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 #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 */