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  */
23 int 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  */
44 void 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  */
63 int rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type)
64 {
65 	struct rdma_restrack_root *rt = &dev->res[type];
66 	struct rdma_restrack_entry *e;
67 	XA_STATE(xas, &rt->xa, 0);
68 	u32 cnt = 0;
69 
70 	xa_lock(&rt->xa);
71 	xas_for_each(&xas, e, U32_MAX)
72 		cnt++;
73 	xa_unlock(&rt->xa);
74 	return cnt;
75 }
76 EXPORT_SYMBOL(rdma_restrack_count);
77 
78 static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
79 {
80 	switch (res->type) {
81 	case RDMA_RESTRACK_PD:
82 		return container_of(res, struct ib_pd, res)->device;
83 	case RDMA_RESTRACK_CQ:
84 		return container_of(res, struct ib_cq, res)->device;
85 	case RDMA_RESTRACK_QP:
86 		return container_of(res, struct ib_qp, res)->device;
87 	case RDMA_RESTRACK_CM_ID:
88 		return container_of(res, struct rdma_id_private,
89 				    res)->id.device;
90 	case RDMA_RESTRACK_MR:
91 		return container_of(res, struct ib_mr, res)->device;
92 	case RDMA_RESTRACK_CTX:
93 		return container_of(res, struct ib_ucontext, res)->device;
94 	case RDMA_RESTRACK_COUNTER:
95 		return container_of(res, struct rdma_counter, res)->device;
96 	case RDMA_RESTRACK_SRQ:
97 		return container_of(res, struct ib_srq, res)->device;
98 	default:
99 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
100 		return NULL;
101 	}
102 }
103 
104 /**
105  * rdma_restrack_attach_task() - attach the task onto this resource,
106  * valid for user space restrack entries.
107  * @res:  resource entry
108  * @task: the task to attach
109  */
110 static void rdma_restrack_attach_task(struct rdma_restrack_entry *res,
111 				      struct task_struct *task)
112 {
113 	if (WARN_ON_ONCE(!task))
114 		return;
115 
116 	if (res->task)
117 		put_task_struct(res->task);
118 	get_task_struct(task);
119 	res->task = task;
120 	res->user = true;
121 }
122 
123 /**
124  * rdma_restrack_set_name() - set the task for this resource
125  * @res:  resource entry
126  * @caller: kernel name, the current task will be used if the caller is NULL.
127  */
128 void rdma_restrack_set_name(struct rdma_restrack_entry *res, const char *caller)
129 {
130 	if (caller) {
131 		res->kern_name = caller;
132 		return;
133 	}
134 
135 	rdma_restrack_attach_task(res, current);
136 }
137 EXPORT_SYMBOL(rdma_restrack_set_name);
138 
139 /**
140  * rdma_restrack_parent_name() - set the restrack name properties based
141  * on parent restrack
142  * @dst: destination resource entry
143  * @parent: parent resource entry
144  */
145 void rdma_restrack_parent_name(struct rdma_restrack_entry *dst,
146 			       const struct rdma_restrack_entry *parent)
147 {
148 	if (rdma_is_kernel_res(parent))
149 		dst->kern_name = parent->kern_name;
150 	else
151 		rdma_restrack_attach_task(dst, parent->task);
152 }
153 EXPORT_SYMBOL(rdma_restrack_parent_name);
154 
155 /**
156  * rdma_restrack_new() - Initializes new restrack entry to allow _put() interface
157  * to release memory in fully automatic way.
158  * @res: Entry to initialize
159  * @type: REstrack type
160  */
161 void rdma_restrack_new(struct rdma_restrack_entry *res,
162 		       enum rdma_restrack_type type)
163 {
164 	kref_init(&res->kref);
165 	init_completion(&res->comp);
166 	res->type = type;
167 }
168 EXPORT_SYMBOL(rdma_restrack_new);
169 
170 /**
171  * rdma_restrack_add() - add object to the reource tracking database
172  * @res:  resource entry
173  */
174 void rdma_restrack_add(struct rdma_restrack_entry *res)
175 {
176 	struct ib_device *dev = res_to_dev(res);
177 	struct rdma_restrack_root *rt;
178 	int ret = 0;
179 
180 	if (!dev)
181 		return;
182 
183 	if (res->no_track)
184 		goto out;
185 
186 	rt = &dev->res[res->type];
187 
188 	if (res->type == RDMA_RESTRACK_QP) {
189 		/* Special case to ensure that LQPN points to right QP */
190 		struct ib_qp *qp = container_of(res, struct ib_qp, res);
191 
192 		WARN_ONCE(qp->qp_num >> 24 || qp->port >> 8,
193 			  "QP number 0x%0X and port 0x%0X", qp->qp_num,
194 			  qp->port);
195 		res->id = qp->qp_num;
196 		if (qp->qp_type == IB_QPT_SMI || qp->qp_type == IB_QPT_GSI)
197 			res->id |= qp->port << 24;
198 		ret = xa_insert(&rt->xa, res->id, res, GFP_KERNEL);
199 		if (ret)
200 			res->id = 0;
201 	} else if (res->type == RDMA_RESTRACK_COUNTER) {
202 		/* Special case to ensure that cntn points to right counter */
203 		struct rdma_counter *counter;
204 
205 		counter = container_of(res, struct rdma_counter, res);
206 		ret = xa_insert(&rt->xa, counter->id, res, GFP_KERNEL);
207 		res->id = ret ? 0 : counter->id;
208 	} else {
209 		ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
210 				      &rt->next_id, GFP_KERNEL);
211 		ret = (ret < 0) ? ret : 0;
212 	}
213 
214 out:
215 	if (!ret)
216 		res->valid = true;
217 }
218 EXPORT_SYMBOL(rdma_restrack_add);
219 
220 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
221 {
222 	return kref_get_unless_zero(&res->kref);
223 }
224 EXPORT_SYMBOL(rdma_restrack_get);
225 
226 /**
227  * rdma_restrack_get_byid() - translate from ID to restrack object
228  * @dev: IB device
229  * @type: resource track type
230  * @id: ID to take a look
231  *
232  * Return: Pointer to restrack entry or -ENOENT in case of error.
233  */
234 struct rdma_restrack_entry *
235 rdma_restrack_get_byid(struct ib_device *dev,
236 		       enum rdma_restrack_type type, u32 id)
237 {
238 	struct rdma_restrack_root *rt = &dev->res[type];
239 	struct rdma_restrack_entry *res;
240 
241 	xa_lock(&rt->xa);
242 	res = xa_load(&rt->xa, id);
243 	if (!res || !rdma_restrack_get(res))
244 		res = ERR_PTR(-ENOENT);
245 	xa_unlock(&rt->xa);
246 
247 	return res;
248 }
249 EXPORT_SYMBOL(rdma_restrack_get_byid);
250 
251 static void restrack_release(struct kref *kref)
252 {
253 	struct rdma_restrack_entry *res;
254 
255 	res = container_of(kref, struct rdma_restrack_entry, kref);
256 	if (res->task) {
257 		put_task_struct(res->task);
258 		res->task = NULL;
259 	}
260 	complete(&res->comp);
261 }
262 
263 int rdma_restrack_put(struct rdma_restrack_entry *res)
264 {
265 	return kref_put(&res->kref, restrack_release);
266 }
267 EXPORT_SYMBOL(rdma_restrack_put);
268 
269 /**
270  * rdma_restrack_del() - delete object from the reource tracking database
271  * @res:  resource entry
272  */
273 void rdma_restrack_del(struct rdma_restrack_entry *res)
274 {
275 	struct rdma_restrack_entry *old;
276 	struct rdma_restrack_root *rt;
277 	struct ib_device *dev;
278 
279 	if (!res->valid) {
280 		if (res->task) {
281 			put_task_struct(res->task);
282 			res->task = NULL;
283 		}
284 		return;
285 	}
286 
287 	if (res->no_track)
288 		goto out;
289 
290 	dev = res_to_dev(res);
291 	if (WARN_ON(!dev))
292 		return;
293 
294 	rt = &dev->res[res->type];
295 
296 	old = xa_erase(&rt->xa, res->id);
297 	WARN_ON(old != res);
298 
299 out:
300 	res->valid = false;
301 	rdma_restrack_put(res);
302 	wait_for_completion(&res->comp);
303 }
304 EXPORT_SYMBOL(rdma_restrack_del);
305