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_XRCD: XRC domain (XRCD)
  33          */
  34         RDMA_RESTRACK_XRCD,
  35         /**
  36          * @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
  37          */
  38         RDMA_RESTRACK_MAX
  39 };
  40
  41 #define RDMA_RESTRACK_HASH_BITS 8
  42 /**
  43  * struct rdma_restrack_root - main resource tracking management
  44  * entity, per-device
  45  */
  46 struct rdma_restrack_root {
  47         /*
  48          * @rwsem: Read/write lock to protect lists
  49          */
  50         struct rw_semaphore     rwsem;
  51         /**
  52          * @hash: global database for all resources per-device
  53          */
  54         DECLARE_HASHTABLE(hash, RDMA_RESTRACK_HASH_BITS);
  55 };
  56
  57 /**
  58  * struct rdma_restrack_entry - metadata per-entry
  59  */
  60 struct rdma_restrack_entry {
  61         /**
  62          * @valid: validity indicator
  63          *
  64          * The entries are filled during rdma_restrack_add,
  65          * can be attempted to be free during rdma_restrack_del.
  66          *
  67          * As an example for that, see mlx5 QPs with type MLX5_IB_QPT_HW_GSI
  68          */
  69         bool                    valid;
  70         /*
  71          * @kref: Protect destroy of the resource
  72          */
  73         struct kref             kref;
  74         /*
  75          * @comp: Signal that all consumers of resource are completed their work
  76          */
  77         struct completion       comp;
  78         /**
  79          * @task: owner of resource tracking entity
  80          *
  81          * There are two types of entities: created by user and created
  82          * by kernel.
  83          *
  84          * This is relevant for the entities created by users.
  85          * For the entities created by kernel, this pointer will be NULL.
  86          */
  87         struct task_struct      *task;
  88         /**
  89          * @kern_name: name of owner for the kernel created entities.
  90          */
  91         const char              *kern_name;
  92         /**
  93          * @node: hash table entry
  94          */
  95         struct hlist_node       node;
  96         /**
  97          * @type: various objects in restrack database
  98          */
  99         enum rdma_restrack_type type;
 100 };
 101
 102 /**
 103  * rdma_restrack_init() - initialize resource tracking
 104  * @res:  resource tracking root
 105  */
 106 void rdma_restrack_init(struct rdma_restrack_root *res);
 107
 108 /**
 109  * rdma_restrack_clean() - clean resource tracking
 110  * @res:  resource tracking root
 111  */
 112 void rdma_restrack_clean(struct rdma_restrack_root *res);
 113
 114 /**
 115  * rdma_restrack_count() - the current usage of specific object
 116  * @res:  resource entry
 117  * @type: actual type of object to operate
 118  * @ns:   PID namespace
 119  */
 120 int rdma_restrack_count(struct rdma_restrack_root *res,
 121                         enum rdma_restrack_type type,
 122                         struct pid_namespace *ns);
 123
 124 /**
 125  * rdma_restrack_add() - add object to the reource tracking database
 126  * @res:  resource entry
 127  */
 128 void rdma_restrack_add(struct rdma_restrack_entry *res);
 129
 130 /**
 131  * rdma_restrack_del() - delete object from the reource tracking database
 132  * @res:  resource entry
 133  * @type: actual type of object to operate
 134  */
 135 void rdma_restrack_del(struct rdma_restrack_entry *res);
 136
 137 /**
 138  * rdma_is_kernel_res() - check the owner of resource
 139  * @res:  resource entry
 140  */
 141 static inline bool rdma_is_kernel_res(struct rdma_restrack_entry *res)
 142 {
 143         return !res->task;
 144 }
 145
 146 /**
 147  * rdma_restrack_get() - grab to protect resource from release
 148  * @res:  resource entry
 149  */
 150 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
 151
 152 /**
 153  * rdma_restrack_put() - relase resource
 154  * @res:  resource entry
 155  */
 156 int rdma_restrack_put(struct rdma_restrack_entry *res);
 157 #endif /* _RDMA_RESTRACK_H_ */