drivers/infiniband/core/restrack.c

   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);