x86: support GB hugepages on 64-bit

Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/mm/hugetlbpage.c

@@ -134,10 +134,15 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
 	pgd = pgd_offset(mm, addr);
 	pud = pud_alloc(mm, pgd, addr);
 	if (pud) {
+		if (sz == PUD_SIZE) {
+			pte = (pte_t *)pud;
+		} else {
+			BUG_ON(sz != PMD_SIZE);
 			if (pud_none(*pud))
 				huge_pmd_share(mm, addr, pud);
 			pte = (pte_t *) pmd_alloc(mm, pud, addr);
 		}
+	}
 	BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
 
 	return pte;
@@ -152,9 +157,12 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 	pgd = pgd_offset(mm, addr);
 	if (pgd_present(*pgd)) {
 		pud = pud_offset(pgd, addr);
-		if (pud_present(*pud))
+		if (pud_present(*pud)) {
+			if (pud_large(*pud))
+				return (pte_t *)pud;
 			pmd = pmd_offset(pud, addr);
 		}
+	}
 	return (pte_t *) pmd;
 }
 
@@ -216,7 +224,7 @@ int pmd_huge(pmd_t pmd)
 
 int pud_huge(pud_t pud)
 {
-	return 0;
+	return !!(pud_val(pud) & _PAGE_PSE);
 }
 
 struct page *
@@ -252,6 +260,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
 		unsigned long addr, unsigned long len,
 		unsigned long pgoff, unsigned long flags)
 {
+	struct hstate *h = hstate_file(file);
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	unsigned long start_addr;
@@ -264,7 +273,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
 	}
 
 full_search:
-	addr = ALIGN(start_addr, HPAGE_SIZE);
+	addr = ALIGN(start_addr, huge_page_size(h));
 
 	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
 		/* At this point:  (!vma || addr < vma->vm_end). */
@@ -286,7 +295,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
 		}
 		if (addr + mm->cached_hole_size < vma->vm_start)
 		        mm->cached_hole_size = vma->vm_start - addr;
-		addr = ALIGN(vma->vm_end, HPAGE_SIZE);
+		addr = ALIGN(vma->vm_end, huge_page_size(h));
 	}
 }
 
@@ -294,6 +303,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
 		unsigned long addr0, unsigned long len,
 		unsigned long pgoff, unsigned long flags)
 {
+	struct hstate *h = hstate_file(file);
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma, *prev_vma;
 	unsigned long base = mm->mmap_base, addr = addr0;
@@ -314,7 +324,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
 		goto fail;
 
 	/* either no address requested or cant fit in requested address hole */
-	addr = (mm->free_area_cache - len) & HPAGE_MASK;
+	addr = (mm->free_area_cache - len) & huge_page_mask(h);
 	do {
 		/*
 		 * Lookup failure means no vma is above this address,
@@ -345,7 +355,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
 		        largest_hole = vma->vm_start - addr;
 
 		/* try just below the current vma->vm_start */
-		addr = (vma->vm_start - len) & HPAGE_MASK;
+		addr = (vma->vm_start - len) & huge_page_mask(h);
 	} while (len <= vma->vm_start);
 
 fail:
@@ -383,10 +393,11 @@ unsigned long
 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags)
 {
+	struct hstate *h = hstate_file(file);
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 
-	if (len & ~HPAGE_MASK)
+	if (len & ~huge_page_mask(h))
 		return -EINVAL;
 	if (len > TASK_SIZE)
 		return -ENOMEM;
@@ -398,7 +409,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 	}
 
 	if (addr) {
-		addr = ALIGN(addr, HPAGE_SIZE);
+		addr = ALIGN(addr, huge_page_size(h));
 		vma = find_vma(mm, addr);
 		if (TASK_SIZE - len >= addr &&
 		    (!vma || addr + len <= vma->vm_start))