xref: /linux/drivers/infiniband/core/restrack.c (revision 36ec807b627b4c0a0a382f0ae48eac7187d14b2b)
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  * @show_details: count driver specific objects
63  */
64 int 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 }
81 EXPORT_SYMBOL(rdma_restrack_count);
82 
83 static 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  */
115 static 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  */
133 void 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 }
142 EXPORT_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  */
150 void 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 }
158 EXPORT_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  */
166 void 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 }
173 EXPORT_SYMBOL(rdma_restrack_new);
174 
175 /**
176  * rdma_restrack_add() - add object to the reource tracking database
177  * @res:  resource entry
178  */
179 void 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 
222 out:
223 	if (!ret)
224 		res->valid = true;
225 }
226 EXPORT_SYMBOL(rdma_restrack_add);
227 
228 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
229 {
230 	return kref_get_unless_zero(&res->kref);
231 }
232 EXPORT_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  */
242 struct rdma_restrack_entry *
243 rdma_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 }
257 EXPORT_SYMBOL(rdma_restrack_get_byid);
258 
259 static 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 
271 int rdma_restrack_put(struct rdma_restrack_entry *res)
272 {
273 	return kref_put(&res->kref, restrack_release);
274 }
275 EXPORT_SYMBOL(rdma_restrack_put);
276 
277 /**
278  * rdma_restrack_del() - delete object from the reource tracking database
279  * @res:  resource entry
280  */
281 void 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 
307 out:
308 	res->valid = false;
309 	rdma_restrack_put(res);
310 	wait_for_completion(&res->comp);
311 }
312 EXPORT_SYMBOL(rdma_restrack_del);
313