linux/include/linux/gfp.h
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   1#ifndef __LINUX_GFP_H
   2#define __LINUX_GFP_H
   3
   4#include <linux/mmzone.h>
   5#include <linux/stddef.h>
   6#include <linux/linkage.h>
   7#include <linux/topology.h>
   8#include <linux/mmdebug.h>
   9
  10struct vm_area_struct;
  11
  12/* Plain integer GFP bitmasks. Do not use this directly. */
  13#define ___GFP_DMA              0x01u
  14#define ___GFP_HIGHMEM          0x02u
  15#define ___GFP_DMA32            0x04u
  16#define ___GFP_MOVABLE          0x08u
  17#define ___GFP_WAIT             0x10u
  18#define ___GFP_HIGH             0x20u
  19#define ___GFP_IO               0x40u
  20#define ___GFP_FS               0x80u
  21#define ___GFP_COLD             0x100u
  22#define ___GFP_NOWARN           0x200u
  23#define ___GFP_REPEAT           0x400u
  24#define ___GFP_NOFAIL           0x800u
  25#define ___GFP_NORETRY          0x1000u
  26#define ___GFP_MEMALLOC         0x2000u
  27#define ___GFP_COMP             0x4000u
  28#define ___GFP_ZERO             0x8000u
  29#define ___GFP_NOMEMALLOC       0x10000u
  30#define ___GFP_HARDWALL         0x20000u
  31#define ___GFP_THISNODE         0x40000u
  32#define ___GFP_RECLAIMABLE      0x80000u
  33#define ___GFP_KMEMCG           0x100000u
  34#define ___GFP_NOTRACK          0x200000u
  35#define ___GFP_NO_KSWAPD        0x400000u
  36#define ___GFP_OTHER_NODE       0x800000u
  37#define ___GFP_WRITE            0x1000000u
  38/* If the above are modified, __GFP_BITS_SHIFT may need updating */
  39
  40/*
  41 * GFP bitmasks..
  42 *
  43 * Zone modifiers (see linux/mmzone.h - low three bits)
  44 *
  45 * Do not put any conditional on these. If necessary modify the definitions
  46 * without the underscores and use them consistently. The definitions here may
  47 * be used in bit comparisons.
  48 */
  49#define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
  50#define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
  51#define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
  52#define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* Page is movable */
  53#define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  54/*
  55 * Action modifiers - doesn't change the zoning
  56 *
  57 * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  58 * _might_ fail.  This depends upon the particular VM implementation.
  59 *
  60 * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  61 * cannot handle allocation failures.  This modifier is deprecated and no new
  62 * users should be added.
  63 *
  64 * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  65 *
  66 * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  67 * mechanism or reclaimed
  68 */
  69#define __GFP_WAIT      ((__force gfp_t)___GFP_WAIT)    /* Can wait and reschedule? */
  70#define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)    /* Should access emergency pools? */
  71#define __GFP_IO        ((__force gfp_t)___GFP_IO)      /* Can start physical IO? */
  72#define __GFP_FS        ((__force gfp_t)___GFP_FS)      /* Can call down to low-level FS? */
  73#define __GFP_COLD      ((__force gfp_t)___GFP_COLD)    /* Cache-cold page required */
  74#define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)  /* Suppress page allocation failure warning */
  75#define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)  /* See above */
  76#define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)  /* See above */
  77#define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY) /* See above */
  78#define __GFP_MEMALLOC  ((__force gfp_t)___GFP_MEMALLOC)/* Allow access to emergency reserves */
  79#define __GFP_COMP      ((__force gfp_t)___GFP_COMP)    /* Add compound page metadata */
  80#define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)    /* Return zeroed page on success */
  81#define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves.
  82                                                         * This takes precedence over the
  83                                                         * __GFP_MEMALLOC flag if both are
  84                                                         * set
  85                                                         */
  86#define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */
  87#define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */
  88#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */
  89#define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)  /* Don't track with kmemcheck */
  90
  91#define __GFP_NO_KSWAPD ((__force gfp_t)___GFP_NO_KSWAPD)
  92#define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
  93#define __GFP_KMEMCG    ((__force gfp_t)___GFP_KMEMCG) /* Allocation comes from a memcg-accounted resource */
  94#define __GFP_WRITE     ((__force gfp_t)___GFP_WRITE)   /* Allocator intends to dirty page */
  95
  96/*
  97 * This may seem redundant, but it's a way of annotating false positives vs.
  98 * allocations that simply cannot be supported (e.g. page tables).
  99 */
 100#define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
 101
 102#define __GFP_BITS_SHIFT 25     /* Room for N __GFP_FOO bits */
 103#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 104
 105/* This equals 0, but use constants in case they ever change */
 106#define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
 107/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
 108#define GFP_ATOMIC      (__GFP_HIGH)
 109#define GFP_NOIO        (__GFP_WAIT)
 110#define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
 111#define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
 112#define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 113                         __GFP_RECLAIMABLE)
 114#define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
 115#define GFP_HIGHUSER    (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
 116                         __GFP_HIGHMEM)
 117#define GFP_HIGHUSER_MOVABLE    (__GFP_WAIT | __GFP_IO | __GFP_FS | \
 118                                 __GFP_HARDWALL | __GFP_HIGHMEM | \
 119                                 __GFP_MOVABLE)
 120#define GFP_IOFS        (__GFP_IO | __GFP_FS)
 121#define GFP_TRANSHUGE   (GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
 122                         __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | \
 123                         __GFP_NO_KSWAPD)
 124
 125#ifdef CONFIG_NUMA
 126#define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
 127#else
 128#define GFP_THISNODE    ((__force gfp_t)0)
 129#endif
 130
 131/* This mask makes up all the page movable related flags */
 132#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
 133
 134/* Control page allocator reclaim behavior */
 135#define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
 136                        __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
 137                        __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
 138
 139/* Control slab gfp mask during early boot */
 140#define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS))
 141
 142/* Control allocation constraints */
 143#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
 144
 145/* Do not use these with a slab allocator */
 146#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
 147
 148/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 149   platforms, used as appropriate on others */
 150
 151#define GFP_DMA         __GFP_DMA
 152
 153/* 4GB DMA on some platforms */
 154#define GFP_DMA32       __GFP_DMA32
 155
 156/* Convert GFP flags to their corresponding migrate type */
 157static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 158{
 159        WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 160
 161        if (unlikely(page_group_by_mobility_disabled))
 162                return MIGRATE_UNMOVABLE;
 163
 164        /* Group based on mobility */
 165        return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
 166                ((gfp_flags & __GFP_RECLAIMABLE) != 0);
 167}
 168
 169#ifdef CONFIG_HIGHMEM
 170#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
 171#else
 172#define OPT_ZONE_HIGHMEM ZONE_NORMAL
 173#endif
 174
 175#ifdef CONFIG_ZONE_DMA
 176#define OPT_ZONE_DMA ZONE_DMA
 177#else
 178#define OPT_ZONE_DMA ZONE_NORMAL
 179#endif
 180
 181#ifdef CONFIG_ZONE_DMA32
 182#define OPT_ZONE_DMA32 ZONE_DMA32
 183#else
 184#define OPT_ZONE_DMA32 ZONE_NORMAL
 185#endif
 186
 187/*
 188 * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
 189 * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
 190 * and there are 16 of them to cover all possible combinations of
 191 * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
 192 *
 193 * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
 194 * But GFP_MOVABLE is not only a zone specifier but also an allocation
 195 * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
 196 * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
 197 *
 198 *       bit       result
 199 *       =================
 200 *       0x0    => NORMAL
 201 *       0x1    => DMA or NORMAL
 202 *       0x2    => HIGHMEM or NORMAL
 203 *       0x3    => BAD (DMA+HIGHMEM)
 204 *       0x4    => DMA32 or DMA or NORMAL
 205 *       0x5    => BAD (DMA+DMA32)
 206 *       0x6    => BAD (HIGHMEM+DMA32)
 207 *       0x7    => BAD (HIGHMEM+DMA32+DMA)
 208 *       0x8    => NORMAL (MOVABLE+0)
 209 *       0x9    => DMA or NORMAL (MOVABLE+DMA)
 210 *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
 211 *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
 212 *       0xc    => DMA32 (MOVABLE+HIGHMEM+DMA32)
 213 *       0xd    => BAD (MOVABLE+DMA32+DMA)
 214 *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
 215 *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
 216 *
 217 * ZONES_SHIFT must be <= 2 on 32 bit platforms.
 218 */
 219
 220#if 16 * ZONES_SHIFT > BITS_PER_LONG
 221#error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 222#endif
 223
 224#define GFP_ZONE_TABLE ( \
 225        (ZONE_NORMAL << 0 * ZONES_SHIFT)                                      \
 226        | (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT)                          \
 227        | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT)                  \
 228        | (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT)                      \
 229        | (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT)                       \
 230        | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT)       \
 231        | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT)   \
 232        | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT)   \
 233)
 234
 235/*
 236 * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
 237 * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
 238 * entry starting with bit 0. Bit is set if the combination is not
 239 * allowed.
 240 */
 241#define GFP_ZONE_BAD ( \
 242        1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
 243        | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
 244        | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
 245        | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
 246        | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
 247        | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
 248        | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
 249        | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
 250)
 251
 252static inline enum zone_type gfp_zone(gfp_t flags)
 253{
 254        enum zone_type z;
 255        int bit = (__force int) (flags & GFP_ZONEMASK);
 256
 257        z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
 258                                         ((1 << ZONES_SHIFT) - 1);
 259        VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 260        return z;
 261}
 262
 263/*
 264 * There is only one page-allocator function, and two main namespaces to
 265 * it. The alloc_page*() variants return 'struct page *' and as such
 266 * can allocate highmem pages, the *get*page*() variants return
 267 * virtual kernel addresses to the allocated page(s).
 268 */
 269
 270static inline int gfp_zonelist(gfp_t flags)
 271{
 272        if (IS_ENABLED(CONFIG_NUMA) && unlikely(flags & __GFP_THISNODE))
 273                return 1;
 274
 275        return 0;
 276}
 277
 278/*
 279 * We get the zone list from the current node and the gfp_mask.
 280 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
 281 * There are two zonelists per node, one for all zones with memory and
 282 * one containing just zones from the node the zonelist belongs to.
 283 *
 284 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
 285 * optimized to &contig_page_data at compile-time.
 286 */
 287static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 288{
 289        return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 290}
 291
 292#ifndef HAVE_ARCH_FREE_PAGE
 293static inline void arch_free_page(struct page *page, int order) { }
 294#endif
 295#ifndef HAVE_ARCH_ALLOC_PAGE
 296static inline void arch_alloc_page(struct page *page, int order) { }
 297#endif
 298
 299struct page *
 300__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 301                       struct zonelist *zonelist, nodemask_t *nodemask);
 302
 303static inline struct page *
 304__alloc_pages(gfp_t gfp_mask, unsigned int order,
 305                struct zonelist *zonelist)
 306{
 307        return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
 308}
 309
 310static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 311                                                unsigned int order)
 312{
 313        /* Unknown node is current node */
 314        if (nid < 0)
 315                nid = numa_node_id();
 316
 317        return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 318}
 319
 320static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask,
 321                                                unsigned int order)
 322{
 323        VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid));
 324
 325        return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
 326}
 327
 328#ifdef CONFIG_NUMA
 329extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
 330
 331static inline struct page *
 332alloc_pages(gfp_t gfp_mask, unsigned int order)
 333{
 334        return alloc_pages_current(gfp_mask, order);
 335}
 336extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
 337                        struct vm_area_struct *vma, unsigned long addr,
 338                        int node);
 339#else
 340#define alloc_pages(gfp_mask, order) \
 341                alloc_pages_node(numa_node_id(), gfp_mask, order)
 342#define alloc_pages_vma(gfp_mask, order, vma, addr, node)       \
 343        alloc_pages(gfp_mask, order)
 344#endif
 345#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 346#define alloc_page_vma(gfp_mask, vma, addr)                     \
 347        alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id())
 348#define alloc_page_vma_node(gfp_mask, vma, addr, node)          \
 349        alloc_pages_vma(gfp_mask, 0, vma, addr, node)
 350
 351extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 352extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 353
 354void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 355void free_pages_exact(void *virt, size_t size);
 356/* This is different from alloc_pages_exact_node !!! */
 357void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
 358
 359#define __get_free_page(gfp_mask) \
 360                __get_free_pages((gfp_mask), 0)
 361
 362#define __get_dma_pages(gfp_mask, order) \
 363                __get_free_pages((gfp_mask) | GFP_DMA, (order))
 364
 365extern void __free_pages(struct page *page, unsigned int order);
 366extern void free_pages(unsigned long addr, unsigned int order);
 367extern void free_hot_cold_page(struct page *page, int cold);
 368extern void free_hot_cold_page_list(struct list_head *list, int cold);
 369
 370extern void __free_memcg_kmem_pages(struct page *page, unsigned int order);
 371extern void free_memcg_kmem_pages(unsigned long addr, unsigned int order);
 372
 373#define __free_page(page) __free_pages((page), 0)
 374#define free_page(addr) free_pages((addr), 0)
 375
 376void page_alloc_init(void);
 377void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
 378void drain_all_pages(void);
 379void drain_local_pages(void *dummy);
 380
 381/*
 382 * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
 383 * GFP flags are used before interrupts are enabled. Once interrupts are
 384 * enabled, it is set to __GFP_BITS_MASK while the system is running. During
 385 * hibernation, it is used by PM to avoid I/O during memory allocation while
 386 * devices are suspended.
 387 */
 388extern gfp_t gfp_allowed_mask;
 389
 390/* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
 391bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
 392
 393extern void pm_restrict_gfp_mask(void);
 394extern void pm_restore_gfp_mask(void);
 395
 396#ifdef CONFIG_PM_SLEEP
 397extern bool pm_suspended_storage(void);
 398#else
 399static inline bool pm_suspended_storage(void)
 400{
 401        return false;
 402}
 403#endif /* CONFIG_PM_SLEEP */
 404
 405#ifdef CONFIG_CMA
 406
 407/* The below functions must be run on a range from a single zone. */
 408extern int alloc_contig_range(unsigned long start, unsigned long end,
 409                              unsigned migratetype);
 410extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
 411
 412/* CMA stuff */
 413extern void init_cma_reserved_pageblock(struct page *page);
 414
 415#endif
 416
 417#endif /* __LINUX_GFP_H */
 418
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