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 #define VM_NO_HUGE_VMAP         0x00000400      /* force PAGE_SIZE pte mapping */
  30
  31 /*
  32  * VM_KASAN is used slightly differently depending on CONFIG_KASAN_VMALLOC.
  33  *
  34  * If IS_ENABLED(CONFIG_KASAN_VMALLOC), VM_KASAN is set on a vm_struct after
  35  * shadow memory has been mapped. It's used to handle allocation errors so that
  36  * we don't try to poison shadow on free if it was never allocated.
  37  *
  38  * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
  39  * determine which allocations need the module shadow freed.
  40  */
  41
  42 /* bits [20..32] reserved for arch specific ioremap internals */
  43
  44 /*
  45  * Maximum alignment for ioremap() regions.
  46  * Can be overridden by arch-specific value.
  47  */
  48 #ifndef IOREMAP_MAX_ORDER
  49 #define IOREMAP_MAX_ORDER       (7 + PAGE_SHIFT)        /* 128 pages */
  50 #endif
  51
  52 struct vm_struct {
  53         struct vm_struct        *next;
  54         void                    *addr;
  55         unsigned long           size;
  56         unsigned long           flags;
  57         struct page             **pages;
  58 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
  59         unsigned int            page_order;
  60 #endif
  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 two variables can be packed, because
  75          * a vmap_area object can be either:
  76          *    1) in "free" tree (root is vmap_area_root)
  77          *    2) or "busy" tree (root is free_vmap_area_root)
  78          */
  79         union {
  80                 unsigned long subtree_max_size; /* in "free" tree */
  81                 struct vm_struct *vm;           /* in "busy" tree */
  82         };
  83 };
  84
  85 /* archs that select HAVE_ARCH_HUGE_VMAP should override one or more of these */
  86 #ifndef arch_vmap_p4d_supported
  87 static inline bool arch_vmap_p4d_supported(pgprot_t prot)
  88 {
  89         return false;
  90 }
  91 #endif
  92
  93 #ifndef arch_vmap_pud_supported
  94 static inline bool arch_vmap_pud_supported(pgprot_t prot)
  95 {
  96         return false;
  97 }
  98 #endif
  99
 100 #ifndef arch_vmap_pmd_supported
 101 static inline bool arch_vmap_pmd_supported(pgprot_t prot)
 102 {
 103         return false;
 104 }
 105 #endif
 106
 107 #ifndef arch_vmap_pte_range_map_size
 108 static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr, unsigned long end,
 109                                                          u64 pfn, unsigned int max_page_shift)
 110 {
 111         return PAGE_SIZE;
 112 }
 113 #endif
 114
 115 #ifndef arch_vmap_pte_supported_shift
 116 static inline int arch_vmap_pte_supported_shift(unsigned long size)
 117 {
 118         return PAGE_SHIFT;
 119 }
 120 #endif
 121
 122 /*
 123  *      Highlevel APIs for driver use
 124  */
 125 extern void vm_unmap_ram(const void *mem, unsigned int count);
 126 extern void *vm_map_ram(struct page **pages, unsigned int count, int node);
 127 extern void vm_unmap_aliases(void);
 128
 129 #ifdef CONFIG_MMU
 130 extern void __init vmalloc_init(void);
 131 extern unsigned long vmalloc_nr_pages(void);
 132 #else
 133 static inline void vmalloc_init(void)
 134 {
 135 }
 136 static inline unsigned long vmalloc_nr_pages(void) { return 0; }
 137 #endif
 138
 139 extern void *vmalloc(unsigned long size);
 140 extern void *vzalloc(unsigned long size);
 141 extern void *vmalloc_user(unsigned long size);
 142 extern void *vmalloc_node(unsigned long size, int node);
 143 extern void *vzalloc_node(unsigned long size, int node);
 144 extern void *vmalloc_32(unsigned long size);
 145 extern void *vmalloc_32_user(unsigned long size);
 146 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask);
 147 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 148                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 149                         pgprot_t prot, unsigned long vm_flags, int node,
 150                         const void *caller);
 151 void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
 152                 int node, const void *caller);
 153 void *vmalloc_no_huge(unsigned long size);
 154
 155 extern void vfree(const void *addr);
 156 extern void vfree_atomic(const void *addr);
 157
 158 extern void *vmap(struct page **pages, unsigned int count,
 159                         unsigned long flags, pgprot_t prot);
 160 void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot);
 161 extern void vunmap(const void *addr);
 162
 163 extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
 164                                        unsigned long uaddr, void *kaddr,
 165                                        unsigned long pgoff, unsigned long size);
 166
 167 extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 168                                                         unsigned long pgoff);
 169
 170 /*
 171  * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values
 172  * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings()
 173  * needs to be called.
 174  */
 175 #ifndef ARCH_PAGE_TABLE_SYNC_MASK
 176 #define ARCH_PAGE_TABLE_SYNC_MASK 0
 177 #endif
 178
 179 /*
 180  * There is no default implementation for arch_sync_kernel_mappings(). It is
 181  * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK
 182  * is 0.
 183  */
 184 void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
 185
 186 /*
 187  *      Lowlevel-APIs (not for driver use!)
 188  */
 189
 190 static inline size_t get_vm_area_size(const struct vm_struct *area)
 191 {
 192         if (!(area->flags & VM_NO_GUARD))
 193                 /* return actual size without guard page */
 194                 return area->size - PAGE_SIZE;
 195         else
 196                 return area->size;
 197
 198 }
 199
 200 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
 201 extern struct vm_struct *get_vm_area_caller(unsigned long size,
 202                                         unsigned long flags, const void *caller);
 203 extern struct vm_struct *__get_vm_area_caller(unsigned long size,
 204                                         unsigned long flags,
 205                                         unsigned long start, unsigned long end,
 206                                         const void *caller);
 207 void free_vm_area(struct vm_struct *area);
 208 extern struct vm_struct *remove_vm_area(const void *addr);
 209 extern struct vm_struct *find_vm_area(const void *addr);
 210
 211 static inline bool is_vm_area_hugepages(const void *addr)
 212 {
 213         /*
 214          * This may not 100% tell if the area is mapped with > PAGE_SIZE
 215          * page table entries, if for some reason the architecture indicates
 216          * larger sizes are available but decides not to use them, nothing
 217          * prevents that. This only indicates the size of the physical page
 218          * allocated in the vmalloc layer.
 219          */
 220 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
 221         return find_vm_area(addr)->page_order > 0;
 222 #else
 223         return false;
 224 #endif
 225 }
 226
 227 #ifdef CONFIG_MMU
 228 void vunmap_range(unsigned long addr, unsigned long end);
 229 static inline void set_vm_flush_reset_perms(void *addr)
 230 {
 231         struct vm_struct *vm = find_vm_area(addr);
 232
 233         if (vm)
 234                 vm->flags |= VM_FLUSH_RESET_PERMS;
 235 }
 236
 237 #else
 238 static inline void set_vm_flush_reset_perms(void *addr)
 239 {
 240 }
 241 #endif
 242
 243 /* for /proc/kcore */
 244 extern long vread(char *buf, char *addr, unsigned long count);
 245
 246 /*
 247  *      Internals.  Don't use..
 248  */
 249 extern struct list_head vmap_area_list;
 250 extern __init void vm_area_add_early(struct vm_struct *vm);
 251 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
 252
 253 #ifdef CONFIG_SMP
 254 # ifdef CONFIG_MMU
 255 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 256                                      const size_t *sizes, int nr_vms,
 257                                      size_t align);
 258
 259 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
 260 # else
 261 static inline struct vm_struct **
 262 pcpu_get_vm_areas(const unsigned long *offsets,
 263                 const size_t *sizes, int nr_vms,
 264                 size_t align)
 265 {
 266         return NULL;
 267 }
 268
 269 static inline void
 270 pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 271 {
 272 }
 273 # endif
 274 #endif
 275
 276 #ifdef CONFIG_MMU
 277 #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)
 278 #else
 279 #define VMALLOC_TOTAL 0UL
 280 #endif
 281
 282 int register_vmap_purge_notifier(struct notifier_block *nb);
 283 int unregister_vmap_purge_notifier(struct notifier_block *nb);
 284
 285 #if defined(CONFIG_MMU) && defined(CONFIG_PRINTK)
 286 bool vmalloc_dump_obj(void *object);
 287 #else
 288 static inline bool vmalloc_dump_obj(void *object) { return false; }
 289 #endif
 290
 291 #endif /* _LINUX_VMALLOC_H */