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_disk,
  72         zfs_vdev_file,
  73         zfs_vdev_mirror,
  74         zfs_vnops,
  75         zfs_zevent,
  76         zfs_zio,
  77         zfs_zil
  78 };
  79
  80 /*
  81  * While we define our own s64/u64 types, there is no reason to reimplement the
  82  * existing Linux kernel types, so we use the preprocessor to remap our
  83  * "custom" implementations to the kernel ones. This is done because the CPP
  84  * does not allow us to write conditional definitions. The fourth definition
  85  * exists because the CPP will not allow us to replace things like INT with int
  86  * before string concatenation.
  87  */
  88
  89 #define spl_param_set_int param_set_int
  90 #define spl_param_get_int param_get_int
  91 #define spl_param_ops_int param_ops_int
  92 #define spl_param_ops_INT param_ops_int
  93
  94 #define spl_param_set_long param_set_long
  95 #define spl_param_get_long param_get_long
  96 #define spl_param_ops_long param_ops_long
  97 #define spl_param_ops_LONG param_ops_long
  98
  99 #define spl_param_set_uint param_set_uint
 100 #define spl_param_get_uint param_get_uint
 101 #define spl_param_ops_uint param_ops_uint
 102 #define spl_param_ops_UINT param_ops_uint
 103
 104 #define spl_param_set_ulong param_set_ulong
 105 #define spl_param_get_ulong param_get_ulong
 106 #define spl_param_ops_ulong param_ops_ulong
 107 #define spl_param_ops_ULONG param_ops_ulong
 108
 109 #define spl_param_set_charp param_set_charp
 110 #define spl_param_get_charp param_get_charp
 111 #define spl_param_ops_charp param_ops_charp
 112 #define spl_param_ops_STRING param_ops_charp
 113
 114 int spl_param_set_s64(const char *val, zfs_kernel_param_t *kp);
 115 extern int spl_param_get_s64(char *buffer, zfs_kernel_param_t *kp);
 116 extern const struct kernel_param_ops spl_param_ops_s64;
 117 #define spl_param_ops_S64 spl_param_ops_s64
 118
 119 extern int spl_param_set_u64(const char *val, zfs_kernel_param_t *kp);
 120 extern int spl_param_get_u64(char *buffer, zfs_kernel_param_t *kp);
 121 extern const struct kernel_param_ops spl_param_ops_u64;
 122 #define spl_param_ops_U64 spl_param_ops_u64
 123
 124 /*
 125  * Declare a module parameter / sysctl node
 126  *
 127  * "scope_prefix" the part of the sysctl / sysfs tree the node resides under
 128  *   (currently a no-op on Linux)
 129  * "name_prefix" the part of the variable name that will be excluded from the
 130  *   exported names on platforms with a hierarchical namespace
 131  * "name" the part of the variable that will be exposed on platforms with a
 132  *    hierarchical namespace, or as name_prefix ## name on Linux
 133  * "type" the variable type
 134  * "perm" the permissions (read/write or read only)
 135  * "desc" a brief description of the option
 136  *
 137  * Examples:
 138  * ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, rotating_inc, UINT,
 139  *      ZMOD_RW, "Rotating media load increment for non-seeking I/O's");
 140  * on FreeBSD:
 141  *   vfs.zfs.vdev.mirror.rotating_inc
 142  * on Linux:
 143  *   zfs_vdev_mirror_rotating_inc
 144  *
 145  * ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, UINT, ZMOD_RW,
 146  *      "Limit one prefetch call to this size");
 147  * on FreeBSD:
 148  *   vfs.zfs.dmu_prefetch_max
 149  * on Linux:
 150  *   dmu_prefetch_max
 151  */
 152 #define ZFS_MODULE_PARAM(scope_prefix, name_prefix, name, type, perm, desc) \
 153         _Static_assert( \
 154             sizeof (scope_prefix) == sizeof (enum scope_prefix_types), \
 155             "" #scope_prefix " size mismatch with enum scope_prefix_types"); \
 156         module_param_cb(name_prefix ## name, &spl_param_ops_ ## type, \
 157             &name_prefix ## name, perm); \
 158         MODULE_PARM_DESC(name_prefix ## name, desc)
 159
 160 /*
 161  * Declare a module parameter / sysctl node
 162  *
 163  * "scope_prefix" the part of the the sysctl / sysfs tree the node resides under
 164  *   (currently a no-op on Linux)
 165  * "name_prefix" the part of the variable name that will be excluded from the
 166  *   exported names on platforms with a hierarchical namespace
 167  * "name" the part of the variable that will be exposed on platforms with a
 168  *    hierarchical namespace, or as name_prefix ## name on Linux
 169  * "setfunc" setter function
 170  * "getfunc" getter function
 171  * "perm" the permissions (read/write or read only)
 172  * "desc" a brief description of the option
 173  *
 174  * Examples:
 175  * ZFS_MODULE_PARAM_CALL(zfs_spa, spa_, slop_shift, param_set_slop_shift,
 176  *      param_get_int, ZMOD_RW, "Reserved free space in pool");
 177  * on FreeBSD:
 178  *   vfs.zfs.spa_slop_shift
 179  * on Linux:
 180  *   spa_slop_shift
 181  */
 182 #define ZFS_MODULE_PARAM_CALL( \
 183     scope_prefix, name_prefix, name, setfunc, getfunc, perm, desc) \
 184         _Static_assert( \
 185             sizeof (scope_prefix) == sizeof (enum scope_prefix_types), \
 186             "" #scope_prefix " size mismatch with enum scope_prefix_types"); \
 187         module_param_call(name_prefix ## name, setfunc, getfunc, \
 188             &name_prefix ## name, perm); \
 189         MODULE_PARM_DESC(name_prefix ## name, desc)
 190
 191 /*
 192  * As above, but there is no variable with the name name_prefix ## name,
 193  * so NULL is passed to module_param_call instead.
 194  */
 195 #define ZFS_MODULE_VIRTUAL_PARAM_CALL( \
 196     scope_prefix, name_prefix, name, setfunc, getfunc, perm, desc) \
 197         _Static_assert( \
 198             sizeof (scope_prefix) == sizeof (enum scope_prefix_types), \
 199             "" #scope_prefix " size mismatch with enum scope_prefix_types"); \
 200         module_param_call(name_prefix ## name, setfunc, getfunc, NULL, perm); \
 201         MODULE_PARM_DESC(name_prefix ## name, desc)
 202
 203 #define ZFS_MODULE_PARAM_ARGS   const char *buf, zfs_kernel_param_t *kp
 204
 205 #endif  /* _MOD_COMPAT_H */