include/rdma/uverbs_types.h

   1 /*
   2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #ifndef _UVERBS_TYPES_
  34 #define _UVERBS_TYPES_
  35
  36 #include <linux/kernel.h>
  37 #include <rdma/ib_verbs.h>
  38
  39 struct uverbs_obj_type;
  40 struct uverbs_api_object;
  41
  42 enum rdma_lookup_mode {
  43         UVERBS_LOOKUP_READ,
  44         UVERBS_LOOKUP_WRITE,
  45         /*
  46          * Destroy is like LOOKUP_WRITE, except that the uobject is not
  47          * locked.  uobj_destroy is used to convert a LOOKUP_DESTROY lock into
  48          * a LOOKUP_WRITE lock.
  49          */
  50         UVERBS_LOOKUP_DESTROY,
  51 };
  52
  53 /*
  54  * The following sequences are valid:
  55  * Success flow:
  56  *   alloc_begin
  57  *   alloc_commit
  58  *    [..]
  59  * Access flow:
  60  *   lookup_get(exclusive=false) & uverbs_try_lock_object
  61  *   lookup_put(exclusive=false) via rdma_lookup_put_uobject
  62  * Destruction flow:
  63  *   lookup_get(exclusive=true) & uverbs_try_lock_object
  64  *   remove_commit
  65  *   remove_handle (optional)
  66  *   lookup_put(exclusive=true) via rdma_lookup_put_uobject
  67  *
  68  * Allocate Error flow #1
  69  *   alloc_begin
  70  *   alloc_abort
  71  * Allocate Error flow #2
  72  *   alloc_begin
  73  *   remove_commit
  74  *   alloc_abort
  75  * Allocate Error flow #3
  76  *   alloc_begin
  77  *   alloc_commit (fails)
  78  *   remove_commit
  79  *   alloc_abort
  80  *
  81  * In all cases the caller must hold the ufile kref until alloc_commit or
  82  * alloc_abort returns.
  83  */
  84 struct uverbs_obj_type_class {
  85         struct ib_uobject *(*alloc_begin)(const struct uverbs_api_object *obj,
  86                                           struct uverbs_attr_bundle *attrs);
  87         /* This consumes the kref on uobj */
  88         void (*alloc_commit)(struct ib_uobject *uobj);
  89         /* This does not consume the kref on uobj */
  90         void (*alloc_abort)(struct ib_uobject *uobj);
  91
  92         struct ib_uobject *(*lookup_get)(const struct uverbs_api_object *obj,
  93                                          struct ib_uverbs_file *ufile, s64 id,
  94                                          enum rdma_lookup_mode mode);
  95         void (*lookup_put)(struct ib_uobject *uobj, enum rdma_lookup_mode mode);
  96         /* This does not consume the kref on uobj */
  97         int __must_check (*destroy_hw)(struct ib_uobject *uobj,
  98                                        enum rdma_remove_reason why,
  99                                        struct uverbs_attr_bundle *attrs);
 100         void (*remove_handle)(struct ib_uobject *uobj);
 101 };
 102
 103 struct uverbs_obj_type {
 104         const struct uverbs_obj_type_class * const type_class;
 105         size_t       obj_size;
 106 };
 107
 108 /*
 109  * Objects type classes which support a detach state (object is still alive but
 110  * it's not attached to any context need to make sure:
 111  * (a) no call through to a driver after a detach is called
 112  * (b) detach isn't called concurrently with context_cleanup
 113  */
 114
 115 struct uverbs_obj_idr_type {
 116         /*
 117          * In idr based objects, uverbs_obj_type_class points to a generic
 118          * idr operations. In order to specialize the underlying types (e.g. CQ,
 119          * QPs, etc.), we add destroy_object specific callbacks.
 120          */
 121         struct uverbs_obj_type  type;
 122
 123         /* Free driver resources from the uobject, make the driver uncallable,
 124          * and move the uobject to the detached state. If the object was
 125          * destroyed by the user's request, a failure should leave the uobject
 126          * completely unchanged.
 127          */
 128         int __must_check (*destroy_object)(struct ib_uobject *uobj,
 129                                            enum rdma_remove_reason why,
 130                                            struct uverbs_attr_bundle *attrs);
 131 };
 132
 133 struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_api_object *obj,
 134                                            struct ib_uverbs_file *ufile, s64 id,
 135                                            enum rdma_lookup_mode mode,
 136                                            struct uverbs_attr_bundle *attrs);
 137 void rdma_lookup_put_uobject(struct ib_uobject *uobj,
 138                              enum rdma_lookup_mode mode);
 139 struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
 140                                             struct uverbs_attr_bundle *attrs);
 141 void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
 142                               struct uverbs_attr_bundle *attrs);
 143 void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
 144                                struct uverbs_attr_bundle *attrs);
 145
 146 /*
 147  * uverbs_uobject_get is called in order to increase the reference count on
 148  * an uobject. This is useful when a handler wants to keep the uobject's memory
 149  * alive, regardless if this uobject is still alive in the context's objects
 150  * repository. Objects are put via uverbs_uobject_put.
 151  */
 152 static inline void uverbs_uobject_get(struct ib_uobject *uobject)
 153 {
 154         kref_get(&uobject->ref);
 155 }
 156 void uverbs_uobject_put(struct ib_uobject *uobject);
 157
 158 struct uverbs_obj_fd_type {
 159         /*
 160          * In fd based objects, uverbs_obj_type_ops points to generic
 161          * fd operations. In order to specialize the underlying types (e.g.
 162          * completion_channel), we use fops, name and flags for fd creation.
 163          * destroy_object is called when the uobject is to be destroyed,
 164          * because the driver is removed or the FD is closed.
 165          */
 166         struct uverbs_obj_type  type;
 167         int (*destroy_object)(struct ib_uobject *uobj,
 168                               enum rdma_remove_reason why);
 169         const struct file_operations    *fops;
 170         const char                      *name;
 171         int                             flags;
 172 };
 173
 174 extern const struct uverbs_obj_type_class uverbs_idr_class;
 175 extern const struct uverbs_obj_type_class uverbs_fd_class;
 176 int uverbs_uobject_fd_release(struct inode *inode, struct file *filp);
 177
 178 #define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) -     \
 179                                    sizeof(char))
 180 #define UVERBS_TYPE_ALLOC_FD(_obj_size, _destroy_object, _fops, _name, _flags) \
 181         ((&((const struct uverbs_obj_fd_type)                           \
 182          {.type = {                                                     \
 183                 .type_class = &uverbs_fd_class,                         \
 184                 .obj_size = (_obj_size) +                               \
 185                         UVERBS_BUILD_BUG_ON((_obj_size) <               \
 186                                             sizeof(struct ib_uobject)), \
 187          },                                                             \
 188          .destroy_object = _destroy_object,                             \
 189          .fops = _fops,                                                 \
 190          .name = _name,                                                 \
 191          .flags = _flags}))->type)
 192 #define UVERBS_TYPE_ALLOC_IDR_SZ(_size, _destroy_object)        \
 193         ((&((const struct uverbs_obj_idr_type)                          \
 194          {.type = {                                                     \
 195                 .type_class = &uverbs_idr_class,                        \
 196                 .obj_size = (_size) +                                   \
 197                         UVERBS_BUILD_BUG_ON((_size) <                   \
 198                                             sizeof(struct ib_uobject))  \
 199          },                                                             \
 200          .destroy_object = _destroy_object,}))->type)
 201 #define UVERBS_TYPE_ALLOC_IDR(_destroy_object)                  \
 202          UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_uobject),    \
 203                                   _destroy_object)
 204
 205 #endif