[deliverable/linux.git] / arch / ia64 / mm / hugetlbpage.c

/*
 * IA-64 Huge TLB Page Support for Kernel.
 *
 * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
 * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
 *
 * Sep, 2003: add numa support
 * Feb, 2004: dynamic hugetlb page size via boot parameter
 */

#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/sysctl.h>
#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>

unsigned int hpage_shift=HPAGE_SHIFT_DEFAULT;

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

	pgd = pgd_offset(mm, taddr);
	pud = pud_alloc(mm, pgd, taddr);
	if (pud) {
		pmd = pmd_alloc(mm, pud, taddr);
		if (pmd)
			pte = pte_alloc_map(mm, pmd, taddr);
	}
	return pte;
}

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

	pgd = pgd_offset(mm, taddr);
	if (pgd_present(*pgd)) {
		pud = pud_offset(pgd, taddr);
		if (pud_present(*pud)) {
			pmd = pmd_offset(pud, taddr);
			if (pmd_present(*pmd))
				pte = pte_offset_map(pmd, taddr);
		}
	}

	return pte;
}

#define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }

static void
set_huge_pte (struct mm_struct *mm, struct vm_area_struct *vma,
	      struct page *page, pte_t * page_table, int write_access)
{
	pte_t entry;

	add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
	if (write_access) {
		entry =
		    pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
	} else
		entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
	entry = pte_mkyoung(entry);
	mk_pte_huge(entry);
	set_pte(page_table, entry);
	return;
}
/*
 * 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;
	if (REGION_NUMBER(addr) != REGION_HPAGE)
		return -EINVAL;

	return 0;
}

int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
			struct vm_area_struct *vma)
{
	pte_t *src_pte, *dst_pte, entry;
	struct page *ptepage;
	unsigned long addr = vma->vm_start;
	unsigned long end = vma->vm_end;

	while (addr < end) {
		dst_pte = huge_pte_alloc(dst, addr);
		if (!dst_pte)
			goto nomem;
		src_pte = huge_pte_offset(src, addr);
		entry = *src_pte;
		ptepage = pte_page(entry);
		get_page(ptepage);
		set_pte(dst_pte, entry);
		add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
		addr += HPAGE_SIZE;
	}
	return 0;
nomem:
	return -ENOMEM;
}

int
follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
		    struct page **pages, struct vm_area_struct **vmas,
		    unsigned long *st, int *length, int i)
{
	pte_t *ptep, pte;
	unsigned long start = *st;
	unsigned long pstart;
	int len = *length;
	struct page *page;

	do {
		pstart = start & HPAGE_MASK;
		ptep = huge_pte_offset(mm, start);
		pte = *ptep;

back1:
		page = pte_page(pte);
		if (pages) {
			page += ((start & ~HPAGE_MASK) >> PAGE_SHIFT);
			get_page(page);
			pages[i] = page;
		}
		if (vmas)
			vmas[i] = vma;
		i++;
		len--;
		start += PAGE_SIZE;
		if (((start & HPAGE_MASK) == pstart) && len &&
				(start < vma->vm_end))
			goto back1;
	} while (len && start < vma->vm_end);
	*length = len;
	*st = start;
	return i;
}

struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
{
	struct page *page;
	pte_t *ptep;

	if (REGION_NUMBER(addr) != REGION_HPAGE)
		return ERR_PTR(-EINVAL);

	ptep = huge_pte_offset(mm, addr);
	if (!ptep || pte_none(*ptep))
		return NULL;
	page = pte_page(*ptep);
	page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
	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;
}

void hugetlb_free_pgd_range(struct mmu_gather **tlb,
			unsigned long addr, unsigned long end,
			unsigned long floor, unsigned long ceiling)
{
	/*
	 * This is called only when is_hugepage_only_range(addr,),
	 * and it follows that is_hugepage_only_range(end,) also.
	 *
	 * The offset of these addresses from the base of the hugetlb
	 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
	 * the standard free_pgd_range will free the right page tables.
	 *
	 * If floor and ceiling are also in the hugetlb region, they
	 * must likewise be scaled down; but if outside, left unchanged.
	 */

	addr = htlbpage_to_page(addr);
	end  = htlbpage_to_page(end);
	if (is_hugepage_only_range(tlb->mm, floor, HPAGE_SIZE))
		floor = htlbpage_to_page(floor);
	if (is_hugepage_only_range(tlb->mm, ceiling, HPAGE_SIZE))
		ceiling = htlbpage_to_page(ceiling);

	free_pgd_range(tlb, addr, end, floor, ceiling);
}

void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;
	unsigned long address;
	pte_t *pte;
	struct page *page;

	BUG_ON(start & (HPAGE_SIZE - 1));
	BUG_ON(end & (HPAGE_SIZE - 1));

	for (address = start; address < end; address += HPAGE_SIZE) {
		pte = huge_pte_offset(mm, address);
		if (pte_none(*pte))
			continue;
		page = pte_page(*pte);
		put_page(page);
		pte_clear(mm, address, pte);
	}
	add_mm_counter(mm, rss, - ((end - start) >> PAGE_SHIFT));
	flush_tlb_range(vma, start, end);
}

int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
{
	struct mm_struct *mm = current->mm;
	unsigned long addr;
	int ret = 0;

	BUG_ON(vma->vm_start & ~HPAGE_MASK);
	BUG_ON(vma->vm_end & ~HPAGE_MASK);

	spin_lock(&mm->page_table_lock);
	for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
		unsigned long idx;
		pte_t *pte = huge_pte_alloc(mm, addr);
		struct page *page;

		if (!pte) {
			ret = -ENOMEM;
			goto out;
		}
		if (!pte_none(*pte))
			continue;

		idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
			+ (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
		page = find_get_page(mapping, idx);
		if (!page) {
			/* charge the fs quota first */
			if (hugetlb_get_quota(mapping)) {
				ret = -ENOMEM;
				goto out;
			}
			page = alloc_huge_page();
			if (!page) {
				hugetlb_put_quota(mapping);
				ret = -ENOMEM;
				goto out;
			}
			ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
			if (! ret) {
				unlock_page(page);
			} else {
				hugetlb_put_quota(mapping);
				page_cache_release(page);
				goto out;
			}
		}
		set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE);
	}
out:
	spin_unlock(&mm->page_table_lock);
	return ret;
}

unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
		unsigned long pgoff, unsigned long flags)
{
	struct vm_area_struct *vmm;

	if (len > RGN_MAP_LIMIT)
		return -ENOMEM;
	if (len & ~HPAGE_MASK)
		return -EINVAL;
	/* This code assumes that REGION_HPAGE != 0. */
	if ((REGION_NUMBER(addr) != REGION_HPAGE) || (addr & (HPAGE_SIZE - 1)))
		addr = HPAGE_REGION_BASE;
	else
		addr = ALIGN(addr, HPAGE_SIZE);
	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
		/* At this point:  (!vmm || addr < vmm->vm_end). */
		if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
			return -ENOMEM;
		if (!vmm || (addr + len) <= vmm->vm_start)
			return addr;
		addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
	}
}

static int __init hugetlb_setup_sz(char *str)
{
	u64 tr_pages;
	unsigned long long size;

	if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
		/*
		 * shouldn't happen, but just in case.
		 */
		tr_pages = 0x15557000UL;

	size = memparse(str, &str);
	if (*str || (size & (size-1)) || !(tr_pages & size) ||
		size <= PAGE_SIZE ||
		size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
		printk(KERN_WARNING "Invalid huge page size specified\n");
		return 1;
	}

	hpage_shift = __ffs(size);
	/*
	 * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
	 * override here with new page shift.
	 */
	ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
	return 1;
}
__setup("hugepagesz=", hugetlb_setup_sz);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* IA-64 Huge TLB Page Support for Kernel.
	3	*
	4	* Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
	5	* Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
	6	*
	7	* Sep, 2003: add numa support
	8	* Feb, 2004: dynamic hugetlb page size via boot parameter
	9	*/
	10
	11	#include <linux/config.h>
	12	#include <linux/init.h>
	13	#include <linux/fs.h>
	14	#include <linux/mm.h>
	15	#include <linux/hugetlb.h>
	16	#include <linux/pagemap.h>
	17	#include <linux/smp_lock.h>
	18	#include <linux/slab.h>
	19	#include <linux/sysctl.h>
	20	#include <asm/mman.h>
	21	#include <asm/pgalloc.h>
	22	#include <asm/tlb.h>
	23	#include <asm/tlbflush.h>
	24
	25	unsigned int hpage_shift=HPAGE_SHIFT_DEFAULT;
	26
	27	static pte_t *
	28	huge_pte_alloc (struct mm_struct *mm, unsigned long addr)
	29	{
	30	unsigned long taddr = htlbpage_to_page(addr);
	31	pgd_t *pgd;
	32	pud_t *pud;
	33	pmd_t *pmd;
	34	pte_t *pte = NULL;
	35
	36	pgd = pgd_offset(mm, taddr);
	37	pud = pud_alloc(mm, pgd, taddr);
	38	if (pud) {
	39	pmd = pmd_alloc(mm, pud, taddr);
	40	if (pmd)
	41	pte = pte_alloc_map(mm, pmd, taddr);
	42	}
	43	return pte;
	44	}
	45
	46	static pte_t *
	47	huge_pte_offset (struct mm_struct *mm, unsigned long addr)
	48	{
	49	unsigned long taddr = htlbpage_to_page(addr);
	50	pgd_t *pgd;
	51	pud_t *pud;
	52	pmd_t *pmd;
	53	pte_t *pte = NULL;
	54
	55	pgd = pgd_offset(mm, taddr);
	56	if (pgd_present(*pgd)) {
	57	pud = pud_offset(pgd, taddr);
	58	if (pud_present(*pud)) {
	59	pmd = pmd_offset(pud, taddr);
	60	if (pmd_present(*pmd))
	61	pte = pte_offset_map(pmd, taddr);
	62	}
	63	}
	64
65	return pte;
66	}
67
68	#define mk_pte_huge(entry) { pte_val(entry) \|= _PAGE_P; }
69
70	static void
71	set_huge_pte (struct mm_struct mm, struct vm_area_struct vma,
72	struct page page, pte_t page_table, int write_access)
73	{
74	pte_t entry;
75
76	add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
77	if (write_access) {
78	entry =
79	pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
80	} else
81	entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
82	entry = pte_mkyoung(entry);
83	mk_pte_huge(entry);
84	set_pte(page_table, entry);
85	return;
86	}
87	/*
88	* This function checks for proper alignment of input addr and len parameters.
89	*/
90	int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
91	{
92	if (len & ~HPAGE_MASK)
93	return -EINVAL;
94	if (addr & ~HPAGE_MASK)
95	return -EINVAL;
96	if (REGION_NUMBER(addr) != REGION_HPAGE)
97	return -EINVAL;
98
99	return 0;
100	}
101
102	int copy_hugetlb_page_range(struct mm_struct dst, struct mm_struct src,
103	struct vm_area_struct *vma)
104	{
105	pte_t src_pte, dst_pte, entry;
106	struct page *ptepage;
107	unsigned long addr = vma->vm_start;
108	unsigned long end = vma->vm_end;
109
110	while (addr < end) {
111	dst_pte = huge_pte_alloc(dst, addr);
112	if (!dst_pte)
113	goto nomem;
114	src_pte = huge_pte_offset(src, addr);
115	entry = *src_pte;
116	ptepage = pte_page(entry);
117	get_page(ptepage);
118	set_pte(dst_pte, entry);
119	add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
120	addr += HPAGE_SIZE;
121	}
122	return 0;
123	nomem:
124	return -ENOMEM;
125	}
126
127	int
128	follow_hugetlb_page(struct mm_struct mm, struct vm_area_struct vma,
129	struct page pages, struct vm_area_struct vmas,
130	unsigned long st, int length, int i)
131	{
132	pte_t *ptep, pte;
133	unsigned long start = *st;
134	unsigned long pstart;
135	int len = *length;
136	struct page *page;
137
138	do {
139	pstart = start & HPAGE_MASK;
140	ptep = huge_pte_offset(mm, start);
141	pte = *ptep;
142
143	back1:
144	page = pte_page(pte);
145	if (pages) {
146	page += ((start & ~HPAGE_MASK) >> PAGE_SHIFT);
147	get_page(page);
148	pages[i] = page;
149	}
150	if (vmas)
151	vmas[i] = vma;
152	i++;
153	len--;
154	start += PAGE_SIZE;
155	if (((start & HPAGE_MASK) == pstart) && len &&
156	(start < vma->vm_end))
157	goto back1;
158	} while (len && start < vma->vm_end);
159	*length = len;
160	*st = start;
161	return i;
162	}
163
164	struct page follow_huge_addr(struct mm_struct mm, unsigned long addr, int write)
165	{
166	struct page *page;
167	pte_t *ptep;
168
169	if (REGION_NUMBER(addr) != REGION_HPAGE)
170	return ERR_PTR(-EINVAL);
171
172	ptep = huge_pte_offset(mm, addr);
173	if (!ptep \|\| pte_none(*ptep))
174	return NULL;
175	page = pte_page(*ptep);
176	page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
177	return page;
178	}
179	int pmd_huge(pmd_t pmd)
180	{
181	return 0;
182	}
183	struct page *
184	follow_huge_pmd(struct mm_struct mm, unsigned long address, pmd_t pmd, int write)
185	{
186	return NULL;
187	}
188
3bf5ee95 HD	189	void hugetlb_free_pgd_range(struct mmu_gather **tlb,
	190	unsigned long addr, unsigned long end,
	191	unsigned long floor, unsigned long ceiling)
1da177e4	192	{
3bf5ee95 HD	193	/*
	194	* This is called only when is_hugepage_only_range(addr,),
	195	* and it follows that is_hugepage_only_range(end,) also.
	196	*
	197	* The offset of these addresses from the base of the hugetlb
	198	* region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
	199	* the standard free_pgd_range will free the right page tables.
	200	*
	201	* If floor and ceiling are also in the hugetlb region, they
	202	* must likewise be scaled down; but if outside, left unchanged.
	203	*/
	204
	205	addr = htlbpage_to_page(addr);
	206	end = htlbpage_to_page(end);
	207	if (is_hugepage_only_range(tlb->mm, floor, HPAGE_SIZE))
	208	floor = htlbpage_to_page(floor);
	209	if (is_hugepage_only_range(tlb->mm, ceiling, HPAGE_SIZE))
	210	ceiling = htlbpage_to_page(ceiling);
	211
	212	free_pgd_range(tlb, addr, end, floor, ceiling);
1da177e4 LT	213	}
	214
	215	void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
	216	{
	217	struct mm_struct *mm = vma->vm_mm;
	218	unsigned long address;
	219	pte_t *pte;
	220	struct page *page;
	221
	222	BUG_ON(start & (HPAGE_SIZE - 1));
	223	BUG_ON(end & (HPAGE_SIZE - 1));
	224
	225	for (address = start; address < end; address += HPAGE_SIZE) {
	226	pte = huge_pte_offset(mm, address);
	227	if (pte_none(*pte))
	228	continue;
	229	page = pte_page(*pte);
	230	put_page(page);
	231	pte_clear(mm, address, pte);
	232	}
	233	add_mm_counter(mm, rss, - ((end - start) >> PAGE_SHIFT));
	234	flush_tlb_range(vma, start, end);
	235	}
	236
	237	int hugetlb_prefault(struct address_space mapping, struct vm_area_struct vma)
	238	{
	239	struct mm_struct *mm = current->mm;
	240	unsigned long addr;
	241	int ret = 0;
	242
	243	BUG_ON(vma->vm_start & ~HPAGE_MASK);
	244	BUG_ON(vma->vm_end & ~HPAGE_MASK);
	245
	246	spin_lock(&mm->page_table_lock);
	247	for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
	248	unsigned long idx;
	249	pte_t *pte = huge_pte_alloc(mm, addr);
	250	struct page *page;
	251
	252	if (!pte) {
	253	ret = -ENOMEM;
	254	goto out;
	255	}
	256	if (!pte_none(*pte))
	257	continue;
	258
	259	idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
	260	+ (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
	261	page = find_get_page(mapping, idx);
	262	if (!page) {
	263	/* charge the fs quota first */
	264	if (hugetlb_get_quota(mapping)) {
	265	ret = -ENOMEM;
	266	goto out;
	267	}
	268	page = alloc_huge_page();
	269	if (!page) {
	270	hugetlb_put_quota(mapping);
	271	ret = -ENOMEM;
	272	goto out;
	273	}
	274	ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
	275	if (! ret) {
	276	unlock_page(page);
277	} else {
278	hugetlb_put_quota(mapping);
279	page_cache_release(page);
280	goto out;
281	}
282	}
283	set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE);
284	}
285	out:
286	spin_unlock(&mm->page_table_lock);
287	return ret;
288	}
289
290	unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
291	unsigned long pgoff, unsigned long flags)
292	{
293	struct vm_area_struct *vmm;
294
295	if (len > RGN_MAP_LIMIT)
296	return -ENOMEM;
297	if (len & ~HPAGE_MASK)
298	return -EINVAL;
299	/* This code assumes that REGION_HPAGE != 0. */
300	if ((REGION_NUMBER(addr) != REGION_HPAGE) \|\| (addr & (HPAGE_SIZE - 1)))
301	addr = HPAGE_REGION_BASE;
302	else
303	addr = ALIGN(addr, HPAGE_SIZE);
304	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
305	/* At this point: (!vmm \|\| addr < vmm->vm_end). */
306	if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
307	return -ENOMEM;
308	if (!vmm \|\| (addr + len) <= vmm->vm_start)
309	return addr;
310	addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
311	}
312	}
313
314	static int __init hugetlb_setup_sz(char *str)
315	{
316	u64 tr_pages;
317	unsigned long long size;
318
319	if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
320	/*
321	* shouldn't happen, but just in case.
322	*/
323	tr_pages = 0x15557000UL;
324
325	size = memparse(str, &str);
326	if (*str \|\| (size & (size-1)) \|\| !(tr_pages & size) \|\|
327	size <= PAGE_SIZE \|\|
328	size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
329	printk(KERN_WARNING "Invalid huge page size specified\n");
330	return 1;
331	}
332
333	hpage_shift = __ffs(size);
334	/*
335	* boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
336	* override here with new page shift.
337	*/
338	ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
339	return 1;
340	}
341	__setup("hugepagesz=", hugetlb_setup_sz);