LXR linux/include/rdma/uverbs

   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
  12struct uverbs_obj_type;
  13struct uverbs_api_object;
  14
  15enum 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 */
  57struct 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        void (*swap_uobjects)(struct ib_uobject *obj_old,
  75                              struct ib_uobject *obj_new);
  76};
  77
  78struct uverbs_obj_type {
  79        const struct uverbs_obj_type_class * const type_class;
  80        size_t       obj_size;
  81};
  82
  83/*
  84 * Objects type classes which support a detach state (object is still alive but
  85 * it's not attached to any context need to make sure:
  86 * (a) no call through to a driver after a detach is called
  87 * (b) detach isn't called concurrently with context_cleanup
  88 */
  89
  90struct uverbs_obj_idr_type {
  91        /*
  92         * In idr based objects, uverbs_obj_type_class points to a generic
  93         * idr operations. In order to specialize the underlying types (e.g. CQ,
  94         * QPs, etc.), we add destroy_object specific callbacks.
  95         */
  96        struct uverbs_obj_type  type;
  97
  98        /* Free driver resources from the uobject, make the driver uncallable,
  99         * and move the uobject to the detached state. If the object was
 100         * destroyed by the user's request, a failure should leave the uobject
 101         * completely unchanged.
 102         */
 103        int __must_check (*destroy_object)(struct ib_uobject *uobj,
 104                                           enum rdma_remove_reason why,
 105                                           struct uverbs_attr_bundle *attrs);
 106};
 107
 108struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_api_object *obj,
 109                                           struct ib_uverbs_file *ufile, s64 id,
 110                                           enum rdma_lookup_mode mode,
 111                                           struct uverbs_attr_bundle *attrs);
 112void rdma_lookup_put_uobject(struct ib_uobject *uobj,
 113                             enum rdma_lookup_mode mode);
 114struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
 115                                            struct uverbs_attr_bundle *attrs);
 116void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
 117                              struct uverbs_attr_bundle *attrs,
 118                              bool hw_obj_valid);
 119void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
 120                               struct uverbs_attr_bundle *attrs);
 121void rdma_assign_uobject(struct ib_uobject *to_uobj,
 122                         struct ib_uobject *new_uobj,
 123                         struct uverbs_attr_bundle *attrs);
 124
 125/*
 126 * uverbs_uobject_get is called in order to increase the reference count on
 127 * an uobject. This is useful when a handler wants to keep the uobject's memory
 128 * alive, regardless if this uobject is still alive in the context's objects
 129 * repository. Objects are put via uverbs_uobject_put.
 130 */
 131static inline void uverbs_uobject_get(struct ib_uobject *uobject)
 132{
 133        kref_get(&uobject->ref);
 134}
 135void uverbs_uobject_put(struct ib_uobject *uobject);
 136
 137struct uverbs_obj_fd_type {
 138        /*
 139         * In fd based objects, uverbs_obj_type_ops points to generic
 140         * fd operations. In order to specialize the underlying types (e.g.
 141         * completion_channel), we use fops, name and flags for fd creation.
 142         * destroy_object is called when the uobject is to be destroyed,
 143         * because the driver is removed or the FD is closed.
 144         */
 145        struct uverbs_obj_type  type;
 146        void (*destroy_object)(struct ib_uobject *uobj,
 147                               enum rdma_remove_reason why);
 148        const struct file_operations    *fops;
 149        const char                      *name;
 150        int                             flags;
 151};
 152
 153extern const struct uverbs_obj_type_class uverbs_idr_class;
 154extern const struct uverbs_obj_type_class uverbs_fd_class;
 155int uverbs_uobject_fd_release(struct inode *inode, struct file *filp);
 156
 157#define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) -     \
 158                                   sizeof(char))
 159#define UVERBS_TYPE_ALLOC_FD(_obj_size, _destroy_object, _fops, _name, _flags) \
 160        ((&((const struct uverbs_obj_fd_type)                           \
 161         {.type = {                                                     \
 162                .type_class = &uverbs_fd_class,                         \
 163                .obj_size = (_obj_size) +                               \
 164                        UVERBS_BUILD_BUG_ON((_obj_size) <               \
 165                                            sizeof(struct ib_uobject)), \
 166         },                                                             \
 167         .destroy_object = _destroy_object,                             \
 168         .fops = _fops,                                                 \
 169         .name = _name,                                                 \
 170         .flags = _flags}))->type)
 171#define UVERBS_TYPE_ALLOC_IDR_SZ(_size, _destroy_object)        \
 172        ((&((const struct uverbs_obj_idr_type)                          \
 173         {.type = {                                                     \
 174                .type_class = &uverbs_idr_class,                        \
 175                .obj_size = (_size) +                                   \
 176                        UVERBS_BUILD_BUG_ON((_size) <                   \
 177                                            sizeof(struct ib_uobject))  \
 178         },                                                             \
 179         .destroy_object = _destroy_object,}))->type)
 180#define UVERBS_TYPE_ALLOC_IDR(_destroy_object)                  \
 181         UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_uobject),    \
 182                                  _destroy_object)
 183
 184#endif
 185