drivers/net/sfc/filter.c

   1 /****************************************************************************
   2  * Driver for Solarflare Solarstorm network controllers and boards
   3  * Copyright 2005-2010 Solarflare Communications Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published
   7  * by the Free Software Foundation, incorporated herein by reference.
   8  */
   9
  10 #include "efx.h"
  11 #include "filter.h"
  12 #include "io.h"
  13 #include "nic.h"
  14 #include "regs.h"
  15
  16 /* "Fudge factors" - difference between programmed value and actual depth.
  17  * Due to pipelined implementation we need to program H/W with a value that
  18  * is larger than the hop limit we want.
  19  */
  20 #define FILTER_CTL_SRCH_FUDGE_WILD 3
  21 #define FILTER_CTL_SRCH_FUDGE_FULL 1
  22
  23 /* Hard maximum hop limit.  Hardware will time-out beyond 200-something.
  24  * We also need to avoid infinite loops in efx_filter_search() when the
  25  * table is full.
  26  */
  27 #define FILTER_CTL_SRCH_MAX 200
  28
  29 struct efx_filter_table {
  30         u32             offset;         /* address of table relative to BAR */
  31         unsigned        size;           /* number of entries */
  32         unsigned        step;           /* step between entries */
  33         unsigned        used;           /* number currently used */
  34         unsigned long   *used_bitmap;
  35         struct efx_filter_spec *spec;
  36 };
  37
  38 struct efx_filter_state {
  39         spinlock_t      lock;
  40         struct efx_filter_table table[EFX_FILTER_TABLE_COUNT];
  41         unsigned        search_depth[EFX_FILTER_TYPE_COUNT];
  42 };
  43
  44 /* The filter hash function is LFSR polynomial x^16 + x^3 + 1 of a 32-bit
  45  * key derived from the n-tuple.  The initial LFSR state is 0xffff. */
  46 static u16 efx_filter_hash(u32 key)
  47 {
  48         u16 tmp;
  49
  50         /* First 16 rounds */
  51         tmp = 0x1fff ^ key >> 16;
  52         tmp = tmp ^ tmp >> 3 ^ tmp >> 6;
  53         tmp = tmp ^ tmp >> 9;
  54         /* Last 16 rounds */
  55         tmp = tmp ^ tmp << 13 ^ key;
  56         tmp = tmp ^ tmp >> 3 ^ tmp >> 6;
  57         return tmp ^ tmp >> 9;
  58 }
  59
  60 /* To allow for hash collisions, filter search continues at these
  61  * increments from the first possible entry selected by the hash. */
  62 static u16 efx_filter_increment(u32 key)
  63 {
  64         return key * 2 - 1;
  65 }
  66
  67 static enum efx_filter_table_id
  68 efx_filter_type_table_id(enum efx_filter_type type)
  69 {
  70         BUILD_BUG_ON(EFX_FILTER_TABLE_RX_IP != (EFX_FILTER_RX_TCP_FULL >> 2));
  71         BUILD_BUG_ON(EFX_FILTER_TABLE_RX_IP != (EFX_FILTER_RX_TCP_WILD >> 2));
  72         BUILD_BUG_ON(EFX_FILTER_TABLE_RX_IP != (EFX_FILTER_RX_UDP_FULL >> 2));
  73         BUILD_BUG_ON(EFX_FILTER_TABLE_RX_IP != (EFX_FILTER_RX_UDP_WILD >> 2));
  74         BUILD_BUG_ON(EFX_FILTER_TABLE_RX_MAC != (EFX_FILTER_RX_MAC_FULL >> 2));
  75         BUILD_BUG_ON(EFX_FILTER_TABLE_RX_MAC != (EFX_FILTER_RX_MAC_WILD >> 2));
  76         return type >> 2;
  77 }
  78
  79 static void
  80 efx_filter_table_reset_search_depth(struct efx_filter_state *state,
  81                                     enum efx_filter_table_id table_id)
  82 {
  83         memset(state->search_depth + (table_id << 2), 0,
  84                sizeof(state->search_depth[0]) << 2);
  85 }
  86
  87 static void efx_filter_push_rx_limits(struct efx_nic *efx)
  88 {
  89         struct efx_filter_state *state = efx->filter_state;
  90         efx_oword_t filter_ctl;
  91
  92         efx_reado(efx, &filter_ctl, FR_BZ_RX_FILTER_CTL);
  93
  94         EFX_SET_OWORD_FIELD(filter_ctl, FRF_BZ_TCP_FULL_SRCH_LIMIT,
  95                             state->search_depth[EFX_FILTER_RX_TCP_FULL] +
  96                             FILTER_CTL_SRCH_FUDGE_FULL);
  97         EFX_SET_OWORD_FIELD(filter_ctl, FRF_BZ_TCP_WILD_SRCH_LIMIT,
  98                             state->search_depth[EFX_FILTER_RX_TCP_WILD] +
  99                             FILTER_CTL_SRCH_FUDGE_WILD);
 100         EFX_SET_OWORD_FIELD(filter_ctl, FRF_BZ_UDP_FULL_SRCH_LIMIT,
 101                             state->search_depth[EFX_FILTER_RX_UDP_FULL] +
 102                             FILTER_CTL_SRCH_FUDGE_FULL);
 103         EFX_SET_OWORD_FIELD(filter_ctl, FRF_BZ_UDP_WILD_SRCH_LIMIT,
 104                             state->search_depth[EFX_FILTER_RX_UDP_WILD] +
 105                             FILTER_CTL_SRCH_FUDGE_WILD);
 106
 107         if (state->table[EFX_FILTER_TABLE_RX_MAC].size) {
 108                 EFX_SET_OWORD_FIELD(
 109                         filter_ctl, FRF_CZ_ETHERNET_FULL_SEARCH_LIMIT,
 110                         state->search_depth[EFX_FILTER_RX_MAC_FULL] +
 111                         FILTER_CTL_SRCH_FUDGE_FULL);
 112                 EFX_SET_OWORD_FIELD(
 113                         filter_ctl, FRF_CZ_ETHERNET_WILDCARD_SEARCH_LIMIT,
 114                         state->search_depth[EFX_FILTER_RX_MAC_WILD] +
 115                         FILTER_CTL_SRCH_FUDGE_WILD);
 116         }
 117
 118         efx_writeo(efx, &filter_ctl, FR_BZ_RX_FILTER_CTL);
 119 }
 120
 121 /* Build a filter entry and return its n-tuple key. */
 122 static u32 efx_filter_build(efx_oword_t *filter, struct efx_filter_spec *spec)
 123 {
 124         u32 data3;
 125
 126         switch (efx_filter_type_table_id(spec->type)) {
 127         case EFX_FILTER_TABLE_RX_IP: {
 128                 bool is_udp = (spec->type == EFX_FILTER_RX_UDP_FULL ||
 129                                spec->type == EFX_FILTER_RX_UDP_WILD);
 130                 EFX_POPULATE_OWORD_7(
 131                         *filter,
 132                         FRF_BZ_RSS_EN,
 133                         !!(spec->flags & EFX_FILTER_FLAG_RX_RSS),
 134                         FRF_BZ_SCATTER_EN,
 135                         !!(spec->flags & EFX_FILTER_FLAG_RX_SCATTER),
 136                         FRF_BZ_TCP_UDP, is_udp,
 137                         FRF_BZ_RXQ_ID, spec->dmaq_id,
 138                         EFX_DWORD_2, spec->data[2],
 139                         EFX_DWORD_1, spec->data[1],
 140                         EFX_DWORD_0, spec->data[0]);
 141                 data3 = is_udp;
 142                 break;
 143         }
 144
 145         case EFX_FILTER_TABLE_RX_MAC: {
 146                 bool is_wild = spec->type == EFX_FILTER_RX_MAC_WILD;
 147                 EFX_POPULATE_OWORD_8(
 148                         *filter,
 149                         FRF_CZ_RMFT_RSS_EN,
 150                         !!(spec->flags & EFX_FILTER_FLAG_RX_RSS),
 151                         FRF_CZ_RMFT_SCATTER_EN,
 152                         !!(spec->flags & EFX_FILTER_FLAG_RX_SCATTER),
 153                         FRF_CZ_RMFT_IP_OVERRIDE,
 154                         !!(spec->flags & EFX_FILTER_FLAG_RX_OVERRIDE_IP),
 155                         FRF_CZ_RMFT_RXQ_ID, spec->dmaq_id,
 156                         FRF_CZ_RMFT_WILDCARD_MATCH, is_wild,
 157                         FRF_CZ_RMFT_DEST_MAC_HI, spec->data[2],
 158                         FRF_CZ_RMFT_DEST_MAC_LO, spec->data[1],
 159                         FRF_CZ_RMFT_VLAN_ID, spec->data[0]);
 160                 data3 = is_wild;
 161                 break;
 162         }
 163
 164         default:
 165                 BUG();
 166         }
 167
 168         return spec->data[0] ^ spec->data[1] ^ spec->data[2] ^ data3;
 169 }
 170
 171 static bool efx_filter_equal(const struct efx_filter_spec *left,
 172                              const struct efx_filter_spec *right)
 173 {
 174         if (left->type != right->type ||
 175             memcmp(left->data, right->data, sizeof(left->data)))
 176                 return false;
 177
 178         return true;
 179 }
 180
 181 static int efx_filter_search(struct efx_filter_table *table,
 182                              struct efx_filter_spec *spec, u32 key,
 183                              bool for_insert, int *depth_required)
 184 {
 185         unsigned hash, incr, filter_idx, depth;
 186         struct efx_filter_spec *cmp;
 187
 188         hash = efx_filter_hash(key);
 189         incr = efx_filter_increment(key);
 190
 191         for (depth = 1, filter_idx = hash & (table->size - 1);
 192              depth <= FILTER_CTL_SRCH_MAX &&
 193                      test_bit(filter_idx, table->used_bitmap);
 194              ++depth) {
 195                 cmp = &table->spec[filter_idx];
 196                 if (efx_filter_equal(spec, cmp))
 197                         goto found;
 198                 filter_idx = (filter_idx + incr) & (table->size - 1);
 199         }
 200         if (!for_insert)
 201                 return -ENOENT;
 202         if (depth > FILTER_CTL_SRCH_MAX)
 203                 return -EBUSY;
 204 found:
 205         *depth_required = depth;
 206         return filter_idx;
 207 }
 208
 209 /**
 210  * efx_filter_insert_filter - add or replace a filter
 211  * @efx: NIC in which to insert the filter
 212  * @spec: Specification for the filter
 213  * @replace: Flag for whether the specified filter may replace a filter
 214  *      with an identical match expression and equal or lower priority
 215  *
 216  * On success, return the filter index within its table.
 217  * On failure, return a negative error code.
 218  */
 219 int efx_filter_insert_filter(struct efx_nic *efx, struct efx_filter_spec *spec,
 220                              bool replace)
 221 {
 222         struct efx_filter_state *state = efx->filter_state;
 223         enum efx_filter_table_id table_id =
 224                 efx_filter_type_table_id(spec->type);
 225         struct efx_filter_table *table = &state->table[table_id];
 226         struct efx_filter_spec *saved_spec;
 227         efx_oword_t filter;
 228         int filter_idx, depth;
 229         u32 key;
 230         int rc;
 231
 232         if (table->size == 0)
 233                 return -EINVAL;
 234
 235         key = efx_filter_build(&filter, spec);
 236
 237         netif_vdbg(efx, hw, efx->net_dev,
 238                    "%s: type %d search_depth=%d", __func__, spec->type,
 239                    state->search_depth[spec->type]);
 240
 241         spin_lock_bh(&state->lock);
 242
 243         rc = efx_filter_search(table, spec, key, true, &depth);
 244         if (rc < 0)
 245                 goto out;
 246         filter_idx = rc;
 247         BUG_ON(filter_idx >= table->size);
 248         saved_spec = &table->spec[filter_idx];
 249
 250         if (test_bit(filter_idx, table->used_bitmap)) {
 251                 /* Should we replace the existing filter? */
 252                 if (!replace) {
 253                         rc = -EEXIST;
 254                         goto out;
 255                 }
 256                 if (spec->priority < saved_spec->priority) {
 257                         rc = -EPERM;
 258                         goto out;
 259                 }
 260         } else {
 261                 __set_bit(filter_idx, table->used_bitmap);
 262                 ++table->used;
 263         }
 264         *saved_spec = *spec;
 265
 266         if (state->search_depth[spec->type] < depth) {
 267                 state->search_depth[spec->type] = depth;
 268                 efx_filter_push_rx_limits(efx);
 269         }
 270
 271         efx_writeo(efx, &filter, table->offset + table->step * filter_idx);
 272
 273         netif_vdbg(efx, hw, efx->net_dev,
 274                    "%s: filter type %d index %d rxq %u set",
 275                    __func__, spec->type, filter_idx, spec->dmaq_id);
 276
 277 out:
 278         spin_unlock_bh(&state->lock);
 279         return rc;
 280 }
 281
 282 static void efx_filter_table_clear_entry(struct efx_nic *efx,
 283                                          struct efx_filter_table *table,
 284                                          int filter_idx)
 285 {
 286         static efx_oword_t filter;
 287
 288         if (test_bit(filter_idx, table->used_bitmap)) {
 289                 __clear_bit(filter_idx, table->used_bitmap);
 290                 --table->used;
 291                 memset(&table->spec[filter_idx], 0, sizeof(table->spec[0]));
 292
 293                 efx_writeo(efx, &filter,
 294                            table->offset + table->step * filter_idx);
 295         }
 296 }
 297
 298 /**
 299  * efx_filter_remove_filter - remove a filter by specification
 300  * @efx: NIC from which to remove the filter
 301  * @spec: Specification for the filter
 302  *
 303  * On success, return zero.
 304  * On failure, return a negative error code.
 305  */
 306 int efx_filter_remove_filter(struct efx_nic *efx, struct efx_filter_spec *spec)
 307 {
 308         struct efx_filter_state *state = efx->filter_state;
 309         enum efx_filter_table_id table_id =
 310                 efx_filter_type_table_id(spec->type);
 311         struct efx_filter_table *table = &state->table[table_id];
 312         struct efx_filter_spec *saved_spec;
 313         efx_oword_t filter;
 314         int filter_idx, depth;
 315         u32 key;
 316         int rc;
 317
 318         key = efx_filter_build(&filter, spec);
 319
 320         spin_lock_bh(&state->lock);
 321
 322         rc = efx_filter_search(table, spec, key, false, &depth);
 323         if (rc < 0)
 324                 goto out;
 325         filter_idx = rc;
 326         saved_spec = &table->spec[filter_idx];
 327
 328         if (spec->priority < saved_spec->priority) {
 329                 rc = -EPERM;
 330                 goto out;
 331         }
 332
 333         efx_filter_table_clear_entry(efx, table, filter_idx);
 334         if (table->used == 0)
 335                 efx_filter_table_reset_search_depth(state, table_id);
 336         rc = 0;
 337
 338 out:
 339         spin_unlock_bh(&state->lock);
 340         return rc;
 341 }
 342
 343 /**
 344  * efx_filter_table_clear - remove filters from a table by priority
 345  * @efx: NIC from which to remove the filters
 346  * @table_id: Table from which to remove the filters
 347  * @priority: Maximum priority to remove
 348  */
 349 void efx_filter_table_clear(struct efx_nic *efx,
 350                             enum efx_filter_table_id table_id,
 351                             enum efx_filter_priority priority)
 352 {
 353         struct efx_filter_state *state = efx->filter_state;
 354         struct efx_filter_table *table = &state->table[table_id];
 355         int filter_idx;
 356
 357         spin_lock_bh(&state->lock);
 358
 359         for (filter_idx = 0; filter_idx < table->size; ++filter_idx)
 360                 if (table->spec[filter_idx].priority <= priority)
 361                         efx_filter_table_clear_entry(efx, table, filter_idx);
 362         if (table->used == 0)
 363                 efx_filter_table_reset_search_depth(state, table_id);
 364
 365         spin_unlock_bh(&state->lock);
 366 }
 367
 368 /* Restore filter stater after reset */
 369 void efx_restore_filters(struct efx_nic *efx)
 370 {
 371         struct efx_filter_state *state = efx->filter_state;
 372         enum efx_filter_table_id table_id;
 373         struct efx_filter_table *table;
 374         efx_oword_t filter;
 375         int filter_idx;
 376
 377         spin_lock_bh(&state->lock);
 378
 379         for (table_id = 0; table_id < EFX_FILTER_TABLE_COUNT; table_id++) {
 380                 table = &state->table[table_id];
 381                 for (filter_idx = 0; filter_idx < table->size; filter_idx++) {
 382                         if (!test_bit(filter_idx, table->used_bitmap))
 383                                 continue;
 384                         efx_filter_build(&filter, &table->spec[filter_idx]);
 385                         efx_writeo(efx, &filter,
 386                                    table->offset + table->step * filter_idx);
 387                 }
 388         }
 389
 390         efx_filter_push_rx_limits(efx);
 391
 392         spin_unlock_bh(&state->lock);
 393 }
 394
 395 int efx_probe_filters(struct efx_nic *efx)
 396 {
 397         struct efx_filter_state *state;
 398         struct efx_filter_table *table;
 399         unsigned table_id;
 400
 401         state = kzalloc(sizeof(*efx->filter_state), GFP_KERNEL);
 402         if (!state)
 403                 return -ENOMEM;
 404         efx->filter_state = state;
 405
 406         spin_lock_init(&state->lock);
 407
 408         if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0) {
 409                 table = &state->table[EFX_FILTER_TABLE_RX_IP];
 410                 table->offset = FR_BZ_RX_FILTER_TBL0;
 411                 table->size = FR_BZ_RX_FILTER_TBL0_ROWS;
 412                 table->step = FR_BZ_RX_FILTER_TBL0_STEP;
 413         }
 414
 415         if (efx_nic_rev(efx) >= EFX_REV_SIENA_A0) {
 416                 table = &state->table[EFX_FILTER_TABLE_RX_MAC];
 417                 table->offset = FR_CZ_RX_MAC_FILTER_TBL0;
 418                 table->size = FR_CZ_RX_MAC_FILTER_TBL0_ROWS;
 419                 table->step = FR_CZ_RX_MAC_FILTER_TBL0_STEP;
 420         }
 421
 422         for (table_id = 0; table_id < EFX_FILTER_TABLE_COUNT; table_id++) {
 423                 table = &state->table[table_id];
 424                 if (table->size == 0)
 425                         continue;
 426                 table->used_bitmap = kcalloc(BITS_TO_LONGS(table->size),
 427                                              sizeof(unsigned long),
 428                                              GFP_KERNEL);
 429                 if (!table->used_bitmap)
 430                         goto fail;
 431                 table->spec = vmalloc(table->size * sizeof(*table->spec));
 432                 if (!table->spec)
 433                         goto fail;
 434                 memset(table->spec, 0, table->size * sizeof(*table->spec));
 435         }
 436
 437         return 0;
 438
 439 fail:
 440         efx_remove_filters(efx);
 441         return -ENOMEM;
 442 }
 443
 444 void efx_remove_filters(struct efx_nic *efx)
 445 {
 446         struct efx_filter_state *state = efx->filter_state;
 447         enum efx_filter_table_id table_id;
 448
 449         for (table_id = 0; table_id < EFX_FILTER_TABLE_COUNT; table_id++) {
 450                 kfree(state->table[table_id].used_bitmap);
 451                 vfree(state->table[table_id].spec);
 452         }
 453         kfree(state);
 454 }