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 #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
  28 /*
  29  * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
  30  *
  31  * If IS_ENABLED(CONFIG_KASAN_VMALLOC), VM_KASAN is set on a vm_struct after
  32  * shadow memory has been mapped. It's used to handle allocation errors so that
  33  * we don't try to poision shadow on free if it was never allocated.
  34  *
  35  * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
  36  * determine which allocations need the module shadow freed.
  37  */
  38
  39 /*
  40  * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
  41  * vfree_atomic().
  42  */
  43 #define VM_FLUSH_RESET_PERMS    0x00000100      /* Reset direct map and flush TLB on unmap */
  44
  45 /* bits [20..32] reserved for arch specific ioremap internals */
  46
  47 /*
  48  * Maximum alignment for ioremap() regions.
  49  * Can be overriden by arch-specific value.
  50  */
  51 #ifndef IOREMAP_MAX_ORDER
  52 #define IOREMAP_MAX_ORDER       (7 + PAGE_SHIFT)        /* 128 pages */
  53 #endif
  54
  55 struct vm_struct {
  56         struct vm_struct        *next;
  57         void                    *addr;
  58         unsigned long           size;
  59         unsigned long           flags;
  60         struct page             **pages;
  61         unsigned int            nr_pages;
  62         phys_addr_t             phys_addr;
  63         const void              *caller;
  64 };
  65
  66 struct vmap_area {
  67         unsigned long va_start;
  68         unsigned long va_end;
  69
  70         struct rb_node rb_node;         /* address sorted rbtree */
  71         struct list_head list;          /* address sorted list */
  72
  73         /*
  74          * The following three variables can be packed, because
  75          * a vmap_area object is always one of the three states:
  76          *    1) in "free" tree (root is vmap_area_root)
  77          *    2) in "busy" tree (root is free_vmap_area_root)
  78          *    3) in purge list  (head is vmap_purge_list)
  79          */
  80         union {
  81                 unsigned long subtree_max_size; /* in "free" tree */
  82                 struct vm_struct *vm;           /* in "busy" tree */
  83                 struct llist_node purge_list;   /* in purge list */
  84         };
  85 };
  86
  87 /*
  88  *      Highlevel APIs for driver use
  89  */
  90 extern void vm_unmap_ram(const void *mem, unsigned int count);
  91 extern void *vm_map_ram(struct page **pages, unsigned int count, int node);
  92 extern void vm_unmap_aliases(void);
  93
  94 #ifdef CONFIG_MMU
  95 extern void __init vmalloc_init(void);
  96 extern unsigned long vmalloc_nr_pages(void);
  97 #else
  98 static inline void vmalloc_init(void)
  99 {
 100 }
 101 static inline unsigned long vmalloc_nr_pages(void) { return 0; }
 102 #endif
 103
 104 extern void *vmalloc(unsigned long size);
 105 extern void *vzalloc(unsigned long size);
 106 extern void *vmalloc_user(unsigned long size);
 107 extern void *vmalloc_node(unsigned long size, int node);
 108 extern void *vzalloc_node(unsigned long size, int node);
 109 extern void *vmalloc_user_node_flags(unsigned long size, int node, gfp_t flags);
 110 extern void *vmalloc_exec(unsigned long size);
 111 extern void *vmalloc_32(unsigned long size);
 112 extern void *vmalloc_32_user(unsigned long size);
 113 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask);
 114 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 115                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 116                         pgprot_t prot, unsigned long vm_flags, int node,
 117                         const void *caller);
 118 #ifndef CONFIG_MMU
 119 extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags);
 120 static inline void *__vmalloc_node_flags_caller(unsigned long size, int node,
 121                                                 gfp_t flags, void *caller)
 122 {
 123         return __vmalloc_node_flags(size, node, flags);
 124 }
 125 #else
 126 extern void *__vmalloc_node_flags_caller(unsigned long size,
 127                                          int node, gfp_t flags, void *caller);
 128 #endif
 129
 130 extern void vfree(const void *addr);
 131 extern void vfree_atomic(const void *addr);
 132
 133 extern void *vmap(struct page **pages, unsigned int count,
 134                         unsigned long flags, pgprot_t prot);
 135 extern void vunmap(const void *addr);
 136
 137 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
 138                                        unsigned long uaddr, void *kaddr,
 139                                        unsigned long pgoff, unsigned long size);
 140
 141 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 142                                                         unsigned long pgoff);
 143 void vmalloc_sync_mappings(void);
 144 void vmalloc_sync_unmappings(void);
 145
 146 /*
 147  *      Lowlevel-APIs (not for driver use!)
 148  */
 149
 150 static inline size_t get_vm_area_size(const struct vm_struct *area)
 151 {
 152         if (!(area->flags & VM_NO_GUARD))
 153                 /* return actual size without guard page */
 154                 return area->size - PAGE_SIZE;
 155         else
 156                 return area->size;
 157
 158 }
 159
 160 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
 161 extern struct vm_struct *get_vm_area_caller(unsigned long size,
 162                                         unsigned long flags, const void *caller);
 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 #ifdef CONFIG_MMU
 171 extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
 172                                     pgprot_t prot, struct page **pages);
 173 int map_kernel_range(unsigned long start, unsigned long size, pgprot_t prot,
 174                 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 #define map_kernel_range map_kernel_range_noflush
 192 static inline void
 193 unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
 194 {
 195 }
 196 #define unmap_kernel_range unmap_kernel_range_noflush
 197 static inline void set_vm_flush_reset_perms(void *addr)
 198 {
 199 }
 200 #endif
 201
 202 /* Allocate/destroy a 'vmalloc' VM area. */
 203 extern struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes);
 204 extern void free_vm_area(struct vm_struct *area);
 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 */