hugetlb: introduce pud_huge
[linux-2.6/mini2440.git] / arch / ia64 / mm / hugetlbpage.c
blobc45fc7f5a979b6064b7e8a403de1922b21adf6df
1 /*
2 * IA-64 Huge TLB Page Support for Kernel.
4 * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
5 * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
7 * Sep, 2003: add numa support
8 * Feb, 2004: dynamic hugetlb page size via boot parameter
9 */
11 #include <linux/init.h>
12 #include <linux/fs.h>
13 #include <linux/mm.h>
14 #include <linux/hugetlb.h>
15 #include <linux/pagemap.h>
16 #include <linux/slab.h>
17 #include <linux/sysctl.h>
18 #include <linux/log2.h>
19 #include <asm/mman.h>
20 #include <asm/pgalloc.h>
21 #include <asm/tlb.h>
22 #include <asm/tlbflush.h>
24 unsigned int hpage_shift=HPAGE_SHIFT_DEFAULT;
26 pte_t *
27 huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
29 unsigned long taddr = htlbpage_to_page(addr);
30 pgd_t *pgd;
31 pud_t *pud;
32 pmd_t *pmd;
33 pte_t *pte = NULL;
35 pgd = pgd_offset(mm, taddr);
36 pud = pud_alloc(mm, pgd, taddr);
37 if (pud) {
38 pmd = pmd_alloc(mm, pud, taddr);
39 if (pmd)
40 pte = pte_alloc_map(mm, pmd, taddr);
42 return pte;
45 pte_t *
46 huge_pte_offset (struct mm_struct *mm, unsigned long addr)
48 unsigned long taddr = htlbpage_to_page(addr);
49 pgd_t *pgd;
50 pud_t *pud;
51 pmd_t *pmd;
52 pte_t *pte = NULL;
54 pgd = pgd_offset(mm, taddr);
55 if (pgd_present(*pgd)) {
56 pud = pud_offset(pgd, taddr);
57 if (pud_present(*pud)) {
58 pmd = pmd_offset(pud, taddr);
59 if (pmd_present(*pmd))
60 pte = pte_offset_map(pmd, taddr);
64 return pte;
67 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
69 return 0;
72 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
75 * Don't actually need to do any preparation, but need to make sure
76 * the address is in the right region.
78 int prepare_hugepage_range(struct file *file,
79 unsigned long addr, unsigned long len)
81 if (len & ~HPAGE_MASK)
82 return -EINVAL;
83 if (addr & ~HPAGE_MASK)
84 return -EINVAL;
85 if (REGION_NUMBER(addr) != RGN_HPAGE)
86 return -EINVAL;
88 return 0;
91 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
93 struct page *page;
94 pte_t *ptep;
96 if (REGION_NUMBER(addr) != RGN_HPAGE)
97 return ERR_PTR(-EINVAL);
99 ptep = huge_pte_offset(mm, addr);
100 if (!ptep || pte_none(*ptep))
101 return NULL;
102 page = pte_page(*ptep);
103 page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
104 return page;
106 int pmd_huge(pmd_t pmd)
108 return 0;
111 int pud_huge(pud_t pud)
113 return 0;
116 struct page *
117 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
119 return NULL;
122 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
123 unsigned long addr, unsigned long end,
124 unsigned long floor, unsigned long ceiling)
127 * This is called to free hugetlb page tables.
129 * The offset of these addresses from the base of the hugetlb
130 * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
131 * the standard free_pgd_range will free the right page tables.
133 * If floor and ceiling are also in the hugetlb region, they
134 * must likewise be scaled down; but if outside, left unchanged.
137 addr = htlbpage_to_page(addr);
138 end = htlbpage_to_page(end);
139 if (REGION_NUMBER(floor) == RGN_HPAGE)
140 floor = htlbpage_to_page(floor);
141 if (REGION_NUMBER(ceiling) == RGN_HPAGE)
142 ceiling = htlbpage_to_page(ceiling);
144 free_pgd_range(tlb, addr, end, floor, ceiling);
147 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
148 unsigned long pgoff, unsigned long flags)
150 struct vm_area_struct *vmm;
152 if (len > RGN_MAP_LIMIT)
153 return -ENOMEM;
154 if (len & ~HPAGE_MASK)
155 return -EINVAL;
157 /* Handle MAP_FIXED */
158 if (flags & MAP_FIXED) {
159 if (prepare_hugepage_range(file, addr, len))
160 return -EINVAL;
161 return addr;
164 /* This code assumes that RGN_HPAGE != 0. */
165 if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
166 addr = HPAGE_REGION_BASE;
167 else
168 addr = ALIGN(addr, HPAGE_SIZE);
169 for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
170 /* At this point: (!vmm || addr < vmm->vm_end). */
171 if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
172 return -ENOMEM;
173 if (!vmm || (addr + len) <= vmm->vm_start)
174 return addr;
175 addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
179 static int __init hugetlb_setup_sz(char *str)
181 u64 tr_pages;
182 unsigned long long size;
184 if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
186 * shouldn't happen, but just in case.
188 tr_pages = 0x15557000UL;
190 size = memparse(str, &str);
191 if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
192 size <= PAGE_SIZE ||
193 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
194 printk(KERN_WARNING "Invalid huge page size specified\n");
195 return 1;
198 hpage_shift = __ffs(size);
200 * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
201 * override here with new page shift.
203 ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
204 return 0;
206 early_param("hugepagesz", hugetlb_setup_sz);