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/kref.h>
9#include <linux/list.h>
10#include <linux/spinlock.h>
11#include <linux/rbtree.h>
12#include <linux/rwsem.h>
13#include <linux/completion.h>
14#include <linux/cpumask.h>
15#include <linux/uprobes.h>
16#include <linux/rcupdate.h>
17#include <linux/page-flags-layout.h>
18#include <linux/workqueue.h>
19#include <linux/seqlock.h>
20
21#include <asm/mmu.h>
22
23#ifndef AT_VECTOR_SIZE_ARCH
24#define AT_VECTOR_SIZE_ARCH 0
25#endif
26#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
27
28#define INIT_PASID 0
29
30struct address_space;
31struct mem_cgroup;
32
33/*
34 * Each physical page in the system has a struct page associated with
35 * it to keep track of whatever it is we are using the page for at the
36 * moment. Note that we have no way to track which tasks are using
37 * a page, though if it is a pagecache page, rmap structures can tell us
38 * who is mapping it.
39 *
40 * If you allocate the page using alloc_pages(), you can use some of the
41 * space in struct page for your own purposes. The five words in the main
42 * union are available, except for bit 0 of the first word which must be
43 * kept clear. Many users use this word to store a pointer to an object
44 * which is guaranteed to be aligned. If you use the same storage as
45 * page->mapping, you must restore it to NULL before freeing the page.
46 *
47 * If your page will not be mapped to userspace, you can also use the four
48 * bytes in the mapcount union, but you must call page_mapcount_reset()
49 * before freeing it.
50 *
51 * If you want to use the refcount field, it must be used in such a way
52 * that other CPUs temporarily incrementing and then decrementing the
53 * refcount does not cause problems. On receiving the page from
54 * alloc_pages(), the refcount will be positive.
55 *
56 * If you allocate pages of order > 0, you can use some of the fields
57 * in each subpage, but you may need to restore some of their values
58 * afterwards.
59 *
60 * SLUB uses cmpxchg_double() to atomically update its freelist and counters.
61 * That requires that freelist & counters in struct slab be adjacent and
62 * double-word aligned. Because struct slab currently just reinterprets the
63 * bits of struct page, we align all struct pages to double-word boundaries,
64 * and ensure that 'freelist' is aligned within struct slab.
65 */
66#ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
67#define _struct_page_alignment __aligned(2 * sizeof(unsigned long))
68#else
69#define _struct_page_alignment
70#endif
71
72struct page {
73 unsigned long flags; /* Atomic flags, some possibly
74 * updated asynchronously */
75 /*
76 * Five words (20/40 bytes) are available in this union.
77 * WARNING: bit 0 of the first word is used for PageTail(). That
78 * means the other users of this union MUST NOT use the bit to
79 * avoid collision and false-positive PageTail().
80 */
81 union {
82 struct { /* Page cache and anonymous pages */
83 /**
84 * @lru: Pageout list, eg. active_list protected by
85 * lruvec->lru_lock. Sometimes used as a generic list
86 * by the page owner.
87 */
88 union {
89 struct list_head lru;
90
91 /* Or, for the Unevictable "LRU list" slot */
92 struct {
93 /* Always even, to negate PageTail */
94 void *__filler;
95 /* Count page's or folio's mlocks */
96 unsigned int mlock_count;
97 };
98
99 /* Or, free page */
100 struct list_head buddy_list;
101 struct list_head pcp_list;
102 };
103 /* See page-flags.h for PAGE_MAPPING_FLAGS */
104 struct address_space *mapping;
105 pgoff_t index; /* Our offset within mapping. */
106 /**
107 * @private: Mapping-private opaque data.
108 * Usually used for buffer_heads if PagePrivate.
109 * Used for swp_entry_t if PageSwapCache.
110 * Indicates order in the buddy system if PageBuddy.
111 */
112 unsigned long private;
113 };
114 struct { /* page_pool used by netstack */
115 /**
116 * @pp_magic: magic value to avoid recycling non
117 * page_pool allocated pages.
118 */
119 unsigned long pp_magic;
120 struct page_pool *pp;
121 unsigned long _pp_mapping_pad;
122 unsigned long dma_addr;
123 union {
124 /**
125 * dma_addr_upper: might require a 64-bit
126 * value on 32-bit architectures.
127 */
128 unsigned long dma_addr_upper;
129 /**
130 * For frag page support, not supported in
131 * 32-bit architectures with 64-bit DMA.
132 */
133 atomic_long_t pp_frag_count;
134 };
135 };
136 struct { /* Tail pages of compound page */
137 unsigned long compound_head; /* Bit zero is set */
138
139 /* First tail page only */
140 unsigned char compound_dtor;
141 unsigned char compound_order;
142 atomic_t compound_mapcount;
143 atomic_t compound_pincount;
144#ifdef CONFIG_64BIT
145 unsigned int compound_nr; /* 1 << compound_order */
146#endif
147 };
148 struct { /* Second tail page of compound page */
149 unsigned long _compound_pad_1; /* compound_head */
150 unsigned long _compound_pad_2;
151 /* For both global and memcg */
152 struct list_head deferred_list;
153 };
154 struct { /* Page table pages */
155 unsigned long _pt_pad_1; /* compound_head */
156 pgtable_t pmd_huge_pte; /* protected by page->ptl */
157 unsigned long _pt_pad_2; /* mapping */
158 union {
159 struct mm_struct *pt_mm; /* x86 pgds only */
160 atomic_t pt_frag_refcount; /* powerpc */
161 };
162#if ALLOC_SPLIT_PTLOCKS
163 spinlock_t *ptl;
164#else
165 spinlock_t ptl;
166#endif
167 };
168 struct { /* ZONE_DEVICE pages */
169 /** @pgmap: Points to the hosting device page map. */
170 struct dev_pagemap *pgmap;
171 void *zone_device_data;
172 /*
173 * ZONE_DEVICE private pages are counted as being
174 * mapped so the next 3 words hold the mapping, index,
175 * and private fields from the source anonymous or
176 * page cache page while the page is migrated to device
177 * private memory.
178 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
179 * use the mapping, index, and private fields when
180 * pmem backed DAX files are mapped.
181 */
182 };
183
184 /** @rcu_head: You can use this to free a page by RCU. */
185 struct rcu_head rcu_head;
186 };
187
188 union { /* This union is 4 bytes in size. */
189 /*
190 * If the page can be mapped to userspace, encodes the number
191 * of times this page is referenced by a page table.
192 */
193 atomic_t _mapcount;
194
195 /*
196 * If the page is neither PageSlab nor mappable to userspace,
197 * the value stored here may help determine what this page
198 * is used for. See page-flags.h for a list of page types
199 * which are currently stored here.
200 */
201 unsigned int page_type;
202 };
203
204 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */
205 atomic_t _refcount;
206
207#ifdef CONFIG_MEMCG
208 unsigned long memcg_data;
209#endif
210
211 /*
212 * On machines where all RAM is mapped into kernel address space,
213 * we can simply calculate the virtual address. On machines with
214 * highmem some memory is mapped into kernel virtual memory
215 * dynamically, so we need a place to store that address.
216 * Note that this field could be 16 bits on x86 ... ;)
217 *
218 * Architectures with slow multiplication can define
219 * WANT_PAGE_VIRTUAL in asm/page.h
220 */
221#if defined(WANT_PAGE_VIRTUAL)
222 void *virtual; /* Kernel virtual address (NULL if
223 not kmapped, ie. highmem) */
224#endif /* WANT_PAGE_VIRTUAL */
225
226#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
227 int _last_cpupid;
228#endif
229} _struct_page_alignment;
230
231/**
232 * struct folio - Represents a contiguous set of bytes.
233 * @flags: Identical to the page flags.
234 * @lru: Least Recently Used list; tracks how recently this folio was used.
235 * @mlock_count: Number of times this folio has been pinned by mlock().
236 * @mapping: The file this page belongs to, or refers to the anon_vma for
237 * anonymous memory.
238 * @index: Offset within the file, in units of pages. For anonymous memory,
239 * this is the index from the beginning of the mmap.
240 * @private: Filesystem per-folio data (see folio_attach_private()).
241 * Used for swp_entry_t if folio_test_swapcache().
242 * @_mapcount: Do not access this member directly. Use folio_mapcount() to
243 * find out how many times this folio is mapped by userspace.
244 * @_refcount: Do not access this member directly. Use folio_ref_count()
245 * to find how many references there are to this folio.
246 * @memcg_data: Memory Control Group data.
247 *
248 * A folio is a physically, virtually and logically contiguous set
249 * of bytes. It is a power-of-two in size, and it is aligned to that
250 * same power-of-two. It is at least as large as %PAGE_SIZE. If it is
251 * in the page cache, it is at a file offset which is a multiple of that
252 * power-of-two. It may be mapped into userspace at an address which is
253 * at an arbitrary page offset, but its kernel virtual address is aligned
254 * to its size.
255 */
256struct folio {
257 /* private: don't document the anon union */
258 union {
259 struct {
260 /* public: */
261 unsigned long flags;
262 union {
263 struct list_head lru;
264 /* private: avoid cluttering the output */
265 struct {
266 void *__filler;
267 /* public: */
268 unsigned int mlock_count;
269 /* private: */
270 };
271 /* public: */
272 };
273 struct address_space *mapping;
274 pgoff_t index;
275 void *private;
276 atomic_t _mapcount;
277 atomic_t _refcount;
278#ifdef CONFIG_MEMCG
279 unsigned long memcg_data;
280#endif
281 /* private: the union with struct page is transitional */
282 };
283 struct page page;
284 };
285};
286
287static_assert(sizeof(struct page) == sizeof(struct folio));
288#define FOLIO_MATCH(pg, fl) \
289 static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl))
290FOLIO_MATCH(flags, flags);
291FOLIO_MATCH(lru, lru);
292FOLIO_MATCH(mapping, mapping);
293FOLIO_MATCH(compound_head, lru);
294FOLIO_MATCH(index, index);
295FOLIO_MATCH(private, private);
296FOLIO_MATCH(_mapcount, _mapcount);
297FOLIO_MATCH(_refcount, _refcount);
298#ifdef CONFIG_MEMCG
299FOLIO_MATCH(memcg_data, memcg_data);
300#endif
301#undef FOLIO_MATCH
302
303static inline atomic_t *folio_mapcount_ptr(struct folio *folio)
304{
305 struct page *tail = &folio->page + 1;
306 return &tail->compound_mapcount;
307}
308
309static inline atomic_t *compound_mapcount_ptr(struct page *page)
310{
311 return &page[1].compound_mapcount;
312}
313
314static inline atomic_t *compound_pincount_ptr(struct page *page)
315{
316 return &page[1].compound_pincount;
317}
318
319/*
320 * Used for sizing the vmemmap region on some architectures
321 */
322#define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page)))
323
324#define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
325#define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
326
327/*
328 * page_private can be used on tail pages. However, PagePrivate is only
329 * checked by the VM on the head page. So page_private on the tail pages
330 * should be used for data that's ancillary to the head page (eg attaching
331 * buffer heads to tail pages after attaching buffer heads to the head page)
332 */
333#define page_private(page) ((page)->private)
334
335static inline void set_page_private(struct page *page, unsigned long private)
336{
337 page->private = private;
338}
339
340static inline void *folio_get_private(struct folio *folio)
341{
342 return folio->private;
343}
344
345struct page_frag_cache {
346 void * va;
347#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
348 __u16 offset;
349 __u16 size;
350#else
351 __u32 offset;
352#endif
353 /* we maintain a pagecount bias, so that we dont dirty cache line
354 * containing page->_refcount every time we allocate a fragment.
355 */
356 unsigned int pagecnt_bias;
357 bool pfmemalloc;
358};
359
360typedef unsigned long vm_flags_t;
361
362/*
363 * A region containing a mapping of a non-memory backed file under NOMMU
364 * conditions. These are held in a global tree and are pinned by the VMAs that
365 * map parts of them.
366 */
367struct vm_region {
368 struct rb_node vm_rb; /* link in global region tree */
369 vm_flags_t vm_flags; /* VMA vm_flags */
370 unsigned long vm_start; /* start address of region */
371 unsigned long vm_end; /* region initialised to here */
372 unsigned long vm_top; /* region allocated to here */
373 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
374 struct file *vm_file; /* the backing file or NULL */
375
376 int vm_usage; /* region usage count (access under nommu_region_sem) */
377 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
378 * this region */
379};
380
381#ifdef CONFIG_USERFAULTFD
382#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, })
383struct vm_userfaultfd_ctx {
384 struct userfaultfd_ctx *ctx;
385};
386#else /* CONFIG_USERFAULTFD */
387#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {})
388struct vm_userfaultfd_ctx {};
389#endif /* CONFIG_USERFAULTFD */
390
391struct anon_vma_name {
392 struct kref kref;
393 /* The name needs to be at the end because it is dynamically sized. */
394 char name[];
395};
396
397/*
398 * This struct describes a virtual memory area. There is one of these
399 * per VM-area/task. A VM area is any part of the process virtual memory
400 * space that has a special rule for the page-fault handlers (ie a shared
401 * library, the executable area etc).
402 */
403struct vm_area_struct {
404 /* The first cache line has the info for VMA tree walking. */
405
406 unsigned long vm_start; /* Our start address within vm_mm. */
407 unsigned long vm_end; /* The first byte after our end address
408 within vm_mm. */
409
410 /* linked list of VM areas per task, sorted by address */
411 struct vm_area_struct *vm_next, *vm_prev;
412
413 struct rb_node vm_rb;
414
415 /*
416 * Largest free memory gap in bytes to the left of this VMA.
417 * Either between this VMA and vma->vm_prev, or between one of the
418 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
419 * get_unmapped_area find a free area of the right size.
420 */
421 unsigned long rb_subtree_gap;
422
423 /* Second cache line starts here. */
424
425 struct mm_struct *vm_mm; /* The address space we belong to. */
426
427 /*
428 * Access permissions of this VMA.
429 * See vmf_insert_mixed_prot() for discussion.
430 */
431 pgprot_t vm_page_prot;
432 unsigned long vm_flags; /* Flags, see mm.h. */
433
434 /*
435 * For areas with an address space and backing store,
436 * linkage into the address_space->i_mmap interval tree.
437 *
438 * For private anonymous mappings, a pointer to a null terminated string
439 * containing the name given to the vma, or NULL if unnamed.
440 */
441
442 union {
443 struct {
444 struct rb_node rb;
445 unsigned long rb_subtree_last;
446 } shared;
447 /*
448 * Serialized by mmap_sem. Never use directly because it is
449 * valid only when vm_file is NULL. Use anon_vma_name instead.
450 */
451 struct anon_vma_name *anon_name;
452 };
453
454 /*
455 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
456 * list, after a COW of one of the file pages. A MAP_SHARED vma
457 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
458 * or brk vma (with NULL file) can only be in an anon_vma list.
459 */
460 struct list_head anon_vma_chain; /* Serialized by mmap_lock &
461 * page_table_lock */
462 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
463
464 /* Function pointers to deal with this struct. */
465 const struct vm_operations_struct *vm_ops;
466
467 /* Information about our backing store: */
468 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
469 units */
470 struct file * vm_file; /* File we map to (can be NULL). */
471 void * vm_private_data; /* was vm_pte (shared mem) */
472
473#ifdef CONFIG_SWAP
474 atomic_long_t swap_readahead_info;
475#endif
476#ifndef CONFIG_MMU
477 struct vm_region *vm_region; /* NOMMU mapping region */
478#endif
479#ifdef CONFIG_NUMA
480 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
481#endif
482 struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
483} __randomize_layout;
484
485struct kioctx_table;
486struct mm_struct {
487 struct {
488 struct vm_area_struct *mmap; /* list of VMAs */
489 struct rb_root mm_rb;
490 u64 vmacache_seqnum; /* per-thread vmacache */
491#ifdef CONFIG_MMU
492 unsigned long (*get_unmapped_area) (struct file *filp,
493 unsigned long addr, unsigned long len,
494 unsigned long pgoff, unsigned long flags);
495#endif
496 unsigned long mmap_base; /* base of mmap area */
497 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
498#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
499 /* Base addresses for compatible mmap() */
500 unsigned long mmap_compat_base;
501 unsigned long mmap_compat_legacy_base;
502#endif
503 unsigned long task_size; /* size of task vm space */
504 unsigned long highest_vm_end; /* highest vma end address */
505 pgd_t * pgd;
506
507#ifdef CONFIG_MEMBARRIER
508 /**
509 * @membarrier_state: Flags controlling membarrier behavior.
510 *
511 * This field is close to @pgd to hopefully fit in the same
512 * cache-line, which needs to be touched by switch_mm().
513 */
514 atomic_t membarrier_state;
515#endif
516
517 /**
518 * @mm_users: The number of users including userspace.
519 *
520 * Use mmget()/mmget_not_zero()/mmput() to modify. When this
521 * drops to 0 (i.e. when the task exits and there are no other
522 * temporary reference holders), we also release a reference on
523 * @mm_count (which may then free the &struct mm_struct if
524 * @mm_count also drops to 0).
525 */
526 atomic_t mm_users;
527
528 /**
529 * @mm_count: The number of references to &struct mm_struct
530 * (@mm_users count as 1).
531 *
532 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the
533 * &struct mm_struct is freed.
534 */
535 atomic_t mm_count;
536
537#ifdef CONFIG_MMU
538 atomic_long_t pgtables_bytes; /* PTE page table pages */
539#endif
540 int map_count; /* number of VMAs */
541
542 spinlock_t page_table_lock; /* Protects page tables and some
543 * counters
544 */
545 /*
546 * With some kernel config, the current mmap_lock's offset
547 * inside 'mm_struct' is at 0x120, which is very optimal, as
548 * its two hot fields 'count' and 'owner' sit in 2 different
549 * cachelines, and when mmap_lock is highly contended, both
550 * of the 2 fields will be accessed frequently, current layout
551 * will help to reduce cache bouncing.
552 *
553 * So please be careful with adding new fields before
554 * mmap_lock, which can easily push the 2 fields into one
555 * cacheline.
556 */
557 struct rw_semaphore mmap_lock;
558
559 struct list_head mmlist; /* List of maybe swapped mm's. These
560 * are globally strung together off
561 * init_mm.mmlist, and are protected
562 * by mmlist_lock
563 */
564
565
566 unsigned long hiwater_rss; /* High-watermark of RSS usage */
567 unsigned long hiwater_vm; /* High-water virtual memory usage */
568
569 unsigned long total_vm; /* Total pages mapped */
570 unsigned long locked_vm; /* Pages that have PG_mlocked set */
571 atomic64_t pinned_vm; /* Refcount permanently increased */
572 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
573 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
574 unsigned long stack_vm; /* VM_STACK */
575 unsigned long def_flags;
576
577 /**
578 * @write_protect_seq: Locked when any thread is write
579 * protecting pages mapped by this mm to enforce a later COW,
580 * for instance during page table copying for fork().
581 */
582 seqcount_t write_protect_seq;
583
584 spinlock_t arg_lock; /* protect the below fields */
585
586 unsigned long start_code, end_code, start_data, end_data;
587 unsigned long start_brk, brk, start_stack;
588 unsigned long arg_start, arg_end, env_start, env_end;
589
590 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
591
592 /*
593 * Special counters, in some configurations protected by the
594 * page_table_lock, in other configurations by being atomic.
595 */
596 struct mm_rss_stat rss_stat;
597
598 struct linux_binfmt *binfmt;
599
600 /* Architecture-specific MM context */
601 mm_context_t context;
602
603 unsigned long flags; /* Must use atomic bitops to access */
604
605#ifdef CONFIG_AIO
606 spinlock_t ioctx_lock;
607 struct kioctx_table __rcu *ioctx_table;
608#endif
609#ifdef CONFIG_MEMCG
610 /*
611 * "owner" points to a task that is regarded as the canonical
612 * user/owner of this mm. All of the following must be true in
613 * order for it to be changed:
614 *
615 * current == mm->owner
616 * current->mm != mm
617 * new_owner->mm == mm
618 * new_owner->alloc_lock is held
619 */
620 struct task_struct __rcu *owner;
621#endif
622 struct user_namespace *user_ns;
623
624 /* store ref to file /proc/<pid>/exe symlink points to */
625 struct file __rcu *exe_file;
626#ifdef CONFIG_MMU_NOTIFIER
627 struct mmu_notifier_subscriptions *notifier_subscriptions;
628#endif
629#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
630 pgtable_t pmd_huge_pte; /* protected by page_table_lock */
631#endif
632#ifdef CONFIG_NUMA_BALANCING
633 /*
634 * numa_next_scan is the next time that the PTEs will be marked
635 * pte_numa. NUMA hinting faults will gather statistics and
636 * migrate pages to new nodes if necessary.
637 */
638 unsigned long numa_next_scan;
639
640 /* Restart point for scanning and setting pte_numa */
641 unsigned long numa_scan_offset;
642
643 /* numa_scan_seq prevents two threads setting pte_numa */
644 int numa_scan_seq;
645#endif
646 /*
647 * An operation with batched TLB flushing is going on. Anything
648 * that can move process memory needs to flush the TLB when
649 * moving a PROT_NONE or PROT_NUMA mapped page.
650 */
651 atomic_t tlb_flush_pending;
652#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
653 /* See flush_tlb_batched_pending() */
654 atomic_t tlb_flush_batched;
655#endif
656 struct uprobes_state uprobes_state;
657#ifdef CONFIG_PREEMPT_RT
658 struct rcu_head delayed_drop;
659#endif
660#ifdef CONFIG_HUGETLB_PAGE
661 atomic_long_t hugetlb_usage;
662#endif
663 struct work_struct async_put_work;
664
665#ifdef CONFIG_IOMMU_SVA
666 u32 pasid;
667#endif
668#ifdef CONFIG_KSM
669 /*
670 * Represent how many pages of this process are involved in KSM
671 * merging.
672 */
673 unsigned long ksm_merging_pages;
674#endif
675 } __randomize_layout;
676
677 /*
678 * The mm_cpumask needs to be at the end of mm_struct, because it
679 * is dynamically sized based on nr_cpu_ids.
680 */
681 unsigned long cpu_bitmap[];
682};
683
684extern struct mm_struct init_mm;
685
686/* Pointer magic because the dynamic array size confuses some compilers. */
687static inline void mm_init_cpumask(struct mm_struct *mm)
688{
689 unsigned long cpu_bitmap = (unsigned long)mm;
690
691 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap);
692 cpumask_clear((struct cpumask *)cpu_bitmap);
693}
694
695/* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
696static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
697{
698 return (struct cpumask *)&mm->cpu_bitmap;
699}
700
701struct mmu_gather;
702extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm);
703extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm);
704extern void tlb_finish_mmu(struct mmu_gather *tlb);
705
706struct vm_fault;
707
708/**
709 * typedef vm_fault_t - Return type for page fault handlers.
710 *
711 * Page fault handlers return a bitmask of %VM_FAULT values.
712 */
713typedef __bitwise unsigned int vm_fault_t;
714
715/**
716 * enum vm_fault_reason - Page fault handlers return a bitmask of
717 * these values to tell the core VM what happened when handling the
718 * fault. Used to decide whether a process gets delivered SIGBUS or
719 * just gets major/minor fault counters bumped up.
720 *
721 * @VM_FAULT_OOM: Out Of Memory
722 * @VM_FAULT_SIGBUS: Bad access
723 * @VM_FAULT_MAJOR: Page read from storage
724 * @VM_FAULT_WRITE: Special case for get_user_pages
725 * @VM_FAULT_HWPOISON: Hit poisoned small page
726 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded
727 * in upper bits
728 * @VM_FAULT_SIGSEGV: segmentation fault
729 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page
730 * @VM_FAULT_LOCKED: ->fault locked the returned page
731 * @VM_FAULT_RETRY: ->fault blocked, must retry
732 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small
733 * @VM_FAULT_DONE_COW: ->fault has fully handled COW
734 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs
735 * fsync() to complete (for synchronous page faults
736 * in DAX)
737 * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released
738 * @VM_FAULT_HINDEX_MASK: mask HINDEX value
739 *
740 */
741enum vm_fault_reason {
742 VM_FAULT_OOM = (__force vm_fault_t)0x000001,
743 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002,
744 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004,
745 VM_FAULT_WRITE = (__force vm_fault_t)0x000008,
746 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010,
747 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020,
748 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040,
749 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100,
750 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200,
751 VM_FAULT_RETRY = (__force vm_fault_t)0x000400,
752 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800,
753 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000,
754 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000,
755 VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000,
756 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000,
757};
758
759/* Encode hstate index for a hwpoisoned large page */
760#define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))
761#define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf)
762
763#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \
764 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \
765 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK)
766
767#define VM_FAULT_RESULT_TRACE \
768 { VM_FAULT_OOM, "OOM" }, \
769 { VM_FAULT_SIGBUS, "SIGBUS" }, \
770 { VM_FAULT_MAJOR, "MAJOR" }, \
771 { VM_FAULT_WRITE, "WRITE" }, \
772 { VM_FAULT_HWPOISON, "HWPOISON" }, \
773 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \
774 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \
775 { VM_FAULT_NOPAGE, "NOPAGE" }, \
776 { VM_FAULT_LOCKED, "LOCKED" }, \
777 { VM_FAULT_RETRY, "RETRY" }, \
778 { VM_FAULT_FALLBACK, "FALLBACK" }, \
779 { VM_FAULT_DONE_COW, "DONE_COW" }, \
780 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
781
782struct vm_special_mapping {
783 const char *name; /* The name, e.g. "[vdso]". */
784
785 /*
786 * If .fault is not provided, this points to a
787 * NULL-terminated array of pages that back the special mapping.
788 *
789 * This must not be NULL unless .fault is provided.
790 */
791 struct page **pages;
792
793 /*
794 * If non-NULL, then this is called to resolve page faults
795 * on the special mapping. If used, .pages is not checked.
796 */
797 vm_fault_t (*fault)(const struct vm_special_mapping *sm,
798 struct vm_area_struct *vma,
799 struct vm_fault *vmf);
800
801 int (*mremap)(const struct vm_special_mapping *sm,
802 struct vm_area_struct *new_vma);
803};
804
805enum tlb_flush_reason {
806 TLB_FLUSH_ON_TASK_SWITCH,
807 TLB_REMOTE_SHOOTDOWN,
808 TLB_LOCAL_SHOOTDOWN,
809 TLB_LOCAL_MM_SHOOTDOWN,
810 TLB_REMOTE_SEND_IPI,
811 NR_TLB_FLUSH_REASONS,
812};
813
814 /*
815 * A swap entry has to fit into a "unsigned long", as the entry is hidden
816 * in the "index" field of the swapper address space.
817 */
818typedef struct {
819 unsigned long val;
820} swp_entry_t;
821
822/**
823 * enum fault_flag - Fault flag definitions.
824 * @FAULT_FLAG_WRITE: Fault was a write fault.
825 * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE.
826 * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked.
827 * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying.
828 * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region.
829 * @FAULT_FLAG_TRIED: The fault has been tried once.
830 * @FAULT_FLAG_USER: The fault originated in userspace.
831 * @FAULT_FLAG_REMOTE: The fault is not for current task/mm.
832 * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch.
833 * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals.
834 * @FAULT_FLAG_UNSHARE: The fault is an unsharing request to unshare (and mark
835 * exclusive) a possibly shared anonymous page that is
836 * mapped R/O.
837 * @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached.
838 * We should only access orig_pte if this flag set.
839 *
840 * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify
841 * whether we would allow page faults to retry by specifying these two
842 * fault flags correctly. Currently there can be three legal combinations:
843 *
844 * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and
845 * this is the first try
846 *
847 * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and
848 * we've already tried at least once
849 *
850 * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry
851 *
852 * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never
853 * be used. Note that page faults can be allowed to retry for multiple times,
854 * in which case we'll have an initial fault with flags (a) then later on
855 * continuous faults with flags (b). We should always try to detect pending
856 * signals before a retry to make sure the continuous page faults can still be
857 * interrupted if necessary.
858 *
859 * The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal.
860 * FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when
861 * no existing R/O-mapped anonymous page is encountered.
862 */
863enum fault_flag {
864 FAULT_FLAG_WRITE = 1 << 0,
865 FAULT_FLAG_MKWRITE = 1 << 1,
866 FAULT_FLAG_ALLOW_RETRY = 1 << 2,
867 FAULT_FLAG_RETRY_NOWAIT = 1 << 3,
868 FAULT_FLAG_KILLABLE = 1 << 4,
869 FAULT_FLAG_TRIED = 1 << 5,
870 FAULT_FLAG_USER = 1 << 6,
871 FAULT_FLAG_REMOTE = 1 << 7,
872 FAULT_FLAG_INSTRUCTION = 1 << 8,
873 FAULT_FLAG_INTERRUPTIBLE = 1 << 9,
874 FAULT_FLAG_UNSHARE = 1 << 10,
875 FAULT_FLAG_ORIG_PTE_VALID = 1 << 11,
876};
877
878typedef unsigned int __bitwise zap_flags_t;
879
880#endif /* _LINUX_MM_TYPES_H */
881

source code of linux/include/linux/mm_types.h