1 #ifndef _LINUX_MM_TYPES_H
2 #define _LINUX_MM_TYPES_H
3
4 #include <linux/auxvec.h>
5 #include <linux/types.h>
6 #include <linux/threads.h>
7 #include <linux/list.h>
8 #include <linux/spinlock.h>
9 #include <linux/prio_tree.h>
10 #include <linux/rbtree.h>
11 #include <linux/rwsem.h>
12 #include <linux/completion.h>
13 #include <linux/cpumask.h>
14 #include <linux/page-debug-flags.h>
15 #include <asm/page.h>
16 #include <asm/mmu.h>
17
18 #ifndef AT_VECTOR_SIZE_ARCH
19 #define AT_VECTOR_SIZE_ARCH 0
20 #endif
21 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
22
23 struct address_space;
24
25 #define USE_SPLIT_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
26
27 /*
28 * Each physical page in the system has a struct page associated with
29 * it to keep track of whatever it is we are using the page for at the
30 * moment. Note that we have no way to track which tasks are using
31 * a page, though if it is a pagecache page, rmap structures can tell us
32 * who is mapping it.
33 *
34 * The objects in struct page are organized in double word blocks in
35 * order to allows us to use atomic double word operations on portions
36 * of struct page. That is currently only used by slub but the arrangement
37 * allows the use of atomic double word operations on the flags/mapping
38 * and lru list pointers also.
39 */
40 struct page {
41 /* First double word block */
42 unsigned long flags; /* Atomic flags, some possibly
43 * updated asynchronously */
44 struct address_space *mapping; /* If low bit clear, points to
45 * inode address_space, or NULL.
46 * If page mapped as anonymous
47 * memory, low bit is set, and
48 * it points to anon_vma object:
49 * see PAGE_MAPPING_ANON below.
50 */
51 /* Second double word */
52 struct {
53 union {
54 pgoff_t index; /* Our offset within mapping. */
55 void *freelist; /* slub first free object */
56 };
57
58 union {
59 /* Used for cmpxchg_double in slub */
60 unsigned long counters;
61
62 struct {
63
64 union {
65 /*
66 * Count of ptes mapped in
67 * mms, to show when page is
68 * mapped & limit reverse map
69 * searches.
70 *
71 * Used also for tail pages
72 * refcounting instead of
73 * _count. Tail pages cannot
74 * be mapped and keeping the
75 * tail page _count zero at
76 * all times guarantees
77 * get_page_unless_zero() will
78 * never succeed on tail
79 * pages.
80 */
81 atomic_t _mapcount;
82
83 struct {
84 unsigned inuse:16;
85 unsigned objects:15;
86 unsigned frozen:1;
87 };
88 };
89 atomic_t _count; /* Usage count, see below. */
90 };
91 };
92 };
93
94 /* Third double word block */
95 union {
96 struct list_head lru; /* Pageout list, eg. active_list
97 * protected by zone->lru_lock !
98 */
99 struct { /* slub per cpu partial pages */
100 struct page *next; /* Next partial slab */
101 #ifdef CONFIG_64BIT
102 int pages; /* Nr of partial slabs left */
103 int pobjects; /* Approximate # of objects */
104 #else
105 short int pages;
106 short int pobjects;
107 #endif
108 };
109 };
110
111 /* Remainder is not double word aligned */
112 union {
113 unsigned long private; /* Mapping-private opaque data:
114 * usually used for buffer_heads
115 * if PagePrivate set; used for
116 * swp_entry_t if PageSwapCache;
117 * indicates order in the buddy
118 * system if PG_buddy is set.
119 */
120 #if USE_SPLIT_PTLOCKS
121 spinlock_t ptl;
122 #endif
123 struct kmem_cache *slab; /* SLUB: Pointer to slab */
124 struct page *first_page; /* Compound tail pages */
125 };
126
127 /*
128 * On machines where all RAM is mapped into kernel address space,
129 * we can simply calculate the virtual address. On machines with
130 * highmem some memory is mapped into kernel virtual memory
131 * dynamically, so we need a place to store that address.
132 * Note that this field could be 16 bits on x86 ... ;)
133 *
134 * Architectures with slow multiplication can define
135 * WANT_PAGE_VIRTUAL in asm/page.h
136 */
137 #if defined(WANT_PAGE_VIRTUAL)
138 void *virtual; /* Kernel virtual address (NULL if
139 not kmapped, ie. highmem) */
140 #endif /* WANT_PAGE_VIRTUAL */
141 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
142 unsigned long debug_flags; /* Use atomic bitops on this */
143 #endif
144
145 #ifdef CONFIG_KMEMCHECK
146 /*
147 * kmemcheck wants to track the status of each byte in a page; this
148 * is a pointer to such a status block. NULL if not tracked.
149 */
150 void *shadow;
151 #endif
152 }
153 /*
154 * The struct page can be forced to be double word aligned so that atomic ops
155 * on double words work. The SLUB allocator can make use of such a feature.
156 */
157 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
158 __aligned(2 * sizeof(unsigned long))
159 #endif
160 ;
161
162 struct page_frag {
163 struct page *page;
164 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
165 __u32 offset;
166 __u32 size;
167 #else
168 __u16 offset;
169 __u16 size;
170 #endif
171 };
172
173 typedef unsigned long __nocast vm_flags_t;
174
175 /*
176 * A region containing a mapping of a non-memory backed file under NOMMU
177 * conditions. These are held in a global tree and are pinned by the VMAs that
178 * map parts of them.
179 */
180 struct vm_region {
181 struct rb_node vm_rb; /* link in global region tree */
182 vm_flags_t vm_flags; /* VMA vm_flags */
183 unsigned long vm_start; /* start address of region */
184 unsigned long vm_end; /* region initialised to here */
185 unsigned long vm_top; /* region allocated to here */
186 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
187 struct file *vm_file; /* the backing file or NULL */
188
189 int vm_usage; /* region usage count (access under nommu_region_sem) */
190 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
191 * this region */
192 };
193
194 /*
195 * This struct defines a memory VMM memory area. There is one of these
196 * per VM-area/task. A VM area is any part of the process virtual memory
197 * space that has a special rule for the page-fault handlers (ie a shared
198 * library, the executable area etc).
199 */
200 struct vm_area_struct {
201 struct mm_struct * vm_mm; /* The address space we belong to. */
202 unsigned long vm_start; /* Our start address within vm_mm. */
203 unsigned long vm_end; /* The first byte after our end address
204 within vm_mm. */
205
206 /* linked list of VM areas per task, sorted by address */
207 struct vm_area_struct *vm_next, *vm_prev;
208
209 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
210 unsigned long vm_flags; /* Flags, see mm.h. */
211
212 struct rb_node vm_rb;
213
214 /*
215 * For areas with an address space and backing store,
216 * linkage into the address_space->i_mmap prio tree, or
217 * linkage to the list of like vmas hanging off its node, or
218 * linkage of vma in the address_space->i_mmap_nonlinear list.
219 */
220 union {
221 struct {
222 struct list_head list;
223 void *parent; /* aligns with prio_tree_node parent */
224 struct vm_area_struct *head;
225 } vm_set;
226
227 struct raw_prio_tree_node prio_tree_node;
228 } shared;
229
230 /*
231 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
232 * list, after a COW of one of the file pages. A MAP_SHARED vma
233 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
234 * or brk vma (with NULL file) can only be in an anon_vma list.
235 */
236 struct list_head anon_vma_chain; /* Serialized by mmap_sem &
237 * page_table_lock */
238 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
239
240 /* Function pointers to deal with this struct. */
241 const struct vm_operations_struct *vm_ops;
242
243 /* Information about our backing store: */
244 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
245 units, *not* PAGE_CACHE_SIZE */
246 struct file * vm_file; /* File we map to (can be NULL). */
247 void * vm_private_data; /* was vm_pte (shared mem) */
248
249 #ifndef CONFIG_MMU
250 struct vm_region *vm_region; /* NOMMU mapping region */
251 #endif
252 #ifdef CONFIG_NUMA
253 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
254 #endif
255 };
256
257 struct core_thread {
258 struct task_struct *task;
259 struct core_thread *next;
260 };
261
262 struct core_state {
263 atomic_t nr_threads;
264 struct core_thread dumper;
265 struct completion startup;
266 };
267
268 enum {
269 MM_FILEPAGES,
270 MM_ANONPAGES,
271 MM_SWAPENTS,
272 NR_MM_COUNTERS
273 };
274
275 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)
276 #define SPLIT_RSS_COUNTING
277 /* per-thread cached information, */
278 struct task_rss_stat {
279 int events; /* for synchronization threshold */
280 int count[NR_MM_COUNTERS];
281 };
282 #endif /* USE_SPLIT_PTLOCKS */
283
284 struct mm_rss_stat {
285 atomic_long_t count[NR_MM_COUNTERS];
286 };
287
288 struct mm_struct {
289 struct vm_area_struct * mmap; /* list of VMAs */
290 struct rb_root mm_rb;
291 struct vm_area_struct * mmap_cache; /* last find_vma result */
292 #ifdef CONFIG_MMU
293 unsigned long (*get_unmapped_area) (struct file *filp,
294 unsigned long addr, unsigned long len,
295 unsigned long pgoff, unsigned long flags);
296 void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
297 #endif
298 unsigned long mmap_base; /* base of mmap area */
299 unsigned long task_size; /* size of task vm space */
300 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */
301 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */
302 pgd_t * pgd;
303 atomic_t mm_users; /* How many users with user space? */
304 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
305 int map_count; /* number of VMAs */
306
307 spinlock_t page_table_lock; /* Protects page tables and some counters */
308 struct rw_semaphore mmap_sem;
309
310 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
311 * together off init_mm.mmlist, and are protected
312 * by mmlist_lock
313 */
314
315
316 unsigned long hiwater_rss; /* High-watermark of RSS usage */
317 unsigned long hiwater_vm; /* High-water virtual memory usage */
318
319 unsigned long total_vm; /* Total pages mapped */
320 unsigned long locked_vm; /* Pages that have PG_mlocked set */
321 unsigned long pinned_vm; /* Refcount permanently increased */
322 unsigned long shared_vm; /* Shared pages (files) */
323 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */
324 unsigned long stack_vm; /* VM_GROWSUP/DOWN */
325 unsigned long reserved_vm; /* VM_RESERVED|VM_IO pages */
326 unsigned long def_flags;
327 unsigned long nr_ptes; /* Page table pages */
328 unsigned long start_code, end_code, start_data, end_data;
329 unsigned long start_brk, brk, start_stack;
330 unsigned long arg_start, arg_end, env_start, env_end;
331
332 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
333
334 /*
335 * Special counters, in some configurations protected by the
336 * page_table_lock, in other configurations by being atomic.
337 */
338 struct mm_rss_stat rss_stat;
339
340 struct linux_binfmt *binfmt;
341
342 cpumask_var_t cpu_vm_mask_var;
343
344 /* Architecture-specific MM context */
345 mm_context_t context;
346
347 /* Swap token stuff */
348 /*
349 * Last value of global fault stamp as seen by this process.
350 * In other words, this value gives an indication of how long
351 * it has been since this task got the token.
352 * Look at mm/thrash.c
353 */
354 unsigned int faultstamp;
355 unsigned int token_priority;
356 unsigned int last_interval;
357
358 unsigned long flags; /* Must use atomic bitops to access the bits */
359
360 struct core_state *core_state; /* coredumping support */
361 #ifdef CONFIG_AIO
362 spinlock_t ioctx_lock;
363 struct hlist_head ioctx_list;
364 #endif
365 #ifdef CONFIG_MM_OWNER
366 /*
367 * "owner" points to a task that is regarded as the canonical
368 * user/owner of this mm. All of the following must be true in
369 * order for it to be changed:
370 *
371 * current == mm->owner
372 * current->mm != mm
373 * new_owner->mm == mm
374 * new_owner->alloc_lock is held
375 */
376 struct task_struct __rcu *owner;
377 #endif
378
379 /* store ref to file /proc/<pid>/exe symlink points to */
380 struct file *exe_file;
381 unsigned long num_exe_file_vmas;
382 #ifdef CONFIG_MMU_NOTIFIER
383 struct mmu_notifier_mm *mmu_notifier_mm;
384 #endif
385 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
386 pgtable_t pmd_huge_pte; /* protected by page_table_lock */
387 #endif
388 #ifdef CONFIG_CPUMASK_OFFSTACK
389 struct cpumask cpumask_allocation;
390 #endif
391 };
392
mm_init_cpumask(struct mm_struct * mm)393 static inline void mm_init_cpumask(struct mm_struct *mm)
394 {
395 #ifdef CONFIG_CPUMASK_OFFSTACK
396 mm->cpu_vm_mask_var = &mm->cpumask_allocation;
397 #endif
398 }
399
400 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
mm_cpumask(struct mm_struct * mm)401 static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
402 {
403 return mm->cpu_vm_mask_var;
404 }
405
406 #endif /* _LINUX_MM_TYPES_H */
407