1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_MM_TYPES_H |
3 | #define _LINUX_MM_TYPES_H |
4 | |
5 | #include <linux/mm_types_task.h> |
6 | |
7 | #include <linux/auxvec.h> |
8 | #include <linux/list.h> |
9 | #include <linux/spinlock.h> |
10 | #include <linux/rbtree.h> |
11 | #include <linux/rwsem.h> |
12 | #include <linux/completion.h> |
13 | #include <linux/cpumask.h> |
14 | #include <linux/uprobes.h> |
15 | #include <linux/page-flags-layout.h> |
16 | #include <linux/workqueue.h> |
17 | |
18 | #include <asm/mmu.h> |
19 | |
20 | #ifndef AT_VECTOR_SIZE_ARCH |
21 | #define AT_VECTOR_SIZE_ARCH 0 |
22 | #endif |
23 | #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) |
24 | |
25 | |
26 | struct address_space; |
27 | struct mem_cgroup; |
28 | struct hmm; |
29 | |
30 | /* |
31 | * Each physical page in the system has a struct page associated with |
32 | * it to keep track of whatever it is we are using the page for at the |
33 | * moment. Note that we have no way to track which tasks are using |
34 | * a page, though if it is a pagecache page, rmap structures can tell us |
35 | * who is mapping it. |
36 | * |
37 | * If you allocate the page using alloc_pages(), you can use some of the |
38 | * space in struct page for your own purposes. The five words in the main |
39 | * union are available, except for bit 0 of the first word which must be |
40 | * kept clear. Many users use this word to store a pointer to an object |
41 | * which is guaranteed to be aligned. If you use the same storage as |
42 | * page->mapping, you must restore it to NULL before freeing the page. |
43 | * |
44 | * If your page will not be mapped to userspace, you can also use the four |
45 | * bytes in the mapcount union, but you must call page_mapcount_reset() |
46 | * before freeing it. |
47 | * |
48 | * If you want to use the refcount field, it must be used in such a way |
49 | * that other CPUs temporarily incrementing and then decrementing the |
50 | * refcount does not cause problems. On receiving the page from |
51 | * alloc_pages(), the refcount will be positive. |
52 | * |
53 | * If you allocate pages of order > 0, you can use some of the fields |
54 | * in each subpage, but you may need to restore some of their values |
55 | * afterwards. |
56 | * |
57 | * SLUB uses cmpxchg_double() to atomically update its freelist and |
58 | * counters. That requires that freelist & counters be adjacent and |
59 | * double-word aligned. We align all struct pages to double-word |
60 | * boundaries, and ensure that 'freelist' is aligned within the |
61 | * struct. |
62 | */ |
63 | #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE |
64 | #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) |
65 | #else |
66 | #define _struct_page_alignment |
67 | #endif |
68 | |
69 | struct page { |
70 | unsigned long flags; /* Atomic flags, some possibly |
71 | * updated asynchronously */ |
72 | /* |
73 | * Five words (20/40 bytes) are available in this union. |
74 | * WARNING: bit 0 of the first word is used for PageTail(). That |
75 | * means the other users of this union MUST NOT use the bit to |
76 | * avoid collision and false-positive PageTail(). |
77 | */ |
78 | union { |
79 | struct { /* Page cache and anonymous pages */ |
80 | /** |
81 | * @lru: Pageout list, eg. active_list protected by |
82 | * pgdat->lru_lock. Sometimes used as a generic list |
83 | * by the page owner. |
84 | */ |
85 | struct list_head lru; |
86 | /* See page-flags.h for PAGE_MAPPING_FLAGS */ |
87 | struct address_space *mapping; |
88 | pgoff_t index; /* Our offset within mapping. */ |
89 | /** |
90 | * @private: Mapping-private opaque data. |
91 | * Usually used for buffer_heads if PagePrivate. |
92 | * Used for swp_entry_t if PageSwapCache. |
93 | * Indicates order in the buddy system if PageBuddy. |
94 | */ |
95 | unsigned long private; |
96 | }; |
97 | struct { /* page_pool used by netstack */ |
98 | /** |
99 | * @dma_addr: might require a 64-bit value even on |
100 | * 32-bit architectures. |
101 | */ |
102 | dma_addr_t dma_addr; |
103 | }; |
104 | struct { /* slab, slob and slub */ |
105 | union { |
106 | struct list_head slab_list; /* uses lru */ |
107 | struct { /* Partial pages */ |
108 | struct page *next; |
109 | #ifdef CONFIG_64BIT |
110 | int pages; /* Nr of pages left */ |
111 | int pobjects; /* Approximate count */ |
112 | #else |
113 | short int pages; |
114 | short int pobjects; |
115 | #endif |
116 | }; |
117 | }; |
118 | struct kmem_cache *slab_cache; /* not slob */ |
119 | /* Double-word boundary */ |
120 | void *freelist; /* first free object */ |
121 | union { |
122 | void *s_mem; /* slab: first object */ |
123 | unsigned long counters; /* SLUB */ |
124 | struct { /* SLUB */ |
125 | unsigned inuse:16; |
126 | unsigned objects:15; |
127 | unsigned frozen:1; |
128 | }; |
129 | }; |
130 | }; |
131 | struct { /* Tail pages of compound page */ |
132 | unsigned long compound_head; /* Bit zero is set */ |
133 | |
134 | /* First tail page only */ |
135 | unsigned char compound_dtor; |
136 | unsigned char compound_order; |
137 | atomic_t compound_mapcount; |
138 | }; |
139 | struct { /* Second tail page of compound page */ |
140 | unsigned long _compound_pad_1; /* compound_head */ |
141 | unsigned long _compound_pad_2; |
142 | struct list_head deferred_list; |
143 | }; |
144 | struct { /* Page table pages */ |
145 | unsigned long _pt_pad_1; /* compound_head */ |
146 | pgtable_t pmd_huge_pte; /* protected by page->ptl */ |
147 | unsigned long _pt_pad_2; /* mapping */ |
148 | union { |
149 | struct mm_struct *pt_mm; /* x86 pgds only */ |
150 | atomic_t pt_frag_refcount; /* powerpc */ |
151 | }; |
152 | #if ALLOC_SPLIT_PTLOCKS |
153 | spinlock_t *ptl; |
154 | #else |
155 | spinlock_t ptl; |
156 | #endif |
157 | }; |
158 | struct { /* ZONE_DEVICE pages */ |
159 | /** @pgmap: Points to the hosting device page map. */ |
160 | struct dev_pagemap *pgmap; |
161 | unsigned long hmm_data; |
162 | unsigned long _zd_pad_1; /* uses mapping */ |
163 | }; |
164 | |
165 | /** @rcu_head: You can use this to free a page by RCU. */ |
166 | struct rcu_head rcu_head; |
167 | }; |
168 | |
169 | union { /* This union is 4 bytes in size. */ |
170 | /* |
171 | * If the page can be mapped to userspace, encodes the number |
172 | * of times this page is referenced by a page table. |
173 | */ |
174 | atomic_t _mapcount; |
175 | |
176 | /* |
177 | * If the page is neither PageSlab nor mappable to userspace, |
178 | * the value stored here may help determine what this page |
179 | * is used for. See page-flags.h for a list of page types |
180 | * which are currently stored here. |
181 | */ |
182 | unsigned int page_type; |
183 | |
184 | unsigned int active; /* SLAB */ |
185 | int units; /* SLOB */ |
186 | }; |
187 | |
188 | /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ |
189 | atomic_t _refcount; |
190 | |
191 | #ifdef CONFIG_MEMCG |
192 | struct mem_cgroup *mem_cgroup; |
193 | #endif |
194 | |
195 | /* |
196 | * On machines where all RAM is mapped into kernel address space, |
197 | * we can simply calculate the virtual address. On machines with |
198 | * highmem some memory is mapped into kernel virtual memory |
199 | * dynamically, so we need a place to store that address. |
200 | * Note that this field could be 16 bits on x86 ... ;) |
201 | * |
202 | * Architectures with slow multiplication can define |
203 | * WANT_PAGE_VIRTUAL in asm/page.h |
204 | */ |
205 | #if defined(WANT_PAGE_VIRTUAL) |
206 | void *virtual; /* Kernel virtual address (NULL if |
207 | not kmapped, ie. highmem) */ |
208 | #endif /* WANT_PAGE_VIRTUAL */ |
209 | |
210 | #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS |
211 | int _last_cpupid; |
212 | #endif |
213 | } _struct_page_alignment; |
214 | |
215 | /* |
216 | * Used for sizing the vmemmap region on some architectures |
217 | */ |
218 | #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) |
219 | |
220 | #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) |
221 | #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) |
222 | |
223 | struct page_frag_cache { |
224 | void * va; |
225 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) |
226 | __u16 offset; |
227 | __u16 size; |
228 | #else |
229 | __u32 offset; |
230 | #endif |
231 | /* we maintain a pagecount bias, so that we dont dirty cache line |
232 | * containing page->_refcount every time we allocate a fragment. |
233 | */ |
234 | unsigned int pagecnt_bias; |
235 | bool pfmemalloc; |
236 | }; |
237 | |
238 | typedef unsigned long vm_flags_t; |
239 | |
240 | /* |
241 | * A region containing a mapping of a non-memory backed file under NOMMU |
242 | * conditions. These are held in a global tree and are pinned by the VMAs that |
243 | * map parts of them. |
244 | */ |
245 | struct vm_region { |
246 | struct rb_node vm_rb; /* link in global region tree */ |
247 | vm_flags_t vm_flags; /* VMA vm_flags */ |
248 | unsigned long vm_start; /* start address of region */ |
249 | unsigned long vm_end; /* region initialised to here */ |
250 | unsigned long vm_top; /* region allocated to here */ |
251 | unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ |
252 | struct file *vm_file; /* the backing file or NULL */ |
253 | |
254 | int vm_usage; /* region usage count (access under nommu_region_sem) */ |
255 | bool vm_icache_flushed : 1; /* true if the icache has been flushed for |
256 | * this region */ |
257 | }; |
258 | |
259 | #ifdef CONFIG_USERFAULTFD |
260 | #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) |
261 | struct vm_userfaultfd_ctx { |
262 | struct userfaultfd_ctx *ctx; |
263 | }; |
264 | #else /* CONFIG_USERFAULTFD */ |
265 | #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) |
266 | struct vm_userfaultfd_ctx {}; |
267 | #endif /* CONFIG_USERFAULTFD */ |
268 | |
269 | /* |
270 | * This struct defines a memory VMM memory area. There is one of these |
271 | * per VM-area/task. A VM area is any part of the process virtual memory |
272 | * space that has a special rule for the page-fault handlers (ie a shared |
273 | * library, the executable area etc). |
274 | */ |
275 | struct vm_area_struct { |
276 | /* The first cache line has the info for VMA tree walking. */ |
277 | |
278 | unsigned long vm_start; /* Our start address within vm_mm. */ |
279 | unsigned long vm_end; /* The first byte after our end address |
280 | within vm_mm. */ |
281 | |
282 | /* linked list of VM areas per task, sorted by address */ |
283 | struct vm_area_struct *vm_next, *vm_prev; |
284 | |
285 | struct rb_node vm_rb; |
286 | |
287 | /* |
288 | * Largest free memory gap in bytes to the left of this VMA. |
289 | * Either between this VMA and vma->vm_prev, or between one of the |
290 | * VMAs below us in the VMA rbtree and its ->vm_prev. This helps |
291 | * get_unmapped_area find a free area of the right size. |
292 | */ |
293 | unsigned long rb_subtree_gap; |
294 | |
295 | /* Second cache line starts here. */ |
296 | |
297 | struct mm_struct *vm_mm; /* The address space we belong to. */ |
298 | pgprot_t vm_page_prot; /* Access permissions of this VMA. */ |
299 | unsigned long vm_flags; /* Flags, see mm.h. */ |
300 | |
301 | /* |
302 | * For areas with an address space and backing store, |
303 | * linkage into the address_space->i_mmap interval tree. |
304 | */ |
305 | struct { |
306 | struct rb_node rb; |
307 | unsigned long rb_subtree_last; |
308 | } shared; |
309 | |
310 | /* |
311 | * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma |
312 | * list, after a COW of one of the file pages. A MAP_SHARED vma |
313 | * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack |
314 | * or brk vma (with NULL file) can only be in an anon_vma list. |
315 | */ |
316 | struct list_head anon_vma_chain; /* Serialized by mmap_sem & |
317 | * page_table_lock */ |
318 | struct anon_vma *anon_vma; /* Serialized by page_table_lock */ |
319 | |
320 | /* Function pointers to deal with this struct. */ |
321 | const struct vm_operations_struct *vm_ops; |
322 | |
323 | /* Information about our backing store: */ |
324 | unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE |
325 | units */ |
326 | struct file * vm_file; /* File we map to (can be NULL). */ |
327 | void * vm_private_data; /* was vm_pte (shared mem) */ |
328 | |
329 | atomic_long_t swap_readahead_info; |
330 | #ifndef CONFIG_MMU |
331 | struct vm_region *vm_region; /* NOMMU mapping region */ |
332 | #endif |
333 | #ifdef CONFIG_NUMA |
334 | struct mempolicy *vm_policy; /* NUMA policy for the VMA */ |
335 | #endif |
336 | struct vm_userfaultfd_ctx vm_userfaultfd_ctx; |
337 | } __randomize_layout; |
338 | |
339 | struct core_thread { |
340 | struct task_struct *task; |
341 | struct core_thread *next; |
342 | }; |
343 | |
344 | struct core_state { |
345 | atomic_t nr_threads; |
346 | struct core_thread dumper; |
347 | struct completion startup; |
348 | }; |
349 | |
350 | struct kioctx_table; |
351 | struct mm_struct { |
352 | struct { |
353 | struct vm_area_struct *mmap; /* list of VMAs */ |
354 | struct rb_root mm_rb; |
355 | u64 vmacache_seqnum; /* per-thread vmacache */ |
356 | #ifdef CONFIG_MMU |
357 | unsigned long (*get_unmapped_area) (struct file *filp, |
358 | unsigned long addr, unsigned long len, |
359 | unsigned long pgoff, unsigned long flags); |
360 | #endif |
361 | unsigned long mmap_base; /* base of mmap area */ |
362 | unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ |
363 | #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES |
364 | /* Base adresses for compatible mmap() */ |
365 | unsigned long mmap_compat_base; |
366 | unsigned long mmap_compat_legacy_base; |
367 | #endif |
368 | unsigned long task_size; /* size of task vm space */ |
369 | unsigned long highest_vm_end; /* highest vma end address */ |
370 | pgd_t * pgd; |
371 | |
372 | /** |
373 | * @mm_users: The number of users including userspace. |
374 | * |
375 | * Use mmget()/mmget_not_zero()/mmput() to modify. When this |
376 | * drops to 0 (i.e. when the task exits and there are no other |
377 | * temporary reference holders), we also release a reference on |
378 | * @mm_count (which may then free the &struct mm_struct if |
379 | * @mm_count also drops to 0). |
380 | */ |
381 | atomic_t mm_users; |
382 | |
383 | /** |
384 | * @mm_count: The number of references to &struct mm_struct |
385 | * (@mm_users count as 1). |
386 | * |
387 | * Use mmgrab()/mmdrop() to modify. When this drops to 0, the |
388 | * &struct mm_struct is freed. |
389 | */ |
390 | atomic_t mm_count; |
391 | |
392 | #ifdef CONFIG_MMU |
393 | atomic_long_t pgtables_bytes; /* PTE page table pages */ |
394 | #endif |
395 | int map_count; /* number of VMAs */ |
396 | |
397 | spinlock_t page_table_lock; /* Protects page tables and some |
398 | * counters |
399 | */ |
400 | struct rw_semaphore mmap_sem; |
401 | |
402 | struct list_head mmlist; /* List of maybe swapped mm's. These |
403 | * are globally strung together off |
404 | * init_mm.mmlist, and are protected |
405 | * by mmlist_lock |
406 | */ |
407 | |
408 | |
409 | unsigned long ; /* High-watermark of RSS usage */ |
410 | unsigned long hiwater_vm; /* High-water virtual memory usage */ |
411 | |
412 | unsigned long total_vm; /* Total pages mapped */ |
413 | unsigned long locked_vm; /* Pages that have PG_mlocked set */ |
414 | atomic64_t pinned_vm; /* Refcount permanently increased */ |
415 | unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ |
416 | unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ |
417 | unsigned long stack_vm; /* VM_STACK */ |
418 | unsigned long def_flags; |
419 | |
420 | spinlock_t arg_lock; /* protect the below fields */ |
421 | unsigned long start_code, end_code, start_data, end_data; |
422 | unsigned long start_brk, brk, start_stack; |
423 | unsigned long arg_start, arg_end, env_start, env_end; |
424 | |
425 | unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ |
426 | |
427 | /* |
428 | * Special counters, in some configurations protected by the |
429 | * page_table_lock, in other configurations by being atomic. |
430 | */ |
431 | struct mm_rss_stat ; |
432 | |
433 | struct linux_binfmt *binfmt; |
434 | |
435 | /* Architecture-specific MM context */ |
436 | mm_context_t context; |
437 | |
438 | unsigned long flags; /* Must use atomic bitops to access */ |
439 | |
440 | struct core_state *core_state; /* coredumping support */ |
441 | #ifdef CONFIG_MEMBARRIER |
442 | atomic_t membarrier_state; |
443 | #endif |
444 | #ifdef CONFIG_AIO |
445 | spinlock_t ioctx_lock; |
446 | struct kioctx_table __rcu *ioctx_table; |
447 | #endif |
448 | #ifdef CONFIG_MEMCG |
449 | /* |
450 | * "owner" points to a task that is regarded as the canonical |
451 | * user/owner of this mm. All of the following must be true in |
452 | * order for it to be changed: |
453 | * |
454 | * current == mm->owner |
455 | * current->mm != mm |
456 | * new_owner->mm == mm |
457 | * new_owner->alloc_lock is held |
458 | */ |
459 | struct task_struct __rcu *owner; |
460 | #endif |
461 | struct user_namespace *user_ns; |
462 | |
463 | /* store ref to file /proc/<pid>/exe symlink points to */ |
464 | struct file __rcu *exe_file; |
465 | #ifdef CONFIG_MMU_NOTIFIER |
466 | struct mmu_notifier_mm *mmu_notifier_mm; |
467 | #endif |
468 | #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS |
469 | pgtable_t pmd_huge_pte; /* protected by page_table_lock */ |
470 | #endif |
471 | #ifdef CONFIG_NUMA_BALANCING |
472 | /* |
473 | * numa_next_scan is the next time that the PTEs will be marked |
474 | * pte_numa. NUMA hinting faults will gather statistics and |
475 | * migrate pages to new nodes if necessary. |
476 | */ |
477 | unsigned long numa_next_scan; |
478 | |
479 | /* Restart point for scanning and setting pte_numa */ |
480 | unsigned long numa_scan_offset; |
481 | |
482 | /* numa_scan_seq prevents two threads setting pte_numa */ |
483 | int numa_scan_seq; |
484 | #endif |
485 | /* |
486 | * An operation with batched TLB flushing is going on. Anything |
487 | * that can move process memory needs to flush the TLB when |
488 | * moving a PROT_NONE or PROT_NUMA mapped page. |
489 | */ |
490 | atomic_t tlb_flush_pending; |
491 | #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
492 | /* See flush_tlb_batched_pending() */ |
493 | bool tlb_flush_batched; |
494 | #endif |
495 | struct uprobes_state uprobes_state; |
496 | #ifdef CONFIG_HUGETLB_PAGE |
497 | atomic_long_t hugetlb_usage; |
498 | #endif |
499 | struct work_struct async_put_work; |
500 | |
501 | #if IS_ENABLED(CONFIG_HMM) |
502 | /* HMM needs to track a few things per mm */ |
503 | struct hmm *hmm; |
504 | #endif |
505 | } __randomize_layout; |
506 | |
507 | /* |
508 | * The mm_cpumask needs to be at the end of mm_struct, because it |
509 | * is dynamically sized based on nr_cpu_ids. |
510 | */ |
511 | unsigned long cpu_bitmap[]; |
512 | }; |
513 | |
514 | extern struct mm_struct init_mm; |
515 | |
516 | /* Pointer magic because the dynamic array size confuses some compilers. */ |
517 | static inline void mm_init_cpumask(struct mm_struct *mm) |
518 | { |
519 | unsigned long cpu_bitmap = (unsigned long)mm; |
520 | |
521 | cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); |
522 | cpumask_clear((struct cpumask *)cpu_bitmap); |
523 | } |
524 | |
525 | /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ |
526 | static inline cpumask_t *mm_cpumask(struct mm_struct *mm) |
527 | { |
528 | return (struct cpumask *)&mm->cpu_bitmap; |
529 | } |
530 | |
531 | struct mmu_gather; |
532 | extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, |
533 | unsigned long start, unsigned long end); |
534 | extern void tlb_finish_mmu(struct mmu_gather *tlb, |
535 | unsigned long start, unsigned long end); |
536 | |
537 | static inline void init_tlb_flush_pending(struct mm_struct *mm) |
538 | { |
539 | atomic_set(&mm->tlb_flush_pending, 0); |
540 | } |
541 | |
542 | static inline void inc_tlb_flush_pending(struct mm_struct *mm) |
543 | { |
544 | atomic_inc(&mm->tlb_flush_pending); |
545 | /* |
546 | * The only time this value is relevant is when there are indeed pages |
547 | * to flush. And we'll only flush pages after changing them, which |
548 | * requires the PTL. |
549 | * |
550 | * So the ordering here is: |
551 | * |
552 | * atomic_inc(&mm->tlb_flush_pending); |
553 | * spin_lock(&ptl); |
554 | * ... |
555 | * set_pte_at(); |
556 | * spin_unlock(&ptl); |
557 | * |
558 | * spin_lock(&ptl) |
559 | * mm_tlb_flush_pending(); |
560 | * .... |
561 | * spin_unlock(&ptl); |
562 | * |
563 | * flush_tlb_range(); |
564 | * atomic_dec(&mm->tlb_flush_pending); |
565 | * |
566 | * Where the increment if constrained by the PTL unlock, it thus |
567 | * ensures that the increment is visible if the PTE modification is |
568 | * visible. After all, if there is no PTE modification, nobody cares |
569 | * about TLB flushes either. |
570 | * |
571 | * This very much relies on users (mm_tlb_flush_pending() and |
572 | * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and |
573 | * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc |
574 | * locks (PPC) the unlock of one doesn't order against the lock of |
575 | * another PTL. |
576 | * |
577 | * The decrement is ordered by the flush_tlb_range(), such that |
578 | * mm_tlb_flush_pending() will not return false unless all flushes have |
579 | * completed. |
580 | */ |
581 | } |
582 | |
583 | static inline void dec_tlb_flush_pending(struct mm_struct *mm) |
584 | { |
585 | /* |
586 | * See inc_tlb_flush_pending(). |
587 | * |
588 | * This cannot be smp_mb__before_atomic() because smp_mb() simply does |
589 | * not order against TLB invalidate completion, which is what we need. |
590 | * |
591 | * Therefore we must rely on tlb_flush_*() to guarantee order. |
592 | */ |
593 | atomic_dec(&mm->tlb_flush_pending); |
594 | } |
595 | |
596 | static inline bool mm_tlb_flush_pending(struct mm_struct *mm) |
597 | { |
598 | /* |
599 | * Must be called after having acquired the PTL; orders against that |
600 | * PTLs release and therefore ensures that if we observe the modified |
601 | * PTE we must also observe the increment from inc_tlb_flush_pending(). |
602 | * |
603 | * That is, it only guarantees to return true if there is a flush |
604 | * pending for _this_ PTL. |
605 | */ |
606 | return atomic_read(&mm->tlb_flush_pending); |
607 | } |
608 | |
609 | static inline bool mm_tlb_flush_nested(struct mm_struct *mm) |
610 | { |
611 | /* |
612 | * Similar to mm_tlb_flush_pending(), we must have acquired the PTL |
613 | * for which there is a TLB flush pending in order to guarantee |
614 | * we've seen both that PTE modification and the increment. |
615 | * |
616 | * (no requirement on actually still holding the PTL, that is irrelevant) |
617 | */ |
618 | return atomic_read(&mm->tlb_flush_pending) > 1; |
619 | } |
620 | |
621 | struct vm_fault; |
622 | |
623 | /** |
624 | * typedef vm_fault_t - Return type for page fault handlers. |
625 | * |
626 | * Page fault handlers return a bitmask of %VM_FAULT values. |
627 | */ |
628 | typedef __bitwise unsigned int vm_fault_t; |
629 | |
630 | /** |
631 | * enum vm_fault_reason - Page fault handlers return a bitmask of |
632 | * these values to tell the core VM what happened when handling the |
633 | * fault. Used to decide whether a process gets delivered SIGBUS or |
634 | * just gets major/minor fault counters bumped up. |
635 | * |
636 | * @VM_FAULT_OOM: Out Of Memory |
637 | * @VM_FAULT_SIGBUS: Bad access |
638 | * @VM_FAULT_MAJOR: Page read from storage |
639 | * @VM_FAULT_WRITE: Special case for get_user_pages |
640 | * @VM_FAULT_HWPOISON: Hit poisoned small page |
641 | * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded |
642 | * in upper bits |
643 | * @VM_FAULT_SIGSEGV: segmentation fault |
644 | * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page |
645 | * @VM_FAULT_LOCKED: ->fault locked the returned page |
646 | * @VM_FAULT_RETRY: ->fault blocked, must retry |
647 | * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small |
648 | * @VM_FAULT_DONE_COW: ->fault has fully handled COW |
649 | * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs |
650 | * fsync() to complete (for synchronous page faults |
651 | * in DAX) |
652 | * @VM_FAULT_HINDEX_MASK: mask HINDEX value |
653 | * |
654 | */ |
655 | enum vm_fault_reason { |
656 | VM_FAULT_OOM = (__force vm_fault_t)0x000001, |
657 | VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, |
658 | VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, |
659 | VM_FAULT_WRITE = (__force vm_fault_t)0x000008, |
660 | VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, |
661 | VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, |
662 | VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, |
663 | VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, |
664 | VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, |
665 | VM_FAULT_RETRY = (__force vm_fault_t)0x000400, |
666 | VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, |
667 | VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, |
668 | VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, |
669 | VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, |
670 | }; |
671 | |
672 | /* Encode hstate index for a hwpoisoned large page */ |
673 | #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) |
674 | #define VM_FAULT_GET_HINDEX(x) (((x) >> 16) & 0xf) |
675 | |
676 | #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ |
677 | VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ |
678 | VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) |
679 | |
680 | #define VM_FAULT_RESULT_TRACE \ |
681 | { VM_FAULT_OOM, "OOM" }, \ |
682 | { VM_FAULT_SIGBUS, "SIGBUS" }, \ |
683 | { VM_FAULT_MAJOR, "MAJOR" }, \ |
684 | { VM_FAULT_WRITE, "WRITE" }, \ |
685 | { VM_FAULT_HWPOISON, "HWPOISON" }, \ |
686 | { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ |
687 | { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ |
688 | { VM_FAULT_NOPAGE, "NOPAGE" }, \ |
689 | { VM_FAULT_LOCKED, "LOCKED" }, \ |
690 | { VM_FAULT_RETRY, "RETRY" }, \ |
691 | { VM_FAULT_FALLBACK, "FALLBACK" }, \ |
692 | { VM_FAULT_DONE_COW, "DONE_COW" }, \ |
693 | { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } |
694 | |
695 | struct vm_special_mapping { |
696 | const char *name; /* The name, e.g. "[vdso]". */ |
697 | |
698 | /* |
699 | * If .fault is not provided, this points to a |
700 | * NULL-terminated array of pages that back the special mapping. |
701 | * |
702 | * This must not be NULL unless .fault is provided. |
703 | */ |
704 | struct page **pages; |
705 | |
706 | /* |
707 | * If non-NULL, then this is called to resolve page faults |
708 | * on the special mapping. If used, .pages is not checked. |
709 | */ |
710 | vm_fault_t (*fault)(const struct vm_special_mapping *sm, |
711 | struct vm_area_struct *vma, |
712 | struct vm_fault *vmf); |
713 | |
714 | int (*mremap)(const struct vm_special_mapping *sm, |
715 | struct vm_area_struct *new_vma); |
716 | }; |
717 | |
718 | enum tlb_flush_reason { |
719 | TLB_FLUSH_ON_TASK_SWITCH, |
720 | TLB_REMOTE_SHOOTDOWN, |
721 | TLB_LOCAL_SHOOTDOWN, |
722 | TLB_LOCAL_MM_SHOOTDOWN, |
723 | TLB_REMOTE_SEND_IPI, |
724 | NR_TLB_FLUSH_REASONS, |
725 | }; |
726 | |
727 | /* |
728 | * A swap entry has to fit into a "unsigned long", as the entry is hidden |
729 | * in the "index" field of the swapper address space. |
730 | */ |
731 | typedef struct { |
732 | unsigned long val; |
733 | } swp_entry_t; |
734 | |
735 | #endif /* _LINUX_MM_TYPES_H */ |
736 | |