drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c

   1 // SPDX-License-Identifier: ISC
   2 /*
   3  * Copyright (c) 2016 Broadcom
   4  */
   5 #include <linux/netdevice.h>
   6 #include <linux/gcd.h>
   7 #include <net/cfg80211.h>
   8
   9 #include "core.h"
  10 #include "debug.h"
  11 #include "fwil.h"
  12 #include "fwil_types.h"
  13 #include "cfg80211.h"
  14 #include "pno.h"
  15
  16 #define BRCMF_PNO_VERSION               2
  17 #define BRCMF_PNO_REPEAT                4
  18 #define BRCMF_PNO_FREQ_EXPO_MAX         3
  19 #define BRCMF_PNO_IMMEDIATE_SCAN_BIT    3
  20 #define BRCMF_PNO_ENABLE_BD_SCAN_BIT    5
  21 #define BRCMF_PNO_ENABLE_ADAPTSCAN_BIT  6
  22 #define BRCMF_PNO_REPORT_SEPARATELY_BIT 11
  23 #define BRCMF_PNO_SCAN_INCOMPLETE       0
  24 #define BRCMF_PNO_WPA_AUTH_ANY          0xFFFFFFFF
  25 #define BRCMF_PNO_HIDDEN_BIT            2
  26 #define BRCMF_PNO_SCHED_SCAN_PERIOD     30
  27
  28 #define BRCMF_PNO_MAX_BUCKETS           16
  29 #define GSCAN_BATCH_NO_THR_SET                  101
  30 #define GSCAN_RETRY_THRESHOLD                   3
  31
  32 struct brcmf_pno_info {
  33         int n_reqs;
  34         struct cfg80211_sched_scan_request *reqs[BRCMF_PNO_MAX_BUCKETS];
  35         struct mutex req_lock;
  36 };
  37
  38 #define ifp_to_pno(_ifp)        ((_ifp)->drvr->config->pno)
  39
  40 static int brcmf_pno_store_request(struct brcmf_pno_info *pi,
  41                                    struct cfg80211_sched_scan_request *req)
  42 {
  43         if (WARN(pi->n_reqs == BRCMF_PNO_MAX_BUCKETS,
  44                  "pno request storage full\n"))
  45                 return -ENOSPC;
  46
  47         brcmf_dbg(SCAN, "reqid=%llu\n", req->reqid);
  48         mutex_lock(&pi->req_lock);
  49         pi->reqs[pi->n_reqs++] = req;
  50         mutex_unlock(&pi->req_lock);
  51         return 0;
  52 }
  53
  54 static int brcmf_pno_remove_request(struct brcmf_pno_info *pi, u64 reqid)
  55 {
  56         int i, err = 0;
  57
  58         mutex_lock(&pi->req_lock);
  59
  60         /* Nothing to do if we have no requests */
  61         if (pi->n_reqs == 0)
  62                 goto done;
  63
  64         /* find request */
  65         for (i = 0; i < pi->n_reqs; i++) {
  66                 if (pi->reqs[i]->reqid == reqid)
  67                         break;
  68         }
  69         /* request not found */
  70         if (WARN(i == pi->n_reqs, "reqid not found\n")) {
  71                 err = -ENOENT;
  72                 goto done;
  73         }
  74
  75         brcmf_dbg(SCAN, "reqid=%llu\n", reqid);
  76         pi->n_reqs--;
  77
  78         /* if last we are done */
  79         if (!pi->n_reqs || i == pi->n_reqs)
  80                 goto done;
  81
  82         /* fill the gap with remaining requests */
  83         while (i <= pi->n_reqs - 1) {
  84                 pi->reqs[i] = pi->reqs[i + 1];
  85                 i++;
  86         }
  87
  88 done:
  89         mutex_unlock(&pi->req_lock);
  90         return err;
  91 }
  92
  93 static int brcmf_pno_channel_config(struct brcmf_if *ifp,
  94                                     struct brcmf_pno_config_le *cfg)
  95 {
  96         cfg->reporttype = 0;
  97         cfg->flags = 0;
  98
  99         return brcmf_fil_iovar_data_set(ifp, "pfn_cfg", cfg, sizeof(*cfg));
 100 }
 101
 102 static int brcmf_pno_config(struct brcmf_if *ifp, u32 scan_freq,
 103                             u32 mscan, u32 bestn)
 104 {
 105         struct brcmf_pub *drvr = ifp->drvr;
 106         struct brcmf_pno_param_le pfn_param;
 107         u16 flags;
 108         u32 pfnmem;
 109         s32 err;
 110
 111         memset(&pfn_param, 0, sizeof(pfn_param));
 112         pfn_param.version = cpu_to_le32(BRCMF_PNO_VERSION);
 113
 114         /* set extra pno params */
 115         flags = BIT(BRCMF_PNO_IMMEDIATE_SCAN_BIT) |
 116                 BIT(BRCMF_PNO_ENABLE_ADAPTSCAN_BIT);
 117         pfn_param.repeat = BRCMF_PNO_REPEAT;
 118         pfn_param.exp = BRCMF_PNO_FREQ_EXPO_MAX;
 119
 120         /* set up pno scan fr */
 121         pfn_param.scan_freq = cpu_to_le32(scan_freq);
 122
 123         if (mscan) {
 124                 pfnmem = bestn;
 125
 126                 /* set bestn in firmware */
 127                 err = brcmf_fil_iovar_int_set(ifp, "pfnmem", pfnmem);
 128                 if (err < 0) {
 129                         bphy_err(drvr, "failed to set pfnmem\n");
 130                         goto exit;
 131                 }
 132                 /* get max mscan which the firmware supports */
 133                 err = brcmf_fil_iovar_int_get(ifp, "pfnmem", &pfnmem);
 134                 if (err < 0) {
 135                         bphy_err(drvr, "failed to get pfnmem\n");
 136                         goto exit;
 137                 }
 138                 mscan = min_t(u32, mscan, pfnmem);
 139                 pfn_param.mscan = mscan;
 140                 pfn_param.bestn = bestn;
 141                 flags |= BIT(BRCMF_PNO_ENABLE_BD_SCAN_BIT);
 142                 brcmf_dbg(INFO, "mscan=%d, bestn=%d\n", mscan, bestn);
 143         }
 144
 145         pfn_param.flags = cpu_to_le16(flags);
 146         err = brcmf_fil_iovar_data_set(ifp, "pfn_set", &pfn_param,
 147                                        sizeof(pfn_param));
 148         if (err)
 149                 bphy_err(drvr, "pfn_set failed, err=%d\n", err);
 150
 151 exit:
 152         return err;
 153 }
 154
 155 static int brcmf_pno_set_random(struct brcmf_if *ifp, struct brcmf_pno_info *pi)
 156 {
 157         struct brcmf_pub *drvr = ifp->drvr;
 158         struct brcmf_pno_macaddr_le pfn_mac;
 159         u8 *mac_addr = NULL;
 160         u8 *mac_mask = NULL;
 161         int err, i, ri;
 162
 163         for (ri = 0; ri < pi->n_reqs; ri++)
 164                 if (pi->reqs[ri]->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {
 165                         mac_addr = pi->reqs[ri]->mac_addr;
 166                         mac_mask = pi->reqs[ri]->mac_addr_mask;
 167                         break;
 168                 }
 169
 170         /* no random mac requested */
 171         if (!mac_addr)
 172                 return 0;
 173
 174         pfn_mac.version = BRCMF_PFN_MACADDR_CFG_VER;
 175         pfn_mac.flags = BRCMF_PFN_MAC_OUI_ONLY | BRCMF_PFN_SET_MAC_UNASSOC;
 176
 177         memcpy(pfn_mac.mac, mac_addr, ETH_ALEN);
 178         for (i = 0; i < ETH_ALEN; i++) {
 179                 pfn_mac.mac[i] &= mac_mask[i];
 180                 pfn_mac.mac[i] |= get_random_int() & ~(mac_mask[i]);
 181         }
 182         /* Clear multi bit */
 183         pfn_mac.mac[0] &= 0xFE;
 184         /* Set locally administered */
 185         pfn_mac.mac[0] |= 0x02;
 186
 187         brcmf_dbg(SCAN, "enabling random mac: reqid=%llu mac=%pM\n",
 188                   pi->reqs[ri]->reqid, pfn_mac.mac);
 189         err = brcmf_fil_iovar_data_set(ifp, "pfn_macaddr", &pfn_mac,
 190                                        sizeof(pfn_mac));
 191         if (err)
 192                 bphy_err(drvr, "pfn_macaddr failed, err=%d\n", err);
 193
 194         return err;
 195 }
 196
 197 static int brcmf_pno_add_ssid(struct brcmf_if *ifp, struct cfg80211_ssid *ssid,
 198                               bool active)
 199 {
 200         struct brcmf_pub *drvr = ifp->drvr;
 201         struct brcmf_pno_net_param_le pfn;
 202         int err;
 203
 204         pfn.auth = cpu_to_le32(WLAN_AUTH_OPEN);
 205         pfn.wpa_auth = cpu_to_le32(BRCMF_PNO_WPA_AUTH_ANY);
 206         pfn.wsec = cpu_to_le32(0);
 207         pfn.infra = cpu_to_le32(1);
 208         pfn.flags = 0;
 209         if (active)
 210                 pfn.flags = cpu_to_le32(1 << BRCMF_PNO_HIDDEN_BIT);
 211         pfn.ssid.SSID_len = cpu_to_le32(ssid->ssid_len);
 212         memcpy(pfn.ssid.SSID, ssid->ssid, ssid->ssid_len);
 213
 214         brcmf_dbg(SCAN, "adding ssid=%.32s (active=%d)\n", ssid->ssid, active);
 215         err = brcmf_fil_iovar_data_set(ifp, "pfn_add", &pfn, sizeof(pfn));
 216         if (err < 0)
 217                 bphy_err(drvr, "adding failed: err=%d\n", err);
 218         return err;
 219 }
 220
 221 static int brcmf_pno_add_bssid(struct brcmf_if *ifp, const u8 *bssid)
 222 {
 223         struct brcmf_pub *drvr = ifp->drvr;
 224         struct brcmf_pno_bssid_le bssid_cfg;
 225         int err;
 226
 227         memcpy(bssid_cfg.bssid, bssid, ETH_ALEN);
 228         bssid_cfg.flags = 0;
 229
 230         brcmf_dbg(SCAN, "adding bssid=%pM\n", bssid);
 231         err = brcmf_fil_iovar_data_set(ifp, "pfn_add_bssid", &bssid_cfg,
 232                                        sizeof(bssid_cfg));
 233         if (err < 0)
 234                 bphy_err(drvr, "adding failed: err=%d\n", err);
 235         return err;
 236 }
 237
 238 static bool brcmf_is_ssid_active(struct cfg80211_ssid *ssid,
 239                                  struct cfg80211_sched_scan_request *req)
 240 {
 241         int i;
 242
 243         if (!ssid || !req->ssids || !req->n_ssids)
 244                 return false;
 245
 246         for (i = 0; i < req->n_ssids; i++) {
 247                 if (ssid->ssid_len == req->ssids[i].ssid_len) {
 248                         if (!strncmp(ssid->ssid, req->ssids[i].ssid,
 249                                      ssid->ssid_len))
 250                                 return true;
 251                 }
 252         }
 253         return false;
 254 }
 255
 256 static int brcmf_pno_clean(struct brcmf_if *ifp)
 257 {
 258         struct brcmf_pub *drvr = ifp->drvr;
 259         int ret;
 260
 261         /* Disable pfn */
 262         ret = brcmf_fil_iovar_int_set(ifp, "pfn", 0);
 263         if (ret == 0) {
 264                 /* clear pfn */
 265                 ret = brcmf_fil_iovar_data_set(ifp, "pfnclear", NULL, 0);
 266         }
 267         if (ret < 0)
 268                 bphy_err(drvr, "failed code %d\n", ret);
 269
 270         return ret;
 271 }
 272
 273 static int brcmf_pno_get_bucket_channels(struct cfg80211_sched_scan_request *r,
 274                                          struct brcmf_pno_config_le *pno_cfg)
 275 {
 276         u32 n_chan = le32_to_cpu(pno_cfg->channel_num);
 277         u16 chan;
 278         int i, err = 0;
 279
 280         for (i = 0; i < r->n_channels; i++) {
 281                 if (n_chan >= BRCMF_NUMCHANNELS) {
 282                         err = -ENOSPC;
 283                         goto done;
 284                 }
 285                 chan = r->channels[i]->hw_value;
 286                 brcmf_dbg(SCAN, "[%d] Chan : %u\n", n_chan, chan);
 287                 pno_cfg->channel_list[n_chan++] = cpu_to_le16(chan);
 288         }
 289         /* return number of channels */
 290         err = n_chan;
 291 done:
 292         pno_cfg->channel_num = cpu_to_le32(n_chan);
 293         return err;
 294 }
 295
 296 static int brcmf_pno_prep_fwconfig(struct brcmf_pno_info *pi,
 297                                    struct brcmf_pno_config_le *pno_cfg,
 298                                    struct brcmf_gscan_bucket_config **buckets,
 299                                    u32 *scan_freq)
 300 {
 301         struct cfg80211_sched_scan_request *sr;
 302         struct brcmf_gscan_bucket_config *fw_buckets;
 303         int i, err, chidx;
 304
 305         brcmf_dbg(SCAN, "n_reqs=%d\n", pi->n_reqs);
 306         if (WARN_ON(!pi->n_reqs))
 307                 return -ENODATA;
 308
 309         /*
 310          * actual scan period is determined using gcd() for each
 311          * scheduled scan period.
 312          */
 313         *scan_freq = pi->reqs[0]->scan_plans[0].interval;
 314         for (i = 1; i < pi->n_reqs; i++) {
 315                 sr = pi->reqs[i];
 316                 *scan_freq = gcd(sr->scan_plans[0].interval, *scan_freq);
 317         }
 318         if (*scan_freq < BRCMF_PNO_SCHED_SCAN_MIN_PERIOD) {
 319                 brcmf_dbg(SCAN, "scan period too small, using minimum\n");
 320                 *scan_freq = BRCMF_PNO_SCHED_SCAN_MIN_PERIOD;
 321         }
 322
 323         *buckets = NULL;
 324         fw_buckets = kcalloc(pi->n_reqs, sizeof(*fw_buckets), GFP_KERNEL);
 325         if (!fw_buckets)
 326                 return -ENOMEM;
 327
 328         memset(pno_cfg, 0, sizeof(*pno_cfg));
 329         for (i = 0; i < pi->n_reqs; i++) {
 330                 sr = pi->reqs[i];
 331                 chidx = brcmf_pno_get_bucket_channels(sr, pno_cfg);
 332                 if (chidx < 0) {
 333                         err = chidx;
 334                         goto fail;
 335                 }
 336                 fw_buckets[i].bucket_end_index = chidx - 1;
 337                 fw_buckets[i].bucket_freq_multiple =
 338                         sr->scan_plans[0].interval / *scan_freq;
 339                 /* assure period is non-zero */
 340                 if (!fw_buckets[i].bucket_freq_multiple)
 341                         fw_buckets[i].bucket_freq_multiple = 1;
 342                 fw_buckets[i].flag = BRCMF_PNO_REPORT_NO_BATCH;
 343         }
 344
 345         if (BRCMF_SCAN_ON()) {
 346                 brcmf_err("base period=%u\n", *scan_freq);
 347                 for (i = 0; i < pi->n_reqs; i++) {
 348                         brcmf_err("[%d] period %u max %u repeat %u flag %x idx %u\n",
 349                                   i, fw_buckets[i].bucket_freq_multiple,
 350                                   le16_to_cpu(fw_buckets[i].max_freq_multiple),
 351                                   fw_buckets[i].repeat, fw_buckets[i].flag,
 352                                   fw_buckets[i].bucket_end_index);
 353                 }
 354         }
 355         *buckets = fw_buckets;
 356         return pi->n_reqs;
 357
 358 fail:
 359         kfree(fw_buckets);
 360         return err;
 361 }
 362
 363 static int brcmf_pno_config_networks(struct brcmf_if *ifp,
 364                                      struct brcmf_pno_info *pi)
 365 {
 366         struct cfg80211_sched_scan_request *r;
 367         struct cfg80211_match_set *ms;
 368         bool active;
 369         int i, j, err = 0;
 370
 371         for (i = 0; i < pi->n_reqs; i++) {
 372                 r = pi->reqs[i];
 373
 374                 for (j = 0; j < r->n_match_sets; j++) {
 375                         ms = &r->match_sets[j];
 376                         if (ms->ssid.ssid_len) {
 377                                 active = brcmf_is_ssid_active(&ms->ssid, r);
 378                                 err = brcmf_pno_add_ssid(ifp, &ms->ssid,
 379                                                          active);
 380                         }
 381                         if (!err && is_valid_ether_addr(ms->bssid))
 382                                 err = brcmf_pno_add_bssid(ifp, ms->bssid);
 383
 384                         if (err < 0)
 385                                 return err;
 386                 }
 387         }
 388         return 0;
 389 }
 390
 391 static int brcmf_pno_config_sched_scans(struct brcmf_if *ifp)
 392 {
 393         struct brcmf_pub *drvr = ifp->drvr;
 394         struct brcmf_pno_info *pi;
 395         struct brcmf_gscan_config *gscan_cfg;
 396         struct brcmf_gscan_bucket_config *buckets;
 397         struct brcmf_pno_config_le pno_cfg;
 398         size_t gsz;
 399         u32 scan_freq;
 400         int err, n_buckets;
 401
 402         pi = ifp_to_pno(ifp);
 403         n_buckets = brcmf_pno_prep_fwconfig(pi, &pno_cfg, &buckets,
 404                                             &scan_freq);
 405         if (n_buckets < 0)
 406                 return n_buckets;
 407
 408         gsz = sizeof(*gscan_cfg) + (n_buckets - 1) * sizeof(*buckets);
 409         gscan_cfg = kzalloc(gsz, GFP_KERNEL);
 410         if (!gscan_cfg) {
 411                 err = -ENOMEM;
 412                 goto free_buckets;
 413         }
 414
 415         /* clean up everything */
 416         err = brcmf_pno_clean(ifp);
 417         if  (err < 0) {
 418                 bphy_err(drvr, "failed error=%d\n", err);
 419                 goto free_gscan;
 420         }
 421
 422         /* configure pno */
 423         err = brcmf_pno_config(ifp, scan_freq, 0, 0);
 424         if (err < 0)
 425                 goto free_gscan;
 426
 427         err = brcmf_pno_channel_config(ifp, &pno_cfg);
 428         if (err < 0)
 429                 goto clean;
 430
 431         gscan_cfg->version = cpu_to_le16(BRCMF_GSCAN_CFG_VERSION);
 432         gscan_cfg->retry_threshold = GSCAN_RETRY_THRESHOLD;
 433         gscan_cfg->buffer_threshold = GSCAN_BATCH_NO_THR_SET;
 434         gscan_cfg->flags = BRCMF_GSCAN_CFG_ALL_BUCKETS_IN_1ST_SCAN;
 435
 436         gscan_cfg->count_of_channel_buckets = n_buckets;
 437         memcpy(&gscan_cfg->bucket[0], buckets,
 438                n_buckets * sizeof(*buckets));
 439
 440         err = brcmf_fil_iovar_data_set(ifp, "pfn_gscan_cfg", gscan_cfg, gsz);
 441
 442         if (err < 0)
 443                 goto clean;
 444
 445         /* configure random mac */
 446         err = brcmf_pno_set_random(ifp, pi);
 447         if (err < 0)
 448                 goto clean;
 449
 450         err = brcmf_pno_config_networks(ifp, pi);
 451         if (err < 0)
 452                 goto clean;
 453
 454         /* Enable the PNO */
 455         err = brcmf_fil_iovar_int_set(ifp, "pfn", 1);
 456
 457 clean:
 458         if (err < 0)
 459                 brcmf_pno_clean(ifp);
 460 free_gscan:
 461         kfree(gscan_cfg);
 462 free_buckets:
 463         kfree(buckets);
 464         return err;
 465 }
 466
 467 int brcmf_pno_start_sched_scan(struct brcmf_if *ifp,
 468                                struct cfg80211_sched_scan_request *req)
 469 {
 470         struct brcmf_pno_info *pi;
 471         int ret;
 472
 473         brcmf_dbg(TRACE, "reqid=%llu\n", req->reqid);
 474
 475         pi = ifp_to_pno(ifp);
 476         ret = brcmf_pno_store_request(pi, req);
 477         if (ret < 0)
 478                 return ret;
 479
 480         ret = brcmf_pno_config_sched_scans(ifp);
 481         if (ret < 0) {
 482                 brcmf_pno_remove_request(pi, req->reqid);
 483                 if (pi->n_reqs)
 484                         (void)brcmf_pno_config_sched_scans(ifp);
 485                 return ret;
 486         }
 487         return 0;
 488 }
 489
 490 int brcmf_pno_stop_sched_scan(struct brcmf_if *ifp, u64 reqid)
 491 {
 492         struct brcmf_pno_info *pi;
 493         int err;
 494
 495         brcmf_dbg(TRACE, "reqid=%llu\n", reqid);
 496
 497         pi = ifp_to_pno(ifp);
 498
 499         /* No PNO request */
 500         if (!pi->n_reqs)
 501                 return 0;
 502
 503         err = brcmf_pno_remove_request(pi, reqid);
 504         if (err)
 505                 return err;
 506
 507         brcmf_pno_clean(ifp);
 508
 509         if (pi->n_reqs)
 510                 (void)brcmf_pno_config_sched_scans(ifp);
 511
 512         return 0;
 513 }
 514
 515 int brcmf_pno_attach(struct brcmf_cfg80211_info *cfg)
 516 {
 517         struct brcmf_pno_info *pi;
 518
 519         brcmf_dbg(TRACE, "enter\n");
 520         pi = kzalloc(sizeof(*pi), GFP_KERNEL);
 521         if (!pi)
 522                 return -ENOMEM;
 523
 524         cfg->pno = pi;
 525         mutex_init(&pi->req_lock);
 526         return 0;
 527 }
 528
 529 void brcmf_pno_detach(struct brcmf_cfg80211_info *cfg)
 530 {
 531         struct brcmf_pno_info *pi;
 532
 533         brcmf_dbg(TRACE, "enter\n");
 534         pi = cfg->pno;
 535         cfg->pno = NULL;
 536
 537         WARN_ON(pi->n_reqs);
 538         mutex_destroy(&pi->req_lock);
 539         kfree(pi);
 540 }
 541
 542 void brcmf_pno_wiphy_params(struct wiphy *wiphy, bool gscan)
 543 {
 544         /* scheduled scan settings */
 545         wiphy->max_sched_scan_reqs = gscan ? BRCMF_PNO_MAX_BUCKETS : 1;
 546         wiphy->max_sched_scan_ssids = BRCMF_PNO_MAX_PFN_COUNT;
 547         wiphy->max_match_sets = BRCMF_PNO_MAX_PFN_COUNT;
 548         wiphy->max_sched_scan_ie_len = BRCMF_SCAN_IE_LEN_MAX;
 549         wiphy->max_sched_scan_plan_interval = BRCMF_PNO_SCHED_SCAN_MAX_PERIOD;
 550 }
 551
 552 u64 brcmf_pno_find_reqid_by_bucket(struct brcmf_pno_info *pi, u32 bucket)
 553 {
 554         u64 reqid = 0;
 555
 556         mutex_lock(&pi->req_lock);
 557
 558         if (bucket < pi->n_reqs)
 559                 reqid = pi->reqs[bucket]->reqid;
 560
 561         mutex_unlock(&pi->req_lock);
 562         return reqid;
 563 }
 564
 565 u32 brcmf_pno_get_bucket_map(struct brcmf_pno_info *pi,
 566                              struct brcmf_pno_net_info_le *ni)
 567 {
 568         struct cfg80211_sched_scan_request *req;
 569         struct cfg80211_match_set *ms;
 570         u32 bucket_map = 0;
 571         int i, j;
 572
 573         mutex_lock(&pi->req_lock);
 574         for (i = 0; i < pi->n_reqs; i++) {
 575                 req = pi->reqs[i];
 576
 577                 if (!req->n_match_sets)
 578                         continue;
 579                 for (j = 0; j < req->n_match_sets; j++) {
 580                         ms = &req->match_sets[j];
 581                         if (ms->ssid.ssid_len == ni->SSID_len &&
 582                             !memcmp(ms->ssid.ssid, ni->SSID, ni->SSID_len)) {
 583                                 bucket_map |= BIT(i);
 584                                 break;
 585                         }
 586                         if (is_valid_ether_addr(ms->bssid) &&
 587                             !memcmp(ms->bssid, ni->bssid, ETH_ALEN)) {
 588                                 bucket_map |= BIT(i);
 589                                 break;
 590                         }
 591                 }
 592         }
 593         mutex_unlock(&pi->req_lock);
 594         return bucket_map;
 595 }