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  */
  18 enum 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  */
  42 struct 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  */
  56 struct 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  */
 102 void rdma_restrack_init(struct rdma_restrack_root *res);
 103
 104 /**
 105  * rdma_restrack_clean() - clean resource tracking
 106  * @res:  resource tracking root
 107  */
 108 void 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  */
 116 int 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  */
 124 void 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  */
 131 void 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  */
 137 static 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  */
 146 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
 147
 148 /**
 149  * rdma_restrack_put() - relase resource
 150  * @res:  resource entry
 151  */
 152 int rdma_restrack_put(struct rdma_restrack_entry *res);
 153 #endif /* _RDMA_RESTRACK_H_ */