gfp.h 6.2 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. #define __GFP_WAIT ((__force gfp_t)0x10u) /* Can wait and reschedule? */
  31. #define __GFP_HIGH ((__force gfp_t)0x20u) /* Should access emergency pools? */
  32. #define __GFP_IO ((__force gfp_t)0x40u) /* Can start physical IO? */
  33. #define __GFP_FS ((__force gfp_t)0x80u) /* Can call down to low-level FS? */
  34. #define __GFP_COLD ((__force gfp_t)0x100u) /* Cache-cold page required */
  35. #define __GFP_NOWARN ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
  36. #define __GFP_REPEAT ((__force gfp_t)0x400u) /* Retry the allocation. Might fail */
  37. #define __GFP_NOFAIL ((__force gfp_t)0x800u) /* Retry for ever. Cannot fail */
  38. #define __GFP_NORETRY ((__force gfp_t)0x1000u)/* Do not retry. Might fail */
  39. #define __GFP_NO_GROW ((__force gfp_t)0x2000u)/* Slab internal usage */
  40. #define __GFP_COMP ((__force gfp_t)0x4000u)/* Add compound page metadata */
  41. #define __GFP_ZERO ((__force gfp_t)0x8000u)/* Return zeroed page on success */
  42. #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
  43. #define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
  44. #define __GFP_THISNODE ((__force gfp_t)0x40000u)/* No fallback, no policies */
  45. #define __GFP_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */
  46. #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
  47. /* if you forget to add the bitmask here kernel will crash, period */
  48. #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
  49. __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
  50. __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
  51. __GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE)
  52. /* This equals 0, but use constants in case they ever change */
  53. #define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
  54. /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
  55. #define GFP_ATOMIC (__GFP_HIGH)
  56. #define GFP_NOIO (__GFP_WAIT)
  57. #define GFP_NOFS (__GFP_WAIT | __GFP_IO)
  58. #define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
  59. #define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
  60. #define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
  61. __GFP_HIGHMEM)
  62. #ifdef CONFIG_NUMA
  63. #define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
  64. #else
  65. #define GFP_THISNODE ((__force gfp_t)0)
  66. #endif
  67. /* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
  68. platforms, used as appropriate on others */
  69. #define GFP_DMA __GFP_DMA
  70. /* 4GB DMA on some platforms */
  71. #define GFP_DMA32 __GFP_DMA32
  72. static inline enum zone_type gfp_zone(gfp_t flags)
  73. {
  74. #ifdef CONFIG_ZONE_DMA
  75. if (flags & __GFP_DMA)
  76. return ZONE_DMA;
  77. #endif
  78. #ifdef CONFIG_ZONE_DMA32
  79. if (flags & __GFP_DMA32)
  80. return ZONE_DMA32;
  81. #endif
  82. #ifdef CONFIG_HIGHMEM
  83. if (flags & __GFP_HIGHMEM)
  84. return ZONE_HIGHMEM;
  85. #endif
  86. return ZONE_NORMAL;
  87. }
  88. /*
  89. * There is only one page-allocator function, and two main namespaces to
  90. * it. The alloc_page*() variants return 'struct page *' and as such
  91. * can allocate highmem pages, the *get*page*() variants return
  92. * virtual kernel addresses to the allocated page(s).
  93. */
  94. /*
  95. * We get the zone list from the current node and the gfp_mask.
  96. * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
  97. *
  98. * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
  99. * optimized to &contig_page_data at compile-time.
  100. */
  101. #ifndef HAVE_ARCH_FREE_PAGE
  102. static inline void arch_free_page(struct page *page, int order) { }
  103. #endif
  104. #ifndef HAVE_ARCH_ALLOC_PAGE
  105. static inline void arch_alloc_page(struct page *page, int order) { }
  106. #endif
  107. extern struct page *
  108. FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
  109. static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
  110. unsigned int order)
  111. {
  112. if (unlikely(order >= MAX_ORDER))
  113. return NULL;
  114. /* Unknown node is current node */
  115. if (nid < 0)
  116. nid = numa_node_id();
  117. return __alloc_pages(gfp_mask, order,
  118. NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
  119. }
  120. #ifdef CONFIG_NUMA
  121. extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
  122. static inline struct page *
  123. alloc_pages(gfp_t gfp_mask, unsigned int order)
  124. {
  125. if (unlikely(order >= MAX_ORDER))
  126. return NULL;
  127. return alloc_pages_current(gfp_mask, order);
  128. }
  129. extern struct page *alloc_page_vma(gfp_t gfp_mask,
  130. struct vm_area_struct *vma, unsigned long addr);
  131. #else
  132. #define alloc_pages(gfp_mask, order) \
  133. alloc_pages_node(numa_node_id(), gfp_mask, order)
  134. #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
  135. #endif
  136. #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
  137. extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
  138. extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
  139. #define __get_free_page(gfp_mask) \
  140. __get_free_pages((gfp_mask),0)
  141. #define __get_dma_pages(gfp_mask, order) \
  142. __get_free_pages((gfp_mask) | GFP_DMA,(order))
  143. extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
  144. extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
  145. extern void FASTCALL(free_hot_page(struct page *page));
  146. extern void FASTCALL(free_cold_page(struct page *page));
  147. #define __free_page(page) __free_pages((page), 0)
  148. #define free_page(addr) free_pages((addr),0)
  149. void page_alloc_init(void);
  150. #ifdef CONFIG_NUMA
  151. void drain_node_pages(int node);
  152. #else
  153. static inline void drain_node_pages(int node) { };
  154. #endif
  155. #endif /* __LINUX_GFP_H */