fs/ntfs/malloc.h

   1 /*
   2  * malloc.h - NTFS kernel memory handling. Part of the Linux-NTFS project.
   3  *
   4  * Copyright (c) 2001-2005 Anton Altaparmakov
   5  *
   6  * This program/include file is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as published
   8  * by the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program/include file is distributed in the hope that it will be
  12  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program (in the main directory of the Linux-NTFS
  18  * distribution in the file COPYING); if not, write to the Free Software
  19  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #ifndef _LINUX_NTFS_MALLOC_H
  23 #define _LINUX_NTFS_MALLOC_H
  24
  25 #include <linux/vmalloc.h>
  26 #include <linux/slab.h>
  27 #include <linux/highmem.h>
  28
  29 /**
  30  * __ntfs_malloc - allocate memory in multiples of pages
  31  * @size:       number of bytes to allocate
  32  * @gfp_mask:   extra flags for the allocator
  33  *
  34  * Internal function.  You probably want ntfs_malloc_nofs()...
  35  *
  36  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
  37  * returns a pointer to the allocated memory.
  38  *
  39  * If there was insufficient memory to complete the request, return NULL.
  40  * Depending on @gfp_mask the allocation may be guaranteed to succeed.
  41  */
  42 static inline void *__ntfs_malloc(unsigned long size,
  43                 gfp_t gfp_mask)
  44 {
  45         if (likely(size <= PAGE_SIZE)) {
  46                 BUG_ON(!size);
  47                 /* kmalloc() has per-CPU caches so is faster for now. */
  48                 return kmalloc(PAGE_SIZE, gfp_mask & ~__GFP_HIGHMEM);
  49                 /* return (void *)__get_free_page(gfp_mask); */
  50         }
  51         if (likely(size >> PAGE_SHIFT < num_physpages))
  52                 return __vmalloc(size, gfp_mask, PAGE_KERNEL);
  53         return NULL;
  54 }
  55
  56 /**
  57  * ntfs_malloc_nofs - allocate memory in multiples of pages
  58  * @size:       number of bytes to allocate
  59  *
  60  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
  61  * returns a pointer to the allocated memory.
  62  *
  63  * If there was insufficient memory to complete the request, return NULL.
  64  */
  65 static inline void *ntfs_malloc_nofs(unsigned long size)
  66 {
  67         return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM);
  68 }
  69
  70 /**
  71  * ntfs_malloc_nofs_nofail - allocate memory in multiples of pages
  72  * @size:       number of bytes to allocate
  73  *
  74  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
  75  * returns a pointer to the allocated memory.
  76  *
  77  * This function guarantees that the allocation will succeed.  It will sleep
  78  * for as long as it takes to complete the allocation.
  79  *
  80  * If there was insufficient memory to complete the request, return NULL.
  81  */
  82 static inline void *ntfs_malloc_nofs_nofail(unsigned long size)
  83 {
  84         return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM | __GFP_NOFAIL);
  85 }
  86
  87 static inline void ntfs_free(void *addr)
  88 {
  89         if (likely(((unsigned long)addr < VMALLOC_START) ||
  90                         ((unsigned long)addr >= VMALLOC_END ))) {
  91                 kfree(addr);
  92                 /* free_page((unsigned long)addr); */
  93                 return;
  94         }
  95         vfree(addr);
  96 }
  97
  98 #endif /* _LINUX_NTFS_MALLOC_H */