[linux-2.6-block.git] / arch / s390 / mm / hugetlbpage.c

/*
 *  IBM System z Huge TLB Page Support for Kernel.
 *
 *    Copyright 2007 IBM Corp.
 *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
 */

#include <linux/mm.h>
#include <linux/hugetlb.h>


void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
				   pte_t *pteptr, pte_t pteval)
{
	pmd_t *pmdp = (pmd_t *) pteptr;
	unsigned long mask;

	if (!MACHINE_HAS_HPAGE) {
		pteptr = (pte_t *) pte_page(pteval)[1].index;
		mask = pte_val(pteval) &
				(_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
		pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask;
	}

	pmd_val(*pmdp) = pte_val(pteval);
}

int arch_prepare_hugepage(struct page *page)
{
	unsigned long addr = page_to_phys(page);
	pte_t pte;
	pte_t *ptep;
	int i;

	if (MACHINE_HAS_HPAGE)
		return 0;

	ptep = (pte_t *) pte_alloc_one(&init_mm, address);
	if (!ptep)
		return -ENOMEM;

	pte = mk_pte(page, PAGE_RW);
	for (i = 0; i < PTRS_PER_PTE; i++) {
		set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
		pte_val(pte) += PAGE_SIZE;
	}
	page[1].index = (unsigned long) ptep;
	return 0;
}

void arch_release_hugepage(struct page *page)
{
	pte_t *ptep;

	if (MACHINE_HAS_HPAGE)
		return;

	ptep = (pte_t *) page[1].index;
	if (!ptep)
		return;
	page_table_free(&init_mm, (unsigned long *) ptep);
	page[1].index = 0;
}

pte_t *huge_pte_alloc(struct mm_struct *mm,
			unsigned long addr, unsigned long sz)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp = NULL;

	pgdp = pgd_offset(mm, addr);
	pudp = pud_alloc(mm, pgdp, addr);
	if (pudp)
		pmdp = pmd_alloc(mm, pudp, addr);
	return (pte_t *) pmdp;
}

pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp = NULL;

	pgdp = pgd_offset(mm, addr);
	if (pgd_present(*pgdp)) {
		pudp = pud_offset(pgdp, addr);
		if (pud_present(*pudp))
			pmdp = pmd_offset(pudp, addr);
	}
	return (pte_t *) pmdp;
}

int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
	return 0;
}

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

int pmd_huge(pmd_t pmd)
{
	if (!MACHINE_HAS_HPAGE)
		return 0;

	return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
}

int pud_huge(pud_t pud)
{
	return 0;
}

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

	if (!MACHINE_HAS_HPAGE)
		return NULL;

	page = pmd_page(*pmdp);
	if (page)
		page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
	return page;
}
Commit	Line	Data
53492b1d GS	1	/*
	2	* IBM System z Huge TLB Page Support for Kernel.
	3	*
	4	* Copyright 2007 IBM Corp.
	5	* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
	6	*/
	7
	8	#include <linux/mm.h>
	9	#include <linux/hugetlb.h>
	10
	11
	12	void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
	13	pte_t *pteptr, pte_t pteval)
	14	{
	15	pmd_t pmdp = (pmd_t ) pteptr;
53492b1d GS	16	unsigned long mask;
	17
	18	if (!MACHINE_HAS_HPAGE) {
	19	pteptr = (pte_t *) pte_page(pteval)[1].index;
	20	mask = pte_val(pteval) &
	21	(_SEGMENT_ENTRY_INV \| _SEGMENT_ENTRY_RO);
	22	pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) \| mask;
53492b1d GS	23	}
	24
	25	pmd_val(*pmdp) = pte_val(pteval);
53492b1d GS	26	}
	27
	28	int arch_prepare_hugepage(struct page *page)
	29	{
	30	unsigned long addr = page_to_phys(page);
	31	pte_t pte;
	32	pte_t *ptep;
	33	int i;
	34
	35	if (MACHINE_HAS_HPAGE)
	36	return 0;
	37
	38	ptep = (pte_t *) pte_alloc_one(&init_mm, address);
	39	if (!ptep)
	40	return -ENOMEM;
	41
	42	pte = mk_pte(page, PAGE_RW);
	43	for (i = 0; i < PTRS_PER_PTE; i++) {
	44	set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
	45	pte_val(pte) += PAGE_SIZE;
	46	}
	47	page[1].index = (unsigned long) ptep;
	48	return 0;
	49	}
	50
	51	void arch_release_hugepage(struct page *page)
	52	{
	53	pte_t *ptep;
	54
	55	if (MACHINE_HAS_HPAGE)
	56	return;
	57
	58	ptep = (pte_t *) page[1].index;
	59	if (!ptep)
	60	return;
80217147	61	page_table_free(&init_mm, (unsigned long *) ptep);
53492b1d GS	62	page[1].index = 0;
	63	}
	64
a5516438 AK	65	pte_t huge_pte_alloc(struct mm_struct mm,
a5516438 AK	66	unsigned long addr, unsigned long sz)
53492b1d GS	67	{
	68	pgd_t *pgdp;
	69	pud_t *pudp;
	70	pmd_t *pmdp = NULL;
	71
	72	pgdp = pgd_offset(mm, addr);
	73	pudp = pud_alloc(mm, pgdp, addr);
	74	if (pudp)
	75	pmdp = pmd_alloc(mm, pudp, addr);
	76	return (pte_t *) pmdp;
	77	}
	78
	79	pte_t huge_pte_offset(struct mm_struct mm, unsigned long addr)
	80	{
	81	pgd_t *pgdp;
	82	pud_t *pudp;
	83	pmd_t *pmdp = NULL;
	84
	85	pgdp = pgd_offset(mm, addr);
	86	if (pgd_present(*pgdp)) {
	87	pudp = pud_offset(pgdp, addr);
	88	if (pud_present(*pudp))
	89	pmdp = pmd_offset(pudp, addr);
	90	}
	91	return (pte_t *) pmdp;
	92	}
	93
	94	int huge_pmd_unshare(struct mm_struct mm, unsigned long addr, pte_t *ptep)
	95	{
	96	return 0;
	97	}
	98
	99	struct page follow_huge_addr(struct mm_struct mm, unsigned long address,
	100	int write)
	101	{
	102	return ERR_PTR(-EINVAL);
	103	}
	104
	105	int pmd_huge(pmd_t pmd)
	106	{
	107	if (!MACHINE_HAS_HPAGE)
	108	return 0;
	109
	110	return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
	111	}
	112
ceb86879 AK	113	int pud_huge(pud_t pud)
	114	{
	115	return 0;
	116	}
	117
53492b1d GS	118	struct page follow_huge_pmd(struct mm_struct mm, unsigned long address,
	119	pmd_t *pmdp, int write)
	120	{
	121	struct page *page;
	122
	123	if (!MACHINE_HAS_HPAGE)
	124	return NULL;
	125
	126	page = pmd_page(*pmdp);
	127	if (page)
	128	page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
	129	return page;
	130	}