CONFIG_FILE_LOCKING should not depend on CONFIG_BLOCK
[sfrench/cifs-2.6.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/slab.h>
18 #include <linux/sysctl.h>
19 #include <linux/log2.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 EXPORT_SYMBOL(hpage_shift);
27
28 pte_t *
29 huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
30 {
31         unsigned long taddr = htlbpage_to_page(addr);
32         pgd_t *pgd;
33         pud_t *pud;
34         pmd_t *pmd;
35         pte_t *pte = NULL;
36
37         pgd = pgd_offset(mm, taddr);
38         pud = pud_alloc(mm, pgd, taddr);
39         if (pud) {
40                 pmd = pmd_alloc(mm, pud, taddr);
41                 if (pmd)
42                         pte = pte_alloc_map(mm, pmd, taddr);
43         }
44         return pte;
45 }
46
47 pte_t *
48 huge_pte_offset (struct mm_struct *mm, unsigned long addr)
49 {
50         unsigned long taddr = htlbpage_to_page(addr);
51         pgd_t *pgd;
52         pud_t *pud;
53         pmd_t *pmd;
54         pte_t *pte = NULL;
55
56         pgd = pgd_offset(mm, taddr);
57         if (pgd_present(*pgd)) {
58                 pud = pud_offset(pgd, taddr);
59                 if (pud_present(*pud)) {
60                         pmd = pmd_offset(pud, taddr);
61                         if (pmd_present(*pmd))
62                                 pte = pte_offset_map(pmd, taddr);
63                 }
64         }
65
66         return pte;
67 }
68
69 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
70 {
71         return 0;
72 }
73
74 #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
75
76 /*
77  * Don't actually need to do any preparation, but need to make sure
78  * the address is in the right region.
79  */
80 int prepare_hugepage_range(struct file *file,
81                         unsigned long addr, unsigned long len)
82 {
83         if (len & ~HPAGE_MASK)
84                 return -EINVAL;
85         if (addr & ~HPAGE_MASK)
86                 return -EINVAL;
87         if (REGION_NUMBER(addr) != RGN_HPAGE)
88                 return -EINVAL;
89
90         return 0;
91 }
92
93 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
94 {
95         struct page *page;
96         pte_t *ptep;
97
98         if (REGION_NUMBER(addr) != RGN_HPAGE)
99                 return ERR_PTR(-EINVAL);
100
101         ptep = huge_pte_offset(mm, addr);
102         if (!ptep || pte_none(*ptep))
103                 return NULL;
104         page = pte_page(*ptep);
105         page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
106         return page;
107 }
108 int pmd_huge(pmd_t pmd)
109 {
110         return 0;
111 }
112
113 int pud_huge(pud_t pud)
114 {
115         return 0;
116 }
117
118 struct page *
119 follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
120 {
121         return NULL;
122 }
123
124 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
125                         unsigned long addr, unsigned long end,
126                         unsigned long floor, unsigned long ceiling)
127 {
128         /*
129          * This is called to free hugetlb page tables.
130          *
131          * The offset of these addresses from the base of the hugetlb
132          * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
133          * the standard free_pgd_range will free the right page tables.
134          *
135          * If floor and ceiling are also in the hugetlb region, they
136          * must likewise be scaled down; but if outside, left unchanged.
137          */
138
139         addr = htlbpage_to_page(addr);
140         end  = htlbpage_to_page(end);
141         if (REGION_NUMBER(floor) == RGN_HPAGE)
142                 floor = htlbpage_to_page(floor);
143         if (REGION_NUMBER(ceiling) == RGN_HPAGE)
144                 ceiling = htlbpage_to_page(ceiling);
145
146         free_pgd_range(tlb, addr, end, floor, ceiling);
147 }
148
149 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
150                 unsigned long pgoff, unsigned long flags)
151 {
152         struct vm_area_struct *vmm;
153
154         if (len > RGN_MAP_LIMIT)
155                 return -ENOMEM;
156         if (len & ~HPAGE_MASK)
157                 return -EINVAL;
158
159         /* Handle MAP_FIXED */
160         if (flags & MAP_FIXED) {
161                 if (prepare_hugepage_range(file, addr, len))
162                         return -EINVAL;
163                 return addr;
164         }
165
166         /* This code assumes that RGN_HPAGE != 0. */
167         if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
168                 addr = HPAGE_REGION_BASE;
169         else
170                 addr = ALIGN(addr, HPAGE_SIZE);
171         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
172                 /* At this point:  (!vmm || addr < vmm->vm_end). */
173                 if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
174                         return -ENOMEM;
175                 if (!vmm || (addr + len) <= vmm->vm_start)
176                         return addr;
177                 addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
178         }
179 }
180
181 static int __init hugetlb_setup_sz(char *str)
182 {
183         u64 tr_pages;
184         unsigned long long size;
185
186         if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
187                 /*
188                  * shouldn't happen, but just in case.
189                  */
190                 tr_pages = 0x15557000UL;
191
192         size = memparse(str, &str);
193         if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
194                 size <= PAGE_SIZE ||
195                 size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
196                 printk(KERN_WARNING "Invalid huge page size specified\n");
197                 return 1;
198         }
199
200         hpage_shift = __ffs(size);
201         /*
202          * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
203          * override here with new page shift.
204          */
205         ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
206         return 0;
207 }
208 early_param("hugepagesz", hugetlb_setup_sz);