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
29 /*
30 * Each physical page in the system has a struct page associated with
31 * it to keep track of whatever it is we are using the page for at the
32 * moment. Note that we have no way to track which tasks are using
33 * a page, though if it is a pagecache page, rmap structures can tell us
34 * who is mapping it.
35 *
36 * If you allocate the page using alloc_pages(), you can use some of the
37 * space in struct page for your own purposes. The five words in the main
38 * union are available, except for bit 0 of the first word which must be
39 * kept clear. Many users use this word to store a pointer to an object
40 * which is guaranteed to be aligned. If you use the same storage as
41 * page->mapping, you must restore it to NULL before freeing the page.
42 *
43 * If your page will not be mapped to userspace, you can also use the four
44 * bytes in the mapcount union, but you must call page_mapcount_reset()
45 * before freeing it.
46 *
47 * If you want to use the refcount field, it must be used in such a way
48 * that other CPUs temporarily incrementing and then decrementing the
49 * refcount does not cause problems. On receiving the page from
50 * alloc_pages(), the refcount will be positive.
51 *
52 * If you allocate pages of order > 0, you can use some of the fields
53 * in each subpage, but you may need to restore some of their values
54 * afterwards.
55 *
56 * SLUB uses cmpxchg_double() to atomically update its freelist and
57 * counters. That requires that freelist & counters be adjacent and
58 * double-word aligned. We align all struct pages to double-word
59 * boundaries, and ensure that 'freelist' is aligned within the
60 * struct.
61 */
62 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
63 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long))
64 #else
65 #define _struct_page_alignment
66 #endif
67
68 struct page {
69 unsigned long flags; /* Atomic flags, some possibly
70 * updated asynchronously */
71 /*
72 * Five words (20/40 bytes) are available in this union.
73 * WARNING: bit 0 of the first word is used for PageTail(). That
74 * means the other users of this union MUST NOT use the bit to
75 * avoid collision and false-positive PageTail().
76 */
77 union {
78 struct { /* Page cache and anonymous pages */
79 /**
80 * @lru: Pageout list, eg. active_list protected by
81 * pgdat->lru_lock. Sometimes used as a generic list
82 * by the page owner.
83 */
84 struct list_head lru;
85 /* See page-flags.h for PAGE_MAPPING_FLAGS */
86 struct address_space *mapping;
87 pgoff_t index; /* Our offset within mapping. */
88 /**
89 * @private: Mapping-private opaque data.
90 * Usually used for buffer_heads if PagePrivate.
91 * Used for swp_entry_t if PageSwapCache.
92 * Indicates order in the buddy system if PageBuddy.
93 */
94 unsigned long private;
95 };
96 struct { /* page_pool used by netstack */
97 /**
98 * @dma_addr: might require a 64-bit value even on
99 * 32-bit architectures.
100 */
101 dma_addr_t dma_addr;
102 };
103 struct { /* slab, slob and slub */
104 union {
105 struct list_head slab_list;
106 struct { /* Partial pages */
107 struct page *next;
108 #ifdef CONFIG_64BIT
109 int pages; /* Nr of pages left */
110 int pobjects; /* Approximate count */
111 #else
112 short int pages;
113 short int pobjects;
114 #endif
115 };
116 };
117 struct kmem_cache *slab_cache; /* not slob */
118 /* Double-word boundary */
119 void *freelist; /* first free object */
120 union {
121 void *s_mem; /* slab: first object */
122 unsigned long counters; /* SLUB */
123 struct { /* SLUB */
124 unsigned inuse:16;
125 unsigned objects:15;
126 unsigned frozen:1;
127 };
128 };
129 };
130 struct { /* Tail pages of compound page */
131 unsigned long compound_head; /* Bit zero is set */
132
133 /* First tail page only */
134 unsigned char compound_dtor;
135 unsigned char compound_order;
136 atomic_t compound_mapcount;
137 };
138 struct { /* Second tail page of compound page */
139 unsigned long _compound_pad_1; /* compound_head */
140 unsigned long _compound_pad_2;
141 /* For both global and memcg */
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 void *zone_device_data;
162 /*
163 * ZONE_DEVICE private pages are counted as being
164 * mapped so the next 3 words hold the mapping, index,
165 * and private fields from the source anonymous or
166 * page cache page while the page is migrated to device
167 * private memory.
168 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
169 * use the mapping, index, and private fields when
170 * pmem backed DAX files are mapped.
171 */
172 };
173
174 /** @rcu_head: You can use this to free a page by RCU. */
175 struct rcu_head rcu_head;
176 };
177
178 union { /* This union is 4 bytes in size. */
179 /*
180 * If the page can be mapped to userspace, encodes the number
181 * of times this page is referenced by a page table.
182 */
183 atomic_t _mapcount;
184
185 /*
186 * If the page is neither PageSlab nor mappable to userspace,
187 * the value stored here may help determine what this page
188 * is used for. See page-flags.h for a list of page types
189 * which are currently stored here.
190 */
191 unsigned int page_type;
192
193 unsigned int active; /* SLAB */
194 int units; /* SLOB */
195 };
196
197 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */
198 atomic_t _refcount;
199
200 #ifdef CONFIG_MEMCG
201 struct mem_cgroup *mem_cgroup;
202 #endif
203
204 /*
205 * On machines where all RAM is mapped into kernel address space,
206 * we can simply calculate the virtual address. On machines with
207 * highmem some memory is mapped into kernel virtual memory
208 * dynamically, so we need a place to store that address.
209 * Note that this field could be 16 bits on x86 ... ;)
210 *
211 * Architectures with slow multiplication can define
212 * WANT_PAGE_VIRTUAL in asm/page.h
213 */
214 #if defined(WANT_PAGE_VIRTUAL)
215 void *virtual; /* Kernel virtual address (NULL if
216 not kmapped, ie. highmem) */
217 #endif /* WANT_PAGE_VIRTUAL */
218
219 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
220 int _last_cpupid;
221 #endif
222 } _struct_page_alignment;
223
compound_mapcount_ptr(struct page * page)224 static inline atomic_t *compound_mapcount_ptr(struct page *page)
225 {
226 return &page[1].compound_mapcount;
227 }
228
229 /*
230 * Used for sizing the vmemmap region on some architectures
231 */
232 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page)))
233
234 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
235 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
236
237 #define page_private(page) ((page)->private)
238 #define set_page_private(page, v) ((page)->private = (v))
239
240 struct page_frag_cache {
241 void * va;
242 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
243 __u16 offset;
244 __u16 size;
245 #else
246 __u32 offset;
247 #endif
248 /* we maintain a pagecount bias, so that we dont dirty cache line
249 * containing page->_refcount every time we allocate a fragment.
250 */
251 unsigned int pagecnt_bias;
252 bool pfmemalloc;
253 };
254
255 typedef unsigned long vm_flags_t;
256
257 /*
258 * A region containing a mapping of a non-memory backed file under NOMMU
259 * conditions. These are held in a global tree and are pinned by the VMAs that
260 * map parts of them.
261 */
262 struct vm_region {
263 struct rb_node vm_rb; /* link in global region tree */
264 vm_flags_t vm_flags; /* VMA vm_flags */
265 unsigned long vm_start; /* start address of region */
266 unsigned long vm_end; /* region initialised to here */
267 unsigned long vm_top; /* region allocated to here */
268 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
269 struct file *vm_file; /* the backing file or NULL */
270
271 int vm_usage; /* region usage count (access under nommu_region_sem) */
272 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
273 * this region */
274 };
275
276 #ifdef CONFIG_USERFAULTFD
277 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, })
278 struct vm_userfaultfd_ctx {
279 struct userfaultfd_ctx *ctx;
280 };
281 #else /* CONFIG_USERFAULTFD */
282 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {})
283 struct vm_userfaultfd_ctx {};
284 #endif /* CONFIG_USERFAULTFD */
285
286 /*
287 * This struct defines a memory VMM memory area. There is one of these
288 * per VM-area/task. A VM area is any part of the process virtual memory
289 * space that has a special rule for the page-fault handlers (ie a shared
290 * library, the executable area etc).
291 */
292 struct vm_area_struct {
293 /* The first cache line has the info for VMA tree walking. */
294
295 unsigned long vm_start; /* Our start address within vm_mm. */
296 unsigned long vm_end; /* The first byte after our end address
297 within vm_mm. */
298
299 /* linked list of VM areas per task, sorted by address */
300 struct vm_area_struct *vm_next, *vm_prev;
301
302 struct rb_node vm_rb;
303
304 /*
305 * Largest free memory gap in bytes to the left of this VMA.
306 * Either between this VMA and vma->vm_prev, or between one of the
307 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
308 * get_unmapped_area find a free area of the right size.
309 */
310 unsigned long rb_subtree_gap;
311
312 /* Second cache line starts here. */
313
314 struct mm_struct *vm_mm; /* The address space we belong to. */
315 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
316 unsigned long vm_flags; /* Flags, see mm.h. */
317
318 /*
319 * For areas with an address space and backing store,
320 * linkage into the address_space->i_mmap interval tree.
321 */
322 struct {
323 struct rb_node rb;
324 unsigned long rb_subtree_last;
325 } shared;
326
327 /*
328 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
329 * list, after a COW of one of the file pages. A MAP_SHARED vma
330 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
331 * or brk vma (with NULL file) can only be in an anon_vma list.
332 */
333 struct list_head anon_vma_chain; /* Serialized by mmap_sem &
334 * page_table_lock */
335 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
336
337 /* Function pointers to deal with this struct. */
338 const struct vm_operations_struct *vm_ops;
339
340 /* Information about our backing store: */
341 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
342 units */
343 struct file * vm_file; /* File we map to (can be NULL). */
344 void * vm_private_data; /* was vm_pte (shared mem) */
345
346 #ifdef CONFIG_SWAP
347 atomic_long_t swap_readahead_info;
348 #endif
349 #ifndef CONFIG_MMU
350 struct vm_region *vm_region; /* NOMMU mapping region */
351 #endif
352 #ifdef CONFIG_NUMA
353 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
354 #endif
355 struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
356 } __randomize_layout;
357
358 struct core_thread {
359 struct task_struct *task;
360 struct core_thread *next;
361 };
362
363 struct core_state {
364 atomic_t nr_threads;
365 struct core_thread dumper;
366 struct completion startup;
367 };
368
369 struct kioctx_table;
370 struct mm_struct {
371 struct {
372 struct vm_area_struct *mmap; /* list of VMAs */
373 struct rb_root mm_rb;
374 u64 vmacache_seqnum; /* per-thread vmacache */
375 #ifdef CONFIG_MMU
376 unsigned long (*get_unmapped_area) (struct file *filp,
377 unsigned long addr, unsigned long len,
378 unsigned long pgoff, unsigned long flags);
379 #endif
380 unsigned long mmap_base; /* base of mmap area */
381 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
382 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
383 /* Base adresses for compatible mmap() */
384 unsigned long mmap_compat_base;
385 unsigned long mmap_compat_legacy_base;
386 #endif
387 unsigned long task_size; /* size of task vm space */
388 unsigned long highest_vm_end; /* highest vma end address */
389 pgd_t * pgd;
390
391 #ifdef CONFIG_MEMBARRIER
392 /**
393 * @membarrier_state: Flags controlling membarrier behavior.
394 *
395 * This field is close to @pgd to hopefully fit in the same
396 * cache-line, which needs to be touched by switch_mm().
397 */
398 atomic_t membarrier_state;
399 #endif
400
401 /**
402 * @mm_users: The number of users including userspace.
403 *
404 * Use mmget()/mmget_not_zero()/mmput() to modify. When this
405 * drops to 0 (i.e. when the task exits and there are no other
406 * temporary reference holders), we also release a reference on
407 * @mm_count (which may then free the &struct mm_struct if
408 * @mm_count also drops to 0).
409 */
410 atomic_t mm_users;
411
412 /**
413 * @mm_count: The number of references to &struct mm_struct
414 * (@mm_users count as 1).
415 *
416 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the
417 * &struct mm_struct is freed.
418 */
419 atomic_t mm_count;
420
421 #ifdef CONFIG_MMU
422 atomic_long_t pgtables_bytes; /* PTE page table pages */
423 #endif
424 int map_count; /* number of VMAs */
425
426 spinlock_t page_table_lock; /* Protects page tables and some
427 * counters
428 */
429 struct rw_semaphore mmap_sem;
430
431 struct list_head mmlist; /* List of maybe swapped mm's. These
432 * are globally strung together off
433 * init_mm.mmlist, and are protected
434 * by mmlist_lock
435 */
436
437
438 unsigned long hiwater_rss; /* High-watermark of RSS usage */
439 unsigned long hiwater_vm; /* High-water virtual memory usage */
440
441 unsigned long total_vm; /* Total pages mapped */
442 unsigned long locked_vm; /* Pages that have PG_mlocked set */
443 atomic64_t pinned_vm; /* Refcount permanently increased */
444 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
445 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
446 unsigned long stack_vm; /* VM_STACK */
447 unsigned long def_flags;
448
449 spinlock_t arg_lock; /* protect the below fields */
450 unsigned long start_code, end_code, start_data, end_data;
451 unsigned long start_brk, brk, start_stack;
452 unsigned long arg_start, arg_end, env_start, env_end;
453
454 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
455
456 /*
457 * Special counters, in some configurations protected by the
458 * page_table_lock, in other configurations by being atomic.
459 */
460 struct mm_rss_stat rss_stat;
461
462 struct linux_binfmt *binfmt;
463
464 /* Architecture-specific MM context */
465 mm_context_t context;
466
467 unsigned long flags; /* Must use atomic bitops to access */
468
469 struct core_state *core_state; /* coredumping support */
470
471 #ifdef CONFIG_AIO
472 spinlock_t ioctx_lock;
473 struct kioctx_table __rcu *ioctx_table;
474 #endif
475 #ifdef CONFIG_MEMCG
476 /*
477 * "owner" points to a task that is regarded as the canonical
478 * user/owner of this mm. All of the following must be true in
479 * order for it to be changed:
480 *
481 * current == mm->owner
482 * current->mm != mm
483 * new_owner->mm == mm
484 * new_owner->alloc_lock is held
485 */
486 struct task_struct __rcu *owner;
487 #endif
488 struct user_namespace *user_ns;
489
490 /* store ref to file /proc/<pid>/exe symlink points to */
491 struct file __rcu *exe_file;
492 #ifdef CONFIG_MMU_NOTIFIER
493 struct mmu_notifier_mm *mmu_notifier_mm;
494 #endif
495 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
496 pgtable_t pmd_huge_pte; /* protected by page_table_lock */
497 #endif
498 #ifdef CONFIG_NUMA_BALANCING
499 /*
500 * numa_next_scan is the next time that the PTEs will be marked
501 * pte_numa. NUMA hinting faults will gather statistics and
502 * migrate pages to new nodes if necessary.
503 */
504 unsigned long numa_next_scan;
505
506 /* Restart point for scanning and setting pte_numa */
507 unsigned long numa_scan_offset;
508
509 /* numa_scan_seq prevents two threads setting pte_numa */
510 int numa_scan_seq;
511 #endif
512 /*
513 * An operation with batched TLB flushing is going on. Anything
514 * that can move process memory needs to flush the TLB when
515 * moving a PROT_NONE or PROT_NUMA mapped page.
516 */
517 atomic_t tlb_flush_pending;
518 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
519 /* See flush_tlb_batched_pending() */
520 bool tlb_flush_batched;
521 #endif
522 struct uprobes_state uprobes_state;
523 #ifdef CONFIG_HUGETLB_PAGE
524 atomic_long_t hugetlb_usage;
525 #endif
526 struct work_struct async_put_work;
527 } __randomize_layout;
528
529 /*
530 * The mm_cpumask needs to be at the end of mm_struct, because it
531 * is dynamically sized based on nr_cpu_ids.
532 */
533 unsigned long cpu_bitmap[];
534 };
535
536 extern struct mm_struct init_mm;
537
538 /* Pointer magic because the dynamic array size confuses some compilers. */
mm_init_cpumask(struct mm_struct * mm)539 static inline void mm_init_cpumask(struct mm_struct *mm)
540 {
541 unsigned long cpu_bitmap = (unsigned long)mm;
542
543 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap);
544 cpumask_clear((struct cpumask *)cpu_bitmap);
545 }
546
547 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
mm_cpumask(struct mm_struct * mm)548 static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
549 {
550 return (struct cpumask *)&mm->cpu_bitmap;
551 }
552
553 struct mmu_gather;
554 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
555 unsigned long start, unsigned long end);
556 extern void tlb_finish_mmu(struct mmu_gather *tlb,
557 unsigned long start, unsigned long end);
558
init_tlb_flush_pending(struct mm_struct * mm)559 static inline void init_tlb_flush_pending(struct mm_struct *mm)
560 {
561 atomic_set(&mm->tlb_flush_pending, 0);
562 }
563
inc_tlb_flush_pending(struct mm_struct * mm)564 static inline void inc_tlb_flush_pending(struct mm_struct *mm)
565 {
566 atomic_inc(&mm->tlb_flush_pending);
567 /*
568 * The only time this value is relevant is when there are indeed pages
569 * to flush. And we'll only flush pages after changing them, which
570 * requires the PTL.
571 *
572 * So the ordering here is:
573 *
574 * atomic_inc(&mm->tlb_flush_pending);
575 * spin_lock(&ptl);
576 * ...
577 * set_pte_at();
578 * spin_unlock(&ptl);
579 *
580 * spin_lock(&ptl)
581 * mm_tlb_flush_pending();
582 * ....
583 * spin_unlock(&ptl);
584 *
585 * flush_tlb_range();
586 * atomic_dec(&mm->tlb_flush_pending);
587 *
588 * Where the increment if constrained by the PTL unlock, it thus
589 * ensures that the increment is visible if the PTE modification is
590 * visible. After all, if there is no PTE modification, nobody cares
591 * about TLB flushes either.
592 *
593 * This very much relies on users (mm_tlb_flush_pending() and
594 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
595 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
596 * locks (PPC) the unlock of one doesn't order against the lock of
597 * another PTL.
598 *
599 * The decrement is ordered by the flush_tlb_range(), such that
600 * mm_tlb_flush_pending() will not return false unless all flushes have
601 * completed.
602 */
603 }
604
dec_tlb_flush_pending(struct mm_struct * mm)605 static inline void dec_tlb_flush_pending(struct mm_struct *mm)
606 {
607 /*
608 * See inc_tlb_flush_pending().
609 *
610 * This cannot be smp_mb__before_atomic() because smp_mb() simply does
611 * not order against TLB invalidate completion, which is what we need.
612 *
613 * Therefore we must rely on tlb_flush_*() to guarantee order.
614 */
615 atomic_dec(&mm->tlb_flush_pending);
616 }
617
mm_tlb_flush_pending(struct mm_struct * mm)618 static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
619 {
620 /*
621 * Must be called after having acquired the PTL; orders against that
622 * PTLs release and therefore ensures that if we observe the modified
623 * PTE we must also observe the increment from inc_tlb_flush_pending().
624 *
625 * That is, it only guarantees to return true if there is a flush
626 * pending for _this_ PTL.
627 */
628 return atomic_read(&mm->tlb_flush_pending);
629 }
630
mm_tlb_flush_nested(struct mm_struct * mm)631 static inline bool mm_tlb_flush_nested(struct mm_struct *mm)
632 {
633 /*
634 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL
635 * for which there is a TLB flush pending in order to guarantee
636 * we've seen both that PTE modification and the increment.
637 *
638 * (no requirement on actually still holding the PTL, that is irrelevant)
639 */
640 return atomic_read(&mm->tlb_flush_pending) > 1;
641 }
642
643 struct vm_fault;
644
645 /**
646 * typedef vm_fault_t - Return type for page fault handlers.
647 *
648 * Page fault handlers return a bitmask of %VM_FAULT values.
649 */
650 typedef __bitwise unsigned int vm_fault_t;
651
652 /**
653 * enum vm_fault_reason - Page fault handlers return a bitmask of
654 * these values to tell the core VM what happened when handling the
655 * fault. Used to decide whether a process gets delivered SIGBUS or
656 * just gets major/minor fault counters bumped up.
657 *
658 * @VM_FAULT_OOM: Out Of Memory
659 * @VM_FAULT_SIGBUS: Bad access
660 * @VM_FAULT_MAJOR: Page read from storage
661 * @VM_FAULT_WRITE: Special case for get_user_pages
662 * @VM_FAULT_HWPOISON: Hit poisoned small page
663 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded
664 * in upper bits
665 * @VM_FAULT_SIGSEGV: segmentation fault
666 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page
667 * @VM_FAULT_LOCKED: ->fault locked the returned page
668 * @VM_FAULT_RETRY: ->fault blocked, must retry
669 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small
670 * @VM_FAULT_DONE_COW: ->fault has fully handled COW
671 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs
672 * fsync() to complete (for synchronous page faults
673 * in DAX)
674 * @VM_FAULT_HINDEX_MASK: mask HINDEX value
675 *
676 */
677 enum vm_fault_reason {
678 VM_FAULT_OOM = (__force vm_fault_t)0x000001,
679 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002,
680 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004,
681 VM_FAULT_WRITE = (__force vm_fault_t)0x000008,
682 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010,
683 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020,
684 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040,
685 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100,
686 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200,
687 VM_FAULT_RETRY = (__force vm_fault_t)0x000400,
688 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800,
689 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000,
690 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000,
691 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000,
692 };
693
694 /* Encode hstate index for a hwpoisoned large page */
695 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))
696 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf)
697
698 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \
699 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \
700 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK)
701
702 #define VM_FAULT_RESULT_TRACE \
703 { VM_FAULT_OOM, "OOM" }, \
704 { VM_FAULT_SIGBUS, "SIGBUS" }, \
705 { VM_FAULT_MAJOR, "MAJOR" }, \
706 { VM_FAULT_WRITE, "WRITE" }, \
707 { VM_FAULT_HWPOISON, "HWPOISON" }, \
708 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \
709 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \
710 { VM_FAULT_NOPAGE, "NOPAGE" }, \
711 { VM_FAULT_LOCKED, "LOCKED" }, \
712 { VM_FAULT_RETRY, "RETRY" }, \
713 { VM_FAULT_FALLBACK, "FALLBACK" }, \
714 { VM_FAULT_DONE_COW, "DONE_COW" }, \
715 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
716
717 struct vm_special_mapping {
718 const char *name; /* The name, e.g. "[vdso]". */
719
720 /*
721 * If .fault is not provided, this points to a
722 * NULL-terminated array of pages that back the special mapping.
723 *
724 * This must not be NULL unless .fault is provided.
725 */
726 struct page **pages;
727
728 /*
729 * If non-NULL, then this is called to resolve page faults
730 * on the special mapping. If used, .pages is not checked.
731 */
732 vm_fault_t (*fault)(const struct vm_special_mapping *sm,
733 struct vm_area_struct *vma,
734 struct vm_fault *vmf);
735
736 int (*mremap)(const struct vm_special_mapping *sm,
737 struct vm_area_struct *new_vma);
738 };
739
740 enum tlb_flush_reason {
741 TLB_FLUSH_ON_TASK_SWITCH,
742 TLB_REMOTE_SHOOTDOWN,
743 TLB_LOCAL_SHOOTDOWN,
744 TLB_LOCAL_MM_SHOOTDOWN,
745 TLB_REMOTE_SEND_IPI,
746 NR_TLB_FLUSH_REASONS,
747 };
748
749 /*
750 * A swap entry has to fit into a "unsigned long", as the entry is hidden
751 * in the "index" field of the swapper address space.
752 */
753 typedef struct {
754 unsigned long val;
755 } swp_entry_t;
756
757 #endif /* _LINUX_MM_TYPES_H */
758
