[deliverable/linux.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;
	pte_t shadow_pteval = pteval;
	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;
		if (mm->context.noexec) {
			pteptr += PTRS_PER_PTE;
			pte_val(shadow_pteval) =
					(_SEGMENT_ENTRY + __pa(pteptr)) | mask;
		}
	}

	pmd_val(*pmdp) = pte_val(pteval);
	if (mm->context.noexec) {
		pmdp = get_shadow_table(pmdp);
		pmd_val(*pmdp) = pte_val(shadow_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;
	pte_free(&init_mm, ptep);
	page[1].index = 0;
}

pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
{
	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);
}

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;
	16	pte_t shadow_pteval = pteval;
	17	unsigned long mask;
	18
	19	if (!MACHINE_HAS_HPAGE) {
	20	pteptr = (pte_t *) pte_page(pteval)[1].index;
	21	mask = pte_val(pteval) &
	22	(_SEGMENT_ENTRY_INV \| _SEGMENT_ENTRY_RO);
	23	pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) \| mask;
	24	if (mm->context.noexec) {
	25	pteptr += PTRS_PER_PTE;
	26	pte_val(shadow_pteval) =
	27	(_SEGMENT_ENTRY + __pa(pteptr)) \| mask;
	28	}
	29	}
	30
	31	pmd_val(*pmdp) = pte_val(pteval);
	32	if (mm->context.noexec) {
	33	pmdp = get_shadow_table(pmdp);
	34	pmd_val(*pmdp) = pte_val(shadow_pteval);
	35	}
	36	}
	37
	38	int arch_prepare_hugepage(struct page *page)
	39	{
	40	unsigned long addr = page_to_phys(page);
	41	pte_t pte;
	42	pte_t *ptep;
	43	int i;
	44
	45	if (MACHINE_HAS_HPAGE)
	46	return 0;
	47
	48	ptep = (pte_t *) pte_alloc_one(&init_mm, address);
	49	if (!ptep)
	50	return -ENOMEM;
	51
	52	pte = mk_pte(page, PAGE_RW);
	53	for (i = 0; i < PTRS_PER_PTE; i++) {
	54	set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
	55	pte_val(pte) += PAGE_SIZE;
	56	}
	57	page[1].index = (unsigned long) ptep;
	58	return 0;
	59	}
	60
	61	void arch_release_hugepage(struct page *page)
	62	{
	63	pte_t *ptep;
	64
65	if (MACHINE_HAS_HPAGE)
66	return;
67
68	ptep = (pte_t *) page[1].index;
69	if (!ptep)
70	return;
71	pte_free(&init_mm, ptep);
72	page[1].index = 0;
73	}
74
75	pte_t huge_pte_alloc(struct mm_struct mm, unsigned long addr)
76	{
77	pgd_t *pgdp;
78	pud_t *pudp;
79	pmd_t *pmdp = NULL;
80
81	pgdp = pgd_offset(mm, addr);
82	pudp = pud_alloc(mm, pgdp, addr);
83	if (pudp)
84	pmdp = pmd_alloc(mm, pudp, addr);
85	return (pte_t *) pmdp;
86	}
87
88	pte_t huge_pte_offset(struct mm_struct mm, unsigned long addr)
89	{
90	pgd_t *pgdp;
91	pud_t *pudp;
92	pmd_t *pmdp = NULL;
93
94	pgdp = pgd_offset(mm, addr);
95	if (pgd_present(*pgdp)) {
96	pudp = pud_offset(pgdp, addr);
97	if (pud_present(*pudp))
98	pmdp = pmd_offset(pudp, addr);
99	}
100	return (pte_t *) pmdp;
101	}
102
103	int huge_pmd_unshare(struct mm_struct mm, unsigned long addr, pte_t *ptep)
104	{
105	return 0;
106	}
107
108	struct page follow_huge_addr(struct mm_struct mm, unsigned long address,
109	int write)
110	{
111	return ERR_PTR(-EINVAL);
112	}
113
114	int pmd_huge(pmd_t pmd)
115	{
116	if (!MACHINE_HAS_HPAGE)
117	return 0;
118
119	return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
120	}
121
122	struct page follow_huge_pmd(struct mm_struct mm, unsigned long address,
123	pmd_t *pmdp, int write)
124	{
125	struct page *page;
126
127	if (!MACHINE_HAS_HPAGE)
128	return NULL;
129
130	page = pmd_page(*pmdp);
131	if (page)
132	page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
133	return page;
134	}