xref: /linux/include/linux/vmalloc.h (revision 9a6b55ac)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_VMALLOC_H
3 #define _LINUX_VMALLOC_H
4 
5 #include <linux/spinlock.h>
6 #include <linux/init.h>
7 #include <linux/list.h>
8 #include <linux/llist.h>
9 #include <asm/page.h>		/* pgprot_t */
10 #include <linux/rbtree.h>
11 #include <linux/overflow.h>
12 
13 struct vm_area_struct;		/* vma defining user mapping in mm_types.h */
14 struct notifier_block;		/* in notifier.h */
15 
16 /* bits in flags of vmalloc's vm_struct below */
17 #define VM_IOREMAP		0x00000001	/* ioremap() and friends */
18 #define VM_ALLOC		0x00000002	/* vmalloc() */
19 #define VM_MAP			0x00000004	/* vmap()ed pages */
20 #define VM_USERMAP		0x00000008	/* suitable for remap_vmalloc_range */
21 #define VM_DMA_COHERENT		0x00000010	/* dma_alloc_coherent */
22 #define VM_UNINITIALIZED	0x00000020	/* vm_struct is not fully initialized */
23 #define VM_NO_GUARD		0x00000040      /* don't add guard page */
24 #define VM_KASAN		0x00000080      /* has allocated kasan shadow memory */
25 
26 /*
27  * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
28  *
29  * If IS_ENABLED(CONFIG_KASAN_VMALLOC), VM_KASAN is set on a vm_struct after
30  * shadow memory has been mapped. It's used to handle allocation errors so that
31  * we don't try to poision shadow on free if it was never allocated.
32  *
33  * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
34  * determine which allocations need the module shadow freed.
35  */
36 
37 /*
38  * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
39  * vfree_atomic().
40  */
41 #define VM_FLUSH_RESET_PERMS	0x00000100      /* Reset direct map and flush TLB on unmap */
42 
43 /* bits [20..32] reserved for arch specific ioremap internals */
44 
45 /*
46  * Maximum alignment for ioremap() regions.
47  * Can be overriden by arch-specific value.
48  */
49 #ifndef IOREMAP_MAX_ORDER
50 #define IOREMAP_MAX_ORDER	(7 + PAGE_SHIFT)	/* 128 pages */
51 #endif
52 
53 struct vm_struct {
54 	struct vm_struct	*next;
55 	void			*addr;
56 	unsigned long		size;
57 	unsigned long		flags;
58 	struct page		**pages;
59 	unsigned int		nr_pages;
60 	phys_addr_t		phys_addr;
61 	const void		*caller;
62 };
63 
64 struct vmap_area {
65 	unsigned long va_start;
66 	unsigned long va_end;
67 
68 	struct rb_node rb_node;         /* address sorted rbtree */
69 	struct list_head list;          /* address sorted list */
70 
71 	/*
72 	 * The following three variables can be packed, because
73 	 * a vmap_area object is always one of the three states:
74 	 *    1) in "free" tree (root is vmap_area_root)
75 	 *    2) in "busy" tree (root is free_vmap_area_root)
76 	 *    3) in purge list  (head is vmap_purge_list)
77 	 */
78 	union {
79 		unsigned long subtree_max_size; /* in "free" tree */
80 		struct vm_struct *vm;           /* in "busy" tree */
81 		struct llist_node purge_list;   /* in purge list */
82 	};
83 };
84 
85 /*
86  *	Highlevel APIs for driver use
87  */
88 extern void vm_unmap_ram(const void *mem, unsigned int count);
89 extern void *vm_map_ram(struct page **pages, unsigned int count,
90 				int node, pgprot_t prot);
91 extern void vm_unmap_aliases(void);
92 
93 #ifdef CONFIG_MMU
94 extern void __init vmalloc_init(void);
95 extern unsigned long vmalloc_nr_pages(void);
96 #else
97 static inline void vmalloc_init(void)
98 {
99 }
100 static inline unsigned long vmalloc_nr_pages(void) { return 0; }
101 #endif
102 
103 extern void *vmalloc(unsigned long size);
104 extern void *vzalloc(unsigned long size);
105 extern void *vmalloc_user(unsigned long size);
106 extern void *vmalloc_node(unsigned long size, int node);
107 extern void *vzalloc_node(unsigned long size, int node);
108 extern void *vmalloc_user_node_flags(unsigned long size, int node, gfp_t flags);
109 extern void *vmalloc_exec(unsigned long size);
110 extern void *vmalloc_32(unsigned long size);
111 extern void *vmalloc_32_user(unsigned long size);
112 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);
113 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
114 			unsigned long start, unsigned long end, gfp_t gfp_mask,
115 			pgprot_t prot, unsigned long vm_flags, int node,
116 			const void *caller);
117 #ifndef CONFIG_MMU
118 extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags);
119 static inline void *__vmalloc_node_flags_caller(unsigned long size, int node,
120 						gfp_t flags, void *caller)
121 {
122 	return __vmalloc_node_flags(size, node, flags);
123 }
124 #else
125 extern void *__vmalloc_node_flags_caller(unsigned long size,
126 					 int node, gfp_t flags, void *caller);
127 #endif
128 
129 extern void vfree(const void *addr);
130 extern void vfree_atomic(const void *addr);
131 
132 extern void *vmap(struct page **pages, unsigned int count,
133 			unsigned long flags, pgprot_t prot);
134 extern void vunmap(const void *addr);
135 
136 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
137 				       unsigned long uaddr, void *kaddr,
138 				       unsigned long size);
139 
140 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
141 							unsigned long pgoff);
142 void vmalloc_sync_all(void);
143 
144 /*
145  *	Lowlevel-APIs (not for driver use!)
146  */
147 
148 static inline size_t get_vm_area_size(const struct vm_struct *area)
149 {
150 	if (!(area->flags & VM_NO_GUARD))
151 		/* return actual size without guard page */
152 		return area->size - PAGE_SIZE;
153 	else
154 		return area->size;
155 
156 }
157 
158 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
159 extern struct vm_struct *get_vm_area_caller(unsigned long size,
160 					unsigned long flags, const void *caller);
161 extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
162 					unsigned long start, unsigned long end);
163 extern struct vm_struct *__get_vm_area_caller(unsigned long size,
164 					unsigned long flags,
165 					unsigned long start, unsigned long end,
166 					const void *caller);
167 extern struct vm_struct *remove_vm_area(const void *addr);
168 extern struct vm_struct *find_vm_area(const void *addr);
169 
170 extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
171 			struct page **pages);
172 #ifdef CONFIG_MMU
173 extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
174 				    pgprot_t prot, struct page **pages);
175 extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
176 extern void unmap_kernel_range(unsigned long addr, unsigned long size);
177 static inline void set_vm_flush_reset_perms(void *addr)
178 {
179 	struct vm_struct *vm = find_vm_area(addr);
180 
181 	if (vm)
182 		vm->flags |= VM_FLUSH_RESET_PERMS;
183 }
184 #else
185 static inline int
186 map_kernel_range_noflush(unsigned long start, unsigned long size,
187 			pgprot_t prot, struct page **pages)
188 {
189 	return size >> PAGE_SHIFT;
190 }
191 static inline void
192 unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
193 {
194 }
195 static inline void
196 unmap_kernel_range(unsigned long addr, unsigned long size)
197 {
198 }
199 static inline void set_vm_flush_reset_perms(void *addr)
200 {
201 }
202 #endif
203 
204 /* Allocate/destroy a 'vmalloc' VM area. */
205 extern struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes);
206 extern void free_vm_area(struct vm_struct *area);
207 
208 /* for /dev/kmem */
209 extern long vread(char *buf, char *addr, unsigned long count);
210 extern long vwrite(char *buf, char *addr, unsigned long count);
211 
212 /*
213  *	Internals.  Dont't use..
214  */
215 extern struct list_head vmap_area_list;
216 extern __init void vm_area_add_early(struct vm_struct *vm);
217 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
218 
219 #ifdef CONFIG_SMP
220 # ifdef CONFIG_MMU
221 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
222 				     const size_t *sizes, int nr_vms,
223 				     size_t align);
224 
225 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
226 # else
227 static inline struct vm_struct **
228 pcpu_get_vm_areas(const unsigned long *offsets,
229 		const size_t *sizes, int nr_vms,
230 		size_t align)
231 {
232 	return NULL;
233 }
234 
235 static inline void
236 pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
237 {
238 }
239 # endif
240 #endif
241 
242 #ifdef CONFIG_MMU
243 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
244 #else
245 #define VMALLOC_TOTAL 0UL
246 #endif
247 
248 int register_vmap_purge_notifier(struct notifier_block *nb);
249 int unregister_vmap_purge_notifier(struct notifier_block *nb);
250 
251 #endif /* _LINUX_VMALLOC_H */
252