fs/ntfs/malloc.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  * malloc.h - NTFS kernel memory handling. Part of the Linux-NTFS project.
0004  *
0005  * Copyright (c) 2001-2005 Anton Altaparmakov
0006  */
0007
0008 #ifndef _LINUX_NTFS_MALLOC_H
0009 #define _LINUX_NTFS_MALLOC_H
0010
0011 #include <linux/vmalloc.h>
0012 #include <linux/slab.h>
0013 #include <linux/highmem.h>
0014
0015 /**
0016  * __ntfs_malloc - allocate memory in multiples of pages
0017  * @size:   number of bytes to allocate
0018  * @gfp_mask:   extra flags for the allocator
0019  *
0020  * Internal function.  You probably want ntfs_malloc_nofs()...
0021  *
0022  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
0023  * returns a pointer to the allocated memory.
0024  *
0025  * If there was insufficient memory to complete the request, return NULL.
0026  * Depending on @gfp_mask the allocation may be guaranteed to succeed.
0027  */
0028 static inline void *__ntfs_malloc(unsigned long size, gfp_t gfp_mask)
0029 {
0030     if (likely(size <= PAGE_SIZE)) {
0031         BUG_ON(!size);
0032         /* kmalloc() has per-CPU caches so is faster for now. */
0033         return kmalloc(PAGE_SIZE, gfp_mask & ~__GFP_HIGHMEM);
0034         /* return (void *)__get_free_page(gfp_mask); */
0035     }
0036     if (likely((size >> PAGE_SHIFT) < totalram_pages()))
0037         return __vmalloc(size, gfp_mask);
0038     return NULL;
0039 }
0040
0041 /**
0042  * ntfs_malloc_nofs - allocate memory in multiples of pages
0043  * @size:   number of bytes to allocate
0044  *
0045  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
0046  * returns a pointer to the allocated memory.
0047  *
0048  * If there was insufficient memory to complete the request, return NULL.
0049  */
0050 static inline void *ntfs_malloc_nofs(unsigned long size)
0051 {
0052     return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM);
0053 }
0054
0055 /**
0056  * ntfs_malloc_nofs_nofail - allocate memory in multiples of pages
0057  * @size:   number of bytes to allocate
0058  *
0059  * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
0060  * returns a pointer to the allocated memory.
0061  *
0062  * This function guarantees that the allocation will succeed.  It will sleep
0063  * for as long as it takes to complete the allocation.
0064  *
0065  * If there was insufficient memory to complete the request, return NULL.
0066  */
0067 static inline void *ntfs_malloc_nofs_nofail(unsigned long size)
0068 {
0069     return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM | __GFP_NOFAIL);
0070 }
0071
0072 static inline void ntfs_free(void *addr)
0073 {
0074     kvfree(addr);
0075 }
0076
0077 #endif /* _LINUX_NTFS_MALLOC_H */