1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * page allocation tagging
4 */
5 #ifndef _LINUX_PGALLOC_TAG_H
6 #define _LINUX_PGALLOC_TAG_H
7
8 #include <linux/alloc_tag.h>
9
10 #ifdef CONFIG_MEM_ALLOC_PROFILING
11
12 #include <linux/page_ext.h>
13
14 extern struct page_ext_operations page_alloc_tagging_ops;
15 extern unsigned long alloc_tag_ref_mask;
16 extern int alloc_tag_ref_offs;
17 extern struct alloc_tag_kernel_section kernel_tags;
18
19 DECLARE_STATIC_KEY_FALSE(mem_profiling_compressed);
20
21 typedef u16 pgalloc_tag_idx;
22
23 union pgtag_ref_handle {
24 union codetag_ref *ref; /* reference in page extension */
25 struct page *page; /* reference in page flags */
26 };
27
28 /* Reserved indexes */
29 #define CODETAG_ID_NULL 0
30 #define CODETAG_ID_EMPTY 1
31 #define CODETAG_ID_FIRST 2
32
33 #ifdef CONFIG_MODULES
34
35 extern struct alloc_tag_module_section module_tags;
36
module_idx_to_tag(pgalloc_tag_idx idx)37 static inline struct alloc_tag *module_idx_to_tag(pgalloc_tag_idx idx)
38 {
39 return &module_tags.first_tag[idx - kernel_tags.count];
40 }
41
module_tag_to_idx(struct alloc_tag * tag)42 static inline pgalloc_tag_idx module_tag_to_idx(struct alloc_tag *tag)
43 {
44 return CODETAG_ID_FIRST + kernel_tags.count + (tag - module_tags.first_tag);
45 }
46
47 #else /* CONFIG_MODULES */
48
module_idx_to_tag(pgalloc_tag_idx idx)49 static inline struct alloc_tag *module_idx_to_tag(pgalloc_tag_idx idx)
50 {
51 pr_warn("invalid page tag reference %lu\n", (unsigned long)idx);
52 return NULL;
53 }
54
module_tag_to_idx(struct alloc_tag * tag)55 static inline pgalloc_tag_idx module_tag_to_idx(struct alloc_tag *tag)
56 {
57 pr_warn("invalid page tag 0x%lx\n", (unsigned long)tag);
58 return CODETAG_ID_NULL;
59 }
60
61 #endif /* CONFIG_MODULES */
62
idx_to_ref(pgalloc_tag_idx idx,union codetag_ref * ref)63 static inline void idx_to_ref(pgalloc_tag_idx idx, union codetag_ref *ref)
64 {
65 switch (idx) {
66 case (CODETAG_ID_NULL):
67 ref->ct = NULL;
68 break;
69 case (CODETAG_ID_EMPTY):
70 set_codetag_empty(ref);
71 break;
72 default:
73 idx -= CODETAG_ID_FIRST;
74 ref->ct = idx < kernel_tags.count ?
75 &kernel_tags.first_tag[idx].ct :
76 &module_idx_to_tag(idx)->ct;
77 break;
78 }
79 }
80
ref_to_idx(union codetag_ref * ref)81 static inline pgalloc_tag_idx ref_to_idx(union codetag_ref *ref)
82 {
83 struct alloc_tag *tag;
84
85 if (!ref->ct)
86 return CODETAG_ID_NULL;
87
88 if (is_codetag_empty(ref))
89 return CODETAG_ID_EMPTY;
90
91 tag = ct_to_alloc_tag(ref->ct);
92 if (tag >= kernel_tags.first_tag && tag < kernel_tags.first_tag + kernel_tags.count)
93 return CODETAG_ID_FIRST + (tag - kernel_tags.first_tag);
94
95 return module_tag_to_idx(tag);
96 }
97
98
99
100 /* Should be called only if mem_alloc_profiling_enabled() */
get_page_tag_ref(struct page * page,union codetag_ref * ref,union pgtag_ref_handle * handle)101 static inline bool get_page_tag_ref(struct page *page, union codetag_ref *ref,
102 union pgtag_ref_handle *handle)
103 {
104 if (!page)
105 return false;
106
107 if (static_key_enabled(&mem_profiling_compressed)) {
108 pgalloc_tag_idx idx;
109
110 idx = (page->flags.f >> alloc_tag_ref_offs) &
111 alloc_tag_ref_mask;
112 idx_to_ref(idx, ref);
113 handle->page = page;
114 } else {
115 struct page_ext *page_ext;
116 union codetag_ref *tmp;
117
118 page_ext = page_ext_get(page);
119 if (!page_ext)
120 return false;
121
122 tmp = (union codetag_ref *)page_ext_data(page_ext, &page_alloc_tagging_ops);
123 ref->ct = tmp->ct;
124 handle->ref = tmp;
125 }
126
127 return true;
128 }
129
put_page_tag_ref(union pgtag_ref_handle handle)130 static inline void put_page_tag_ref(union pgtag_ref_handle handle)
131 {
132 if (WARN_ON(!handle.ref))
133 return;
134
135 if (!static_key_enabled(&mem_profiling_compressed))
136 page_ext_put((void *)handle.ref - page_alloc_tagging_ops.offset);
137 }
138
update_page_tag_ref(union pgtag_ref_handle handle,union codetag_ref * ref)139 static inline void update_page_tag_ref(union pgtag_ref_handle handle, union codetag_ref *ref)
140 {
141 if (static_key_enabled(&mem_profiling_compressed)) {
142 struct page *page = handle.page;
143 unsigned long old_flags;
144 unsigned long flags;
145 unsigned long idx;
146
147 if (WARN_ON(!page || !ref))
148 return;
149
150 idx = (unsigned long)ref_to_idx(ref);
151 idx = (idx & alloc_tag_ref_mask) << alloc_tag_ref_offs;
152 do {
153 old_flags = READ_ONCE(page->flags.f);
154 flags = old_flags;
155 flags &= ~(alloc_tag_ref_mask << alloc_tag_ref_offs);
156 flags |= idx;
157 } while (unlikely(!try_cmpxchg(&page->flags.f, &old_flags, flags)));
158 } else {
159 if (WARN_ON(!handle.ref || !ref))
160 return;
161
162 handle.ref->ct = ref->ct;
163 }
164 }
165
166 /* Should be called only if mem_alloc_profiling_enabled() */
167 void __clear_page_tag_ref(struct page *page);
168
clear_page_tag_ref(struct page * page)169 static inline void clear_page_tag_ref(struct page *page)
170 {
171 if (mem_alloc_profiling_enabled())
172 __clear_page_tag_ref(page);
173 }
174
175 /* Should be called only if mem_alloc_profiling_enabled() */
__pgalloc_tag_get(struct page * page)176 static inline struct alloc_tag *__pgalloc_tag_get(struct page *page)
177 {
178 struct alloc_tag *tag = NULL;
179 union pgtag_ref_handle handle;
180 union codetag_ref ref;
181
182 if (get_page_tag_ref(page, &ref, &handle)) {
183 alloc_tag_sub_check(&ref);
184 if (ref.ct)
185 tag = ct_to_alloc_tag(ref.ct);
186 put_page_tag_ref(handle);
187 }
188
189 return tag;
190 }
191
pgalloc_tag_get(struct page * page)192 static inline struct alloc_tag *pgalloc_tag_get(struct page *page)
193 {
194 if (mem_alloc_profiling_enabled())
195 return __pgalloc_tag_get(page);
196 return NULL;
197 }
198
199 void pgalloc_tag_split(struct folio *folio, int old_order, int new_order);
200 void pgalloc_tag_swap(struct folio *new, struct folio *old);
201
202 void __init alloc_tag_sec_init(void);
203
204 #else /* CONFIG_MEM_ALLOC_PROFILING */
205
clear_page_tag_ref(struct page * page)206 static inline void clear_page_tag_ref(struct page *page) {}
alloc_tag_sec_init(void)207 static inline void alloc_tag_sec_init(void) {}
pgalloc_tag_split(struct folio * folio,int old_order,int new_order)208 static inline void pgalloc_tag_split(struct folio *folio, int old_order, int new_order) {}
pgalloc_tag_swap(struct folio * new,struct folio * old)209 static inline void pgalloc_tag_swap(struct folio *new, struct folio *old) {}
pgalloc_tag_get(struct page * page)210 static inline struct alloc_tag *pgalloc_tag_get(struct page *page) { return NULL; }
211
212 #endif /* CONFIG_MEM_ALLOC_PROFILING */
213
214 #endif /* _LINUX_PGALLOC_TAG_H */
215