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_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);
 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 void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
 118                 int node, const void *caller);
 119
 120 extern void vfree(const void *addr);
 121 extern void vfree_atomic(const void *addr);
 122
 123 extern void *vmap(struct page **pages, unsigned int count,
 124                         unsigned long flags, pgprot_t prot);
 125 extern void vunmap(const void *addr);
 126
 127 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
 128                                        unsigned long uaddr, void *kaddr,
 129                                        unsigned long pgoff, unsigned long size);
 130
 131 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 132                                                         unsigned long pgoff);
 133
 134 /*
 135  * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values
 136  * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings()
 137  * needs to be called.
 138  */
 139 #ifndef ARCH_PAGE_TABLE_SYNC_MASK
 140 #define ARCH_PAGE_TABLE_SYNC_MASK 0
 141 #endif
 142
 143 /*
 144  * There is no default implementation for arch_sync_kernel_mappings(). It is
 145  * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK
 146  * is 0.
 147  */
 148 void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
 149
 150 /*
 151  *      Lowlevel-APIs (not for driver use!)
 152  */
 153
 154 static inline size_t get_vm_area_size(const struct vm_struct *area)
 155 {
 156         if (!(area->flags & VM_NO_GUARD))
 157                 /* return actual size without guard page */
 158                 return area->size - PAGE_SIZE;
 159         else
 160                 return area->size;
 161
 162 }
 163
 164 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
 165 extern struct vm_struct *get_vm_area_caller(unsigned long size,
 166                                         unsigned long flags, const void *caller);
 167 extern struct vm_struct *__get_vm_area_caller(unsigned long size,
 168                                         unsigned long flags,
 169                                         unsigned long start, unsigned long end,
 170                                         const void *caller);
 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 /* Allocate/destroy a 'vmalloc' VM area. */
 207 extern struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes);
 208 extern void free_vm_area(struct vm_struct *area);
 209
 210 /* for /dev/kmem */
 211 extern long vread(char *buf, char *addr, unsigned long count);
 212 extern long vwrite(char *buf, char *addr, unsigned long count);
 213
 214 /*
 215  *      Internals.  Dont't use..
 216  */
 217 extern struct list_head vmap_area_list;
 218 extern __init void vm_area_add_early(struct vm_struct *vm);
 219 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
 220
 221 #ifdef CONFIG_SMP
 222 # ifdef CONFIG_MMU
 223 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 224                                      const size_t *sizes, int nr_vms,
 225                                      size_t align);
 226
 227 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
 228 # else
 229 static inline struct vm_struct **
 230 pcpu_get_vm_areas(const unsigned long *offsets,
 231                 const size_t *sizes, int nr_vms,
 232                 size_t align)
 233 {
 234         return NULL;
 235 }
 236
 237 static inline void
 238 pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 239 {
 240 }
 241 # endif
 242 #endif
 243
 244 #ifdef CONFIG_MMU
 245 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
 246 #else
 247 #define VMALLOC_TOTAL 0UL
 248 #endif
 249
 250 int register_vmap_purge_notifier(struct notifier_block *nb);
 251 int unregister_vmap_purge_notifier(struct notifier_block *nb);
 252
 253 #endif /* _LINUX_VMALLOC_H */