xref: /openbmc/linux/fs/xfs/kmem.h (revision 6e6faf7a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #ifndef __XFS_SUPPORT_KMEM_H__
7 #define __XFS_SUPPORT_KMEM_H__
8 
9 #include <linux/slab.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12 #include <linux/vmalloc.h>
13 
14 /*
15  * General memory allocation interfaces
16  */
17 
18 typedef unsigned __bitwise xfs_km_flags_t;
19 #define KM_NOFS		((__force xfs_km_flags_t)0x0004u)
20 #define KM_MAYFAIL	((__force xfs_km_flags_t)0x0008u)
21 #define KM_ZERO		((__force xfs_km_flags_t)0x0010u)
22 #define KM_NOLOCKDEP	((__force xfs_km_flags_t)0x0020u)
23 
24 /*
25  * We use a special process flag to avoid recursive callbacks into
26  * the filesystem during transactions.  We will also issue our own
27  * warnings, so we explicitly skip any generic ones (silly of us).
28  */
29 static inline gfp_t
30 kmem_flags_convert(xfs_km_flags_t flags)
31 {
32 	gfp_t	lflags;
33 
34 	BUG_ON(flags & ~(KM_NOFS | KM_MAYFAIL | KM_ZERO | KM_NOLOCKDEP));
35 
36 	lflags = GFP_KERNEL | __GFP_NOWARN;
37 	if (flags & KM_NOFS)
38 		lflags &= ~__GFP_FS;
39 
40 	/*
41 	 * Default page/slab allocator behavior is to retry for ever
42 	 * for small allocations. We can override this behavior by using
43 	 * __GFP_RETRY_MAYFAIL which will tell the allocator to retry as long
44 	 * as it is feasible but rather fail than retry forever for all
45 	 * request sizes.
46 	 */
47 	if (flags & KM_MAYFAIL)
48 		lflags |= __GFP_RETRY_MAYFAIL;
49 
50 	if (flags & KM_ZERO)
51 		lflags |= __GFP_ZERO;
52 
53 	if (flags & KM_NOLOCKDEP)
54 		lflags |= __GFP_NOLOCKDEP;
55 
56 	return lflags;
57 }
58 
59 extern void *kmem_alloc(size_t, xfs_km_flags_t);
60 static inline void  kmem_free(const void *ptr)
61 {
62 	kvfree(ptr);
63 }
64 
65 
66 static inline void *
67 kmem_zalloc(size_t size, xfs_km_flags_t flags)
68 {
69 	return kmem_alloc(size, flags | KM_ZERO);
70 }
71 
72 /*
73  * Zone interfaces
74  */
75 static inline struct page *
76 kmem_to_page(void *addr)
77 {
78 	if (is_vmalloc_addr(addr))
79 		return vmalloc_to_page(addr);
80 	return virt_to_page(addr);
81 }
82 
83 #endif /* __XFS_SUPPORT_KMEM_H__ */
84