drivers/net/ethernet/aquantia/atlantic/aq_ring.c

   1 /*
   2  * aQuantia Corporation Network Driver
   3  * Copyright (C) 2014-2017 aQuantia Corporation. All rights reserved
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  */
   9
  10 /* File aq_ring.c: Definition of functions for Rx/Tx rings. */
  11
  12 #include "aq_ring.h"
  13 #include "aq_nic.h"
  14 #include "aq_hw.h"
  15
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18
  19 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
  20                                        struct aq_nic_s *aq_nic)
  21 {
  22         int err = 0;
  23
  24         self->buff_ring =
  25                 kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
  26
  27         if (!self->buff_ring) {
  28                 err = -ENOMEM;
  29                 goto err_exit;
  30         }
  31         self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
  32                                                 self->size * self->dx_size,
  33                                                 &self->dx_ring_pa, GFP_KERNEL);
  34         if (!self->dx_ring) {
  35                 err = -ENOMEM;
  36                 goto err_exit;
  37         }
  38
  39 err_exit:
  40         if (err < 0) {
  41                 aq_ring_free(self);
  42                 self = NULL;
  43         }
  44         return self;
  45 }
  46
  47 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
  48                                    struct aq_nic_s *aq_nic,
  49                                    unsigned int idx,
  50                                    struct aq_nic_cfg_s *aq_nic_cfg)
  51 {
  52         int err = 0;
  53
  54         self->aq_nic = aq_nic;
  55         self->idx = idx;
  56         self->size = aq_nic_cfg->txds;
  57         self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
  58
  59         self = aq_ring_alloc(self, aq_nic);
  60         if (!self) {
  61                 err = -ENOMEM;
  62                 goto err_exit;
  63         }
  64
  65 err_exit:
  66         if (err < 0) {
  67                 aq_ring_free(self);
  68                 self = NULL;
  69         }
  70         return self;
  71 }
  72
  73 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
  74                                    struct aq_nic_s *aq_nic,
  75                                    unsigned int idx,
  76                                    struct aq_nic_cfg_s *aq_nic_cfg)
  77 {
  78         int err = 0;
  79
  80         self->aq_nic = aq_nic;
  81         self->idx = idx;
  82         self->size = aq_nic_cfg->rxds;
  83         self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
  84
  85         self = aq_ring_alloc(self, aq_nic);
  86         if (!self) {
  87                 err = -ENOMEM;
  88                 goto err_exit;
  89         }
  90
  91 err_exit:
  92         if (err < 0) {
  93                 aq_ring_free(self);
  94                 self = NULL;
  95         }
  96         return self;
  97 }
  98
  99 int aq_ring_init(struct aq_ring_s *self)
 100 {
 101         self->hw_head = 0;
 102         self->sw_head = 0;
 103         self->sw_tail = 0;
 104         return 0;
 105 }
 106
 107 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
 108                                        unsigned int t)
 109 {
 110         return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
 111 }
 112
 113 void aq_ring_update_queue_state(struct aq_ring_s *ring)
 114 {
 115         if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
 116                 aq_ring_queue_stop(ring);
 117         else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
 118                 aq_ring_queue_wake(ring);
 119 }
 120
 121 void aq_ring_queue_wake(struct aq_ring_s *ring)
 122 {
 123         struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
 124
 125         if (__netif_subqueue_stopped(ndev, ring->idx)) {
 126                 netif_wake_subqueue(ndev, ring->idx);
 127                 ring->stats.tx.queue_restarts++;
 128         }
 129 }
 130
 131 void aq_ring_queue_stop(struct aq_ring_s *ring)
 132 {
 133         struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
 134
 135         if (!__netif_subqueue_stopped(ndev, ring->idx))
 136                 netif_stop_subqueue(ndev, ring->idx);
 137 }
 138
 139 bool aq_ring_tx_clean(struct aq_ring_s *self)
 140 {
 141         struct device *dev = aq_nic_get_dev(self->aq_nic);
 142         unsigned int budget;
 143
 144         for (budget = AQ_CFG_TX_CLEAN_BUDGET;
 145              budget && self->sw_head != self->hw_head; budget--) {
 146                 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
 147
 148                 if (likely(buff->is_mapped)) {
 149                         if (unlikely(buff->is_sop)) {
 150                                 if (!buff->is_eop &&
 151                                     buff->eop_index != 0xffffU &&
 152                                     (!aq_ring_dx_in_range(self->sw_head,
 153                                                 buff->eop_index,
 154                                                 self->hw_head)))
 155                                         break;
 156
 157                                 dma_unmap_single(dev, buff->pa, buff->len,
 158                                                  DMA_TO_DEVICE);
 159                         } else {
 160                                 dma_unmap_page(dev, buff->pa, buff->len,
 161                                                DMA_TO_DEVICE);
 162                         }
 163                 }
 164
 165                 if (unlikely(buff->is_eop)) {
 166                         ++self->stats.rx.packets;
 167                         self->stats.tx.bytes += buff->skb->len;
 168
 169                         dev_kfree_skb_any(buff->skb);
 170                 }
 171                 buff->pa = 0U;
 172                 buff->eop_index = 0xffffU;
 173                 self->sw_head = aq_ring_next_dx(self, self->sw_head);
 174         }
 175
 176         return !!budget;
 177 }
 178
 179 static void aq_rx_checksum(struct aq_ring_s *self,
 180                            struct aq_ring_buff_s *buff,
 181                            struct sk_buff *skb)
 182 {
 183         if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
 184                 return;
 185
 186         if (unlikely(buff->is_cso_err)) {
 187                 ++self->stats.rx.errors;
 188                 skb->ip_summed = CHECKSUM_NONE;
 189                 return;
 190         }
 191         if (buff->is_ip_cso) {
 192                 __skb_incr_checksum_unnecessary(skb);
 193         } else {
 194                 skb->ip_summed = CHECKSUM_NONE;
 195         }
 196
 197         if (buff->is_udp_cso || buff->is_tcp_cso)
 198                 __skb_incr_checksum_unnecessary(skb);
 199 }
 200
 201 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
 202 int aq_ring_rx_clean(struct aq_ring_s *self,
 203                      struct napi_struct *napi,
 204                      int *work_done,
 205                      int budget)
 206 {
 207         struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
 208         int err = 0;
 209         bool is_rsc_completed = true;
 210
 211         for (; (self->sw_head != self->hw_head) && budget;
 212                 self->sw_head = aq_ring_next_dx(self, self->sw_head),
 213                 --budget, ++(*work_done)) {
 214                 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
 215                 struct sk_buff *skb = NULL;
 216                 unsigned int next_ = 0U;
 217                 unsigned int i = 0U;
 218                 struct aq_ring_buff_s *buff_ = NULL;
 219
 220                 if (buff->is_error) {
 221                         __free_pages(buff->page, 0);
 222                         continue;
 223                 }
 224
 225                 if (buff->is_cleaned)
 226                         continue;
 227
 228                 if (!buff->is_eop) {
 229                         for (next_ = buff->next,
 230                              buff_ = &self->buff_ring[next_]; true;
 231                              next_ = buff_->next,
 232                              buff_ = &self->buff_ring[next_]) {
 233                                 is_rsc_completed =
 234                                         aq_ring_dx_in_range(self->sw_head,
 235                                                             next_,
 236                                                             self->hw_head);
 237
 238                                 if (unlikely(!is_rsc_completed)) {
 239                                         is_rsc_completed = false;
 240                                         break;
 241                                 }
 242
 243                                 if (buff_->is_eop)
 244                                         break;
 245                         }
 246
 247                         if (!is_rsc_completed) {
 248                                 err = 0;
 249                                 goto err_exit;
 250                         }
 251                 }
 252
 253                 /* for single fragment packets use build_skb() */
 254                 if (buff->is_eop &&
 255                     buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
 256                         skb = build_skb(page_address(buff->page),
 257                                         AQ_CFG_RX_FRAME_MAX);
 258                         if (unlikely(!skb)) {
 259                                 err = -ENOMEM;
 260                                 goto err_exit;
 261                         }
 262
 263                         skb_put(skb, buff->len);
 264                 } else {
 265                         skb = netdev_alloc_skb(ndev, ETH_HLEN);
 266                         if (unlikely(!skb)) {
 267                                 err = -ENOMEM;
 268                                 goto err_exit;
 269                         }
 270                         skb_put(skb, ETH_HLEN);
 271                         memcpy(skb->data, page_address(buff->page), ETH_HLEN);
 272
 273                         skb_add_rx_frag(skb, 0, buff->page, ETH_HLEN,
 274                                         buff->len - ETH_HLEN,
 275                                         SKB_TRUESIZE(buff->len - ETH_HLEN));
 276
 277                         if (!buff->is_eop) {
 278                                 for (i = 1U, next_ = buff->next,
 279                                      buff_ = &self->buff_ring[next_];
 280                                      true; next_ = buff_->next,
 281                                      buff_ = &self->buff_ring[next_], ++i) {
 282                                         skb_add_rx_frag(skb, i,
 283                                                         buff_->page, 0,
 284                                                         buff_->len,
 285                                                         SKB_TRUESIZE(buff->len -
 286                                                         ETH_HLEN));
 287                                         buff_->is_cleaned = 1;
 288
 289                                         if (buff_->is_eop)
 290                                                 break;
 291                                 }
 292                         }
 293                 }
 294
 295                 skb->protocol = eth_type_trans(skb, ndev);
 296
 297                 aq_rx_checksum(self, buff, skb);
 298
 299                 skb_set_hash(skb, buff->rss_hash,
 300                              buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
 301                              PKT_HASH_TYPE_NONE);
 302
 303                 skb_record_rx_queue(skb, self->idx);
 304
 305                 ++self->stats.rx.packets;
 306                 self->stats.rx.bytes += skb->len;
 307
 308                 napi_gro_receive(napi, skb);
 309         }
 310
 311 err_exit:
 312         return err;
 313 }
 314
 315 int aq_ring_rx_fill(struct aq_ring_s *self)
 316 {
 317         unsigned int pages_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
 318                 (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
 319         struct aq_ring_buff_s *buff = NULL;
 320         int err = 0;
 321         int i = 0;
 322
 323         for (i = aq_ring_avail_dx(self); i--;
 324                 self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
 325                 buff = &self->buff_ring[self->sw_tail];
 326
 327                 buff->flags = 0U;
 328                 buff->len = AQ_CFG_RX_FRAME_MAX;
 329
 330                 buff->page = alloc_pages(GFP_ATOMIC | __GFP_COMP, pages_order);
 331                 if (!buff->page) {
 332                         err = -ENOMEM;
 333                         goto err_exit;
 334                 }
 335
 336                 buff->pa = dma_map_page(aq_nic_get_dev(self->aq_nic),
 337                                         buff->page, 0,
 338                                         AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
 339
 340                 if (dma_mapping_error(aq_nic_get_dev(self->aq_nic), buff->pa)) {
 341                         err = -ENOMEM;
 342                         goto err_exit;
 343                 }
 344
 345                 buff = NULL;
 346         }
 347
 348 err_exit:
 349         if (err < 0) {
 350                 if (buff && buff->page)
 351                         __free_pages(buff->page, 0);
 352         }
 353
 354         return err;
 355 }
 356
 357 void aq_ring_rx_deinit(struct aq_ring_s *self)
 358 {
 359         if (!self)
 360                 goto err_exit;
 361
 362         for (; self->sw_head != self->sw_tail;
 363                 self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
 364                 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
 365
 366                 dma_unmap_page(aq_nic_get_dev(self->aq_nic), buff->pa,
 367                                AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
 368
 369                 __free_pages(buff->page, 0);
 370         }
 371
 372 err_exit:;
 373 }
 374
 375 void aq_ring_free(struct aq_ring_s *self)
 376 {
 377         if (!self)
 378                 goto err_exit;
 379
 380         kfree(self->buff_ring);
 381
 382         if (self->dx_ring)
 383                 dma_free_coherent(aq_nic_get_dev(self->aq_nic),
 384                                   self->size * self->dx_size, self->dx_ring,
 385                                   self->dx_ring_pa);
 386
 387 err_exit:;
 388 }