1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_MM_TYPES_TASK_H
3#define _LINUX_MM_TYPES_TASK_H
4
5/*
6 * Here are the definitions of the MM data types that are embedded in 'struct task_struct'.
7 *
8 * (These are defined separately to decouple sched.h from mm_types.h as much as possible.)
9 */
10
11#include <linux/align.h>
12#include <linux/types.h>
13
14#include <asm/page.h>
15
16#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
17#include <asm/tlbbatch.h>
18#endif
19
20#define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8)
21
22/*
23 * When updating this, please also update struct resident_page_types[] in
24 * kernel/fork.c
25 */
26enum {
27 MM_FILEPAGES, /* Resident file mapping pages */
28 MM_ANONPAGES, /* Resident anonymous pages */
29 MM_SWAPENTS, /* Anonymous swap entries */
30 MM_SHMEMPAGES, /* Resident shared memory pages */
31 NR_MM_COUNTERS
32};
33
34struct page;
35
36struct page_frag {
37 struct page *page;
38#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
39 __u32 offset;
40 __u32 size;
41#else
42 __u16 offset;
43 __u16 size;
44#endif
45};
46
47#define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
48#define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
49struct page_frag_cache {
50 /* encoded_page consists of the virtual address, pfmemalloc bit and
51 * order of a page.
52 */
53 unsigned long encoded_page;
54
55 /* we maintain a pagecount bias, so that we dont dirty cache line
56 * containing page->_refcount every time we allocate a fragment.
57 */
58#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) && (BITS_PER_LONG <= 32)
59 __u16 offset;
60 __u16 pagecnt_bias;
61#else
62 __u32 offset;
63 __u32 pagecnt_bias;
64#endif
65};
66
67/* Track pages that require TLB flushes */
68struct tlbflush_unmap_batch {
69#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
70 /*
71 * The arch code makes the following promise: generic code can modify a
72 * PTE, then call arch_tlbbatch_add_pending() (which internally provides
73 * all needed barriers), then call arch_tlbbatch_flush(), and the entries
74 * will be flushed on all CPUs by the time that arch_tlbbatch_flush()
75 * returns.
76 */
77 struct arch_tlbflush_unmap_batch arch;
78
79 /* True if a flush is needed. */
80 bool flush_required;
81
82 /*
83 * If true then the PTE was dirty when unmapped. The entry must be
84 * flushed before IO is initiated or a stale TLB entry potentially
85 * allows an update without redirtying the page.
86 */
87 bool writable;
88#endif
89};
90
91#endif /* _LINUX_MM_TYPES_TASK_H */
92