LXR linux/include/rdma/restrack.h

   1/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
   2/*
   3 * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
   4 */
   5
   6#ifndef _RDMA_RESTRACK_H_
   7#define _RDMA_RESTRACK_H_
   8
   9#include <linux/typecheck.h>
  10#include <linux/rwsem.h>
  11#include <linux/sched.h>
  12#include <linux/kref.h>
  13#include <linux/completion.h>
  14
  15/**
  16 * enum rdma_restrack_type - HW objects to track
  17 */
  18enum rdma_restrack_type {
  19        /**
  20         * @RDMA_RESTRACK_PD: Protection domain (PD)
  21         */
  22        RDMA_RESTRACK_PD,
  23        /**
  24         * @RDMA_RESTRACK_CQ: Completion queue (CQ)
  25         */
  26        RDMA_RESTRACK_CQ,
  27        /**
  28         * @RDMA_RESTRACK_QP: Queue pair (QP)
  29         */
  30        RDMA_RESTRACK_QP,
  31        /**
  32         * @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
  33         */
  34        RDMA_RESTRACK_MAX
  35};
  36
  37#define RDMA_RESTRACK_HASH_BITS 8
  38/**
  39 * struct rdma_restrack_root - main resource tracking management
  40 * entity, per-device
  41 */
  42struct rdma_restrack_root {
  43        /*
  44         * @rwsem: Read/write lock to protect lists
  45         */
  46        struct rw_semaphore     rwsem;
  47        /**
  48         * @hash: global database for all resources per-device
  49         */
  50        DECLARE_HASHTABLE(hash, RDMA_RESTRACK_HASH_BITS);
  51};
  52
  53/**
  54 * struct rdma_restrack_entry - metadata per-entry
  55 */
  56struct rdma_restrack_entry {
  57        /**
  58         * @valid: validity indicator
  59         *
  60         * The entries are filled during rdma_restrack_add,
  61         * can be attempted to be free during rdma_restrack_del.
  62         *
  63         * As an example for that, see mlx5 QPs with type MLX5_IB_QPT_HW_GSI
  64         */
  65        bool                    valid;
  66        /*
  67         * @kref: Protect destroy of the resource
  68         */
  69        struct kref             kref;
  70        /*
  71         * @comp: Signal that all consumers of resource are completed their work
  72         */
  73        struct completion       comp;
  74        /**
  75         * @task: owner of resource tracking entity
  76         *
  77         * There are two types of entities: created by user and created
  78         * by kernel.
  79         *
  80         * This is relevant for the entities created by users.
  81         * For the entities created by kernel, this pointer will be NULL.
  82         */
  83        struct task_struct      *task;
  84        /**
  85         * @kern_name: name of owner for the kernel created entities.
  86         */
  87        const char              *kern_name;
  88        /**
  89         * @node: hash table entry
  90         */
  91        struct hlist_node       node;
  92        /**
  93         * @type: various objects in restrack database
  94         */
  95        enum rdma_restrack_type type;
  96};
  97
  98/**
  99 * rdma_restrack_init() - initialize resource tracking
 100 * @res:  resource tracking root
 101 */
 102void rdma_restrack_init(struct rdma_restrack_root *res);
 103
 104/**
 105 * rdma_restrack_clean() - clean resource tracking
 106 * @res:  resource tracking root
 107 */
 108void rdma_restrack_clean(struct rdma_restrack_root *res);
 109
 110/**
 111 * rdma_restrack_count() - the current usage of specific object
 112 * @res:  resource entry
 113 * @type: actual type of object to operate
 114 * @ns:   PID namespace
 115 */
 116int rdma_restrack_count(struct rdma_restrack_root *res,
 117                        enum rdma_restrack_type type,
 118                        struct pid_namespace *ns);
 119
 120/**
 121 * rdma_restrack_add() - add object to the reource tracking database
 122 * @res:  resource entry
 123 */
 124void rdma_restrack_add(struct rdma_restrack_entry *res);
 125
 126/**
 127 * rdma_restrack_del() - delete object from the reource tracking database
 128 * @res:  resource entry
 129 * @type: actual type of object to operate
 130 */
 131void rdma_restrack_del(struct rdma_restrack_entry *res);
 132
 133/**
 134 * rdma_is_kernel_res() - check the owner of resource
 135 * @res:  resource entry
 136 */
 137static inline bool rdma_is_kernel_res(struct rdma_restrack_entry *res)
 138{
 139        return !res->task;
 140}
 141
 142/**
 143 * rdma_restrack_get() - grab to protect resource from release
 144 * @res:  resource entry
 145 */
 146int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
 147
 148/**
 149 * rdma_restrack_put() - relase resource
 150 * @res:  resource entry
 151 */
 152int rdma_restrack_put(struct rdma_restrack_entry *res);
 153#endif /* _RDMA_RESTRACK_H_ */
 154