mm: use vm_unmapped_area() in hugetlbfs on ia64 architecture
[~shefty/rdma-dev.git] / arch / ia64 / mm / hugetlbpage.c
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/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/module.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>
23
24 unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT;
25 EXPORT_SYMBOL(hpage_shift);
26
27 pte_t *
28 huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
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, NULL, pmd, taddr);
42         }
43         return pte;
44 }
45
46 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 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
69 {
70         return 0;
71 }
72
73 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
74
75 /*
76  * Don't actually need to do any preparation, but need to make sure
77  * the address is in the right region.
78  */
79 int prepare_hugepage_range(struct file *file,
80                         unsigned long addr, unsigned long len)
81 {
82         if (len & ~HPAGE_MASK)
83                 return -EINVAL;
84         if (addr & ~HPAGE_MASK)
85                 return -EINVAL;
86         if (REGION_NUMBER(addr) != RGN_HPAGE)
87                 return -EINVAL;
88
89         return 0;
90 }
91
92 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
93 {
94         struct page *page;
95         pte_t *ptep;
96
97         if (REGION_NUMBER(addr) != RGN_HPAGE)
98                 return ERR_PTR(-EINVAL);
99
100         ptep = huge_pte_offset(mm, addr);
101         if (!ptep || pte_none(*ptep))
102                 return NULL;
103         page = pte_page(*ptep);
104         page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
105         return page;
106 }
107 int pmd_huge(pmd_t pmd)
108 {
109         return 0;
110 }
111
112 int pud_huge(pud_t pud)
113 {
114         return 0;
115 }
116
117 struct page *
118 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
119 {
120         return NULL;
121 }
122
123 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
124                         unsigned long addr, unsigned long end,
125                         unsigned long floor, unsigned long ceiling)
126 {
127         /*
128          * This is called to free hugetlb page tables.
129          *
130          * The offset of these addresses from the base of the hugetlb
131          * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
132          * the standard free_pgd_range will free the right page tables.
133          *
134          * If floor and ceiling are also in the hugetlb region, they
135          * must likewise be scaled down; but if outside, left unchanged.
136          */
137
138         addr = htlbpage_to_page(addr);
139         end  = htlbpage_to_page(end);
140         if (REGION_NUMBER(floor) == RGN_HPAGE)
141                 floor = htlbpage_to_page(floor);
142         if (REGION_NUMBER(ceiling) == RGN_HPAGE)
143                 ceiling = htlbpage_to_page(ceiling);
144
145         free_pgd_range(tlb, addr, end, floor, ceiling);
146 }
147
148 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
149                 unsigned long pgoff, unsigned long flags)
150 {
151         struct vm_unmapped_area_info info;
152
153         if (len > RGN_MAP_LIMIT)
154                 return -ENOMEM;
155         if (len & ~HPAGE_MASK)
156                 return -EINVAL;
157
158         /* Handle MAP_FIXED */
159         if (flags & MAP_FIXED) {
160                 if (prepare_hugepage_range(file, addr, len))
161                         return -EINVAL;
162                 return addr;
163         }
164
165         /* This code assumes that RGN_HPAGE != 0. */
166         if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
167                 addr = HPAGE_REGION_BASE;
168
169         info.flags = 0;
170         info.length = len;
171         info.low_limit = addr;
172         info.high_limit = HPAGE_REGION_BASE + RGN_MAP_LIMIT;
173         info.align_mask = PAGE_MASK & (HPAGE_SIZE - 1);
174         info.align_offset = 0;
175         return vm_unmapped_area(&info);
176 }
177
178 static int __init hugetlb_setup_sz(char *str)
179 {
180         u64 tr_pages;
181         unsigned long long size;
182
183         if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
184                 /*
185                  * shouldn't happen, but just in case.
186                  */
187                 tr_pages = 0x15557000UL;
188
189         size = memparse(str, &str);
190         if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
191                 size <= PAGE_SIZE ||
192                 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
193                 printk(KERN_WARNING "Invalid huge page size specified\n");
194                 return 1;
195         }
196
197         hpage_shift = __ffs(size);
198         /*
199          * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
200          * override here with new page shift.
201          */
202         ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
203         return 0;
204 }
205 early_param("hugepagesz", hugetlb_setup_sz);