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 /*
  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 */