[deliverable/linux.git] / arch / x86 / mm / hugetlbpage.c

/*
 * IA-32 Huge TLB Page Support for Kernel.
 *
 * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
 */

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/sysctl.h>
#include <asm/mman.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>

static unsigned long page_table_shareable(struct vm_area_struct *svma,
				struct vm_area_struct *vma,
				unsigned long addr, pgoff_t idx)
{
	unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
				svma->vm_start;
	unsigned long sbase = saddr & PUD_MASK;
	unsigned long s_end = sbase + PUD_SIZE;

	/*
	 * match the virtual addresses, permission and the alignment of the
	 * page table page.
	 */
	if (pmd_index(addr) != pmd_index(saddr) ||
	    vma->vm_flags != svma->vm_flags ||
	    sbase < svma->vm_start || svma->vm_end < s_end)
		return 0;

	return saddr;
}

static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
{
	unsigned long base = addr & PUD_MASK;
	unsigned long end = base + PUD_SIZE;

	/*
	 * check on proper vm_flags and page table alignment
	 */
	if (vma->vm_flags & VM_MAYSHARE &&
	    vma->vm_start <= base && end <= vma->vm_end)
		return 1;
	return 0;
}

/*
 * search for a shareable pmd page for hugetlb.
 */
static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
	struct vm_area_struct *vma = find_vma(mm, addr);
	struct address_space *mapping = vma->vm_file->f_mapping;
	pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
			vma->vm_pgoff;
	struct prio_tree_iter iter;
	struct vm_area_struct *svma;
	unsigned long saddr;
	pte_t *spte = NULL;

	if (!vma_shareable(vma, addr))
		return;

	spin_lock(&mapping->i_mmap_lock);
	vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
		if (svma == vma)
			continue;

		saddr = page_table_shareable(svma, vma, addr, idx);
		if (saddr) {
			spte = huge_pte_offset(svma->vm_mm, saddr);
			if (spte) {
				get_page(virt_to_page(spte));
				break;
			}
		}
	}

	if (!spte)
		goto out;

	spin_lock(&mm->page_table_lock);
	if (pud_none(*pud))
		pud_populate(mm, pud, (unsigned long) spte & PAGE_MASK);
	else
		put_page(virt_to_page(spte));
	spin_unlock(&mm->page_table_lock);
out:
	spin_unlock(&mapping->i_mmap_lock);
}

/*
 * unmap huge page backed by shared pte.
 *
 * Hugetlb pte page is ref counted at the time of mapping.  If pte is shared
 * indicated by page_count > 1, unmap is achieved by clearing pud and
 * decrementing the ref count. If count == 1, the pte page is not shared.
 *
 * called with vma->vm_mm->page_table_lock held.
 *
 * returns: 1 successfully unmapped a shared pte page
 *	    0 the underlying pte page is not shared, or it is the last user
 */
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
	pgd_t *pgd = pgd_offset(mm, *addr);
	pud_t *pud = pud_offset(pgd, *addr);

	BUG_ON(page_count(virt_to_page(ptep)) == 0);
	if (page_count(virt_to_page(ptep)) == 1)
		return 0;

	pud_clear(pud);
	put_page(virt_to_page(ptep));
	*addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
	return 1;
}

pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pud_t *pud;
	pte_t *pte = NULL;

	pgd = pgd_offset(mm, addr);
	pud = pud_alloc(mm, pgd, addr);
	if (pud) {
		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;
}

pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd = NULL;

	pgd = pgd_offset(mm, addr);
	if (pgd_present(*pgd)) {
		pud = pud_offset(pgd, addr);
		if (pud_present(*pud))
			pmd = pmd_offset(pud, addr);
	}
	return (pte_t *) pmd;
}

#if 0	/* This is just for testing */
struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
{
	unsigned long start = address;
	int length = 1;
	int nr;
	struct page *page;
	struct vm_area_struct *vma;

	vma = find_vma(mm, addr);
	if (!vma || !is_vm_hugetlb_page(vma))
		return ERR_PTR(-EINVAL);

	pte = huge_pte_offset(mm, address);

	/* hugetlb should be locked, and hence, prefaulted */
	WARN_ON(!pte || pte_none(*pte));

	page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];

	WARN_ON(!PageCompound(page));

	return page;
}

int pmd_huge(pmd_t pmd)
{
	return 0;
}

struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
		pmd_t *pmd, int write)
{
	return NULL;
}

#else

struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
{
	return ERR_PTR(-EINVAL);
}

int pmd_huge(pmd_t pmd)
{
	return !!(pmd_val(pmd) & _PAGE_PSE);
}

struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
		pmd_t *pmd, int write)
{
	struct page *page;

	page = pte_page(*(pte_t *)pmd);
	if (page)
		page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
	return page;
}
#endif

/* x86_64 also uses this file */

#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
		unsigned long addr, unsigned long len,
		unsigned long pgoff, unsigned long flags)
{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	unsigned long start_addr;

	if (len > mm->cached_hole_size) {
	        start_addr = mm->free_area_cache;
	} else {
	        start_addr = TASK_UNMAPPED_BASE;
	        mm->cached_hole_size = 0;
	}

full_search:
	addr = ALIGN(start_addr, HPAGE_SIZE);

	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
		/* At this point:  (!vma || addr < vma->vm_end). */
		if (TASK_SIZE - len < addr) {
			/*
			 * Start a new search - just in case we missed
			 * some holes.
			 */
			if (start_addr != TASK_UNMAPPED_BASE) {
				start_addr = TASK_UNMAPPED_BASE;
				mm->cached_hole_size = 0;
				goto full_search;
			}
			return -ENOMEM;
		}
		if (!vma || addr + len <= vma->vm_start) {
			mm->free_area_cache = addr + len;
			return addr;
		}
		if (addr + mm->cached_hole_size < vma->vm_start)
		        mm->cached_hole_size = vma->vm_start - addr;
		addr = ALIGN(vma->vm_end, HPAGE_SIZE);
	}
}

static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
		unsigned long addr0, unsigned long len,
		unsigned long pgoff, unsigned long flags)
{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma, *prev_vma;
	unsigned long base = mm->mmap_base, addr = addr0;
	unsigned long largest_hole = mm->cached_hole_size;
	int first_time = 1;

	/* don't allow allocations above current base */
	if (mm->free_area_cache > base)
		mm->free_area_cache = base;

	if (len <= largest_hole) {
	        largest_hole = 0;
		mm->free_area_cache  = base;
	}
try_again:
	/* make sure it can fit in the remaining address space */
	if (mm->free_area_cache < len)
		goto fail;

	/* either no address requested or cant fit in requested address hole */
	addr = (mm->free_area_cache - len) & HPAGE_MASK;
	do {
		/*
		 * Lookup failure means no vma is above this address,
		 * i.e. return with success:
		 */
		if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
			return addr;

		/*
		 * new region fits between prev_vma->vm_end and
		 * vma->vm_start, use it:
		 */
		if (addr + len <= vma->vm_start &&
		            (!prev_vma || (addr >= prev_vma->vm_end))) {
			/* remember the address as a hint for next time */
		        mm->cached_hole_size = largest_hole;
		        return (mm->free_area_cache = addr);
		} else {
			/* pull free_area_cache down to the first hole */
		        if (mm->free_area_cache == vma->vm_end) {
				mm->free_area_cache = vma->vm_start;
				mm->cached_hole_size = largest_hole;
			}
		}

		/* remember the largest hole we saw so far */
		if (addr + largest_hole < vma->vm_start)
		        largest_hole = vma->vm_start - addr;

		/* try just below the current vma->vm_start */
		addr = (vma->vm_start - len) & HPAGE_MASK;
	} while (len <= vma->vm_start);

fail:
	/*
	 * if hint left us with no space for the requested
	 * mapping then try again:
	 */
	if (first_time) {
		mm->free_area_cache = base;
		largest_hole = 0;
		first_time = 0;
		goto try_again;
	}
	/*
	 * A failed mmap() very likely causes application failure,
	 * so fall back to the bottom-up function here. This scenario
	 * can happen with large stack limits and large mmap()
	 * allocations.
	 */
	mm->free_area_cache = TASK_UNMAPPED_BASE;
	mm->cached_hole_size = ~0UL;
	addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
			len, pgoff, flags);

	/*
	 * Restore the topdown base:
	 */
	mm->free_area_cache = base;
	mm->cached_hole_size = ~0UL;

	return addr;
}

unsigned long
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags)
{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;

	if (len & ~HPAGE_MASK)
		return -EINVAL;
	if (len > TASK_SIZE)
		return -ENOMEM;

	if (flags & MAP_FIXED) {
		if (prepare_hugepage_range(addr, len))
			return -EINVAL;
		return addr;
	}

	if (addr) {
		addr = ALIGN(addr, HPAGE_SIZE);
		vma = find_vma(mm, addr);
		if (TASK_SIZE - len >= addr &&
		    (!vma || addr + len <= vma->vm_start))
			return addr;
	}
	if (mm->get_unmapped_area == arch_get_unmapped_area)
		return hugetlb_get_unmapped_area_bottomup(file, addr, len,
				pgoff, flags);
	else
		return hugetlb_get_unmapped_area_topdown(file, addr, len,
				pgoff, flags);
}

#endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
Commit	Line	Data
1da177e4 LT	1	/*
	2	* IA-32 Huge TLB Page Support for Kernel.
	3	*
	4	* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
	5	*/
	6
1da177e4 LT	7	#include <linux/init.h>
	8	#include <linux/fs.h>
	9	#include <linux/mm.h>
	10	#include <linux/hugetlb.h>
	11	#include <linux/pagemap.h>
1da177e4 LT	12	#include <linux/slab.h>
	13	#include <linux/err.h>
	14	#include <linux/sysctl.h>
	15	#include <asm/mman.h>
	16	#include <asm/tlb.h>
	17	#include <asm/tlbflush.h>
	18
39dde65c CK	19	static unsigned long page_table_shareable(struct vm_area_struct *svma,
	20	struct vm_area_struct *vma,
	21	unsigned long addr, pgoff_t idx)
	22	{
	23	unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
	24	svma->vm_start;
	25	unsigned long sbase = saddr & PUD_MASK;
	26	unsigned long s_end = sbase + PUD_SIZE;
	27
	28	/*
	29	* match the virtual addresses, permission and the alignment of the
	30	* page table page.
	31	*/
	32	if (pmd_index(addr) != pmd_index(saddr) \|\|
	33	vma->vm_flags != svma->vm_flags \|\|
	34	sbase < svma->vm_start \|\| svma->vm_end < s_end)
	35	return 0;
	36
	37	return saddr;
	38	}
	39
	40	static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
	41	{
	42	unsigned long base = addr & PUD_MASK;
	43	unsigned long end = base + PUD_SIZE;
	44
	45	/*
	46	* check on proper vm_flags and page table alignment
	47	*/
	48	if (vma->vm_flags & VM_MAYSHARE &&
	49	vma->vm_start <= base && end <= vma->vm_end)
	50	return 1;
	51	return 0;
	52	}
	53
	54	/*
	55	* search for a shareable pmd page for hugetlb.
	56	*/
	57	static void huge_pmd_share(struct mm_struct mm, unsigned long addr, pud_t pud)
	58	{
	59	struct vm_area_struct *vma = find_vma(mm, addr);
	60	struct address_space *mapping = vma->vm_file->f_mapping;
	61	pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
	62	vma->vm_pgoff;
	63	struct prio_tree_iter iter;
	64	struct vm_area_struct *svma;
	65	unsigned long saddr;
	66	pte_t *spte = NULL;
	67
	68	if (!vma_shareable(vma, addr))
	69	return;
	70
	71	spin_lock(&mapping->i_mmap_lock);
	72	vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
	73	if (svma == vma)
	74	continue;
	75
	76	saddr = page_table_shareable(svma, vma, addr, idx);
	77	if (saddr) {
	78	spte = huge_pte_offset(svma->vm_mm, saddr);
	79	if (spte) {
	80	get_page(virt_to_page(spte));
	81	break;
	82	}
83	}
84	}
85
86	if (!spte)
87	goto out;
88
89	spin_lock(&mm->page_table_lock);
90	if (pud_none(*pud))
91	pud_populate(mm, pud, (unsigned long) spte & PAGE_MASK);
92	else
93	put_page(virt_to_page(spte));
94	spin_unlock(&mm->page_table_lock);
95	out:
96	spin_unlock(&mapping->i_mmap_lock);
97	}
98
99	/*
100	* unmap huge page backed by shared pte.
101	*
102	* Hugetlb pte page is ref counted at the time of mapping. If pte is shared
103	* indicated by page_count > 1, unmap is achieved by clearing pud and
104	* decrementing the ref count. If count == 1, the pte page is not shared.
105	*
106	* called with vma->vm_mm->page_table_lock held.
107	*
108	* returns: 1 successfully unmapped a shared pte page
109	* 0 the underlying pte page is not shared, or it is the last user
110	*/
111	int huge_pmd_unshare(struct mm_struct mm, unsigned long addr, pte_t *ptep)
112	{
113	pgd_t pgd = pgd_offset(mm, addr);
114	pud_t pud = pud_offset(pgd, addr);
115
116	BUG_ON(page_count(virt_to_page(ptep)) == 0);
117	if (page_count(virt_to_page(ptep)) == 1)
118	return 0;
119
120	pud_clear(pud);
121	put_page(virt_to_page(ptep));
122	addr = ALIGN(addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
123	return 1;
124	}
125
63551ae0	126	pte_t huge_pte_alloc(struct mm_struct mm, unsigned long addr)
1da177e4 LT	127	{
	128	pgd_t *pgd;
	129	pud_t *pud;
7bf07f3d	130	pte_t *pte = NULL;
1da177e4 LT	131
	132	pgd = pgd_offset(mm, addr);
	133	pud = pud_alloc(mm, pgd, addr);
39dde65c CK	134	if (pud) {
	135	if (pud_none(*pud))
	136	huge_pmd_share(mm, addr, pud);
0e5c9f39	137	pte = (pte_t *) pmd_alloc(mm, pud, addr);
39dde65c	138	}
0e5c9f39	139	BUG_ON(pte && !pte_none(pte) && !pte_huge(pte));
7bf07f3d	140
7bf07f3d	141	return pte;
1da177e4 LT	142	}
1da177e4 LT	143
63551ae0	144	pte_t huge_pte_offset(struct mm_struct mm, unsigned long addr)
1da177e4 LT	145	{
	146	pgd_t *pgd;
	147	pud_t *pud;
	148	pmd_t *pmd = NULL;
	149
	150	pgd = pgd_offset(mm, addr);
02b0ccef AL	151	if (pgd_present(*pgd)) {
	152	pud = pud_offset(pgd, addr);
	153	if (pud_present(*pud))
	154	pmd = pmd_offset(pud, addr);
	155	}
1da177e4 LT	156	return (pte_t *) pmd;
	157	}
	158
1da177e4 LT	159	#if 0 /* This is just for testing */
	160	struct page *
	161	follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
	162	{
	163	unsigned long start = address;
	164	int length = 1;
	165	int nr;
	166	struct page *page;
	167	struct vm_area_struct *vma;
	168
	169	vma = find_vma(mm, addr);
	170	if (!vma \|\| !is_vm_hugetlb_page(vma))
	171	return ERR_PTR(-EINVAL);
	172
	173	pte = huge_pte_offset(mm, address);
	174
	175	/* hugetlb should be locked, and hence, prefaulted */
	176	WARN_ON(!pte \|\| pte_none(*pte));
	177
	178	page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
	179
	180	WARN_ON(!PageCompound(page));
	181
	182	return page;
	183	}
	184
	185	int pmd_huge(pmd_t pmd)
	186	{
	187	return 0;
	188	}
	189
	190	struct page *
	191	follow_huge_pmd(struct mm_struct *mm, unsigned long address,
	192	pmd_t *pmd, int write)
	193	{
	194	return NULL;
	195	}
	196
	197	#else
	198
	199	struct page *
	200	follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
	201	{
	202	return ERR_PTR(-EINVAL);
	203	}
	204
	205	int pmd_huge(pmd_t pmd)
	206	{
	207	return !!(pmd_val(pmd) & _PAGE_PSE);
	208	}
	209
	210	struct page *
	211	follow_huge_pmd(struct mm_struct *mm, unsigned long address,
	212	pmd_t *pmd, int write)
	213	{
	214	struct page *page;
	215
	216	page = pte_page((pte_t )pmd);
	217	if (page)
	218	page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
	219	return page;
	220	}
	221	#endif
	222
1da177e4 LT	223	/* x86_64 also uses this file */
	224
	225	#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
	226	static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
	227	unsigned long addr, unsigned long len,
	228	unsigned long pgoff, unsigned long flags)
	229	{
	230	struct mm_struct *mm = current->mm;
	231	struct vm_area_struct *vma;
	232	unsigned long start_addr;
	233
1363c3cd WW	234	if (len > mm->cached_hole_size) {
	235	start_addr = mm->free_area_cache;
	236	} else {
	237	start_addr = TASK_UNMAPPED_BASE;
	238	mm->cached_hole_size = 0;
	239	}
1da177e4 LT	240
	241	full_search:
	242	addr = ALIGN(start_addr, HPAGE_SIZE);
	243
	244	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
	245	/* At this point: (!vma \|\| addr < vma->vm_end). */
	246	if (TASK_SIZE - len < addr) {
	247	/*
	248	* Start a new search - just in case we missed
	249	* some holes.
	250	*/
	251	if (start_addr != TASK_UNMAPPED_BASE) {
	252	start_addr = TASK_UNMAPPED_BASE;
1363c3cd	253	mm->cached_hole_size = 0;
1da177e4 LT	254	goto full_search;
	255	}
	256	return -ENOMEM;
	257	}
	258	if (!vma \|\| addr + len <= vma->vm_start) {
	259	mm->free_area_cache = addr + len;
	260	return addr;
	261	}
1363c3cd WW	262	if (addr + mm->cached_hole_size < vma->vm_start)
1363c3cd WW	263	mm->cached_hole_size = vma->vm_start - addr;
1da177e4 LT	264	addr = ALIGN(vma->vm_end, HPAGE_SIZE);
	265	}
	266	}
	267
	268	static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
	269	unsigned long addr0, unsigned long len,
	270	unsigned long pgoff, unsigned long flags)
	271	{
	272	struct mm_struct *mm = current->mm;
	273	struct vm_area_struct vma, prev_vma;
	274	unsigned long base = mm->mmap_base, addr = addr0;
1363c3cd	275	unsigned long largest_hole = mm->cached_hole_size;
1da177e4 LT	276	int first_time = 1;
	277
	278	/* don't allow allocations above current base */
	279	if (mm->free_area_cache > base)
	280	mm->free_area_cache = base;
	281
1363c3cd WW	282	if (len <= largest_hole) {
	283	largest_hole = 0;
	284	mm->free_area_cache = base;
	285	}
1da177e4 LT	286	try_again:
	287	/* make sure it can fit in the remaining address space */
	288	if (mm->free_area_cache < len)
	289	goto fail;
	290
	291	/* either no address requested or cant fit in requested address hole */
	292	addr = (mm->free_area_cache - len) & HPAGE_MASK;
	293	do {
	294	/*
	295	* Lookup failure means no vma is above this address,
	296	* i.e. return with success:
	297	*/
	298	if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
	299	return addr;
	300
	301	/*
	302	* new region fits between prev_vma->vm_end and
	303	* vma->vm_start, use it:
	304	*/
	305	if (addr + len <= vma->vm_start &&
1363c3cd	306	(!prev_vma \|\| (addr >= prev_vma->vm_end))) {
1da177e4	307	/* remember the address as a hint for next time */
1363c3cd WW	308	mm->cached_hole_size = largest_hole;
	309	return (mm->free_area_cache = addr);
	310	} else {
1da177e4	311	/* pull free_area_cache down to the first hole */
1363c3cd	312	if (mm->free_area_cache == vma->vm_end) {
1da177e4	313	mm->free_area_cache = vma->vm_start;
1363c3cd WW	314	mm->cached_hole_size = largest_hole;
	315	}
	316	}
	317
	318	/* remember the largest hole we saw so far */
	319	if (addr + largest_hole < vma->vm_start)
	320	largest_hole = vma->vm_start - addr;
1da177e4 LT	321
	322	/* try just below the current vma->vm_start */
	323	addr = (vma->vm_start - len) & HPAGE_MASK;
	324	} while (len <= vma->vm_start);
	325
	326	fail:
	327	/*
	328	* if hint left us with no space for the requested
	329	* mapping then try again:
	330	*/
	331	if (first_time) {
	332	mm->free_area_cache = base;
1363c3cd	333	largest_hole = 0;
1da177e4 LT	334	first_time = 0;
	335	goto try_again;
	336	}
	337	/*
	338	* A failed mmap() very likely causes application failure,
	339	* so fall back to the bottom-up function here. This scenario
	340	* can happen with large stack limits and large mmap()
	341	* allocations.
	342	*/
	343	mm->free_area_cache = TASK_UNMAPPED_BASE;
1363c3cd	344	mm->cached_hole_size = ~0UL;
1da177e4 LT	345	addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
	346	len, pgoff, flags);
	347
	348	/*
	349	* Restore the topdown base:
	350	*/
	351	mm->free_area_cache = base;
1363c3cd	352	mm->cached_hole_size = ~0UL;
1da177e4 LT	353
	354	return addr;
	355	}
	356
	357	unsigned long
	358	hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
	359	unsigned long len, unsigned long pgoff, unsigned long flags)
	360	{
	361	struct mm_struct *mm = current->mm;
	362	struct vm_area_struct *vma;
	363
	364	if (len & ~HPAGE_MASK)
	365	return -EINVAL;
	366	if (len > TASK_SIZE)
	367	return -ENOMEM;
	368
5a8130f2	369	if (flags & MAP_FIXED) {
dec4ad86	370	if (prepare_hugepage_range(addr, len))
5a8130f2 BH	371	return -EINVAL;
	372	return addr;
	373	}
	374
1da177e4 LT	375	if (addr) {
	376	addr = ALIGN(addr, HPAGE_SIZE);
	377	vma = find_vma(mm, addr);
	378	if (TASK_SIZE - len >= addr &&
	379	(!vma \|\| addr + len <= vma->vm_start))
	380	return addr;
	381	}
	382	if (mm->get_unmapped_area == arch_get_unmapped_area)
	383	return hugetlb_get_unmapped_area_bottomup(file, addr, len,
	384	pgoff, flags);
	385	else
	386	return hugetlb_get_unmapped_area_topdown(file, addr, len,
	387	pgoff, flags);
	388	}
	389
	390	#endif /HAVE_ARCH_HUGETLB_UNMAPPED_AREA/
	391