 			printk("   pte=%p addr=%lx pte=%016lx\n",
 			       pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
-		set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL));
-		last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 		pages++;
+		set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
+		last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 	}
+
 	update_page_count(PG_LEVEL_4K, pages);
 
 	return last_map_addr;
 }
 
 static unsigned long __meminit
-phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end)
+phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
+		pgprot_t prot)
 {
 	pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
 
-	return phys_pte_init(pte, address, end);
+	return phys_pte_init(pte, address, end, prot);
 }
 
 static unsigned long __meminit
 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
-			 unsigned long page_size_mask)
+	      unsigned long page_size_mask, pgprot_t prot)
 {
 	unsigned long pages = 0;
 	unsigned long last_map_addr = end;
-	unsigned long start = address;
 
 	int i = pmd_index(address);
 
@@ -326,6 +334,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 		unsigned long pte_phys;
 		pmd_t *pmd = pmd_page + pmd_index(address);
 		pte_t *pte;
+		pgprot_t new_prot = prot;
 
 		if (address >= end) {
 			if (!after_bootmem) {
@@ -339,27 +348,40 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 			if (!pmd_large(*pmd)) {
 				spin_lock(&init_mm.page_table_lock);
 				last_map_addr = phys_pte_update(pmd, address,
-								end);
+								end, prot);
 				spin_unlock(&init_mm.page_table_lock);
+				continue;
 			}
-			/* Count entries we're using from level2_ident_pgt */
-			if (start == 0)
-				pages++;
-			continue;
+			/*
+			 * If we are ok with PG_LEVEL_2M mapping, then we will
+			 * use the existing mapping,
+			 *
+			 * Otherwise, we will split the large page mapping but
+			 * use the same existing protection bits except for
+			 * large page, so that we don't violate Intel's TLB
+			 * Application note (317080) which says, while changing
+			 * the page sizes, new and old translations should
+			 * not differ with respect to page frame and
+			 * attributes.
+			 */
+			if (page_size_mask & (1 << PG_LEVEL_2M))
+				continue;
+			new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 		}
 
 		if (page_size_mask & (1<<PG_LEVEL_2M)) {
 			pages++;
 			spin_lock(&init_mm.page_table_lock);
 			set_pte((pte_t *)pmd,
-				pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
+				pfn_pte(address >> PAGE_SHIFT,
+					__pgprot(pgprot_val(prot) | _PAGE_PSE)));
 			spin_unlock(&init_mm.page_table_lock);
 			last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 			continue;
 		}
 
 		pte = alloc_low_page(&pte_phys);
-		last_map_addr = phys_pte_init(pte, address, end);
+		last_map_addr = phys_pte_init(pte, address, end, new_prot);
 		unmap_low_page(pte);
 
 		spin_lock(&init_mm.page_table_lock);
@@ -372,12 +394,12 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 
 static unsigned long __meminit
 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
-			 unsigned long page_size_mask)
+		unsigned long page_size_mask, pgprot_t prot)
 {
 	pmd_t *pmd = pmd_offset(pud, 0);
 	unsigned long last_map_addr;
 
-	last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask);
+	last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
 	__flush_tlb_all();
 	return last_map_addr;
 }
@@ -394,6 +416,7 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 		unsigned long pmd_phys;
 		pud_t *pud = pud_page + pud_index(addr);
 		pmd_t *pmd;
+		pgprot_t prot = PAGE_KERNEL;
 
 		if (addr >= end)
 			break;
@@ -405,10 +428,26 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 		}
 
 		if (pud_val(*pud)) {
-			if (!pud_large(*pud))
+			if (!pud_large(*pud)) {
 				last_map_addr = phys_pmd_update(pud, addr, end,
-							 page_size_mask);
-			continue;
+							 page_size_mask, prot);
+				continue;
+			}
+			/*
+			 * If we are ok with PG_LEVEL_1G mapping, then we will
+			 * use the existing mapping.
+			 *
+			 * Otherwise, we will split the gbpage mapping but use
+			 * the same existing protection  bits except for large
+			 * page, so that we don't violate Intel's TLB
+			 * Application note (317080) which says, while changing
+			 * the page sizes, new and old translations should
+			 * not differ with respect to page frame and
+			 * attributes.
+			 */
+			if (page_size_mask & (1 << PG_LEVEL_1G))
+				continue;
+			prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 		}
 
 		if (page_size_mask & (1<<PG_LEVEL_1G)) {
@@ -422,7 +461,8 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 		}
 
 		pmd = alloc_low_page(&pmd_phys);
-		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask);
+		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
+					      prot);
 		unmap_low_page(pmd);
 
 		spin_lock(&init_mm.page_table_lock);
@@ -430,6 +470,7 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 		spin_unlock(&init_mm.page_table_lock);
 	}
 	__flush_tlb_all();
+
 	update_page_count(PG_LEVEL_1G, pages);
 
 	return last_map_addr;
@@ -446,13 +487,14 @@ phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
 	return phys_pud_init(pud, addr, end, page_size_mask);
 }
 
-static void __init find_early_table_space(unsigned long end)
+static void __init find_early_table_space(unsigned long end, int use_pse,
+					  int use_gbpages)
 {
 	unsigned long puds, pmds, ptes, tables, start;
 
 	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
 	tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
-	if (direct_gbpages) {
+	if (use_gbpages) {
 		unsigned long extra;
 		extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
 		pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
@@ -460,7 +502,7 @@ static void __init find_early_table_space(unsigned long end)
 		pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 	tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
 
-	if (cpu_has_pse) {
+	if (use_pse) {
 		unsigned long extra;
 		extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
 		ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
@@ -528,6 +570,7 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start,
 		pgd_populate(&init_mm, pgd, __va(pud_phys));
 		spin_unlock(&init_mm.page_table_lock);
 	}
+	__flush_tlb_all();
 
 	return last_map_addr;
 }
@@ -571,6 +614,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 
 	struct map_range mr[NR_RANGE_MR];
 	int nr_range, i;
+	int use_pse, use_gbpages;
 
 	printk(KERN_INFO "init_memory_mapping\n");
 
@@ -584,9 +628,21 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	if (!after_bootmem)
 		init_gbpages();
 
-	if (direct_gbpages)
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	/*
+	 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
+	 * This will simplify cpa(), which otherwise needs to support splitting
+	 * large pages into small in interrupt context, etc.
+	 */
+	use_pse = use_gbpages = 0;
+#else
+	use_pse = cpu_has_pse;
+	use_gbpages = direct_gbpages;
+#endif
+
+	if (use_gbpages)
 		page_size_mask |= 1 << PG_LEVEL_1G;
-	if (cpu_has_pse)
+	if (use_pse)
 		page_size_mask |= 1 << PG_LEVEL_2M;
 
 	memset(mr, 0, sizeof(mr));
@@ -647,7 +703,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 			 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
 
 	if (!after_bootmem)
-		find_early_table_space(end);
+		find_early_table_space(end, use_pse, use_gbpages);
 
 	for (i = 0; i < nr_range; i++)
 		last_map_addr = kernel_physical_mapping_init(
@@ -806,8 +862,6 @@ void __init mem_init(void)
 		reservedpages << (PAGE_SHIFT-10),
 		datasize >> 10,
 		initsize >> 10);
-
-	cpa_init();
 }
 
 void free_init_pages(char *what, unsigned long begin, unsigned long end)
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index cac6da5..6ab3196 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -83,6 +83,25 @@ int page_is_ram(unsigned long pagenr)
 	return 0;
 }
 
+int pagerange_is_ram(unsigned long start, unsigned long end)
+{
+	int ram_page = 0, not_rampage = 0;
+	unsigned long page_nr;
+
+	for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
+	     ++page_nr) {
+		if (page_is_ram(page_nr))
+			ram_page = 1;
+		else
+			not_rampage = 1;
+
+		if (ram_page == not_rampage)
+			return -1;
+	}
+
+	return ram_page;
+}
+
 /*
  * Fix up the linear direct mapping of the kernel to avoid cache attribute
  * conflicts.
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
index d4aa503..e1d1069 100644
--- a/arch/x86/mm/pageattr-test.c
+++ b/arch/x86/mm/pageattr-test.c
@@ -32,7 +32,7 @@ enum {
 	GPS			= (1<<30)
 };
 
-#define PAGE_TESTBIT	__pgprot(_PAGE_UNUSED1)
+#define PAGE_CPA_TEST	__pgprot(_PAGE_CPA_TEST)
 
 static int pte_testbit(pte_t pte)
 {
@@ -118,6 +118,7 @@ static int pageattr_test(void)
 	unsigned int level;
 	int i, k;
 	int err;
+	unsigned long test_addr;
 
 	if (print)
 		printk(KERN_INFO "CPA self-test:\n");
@@ -172,7 +173,8 @@ static int pageattr_test(void)
 			continue;
 		}
 
-		err = change_page_attr_set(addr[i], len[i], PAGE_TESTBIT);
+		test_addr = addr[i];
+		err = change_page_attr_set(&test_addr, len[i], PAGE_CPA_TEST, 0);
 		if (err < 0) {
 			printk(KERN_ERR "CPA %d failed %d\n", i, err);
 			failed++;
@@ -204,7 +206,8 @@ static int pageattr_test(void)
 			failed++;
 			continue;
 		}
-		err = change_page_attr_clear(addr[i], len[i], PAGE_TESTBIT);
+		test_addr = addr[i];
+		err = change_page_attr_clear(&test_addr, len[i], PAGE_CPA_TEST, 0);
 		if (err < 0) {
 			printk(KERN_ERR "CPA reverting failed: %d\n", err);
 			failed++;
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 898fad6..a9ec89c 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -25,15 +25,27 @@
  * The current flushing context - we pass it instead of 5 arguments:
  */
 struct cpa_data {
-	unsigned long	vaddr;
+	unsigned long	*vaddr;
 	pgprot_t	mask_set;
 	pgprot_t	mask_clr;
 	int		numpages;
-	int		flushtlb;
+	int		flags;
 	unsigned long	pfn;
 	unsigned	force_split : 1;
+	int		curpage;
 };
 
+/*
+ * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings)
+ * using cpa_lock. So that we don't allow any other cpu, with stale large tlb
+ * entries change the page attribute in parallel to some other cpu
+ * splitting a large page entry along with changing the attribute.
+ */
+static DEFINE_SPINLOCK(cpa_lock);
+
+#define CPA_FLUSHTLB 1
+#define CPA_ARRAY 2
+
 #ifdef CONFIG_PROC_FS
 static unsigned long direct_pages_count[PG_LEVEL_NUM];
 
@@ -190,6 +202,41 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
 	}
 }
 
+static void cpa_flush_array(unsigned long *start, int numpages, int cache)
+{
+	unsigned int i, level;
+	unsigned long *addr;
+
+	BUG_ON(irqs_disabled());
+
+	on_each_cpu(__cpa_flush_range, NULL, 1);
+
+	if (!cache)
+		return;
+
+	/* 4M threshold */
+	if (numpages >= 1024) {
+		if (boot_cpu_data.x86_model >= 4)
+			wbinvd();
+		return;
+	}
+	/*
+	 * We only need to flush on one CPU,
+	 * clflush is a MESI-coherent instruction that
+	 * will cause all other CPUs to flush the same
+	 * cachelines:
+	 */
+	for (i = 0, addr = start; i < numpages; i++, addr++) {
+		pte_t *pte = lookup_address(*addr, &level);
+
+		/*
+		 * Only flush present addresses:
+		 */
+		if (pte && (pte_val(*pte) & _PAGE_PRESENT))
+			clflush_cache_range((void *) *addr, PAGE_SIZE);
+	}
+}
+
 /*
  * Certain areas of memory on x86 require very specific protection flags,
  * for example the BIOS area or kernel text. Callers don't always get this
@@ -398,7 +445,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
 		 */
 		new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
 		__set_pmd_pte(kpte, address, new_pte);
-		cpa->flushtlb = 1;
+		cpa->flags |= CPA_FLUSHTLB;
 		do_split = 0;
 	}
 
@@ -408,84 +455,6 @@ out_unlock:
 	return do_split;
 }
 
-static LIST_HEAD(page_pool);
-static unsigned long pool_size, pool_pages, pool_low;
-static unsigned long pool_used, pool_failed;
-
-static void cpa_fill_pool(struct page **ret)
-{
-	gfp_t gfp = GFP_KERNEL;
-	unsigned long flags;
-	struct page *p;
-
-	/*
-	 * Avoid recursion (on debug-pagealloc) and also signal
-	 * our priority to get to these pagetables:
-	 */
-	if (current->flags & PF_MEMALLOC)
-		return;
-	current->flags |= PF_MEMALLOC;
-
-	/*
-	 * Allocate atomically from atomic contexts:
-	 */
-	if (in_atomic() || irqs_disabled() || debug_pagealloc)
-		gfp =  GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
-
-	while (pool_pages < pool_size || (ret && !*ret)) {
-		p = alloc_pages(gfp, 0);
-		if (!p) {
-			pool_failed++;
-			break;
-		}
-		/*
-		 * If the call site needs a page right now, provide it:
-		 */
-		if (ret && !*ret) {
-			*ret = p;
-			continue;
-		}
-		spin_lock_irqsave(&pgd_lock, flags);
-		list_add(&p->lru, &page_pool);
-		pool_pages++;
-		spin_unlock_irqrestore(&pgd_lock, flags);
-	}
-
-	current->flags &= ~PF_MEMALLOC;
-}
-
-#define SHIFT_MB		(20 - PAGE_SHIFT)
-#define ROUND_MB_GB		((1 << 10) - 1)
-#define SHIFT_MB_GB		10
-#define POOL_PAGES_PER_GB	16
-
-void __init cpa_init(void)
-{
-	struct sysinfo si;
-	unsigned long gb;
-
-	si_meminfo(&si);
-	/*
-	 * Calculate the number of pool pages:
-	 *
-	 * Convert totalram (nr of pages) to MiB and round to the next
-	 * GiB. Shift MiB to Gib and multiply the result by
-	 * POOL_PAGES_PER_GB:
-	 */
-	if (debug_pagealloc) {
-		gb = ((si.totalram >> SHIFT_MB) + ROUND_MB_GB) >> SHIFT_MB_GB;
-		pool_size = POOL_PAGES_PER_GB * gb;
-	} else {
-		pool_size = 1;
-	}
-	pool_low = pool_size;
-
-	cpa_fill_pool(NULL);
-	printk(KERN_DEBUG
-	       "CPA: page pool initialized %lu of %lu pages preallocated\n",
-	       pool_pages, pool_size);
-}
-
 static int split_large_page(pte_t *kpte, unsigned long address)
 {
 	unsigned long flags, pfn, pfninc = 1;
@@ -494,28 +463,15 @@ static int split_large_page(pte_t *kpte, unsigned long address)
 	pgprot_t ref_prot;
 	struct page *base;
 
-	/*
-	 * Get a page from the pool. The pool list is protected by the
-	 * pgd_lock, which we have to take anyway for the split
-	 * operation:
-	 */
-	spin_lock_irqsave(&pgd_lock, flags);
-	if (list_empty(&page_pool)) {
-		spin_unlock_irqrestore(&pgd_lock, flags);
-		base = NULL;
-		cpa_fill_pool(&base);
-		if (!base)
-			return -ENOMEM;
-		spin_lock_irqsave(&pgd_lock, flags);
-	} else {
-		base = list_first_entry(&page_pool, struct page, lru);
-		list_del(&base->lru);
-		pool_pages--;
-
-		if (pool_pages < pool_low)
-			pool_low = pool_pages;
-	}
+	if (!debug_pagealloc)
+		spin_unlock(&cpa_lock);
+	base = alloc_pages(GFP_KERNEL, 0);
+	if (!debug_pagealloc)
+		spin_lock(&cpa_lock);
+	if (!base)
+		return -ENOMEM;
 
+	spin_lock_irqsave(&pgd_lock, flags);
 	/*
 	 * Check for races, another CPU might have split this page
 	 * up for us already:
@@ -572,11 +528,8 @@ out_unlock:
 	 * If we dropped out via the lookup_address check under
 	 * pgd_lock then stick the page back into the pool:
 	 */
-	if (base) {
-		list_add(&base->lru, &page_pool);
-		pool_pages++;
-	} else
-		pool_used++;
+	if (base)
+		__free_page(base);
 	spin_unlock_irqrestore(&pgd_lock, flags);
 
 	return 0;
@@ -584,11 +537,16 @@ out_unlock:
 
 static int __change_page_attr(struct cpa_data *cpa, int primary)
 {
-	unsigned long address = cpa->vaddr;
+	unsigned long address;
 	int do_split, err;
 	unsigned int level;
 	pte_t *kpte, old_pte;
 
+	if (cpa->flags & CPA_ARRAY)
+		address = cpa->vaddr[cpa->curpage];
+	else
+		address = *cpa->vaddr;
+
 repeat:
 	kpte = lookup_address(address, &level);
 	if (!kpte)
@@ -600,7 +558,7 @@ repeat:
 			return 0;
 		WARN(1, KERN_WARNING "CPA: called for zero pte. "
 		       "vaddr = %lx cpa->vaddr = %lx\n", address,
-		       cpa->vaddr);
+		       *cpa->vaddr);
 		return -EINVAL;
 	}
 
@@ -626,7 +584,7 @@ repeat:
 		 */
 		if (pte_val(old_pte) != pte_val(new_pte)) {
 			set_pte_atomic(kpte, new_pte);
-			cpa->flushtlb = 1;
+			cpa->flags |= CPA_FLUSHTLB;
 		}
 		cpa->numpages = 1;
 		return 0;
@@ -650,7 +608,25 @@ repeat:
 	 */
 	err = split_large_page(kpte, address);
 	if (!err) {
-		cpa->flushtlb = 1;
+		/*
+	 	 * Do a global flush tlb after splitting the large page
+	 	 * and before we do the actual change page attribute in the PTE.
+	 	 *
+	 	 * With out this, we violate the TLB application note, that says
+	 	 * "The TLBs may contain both ordinary and large-page
+		 *  translations for a 4-KByte range of linear addresses. This
+		 *  may occur if software modifies the paging structures so that
+		 *  the page size used for the address range changes. If the two
+		 *  translations differ with respect to page frame or attributes
+		 *  (e.g., permissions), processor behavior is undefined and may
+		 *  be implementation-specific."
+	 	 *
+	 	 * We do this global tlb flush inside the cpa_lock, so that we
+		 * don't allow any other cpu, with stale tlb entries change the
+		 * page attribute in parallel, that also falls into the
+		 * just split large page entry.
+	 	 */
+		flush_tlb_all();
 		goto repeat;
 	}
 
@@ -663,6 +639,7 @@ static int cpa_process_alias(struct cpa_data *cpa)
 {
 	struct cpa_data alias_cpa;
 	int ret = 0;
+	unsigned long temp_cpa_vaddr, vaddr;
 
 	if (cpa->pfn >= max_pfn_mapped)
 		return 0;
@@ -675,16 +652,24 @@ static int cpa_process_alias(struct cpa_data *cpa)
 	 * No need to redo, when the primary call touched the direct
 	 * mapping already:
 	 */
-	if (!(within(cpa->vaddr, PAGE_OFFSET,
+	if (cpa->flags & CPA_ARRAY)
+		vaddr = cpa->vaddr[cpa->curpage];
+	else
+		vaddr = *cpa->vaddr;
+
+	if (!(within(vaddr, PAGE_OFFSET,
 		    PAGE_OFFSET + (max_low_pfn_mapped << PAGE_SHIFT))
 #ifdef CONFIG_X86_64
-		|| within(cpa->vaddr, PAGE_OFFSET + (1UL<<32),
+		|| within(vaddr, PAGE_OFFSET + (1UL<<32),
 		    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))
 #endif
 	)) {
 
 		alias_cpa = *cpa;
-		alias_cpa.vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
+		temp_cpa_vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
+		alias_cpa.vaddr = &temp_cpa_vaddr;
+		alias_cpa.flags &= ~CPA_ARRAY;
+
 
 		ret = __change_page_attr_set_clr(&alias_cpa, 0);
 	}
@@ -696,7 +681,7 @@ static int cpa_process_alias(struct cpa_data *cpa)
 	 * No need to redo, when the primary call touched the high
 	 * mapping already:
 	 */
-	if (within(cpa->vaddr, (unsigned long) _text, (unsigned long) _end))
+	if (within(vaddr, (unsigned long) _text, (unsigned long) _end))
 		return 0;
 
 	/*
@@ -707,8 +692,9 @@ static int cpa_process_alias(struct cpa_data *cpa)
 		return 0;
 
 	alias_cpa = *cpa;
-	alias_cpa.vaddr =
-		(cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base;
+	temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base;
+	alias_cpa.vaddr = &temp_cpa_vaddr;
+	alias_cpa.flags &= ~CPA_ARRAY;
 
 	/*
 	 * The high mapping range is imprecise, so ignore the return value.
@@ -728,8 +714,15 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
 		 * preservation check.
 		 */
 		cpa->numpages = numpages;
+		/* for array changes, we can't use large page */
+		if (cpa->flags & CPA_ARRAY)
+			cpa->numpages = 1;
 
+		if (!debug_pagealloc)
+			spin_lock(&cpa_lock);
 		ret = __change_page_attr(cpa, checkalias);
+		if (!debug_pagealloc)
+			spin_unlock(&cpa_lock);
 		if (ret)
 			return ret;
 
@@ -746,7 +739,11 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
 		 */
 		BUG_ON(cpa->numpages > numpages);
 		numpages -= cpa->numpages;
-		cpa->vaddr += cpa->numpages * PAGE_SIZE;
+		if (cpa->flags & CPA_ARRAY)
+			cpa->curpage++;
+		else
+			*cpa->vaddr += cpa->numpages * PAGE_SIZE;
+
 	}
 	return 0;
 }
@@ -757,9 +754,9 @@ static inline int cache_attr(pgprot_t attr)
 		(_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
 }
 
-static int change_page_attr_set_clr(unsigned long addr, int numpages,
+static int change_page_attr_set_clr(unsigned long *addr, int numpages,
 				    pgprot_t mask_set, pgprot_t mask_clr,
-				    int force_split)
+				    int force_split, int array)
 {
 	struct cpa_data cpa;
 	int ret, cache, checkalias;
@@ -774,21 +771,38 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
 		return 0;
 
 	/* Ensure we are PAGE_SIZE aligned */
-	if (addr & ~PAGE_MASK) {
-		addr &= PAGE_MASK;
-		/*
-		 * People should not be passing in unaligned addresses:
-		 */
-		WARN_ON_ONCE(1);
+	if (!array) {
+		if (*addr & ~PAGE_MASK) {
+			*addr &= PAGE_MASK;
+			/*
+			 * People should not be passing in unaligned addresses:
+			 */
+			WARN_ON_ONCE(1);
+		}
+	} else {
+		int i;
+		for (i = 0; i < numpages; i++) {
+			if (addr[i] & ~PAGE_MASK) {
+				addr[i] &= PAGE_MASK;
+				WARN_ON_ONCE(1);
+			}
+		}
 	}
 
+	/* Must avoid aliasing mappings in the highmem code */
+	kmap_flush_unused();
+
 	cpa.vaddr = addr;
 	cpa.numpages = numpages;
 	cpa.mask_set = mask_set;
 	cpa.mask_clr = mask_clr;
-	cpa.flushtlb = 0;
+	cpa.flags = 0;
+	cpa.curpage = 0;
 	cpa.force_split = force_split;
 
+	if (array)
+		cpa.flags |= CPA_ARRAY;
+
 	/* No alias checking for _NX bit modifications */
 	checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
 
@@ -797,7 +811,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
 	/*
 	 * Check whether we really changed something:
 	 */
-	if (!cpa.flushtlb)
+	if (!(cpa.flags & CPA_FLUSHTLB))
 		goto out;
 
 	/*
@@ -812,27 +826,30 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
 	 * error case we fall back to cpa_flush_all (which uses
 	 * wbindv):
 	 */
-	if (!ret && cpu_has_clflush)
-		cpa_flush_range(addr, numpages, cache);
-	else
+	if (!ret && cpu_has_clflush) {
+		if (cpa.flags & CPA_ARRAY)
+			cpa_flush_array(addr, numpages, cache);
+		else
+			cpa_flush_range(*addr, numpages, cache);
+	} else
 		cpa_flush_all(cache);
 
 out:
-	cpa_fill_pool(NULL);
-
 	return ret;
 }
 
-static inline int change_page_attr_set(unsigned long addr, int numpages,
-				       pgprot_t mask)
+static inline int change_page_attr_set(unsigned long *addr, int numpages,
+				       pgprot_t mask, int array)
 {
-	return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0);
+	return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0,
+		array);
 }
 
-static inline int change_page_attr_clear(unsigned long addr, int numpages,
-					 pgprot_t mask)
+static inline int change_page_attr_clear(unsigned long *addr, int numpages,
+					 pgprot_t mask, int array)
 {
-	return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0);
+	return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0,
+		array);
 }
 
 int _set_memory_uc(unsigned long addr, int numpages)
@@ -840,8 +857,8 @@ int _set_memory_uc(unsigned long addr, int numpages)
 	/*
 	 * for now UC MINUS. see comments in ioremap_nocache()
 	 */
-	return change_page_attr_set(addr, numpages,
-				    __pgprot(_PAGE_CACHE_UC_MINUS));
+	return change_page_attr_set(&addr, numpages,
+				    __pgprot(_PAGE_CACHE_UC_MINUS), 0);
 }
 
 int set_memory_uc(unsigned long addr, int numpages)
@@ -857,10 +874,48 @@ int set_memory_uc(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_uc);
 
+int set_memory_array_uc(unsigned long *addr, int addrinarray)
+{
+	unsigned long start;
+	unsigned long end;
+	int i;
+	/*
+	 * for now UC MINUS. see comments in ioremap_nocache()
+	 */
+	for (i = 0; i < addrinarray; i++) {
+		start = __pa(addr[i]);
+		for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) {
+			if (end != __pa(addr[i + 1]))
+				break;
+			i++;
+		}
+		if (reserve_memtype(start, end, _PAGE_CACHE_UC_MINUS, NULL))
+			goto out;
+	}
+
+	return change_page_attr_set(addr, addrinarray,
+				    __pgprot(_PAGE_CACHE_UC_MINUS), 1);
+out:
+	for (i = 0; i < addrinarray; i++) {
+		unsigned long tmp = __pa(addr[i]);
+
+		if (tmp == start)
+			break;
+		for (end = tmp + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) {
+			if (end != __pa(addr[i + 1]))
+				break;
+			i++;
+		}
+		free_memtype(tmp, end);
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL(set_memory_array_uc);
+
 int _set_memory_wc(unsigned long addr, int numpages)
 {
-	return change_page_attr_set(addr, numpages,
-				    __pgprot(_PAGE_CACHE_WC));
+	return change_page_attr_set(&addr, numpages,
+				    __pgprot(_PAGE_CACHE_WC), 0);
 }
 
 int set_memory_wc(unsigned long addr, int numpages)
@@ -878,8 +933,8 @@ EXPORT_SYMBOL(set_memory_wc);
 
 int _set_memory_wb(unsigned long addr, int numpages)
 {
-	return change_page_attr_clear(addr, numpages,
-				      __pgprot(_PAGE_CACHE_MASK));
+	return change_page_attr_clear(&addr, numpages,
+				      __pgprot(_PAGE_CACHE_MASK), 0);
 }
 
 int set_memory_wb(unsigned long addr, int numpages)
@@ -890,39 +945,59 @@ int set_memory_wb(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_wb);
 
+int set_memory_array_wb(unsigned long *addr, int addrinarray)
+{
+	int i;
+
+	for (i = 0; i < addrinarray; i++) {
+		unsigned long start = __pa(addr[i]);
+		unsigned long end;
+
+		for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) {
+			if (end != __pa(addr[i + 1]))
+				break;
+			i++;
+		}
+		free_memtype(start, end);
+	}
+	return change_page_attr_clear(addr, addrinarray,
+				      __pgprot(_PAGE_CACHE_MASK), 1);
+}
+EXPORT_SYMBOL(set_memory_array_wb);
+
 int set_memory_x(unsigned long addr, int numpages)
 {
-	return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_NX));
+	return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0);
 }
 EXPORT_SYMBOL(set_memory_x);
 
 int set_memory_nx(unsigned long addr, int numpages)
 {
-	return change_page_attr_set(addr, numpages, __pgprot(_PAGE_NX));
+	return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0);
 }
 EXPORT_SYMBOL(set_memory_nx);
 
 int set_memory_ro(unsigned long addr, int numpages)
 {
-	return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_RW));
+	return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
 }
 EXPORT_SYMBOL_GPL(set_memory_ro);
 
 int set_memory_rw(unsigned long addr, int numpages)
 {
-	return change_page_attr_set(addr, numpages, __pgprot(_PAGE_RW));
+	return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
 }
 EXPORT_SYMBOL_GPL(set_memory_rw);
 
 int set_memory_np(unsigned long addr, int numpages)
 {
-	return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT));
+	return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
 }
 
 int set_memory_4k(unsigned long addr, int numpages)
 {
-	return change_page_attr_set_clr(addr, numpages, __pgprot(0),
-					__pgprot(0), 1);
+	return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
+					__pgprot(0), 1, 0);
 }
 
 int set_pages_uc(struct page *page, int numpages)
@@ -975,22 +1050,38 @@ int set_pages_rw(struct page *page, int numpages)
 
 static int __set_pages_p(struct page *page, int numpages)
 {
-	struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
+	unsigned long tempaddr = (unsigned long) page_address(page);
+	struct cpa_data cpa = { .vaddr = &tempaddr,
 				.numpages = numpages,
 				.mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
-				.mask_clr = __pgprot(0)};
+				.mask_clr = __pgprot(0),
+				.flags = 0};
 
-	return __change_page_attr_set_clr(&cpa, 1);
+	/*
+	 * No alias checking needed for setting present flag. otherwise,
+	 * we may need to break large pages for 64-bit kernel text
+	 * mappings (this adds to complexity if we want to do this from
+	 * atomic context especially). Let's keep it simple!
+	 */
+	return __change_page_attr_set_clr(&cpa, 0);
 }
 
 static int __set_pages_np(struct page *page, int numpages)
 {
-	struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
+	unsigned long tempaddr = (unsigned long) page_address(page);
+	struct cpa_data cpa = { .vaddr = &tempaddr,
 				.numpages = numpages,
 				.mask_set = __pgprot(0),
-				.mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW)};
+				.mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
+				.flags = 0};
 
-	return __change_page_attr_set_clr(&cpa, 1);
+	/*
+	 * No alias checking needed for setting not present flag. otherwise,
+	 * we may need to break large pages for 64-bit kernel text
+	 * mappings (this adds to complexity if we want to do this from
+	 * atomic context especially). Let's keep it simple!
+	 */
+	return __change_page_attr_set_clr(&cpa, 0);
 }
 
 void kernel_map_pages(struct page *page, int numpages, int enable)
@@ -1010,11 +1101,8 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
 
 	/*
 	 * The return value is ignored as the calls cannot fail.
-	 * Large pages are kept enabled at boot time, and are
-	 * split up quickly with DEBUG_PAGEALLOC. If a splitup
-	 * fails here (due to temporary memory shortage) no damage
-	 * is done because we just keep the largepage intact up
-	 * to the next attempt when it will likely be split up:
+	 * Large pages for identity mappings are not used at boot time
+	 * and hence no memory allocations during large page split.
 	 */
 	if (enable)
 		__set_pages_p(page, numpages);
@@ -1026,53 +1114,8 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
 	 * but that can deadlock->flush only current cpu:
 	 */
 	__flush_tlb_all();
-
-	/*
-	 * Try to refill the page pool here. We can do this only after
-	 * the tlb flush.
-	 */
-	cpa_fill_pool(NULL);
 }
 
-#ifdef CONFIG_DEBUG_FS
-static int dpa_show(struct seq_file *m, void *v)
-{
-	seq_puts(m, "DEBUG_PAGEALLOC\n");
-	seq_printf(m, "pool_size     : %lu\n", pool_size);
-	seq_printf(m, "pool_pages    : %lu\n", pool_pages);
-	seq_printf(m, "pool_low      : %lu\n", pool_low);
-	seq_printf(m, "pool_used     : %lu\n", pool_used);
-	seq_printf(m, "pool_failed   : %lu\n", pool_failed);
-
-	return 0;
-}
-
-static int dpa_open(struct inode *inode, struct file *filp)
-{
-	return single_open(filp, dpa_show, NULL);
-}
-
-static const struct file_operations dpa_fops = {
-	.open		= dpa_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
-static int __init debug_pagealloc_proc_init(void)
-{
-	struct dentry *de;
-
-	de = debugfs_create_file("debug_pagealloc", 0600, NULL, NULL,
-				 &dpa_fops);
-	if (!de)
-		return -ENOMEM;
-
-	return 0;
-}
-__initcall(debug_pagealloc_proc_init);
-#endif
-
 #ifdef CONFIG_HIBERNATION
 
 bool kernel_page_present(struct page *page)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 2a50e0f..738fd0f2 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -7,24 +7,24 @@
  * Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen.
  */
 
-#include <linux/mm.h>
+#include <linux/seq_file.h>
+#include <linux/bootmem.h>
+#include <linux/debugfs.h>
 #include <linux/kernel.h>
 #include <linux/gfp.h>
+#include <linux/mm.h>
 #include <linux/fs.h>
-#include <linux/bootmem.h>
-#include <linux/debugfs.h>
-#include <linux/seq_file.h>
 
-#include <asm/msr.h>
-#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
 #include <asm/processor.h>
-#include <asm/page.h>
+#include <asm/tlbflush.h>
 #include <asm/pgtable.h>
-#include <asm/pat.h>
-#include <asm/e820.h>
-#include <asm/cacheflush.h>
 #include <asm/fcntl.h>
+#include <asm/e820.h>
 #include <asm/mtrr.h>
+#include <asm/page.h>
+#include <asm/msr.h>
+#include <asm/pat.h>
 #include <asm/io.h>
 
 #ifdef CONFIG_X86_PAT
@@ -46,6 +46,7 @@ early_param("nopat", nopat);
 
 
 static int debug_enable;
+
 static int __init pat_debug_setup(char *str)
 {
 	debug_enable = 1;
@@ -145,14 +146,14 @@ static char *cattr_name(unsigned long flags)
  */
 
 struct memtype {
-	u64 start;
-	u64 end;
-	unsigned long type;
-	struct list_head nd;
+	u64			start;
+	u64			end;
+	unsigned long		type;
+	struct list_head	nd;
 };
 
 static LIST_HEAD(memtype_list);
-static DEFINE_SPINLOCK(memtype_lock); 	/* protects memtype list */
+static DEFINE_SPINLOCK(memtype_lock);	/* protects memtype list */
 
 /*
  * Does intersection of PAT memory type and MTRR memory type and returns
@@ -180,8 +181,8 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
 	return req_type;
 }
 
-static int chk_conflict(struct memtype *new, struct memtype *entry,
-			unsigned long *type)
+static int
+chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type)
 {
 	if (new->type != entry->type) {
 		if (type) {
@@ -211,6 +212,66 @@ static struct memtype *cached_entry;
 static u64 cached_start;
 
 /*
+ * For RAM pages, mark the pages as non WB memory type using
+ * PageNonWB (PG_arch_1). We allow only one set_memory_uc() or
+ * set_memory_wc() on a RAM page at a time before marking it as WB again.
+ * This is ok, because only one driver will be owning the page and
+ * doing set_memory_*() calls.
+ *
+ * For now, we use PageNonWB to track that the RAM page is being mapped
+ * as non WB. In future, we will have to use one more flag
+ * (or some other mechanism in page_struct) to distinguish between
+ * UC and WC mapping.
+ */
+static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type,
+				  unsigned long *new_type)
+{
+	struct page *page;
+	u64 pfn, end_pfn;
+
+	for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
+		page = pfn_to_page(pfn);
+		if (page_mapped(page) || PageNonWB(page))
+			goto out;
+
+		SetPageNonWB(page);
+	}
+	return 0;
+
+out:
+	end_pfn = pfn;
+	for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) {
+		page = pfn_to_page(pfn);
+		ClearPageNonWB(page);
+	}
+
+	return -EINVAL;
+}
+
+static int free_ram_pages_type(u64 start, u64 end)
+{
+	struct page *page;
+	u64 pfn, end_pfn;
+
+	for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
+		page = pfn_to_page(pfn);
+		if (page_mapped(page) || !PageNonWB(page))
+			goto out;
+
+		ClearPageNonWB(page);
+	}
+	return 0;
+
+out:
+	end_pfn = pfn;
+	for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) {
+		page = pfn_to_page(pfn);
+		SetPageNonWB(page);
+	}
+	return -EINVAL;
+}
+
+/*
  * req_type typically has one of the:
  * - _PAGE_CACHE_WB
  * - _PAGE_CACHE_WC
@@ -226,14 +287,15 @@ static u64 cached_start;
  * it will return a negative return value.
  */
 int reserve_memtype(u64 start, u64 end, unsigned long req_type,
-			unsigned long *new_type)
+		    unsigned long *new_type)
 {
 	struct memtype *new, *entry;
 	unsigned long actual_type;
 	struct list_head *where;
+	int is_range_ram;
 	int err = 0;
 
- 	BUG_ON(start >= end); /* end is exclusive */
+	BUG_ON(start >= end); /* end is exclusive */
 
 	if (!pat_enabled) {
 		/* This is identical to page table setting without PAT */
@@ -266,17 +328,24 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
 			actual_type = _PAGE_CACHE_WB;
 		else
 			actual_type = _PAGE_CACHE_UC_MINUS;
-	} else
+	} else {
 		actual_type = pat_x_mtrr_type(start, end,
 					      req_type & _PAGE_CACHE_MASK);
+	}
+
+	is_range_ram = pagerange_is_ram(start, end);
+	if (is_range_ram == 1)
+		return reserve_ram_pages_type(start, end, req_type, new_type);
+	else if (is_range_ram < 0)
+		return -EINVAL;
 
 	new  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
 	if (!new)
 		return -ENOMEM;
 
-	new->start = start;
-	new->end = end;
-	new->type = actual_type;
+	new->start	= start;
+	new->end	= end;
+	new->type	= actual_type;
 
 	if (new_type)
 		*new_type = actual_type;
@@ -335,6 +404,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
 		       start, end, cattr_name(new->type), cattr_name(req_type));
 		kfree(new);
 		spin_unlock(&memtype_lock);
+
 		return err;
 	}
 
@@ -358,6 +428,7 @@ int free_memtype(u64 start, u64 end)
 {
 	struct memtype *entry;
 	int err = -EINVAL;
+	int is_range_ram;
 
 	if (!pat_enabled)
 		return 0;
@@ -366,6 +437,12 @@ int free_memtype(u64 start, u64 end)
 	if (is_ISA_range(start, end - 1))
 		return 0;
 
+	is_range_ram = pagerange_is_ram(start, end);
+	if (is_range_ram == 1)
+		return free_ram_pages_type(start, end);
+	else if (is_range_ram < 0)
+		return -EINVAL;
+
 	spin_lock(&memtype_lock);
 	list_for_each_entry(entry, &memtype_list, nd) {
 		if (entry->start == start && entry->end == end) {
@@ -386,6 +463,7 @@ int free_memtype(u64 start, u64 end)
 	}
 
 	dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end);
+
 	return err;
 }
 
@@ -492,9 +570,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 
 void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
 {
+	unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
 	u64 addr = (u64)pfn << PAGE_SHIFT;
 	unsigned long flags;
-	unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
 
 	reserve_memtype(addr, addr + size, want_flags, &flags);
 	if (flags != want_flags) {
@@ -514,7 +592,7 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
 	free_memtype(addr, addr + size);
 }
 
-#if defined(CONFIG_DEBUG_FS)
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
 
 /* get Nth element of the linked list */
 static struct memtype *memtype_get_idx(loff_t pos)
@@ -537,6 +615,7 @@ static struct memtype *memtype_get_idx(loff_t pos)
 	}
 	spin_unlock(&memtype_lock);
 	kfree(print_entry);
+
 	return NULL;
 }
 
@@ -567,6 +646,7 @@ static int memtype_seq_show(struct seq_file *seq, void *v)
 	seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type),
 			print_entry->start, print_entry->end);
 	kfree(print_entry);
+
 	return 0;
 }
 
@@ -598,4 +678,4 @@ static int __init pat_memtype_list_init(void)
 
 late_initcall(pat_memtype_list_init);
 
-#endif /* CONFIG_DEBUG_FS */
+#endif /* CONFIG_DEBUG_FS && CONFIG_X86_PAT */