1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * NUMA memory policies for Linux.
4 * Copyright 2003,2004 Andi Kleen SuSE Labs
5 */
6#ifndef _LINUX_MEMPOLICY_H
7#define _LINUX_MEMPOLICY_H 1
8
9
10#include <linux/mmzone.h>
11#include <linux/dax.h>
12#include <linux/slab.h>
13#include <linux/rbtree.h>
14#include <linux/spinlock.h>
15#include <linux/nodemask.h>
16#include <linux/pagemap.h>
17#include <uapi/linux/mempolicy.h>
18
19struct mm_struct;
20
21#ifdef CONFIG_NUMA
22
23/*
24 * Describe a memory policy.
25 *
26 * A mempolicy can be either associated with a process or with a VMA.
27 * For VMA related allocations the VMA policy is preferred, otherwise
28 * the process policy is used. Interrupts ignore the memory policy
29 * of the current process.
30 *
31 * Locking policy for interlave:
32 * In process context there is no locking because only the process accesses
33 * its own state. All vma manipulation is somewhat protected by a down_read on
34 * mmap_sem.
35 *
36 * Freeing policy:
37 * Mempolicy objects are reference counted. A mempolicy will be freed when
38 * mpol_put() decrements the reference count to zero.
39 *
40 * Duplicating policy objects:
41 * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
42 * to the new storage. The reference count of the new object is initialized
43 * to 1, representing the caller of mpol_dup().
44 */
45struct mempolicy {
46 atomic_t refcnt;
47 unsigned short mode; /* See MPOL_* above */
48 unsigned short flags; /* See set_mempolicy() MPOL_F_* above */
49 union {
50 short preferred_node; /* preferred */
51 nodemask_t nodes; /* interleave/bind */
52 /* undefined for default */
53 } v;
54 union {
55 nodemask_t cpuset_mems_allowed; /* relative to these nodes */
56 nodemask_t user_nodemask; /* nodemask passed by user */
57 } w;
58};
59
60/*
61 * Support for managing mempolicy data objects (clone, copy, destroy)
62 * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
63 */
64
65extern void __mpol_put(struct mempolicy *pol);
66static inline void mpol_put(struct mempolicy *pol)
67{
68 if (pol)
69 __mpol_put(pol);
70}
71
72/*
73 * Does mempolicy pol need explicit unref after use?
74 * Currently only needed for shared policies.
75 */
76static inline int mpol_needs_cond_ref(struct mempolicy *pol)
77{
78 return (pol && (pol->flags & MPOL_F_SHARED));
79}
80
81static inline void mpol_cond_put(struct mempolicy *pol)
82{
83 if (mpol_needs_cond_ref(pol))
84 __mpol_put(pol);
85}
86
87extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
88static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
89{
90 if (pol)
91 pol = __mpol_dup(pol);
92 return pol;
93}
94
95#define vma_policy(vma) ((vma)->vm_policy)
96
97static inline void mpol_get(struct mempolicy *pol)
98{
99 if (pol)
100 atomic_inc(&pol->refcnt);
101}
102
103extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
104static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
105{
106 if (a == b)
107 return true;
108 return __mpol_equal(a, b);
109}
110
111/*
112 * Tree of shared policies for a shared memory region.
113 * Maintain the policies in a pseudo mm that contains vmas. The vmas
114 * carry the policy. As a special twist the pseudo mm is indexed in pages, not
115 * bytes, so that we can work with shared memory segments bigger than
116 * unsigned long.
117 */
118
119struct sp_node {
120 struct rb_node nd;
121 unsigned long start, end;
122 struct mempolicy *policy;
123};
124
125struct shared_policy {
126 struct rb_root root;
127 rwlock_t lock;
128};
129
130int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
131void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
132int mpol_set_shared_policy(struct shared_policy *info,
133 struct vm_area_struct *vma,
134 struct mempolicy *new);
135void mpol_free_shared_policy(struct shared_policy *p);
136struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
137 unsigned long idx);
138
139struct mempolicy *get_task_policy(struct task_struct *p);
140struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
141 unsigned long addr);
142bool vma_policy_mof(struct vm_area_struct *vma);
143
144extern void numa_default_policy(void);
145extern void numa_policy_init(void);
146extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new);
147extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
148
149extern int huge_node(struct vm_area_struct *vma,
150 unsigned long addr, gfp_t gfp_flags,
151 struct mempolicy **mpol, nodemask_t **nodemask);
152extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
153extern bool mempolicy_nodemask_intersects(struct task_struct *tsk,
154 const nodemask_t *mask);
155extern unsigned int mempolicy_slab_node(void);
156
157extern enum zone_type policy_zone;
158
159static inline void check_highest_zone(enum zone_type k)
160{
161 if (k > policy_zone && k != ZONE_MOVABLE)
162 policy_zone = k;
163}
164
165int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
166 const nodemask_t *to, int flags);
167
168
169#ifdef CONFIG_TMPFS
170extern int mpol_parse_str(char *str, struct mempolicy **mpol);
171#endif
172
173extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
174
175/* Check if a vma is migratable */
176static inline bool vma_migratable(struct vm_area_struct *vma)
177{
178 if (vma->vm_flags & (VM_IO | VM_PFNMAP))
179 return false;
180
181 /*
182 * DAX device mappings require predictable access latency, so avoid
183 * incurring periodic faults.
184 */
185 if (vma_is_dax(vma))
186 return false;
187
188#ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
189 if (vma->vm_flags & VM_HUGETLB)
190 return false;
191#endif
192
193 /*
194 * Migration allocates pages in the highest zone. If we cannot
195 * do so then migration (at least from node to node) is not
196 * possible.
197 */
198 if (vma->vm_file &&
199 gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
200 < policy_zone)
201 return false;
202 return true;
203}
204
205extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
206extern void mpol_put_task_policy(struct task_struct *);
207
208#else
209
210struct mempolicy {};
211
212static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
213{
214 return true;
215}
216
217static inline void mpol_put(struct mempolicy *p)
218{
219}
220
221static inline void mpol_cond_put(struct mempolicy *pol)
222{
223}
224
225static inline void mpol_get(struct mempolicy *pol)
226{
227}
228
229struct shared_policy {};
230
231static inline void mpol_shared_policy_init(struct shared_policy *sp,
232 struct mempolicy *mpol)
233{
234}
235
236static inline void mpol_free_shared_policy(struct shared_policy *p)
237{
238}
239
240static inline struct mempolicy *
241mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
242{
243 return NULL;
244}
245
246#define vma_policy(vma) NULL
247
248static inline int
249vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
250{
251 return 0;
252}
253
254static inline void numa_policy_init(void)
255{
256}
257
258static inline void numa_default_policy(void)
259{
260}
261
262static inline void mpol_rebind_task(struct task_struct *tsk,
263 const nodemask_t *new)
264{
265}
266
267static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
268{
269}
270
271static inline int huge_node(struct vm_area_struct *vma,
272 unsigned long addr, gfp_t gfp_flags,
273 struct mempolicy **mpol, nodemask_t **nodemask)
274{
275 *mpol = NULL;
276 *nodemask = NULL;
277 return 0;
278}
279
280static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
281{
282 return false;
283}
284
285static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
286 const nodemask_t *to, int flags)
287{
288 return 0;
289}
290
291static inline void check_highest_zone(int k)
292{
293}
294
295#ifdef CONFIG_TMPFS
296static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
297{
298 return 1; /* error */
299}
300#endif
301
302static inline int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
303 unsigned long address)
304{
305 return -1; /* no node preference */
306}
307
308static inline void mpol_put_task_policy(struct task_struct *task)
309{
310}
311#endif /* CONFIG_NUMA */
312#endif
313