include/rdma/uverbs_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
   2 /*
   3  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
   4  */
   5
   6 #ifndef _UVERBS_TYPES_
   7 #define _UVERBS_TYPES_
   8
   9 #include <linux/kernel.h>
  10 #include <rdma/ib_verbs.h>
  11
  12 struct uverbs_obj_type;
  13 struct uverbs_api_object;
  14
  15 enum rdma_lookup_mode {
  16         UVERBS_LOOKUP_READ,
  17         UVERBS_LOOKUP_WRITE,
  18         /*
  19          * Destroy is like LOOKUP_WRITE, except that the uobject is not
  20          * locked.  uobj_destroy is used to convert a LOOKUP_DESTROY lock into
  21          * a LOOKUP_WRITE lock.
  22          */
  23         UVERBS_LOOKUP_DESTROY,
  24 };
  25
  26 /*
  27  * The following sequences are valid:
  28  * Success flow:
  29  *   alloc_begin
  30  *   alloc_commit
  31  *    [..]
  32  * Access flow:
  33  *   lookup_get(exclusive=false) & uverbs_try_lock_object
  34  *   lookup_put(exclusive=false) via rdma_lookup_put_uobject
  35  * Destruction flow:
  36  *   lookup_get(exclusive=true) & uverbs_try_lock_object
  37  *   remove_commit
  38  *   remove_handle (optional)
  39  *   lookup_put(exclusive=true) via rdma_lookup_put_uobject
  40  *
  41  * Allocate Error flow #1
  42  *   alloc_begin
  43  *   alloc_abort
  44  * Allocate Error flow #2
  45  *   alloc_begin
  46  *   remove_commit
  47  *   alloc_abort
  48  * Allocate Error flow #3
  49  *   alloc_begin
  50  *   alloc_commit (fails)
  51  *   remove_commit
  52  *   alloc_abort
  53  *
  54  * In all cases the caller must hold the ufile kref until alloc_commit or
  55  * alloc_abort returns.
  56  */
  57 struct uverbs_obj_type_class {
  58         struct ib_uobject *(*alloc_begin)(const struct uverbs_api_object *obj,
  59                                           struct uverbs_attr_bundle *attrs);
  60         /* This consumes the kref on uobj */
  61         void (*alloc_commit)(struct ib_uobject *uobj);
  62         /* This does not consume the kref on uobj */
  63         void (*alloc_abort)(struct ib_uobject *uobj);
  64
  65         struct ib_uobject *(*lookup_get)(const struct uverbs_api_object *obj,
  66                                          struct ib_uverbs_file *ufile, s64 id,
  67                                          enum rdma_lookup_mode mode);
  68         void (*lookup_put)(struct ib_uobject *uobj, enum rdma_lookup_mode mode);
  69         /* This does not consume the kref on uobj */
  70         int __must_check (*destroy_hw)(struct ib_uobject *uobj,
  71                                        enum rdma_remove_reason why,
  72                                        struct uverbs_attr_bundle *attrs);
  73         void (*remove_handle)(struct ib_uobject *uobj);
  74 };
  75
  76 struct uverbs_obj_type {
  77         const struct uverbs_obj_type_class * const type_class;
  78         size_t       obj_size;
  79 };
  80
  81 /*
  82  * Objects type classes which support a detach state (object is still alive but
  83  * it's not attached to any context need to make sure:
  84  * (a) no call through to a driver after a detach is called
  85  * (b) detach isn't called concurrently with context_cleanup
  86  */
  87
  88 struct uverbs_obj_idr_type {
  89         /*
  90          * In idr based objects, uverbs_obj_type_class points to a generic
  91          * idr operations. In order to specialize the underlying types (e.g. CQ,
  92          * QPs, etc.), we add destroy_object specific callbacks.
  93          */
  94         struct uverbs_obj_type  type;
  95
  96         /* Free driver resources from the uobject, make the driver uncallable,
  97          * and move the uobject to the detached state. If the object was
  98          * destroyed by the user's request, a failure should leave the uobject
  99          * completely unchanged.
 100          */
 101         int __must_check (*destroy_object)(struct ib_uobject *uobj,
 102                                            enum rdma_remove_reason why,
 103                                            struct uverbs_attr_bundle *attrs);
 104 };
 105
 106 struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_api_object *obj,
 107                                            struct ib_uverbs_file *ufile, s64 id,
 108                                            enum rdma_lookup_mode mode,
 109                                            struct uverbs_attr_bundle *attrs);
 110 void rdma_lookup_put_uobject(struct ib_uobject *uobj,
 111                              enum rdma_lookup_mode mode);
 112 struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
 113                                             struct uverbs_attr_bundle *attrs);
 114 void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
 115                               struct uverbs_attr_bundle *attrs,
 116                               bool hw_obj_valid);
 117 void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
 118                                struct uverbs_attr_bundle *attrs);
 119
 120 /*
 121  * uverbs_uobject_get is called in order to increase the reference count on
 122  * an uobject. This is useful when a handler wants to keep the uobject's memory
 123  * alive, regardless if this uobject is still alive in the context's objects
 124  * repository. Objects are put via uverbs_uobject_put.
 125  */
 126 static inline void uverbs_uobject_get(struct ib_uobject *uobject)
 127 {
 128         kref_get(&uobject->ref);
 129 }
 130 void uverbs_uobject_put(struct ib_uobject *uobject);
 131
 132 struct uverbs_obj_fd_type {
 133         /*
 134          * In fd based objects, uverbs_obj_type_ops points to generic
 135          * fd operations. In order to specialize the underlying types (e.g.
 136          * completion_channel), we use fops, name and flags for fd creation.
 137          * destroy_object is called when the uobject is to be destroyed,
 138          * because the driver is removed or the FD is closed.
 139          */
 140         struct uverbs_obj_type  type;
 141         int (*destroy_object)(struct ib_uobject *uobj,
 142                               enum rdma_remove_reason why);
 143         const struct file_operations    *fops;
 144         const char                      *name;
 145         int                             flags;
 146 };
 147
 148 extern const struct uverbs_obj_type_class uverbs_idr_class;
 149 extern const struct uverbs_obj_type_class uverbs_fd_class;
 150 int uverbs_uobject_fd_release(struct inode *inode, struct file *filp);
 151
 152 #define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) -     \
 153                                    sizeof(char))
 154 #define UVERBS_TYPE_ALLOC_FD(_obj_size, _destroy_object, _fops, _name, _flags) \
 155         ((&((const struct uverbs_obj_fd_type)                           \
 156          {.type = {                                                     \
 157                 .type_class = &uverbs_fd_class,                         \
 158                 .obj_size = (_obj_size) +                               \
 159                         UVERBS_BUILD_BUG_ON((_obj_size) <               \
 160                                             sizeof(struct ib_uobject)), \
 161          },                                                             \
 162          .destroy_object = _destroy_object,                             \
 163          .fops = _fops,                                                 \
 164          .name = _name,                                                 \
 165          .flags = _flags}))->type)
 166 #define UVERBS_TYPE_ALLOC_IDR_SZ(_size, _destroy_object)        \
 167         ((&((const struct uverbs_obj_idr_type)                          \
 168          {.type = {                                                     \
 169                 .type_class = &uverbs_idr_class,                        \
 170                 .obj_size = (_size) +                                   \
 171                         UVERBS_BUILD_BUG_ON((_size) <                   \
 172                                             sizeof(struct ib_uobject))  \
 173          },                                                             \
 174          .destroy_object = _destroy_object,}))->type)
 175 #define UVERBS_TYPE_ALLOC_IDR(_destroy_object)                  \
 176          UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_uobject),    \
 177                                   _destroy_object)
 178
 179 #endif