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};
  75
  76struct 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
  88struct 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
 106struct 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);
 110void rdma_lookup_put_uobject(struct ib_uobject *uobj,
 111                             enum rdma_lookup_mode mode);
 112struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
 113                                            struct uverbs_attr_bundle *attrs);
 114void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
 115                              struct uverbs_attr_bundle *attrs,
 116                              bool hw_obj_valid);
 117void 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 */
 126static inline void uverbs_uobject_get(struct ib_uobject *uobject)
 127{
 128        kref_get(&uobject->ref);
 129}
 130void uverbs_uobject_put(struct ib_uobject *uobject);
 131
 132struct 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
 148extern const struct uverbs_obj_type_class uverbs_idr_class;
 149extern const struct uverbs_obj_type_class uverbs_fd_class;
 150int 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
 180