1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MM_TYPES_H
3 #define _LINUX_MM_TYPES_H
5 #include <linux/mm_types_task.h>
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 #include <linux/seqlock.h>
21 #ifndef AT_VECTOR_SIZE_ARCH
22 #define AT_VECTOR_SIZE_ARCH 0
24 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
32 * Each physical page in the system has a struct page associated with
33 * it to keep track of whatever it is we are using the page for at the
34 * moment. Note that we have no way to track which tasks are using
35 * a page, though if it is a pagecache page, rmap structures can tell us
38 * If you allocate the page using alloc_pages(), you can use some of the
39 * space in struct page for your own purposes. The five words in the main
40 * union are available, except for bit 0 of the first word which must be
41 * kept clear. Many users use this word to store a pointer to an object
42 * which is guaranteed to be aligned. If you use the same storage as
43 * page->mapping, you must restore it to NULL before freeing the page.
45 * If your page will not be mapped to userspace, you can also use the four
46 * bytes in the mapcount union, but you must call page_mapcount_reset()
49 * If you want to use the refcount field, it must be used in such a way
50 * that other CPUs temporarily incrementing and then decrementing the
51 * refcount does not cause problems. On receiving the page from
52 * alloc_pages(), the refcount will be positive.
54 * If you allocate pages of order > 0, you can use some of the fields
55 * in each subpage, but you may need to restore some of their values
58 * SLUB uses cmpxchg_double() to atomically update its freelist and
59 * counters. That requires that freelist & counters be adjacent and
60 * double-word aligned. We align all struct pages to double-word
61 * boundaries, and ensure that 'freelist' is aligned within the
64 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
65 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long))
67 #define _struct_page_alignment
71 unsigned long flags; /* Atomic flags, some possibly
72 * updated asynchronously */
74 * Five words (20/40 bytes) are available in this union.
75 * WARNING: bit 0 of the first word is used for PageTail(). That
76 * means the other users of this union MUST NOT use the bit to
77 * avoid collision and false-positive PageTail().
80 struct { /* Page cache and anonymous pages */
82 * @lru: Pageout list, eg. active_list protected by
83 * pgdat->lru_lock. Sometimes used as a generic list
87 /* See page-flags.h for PAGE_MAPPING_FLAGS */
88 struct address_space *mapping;
89 pgoff_t index; /* Our offset within mapping. */
91 * @private: Mapping-private opaque data.
92 * Usually used for buffer_heads if PagePrivate.
93 * Used for swp_entry_t if PageSwapCache.
94 * Indicates order in the buddy system if PageBuddy.
96 unsigned long private;
98 struct { /* page_pool used by netstack */
100 * @dma_addr: might require a 64-bit value on
101 * 32-bit architectures.
103 unsigned long dma_addr[2];
105 struct { /* slab, slob and slub */
107 struct list_head slab_list;
108 struct { /* Partial pages */
111 int pages; /* Nr of pages left */
112 int pobjects; /* Approximate count */
119 struct kmem_cache *slab_cache; /* not slob */
120 /* Double-word boundary */
121 void *freelist; /* first free object */
123 void *s_mem; /* slab: first object */
124 unsigned long counters; /* SLUB */
132 struct { /* Tail pages of compound page */
133 unsigned long compound_head; /* Bit zero is set */
135 /* First tail page only */
136 unsigned char compound_dtor;
137 unsigned char compound_order;
138 atomic_t compound_mapcount;
139 unsigned int compound_nr; /* 1 << compound_order */
141 struct { /* Second tail page of compound page */
142 unsigned long _compound_pad_1; /* compound_head */
143 atomic_t hpage_pinned_refcount;
144 /* For both global and memcg */
145 struct list_head deferred_list;
147 struct { /* Page table pages */
148 unsigned long _pt_pad_1; /* compound_head */
149 pgtable_t pmd_huge_pte; /* protected by page->ptl */
150 unsigned long _pt_pad_2; /* mapping */
152 struct mm_struct *pt_mm; /* x86 pgds only */
153 atomic_t pt_frag_refcount; /* powerpc */
155 #if ALLOC_SPLIT_PTLOCKS
161 struct { /* ZONE_DEVICE pages */
162 /** @pgmap: Points to the hosting device page map. */
163 struct dev_pagemap *pgmap;
164 void *zone_device_data;
166 * ZONE_DEVICE private pages are counted as being
167 * mapped so the next 3 words hold the mapping, index,
168 * and private fields from the source anonymous or
169 * page cache page while the page is migrated to device
171 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
172 * use the mapping, index, and private fields when
173 * pmem backed DAX files are mapped.
177 /** @rcu_head: You can use this to free a page by RCU. */
178 struct rcu_head rcu_head;
181 union { /* This union is 4 bytes in size. */
183 * If the page can be mapped to userspace, encodes the number
184 * of times this page is referenced by a page table.
189 * If the page is neither PageSlab nor mappable to userspace,
190 * the value stored here may help determine what this page
191 * is used for. See page-flags.h for a list of page types
192 * which are currently stored here.
194 unsigned int page_type;
196 unsigned int active; /* SLAB */
197 int units; /* SLOB */
200 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */
205 struct mem_cgroup *mem_cgroup;
206 struct obj_cgroup **obj_cgroups;
211 * On machines where all RAM is mapped into kernel address space,
212 * we can simply calculate the virtual address. On machines with
213 * highmem some memory is mapped into kernel virtual memory
214 * dynamically, so we need a place to store that address.
215 * Note that this field could be 16 bits on x86 ... ;)
217 * Architectures with slow multiplication can define
218 * WANT_PAGE_VIRTUAL in asm/page.h
220 #if defined(WANT_PAGE_VIRTUAL)
221 void *virtual; /* Kernel virtual address (NULL if
222 not kmapped, ie. highmem) */
223 #endif /* WANT_PAGE_VIRTUAL */
225 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
228 } _struct_page_alignment;
230 static inline atomic_t *compound_mapcount_ptr(struct page *page)
232 return &page[1].compound_mapcount;
235 static inline atomic_t *compound_pincount_ptr(struct page *page)
237 return &page[2].hpage_pinned_refcount;
241 * Used for sizing the vmemmap region on some architectures
243 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page)))
245 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
246 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
248 #define page_private(page) ((page)->private)
250 static inline void set_page_private(struct page *page, unsigned long private)
252 page->private = private;
255 struct page_frag_cache {
257 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
263 /* we maintain a pagecount bias, so that we dont dirty cache line
264 * containing page->_refcount every time we allocate a fragment.
266 unsigned int pagecnt_bias;
270 typedef unsigned long vm_flags_t;
273 * A region containing a mapping of a non-memory backed file under NOMMU
274 * conditions. These are held in a global tree and are pinned by the VMAs that
278 struct rb_node vm_rb; /* link in global region tree */
279 vm_flags_t vm_flags; /* VMA vm_flags */
280 unsigned long vm_start; /* start address of region */
281 unsigned long vm_end; /* region initialised to here */
282 unsigned long vm_top; /* region allocated to here */
283 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
284 struct file *vm_file; /* the backing file or NULL */
286 int vm_usage; /* region usage count (access under nommu_region_sem) */
287 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
291 #ifdef CONFIG_USERFAULTFD
292 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, })
293 struct vm_userfaultfd_ctx {
294 struct userfaultfd_ctx *ctx;
296 #else /* CONFIG_USERFAULTFD */
297 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {})
298 struct vm_userfaultfd_ctx {};
299 #endif /* CONFIG_USERFAULTFD */
302 * This struct describes a virtual memory area. There is one of these
303 * per VM-area/task. A VM area is any part of the process virtual memory
304 * space that has a special rule for the page-fault handlers (ie a shared
305 * library, the executable area etc).
307 struct vm_area_struct {
308 /* The first cache line has the info for VMA tree walking. */
310 unsigned long vm_start; /* Our start address within vm_mm. */
311 unsigned long vm_end; /* The first byte after our end address
314 /* linked list of VM areas per task, sorted by address */
315 struct vm_area_struct *vm_next, *vm_prev;
317 struct rb_node vm_rb;
320 * Largest free memory gap in bytes to the left of this VMA.
321 * Either between this VMA and vma->vm_prev, or between one of the
322 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
323 * get_unmapped_area find a free area of the right size.
325 unsigned long rb_subtree_gap;
327 /* Second cache line starts here. */
329 struct mm_struct *vm_mm; /* The address space we belong to. */
332 * Access permissions of this VMA.
333 * See vmf_insert_mixed_prot() for discussion.
335 pgprot_t vm_page_prot;
336 unsigned long vm_flags; /* Flags, see mm.h. */
339 * For areas with an address space and backing store,
340 * linkage into the address_space->i_mmap interval tree.
344 unsigned long rb_subtree_last;
348 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
349 * list, after a COW of one of the file pages. A MAP_SHARED vma
350 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
351 * or brk vma (with NULL file) can only be in an anon_vma list.
353 struct list_head anon_vma_chain; /* Serialized by mmap_lock &
355 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
357 /* Function pointers to deal with this struct. */
358 const struct vm_operations_struct *vm_ops;
360 /* Information about our backing store: */
361 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
363 struct file * vm_file; /* File we map to (can be NULL). */
364 void * vm_private_data; /* was vm_pte (shared mem) */
367 atomic_long_t swap_readahead_info;
370 struct vm_region *vm_region; /* NOMMU mapping region */
373 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
375 struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
376 } __randomize_layout;
379 struct task_struct *task;
380 struct core_thread *next;
385 struct core_thread dumper;
386 struct completion startup;
392 struct vm_area_struct *mmap; /* list of VMAs */
393 struct rb_root mm_rb;
394 u64 vmacache_seqnum; /* per-thread vmacache */
396 unsigned long (*get_unmapped_area) (struct file *filp,
397 unsigned long addr, unsigned long len,
398 unsigned long pgoff, unsigned long flags);
400 unsigned long mmap_base; /* base of mmap area */
401 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
402 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
403 /* Base adresses for compatible mmap() */
404 unsigned long mmap_compat_base;
405 unsigned long mmap_compat_legacy_base;
407 unsigned long task_size; /* size of task vm space */
408 unsigned long highest_vm_end; /* highest vma end address */
411 #ifdef CONFIG_MEMBARRIER
413 * @membarrier_state: Flags controlling membarrier behavior.
415 * This field is close to @pgd to hopefully fit in the same
416 * cache-line, which needs to be touched by switch_mm().
418 atomic_t membarrier_state;
422 * @mm_users: The number of users including userspace.
424 * Use mmget()/mmget_not_zero()/mmput() to modify. When this
425 * drops to 0 (i.e. when the task exits and there are no other
426 * temporary reference holders), we also release a reference on
427 * @mm_count (which may then free the &struct mm_struct if
428 * @mm_count also drops to 0).
433 * @mm_count: The number of references to &struct mm_struct
434 * (@mm_users count as 1).
436 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the
437 * &struct mm_struct is freed.
442 * @has_pinned: Whether this mm has pinned any pages. This can
443 * be either replaced in the future by @pinned_vm when it
444 * becomes stable, or grow into a counter on its own. We're
445 * aggresive on this bit now - even if the pinned pages were
446 * unpinned later on, we'll still keep this bit set for the
447 * lifecycle of this mm just for simplicity.
452 atomic_long_t pgtables_bytes; /* PTE page table pages */
454 int map_count; /* number of VMAs */
456 spinlock_t page_table_lock; /* Protects page tables and some
460 * With some kernel config, the current mmap_lock's offset
461 * inside 'mm_struct' is at 0x120, which is very optimal, as
462 * its two hot fields 'count' and 'owner' sit in 2 different
463 * cachelines, and when mmap_lock is highly contended, both
464 * of the 2 fields will be accessed frequently, current layout
465 * will help to reduce cache bouncing.
467 * So please be careful with adding new fields before
468 * mmap_lock, which can easily push the 2 fields into one
471 struct rw_semaphore mmap_lock;
473 struct list_head mmlist; /* List of maybe swapped mm's. These
474 * are globally strung together off
475 * init_mm.mmlist, and are protected
480 unsigned long hiwater_rss; /* High-watermark of RSS usage */
481 unsigned long hiwater_vm; /* High-water virtual memory usage */
483 unsigned long total_vm; /* Total pages mapped */
484 unsigned long locked_vm; /* Pages that have PG_mlocked set */
485 atomic64_t pinned_vm; /* Refcount permanently increased */
486 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
487 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
488 unsigned long stack_vm; /* VM_STACK */
489 unsigned long def_flags;
492 * @write_protect_seq: Locked when any thread is write
493 * protecting pages mapped by this mm to enforce a later COW,
494 * for instance during page table copying for fork().
496 seqcount_t write_protect_seq;
498 spinlock_t arg_lock; /* protect the below fields */
500 unsigned long start_code, end_code, start_data, end_data;
501 unsigned long start_brk, brk, start_stack;
502 unsigned long arg_start, arg_end, env_start, env_end;
504 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
507 * Special counters, in some configurations protected by the
508 * page_table_lock, in other configurations by being atomic.
510 struct mm_rss_stat rss_stat;
512 struct linux_binfmt *binfmt;
514 /* Architecture-specific MM context */
515 mm_context_t context;
517 unsigned long flags; /* Must use atomic bitops to access */
519 struct core_state *core_state; /* coredumping support */
522 spinlock_t ioctx_lock;
523 struct kioctx_table __rcu *ioctx_table;
527 * "owner" points to a task that is regarded as the canonical
528 * user/owner of this mm. All of the following must be true in
529 * order for it to be changed:
531 * current == mm->owner
533 * new_owner->mm == mm
534 * new_owner->alloc_lock is held
536 struct task_struct __rcu *owner;
538 struct user_namespace *user_ns;
540 /* store ref to file /proc/<pid>/exe symlink points to */
541 struct file __rcu *exe_file;
542 #ifdef CONFIG_MMU_NOTIFIER
543 struct mmu_notifier_subscriptions *notifier_subscriptions;
545 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
546 pgtable_t pmd_huge_pte; /* protected by page_table_lock */
548 #ifdef CONFIG_NUMA_BALANCING
550 * numa_next_scan is the next time that the PTEs will be marked
551 * pte_numa. NUMA hinting faults will gather statistics and
552 * migrate pages to new nodes if necessary.
554 unsigned long numa_next_scan;
556 /* Restart point for scanning and setting pte_numa */
557 unsigned long numa_scan_offset;
559 /* numa_scan_seq prevents two threads setting pte_numa */
563 * An operation with batched TLB flushing is going on. Anything
564 * that can move process memory needs to flush the TLB when
565 * moving a PROT_NONE or PROT_NUMA mapped page.
567 atomic_t tlb_flush_pending;
568 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
569 /* See flush_tlb_batched_pending() */
570 bool tlb_flush_batched;
572 struct uprobes_state uprobes_state;
573 #ifdef CONFIG_HUGETLB_PAGE
574 atomic_long_t hugetlb_usage;
576 struct work_struct async_put_work;
578 #ifdef CONFIG_IOMMU_SUPPORT
581 } __randomize_layout;
584 * The mm_cpumask needs to be at the end of mm_struct, because it
585 * is dynamically sized based on nr_cpu_ids.
587 unsigned long cpu_bitmap[];
590 extern struct mm_struct init_mm;
592 /* Pointer magic because the dynamic array size confuses some compilers. */
593 static inline void mm_init_cpumask(struct mm_struct *mm)
595 unsigned long cpu_bitmap = (unsigned long)mm;
597 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap);
598 cpumask_clear((struct cpumask *)cpu_bitmap);
601 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
602 static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
604 return (struct cpumask *)&mm->cpu_bitmap;
608 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
609 unsigned long start, unsigned long end);
610 extern void tlb_finish_mmu(struct mmu_gather *tlb,
611 unsigned long start, unsigned long end);
613 static inline void init_tlb_flush_pending(struct mm_struct *mm)
615 atomic_set(&mm->tlb_flush_pending, 0);
618 static inline void inc_tlb_flush_pending(struct mm_struct *mm)
620 atomic_inc(&mm->tlb_flush_pending);
622 * The only time this value is relevant is when there are indeed pages
623 * to flush. And we'll only flush pages after changing them, which
626 * So the ordering here is:
628 * atomic_inc(&mm->tlb_flush_pending);
635 * mm_tlb_flush_pending();
640 * atomic_dec(&mm->tlb_flush_pending);
642 * Where the increment if constrained by the PTL unlock, it thus
643 * ensures that the increment is visible if the PTE modification is
644 * visible. After all, if there is no PTE modification, nobody cares
645 * about TLB flushes either.
647 * This very much relies on users (mm_tlb_flush_pending() and
648 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
649 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
650 * locks (PPC) the unlock of one doesn't order against the lock of
653 * The decrement is ordered by the flush_tlb_range(), such that
654 * mm_tlb_flush_pending() will not return false unless all flushes have
659 static inline void dec_tlb_flush_pending(struct mm_struct *mm)
662 * See inc_tlb_flush_pending().
664 * This cannot be smp_mb__before_atomic() because smp_mb() simply does
665 * not order against TLB invalidate completion, which is what we need.
667 * Therefore we must rely on tlb_flush_*() to guarantee order.
669 atomic_dec(&mm->tlb_flush_pending);
672 static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
675 * Must be called after having acquired the PTL; orders against that
676 * PTLs release and therefore ensures that if we observe the modified
677 * PTE we must also observe the increment from inc_tlb_flush_pending().
679 * That is, it only guarantees to return true if there is a flush
680 * pending for _this_ PTL.
682 return atomic_read(&mm->tlb_flush_pending);
685 static inline bool mm_tlb_flush_nested(struct mm_struct *mm)
688 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL
689 * for which there is a TLB flush pending in order to guarantee
690 * we've seen both that PTE modification and the increment.
692 * (no requirement on actually still holding the PTL, that is irrelevant)
694 return atomic_read(&mm->tlb_flush_pending) > 1;
700 * typedef vm_fault_t - Return type for page fault handlers.
702 * Page fault handlers return a bitmask of %VM_FAULT values.
704 typedef __bitwise unsigned int vm_fault_t;
707 * enum vm_fault_reason - Page fault handlers return a bitmask of
708 * these values to tell the core VM what happened when handling the
709 * fault. Used to decide whether a process gets delivered SIGBUS or
710 * just gets major/minor fault counters bumped up.
712 * @VM_FAULT_OOM: Out Of Memory
713 * @VM_FAULT_SIGBUS: Bad access
714 * @VM_FAULT_MAJOR: Page read from storage
715 * @VM_FAULT_WRITE: Special case for get_user_pages
716 * @VM_FAULT_HWPOISON: Hit poisoned small page
717 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded
719 * @VM_FAULT_SIGSEGV: segmentation fault
720 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page
721 * @VM_FAULT_LOCKED: ->fault locked the returned page
722 * @VM_FAULT_RETRY: ->fault blocked, must retry
723 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small
724 * @VM_FAULT_DONE_COW: ->fault has fully handled COW
725 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs
726 * fsync() to complete (for synchronous page faults
728 * @VM_FAULT_HINDEX_MASK: mask HINDEX value
731 enum vm_fault_reason {
732 VM_FAULT_OOM = (__force vm_fault_t)0x000001,
733 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002,
734 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004,
735 VM_FAULT_WRITE = (__force vm_fault_t)0x000008,
736 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010,
737 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020,
738 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040,
739 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100,
740 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200,
741 VM_FAULT_RETRY = (__force vm_fault_t)0x000400,
742 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800,
743 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000,
744 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000,
745 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000,
748 /* Encode hstate index for a hwpoisoned large page */
749 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))
750 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf)
752 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \
753 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \
754 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK)
756 #define VM_FAULT_RESULT_TRACE \
757 { VM_FAULT_OOM, "OOM" }, \
758 { VM_FAULT_SIGBUS, "SIGBUS" }, \
759 { VM_FAULT_MAJOR, "MAJOR" }, \
760 { VM_FAULT_WRITE, "WRITE" }, \
761 { VM_FAULT_HWPOISON, "HWPOISON" }, \
762 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \
763 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \
764 { VM_FAULT_NOPAGE, "NOPAGE" }, \
765 { VM_FAULT_LOCKED, "LOCKED" }, \
766 { VM_FAULT_RETRY, "RETRY" }, \
767 { VM_FAULT_FALLBACK, "FALLBACK" }, \
768 { VM_FAULT_DONE_COW, "DONE_COW" }, \
769 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
771 struct vm_special_mapping {
772 const char *name; /* The name, e.g. "[vdso]". */
775 * If .fault is not provided, this points to a
776 * NULL-terminated array of pages that back the special mapping.
778 * This must not be NULL unless .fault is provided.
783 * If non-NULL, then this is called to resolve page faults
784 * on the special mapping. If used, .pages is not checked.
786 vm_fault_t (*fault)(const struct vm_special_mapping *sm,
787 struct vm_area_struct *vma,
788 struct vm_fault *vmf);
790 int (*mremap)(const struct vm_special_mapping *sm,
791 struct vm_area_struct *new_vma);
794 enum tlb_flush_reason {
795 TLB_FLUSH_ON_TASK_SWITCH,
796 TLB_REMOTE_SHOOTDOWN,
798 TLB_LOCAL_MM_SHOOTDOWN,
800 NR_TLB_FLUSH_REASONS,
804 * A swap entry has to fit into a "unsigned long", as the entry is hidden
805 * in the "index" field of the swapper address space.
811 #endif /* _LINUX_MM_TYPES_H */