gfp.h 7.1 KB

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  1. #ifndef __LINUX_GFP_H
  2. #define __LINUX_GFP_H
  3. #include <linux/mmzone.h>
  4. #include <linux/stddef.h>
  5. #include <linux/linkage.h>
  6. struct vm_area_struct;
  7. /*
  8. * GFP bitmasks..
  9. *
  10. * Zone modifiers (see linux/mmzone.h - low three bits)
  11. *
  12. * Do not put any conditional on these. If necessary modify the definitions
  13. * without the underscores and use the consistently. The definitions here may
  14. * be used in bit comparisons.
  15. */
  16. #define __GFP_DMA ((__force gfp_t)0x01u)
  17. #define __GFP_HIGHMEM ((__force gfp_t)0x02u)
  18. #define __GFP_DMA32 ((__force gfp_t)0x04u)
  19. /*
  20. * Action modifiers - doesn't change the zoning
  21. *
  22. * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
  23. * _might_ fail. This depends upon the particular VM implementation.
  24. *
  25. * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
  26. * cannot handle allocation failures.
  27. *
  28. * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  29. *
  30. * __GFP_MOVABLE: Flag that this page will be movable by the page migration
  31. * mechanism or reclaimed
  32. */
  33. #define __GFP_WAIT ((__force gfp_t)0x10u) /* Can wait and reschedule? */
  34. #define __GFP_HIGH ((__force gfp_t)0x20u) /* Should access emergency pools? */
  35. #define __GFP_IO ((__force gfp_t)0x40u) /* Can start physical IO? */
  36. #define __GFP_FS ((__force gfp_t)0x80u) /* Can call down to low-level FS? */
  37. #define __GFP_COLD ((__force gfp_t)0x100u) /* Cache-cold page required */
  38. #define __GFP_NOWARN ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  39. #define __GFP_REPEAT ((__force gfp_t)0x400u) /* Retry the allocation. Might fail */
  40. #define __GFP_NOFAIL ((__force gfp_t)0x800u) /* Retry for ever. Cannot fail */
  41. #define __GFP_NORETRY ((__force gfp_t)0x1000u)/* Do not retry. Might fail */
  42. #define __GFP_COMP ((__force gfp_t)0x4000u)/* Add compound page metadata */
  43. #define __GFP_ZERO ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  44. #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  45. #define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  46. #define __GFP_THISNODE ((__force gfp_t)0x40000u)/* No fallback, no policies */
  47. #define __GFP_MOVABLE ((__force gfp_t)0x80000u) /* Page is movable */
  48. #define __GFP_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */
  49. #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  50. /* This equals 0, but use constants in case they ever change */
  51. #define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
  52. /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  53. #define GFP_ATOMIC (__GFP_HIGH)
  54. #define GFP_NOIO (__GFP_WAIT)
  55. #define GFP_NOFS (__GFP_WAIT | __GFP_IO)
  56. #define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
  57. #define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  58. #define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  59. __GFP_HIGHMEM)
  60. #define GFP_HIGHUSER_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  61. __GFP_HARDWALL | __GFP_HIGHMEM | \
  62. __GFP_MOVABLE)
  63. #define GFP_NOFS_PAGECACHE (__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
  64. #define GFP_USER_PAGECACHE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  65. __GFP_HARDWALL | __GFP_MOVABLE)
  66. #define GFP_HIGHUSER_PAGECACHE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
  67. __GFP_HARDWALL | __GFP_HIGHMEM | \
  68. __GFP_MOVABLE)
  69. #ifdef CONFIG_NUMA
  70. #define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  71. #else
  72. #define GFP_THISNODE ((__force gfp_t)0)
  73. #endif
  74. /* This mask makes up all the page movable related flags */
  75. #define GFP_MOVABLE_MASK (__GFP_MOVABLE)
  76. /* Control page allocator reclaim behavior */
  77. #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
  78. __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
  79. __GFP_NORETRY|__GFP_NOMEMALLOC)
  80. /* Control allocation constraints */
  81. #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
  82. /* Do not use these with a slab allocator */
  83. #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
  84. /* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
  85. platforms, used as appropriate on others */
  86. #define GFP_DMA __GFP_DMA
  87. /* 4GB DMA on some platforms */
  88. #define GFP_DMA32 __GFP_DMA32
  89. static inline enum zone_type gfp_zone(gfp_t flags)
  90. {
  91. int base = 0;
  92. #ifdef CONFIG_NUMA
  93. if (flags & __GFP_THISNODE)
  94. base = MAX_NR_ZONES;
  95. #endif
  96. #ifdef CONFIG_ZONE_DMA
  97. if (flags & __GFP_DMA)
  98. return base + ZONE_DMA;
  99. #endif
  100. #ifdef CONFIG_ZONE_DMA32
  101. if (flags & __GFP_DMA32)
  102. return base + ZONE_DMA32;
  103. #endif
  104. if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
  105. (__GFP_HIGHMEM | __GFP_MOVABLE))
  106. return base + ZONE_MOVABLE;
  107. #ifdef CONFIG_HIGHMEM
  108. if (flags & __GFP_HIGHMEM)
  109. return base + ZONE_HIGHMEM;
  110. #endif
  111. return base + ZONE_NORMAL;
  112. }
  113. /*
  114. * There is only one page-allocator function, and two main namespaces to
  115. * it. The alloc_page*() variants return 'struct page *' and as such
  116. * can allocate highmem pages, the *get*page*() variants return
  117. * virtual kernel addresses to the allocated page(s).
  118. */
  119. /*
  120. * We get the zone list from the current node and the gfp_mask.
  121. * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
  122. *
  123. * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
  124. * optimized to &contig_page_data at compile-time.
  125. */
  126. #ifndef HAVE_ARCH_FREE_PAGE
  127. static inline void arch_free_page(struct page *page, int order) { }
  128. #endif
  129. #ifndef HAVE_ARCH_ALLOC_PAGE
  130. static inline void arch_alloc_page(struct page *page, int order) { }
  131. #endif
  132. extern struct page *
  133. FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
  134. static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
  135. unsigned int order)
  136. {
  137. if (unlikely(order >= MAX_ORDER))
  138. return NULL;
  139. /* Unknown node is current node */
  140. if (nid < 0)
  141. nid = numa_node_id();
  142. return __alloc_pages(gfp_mask, order,
  143. NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
  144. }
  145. #ifdef CONFIG_NUMA
  146. extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
  147. static inline struct page *
  148. alloc_pages(gfp_t gfp_mask, unsigned int order)
  149. {
  150. if (unlikely(order >= MAX_ORDER))
  151. return NULL;
  152. return alloc_pages_current(gfp_mask, order);
  153. }
  154. extern struct page *alloc_page_vma(gfp_t gfp_mask,
  155. struct vm_area_struct *vma, unsigned long addr);
  156. #else
  157. #define alloc_pages(gfp_mask, order) \
  158. alloc_pages_node(numa_node_id(), gfp_mask, order)
  159. #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
  160. #endif
  161. #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
  162. extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
  163. extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
  164. #define __get_free_page(gfp_mask) \
  165. __get_free_pages((gfp_mask),0)
  166. #define __get_dma_pages(gfp_mask, order) \
  167. __get_free_pages((gfp_mask) | GFP_DMA,(order))
  168. extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
  169. extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
  170. extern void FASTCALL(free_hot_page(struct page *page));
  171. extern void FASTCALL(free_cold_page(struct page *page));
  172. #define __free_page(page) __free_pages((page), 0)
  173. #define free_page(addr) free_pages((addr),0)
  174. void page_alloc_init(void);
  175. void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
  176. #endif /* __LINUX_GFP_H */