[deliverable/linux.git] / arch / i386 / mm / hugetlbpage.c

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

#include <linux/config.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.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>

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

	pgd = pgd_offset(mm, addr);
	pud = pud_alloc(mm, pgd, addr);
	pmd = pmd_alloc(mm, pud, addr);
	return (pte_t *) pmd;
}

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);
	pud = pud_offset(pgd, addr);
	pmd = pmd_offset(pud, addr);
	return (pte_t *) pmd;
}

/*
 * This function checks for proper alignment of input addr and len parameters.
 */
int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
{
	if (len & ~HPAGE_MASK)
		return -EINVAL;
	if (addr & ~HPAGE_MASK)
		return -EINVAL;
	return 0;
}

#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

void hugetlb_clean_stale_pgtable(pte_t *pte)
{
	pmd_t *pmd = (pmd_t *) pte;
	struct page *page;

	page = pmd_page(*pmd);
	pmd_clear(pmd);
	dec_page_state(nr_page_table_pages);
	page_cache_release(page);
}

/* 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;

	start_addr = mm->free_area_cache;

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;
				goto full_search;
			}
			return -ENOMEM;
		}
		if (!vma || addr + len <= vma->vm_start) {
			mm->free_area_cache = addr + len;
			return 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;
	int first_time = 1;

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

		/* 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;
		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;
	addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
			len, pgoff, flags);

	/*
	 * Restore the topdown base:
	 */
	mm->free_area_cache = base;

	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 (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
	7	#include <linux/config.h>
	8	#include <linux/init.h>
	9	#include <linux/fs.h>
	10	#include <linux/mm.h>
	11	#include <linux/hugetlb.h>
	12	#include <linux/pagemap.h>
	13	#include <linux/smp_lock.h>
	14	#include <linux/slab.h>
	15	#include <linux/err.h>
	16	#include <linux/sysctl.h>
	17	#include <asm/mman.h>
	18	#include <asm/tlb.h>
	19	#include <asm/tlbflush.h>
	20
63551ae0	21	pte_t huge_pte_alloc(struct mm_struct mm, unsigned long addr)
1da177e4 LT	22	{
	23	pgd_t *pgd;
	24	pud_t *pud;
	25	pmd_t *pmd = NULL;
	26
	27	pgd = pgd_offset(mm, addr);
	28	pud = pud_alloc(mm, pgd, addr);
	29	pmd = pmd_alloc(mm, pud, addr);
	30	return (pte_t *) pmd;
	31	}
	32
63551ae0	33	pte_t huge_pte_offset(struct mm_struct mm, unsigned long addr)
1da177e4 LT	34	{
	35	pgd_t *pgd;
	36	pud_t *pud;
	37	pmd_t *pmd = NULL;
	38
	39	pgd = pgd_offset(mm, addr);
	40	pud = pud_offset(pgd, addr);
	41	pmd = pmd_offset(pud, addr);
	42	return (pte_t *) pmd;
	43	}
	44
1da177e4 LT	45	/*
	46	* This function checks for proper alignment of input addr and len parameters.
	47	*/
	48	int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
	49	{
	50	if (len & ~HPAGE_MASK)
	51	return -EINVAL;
	52	if (addr & ~HPAGE_MASK)
	53	return -EINVAL;
	54	return 0;
	55	}
	56
1da177e4 LT	57	#if 0 /* This is just for testing */
	58	struct page *
	59	follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
	60	{
	61	unsigned long start = address;
	62	int length = 1;
	63	int nr;
	64	struct page *page;
	65	struct vm_area_struct *vma;
	66
	67	vma = find_vma(mm, addr);
	68	if (!vma \|\| !is_vm_hugetlb_page(vma))
	69	return ERR_PTR(-EINVAL);
	70
	71	pte = huge_pte_offset(mm, address);
	72
	73	/* hugetlb should be locked, and hence, prefaulted */
	74	WARN_ON(!pte \|\| pte_none(*pte));
	75
	76	page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
	77
	78	WARN_ON(!PageCompound(page));
	79
	80	return page;
	81	}
	82
	83	int pmd_huge(pmd_t pmd)
	84	{
	85	return 0;
	86	}
	87
	88	struct page *
	89	follow_huge_pmd(struct mm_struct *mm, unsigned long address,
	90	pmd_t *pmd, int write)
	91	{
	92	return NULL;
	93	}
	94
	95	#else
	96
	97	struct page *
	98	follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
	99	{
	100	return ERR_PTR(-EINVAL);
	101	}
	102
	103	int pmd_huge(pmd_t pmd)
	104	{
	105	return !!(pmd_val(pmd) & _PAGE_PSE);
	106	}
	107
	108	struct page *
	109	follow_huge_pmd(struct mm_struct *mm, unsigned long address,
	110	pmd_t *pmd, int write)
	111	{
	112	struct page *page;
	113
	114	page = pte_page((pte_t )pmd);
	115	if (page)
	116	page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
	117	return page;
	118	}
	119	#endif
	120
63551ae0	121	void hugetlb_clean_stale_pgtable(pte_t *pte)
1da177e4	122	{
63551ae0	123	pmd_t pmd = (pmd_t ) pte;
1da177e4 LT	124	struct page *page;
1da177e4 LT	125
63551ae0 DG	126	page = pmd_page(*pmd);
	127	pmd_clear(pmd);
	128	dec_page_state(nr_page_table_pages);
	129	page_cache_release(page);
1da177e4 LT	130	}
	131
	132	/* x86_64 also uses this file */
	133
	134	#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
	135	static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
	136	unsigned long addr, unsigned long len,
	137	unsigned long pgoff, unsigned long flags)
	138	{
	139	struct mm_struct *mm = current->mm;
	140	struct vm_area_struct *vma;
	141	unsigned long start_addr;
	142
	143	start_addr = mm->free_area_cache;
	144
	145	full_search:
	146	addr = ALIGN(start_addr, HPAGE_SIZE);
	147
	148	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
	149	/* At this point: (!vma \|\| addr < vma->vm_end). */
	150	if (TASK_SIZE - len < addr) {
	151	/*
	152	* Start a new search - just in case we missed
	153	* some holes.
	154	*/
	155	if (start_addr != TASK_UNMAPPED_BASE) {
	156	start_addr = TASK_UNMAPPED_BASE;
	157	goto full_search;
	158	}
	159	return -ENOMEM;
	160	}
	161	if (!vma \|\| addr + len <= vma->vm_start) {
	162	mm->free_area_cache = addr + len;
	163	return addr;
	164	}
	165	addr = ALIGN(vma->vm_end, HPAGE_SIZE);
	166	}
	167	}
	168
	169	static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
	170	unsigned long addr0, unsigned long len,
	171	unsigned long pgoff, unsigned long flags)
	172	{
	173	struct mm_struct *mm = current->mm;
	174	struct vm_area_struct vma, prev_vma;
	175	unsigned long base = mm->mmap_base, addr = addr0;
	176	int first_time = 1;
	177
	178	/* don't allow allocations above current base */
	179	if (mm->free_area_cache > base)
	180	mm->free_area_cache = base;
	181
	182	try_again:
	183	/* make sure it can fit in the remaining address space */
	184	if (mm->free_area_cache < len)
	185	goto fail;
	186
	187	/* either no address requested or cant fit in requested address hole */
	188	addr = (mm->free_area_cache - len) & HPAGE_MASK;
	189	do {
	190	/*
	191	* Lookup failure means no vma is above this address,
	192	* i.e. return with success:
	193	*/
194	if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
195	return addr;
196
197	/*
198	* new region fits between prev_vma->vm_end and
199	* vma->vm_start, use it:
200	*/
201	if (addr + len <= vma->vm_start &&
202	(!prev_vma \|\| (addr >= prev_vma->vm_end)))
203	/* remember the address as a hint for next time */
204	return (mm->free_area_cache = addr);
205	else
206	/* pull free_area_cache down to the first hole */
207	if (mm->free_area_cache == vma->vm_end)
208	mm->free_area_cache = vma->vm_start;
209
210	/* try just below the current vma->vm_start */
211	addr = (vma->vm_start - len) & HPAGE_MASK;
212	} while (len <= vma->vm_start);
213
214	fail:
215	/*
216	* if hint left us with no space for the requested
217	* mapping then try again:
218	*/
219	if (first_time) {
220	mm->free_area_cache = base;
221	first_time = 0;
222	goto try_again;
223	}
224	/*
225	* A failed mmap() very likely causes application failure,
226	* so fall back to the bottom-up function here. This scenario
227	* can happen with large stack limits and large mmap()
228	* allocations.
229	*/
230	mm->free_area_cache = TASK_UNMAPPED_BASE;
231	addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
232	len, pgoff, flags);
233
234	/*
235	* Restore the topdown base:
236	*/
237	mm->free_area_cache = base;
238
239	return addr;
240	}
241
242	unsigned long
243	hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
244	unsigned long len, unsigned long pgoff, unsigned long flags)
245	{
246	struct mm_struct *mm = current->mm;
247	struct vm_area_struct *vma;
248
249	if (len & ~HPAGE_MASK)
250	return -EINVAL;
251	if (len > TASK_SIZE)
252	return -ENOMEM;
253
254	if (addr) {
255	addr = ALIGN(addr, HPAGE_SIZE);
256	vma = find_vma(mm, addr);
257	if (TASK_SIZE - len >= addr &&
258	(!vma \|\| addr + len <= vma->vm_start))
259	return addr;
260	}
261	if (mm->get_unmapped_area == arch_get_unmapped_area)
262	return hugetlb_get_unmapped_area_bottomup(file, addr, len,
263	pgoff, flags);
264	else
265	return hugetlb_get_unmapped_area_topdown(file, addr, len,
266	pgoff, flags);
267	}
268
269	#endif /HAVE_ARCH_HUGETLB_UNMAPPED_AREA/
270