xref: /linux-6.15/include/linux/vmalloc.h (revision eef8abda)
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 #include <asm/vmalloc.h>
14 
15 struct vm_area_struct;		/* vma defining user mapping in mm_types.h */
16 struct notifier_block;		/* in notifier.h */
17 
18 /* bits in flags of vmalloc's vm_struct below */
19 #define VM_IOREMAP		0x00000001	/* ioremap() and friends */
20 #define VM_ALLOC		0x00000002	/* vmalloc() */
21 #define VM_MAP			0x00000004	/* vmap()ed pages */
22 #define VM_USERMAP		0x00000008	/* suitable for remap_vmalloc_range */
23 #define VM_DMA_COHERENT		0x00000010	/* dma_alloc_coherent */
24 #define VM_UNINITIALIZED	0x00000020	/* vm_struct is not fully initialized */
25 #define VM_NO_GUARD		0x00000040      /* don't add guard page */
26 #define VM_KASAN		0x00000080      /* has allocated kasan shadow memory */
27 #define VM_FLUSH_RESET_PERMS	0x00000100	/* reset direct map and flush TLB on unmap, can't be freed in atomic context */
28 #define VM_MAP_PUT_PAGES	0x00000200	/* put pages and free array in vfree */
29 
30 /*
31  * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
32  *
33  * If IS_ENABLED(CONFIG_KASAN_VMALLOC), VM_KASAN is set on a vm_struct after
34  * shadow memory has been mapped. It's used to handle allocation errors so that
35  * we don't try to poision shadow on free if it was never allocated.
36  *
37  * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
38  * determine which allocations need the module shadow freed.
39  */
40 
41 /* bits [20..32] reserved for arch specific ioremap internals */
42 
43 /*
44  * Maximum alignment for ioremap() regions.
45  * Can be overriden by arch-specific value.
46  */
47 #ifndef IOREMAP_MAX_ORDER
48 #define IOREMAP_MAX_ORDER	(7 + PAGE_SHIFT)	/* 128 pages */
49 #endif
50 
51 struct vm_struct {
52 	struct vm_struct	*next;
53 	void			*addr;
54 	unsigned long		size;
55 	unsigned long		flags;
56 	struct page		**pages;
57 	unsigned int		nr_pages;
58 	phys_addr_t		phys_addr;
59 	const void		*caller;
60 };
61 
62 struct vmap_area {
63 	unsigned long va_start;
64 	unsigned long va_end;
65 
66 	struct rb_node rb_node;         /* address sorted rbtree */
67 	struct list_head list;          /* address sorted list */
68 
69 	/*
70 	 * The following two variables can be packed, because
71 	 * a vmap_area object can be either:
72 	 *    1) in "free" tree (root is vmap_area_root)
73 	 *    2) or "busy" tree (root is free_vmap_area_root)
74 	 */
75 	union {
76 		unsigned long subtree_max_size; /* in "free" tree */
77 		struct vm_struct *vm;           /* in "busy" tree */
78 	};
79 };
80 
81 /*
82  *	Highlevel APIs for driver use
83  */
84 extern void vm_unmap_ram(const void *mem, unsigned int count);
85 extern void *vm_map_ram(struct page **pages, unsigned int count, int node);
86 extern void vm_unmap_aliases(void);
87 
88 #ifdef CONFIG_MMU
89 extern void __init vmalloc_init(void);
90 extern unsigned long vmalloc_nr_pages(void);
91 #else
92 static inline void vmalloc_init(void)
93 {
94 }
95 static inline unsigned long vmalloc_nr_pages(void) { return 0; }
96 #endif
97 
98 extern void *vmalloc(unsigned long size);
99 extern void *vzalloc(unsigned long size);
100 extern void *vmalloc_user(unsigned long size);
101 extern void *vmalloc_node(unsigned long size, int node);
102 extern void *vzalloc_node(unsigned long size, int node);
103 extern void *vmalloc_32(unsigned long size);
104 extern void *vmalloc_32_user(unsigned long size);
105 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask);
106 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
107 			unsigned long start, unsigned long end, gfp_t gfp_mask,
108 			pgprot_t prot, unsigned long vm_flags, int node,
109 			const void *caller);
110 void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
111 		int node, const void *caller);
112 
113 extern void vfree(const void *addr);
114 extern void vfree_atomic(const void *addr);
115 
116 extern void *vmap(struct page **pages, unsigned int count,
117 			unsigned long flags, pgprot_t prot);
118 void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot);
119 extern void vunmap(const void *addr);
120 
121 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
122 				       unsigned long uaddr, void *kaddr,
123 				       unsigned long pgoff, unsigned long size);
124 
125 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
126 							unsigned long pgoff);
127 
128 /*
129  * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values
130  * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings()
131  * needs to be called.
132  */
133 #ifndef ARCH_PAGE_TABLE_SYNC_MASK
134 #define ARCH_PAGE_TABLE_SYNC_MASK 0
135 #endif
136 
137 /*
138  * There is no default implementation for arch_sync_kernel_mappings(). It is
139  * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK
140  * is 0.
141  */
142 void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
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_caller(unsigned long size,
162 					unsigned long flags,
163 					unsigned long start, unsigned long end,
164 					const void *caller);
165 void free_vm_area(struct vm_struct *area);
166 extern struct vm_struct *remove_vm_area(const void *addr);
167 extern struct vm_struct *find_vm_area(const void *addr);
168 
169 #ifdef CONFIG_MMU
170 extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
171 				    pgprot_t prot, struct page **pages);
172 int map_kernel_range(unsigned long start, unsigned long size, pgprot_t prot,
173 		struct page **pages);
174 extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
175 extern void unmap_kernel_range(unsigned long addr, unsigned long size);
176 static inline void set_vm_flush_reset_perms(void *addr)
177 {
178 	struct vm_struct *vm = find_vm_area(addr);
179 
180 	if (vm)
181 		vm->flags |= VM_FLUSH_RESET_PERMS;
182 }
183 #else
184 static inline int
185 map_kernel_range_noflush(unsigned long start, unsigned long size,
186 			pgprot_t prot, struct page **pages)
187 {
188 	return size >> PAGE_SHIFT;
189 }
190 #define map_kernel_range map_kernel_range_noflush
191 static inline void
192 unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
193 {
194 }
195 #define unmap_kernel_range unmap_kernel_range_noflush
196 static inline void set_vm_flush_reset_perms(void *addr)
197 {
198 }
199 #endif
200 
201 /* for /dev/kmem */
202 extern long vread(char *buf, char *addr, unsigned long count);
203 extern long vwrite(char *buf, char *addr, unsigned long count);
204 
205 /*
206  *	Internals.  Dont't use..
207  */
208 extern struct list_head vmap_area_list;
209 extern __init void vm_area_add_early(struct vm_struct *vm);
210 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
211 
212 #ifdef CONFIG_SMP
213 # ifdef CONFIG_MMU
214 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
215 				     const size_t *sizes, int nr_vms,
216 				     size_t align);
217 
218 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
219 # else
220 static inline struct vm_struct **
221 pcpu_get_vm_areas(const unsigned long *offsets,
222 		const size_t *sizes, int nr_vms,
223 		size_t align)
224 {
225 	return NULL;
226 }
227 
228 static inline void
229 pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
230 {
231 }
232 # endif
233 #endif
234 
235 #ifdef CONFIG_MMU
236 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
237 #else
238 #define VMALLOC_TOTAL 0UL
239 #endif
240 
241 int register_vmap_purge_notifier(struct notifier_block *nb);
242 int unregister_vmap_purge_notifier(struct notifier_block *nb);
243 
244 #ifdef CONFIG_MMU
245 bool vmalloc_dump_obj(void *object);
246 #else
247 static inline bool vmalloc_dump_obj(void *object) { return false; }
248 #endif
249 
250 #endif /* _LINUX_VMALLOC_H */
251