include/os/linux/kernel/linux/mod_compat.h

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