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Linux/include/linux/gfp.h

  1 #ifndef __LINUX_GFP_H
  2 #define __LINUX_GFP_H
  3 
  4 #include <linux/mmdebug.h>
  5 #include <linux/mmzone.h>
  6 #include <linux/stddef.h>
  7 #include <linux/linkage.h>
  8 #include <linux/topology.h>
  9 
 10 struct 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_NOTRACK          0x200000u
 34 #define ___GFP_NO_KSWAPD        0x400000u
 35 #define ___GFP_OTHER_NODE       0x800000u
 36 #define ___GFP_WRITE            0x1000000u
 37 /* If the above are modified, __GFP_BITS_SHIFT may need updating */
 38 
 39 /*
 40  * GFP bitmasks..
 41  *
 42  * Zone modifiers (see linux/mmzone.h - low three bits)
 43  *
 44  * Do not put any conditional on these. If necessary modify the definitions
 45  * without the underscores and use them consistently. The definitions here may
 46  * be used in bit comparisons.
 47  */
 48 #define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
 49 #define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
 50 #define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
 51 #define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* Page is movable */
 52 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
 53 /*
 54  * Action modifiers - doesn't change the zoning
 55  *
 56  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
 57  * _might_ fail.  This depends upon the particular VM implementation.
 58  *
 59  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
 60  * cannot handle allocation failures.  This modifier is deprecated and no new
 61  * users should be added.
 62  *
 63  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
 64  *
 65  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
 66  * mechanism or reclaimed
 67  */
 68 #define __GFP_WAIT      ((__force gfp_t)___GFP_WAIT)    /* Can wait and reschedule? */
 69 #define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)    /* Should access emergency pools? */
 70 #define __GFP_IO        ((__force gfp_t)___GFP_IO)      /* Can start physical IO? */
 71 #define __GFP_FS        ((__force gfp_t)___GFP_FS)      /* Can call down to low-level FS? */
 72 #define __GFP_COLD      ((__force gfp_t)___GFP_COLD)    /* Cache-cold page required */
 73 #define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)  /* Suppress page allocation failure warning */
 74 #define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)  /* See above */
 75 #define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)  /* See above */
 76 #define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY) /* See above */
 77 #define __GFP_MEMALLOC  ((__force gfp_t)___GFP_MEMALLOC)/* Allow access to emergency reserves */
 78 #define __GFP_COMP      ((__force gfp_t)___GFP_COMP)    /* Add compound page metadata */
 79 #define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)    /* Return zeroed page on success */
 80 #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves.
 81                                                          * This takes precedence over the
 82                                                          * __GFP_MEMALLOC flag if both are
 83                                                          * set
 84                                                          */
 85 #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */
 86 #define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */
 87 #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */
 88 #define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)  /* Don't track with kmemcheck */
 89 
 90 #define __GFP_NO_KSWAPD ((__force gfp_t)___GFP_NO_KSWAPD)
 91 #define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
 92 #define __GFP_WRITE     ((__force gfp_t)___GFP_WRITE)   /* Allocator intends to dirty page */
 93 
 94 /*
 95  * This may seem redundant, but it's a way of annotating false positives vs.
 96  * allocations that simply cannot be supported (e.g. page tables).
 97  */
 98 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
 99 
100 #define __GFP_BITS_SHIFT 25     /* Room for N __GFP_FOO bits */
101 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
102 
103 /* This equals 0, but use constants in case they ever change */
104 #define GFP_NOWAIT      (GFP_ATOMIC & ~__GFP_HIGH)
105 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
106 #define GFP_ATOMIC      (__GFP_HIGH)
107 #define GFP_NOIO        (__GFP_WAIT)
108 #define GFP_NOFS        (__GFP_WAIT | __GFP_IO)
109 #define GFP_KERNEL      (__GFP_WAIT | __GFP_IO | __GFP_FS)
110 #define GFP_TEMPORARY   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
111                          __GFP_RECLAIMABLE)
112 #define GFP_USER        (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
113 #define GFP_HIGHUSER    (GFP_USER | __GFP_HIGHMEM)
114 #define GFP_HIGHUSER_MOVABLE    (GFP_HIGHUSER | __GFP_MOVABLE)
115 #define GFP_IOFS        (__GFP_IO | __GFP_FS)
116 #define GFP_TRANSHUGE   (GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
117                          __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | \
118                          __GFP_NO_KSWAPD)
119 
120 /*
121  * GFP_THISNODE does not perform any reclaim, you most likely want to
122  * use __GFP_THISNODE to allocate from a given node without fallback!
123  */
124 #ifdef CONFIG_NUMA
125 #define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
126 #else
127 #define GFP_THISNODE    ((__force gfp_t)0)
128 #endif
129 
130 /* This mask makes up all the page movable related flags */
131 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
132 
133 /* Control page allocator reclaim behavior */
134 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
135                         __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
136                         __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
137 
138 /* Control slab gfp mask during early boot */
139 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS))
140 
141 /* Control allocation constraints */
142 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
143 
144 /* Do not use these with a slab allocator */
145 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
146 
147 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
148    platforms, used as appropriate on others */
149 
150 #define GFP_DMA         __GFP_DMA
151 
152 /* 4GB DMA on some platforms */
153 #define GFP_DMA32       __GFP_DMA32
154 
155 /* Convert GFP flags to their corresponding migrate type */
156 static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
157 {
158         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
159 
160         if (unlikely(page_group_by_mobility_disabled))
161                 return MIGRATE_UNMOVABLE;
162 
163         /* Group based on mobility */
164         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
165                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
166 }
167 
168 #ifdef CONFIG_HIGHMEM
169 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
170 #else
171 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
172 #endif
173 
174 #ifdef CONFIG_ZONE_DMA
175 #define OPT_ZONE_DMA ZONE_DMA
176 #else
177 #define OPT_ZONE_DMA ZONE_NORMAL
178 #endif
179 
180 #ifdef CONFIG_ZONE_DMA32
181 #define OPT_ZONE_DMA32 ZONE_DMA32
182 #else
183 #define OPT_ZONE_DMA32 ZONE_NORMAL
184 #endif
185 
186 /*
187  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
188  * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
189  * and there are 16 of them to cover all possible combinations of
190  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
191  *
192  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
193  * But GFP_MOVABLE is not only a zone specifier but also an allocation
194  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
195  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
196  *
197  *       bit       result
198  *       =================
199  *       0x0    => NORMAL
200  *       0x1    => DMA or NORMAL
201  *       0x2    => HIGHMEM or NORMAL
202  *       0x3    => BAD (DMA+HIGHMEM)
203  *       0x4    => DMA32 or DMA or NORMAL
204  *       0x5    => BAD (DMA+DMA32)
205  *       0x6    => BAD (HIGHMEM+DMA32)
206  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
207  *       0x8    => NORMAL (MOVABLE+0)
208  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
209  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
210  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
211  *       0xc    => DMA32 (MOVABLE+DMA32)
212  *       0xd    => BAD (MOVABLE+DMA32+DMA)
213  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
214  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
215  *
216  * ZONES_SHIFT must be <= 2 on 32 bit platforms.
217  */
218 
219 #if 16 * ZONES_SHIFT > BITS_PER_LONG
220 #error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
221 #endif
222 
223 #define GFP_ZONE_TABLE ( \
224         (ZONE_NORMAL << 0 * ZONES_SHIFT)                                      \
225         | (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT)                          \
226         | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT)                  \
227         | (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT)                      \
228         | (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT)                       \
229         | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT)       \
230         | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT)   \
231         | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT)   \
232 )
233 
234 /*
235  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
236  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
237  * entry starting with bit 0. Bit is set if the combination is not
238  * allowed.
239  */
240 #define GFP_ZONE_BAD ( \
241         1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
242         | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
243         | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
244         | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
245         | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
246         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
247         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
248         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
249 )
250 
251 static inline enum zone_type gfp_zone(gfp_t flags)
252 {
253         enum zone_type z;
254         int bit = (__force int) (flags & GFP_ZONEMASK);
255 
256         z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
257                                          ((1 << ZONES_SHIFT) - 1);
258         VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
259         return z;
260 }
261 
262 /*
263  * There is only one page-allocator function, and two main namespaces to
264  * it. The alloc_page*() variants return 'struct page *' and as such
265  * can allocate highmem pages, the *get*page*() variants return
266  * virtual kernel addresses to the allocated page(s).
267  */
268 
269 static inline int gfp_zonelist(gfp_t flags)
270 {
271         if (IS_ENABLED(CONFIG_NUMA) && unlikely(flags & __GFP_THISNODE))
272                 return 1;
273 
274         return 0;
275 }
276 
277 /*
278  * We get the zone list from the current node and the gfp_mask.
279  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
280  * There are two zonelists per node, one for all zones with memory and
281  * one containing just zones from the node the zonelist belongs to.
282  *
283  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
284  * optimized to &contig_page_data at compile-time.
285  */
286 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
287 {
288         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
289 }
290 
291 #ifndef HAVE_ARCH_FREE_PAGE
292 static inline void arch_free_page(struct page *page, int order) { }
293 #endif
294 #ifndef HAVE_ARCH_ALLOC_PAGE
295 static inline void arch_alloc_page(struct page *page, int order) { }
296 #endif
297 
298 struct page *
299 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
300                        struct zonelist *zonelist, nodemask_t *nodemask);
301 
302 static inline struct page *
303 __alloc_pages(gfp_t gfp_mask, unsigned int order,
304                 struct zonelist *zonelist)
305 {
306         return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
307 }
308 
309 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
310                                                 unsigned int order)
311 {
312         /* Unknown node is current node */
313         if (nid < 0)
314                 nid = numa_node_id();
315 
316         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
317 }
318 
319 static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask,
320                                                 unsigned int order)
321 {
322         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid));
323 
324         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
325 }
326 
327 #ifdef CONFIG_NUMA
328 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
329 
330 static inline struct page *
331 alloc_pages(gfp_t gfp_mask, unsigned int order)
332 {
333         return alloc_pages_current(gfp_mask, order);
334 }
335 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
336                         struct vm_area_struct *vma, unsigned long addr,
337                         int node, bool hugepage);
338 #define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
339         alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
340 #else
341 #define alloc_pages(gfp_mask, order) \
342                 alloc_pages_node(numa_node_id(), gfp_mask, order)
343 #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
344         alloc_pages(gfp_mask, order)
345 #define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
346         alloc_pages(gfp_mask, order)
347 #endif
348 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
349 #define alloc_page_vma(gfp_mask, vma, addr)                     \
350         alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
351 #define alloc_page_vma_node(gfp_mask, vma, addr, node)          \
352         alloc_pages_vma(gfp_mask, 0, vma, addr, node, false)
353 
354 extern struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order);
355 extern struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask,
356                                           unsigned int order);
357 
358 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
359 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
360 
361 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
362 void free_pages_exact(void *virt, size_t size);
363 /* This is different from alloc_pages_exact_node !!! */
364 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
365 
366 #define __get_free_page(gfp_mask) \
367                 __get_free_pages((gfp_mask), 0)
368 
369 #define __get_dma_pages(gfp_mask, order) \
370                 __get_free_pages((gfp_mask) | GFP_DMA, (order))
371 
372 extern void __free_pages(struct page *page, unsigned int order);
373 extern void free_pages(unsigned long addr, unsigned int order);
374 extern void free_hot_cold_page(struct page *page, bool cold);
375 extern void free_hot_cold_page_list(struct list_head *list, bool cold);
376 
377 extern void __free_kmem_pages(struct page *page, unsigned int order);
378 extern void free_kmem_pages(unsigned long addr, unsigned int order);
379 
380 #define __free_page(page) __free_pages((page), 0)
381 #define free_page(addr) free_pages((addr), 0)
382 
383 void page_alloc_init(void);
384 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
385 void drain_all_pages(struct zone *zone);
386 void drain_local_pages(struct zone *zone);
387 
388 /*
389  * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
390  * GFP flags are used before interrupts are enabled. Once interrupts are
391  * enabled, it is set to __GFP_BITS_MASK while the system is running. During
392  * hibernation, it is used by PM to avoid I/O during memory allocation while
393  * devices are suspended.
394  */
395 extern gfp_t gfp_allowed_mask;
396 
397 /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
398 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
399 
400 extern void pm_restrict_gfp_mask(void);
401 extern void pm_restore_gfp_mask(void);
402 
403 #ifdef CONFIG_PM_SLEEP
404 extern bool pm_suspended_storage(void);
405 #else
406 static inline bool pm_suspended_storage(void)
407 {
408         return false;
409 }
410 #endif /* CONFIG_PM_SLEEP */
411 
412 #ifdef CONFIG_CMA
413 
414 /* The below functions must be run on a range from a single zone. */
415 extern int alloc_contig_range(unsigned long start, unsigned long end,
416                               unsigned migratetype);
417 extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
418 
419 /* CMA stuff */
420 extern void init_cma_reserved_pageblock(struct page *page);
421 
422 #endif
423 
424 #endif /* __LINUX_GFP_H */
425 

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