linux/include/rdma/restrack.h

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/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
/*
* Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
*/
#ifndef _RDMA_RESTRACK_H_
#define _RDMA_RESTRACK_H_
#include <linux/typecheck.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/kref.h>
#include <linux/completion.h>
#include <linux/sched/task.h>
/**
* enum rdma_restrack_type - HW objects to track
*/
enum rdma_restrack_type {
/**
* @RDMA_RESTRACK_PD: Protection domain (PD)
*/
RDMA_RESTRACK_PD,
/**
* @RDMA_RESTRACK_CQ: Completion queue (CQ)
*/
RDMA_RESTRACK_CQ,
/**
* @RDMA_RESTRACK_QP: Queue pair (QP)
*/
RDMA_RESTRACK_QP,
/**
* @RDMA_RESTRACK_CM_ID: Connection Manager ID (CM_ID)
*/
RDMA_RESTRACK_CM_ID,
/**
* @RDMA_RESTRACK_MR: Memory Region (MR)
*/
RDMA_RESTRACK_MR,
/**
* @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
*/
RDMA_RESTRACK_MAX
};
#define RDMA_RESTRACK_HASH_BITS 8
/**
* struct rdma_restrack_root - main resource tracking management
* entity, per-device
*/
struct rdma_restrack_root {
/*
* @rwsem: Read/write lock to protect lists
*/
struct rw_semaphore rwsem;
/**
* @hash: global database for all resources per-device
*/
DECLARE_HASHTABLE(hash, RDMA_RESTRACK_HASH_BITS);
};
/**
* struct rdma_restrack_entry - metadata per-entry
*/
struct rdma_restrack_entry {
/**
* @valid: validity indicator
*
* The entries are filled during rdma_restrack_add,
* can be attempted to be free during rdma_restrack_del.
*
* As an example for that, see mlx5 QPs with type MLX5_IB_QPT_HW_GSI
*/
bool valid;
/*
* @kref: Protect destroy of the resource
*/
struct kref kref;
/*
* @comp: Signal that all consumers of resource are completed their work
*/
struct completion comp;
/**
* @task: owner of resource tracking entity
*
* There are two types of entities: created by user and created
* by kernel.
*
* This is relevant for the entities created by users.
* For the entities created by kernel, this pointer will be NULL.
*/
struct task_struct *task;
/**
* @kern_name: name of owner for the kernel created entities.
*/
const char *kern_name;
/**
* @node: hash table entry
*/
struct hlist_node node;
/**
* @type: various objects in restrack database
*/
enum rdma_restrack_type type;
};
/**
* rdma_restrack_init() - initialize resource tracking
* @res: resource tracking root
*/
void rdma_restrack_init(struct rdma_restrack_root *res);
/**
* rdma_restrack_clean() - clean resource tracking
* @res: resource tracking root
*/
void rdma_restrack_clean(struct rdma_restrack_root *res);
/**
* rdma_restrack_count() - the current usage of specific object
* @res: resource entry
* @type: actual type of object to operate
* @ns: PID namespace
*/
int rdma_restrack_count(struct rdma_restrack_root *res,
enum rdma_restrack_type type,
struct pid_namespace *ns);
/**
* rdma_restrack_add() - add object to the reource tracking database
* @res: resource entry
*/
void rdma_restrack_add(struct rdma_restrack_entry *res);
/**
* rdma_restrack_del() - delete object from the reource tracking database
* @res: resource entry
* @type: actual type of object to operate
*/
void rdma_restrack_del(struct rdma_restrack_entry *res);
/**
* rdma_is_kernel_res() - check the owner of resource
* @res: resource entry
*/
static inline bool rdma_is_kernel_res(struct rdma_restrack_entry *res)
{
return !res->task;
}
/**
* rdma_restrack_get() - grab to protect resource from release
* @res: resource entry
*/
int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
/**
* rdma_restrack_put() - relase resource
* @res: resource entry
*/
int rdma_restrack_put(struct rdma_restrack_entry *res);
/**
* rdma_restrack_set_task() - set the task for this resource
* @res: resource entry
* @task: task struct
*/
static inline void rdma_restrack_set_task(struct rdma_restrack_entry *res,
struct task_struct *task)
{
if (res->task)
put_task_struct(res->task);
get_task_struct(task);
res->task = task;
}
#endif /* _RDMA_RESTRACK_H_ */