xref: /linux-6.15/include/linux/vmalloc.h (revision 9ca4efec)
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_MAP_PUT_PAGES	0x00000100	/* put pages and free array in vfree */
28 
29 /*
30  * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
31  *
32  * If IS_ENABLED(CONFIG_KASAN_VMALLOC), VM_KASAN is set on a vm_struct after
33  * shadow memory has been mapped. It's used to handle allocation errors so that
34  * we don't try to poision shadow on free if it was never allocated.
35  *
36  * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
37  * determine which allocations need the module shadow freed.
38  */
39 
40 /*
41  * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
42  * vfree_atomic().
43  */
44 #define VM_FLUSH_RESET_PERMS	0x00000100      /* Reset direct map and flush TLB on unmap */
45 
46 /* bits [20..32] reserved for arch specific ioremap internals */
47 
48 /*
49  * Maximum alignment for ioremap() regions.
50  * Can be overriden by arch-specific value.
51  */
52 #ifndef IOREMAP_MAX_ORDER
53 #define IOREMAP_MAX_ORDER	(7 + PAGE_SHIFT)	/* 128 pages */
54 #endif
55 
56 struct vm_struct {
57 	struct vm_struct	*next;
58 	void			*addr;
59 	unsigned long		size;
60 	unsigned long		flags;
61 	struct page		**pages;
62 	unsigned int		nr_pages;
63 	phys_addr_t		phys_addr;
64 	const void		*caller;
65 };
66 
67 struct vmap_area {
68 	unsigned long va_start;
69 	unsigned long va_end;
70 
71 	struct rb_node rb_node;         /* address sorted rbtree */
72 	struct list_head list;          /* address sorted list */
73 
74 	/*
75 	 * The following two variables can be packed, because
76 	 * a vmap_area object can be either:
77 	 *    1) in "free" tree (root is vmap_area_root)
78 	 *    2) or "busy" tree (root is free_vmap_area_root)
79 	 */
80 	union {
81 		unsigned long subtree_max_size; /* in "free" tree */
82 		struct vm_struct *vm;           /* in "busy" tree */
83 	};
84 };
85 
86 /*
87  *	Highlevel APIs for driver use
88  */
89 extern void vm_unmap_ram(const void *mem, unsigned int count);
90 extern void *vm_map_ram(struct page **pages, unsigned int count, int node);
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_32(unsigned long size);
109 extern void *vmalloc_32_user(unsigned long size);
110 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask);
111 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
112 			unsigned long start, unsigned long end, gfp_t gfp_mask,
113 			pgprot_t prot, unsigned long vm_flags, int node,
114 			const void *caller);
115 void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
116 		int node, const void *caller);
117 
118 extern void vfree(const void *addr);
119 extern void vfree_atomic(const void *addr);
120 
121 extern void *vmap(struct page **pages, unsigned int count,
122 			unsigned long flags, pgprot_t prot);
123 void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot);
124 extern void vunmap(const void *addr);
125 
126 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
127 				       unsigned long uaddr, void *kaddr,
128 				       unsigned long pgoff, unsigned long size);
129 
130 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
131 							unsigned long pgoff);
132 
133 /*
134  * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values
135  * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings()
136  * needs to be called.
137  */
138 #ifndef ARCH_PAGE_TABLE_SYNC_MASK
139 #define ARCH_PAGE_TABLE_SYNC_MASK 0
140 #endif
141 
142 /*
143  * There is no default implementation for arch_sync_kernel_mappings(). It is
144  * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK
145  * is 0.
146  */
147 void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
148 
149 /*
150  *	Lowlevel-APIs (not for driver use!)
151  */
152 
153 static inline size_t get_vm_area_size(const struct vm_struct *area)
154 {
155 	if (!(area->flags & VM_NO_GUARD))
156 		/* return actual size without guard page */
157 		return area->size - PAGE_SIZE;
158 	else
159 		return area->size;
160 
161 }
162 
163 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
164 extern struct vm_struct *get_vm_area_caller(unsigned long size,
165 					unsigned long flags, const void *caller);
166 extern struct vm_struct *__get_vm_area_caller(unsigned long size,
167 					unsigned long flags,
168 					unsigned long start, unsigned long end,
169 					const void *caller);
170 void free_vm_area(struct vm_struct *area);
171 extern struct vm_struct *remove_vm_area(const void *addr);
172 extern struct vm_struct *find_vm_area(const void *addr);
173 
174 #ifdef CONFIG_MMU
175 extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
176 				    pgprot_t prot, struct page **pages);
177 int map_kernel_range(unsigned long start, unsigned long size, pgprot_t prot,
178 		struct page **pages);
179 extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
180 extern void unmap_kernel_range(unsigned long addr, unsigned long size);
181 static inline void set_vm_flush_reset_perms(void *addr)
182 {
183 	struct vm_struct *vm = find_vm_area(addr);
184 
185 	if (vm)
186 		vm->flags |= VM_FLUSH_RESET_PERMS;
187 }
188 #else
189 static inline int
190 map_kernel_range_noflush(unsigned long start, unsigned long size,
191 			pgprot_t prot, struct page **pages)
192 {
193 	return size >> PAGE_SHIFT;
194 }
195 #define map_kernel_range map_kernel_range_noflush
196 static inline void
197 unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
198 {
199 }
200 #define unmap_kernel_range unmap_kernel_range_noflush
201 static inline void set_vm_flush_reset_perms(void *addr)
202 {
203 }
204 #endif
205 
206 /* for /dev/kmem */
207 extern long vread(char *buf, char *addr, unsigned long count);
208 extern long vwrite(char *buf, char *addr, unsigned long count);
209 
210 /*
211  *	Internals.  Dont't use..
212  */
213 extern struct list_head vmap_area_list;
214 extern __init void vm_area_add_early(struct vm_struct *vm);
215 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
216 
217 #ifdef CONFIG_SMP
218 # ifdef CONFIG_MMU
219 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
220 				     const size_t *sizes, int nr_vms,
221 				     size_t align);
222 
223 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
224 # else
225 static inline struct vm_struct **
226 pcpu_get_vm_areas(const unsigned long *offsets,
227 		const size_t *sizes, int nr_vms,
228 		size_t align)
229 {
230 	return NULL;
231 }
232 
233 static inline void
234 pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
235 {
236 }
237 # endif
238 #endif
239 
240 #ifdef CONFIG_MMU
241 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
242 #else
243 #define VMALLOC_TOTAL 0UL
244 #endif
245 
246 int register_vmap_purge_notifier(struct notifier_block *nb);
247 int unregister_vmap_purge_notifier(struct notifier_block *nb);
248 
249 #endif /* _LINUX_VMALLOC_H */
250