5a1f831b2de1b0ef92032a0ed34dff5a8ff48fcb
[linux-3.10.git] / arch / sparc64 / mm / hugetlbpage.c
1 /*
2  * SPARC64 Huge TLB page support.
3  *
4  * Copyright (C) 2002, 2003 David S. Miller (davem@redhat.com)
5  */
6
7 #include <linux/config.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include <linux/hugetlb.h>
13 #include <linux/pagemap.h>
14 #include <linux/smp_lock.h>
15 #include <linux/slab.h>
16 #include <linux/sysctl.h>
17
18 #include <asm/mman.h>
19 #include <asm/pgalloc.h>
20 #include <asm/tlb.h>
21 #include <asm/tlbflush.h>
22 #include <asm/cacheflush.h>
23 #include <asm/mmu_context.h>
24
25 static pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
26 {
27         pgd_t *pgd;
28         pud_t *pud;
29         pmd_t *pmd;
30         pte_t *pte = NULL;
31
32         pgd = pgd_offset(mm, addr);
33         if (pgd) {
34                 pud = pud_offset(pgd, addr);
35                 if (pud) {
36                         pmd = pmd_alloc(mm, pud, addr);
37                         if (pmd)
38                                 pte = pte_alloc_map(mm, pmd, addr);
39                 }
40         }
41         return pte;
42 }
43
44 static pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
45 {
46         pgd_t *pgd;
47         pud_t *pud;
48         pmd_t *pmd;
49         pte_t *pte = NULL;
50
51         pgd = pgd_offset(mm, addr);
52         if (pgd) {
53                 pud = pud_offset(pgd, addr);
54                 if (pud) {
55                         pmd = pmd_offset(pud, addr);
56                         if (pmd)
57                                 pte = pte_offset_map(pmd, addr);
58                 }
59         }
60         return pte;
61 }
62
63 #define mk_pte_huge(entry) do { pte_val(entry) |= _PAGE_SZHUGE; } while (0)
64
65 static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma,
66                          unsigned long addr,
67                          struct page *page, pte_t * page_table, int write_access)
68 {
69         unsigned long i;
70         pte_t entry;
71
72         add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
73
74         if (write_access)
75                 entry = pte_mkwrite(pte_mkdirty(mk_pte(page,
76                                                        vma->vm_page_prot)));
77         else
78                 entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
79         entry = pte_mkyoung(entry);
80         mk_pte_huge(entry);
81
82         for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
83                 set_pte_at(mm, addr, page_table, entry);
84                 page_table++;
85                 addr += PAGE_SIZE;
86
87                 pte_val(entry) += PAGE_SIZE;
88         }
89 }
90
91 /*
92  * This function checks for proper alignment of input addr and len parameters.
93  */
94 int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
95 {
96         if (len & ~HPAGE_MASK)
97                 return -EINVAL;
98         if (addr & ~HPAGE_MASK)
99                 return -EINVAL;
100         return 0;
101 }
102
103 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
104                             struct vm_area_struct *vma)
105 {
106         pte_t *src_pte, *dst_pte, entry;
107         struct page *ptepage;
108         unsigned long addr = vma->vm_start;
109         unsigned long end = vma->vm_end;
110         int i;
111
112         while (addr < end) {
113                 dst_pte = huge_pte_alloc(dst, addr);
114                 if (!dst_pte)
115                         goto nomem;
116                 src_pte = huge_pte_offset(src, addr);
117                 BUG_ON(!src_pte || pte_none(*src_pte));
118                 entry = *src_pte;
119                 ptepage = pte_page(entry);
120                 get_page(ptepage);
121                 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
122                         set_pte_at(dst, addr, dst_pte, entry);
123                         pte_val(entry) += PAGE_SIZE;
124                         dst_pte++;
125                         addr += PAGE_SIZE;
126                 }
127                 add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
128         }
129         return 0;
130
131 nomem:
132         return -ENOMEM;
133 }
134
135 int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
136                         struct page **pages, struct vm_area_struct **vmas,
137                         unsigned long *position, int *length, int i)
138 {
139         unsigned long vaddr = *position;
140         int remainder = *length;
141
142         WARN_ON(!is_vm_hugetlb_page(vma));
143
144         while (vaddr < vma->vm_end && remainder) {
145                 if (pages) {
146                         pte_t *pte;
147                         struct page *page;
148
149                         pte = huge_pte_offset(mm, vaddr);
150
151                         /* hugetlb should be locked, and hence, prefaulted */
152                         BUG_ON(!pte || pte_none(*pte));
153
154                         page = pte_page(*pte);
155
156                         WARN_ON(!PageCompound(page));
157
158                         get_page(page);
159                         pages[i] = page;
160                 }
161
162                 if (vmas)
163                         vmas[i] = vma;
164
165                 vaddr += PAGE_SIZE;
166                 --remainder;
167                 ++i;
168         }
169
170         *length = remainder;
171         *position = vaddr;
172
173         return i;
174 }
175
176 struct page *follow_huge_addr(struct mm_struct *mm,
177                               unsigned long address, int write)
178 {
179         return ERR_PTR(-EINVAL);
180 }
181
182 int pmd_huge(pmd_t pmd)
183 {
184         return 0;
185 }
186
187 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
188                              pmd_t *pmd, int write)
189 {
190         return NULL;
191 }
192
193 void unmap_hugepage_range(struct vm_area_struct *vma,
194                           unsigned long start, unsigned long end)
195 {
196         struct mm_struct *mm = vma->vm_mm;
197         unsigned long address;
198         pte_t *pte;
199         struct page *page;
200         int i;
201
202         BUG_ON(start & (HPAGE_SIZE - 1));
203         BUG_ON(end & (HPAGE_SIZE - 1));
204
205         for (address = start; address < end; address += HPAGE_SIZE) {
206                 pte = huge_pte_offset(mm, address);
207                 BUG_ON(!pte);
208                 if (pte_none(*pte))
209                         continue;
210                 page = pte_page(*pte);
211                 put_page(page);
212                 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
213                         pte_clear(mm, address+(i*PAGE_SIZE), pte);
214                         pte++;
215                 }
216         }
217         add_mm_counter(mm, rss, -((end - start) >> PAGE_SHIFT));
218         flush_tlb_range(vma, start, end);
219 }
220
221 static void context_reload(void *__data)
222 {
223         struct mm_struct *mm = __data;
224
225         if (mm == current->mm)
226                 load_secondary_context(mm);
227 }
228
229 int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
230 {
231         struct mm_struct *mm = current->mm;
232         unsigned long addr;
233         int ret = 0;
234
235         /* On UltraSPARC-III+ and later, configure the second half of
236          * the Data-TLB for huge pages.
237          */
238         if (tlb_type == cheetah_plus) {
239                 unsigned long ctx;
240
241                 spin_lock(&ctx_alloc_lock);
242                 ctx = mm->context.sparc64_ctx_val;
243                 ctx &= ~CTX_PGSZ_MASK;
244                 ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT;
245                 ctx |= CTX_PGSZ_HUGE << CTX_PGSZ1_SHIFT;
246
247                 if (ctx != mm->context.sparc64_ctx_val) {
248                         /* When changing the page size fields, we
249                          * must perform a context flush so that no
250                          * stale entries match.  This flush must
251                          * occur with the original context register
252                          * settings.
253                          */
254                         do_flush_tlb_mm(mm);
255
256                         /* Reload the context register of all processors
257                          * also executing in this address space.
258                          */
259                         mm->context.sparc64_ctx_val = ctx;
260                         on_each_cpu(context_reload, mm, 0, 0);
261                 }
262                 spin_unlock(&ctx_alloc_lock);
263         }
264
265         BUG_ON(vma->vm_start & ~HPAGE_MASK);
266         BUG_ON(vma->vm_end & ~HPAGE_MASK);
267
268         spin_lock(&mm->page_table_lock);
269         for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
270                 unsigned long idx;
271                 pte_t *pte = huge_pte_alloc(mm, addr);
272                 struct page *page;
273
274                 if (!pte) {
275                         ret = -ENOMEM;
276                         goto out;
277                 }
278                 if (!pte_none(*pte))
279                         continue;
280
281                 idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
282                         + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
283                 page = find_get_page(mapping, idx);
284                 if (!page) {
285                         /* charge the fs quota first */
286                         if (hugetlb_get_quota(mapping)) {
287                                 ret = -ENOMEM;
288                                 goto out;
289                         }
290                         page = alloc_huge_page();
291                         if (!page) {
292                                 hugetlb_put_quota(mapping);
293                                 ret = -ENOMEM;
294                                 goto out;
295                         }
296                         ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
297                         if (! ret) {
298                                 unlock_page(page);
299                         } else {
300                                 hugetlb_put_quota(mapping);
301                                 free_huge_page(page);
302                                 goto out;
303                         }
304                 }
305                 set_huge_pte(mm, vma, addr, page, pte, vma->vm_flags & VM_WRITE);
306         }
307 out:
308         spin_unlock(&mm->page_table_lock);
309         return ret;
310 }