xref: /freebsd/sys/contrib/openzfs/include/os/linux/kernel/linux/mod_compat.h (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright (C) 2016 Gvozden Neskovic <neskovic@gmail.com>.
25  * Copyright (c) 2020 by Delphix. All rights reserved.
26  */
27 
28 #ifndef _MOD_COMPAT_H
29 #define	_MOD_COMPAT_H
30 
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 
34 /*
35  * Despite constifying struct kernel_param_ops, some older kernels define a
36  * `__check_old_set_param()` function in their headers that checks for a
37  * non-constified `->set()`. This has long been fixed in Linux mainline, but
38  * since we support older kernels, we workaround it by using a preprocessor
39  * definition to disable it.
40  */
41 #define	__check_old_set_param(_) (0)
42 
43 typedef const struct kernel_param zfs_kernel_param_t;
44 
45 #define	ZMOD_RW 0644
46 #define	ZMOD_RD 0444
47 
48 enum scope_prefix_types {
49 	zfs,
50 	zfs_arc,
51 	zfs_brt,
52 	zfs_condense,
53 	zfs_dbuf,
54 	zfs_dbuf_cache,
55 	zfs_deadman,
56 	zfs_dedup,
57 	zfs_l2arc,
58 	zfs_livelist,
59 	zfs_livelist_condense,
60 	zfs_lua,
61 	zfs_metaslab,
62 	zfs_mg,
63 	zfs_multihost,
64 	zfs_prefetch,
65 	zfs_reconstruct,
66 	zfs_recv,
67 	zfs_send,
68 	zfs_spa,
69 	zfs_trim,
70 	zfs_txg,
71 	zfs_vdev,
72 	zfs_vdev_disk,
73 	zfs_vdev_file,
74 	zfs_vdev_mirror,
75 	zfs_vnops,
76 	zfs_zevent,
77 	zfs_zio,
78 	zfs_zil
79 };
80 
81 /*
82  * While we define our own s64/u64 types, there is no reason to reimplement the
83  * existing Linux kernel types, so we use the preprocessor to remap our
84  * "custom" implementations to the kernel ones. This is done because the CPP
85  * does not allow us to write conditional definitions. The fourth definition
86  * exists because the CPP will not allow us to replace things like INT with int
87  * before string concatenation.
88  */
89 
90 #define	spl_param_set_int param_set_int
91 #define	spl_param_get_int param_get_int
92 #define	spl_param_ops_int param_ops_int
93 #define	spl_param_ops_INT param_ops_int
94 
95 #define	spl_param_set_long param_set_long
96 #define	spl_param_get_long param_get_long
97 #define	spl_param_ops_long param_ops_long
98 #define	spl_param_ops_LONG param_ops_long
99 
100 #define	spl_param_set_uint param_set_uint
101 #define	spl_param_get_uint param_get_uint
102 #define	spl_param_ops_uint param_ops_uint
103 #define	spl_param_ops_UINT param_ops_uint
104 
105 #define	spl_param_set_ulong param_set_ulong
106 #define	spl_param_get_ulong param_get_ulong
107 #define	spl_param_ops_ulong param_ops_ulong
108 #define	spl_param_ops_ULONG param_ops_ulong
109 
110 #define	spl_param_set_charp param_set_charp
111 #define	spl_param_get_charp param_get_charp
112 #define	spl_param_ops_charp param_ops_charp
113 #define	spl_param_ops_STRING param_ops_charp
114 
115 int spl_param_set_s64(const char *val, zfs_kernel_param_t *kp);
116 extern int spl_param_get_s64(char *buffer, zfs_kernel_param_t *kp);
117 extern const struct kernel_param_ops spl_param_ops_s64;
118 #define	spl_param_ops_S64 spl_param_ops_s64
119 
120 extern int spl_param_set_u64(const char *val, zfs_kernel_param_t *kp);
121 extern int spl_param_get_u64(char *buffer, zfs_kernel_param_t *kp);
122 extern const struct kernel_param_ops spl_param_ops_u64;
123 #define	spl_param_ops_U64 spl_param_ops_u64
124 
125 /*
126  * Declare a module parameter / sysctl node
127  *
128  * "scope_prefix" the part of the sysctl / sysfs tree the node resides under
129  *   (currently a no-op on Linux)
130  * "name_prefix" the part of the variable name that will be excluded from the
131  *   exported names on platforms with a hierarchical namespace
132  * "name" the part of the variable that will be exposed on platforms with a
133  *    hierarchical namespace, or as name_prefix ## name on Linux
134  * "type" the variable type
135  * "perm" the permissions (read/write or read only)
136  * "desc" a brief description of the option
137  *
138  * Examples:
139  * ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, rotating_inc, UINT,
140  * 	ZMOD_RW, "Rotating media load increment for non-seeking I/O's");
141  * on FreeBSD:
142  *   vfs.zfs.vdev.mirror.rotating_inc
143  * on Linux:
144  *   zfs_vdev_mirror_rotating_inc
145  *
146  * ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, UINT, ZMOD_RW,
147  * 	"Limit one prefetch call to this size");
148  * on FreeBSD:
149  *   vfs.zfs.dmu_prefetch_max
150  * on Linux:
151  *   dmu_prefetch_max
152  */
153 #define	ZFS_MODULE_PARAM(scope_prefix, name_prefix, name, type, perm, desc) \
154 	_Static_assert( \
155 	    sizeof (scope_prefix) == sizeof (enum scope_prefix_types), \
156 	    "" #scope_prefix " size mismatch with enum scope_prefix_types"); \
157 	module_param_cb(name_prefix ## name, &spl_param_ops_ ## type, \
158 	    &name_prefix ## name, perm); \
159 	MODULE_PARM_DESC(name_prefix ## name, desc)
160 
161 /*
162  * Declare a module parameter / sysctl node
163  *
164  * "scope_prefix" the part of the the sysctl / sysfs tree the node resides under
165  *   (currently a no-op on Linux)
166  * "name_prefix" the part of the variable name that will be excluded from the
167  *   exported names on platforms with a hierarchical namespace
168  * "name" the part of the variable that will be exposed on platforms with a
169  *    hierarchical namespace, or as name_prefix ## name on Linux
170  * "setfunc" setter function
171  * "getfunc" getter function
172  * "perm" the permissions (read/write or read only)
173  * "desc" a brief description of the option
174  *
175  * Examples:
176  * ZFS_MODULE_PARAM_CALL(zfs_spa, spa_, slop_shift, param_set_slop_shift,
177  * 	param_get_int, ZMOD_RW, "Reserved free space in pool");
178  * on FreeBSD:
179  *   vfs.zfs.spa_slop_shift
180  * on Linux:
181  *   spa_slop_shift
182  */
183 #define	ZFS_MODULE_PARAM_CALL( \
184     scope_prefix, name_prefix, name, setfunc, getfunc, perm, desc) \
185 	_Static_assert( \
186 	    sizeof (scope_prefix) == sizeof (enum scope_prefix_types), \
187 	    "" #scope_prefix " size mismatch with enum scope_prefix_types"); \
188 	module_param_call(name_prefix ## name, setfunc, getfunc, \
189 	    &name_prefix ## name, perm); \
190 	MODULE_PARM_DESC(name_prefix ## name, desc)
191 
192 /*
193  * As above, but there is no variable with the name name_prefix ## name,
194  * so NULL is passed to module_param_call instead.
195  */
196 #define	ZFS_MODULE_VIRTUAL_PARAM_CALL( \
197     scope_prefix, name_prefix, name, setfunc, getfunc, perm, desc) \
198 	_Static_assert( \
199 	    sizeof (scope_prefix) == sizeof (enum scope_prefix_types), \
200 	    "" #scope_prefix " size mismatch with enum scope_prefix_types"); \
201 	module_param_call(name_prefix ## name, setfunc, getfunc, NULL, perm); \
202 	MODULE_PARM_DESC(name_prefix ## name, desc)
203 
204 #define	ZFS_MODULE_PARAM_ARGS	const char *buf, zfs_kernel_param_t *kp
205 
206 #endif	/* _MOD_COMPAT_H */
207