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