1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
  2/*
  3 * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
  4 */
  5
  6#include <rdma/rdma_cm.h>
  7#include <rdma/ib_verbs.h>
  8#include <rdma/restrack.h>
  9#include <rdma/rdma_counter.h>
 10#include <linux/mutex.h>
 11#include <linux/sched/task.h>
 12#include <linux/pid_namespace.h>
 13
 14#include "cma_priv.h"
 15#include "restrack.h"
 16
 17/**
 18 * rdma_restrack_init() - initialize and allocate resource tracking
 19 * @dev:  IB device
 20 *
 21 * Return: 0 on success
 22 */
 23int rdma_restrack_init(struct ib_device *dev)
 24{
 25	struct rdma_restrack_root *rt;
 26	int i;
 27
 28	dev->res = kcalloc(RDMA_RESTRACK_MAX, sizeof(*rt), GFP_KERNEL);
 29	if (!dev->res)
 30		return -ENOMEM;
 31
 32	rt = dev->res;
 33
 34	for (i = 0; i < RDMA_RESTRACK_MAX; i++)
 35		xa_init_flags(&rt[i].xa, XA_FLAGS_ALLOC);
 36
 37	return 0;
 38}
 39
 40/**
 41 * rdma_restrack_clean() - clean resource tracking
 42 * @dev:  IB device
 43 */
 44void rdma_restrack_clean(struct ib_device *dev)
 45{
 46	struct rdma_restrack_root *rt = dev->res;
 47	int i;
 48
 49	for (i = 0 ; i < RDMA_RESTRACK_MAX; i++) {
 50		struct xarray *xa = &dev->res[i].xa;
 51
 52		WARN_ON(!xa_empty(xa));
 53		xa_destroy(xa);
 54	}
 55	kfree(rt);
 56}
 57
 58/**
 59 * rdma_restrack_count() - the current usage of specific object
 60 * @dev:  IB device
 61 * @type: actual type of object to operate
 62 * @show_details: count driver specific objects
 63 */
 64int rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type,
 65			bool show_details)
 66{
 67	struct rdma_restrack_root *rt = &dev->res[type];
 68	struct rdma_restrack_entry *e;
 69	XA_STATE(xas, &rt->xa, 0);
 70	u32 cnt = 0;
 71
 72	xa_lock(&rt->xa);
 73	xas_for_each(&xas, e, U32_MAX) {
 74		if (xa_get_mark(&rt->xa, e->id, RESTRACK_DD) && !show_details)
 75			continue;
 76		cnt++;
 77	}
 78	xa_unlock(&rt->xa);
 79	return cnt;
 80}
 81EXPORT_SYMBOL(rdma_restrack_count);
 82
 83static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
 84{
 85	switch (res->type) {
 86	case RDMA_RESTRACK_PD:
 87		return container_of(res, struct ib_pd, res)->device;
 88	case RDMA_RESTRACK_CQ:
 89		return container_of(res, struct ib_cq, res)->device;
 90	case RDMA_RESTRACK_QP:
 91		return container_of(res, struct ib_qp, res)->device;
 92	case RDMA_RESTRACK_CM_ID:
 93		return container_of(res, struct rdma_id_private,
 94				    res)->id.device;
 95	case RDMA_RESTRACK_MR:
 96		return container_of(res, struct ib_mr, res)->device;
 97	case RDMA_RESTRACK_CTX:
 98		return container_of(res, struct ib_ucontext, res)->device;
 99	case RDMA_RESTRACK_COUNTER:
100		return container_of(res, struct rdma_counter, res)->device;
101	case RDMA_RESTRACK_SRQ:
102		return container_of(res, struct ib_srq, res)->device;
103	default:
104		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
105		return NULL;
106	}
107}
108
109/**
110 * rdma_restrack_attach_task() - attach the task onto this resource,
111 * valid for user space restrack entries.
112 * @res:  resource entry
113 * @task: the task to attach
114 */
115static void rdma_restrack_attach_task(struct rdma_restrack_entry *res,
116				      struct task_struct *task)
117{
118	if (WARN_ON_ONCE(!task))
119		return;
120
121	if (res->task)
122		put_task_struct(res->task);
123	get_task_struct(task);
124	res->task = task;
125	res->user = true;
126}
127
128/**
129 * rdma_restrack_set_name() - set the task for this resource
130 * @res:  resource entry
131 * @caller: kernel name, the current task will be used if the caller is NULL.
132 */
133void rdma_restrack_set_name(struct rdma_restrack_entry *res, const char *caller)
134{
135	if (caller) {
136		res->kern_name = caller;
137		return;
138	}
139
140	rdma_restrack_attach_task(res, current);
141}
142EXPORT_SYMBOL(rdma_restrack_set_name);
143
144/**
145 * rdma_restrack_parent_name() - set the restrack name properties based
146 * on parent restrack
147 * @dst: destination resource entry
148 * @parent: parent resource entry
149 */
150void rdma_restrack_parent_name(struct rdma_restrack_entry *dst,
151			       const struct rdma_restrack_entry *parent)
152{
153	if (rdma_is_kernel_res(parent))
154		dst->kern_name = parent->kern_name;
155	else
156		rdma_restrack_attach_task(dst, parent->task);
157}
158EXPORT_SYMBOL(rdma_restrack_parent_name);
159
160/**
161 * rdma_restrack_new() - Initializes new restrack entry to allow _put() interface
162 * to release memory in fully automatic way.
163 * @res: Entry to initialize
164 * @type: REstrack type
165 */
166void rdma_restrack_new(struct rdma_restrack_entry *res,
167		       enum rdma_restrack_type type)
168{
169	kref_init(&res->kref);
170	init_completion(&res->comp);
171	res->type = type;
172}
173EXPORT_SYMBOL(rdma_restrack_new);
174
175/**
176 * rdma_restrack_add() - add object to the reource tracking database
177 * @res:  resource entry
178 */
179void rdma_restrack_add(struct rdma_restrack_entry *res)
180{
181	struct ib_device *dev = res_to_dev(res);
182	struct rdma_restrack_root *rt;
183	int ret = 0;
184
185	if (!dev)
186		return;
187
188	if (res->no_track)
189		goto out;
190
191	rt = &dev->res[res->type];
192
193	if (res->type == RDMA_RESTRACK_QP) {
194		/* Special case to ensure that LQPN points to right QP */
195		struct ib_qp *qp = container_of(res, struct ib_qp, res);
196
197		WARN_ONCE(qp->qp_num >> 24 || qp->port >> 8,
198			  "QP number 0x%0X and port 0x%0X", qp->qp_num,
199			  qp->port);
200		res->id = qp->qp_num;
201		if (qp->qp_type == IB_QPT_SMI || qp->qp_type == IB_QPT_GSI)
202			res->id |= qp->port << 24;
203		ret = xa_insert(&rt->xa, res->id, res, GFP_KERNEL);
204		if (ret)
205			res->id = 0;
206
207		if (qp->qp_type >= IB_QPT_DRIVER)
208			xa_set_mark(&rt->xa, res->id, RESTRACK_DD);
209	} else if (res->type == RDMA_RESTRACK_COUNTER) {
210		/* Special case to ensure that cntn points to right counter */
211		struct rdma_counter *counter;
212
213		counter = container_of(res, struct rdma_counter, res);
214		ret = xa_insert(&rt->xa, counter->id, res, GFP_KERNEL);
215		res->id = ret ? 0 : counter->id;
216	} else {
217		ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
218				      &rt->next_id, GFP_KERNEL);
219		ret = (ret < 0) ? ret : 0;
220	}
221
222out:
223	if (!ret)
224		res->valid = true;
225}
226EXPORT_SYMBOL(rdma_restrack_add);
227
228int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
229{
230	return kref_get_unless_zero(&res->kref);
231}
232EXPORT_SYMBOL(rdma_restrack_get);
233
234/**
235 * rdma_restrack_get_byid() - translate from ID to restrack object
236 * @dev: IB device
237 * @type: resource track type
238 * @id: ID to take a look
239 *
240 * Return: Pointer to restrack entry or -ENOENT in case of error.
241 */
242struct rdma_restrack_entry *
243rdma_restrack_get_byid(struct ib_device *dev,
244		       enum rdma_restrack_type type, u32 id)
245{
246	struct rdma_restrack_root *rt = &dev->res[type];
247	struct rdma_restrack_entry *res;
248
249	xa_lock(&rt->xa);
250	res = xa_load(&rt->xa, id);
251	if (!res || !rdma_restrack_get(res))
252		res = ERR_PTR(-ENOENT);
253	xa_unlock(&rt->xa);
254
255	return res;
256}
257EXPORT_SYMBOL(rdma_restrack_get_byid);
258
259static void restrack_release(struct kref *kref)
260{
261	struct rdma_restrack_entry *res;
262
263	res = container_of(kref, struct rdma_restrack_entry, kref);
264	if (res->task) {
265		put_task_struct(res->task);
266		res->task = NULL;
267	}
268	complete(&res->comp);
269}
270
271int rdma_restrack_put(struct rdma_restrack_entry *res)
272{
273	return kref_put(&res->kref, restrack_release);
274}
275EXPORT_SYMBOL(rdma_restrack_put);
276
277/**
278 * rdma_restrack_del() - delete object from the reource tracking database
279 * @res:  resource entry
280 */
281void rdma_restrack_del(struct rdma_restrack_entry *res)
282{
283	struct rdma_restrack_entry *old;
284	struct rdma_restrack_root *rt;
285	struct ib_device *dev;
286
287	if (!res->valid) {
288		if (res->task) {
289			put_task_struct(res->task);
290			res->task = NULL;
291		}
292		return;
293	}
294
295	if (res->no_track)
296		goto out;
297
298	dev = res_to_dev(res);
299	if (WARN_ON(!dev))
300		return;
301
302	rt = &dev->res[res->type];
303
304	old = xa_erase(&rt->xa, res->id);
305	WARN_ON(old != res);
306
307out:
308	res->valid = false;
309	rdma_restrack_put(res);
310	wait_for_completion(&res->comp);
311}
312EXPORT_SYMBOL(rdma_restrack_del);