include/linux/vmalloc.h

   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  * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
  27  * vfree_atomic().
  28  */
  29 #define VM_FLUSH_RESET_PERMS    0x00000100      /* Reset direct map and flush TLB on unmap */
  30
  31 /* bits [20..32] reserved for arch specific ioremap internals */
  32
  33 /*
  34  * Maximum alignment for ioremap() regions.
  35  * Can be overriden by arch-specific value.
  36  */
  37 #ifndef IOREMAP_MAX_ORDER
  38 #define IOREMAP_MAX_ORDER       (7 + PAGE_SHIFT)        /* 128 pages */
  39 #endif
  40
  41 struct vm_struct {
  42         struct vm_struct        *next;
  43         void                    *addr;
  44         unsigned long           size;
  45         unsigned long           flags;
  46         struct page             **pages;
  47         unsigned int            nr_pages;
  48         phys_addr_t             phys_addr;
  49         const void              *caller;
  50 };
  51
  52 struct vmap_area {
  53         unsigned long va_start;
  54         unsigned long va_end;
  55
  56         struct rb_node rb_node;         /* address sorted rbtree */
  57         struct list_head list;          /* address sorted list */
  58
  59         /*
  60          * The following three variables can be packed, because
  61          * a vmap_area object is always one of the three states:
  62          *    1) in "free" tree (root is vmap_area_root)
  63          *    2) in "busy" tree (root is free_vmap_area_root)
  64          *    3) in purge list  (head is vmap_purge_list)
  65          */
  66         union {
  67                 unsigned long subtree_max_size; /* in "free" tree */
  68                 struct vm_struct *vm;           /* in "busy" tree */
  69                 struct llist_node purge_list;   /* in purge list */
  70         };
  71 };
  72
  73 /*
  74  *      Highlevel APIs for driver use
  75  */
  76 extern void vm_unmap_ram(const void *mem, unsigned int count);
  77 extern void *vm_map_ram(struct page **pages, unsigned int count,
  78                                 int node, pgprot_t prot);
  79 extern void vm_unmap_aliases(void);
  80
  81 #ifdef CONFIG_MMU
  82 extern void __init vmalloc_init(void);
  83 extern unsigned long vmalloc_nr_pages(void);
  84 #else
  85 static inline void vmalloc_init(void)
  86 {
  87 }
  88 static inline unsigned long vmalloc_nr_pages(void) { return 0; }
  89 #endif
  90
  91 extern void *vmalloc(unsigned long size);
  92 extern void *vzalloc(unsigned long size);
  93 extern void *vmalloc_user(unsigned long size);
  94 extern void *vmalloc_node(unsigned long size, int node);
  95 extern void *vzalloc_node(unsigned long size, int node);
  96 extern void *vmalloc_exec(unsigned long size);
  97 extern void *vmalloc_32(unsigned long size);
  98 extern void *vmalloc_32_user(unsigned long size);
  99 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);
 100 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 101                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 102                         pgprot_t prot, unsigned long vm_flags, int node,
 103                         const void *caller);
 104 #ifndef CONFIG_MMU
 105 extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags);
 106 static inline void *__vmalloc_node_flags_caller(unsigned long size, int node,
 107                                                 gfp_t flags, void *caller)
 108 {
 109         return __vmalloc_node_flags(size, node, flags);
 110 }
 111 #else
 112 extern void *__vmalloc_node_flags_caller(unsigned long size,
 113                                          int node, gfp_t flags, void *caller);
 114 #endif
 115
 116 extern void vfree(const void *addr);
 117 extern void vfree_atomic(const void *addr);
 118
 119 extern void *vmap(struct page **pages, unsigned int count,
 120                         unsigned long flags, pgprot_t prot);
 121 extern void vunmap(const void *addr);
 122
 123 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
 124                                        unsigned long uaddr, void *kaddr,
 125                                        unsigned long pgoff, unsigned long size);
 126
 127 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 128                                                         unsigned long pgoff);
 129 void vmalloc_sync_mappings(void);
 130 void vmalloc_sync_unmappings(void);
 131
 132 /*
 133  *      Lowlevel-APIs (not for driver use!)
 134  */
 135
 136 static inline size_t get_vm_area_size(const struct vm_struct *area)
 137 {
 138         if (!(area->flags & VM_NO_GUARD))
 139                 /* return actual size without guard page */
 140                 return area->size - PAGE_SIZE;
 141         else
 142                 return area->size;
 143
 144 }
 145
 146 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
 147 extern struct vm_struct *get_vm_area_caller(unsigned long size,
 148                                         unsigned long flags, const void *caller);
 149 extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
 150                                         unsigned long start, unsigned long end);
 151 extern struct vm_struct *__get_vm_area_caller(unsigned long size,
 152                                         unsigned long flags,
 153                                         unsigned long start, unsigned long end,
 154                                         const void *caller);
 155 extern struct vm_struct *remove_vm_area(const void *addr);
 156 extern struct vm_struct *find_vm_area(const void *addr);
 157
 158 extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
 159                         struct page **pages);
 160 #ifdef CONFIG_MMU
 161 extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
 162                                     pgprot_t prot, struct page **pages);
 163 extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
 164 extern void unmap_kernel_range(unsigned long addr, unsigned long size);
 165 static inline void set_vm_flush_reset_perms(void *addr)
 166 {
 167         struct vm_struct *vm = find_vm_area(addr);
 168
 169         if (vm)
 170                 vm->flags |= VM_FLUSH_RESET_PERMS;
 171 }
 172 #else
 173 static inline int
 174 map_kernel_range_noflush(unsigned long start, unsigned long size,
 175                         pgprot_t prot, struct page **pages)
 176 {
 177         return size >> PAGE_SHIFT;
 178 }
 179 static inline void
 180 unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
 181 {
 182 }
 183 static inline void
 184 unmap_kernel_range(unsigned long addr, unsigned long size)
 185 {
 186 }
 187 static inline void set_vm_flush_reset_perms(void *addr)
 188 {
 189 }
 190 #endif
 191
 192 /* Allocate/destroy a 'vmalloc' VM area. */
 193 extern struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes);
 194 extern void free_vm_area(struct vm_struct *area);
 195
 196 /* for /dev/kmem */
 197 extern long vread(char *buf, char *addr, unsigned long count);
 198 extern long vwrite(char *buf, char *addr, unsigned long count);
 199
 200 /*
 201  *      Internals.  Dont't use..
 202  */
 203 extern struct list_head vmap_area_list;
 204 extern __init void vm_area_add_early(struct vm_struct *vm);
 205 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
 206
 207 #ifdef CONFIG_SMP
 208 # ifdef CONFIG_MMU
 209 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 210                                      const size_t *sizes, int nr_vms,
 211                                      size_t align);
 212
 213 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
 214 # else
 215 static inline struct vm_struct **
 216 pcpu_get_vm_areas(const unsigned long *offsets,
 217                 const size_t *sizes, int nr_vms,
 218                 size_t align)
 219 {
 220         return NULL;
 221 }
 222
 223 static inline void
 224 pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 225 {
 226 }
 227 # endif
 228 #endif
 229
 230 #ifdef CONFIG_MMU
 231 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
 232 #else
 233 #define VMALLOC_TOTAL 0UL
 234 #endif
 235
 236 int register_vmap_purge_notifier(struct notifier_block *nb);
 237 int unregister_vmap_purge_notifier(struct notifier_block *nb);
 238
 239 #endif /* _LINUX_VMALLOC_H */