linux/drivers/net/ethernet/netronome/nfp/bpf/offload.c
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   1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2/* Copyright (C) 2016-2018 Netronome Systems, Inc. */
   3
   4/*
   5 * nfp_net_offload.c
   6 * Netronome network device driver: TC offload functions for PF and VF
   7 */
   8
   9#define pr_fmt(fmt)     "NFP net bpf: " fmt
  10
  11#include <linux/bpf.h>
  12#include <linux/kernel.h>
  13#include <linux/netdevice.h>
  14#include <linux/pci.h>
  15#include <linux/jiffies.h>
  16#include <linux/timer.h>
  17#include <linux/list.h>
  18#include <linux/mm.h>
  19
  20#include <net/pkt_cls.h>
  21#include <net/tc_act/tc_gact.h>
  22#include <net/tc_act/tc_mirred.h>
  23
  24#include "main.h"
  25#include "../ccm.h"
  26#include "../nfp_app.h"
  27#include "../nfp_net_ctrl.h"
  28#include "../nfp_net.h"
  29
  30static int
  31nfp_map_ptr_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog,
  32                   struct bpf_map *map)
  33{
  34        struct nfp_bpf_neutral_map *record;
  35        int err;
  36
  37        /* Reuse path - other offloaded program is already tracking this map. */
  38        record = rhashtable_lookup_fast(&bpf->maps_neutral, &map->id,
  39                                        nfp_bpf_maps_neutral_params);
  40        if (record) {
  41                nfp_prog->map_records[nfp_prog->map_records_cnt++] = record;
  42                record->count++;
  43                return 0;
  44        }
  45
  46        /* Grab a single ref to the map for our record.  The prog destroy ndo
  47         * happens after free_used_maps().
  48         */
  49        map = bpf_map_inc(map, false);
  50        if (IS_ERR(map))
  51                return PTR_ERR(map);
  52
  53        record = kmalloc(sizeof(*record), GFP_KERNEL);
  54        if (!record) {
  55                err = -ENOMEM;
  56                goto err_map_put;
  57        }
  58
  59        record->ptr = map;
  60        record->map_id = map->id;
  61        record->count = 1;
  62
  63        err = rhashtable_insert_fast(&bpf->maps_neutral, &record->l,
  64                                     nfp_bpf_maps_neutral_params);
  65        if (err)
  66                goto err_free_rec;
  67
  68        nfp_prog->map_records[nfp_prog->map_records_cnt++] = record;
  69
  70        return 0;
  71
  72err_free_rec:
  73        kfree(record);
  74err_map_put:
  75        bpf_map_put(map);
  76        return err;
  77}
  78
  79static void
  80nfp_map_ptrs_forget(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog)
  81{
  82        bool freed = false;
  83        int i;
  84
  85        for (i = 0; i < nfp_prog->map_records_cnt; i++) {
  86                if (--nfp_prog->map_records[i]->count) {
  87                        nfp_prog->map_records[i] = NULL;
  88                        continue;
  89                }
  90
  91                WARN_ON(rhashtable_remove_fast(&bpf->maps_neutral,
  92                                               &nfp_prog->map_records[i]->l,
  93                                               nfp_bpf_maps_neutral_params));
  94                freed = true;
  95        }
  96
  97        if (freed) {
  98                synchronize_rcu();
  99
 100                for (i = 0; i < nfp_prog->map_records_cnt; i++)
 101                        if (nfp_prog->map_records[i]) {
 102                                bpf_map_put(nfp_prog->map_records[i]->ptr);
 103                                kfree(nfp_prog->map_records[i]);
 104                        }
 105        }
 106
 107        kfree(nfp_prog->map_records);
 108        nfp_prog->map_records = NULL;
 109        nfp_prog->map_records_cnt = 0;
 110}
 111
 112static int
 113nfp_map_ptrs_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog,
 114                    struct bpf_prog *prog)
 115{
 116        int i, cnt, err;
 117
 118        /* Quickly count the maps we will have to remember */
 119        cnt = 0;
 120        for (i = 0; i < prog->aux->used_map_cnt; i++)
 121                if (bpf_map_offload_neutral(prog->aux->used_maps[i]))
 122                        cnt++;
 123        if (!cnt)
 124                return 0;
 125
 126        nfp_prog->map_records = kmalloc_array(cnt,
 127                                              sizeof(nfp_prog->map_records[0]),
 128                                              GFP_KERNEL);
 129        if (!nfp_prog->map_records)
 130                return -ENOMEM;
 131
 132        for (i = 0; i < prog->aux->used_map_cnt; i++)
 133                if (bpf_map_offload_neutral(prog->aux->used_maps[i])) {
 134                        err = nfp_map_ptr_record(bpf, nfp_prog,
 135                                                 prog->aux->used_maps[i]);
 136                        if (err) {
 137                                nfp_map_ptrs_forget(bpf, nfp_prog);
 138                                return err;
 139                        }
 140                }
 141        WARN_ON(cnt != nfp_prog->map_records_cnt);
 142
 143        return 0;
 144}
 145
 146static int
 147nfp_prog_prepare(struct nfp_prog *nfp_prog, const struct bpf_insn *prog,
 148                 unsigned int cnt)
 149{
 150        struct nfp_insn_meta *meta;
 151        unsigned int i;
 152
 153        for (i = 0; i < cnt; i++) {
 154                meta = kzalloc(sizeof(*meta), GFP_KERNEL);
 155                if (!meta)
 156                        return -ENOMEM;
 157
 158                meta->insn = prog[i];
 159                meta->n = i;
 160                if (is_mbpf_alu(meta)) {
 161                        meta->umin_src = U64_MAX;
 162                        meta->umin_dst = U64_MAX;
 163                }
 164
 165                list_add_tail(&meta->l, &nfp_prog->insns);
 166        }
 167        nfp_prog->n_insns = cnt;
 168
 169        nfp_bpf_jit_prepare(nfp_prog);
 170
 171        return 0;
 172}
 173
 174static void nfp_prog_free(struct nfp_prog *nfp_prog)
 175{
 176        struct nfp_insn_meta *meta, *tmp;
 177
 178        kfree(nfp_prog->subprog);
 179
 180        list_for_each_entry_safe(meta, tmp, &nfp_prog->insns, l) {
 181                list_del(&meta->l);
 182                kfree(meta);
 183        }
 184        kfree(nfp_prog);
 185}
 186
 187static int nfp_bpf_verifier_prep(struct bpf_prog *prog)
 188{
 189        struct nfp_prog *nfp_prog;
 190        int ret;
 191
 192        nfp_prog = kzalloc(sizeof(*nfp_prog), GFP_KERNEL);
 193        if (!nfp_prog)
 194                return -ENOMEM;
 195        prog->aux->offload->dev_priv = nfp_prog;
 196
 197        INIT_LIST_HEAD(&nfp_prog->insns);
 198        nfp_prog->type = prog->type;
 199        nfp_prog->bpf = bpf_offload_dev_priv(prog->aux->offload->offdev);
 200
 201        ret = nfp_prog_prepare(nfp_prog, prog->insnsi, prog->len);
 202        if (ret)
 203                goto err_free;
 204
 205        nfp_prog->verifier_meta = nfp_prog_first_meta(nfp_prog);
 206
 207        return 0;
 208
 209err_free:
 210        nfp_prog_free(nfp_prog);
 211
 212        return ret;
 213}
 214
 215static int nfp_bpf_translate(struct bpf_prog *prog)
 216{
 217        struct nfp_net *nn = netdev_priv(prog->aux->offload->netdev);
 218        struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
 219        unsigned int max_instr;
 220        int err;
 221
 222        /* We depend on dead code elimination succeeding */
 223        if (prog->aux->offload->opt_failed)
 224                return -EINVAL;
 225
 226        max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
 227        nfp_prog->__prog_alloc_len = max_instr * sizeof(u64);
 228
 229        nfp_prog->prog = kvmalloc(nfp_prog->__prog_alloc_len, GFP_KERNEL);
 230        if (!nfp_prog->prog)
 231                return -ENOMEM;
 232
 233        err = nfp_bpf_jit(nfp_prog);
 234        if (err)
 235                return err;
 236
 237        prog->aux->offload->jited_len = nfp_prog->prog_len * sizeof(u64);
 238        prog->aux->offload->jited_image = nfp_prog->prog;
 239
 240        return nfp_map_ptrs_record(nfp_prog->bpf, nfp_prog, prog);
 241}
 242
 243static void nfp_bpf_destroy(struct bpf_prog *prog)
 244{
 245        struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
 246
 247        kvfree(nfp_prog->prog);
 248        nfp_map_ptrs_forget(nfp_prog->bpf, nfp_prog);
 249        nfp_prog_free(nfp_prog);
 250}
 251
 252/* Atomic engine requires values to be in big endian, we need to byte swap
 253 * the value words used with xadd.
 254 */
 255static void nfp_map_bpf_byte_swap(struct nfp_bpf_map *nfp_map, void *value)
 256{
 257        u32 *word = value;
 258        unsigned int i;
 259
 260        for (i = 0; i < DIV_ROUND_UP(nfp_map->offmap->map.value_size, 4); i++)
 261                if (nfp_map->use_map[i].type == NFP_MAP_USE_ATOMIC_CNT)
 262                        word[i] = (__force u32)cpu_to_be32(word[i]);
 263}
 264
 265/* Mark value as unsafely initialized in case it becomes atomic later
 266 * and we didn't byte swap something non-byte swap neutral.
 267 */
 268static void
 269nfp_map_bpf_byte_swap_record(struct nfp_bpf_map *nfp_map, void *value)
 270{
 271        u32 *word = value;
 272        unsigned int i;
 273
 274        for (i = 0; i < DIV_ROUND_UP(nfp_map->offmap->map.value_size, 4); i++)
 275                if (nfp_map->use_map[i].type == NFP_MAP_UNUSED &&
 276                    word[i] != (__force u32)cpu_to_be32(word[i]))
 277                        nfp_map->use_map[i].non_zero_update = 1;
 278}
 279
 280static int
 281nfp_bpf_map_lookup_entry(struct bpf_offloaded_map *offmap,
 282                         void *key, void *value)
 283{
 284        int err;
 285
 286        err = nfp_bpf_ctrl_lookup_entry(offmap, key, value);
 287        if (err)
 288                return err;
 289
 290        nfp_map_bpf_byte_swap(offmap->dev_priv, value);
 291        return 0;
 292}
 293
 294static int
 295nfp_bpf_map_update_entry(struct bpf_offloaded_map *offmap,
 296                         void *key, void *value, u64 flags)
 297{
 298        nfp_map_bpf_byte_swap(offmap->dev_priv, value);
 299        nfp_map_bpf_byte_swap_record(offmap->dev_priv, value);
 300        return nfp_bpf_ctrl_update_entry(offmap, key, value, flags);
 301}
 302
 303static int
 304nfp_bpf_map_get_next_key(struct bpf_offloaded_map *offmap,
 305                         void *key, void *next_key)
 306{
 307        if (!key)
 308                return nfp_bpf_ctrl_getfirst_entry(offmap, next_key);
 309        return nfp_bpf_ctrl_getnext_entry(offmap, key, next_key);
 310}
 311
 312static int
 313nfp_bpf_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
 314{
 315        if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
 316                return -EINVAL;
 317        return nfp_bpf_ctrl_del_entry(offmap, key);
 318}
 319
 320static const struct bpf_map_dev_ops nfp_bpf_map_ops = {
 321        .map_get_next_key       = nfp_bpf_map_get_next_key,
 322        .map_lookup_elem        = nfp_bpf_map_lookup_entry,
 323        .map_update_elem        = nfp_bpf_map_update_entry,
 324        .map_delete_elem        = nfp_bpf_map_delete_elem,
 325};
 326
 327static int
 328nfp_bpf_map_alloc(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
 329{
 330        struct nfp_bpf_map *nfp_map;
 331        unsigned int use_map_size;
 332        long long int res;
 333
 334        if (!bpf->maps.types)
 335                return -EOPNOTSUPP;
 336
 337        if (offmap->map.map_flags ||
 338            offmap->map.numa_node != NUMA_NO_NODE) {
 339                pr_info("map flags are not supported\n");
 340                return -EINVAL;
 341        }
 342
 343        if (!(bpf->maps.types & 1 << offmap->map.map_type)) {
 344                pr_info("map type not supported\n");
 345                return -EOPNOTSUPP;
 346        }
 347        if (bpf->maps.max_maps == bpf->maps_in_use) {
 348                pr_info("too many maps for a device\n");
 349                return -ENOMEM;
 350        }
 351        if (bpf->maps.max_elems - bpf->map_elems_in_use <
 352            offmap->map.max_entries) {
 353                pr_info("map with too many elements: %u, left: %u\n",
 354                        offmap->map.max_entries,
 355                        bpf->maps.max_elems - bpf->map_elems_in_use);
 356                return -ENOMEM;
 357        }
 358
 359        if (round_up(offmap->map.key_size, 8) +
 360            round_up(offmap->map.value_size, 8) > bpf->maps.max_elem_sz) {
 361                pr_info("map elements too large: %u, FW max element size (key+value): %u\n",
 362                        round_up(offmap->map.key_size, 8) +
 363                        round_up(offmap->map.value_size, 8),
 364                        bpf->maps.max_elem_sz);
 365                return -ENOMEM;
 366        }
 367        if (offmap->map.key_size > bpf->maps.max_key_sz) {
 368                pr_info("map key size %u, FW max is %u\n",
 369                        offmap->map.key_size, bpf->maps.max_key_sz);
 370                return -ENOMEM;
 371        }
 372        if (offmap->map.value_size > bpf->maps.max_val_sz) {
 373                pr_info("map value size %u, FW max is %u\n",
 374                        offmap->map.value_size, bpf->maps.max_val_sz);
 375                return -ENOMEM;
 376        }
 377
 378        use_map_size = DIV_ROUND_UP(offmap->map.value_size, 4) *
 379                       FIELD_SIZEOF(struct nfp_bpf_map, use_map[0]);
 380
 381        nfp_map = kzalloc(sizeof(*nfp_map) + use_map_size, GFP_USER);
 382        if (!nfp_map)
 383                return -ENOMEM;
 384
 385        offmap->dev_priv = nfp_map;
 386        nfp_map->offmap = offmap;
 387        nfp_map->bpf = bpf;
 388
 389        res = nfp_bpf_ctrl_alloc_map(bpf, &offmap->map);
 390        if (res < 0) {
 391                kfree(nfp_map);
 392                return res;
 393        }
 394
 395        nfp_map->tid = res;
 396        offmap->dev_ops = &nfp_bpf_map_ops;
 397        bpf->maps_in_use++;
 398        bpf->map_elems_in_use += offmap->map.max_entries;
 399        list_add_tail(&nfp_map->l, &bpf->map_list);
 400
 401        return 0;
 402}
 403
 404static int
 405nfp_bpf_map_free(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
 406{
 407        struct nfp_bpf_map *nfp_map = offmap->dev_priv;
 408
 409        nfp_bpf_ctrl_free_map(bpf, nfp_map);
 410        list_del_init(&nfp_map->l);
 411        bpf->map_elems_in_use -= offmap->map.max_entries;
 412        bpf->maps_in_use--;
 413        kfree(nfp_map);
 414
 415        return 0;
 416}
 417
 418int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn, struct netdev_bpf *bpf)
 419{
 420        switch (bpf->command) {
 421        case BPF_OFFLOAD_MAP_ALLOC:
 422                return nfp_bpf_map_alloc(app->priv, bpf->offmap);
 423        case BPF_OFFLOAD_MAP_FREE:
 424                return nfp_bpf_map_free(app->priv, bpf->offmap);
 425        default:
 426                return -EINVAL;
 427        }
 428}
 429
 430static unsigned long
 431nfp_bpf_perf_event_copy(void *dst, const void *src,
 432                        unsigned long off, unsigned long len)
 433{
 434        memcpy(dst, src + off, len);
 435        return 0;
 436}
 437
 438int nfp_bpf_event_output(struct nfp_app_bpf *bpf, const void *data,
 439                         unsigned int len)
 440{
 441        struct cmsg_bpf_event *cbe = (void *)data;
 442        struct nfp_bpf_neutral_map *record;
 443        u32 pkt_size, data_size, map_id;
 444        u64 map_id_full;
 445
 446        if (len < sizeof(struct cmsg_bpf_event))
 447                return -EINVAL;
 448
 449        pkt_size = be32_to_cpu(cbe->pkt_size);
 450        data_size = be32_to_cpu(cbe->data_size);
 451        map_id_full = be64_to_cpu(cbe->map_ptr);
 452        map_id = map_id_full;
 453
 454        if (len < sizeof(struct cmsg_bpf_event) + pkt_size + data_size)
 455                return -EINVAL;
 456        if (cbe->hdr.ver != NFP_CCM_ABI_VERSION)
 457                return -EINVAL;
 458
 459        rcu_read_lock();
 460        record = rhashtable_lookup_fast(&bpf->maps_neutral, &map_id,
 461                                        nfp_bpf_maps_neutral_params);
 462        if (!record || map_id_full > U32_MAX) {
 463                rcu_read_unlock();
 464                cmsg_warn(bpf, "perf event: map id %lld (0x%llx) not recognized, dropping event\n",
 465                          map_id_full, map_id_full);
 466                return -EINVAL;
 467        }
 468
 469        bpf_event_output(record->ptr, be32_to_cpu(cbe->cpu_id),
 470                         &cbe->data[round_up(pkt_size, 4)], data_size,
 471                         cbe->data, pkt_size, nfp_bpf_perf_event_copy);
 472        rcu_read_unlock();
 473
 474        return 0;
 475}
 476
 477static int
 478nfp_net_bpf_load(struct nfp_net *nn, struct bpf_prog *prog,
 479                 struct netlink_ext_ack *extack)
 480{
 481        struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
 482        unsigned int fw_mtu, pkt_off, max_stack, max_prog_len;
 483        dma_addr_t dma_addr;
 484        void *img;
 485        int err;
 486
 487        fw_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
 488        pkt_off = min(prog->aux->max_pkt_offset, nn->dp.netdev->mtu);
 489        if (fw_mtu < pkt_off) {
 490                NL_SET_ERR_MSG_MOD(extack, "BPF offload not supported with potential packet access beyond HW packet split boundary");
 491                return -EOPNOTSUPP;
 492        }
 493
 494        max_stack = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64;
 495        if (nfp_prog->stack_size > max_stack) {
 496                NL_SET_ERR_MSG_MOD(extack, "stack too large");
 497                return -EOPNOTSUPP;
 498        }
 499
 500        max_prog_len = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
 501        if (nfp_prog->prog_len > max_prog_len) {
 502                NL_SET_ERR_MSG_MOD(extack, "program too long");
 503                return -EOPNOTSUPP;
 504        }
 505
 506        img = nfp_bpf_relo_for_vnic(nfp_prog, nn->app_priv);
 507        if (IS_ERR(img))
 508                return PTR_ERR(img);
 509
 510        dma_addr = dma_map_single(nn->dp.dev, img,
 511                                  nfp_prog->prog_len * sizeof(u64),
 512                                  DMA_TO_DEVICE);
 513        if (dma_mapping_error(nn->dp.dev, dma_addr)) {
 514                kfree(img);
 515                return -ENOMEM;
 516        }
 517
 518        nn_writew(nn, NFP_NET_CFG_BPF_SIZE, nfp_prog->prog_len);
 519        nn_writeq(nn, NFP_NET_CFG_BPF_ADDR, dma_addr);
 520
 521        /* Load up the JITed code */
 522        err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_BPF);
 523        if (err)
 524                NL_SET_ERR_MSG_MOD(extack,
 525                                   "FW command error while loading BPF");
 526
 527        dma_unmap_single(nn->dp.dev, dma_addr, nfp_prog->prog_len * sizeof(u64),
 528                         DMA_TO_DEVICE);
 529        kfree(img);
 530
 531        return err;
 532}
 533
 534static void
 535nfp_net_bpf_start(struct nfp_net *nn, struct netlink_ext_ack *extack)
 536{
 537        int err;
 538
 539        /* Enable passing packets through BPF function */
 540        nn->dp.ctrl |= NFP_NET_CFG_CTRL_BPF;
 541        nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
 542        err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
 543        if (err)
 544                NL_SET_ERR_MSG_MOD(extack,
 545                                   "FW command error while enabling BPF");
 546}
 547
 548static int nfp_net_bpf_stop(struct nfp_net *nn)
 549{
 550        if (!(nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF))
 551                return 0;
 552
 553        nn->dp.ctrl &= ~NFP_NET_CFG_CTRL_BPF;
 554        nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
 555
 556        return nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
 557}
 558
 559int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
 560                        bool old_prog, struct netlink_ext_ack *extack)
 561{
 562        int err;
 563
 564        if (prog && !bpf_offload_dev_match(prog, nn->dp.netdev))
 565                return -EINVAL;
 566
 567        if (prog && old_prog) {
 568                u8 cap;
 569
 570                cap = nn_readb(nn, NFP_NET_CFG_BPF_CAP);
 571                if (!(cap & NFP_NET_BPF_CAP_RELO)) {
 572                        NL_SET_ERR_MSG_MOD(extack,
 573                                           "FW does not support live reload");
 574                        return -EBUSY;
 575                }
 576        }
 577
 578        /* Something else is loaded, different program type? */
 579        if (!old_prog && nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)
 580                return -EBUSY;
 581
 582        if (old_prog && !prog)
 583                return nfp_net_bpf_stop(nn);
 584
 585        err = nfp_net_bpf_load(nn, prog, extack);
 586        if (err)
 587                return err;
 588
 589        if (!old_prog)
 590                nfp_net_bpf_start(nn, extack);
 591
 592        return 0;
 593}
 594
 595const struct bpf_prog_offload_ops nfp_bpf_dev_ops = {
 596        .insn_hook      = nfp_verify_insn,
 597        .finalize       = nfp_bpf_finalize,
 598        .replace_insn   = nfp_bpf_opt_replace_insn,
 599        .remove_insns   = nfp_bpf_opt_remove_insns,
 600        .prepare        = nfp_bpf_verifier_prep,
 601        .translate      = nfp_bpf_translate,
 602        .destroy        = nfp_bpf_destroy,
 603};
 604