Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Generic hugetlb support. |
| 3 | * (C) William Irwin, April 2004 |
| 4 | */ |
| 5 | #include <linux/gfp.h> |
| 6 | #include <linux/list.h> |
| 7 | #include <linux/init.h> |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/sysctl.h> |
| 11 | #include <linux/highmem.h> |
| 12 | #include <linux/nodemask.h> |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 13 | #include <linux/pagemap.h> |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 14 | #include <linux/mempolicy.h> |
Christoph Lameter | aea47ff | 2006-01-08 01:00:57 -0800 | [diff] [blame] | 15 | #include <linux/cpuset.h> |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 16 | #include <linux/mutex.h> |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 17 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 18 | #include <asm/page.h> |
| 19 | #include <asm/pgtable.h> |
| 20 | |
| 21 | #include <linux/hugetlb.h> |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 22 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 25 | static unsigned long nr_huge_pages, free_huge_pages, reserved_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | unsigned long max_huge_pages; |
| 27 | static struct list_head hugepage_freelists[MAX_NUMNODES]; |
| 28 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; |
| 29 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 30 | /* |
| 31 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages |
| 32 | */ |
| 33 | static DEFINE_SPINLOCK(hugetlb_lock); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 34 | |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 35 | static void clear_huge_page(struct page *page, unsigned long addr) |
| 36 | { |
| 37 | int i; |
| 38 | |
| 39 | might_sleep(); |
| 40 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { |
| 41 | cond_resched(); |
| 42 | clear_user_highpage(page + i, addr); |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | static void copy_huge_page(struct page *dst, struct page *src, |
| 47 | unsigned long addr) |
| 48 | { |
| 49 | int i; |
| 50 | |
| 51 | might_sleep(); |
| 52 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { |
| 53 | cond_resched(); |
| 54 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE); |
| 55 | } |
| 56 | } |
| 57 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | static void enqueue_huge_page(struct page *page) |
| 59 | { |
| 60 | int nid = page_to_nid(page); |
| 61 | list_add(&page->lru, &hugepage_freelists[nid]); |
| 62 | free_huge_pages++; |
| 63 | free_huge_pages_node[nid]++; |
| 64 | } |
| 65 | |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 66 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
| 67 | unsigned long address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | { |
| 69 | int nid = numa_node_id(); |
| 70 | struct page *page = NULL; |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 71 | struct zonelist *zonelist = huge_zonelist(vma, address); |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 72 | struct zone **z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 74 | for (z = zonelist->zones; *z; z++) { |
| 75 | nid = (*z)->zone_pgdat->node_id; |
Christoph Lameter | aea47ff | 2006-01-08 01:00:57 -0800 | [diff] [blame] | 76 | if (cpuset_zone_allowed(*z, GFP_HIGHUSER) && |
| 77 | !list_empty(&hugepage_freelists[nid])) |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 78 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | } |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 80 | |
| 81 | if (*z) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | page = list_entry(hugepage_freelists[nid].next, |
| 83 | struct page, lru); |
| 84 | list_del(&page->lru); |
| 85 | free_huge_pages--; |
| 86 | free_huge_pages_node[nid]--; |
| 87 | } |
| 88 | return page; |
| 89 | } |
| 90 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 91 | static void free_huge_page(struct page *page) |
| 92 | { |
| 93 | BUG_ON(page_count(page)); |
| 94 | |
| 95 | INIT_LIST_HEAD(&page->lru); |
| 96 | |
| 97 | spin_lock(&hugetlb_lock); |
| 98 | enqueue_huge_page(page); |
| 99 | spin_unlock(&hugetlb_lock); |
| 100 | } |
| 101 | |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 102 | static int alloc_fresh_huge_page(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | { |
| 104 | static int nid = 0; |
| 105 | struct page *page; |
| 106 | page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, |
| 107 | HUGETLB_PAGE_ORDER); |
Paul Jackson | fdb7cc5 | 2006-03-22 00:09:10 -0800 | [diff] [blame] | 108 | nid = next_node(nid, node_online_map); |
| 109 | if (nid == MAX_NUMNODES) |
| 110 | nid = first_node(node_online_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | if (page) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 112 | page[1].lru.next = (void *)free_huge_page; /* dtor */ |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 113 | spin_lock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | nr_huge_pages++; |
| 115 | nr_huge_pages_node[page_to_nid(page)]++; |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 116 | spin_unlock(&hugetlb_lock); |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 117 | put_page(page); /* free it into the hugepage allocator */ |
| 118 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | } |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 120 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | } |
| 122 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 123 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
| 124 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | { |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 126 | struct inode *inode = vma->vm_file->f_dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | struct page *page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 128 | int use_reserve = 0; |
| 129 | unsigned long idx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
| 131 | spin_lock(&hugetlb_lock); |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 132 | |
| 133 | if (vma->vm_flags & VM_MAYSHARE) { |
| 134 | |
| 135 | /* idx = radix tree index, i.e. offset into file in |
| 136 | * HPAGE_SIZE units */ |
| 137 | idx = ((addr - vma->vm_start) >> HPAGE_SHIFT) |
| 138 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 139 | |
| 140 | /* The hugetlbfs specific inode info stores the number |
| 141 | * of "guaranteed available" (huge) pages. That is, |
| 142 | * the first 'prereserved_hpages' pages of the inode |
| 143 | * are either already instantiated, or have been |
| 144 | * pre-reserved (by hugetlb_reserve_for_inode()). Here |
| 145 | * we're in the process of instantiating the page, so |
| 146 | * we use this to determine whether to draw from the |
| 147 | * pre-reserved pool or the truly free pool. */ |
| 148 | if (idx < HUGETLBFS_I(inode)->prereserved_hpages) |
| 149 | use_reserve = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | } |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 151 | |
| 152 | if (!use_reserve) { |
| 153 | if (free_huge_pages <= reserved_huge_pages) |
| 154 | goto fail; |
| 155 | } else { |
| 156 | BUG_ON(reserved_huge_pages == 0); |
| 157 | reserved_huge_pages--; |
| 158 | } |
| 159 | |
| 160 | page = dequeue_huge_page(vma, addr); |
| 161 | if (!page) |
| 162 | goto fail; |
| 163 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | spin_unlock(&hugetlb_lock); |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 165 | set_page_refcounted(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 167 | |
| 168 | fail: |
| 169 | WARN_ON(use_reserve); /* reserved allocations shouldn't fail */ |
| 170 | spin_unlock(&hugetlb_lock); |
| 171 | return NULL; |
| 172 | } |
| 173 | |
| 174 | /* hugetlb_extend_reservation() |
| 175 | * |
| 176 | * Ensure that at least 'atleast' hugepages are, and will remain, |
| 177 | * available to instantiate the first 'atleast' pages of the given |
| 178 | * inode. If the inode doesn't already have this many pages reserved |
| 179 | * or instantiated, set aside some hugepages in the reserved pool to |
| 180 | * satisfy later faults (or fail now if there aren't enough, rather |
| 181 | * than getting the SIGBUS later). |
| 182 | */ |
| 183 | int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info, |
| 184 | unsigned long atleast) |
| 185 | { |
| 186 | struct inode *inode = &info->vfs_inode; |
| 187 | unsigned long change_in_reserve = 0; |
| 188 | int ret = 0; |
| 189 | |
| 190 | spin_lock(&hugetlb_lock); |
| 191 | read_lock_irq(&inode->i_mapping->tree_lock); |
| 192 | |
| 193 | if (info->prereserved_hpages >= atleast) |
| 194 | goto out; |
| 195 | |
| 196 | /* Because we always call this on shared mappings, none of the |
| 197 | * pages beyond info->prereserved_hpages can have been |
| 198 | * instantiated, so we need to reserve all of them now. */ |
| 199 | change_in_reserve = atleast - info->prereserved_hpages; |
| 200 | |
| 201 | if ((reserved_huge_pages + change_in_reserve) > free_huge_pages) { |
| 202 | ret = -ENOMEM; |
| 203 | goto out; |
| 204 | } |
| 205 | |
| 206 | reserved_huge_pages += change_in_reserve; |
| 207 | info->prereserved_hpages = atleast; |
| 208 | |
| 209 | out: |
| 210 | read_unlock_irq(&inode->i_mapping->tree_lock); |
| 211 | spin_unlock(&hugetlb_lock); |
| 212 | |
| 213 | return ret; |
| 214 | } |
| 215 | |
| 216 | /* hugetlb_truncate_reservation() |
| 217 | * |
| 218 | * This returns pages reserved for the given inode to the general free |
| 219 | * hugepage pool. If the inode has any pages prereserved, but not |
| 220 | * instantiated, beyond offset (atmost << HPAGE_SIZE), then release |
| 221 | * them. |
| 222 | */ |
| 223 | void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info, |
| 224 | unsigned long atmost) |
| 225 | { |
| 226 | struct inode *inode = &info->vfs_inode; |
| 227 | struct address_space *mapping = inode->i_mapping; |
| 228 | unsigned long idx; |
| 229 | unsigned long change_in_reserve = 0; |
| 230 | struct page *page; |
| 231 | |
| 232 | spin_lock(&hugetlb_lock); |
| 233 | read_lock_irq(&inode->i_mapping->tree_lock); |
| 234 | |
| 235 | if (info->prereserved_hpages <= atmost) |
| 236 | goto out; |
| 237 | |
| 238 | /* Count pages which were reserved, but not instantiated, and |
| 239 | * which we can now release. */ |
| 240 | for (idx = atmost; idx < info->prereserved_hpages; idx++) { |
| 241 | page = radix_tree_lookup(&mapping->page_tree, idx); |
| 242 | if (!page) |
| 243 | /* Pages which are already instantiated can't |
| 244 | * be unreserved (and in fact have already |
| 245 | * been removed from the reserved pool) */ |
| 246 | change_in_reserve++; |
| 247 | } |
| 248 | |
| 249 | BUG_ON(reserved_huge_pages < change_in_reserve); |
| 250 | reserved_huge_pages -= change_in_reserve; |
| 251 | info->prereserved_hpages = atmost; |
| 252 | |
| 253 | out: |
| 254 | read_unlock_irq(&inode->i_mapping->tree_lock); |
| 255 | spin_unlock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | } |
| 257 | |
| 258 | static int __init hugetlb_init(void) |
| 259 | { |
| 260 | unsigned long i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 262 | if (HPAGE_SHIFT == 0) |
| 263 | return 0; |
| 264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 266 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
| 267 | |
| 268 | for (i = 0; i < max_huge_pages; ++i) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 269 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | } |
| 272 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
| 273 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
| 274 | return 0; |
| 275 | } |
| 276 | module_init(hugetlb_init); |
| 277 | |
| 278 | static int __init hugetlb_setup(char *s) |
| 279 | { |
| 280 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 281 | max_huge_pages = 0; |
| 282 | return 1; |
| 283 | } |
| 284 | __setup("hugepages=", hugetlb_setup); |
| 285 | |
| 286 | #ifdef CONFIG_SYSCTL |
| 287 | static void update_and_free_page(struct page *page) |
| 288 | { |
| 289 | int i; |
| 290 | nr_huge_pages--; |
| 291 | nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; |
| 292 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
| 293 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
| 294 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
| 295 | 1 << PG_private | 1<< PG_writeback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | } |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 297 | page[1].lru.next = NULL; |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 298 | set_page_refcounted(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | __free_pages(page, HUGETLB_PAGE_ORDER); |
| 300 | } |
| 301 | |
| 302 | #ifdef CONFIG_HIGHMEM |
| 303 | static void try_to_free_low(unsigned long count) |
| 304 | { |
| 305 | int i, nid; |
| 306 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 307 | struct page *page, *next; |
| 308 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
| 309 | if (PageHighMem(page)) |
| 310 | continue; |
| 311 | list_del(&page->lru); |
| 312 | update_and_free_page(page); |
| 313 | nid = page_zone(page)->zone_pgdat->node_id; |
| 314 | free_huge_pages--; |
| 315 | free_huge_pages_node[nid]--; |
| 316 | if (count >= nr_huge_pages) |
| 317 | return; |
| 318 | } |
| 319 | } |
| 320 | } |
| 321 | #else |
| 322 | static inline void try_to_free_low(unsigned long count) |
| 323 | { |
| 324 | } |
| 325 | #endif |
| 326 | |
| 327 | static unsigned long set_max_huge_pages(unsigned long count) |
| 328 | { |
| 329 | while (count > nr_huge_pages) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 330 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | return nr_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | } |
| 333 | if (count >= nr_huge_pages) |
| 334 | return nr_huge_pages; |
| 335 | |
| 336 | spin_lock(&hugetlb_lock); |
| 337 | try_to_free_low(count); |
| 338 | while (count < nr_huge_pages) { |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 339 | struct page *page = dequeue_huge_page(NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | if (!page) |
| 341 | break; |
| 342 | update_and_free_page(page); |
| 343 | } |
| 344 | spin_unlock(&hugetlb_lock); |
| 345 | return nr_huge_pages; |
| 346 | } |
| 347 | |
| 348 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 349 | struct file *file, void __user *buffer, |
| 350 | size_t *length, loff_t *ppos) |
| 351 | { |
| 352 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 353 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 354 | return 0; |
| 355 | } |
| 356 | #endif /* CONFIG_SYSCTL */ |
| 357 | |
| 358 | int hugetlb_report_meminfo(char *buf) |
| 359 | { |
| 360 | return sprintf(buf, |
| 361 | "HugePages_Total: %5lu\n" |
| 362 | "HugePages_Free: %5lu\n" |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 363 | "HugePages_Rsvd: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | "Hugepagesize: %5lu kB\n", |
| 365 | nr_huge_pages, |
| 366 | free_huge_pages, |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 367 | reserved_huge_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | HPAGE_SIZE/1024); |
| 369 | } |
| 370 | |
| 371 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 372 | { |
| 373 | return sprintf(buf, |
| 374 | "Node %d HugePages_Total: %5u\n" |
| 375 | "Node %d HugePages_Free: %5u\n", |
| 376 | nid, nr_huge_pages_node[nid], |
| 377 | nid, free_huge_pages_node[nid]); |
| 378 | } |
| 379 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 381 | unsigned long hugetlb_total_pages(void) |
| 382 | { |
| 383 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
| 384 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | |
| 386 | /* |
| 387 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 388 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 389 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 390 | * this far. |
| 391 | */ |
| 392 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, |
| 393 | unsigned long address, int *unused) |
| 394 | { |
| 395 | BUG(); |
| 396 | return NULL; |
| 397 | } |
| 398 | |
| 399 | struct vm_operations_struct hugetlb_vm_ops = { |
| 400 | .nopage = hugetlb_nopage, |
| 401 | }; |
| 402 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 403 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 404 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 405 | { |
| 406 | pte_t entry; |
| 407 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 408 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 409 | entry = |
| 410 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 411 | } else { |
| 412 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
| 413 | } |
| 414 | entry = pte_mkyoung(entry); |
| 415 | entry = pte_mkhuge(entry); |
| 416 | |
| 417 | return entry; |
| 418 | } |
| 419 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 420 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 421 | unsigned long address, pte_t *ptep) |
| 422 | { |
| 423 | pte_t entry; |
| 424 | |
| 425 | entry = pte_mkwrite(pte_mkdirty(*ptep)); |
| 426 | ptep_set_access_flags(vma, address, ptep, entry, 1); |
| 427 | update_mmu_cache(vma, address, entry); |
| 428 | lazy_mmu_prot_update(entry); |
| 429 | } |
| 430 | |
| 431 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 432 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 433 | struct vm_area_struct *vma) |
| 434 | { |
| 435 | pte_t *src_pte, *dst_pte, entry; |
| 436 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 437 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 438 | int cow; |
| 439 | |
| 440 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 441 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 442 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 443 | src_pte = huge_pte_offset(src, addr); |
| 444 | if (!src_pte) |
| 445 | continue; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 446 | dst_pte = huge_pte_alloc(dst, addr); |
| 447 | if (!dst_pte) |
| 448 | goto nomem; |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 449 | spin_lock(&dst->page_table_lock); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 450 | spin_lock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 451 | if (!pte_none(*src_pte)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 452 | if (cow) |
| 453 | ptep_set_wrprotect(src, addr, src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 454 | entry = *src_pte; |
| 455 | ptepage = pte_page(entry); |
| 456 | get_page(ptepage); |
Hugh Dickins | 4294621 | 2005-10-29 18:16:05 -0700 | [diff] [blame] | 457 | add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 458 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 459 | } |
| 460 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 461 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 462 | } |
| 463 | return 0; |
| 464 | |
| 465 | nomem: |
| 466 | return -ENOMEM; |
| 467 | } |
| 468 | |
| 469 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 470 | unsigned long end) |
| 471 | { |
| 472 | struct mm_struct *mm = vma->vm_mm; |
| 473 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 474 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 475 | pte_t pte; |
| 476 | struct page *page; |
| 477 | |
| 478 | WARN_ON(!is_vm_hugetlb_page(vma)); |
| 479 | BUG_ON(start & ~HPAGE_MASK); |
| 480 | BUG_ON(end & ~HPAGE_MASK); |
| 481 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 482 | spin_lock(&mm->page_table_lock); |
| 483 | |
Hugh Dickins | 365e9c87 | 2005-10-29 18:16:18 -0700 | [diff] [blame] | 484 | /* Update high watermark before we lower rss */ |
| 485 | update_hiwater_rss(mm); |
| 486 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 487 | for (address = start; address < end; address += HPAGE_SIZE) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 488 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 489 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 490 | continue; |
| 491 | |
| 492 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 493 | if (pte_none(pte)) |
| 494 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 495 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 496 | page = pte_page(pte); |
| 497 | put_page(page); |
Hugh Dickins | 4294621 | 2005-10-29 18:16:05 -0700 | [diff] [blame] | 498 | add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE)); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 499 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 500 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 502 | flush_tlb_range(vma, start, end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 504 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 505 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
| 506 | unsigned long address, pte_t *ptep, pte_t pte) |
| 507 | { |
| 508 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 509 | int avoidcopy; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 510 | |
| 511 | old_page = pte_page(pte); |
| 512 | |
| 513 | /* If no-one else is actually using this page, avoid the copy |
| 514 | * and just make the page writable */ |
| 515 | avoidcopy = (page_count(old_page) == 1); |
| 516 | if (avoidcopy) { |
| 517 | set_huge_ptep_writable(vma, address, ptep); |
| 518 | return VM_FAULT_MINOR; |
| 519 | } |
| 520 | |
| 521 | page_cache_get(old_page); |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 522 | new_page = alloc_huge_page(vma, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 523 | |
| 524 | if (!new_page) { |
| 525 | page_cache_release(old_page); |
Christoph Lameter | 0df420d | 2006-02-07 12:58:30 -0800 | [diff] [blame] | 526 | return VM_FAULT_OOM; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 527 | } |
| 528 | |
| 529 | spin_unlock(&mm->page_table_lock); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 530 | copy_huge_page(new_page, old_page, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 531 | spin_lock(&mm->page_table_lock); |
| 532 | |
| 533 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); |
| 534 | if (likely(pte_same(*ptep, pte))) { |
| 535 | /* Break COW */ |
| 536 | set_huge_pte_at(mm, address, ptep, |
| 537 | make_huge_pte(vma, new_page, 1)); |
| 538 | /* Make the old page be freed below */ |
| 539 | new_page = old_page; |
| 540 | } |
| 541 | page_cache_release(new_page); |
| 542 | page_cache_release(old_page); |
| 543 | return VM_FAULT_MINOR; |
| 544 | } |
| 545 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 546 | int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 547 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 548 | { |
| 549 | int ret = VM_FAULT_SIGBUS; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 550 | unsigned long idx; |
| 551 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 552 | struct page *page; |
| 553 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 554 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 555 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 556 | mapping = vma->vm_file->f_mapping; |
| 557 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) |
| 558 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 559 | |
| 560 | /* |
| 561 | * Use page lock to guard against racing truncation |
| 562 | * before we get page_table_lock. |
| 563 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 564 | retry: |
| 565 | page = find_lock_page(mapping, idx); |
| 566 | if (!page) { |
| 567 | if (hugetlb_get_quota(mapping)) |
| 568 | goto out; |
| 569 | page = alloc_huge_page(vma, address); |
| 570 | if (!page) { |
| 571 | hugetlb_put_quota(mapping); |
Christoph Lameter | 0df420d | 2006-02-07 12:58:30 -0800 | [diff] [blame] | 572 | ret = VM_FAULT_OOM; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 573 | goto out; |
| 574 | } |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 575 | clear_huge_page(page, address); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 576 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 577 | if (vma->vm_flags & VM_SHARED) { |
| 578 | int err; |
| 579 | |
| 580 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 581 | if (err) { |
| 582 | put_page(page); |
| 583 | hugetlb_put_quota(mapping); |
| 584 | if (err == -EEXIST) |
| 585 | goto retry; |
| 586 | goto out; |
| 587 | } |
| 588 | } else |
| 589 | lock_page(page); |
| 590 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 591 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 592 | spin_lock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 593 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 594 | if (idx >= size) |
| 595 | goto backout; |
| 596 | |
| 597 | ret = VM_FAULT_MINOR; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 598 | if (!pte_none(*ptep)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 599 | goto backout; |
| 600 | |
| 601 | add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 602 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 603 | && (vma->vm_flags & VM_SHARED))); |
| 604 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 605 | |
| 606 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 607 | /* Optimization, do the COW without a second fault */ |
| 608 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); |
| 609 | } |
| 610 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 611 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 612 | unlock_page(page); |
| 613 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 614 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 615 | |
| 616 | backout: |
| 617 | spin_unlock(&mm->page_table_lock); |
| 618 | hugetlb_put_quota(mapping); |
| 619 | unlock_page(page); |
| 620 | put_page(page); |
| 621 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 622 | } |
| 623 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 624 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 625 | unsigned long address, int write_access) |
| 626 | { |
| 627 | pte_t *ptep; |
| 628 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 629 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 630 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 631 | |
| 632 | ptep = huge_pte_alloc(mm, address); |
| 633 | if (!ptep) |
| 634 | return VM_FAULT_OOM; |
| 635 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 636 | /* |
| 637 | * Serialize hugepage allocation and instantiation, so that we don't |
| 638 | * get spurious allocation failures if two CPUs race to instantiate |
| 639 | * the same page in the page cache. |
| 640 | */ |
| 641 | mutex_lock(&hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 642 | entry = *ptep; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 643 | if (pte_none(entry)) { |
| 644 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 645 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 646 | return ret; |
| 647 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 648 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 649 | ret = VM_FAULT_MINOR; |
| 650 | |
| 651 | spin_lock(&mm->page_table_lock); |
| 652 | /* Check for a racing update before calling hugetlb_cow */ |
| 653 | if (likely(pte_same(entry, *ptep))) |
| 654 | if (write_access && !pte_write(entry)) |
| 655 | ret = hugetlb_cow(mm, vma, address, ptep, entry); |
| 656 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 657 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 658 | |
| 659 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 660 | } |
| 661 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 662 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 663 | struct page **pages, struct vm_area_struct **vmas, |
| 664 | unsigned long *position, int *length, int i) |
| 665 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 666 | unsigned long pfn_offset; |
| 667 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 668 | int remainder = *length; |
| 669 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 670 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 671 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 672 | pte_t *pte; |
| 673 | struct page *page; |
| 674 | |
| 675 | /* |
| 676 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 677 | * each hugepage. We have to make * sure we get the |
| 678 | * first, for the page indexing below to work. |
| 679 | */ |
| 680 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); |
| 681 | |
| 682 | if (!pte || pte_none(*pte)) { |
| 683 | int ret; |
| 684 | |
| 685 | spin_unlock(&mm->page_table_lock); |
| 686 | ret = hugetlb_fault(mm, vma, vaddr, 0); |
| 687 | spin_lock(&mm->page_table_lock); |
| 688 | if (ret == VM_FAULT_MINOR) |
| 689 | continue; |
| 690 | |
| 691 | remainder = 0; |
| 692 | if (!i) |
| 693 | i = -EFAULT; |
| 694 | break; |
| 695 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 696 | |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 697 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
| 698 | page = pte_page(*pte); |
| 699 | same_page: |
| 700 | get_page(page); |
| 701 | if (pages) |
| 702 | pages[i] = page + pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 703 | |
| 704 | if (vmas) |
| 705 | vmas[i] = vma; |
| 706 | |
| 707 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 708 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 709 | --remainder; |
| 710 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 711 | if (vaddr < vma->vm_end && remainder && |
| 712 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { |
| 713 | /* |
| 714 | * We use pfn_offset to avoid touching the pageframes |
| 715 | * of this compound page. |
| 716 | */ |
| 717 | goto same_page; |
| 718 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 719 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 720 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 721 | *length = remainder; |
| 722 | *position = vaddr; |
| 723 | |
| 724 | return i; |
| 725 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 726 | |
| 727 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 728 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 729 | { |
| 730 | struct mm_struct *mm = vma->vm_mm; |
| 731 | unsigned long start = address; |
| 732 | pte_t *ptep; |
| 733 | pte_t pte; |
| 734 | |
| 735 | BUG_ON(address >= end); |
| 736 | flush_cache_range(vma, address, end); |
| 737 | |
| 738 | spin_lock(&mm->page_table_lock); |
| 739 | for (; address < end; address += HPAGE_SIZE) { |
| 740 | ptep = huge_pte_offset(mm, address); |
| 741 | if (!ptep) |
| 742 | continue; |
| 743 | if (!pte_none(*ptep)) { |
| 744 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 745 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 746 | set_huge_pte_at(mm, address, ptep, pte); |
| 747 | lazy_mmu_prot_update(pte); |
| 748 | } |
| 749 | } |
| 750 | spin_unlock(&mm->page_table_lock); |
| 751 | |
| 752 | flush_tlb_range(vma, start, end); |
| 753 | } |
| 754 | |