include/rdma/restrack.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
   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 #include <linux/sched/task.h>
  15 #include <uapi/rdma/rdma_netlink.h>
  16
  17 /**
  18  * enum rdma_restrack_type - HW objects to track
  19  */
  20 enum rdma_restrack_type {
  21         /**
  22          * @RDMA_RESTRACK_PD: Protection domain (PD)
  23          */
  24         RDMA_RESTRACK_PD,
  25         /**
  26          * @RDMA_RESTRACK_CQ: Completion queue (CQ)
  27          */
  28         RDMA_RESTRACK_CQ,
  29         /**
  30          * @RDMA_RESTRACK_QP: Queue pair (QP)
  31          */
  32         RDMA_RESTRACK_QP,
  33         /**
  34          * @RDMA_RESTRACK_CM_ID: Connection Manager ID (CM_ID)
  35          */
  36         RDMA_RESTRACK_CM_ID,
  37         /**
  38          * @RDMA_RESTRACK_MR: Memory Region (MR)
  39          */
  40         RDMA_RESTRACK_MR,
  41         /**
  42          * @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
  43          */
  44         RDMA_RESTRACK_MAX
  45 };
  46
  47 #define RDMA_RESTRACK_HASH_BITS 8
  48 struct rdma_restrack_entry;
  49
  50 /**
  51  * struct rdma_restrack_root - main resource tracking management
  52  * entity, per-device
  53  */
  54 struct rdma_restrack_root {
  55         /*
  56          * @rwsem: Read/write lock to protect lists
  57          */
  58         struct rw_semaphore     rwsem;
  59         /**
  60          * @hash: global database for all resources per-device
  61          */
  62         DECLARE_HASHTABLE(hash, RDMA_RESTRACK_HASH_BITS);
  63         /**
  64          * @fill_res_entry: driver-specific fill function
  65          *
  66          * Allows rdma drivers to add their own restrack attributes.
  67          */
  68         int (*fill_res_entry)(struct sk_buff *msg,
  69                               struct rdma_restrack_entry *entry);
  70 };
  71
  72 /**
  73  * struct rdma_restrack_entry - metadata per-entry
  74  */
  75 struct rdma_restrack_entry {
  76         /**
  77          * @valid: validity indicator
  78          *
  79          * The entries are filled during rdma_restrack_add,
  80          * can be attempted to be free during rdma_restrack_del.
  81          *
  82          * As an example for that, see mlx5 QPs with type MLX5_IB_QPT_HW_GSI
  83          */
  84         bool                    valid;
  85         /*
  86          * @kref: Protect destroy of the resource
  87          */
  88         struct kref             kref;
  89         /*
  90          * @comp: Signal that all consumers of resource are completed their work
  91          */
  92         struct completion       comp;
  93         /**
  94          * @task: owner of resource tracking entity
  95          *
  96          * There are two types of entities: created by user and created
  97          * by kernel.
  98          *
  99          * This is relevant for the entities created by users.
 100          * For the entities created by kernel, this pointer will be NULL.
 101          */
 102         struct task_struct      *task;
 103         /**
 104          * @kern_name: name of owner for the kernel created entities.
 105          */
 106         const char              *kern_name;
 107         /**
 108          * @node: hash table entry
 109          */
 110         struct hlist_node       node;
 111         /**
 112          * @type: various objects in restrack database
 113          */
 114         enum rdma_restrack_type type;
 115 };
 116
 117 /**
 118  * rdma_restrack_init() - initialize resource tracking
 119  * @res:  resource tracking root
 120  */
 121 void rdma_restrack_init(struct rdma_restrack_root *res);
 122
 123 /**
 124  * rdma_restrack_clean() - clean resource tracking
 125  * @res:  resource tracking root
 126  */
 127 void rdma_restrack_clean(struct rdma_restrack_root *res);
 128
 129 /**
 130  * rdma_restrack_count() - the current usage of specific object
 131  * @res:  resource entry
 132  * @type: actual type of object to operate
 133  * @ns:   PID namespace
 134  */
 135 int rdma_restrack_count(struct rdma_restrack_root *res,
 136                         enum rdma_restrack_type type,
 137                         struct pid_namespace *ns);
 138
 139 /**
 140  * rdma_restrack_add() - add object to the reource tracking database
 141  * @res:  resource entry
 142  */
 143 void rdma_restrack_add(struct rdma_restrack_entry *res);
 144
 145 /**
 146  * rdma_restrack_del() - delete object from the reource tracking database
 147  * @res:  resource entry
 148  * @type: actual type of object to operate
 149  */
 150 void rdma_restrack_del(struct rdma_restrack_entry *res);
 151
 152 /**
 153  * rdma_is_kernel_res() - check the owner of resource
 154  * @res:  resource entry
 155  */
 156 static inline bool rdma_is_kernel_res(struct rdma_restrack_entry *res)
 157 {
 158         return !res->task;
 159 }
 160
 161 /**
 162  * rdma_restrack_get() - grab to protect resource from release
 163  * @res:  resource entry
 164  */
 165 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
 166
 167 /**
 168  * rdma_restrack_put() - release resource
 169  * @res:  resource entry
 170  */
 171 int rdma_restrack_put(struct rdma_restrack_entry *res);
 172
 173 /**
 174  * rdma_restrack_set_task() - set the task for this resource
 175  * @res:  resource entry
 176  * @task: task struct
 177  */
 178 static inline void rdma_restrack_set_task(struct rdma_restrack_entry *res,
 179                                           struct task_struct *task)
 180 {
 181         if (res->task)
 182                 put_task_struct(res->task);
 183         get_task_struct(task);
 184         res->task = task;
 185 }
 186
 187 /*
 188  * Helper functions for rdma drivers when filling out
 189  * nldev driver attributes.
 190  */
 191 int rdma_nl_put_driver_u32(struct sk_buff *msg, const char *name, u32 value);
 192 int rdma_nl_put_driver_u32_hex(struct sk_buff *msg, const char *name,
 193                                u32 value);
 194 int rdma_nl_put_driver_u64(struct sk_buff *msg, const char *name, u64 value);
 195 int rdma_nl_put_driver_u64_hex(struct sk_buff *msg, const char *name,
 196                                u64 value);
 197 #endif /* _RDMA_RESTRACK_H_ */