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 #include "aq_hw_utils.h"
  16
  17 #include <linux/netdevice.h>
  18 #include <linux/etherdevice.h>
  19
  20 static inline void aq_free_rxpage(struct aq_rxpage *rxpage, struct device *dev)
  21 {
  22         unsigned int len = PAGE_SIZE << rxpage->order;
  23
  24         dma_unmap_page(dev, rxpage->daddr, len, DMA_FROM_DEVICE);
  25
  26         /* Drop the ref for being in the ring. */
  27         __free_pages(rxpage->page, rxpage->order);
  28         rxpage->page = NULL;
  29 }
  30
  31 static int aq_get_rxpage(struct aq_rxpage *rxpage, unsigned int order,
  32                          struct device *dev)
  33 {
  34         struct page *page;
  35         dma_addr_t daddr;
  36         int ret = -ENOMEM;
  37
  38         page = dev_alloc_pages(order);
  39         if (unlikely(!page))
  40                 goto err_exit;
  41
  42         daddr = dma_map_page(dev, page, 0, PAGE_SIZE << order,
  43                              DMA_FROM_DEVICE);
  44
  45         if (unlikely(dma_mapping_error(dev, daddr)))
  46                 goto free_page;
  47
  48         rxpage->page = page;
  49         rxpage->daddr = daddr;
  50         rxpage->order = order;
  51         rxpage->pg_off = 0;
  52
  53         return 0;
  54
  55 free_page:
  56         __free_pages(page, order);
  57
  58 err_exit:
  59         return ret;
  60 }
  61
  62 static int aq_get_rxpages(struct aq_ring_s *self, struct aq_ring_buff_s *rxbuf,
  63                           int order)
  64 {
  65         int ret;
  66
  67         if (rxbuf->rxdata.page) {
  68                 /* One means ring is the only user and can reuse */
  69                 if (page_ref_count(rxbuf->rxdata.page) > 1) {
  70                         /* Try reuse buffer */
  71                         rxbuf->rxdata.pg_off += AQ_CFG_RX_FRAME_MAX;
  72                         if (rxbuf->rxdata.pg_off + AQ_CFG_RX_FRAME_MAX <=
  73                                 (PAGE_SIZE << order)) {
  74                                 self->stats.rx.pg_flips++;
  75                         } else {
  76                                 /* Buffer exhausted. We have other users and
  77                                  * should release this page and realloc
  78                                  */
  79                                 aq_free_rxpage(&rxbuf->rxdata,
  80                                                aq_nic_get_dev(self->aq_nic));
  81                                 self->stats.rx.pg_losts++;
  82                         }
  83                 } else {
  84                         rxbuf->rxdata.pg_off = 0;
  85                         self->stats.rx.pg_reuses++;
  86                 }
  87         }
  88
  89         if (!rxbuf->rxdata.page) {
  90                 ret = aq_get_rxpage(&rxbuf->rxdata, order,
  91                                     aq_nic_get_dev(self->aq_nic));
  92                 return ret;
  93         }
  94
  95         return 0;
  96 }
  97
  98 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
  99                                        struct aq_nic_s *aq_nic)
 100 {
 101         int err = 0;
 102
 103         self->buff_ring =
 104                 kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
 105
 106         if (!self->buff_ring) {
 107                 err = -ENOMEM;
 108                 goto err_exit;
 109         }
 110         self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
 111                                            self->size * self->dx_size,
 112                                            &self->dx_ring_pa, GFP_KERNEL);
 113         if (!self->dx_ring) {
 114                 err = -ENOMEM;
 115                 goto err_exit;
 116         }
 117
 118 err_exit:
 119         if (err < 0) {
 120                 aq_ring_free(self);
 121                 self = NULL;
 122         }
 123         return self;
 124 }
 125
 126 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
 127                                    struct aq_nic_s *aq_nic,
 128                                    unsigned int idx,
 129                                    struct aq_nic_cfg_s *aq_nic_cfg)
 130 {
 131         int err = 0;
 132
 133         self->aq_nic = aq_nic;
 134         self->idx = idx;
 135         self->size = aq_nic_cfg->txds;
 136         self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
 137
 138         self = aq_ring_alloc(self, aq_nic);
 139         if (!self) {
 140                 err = -ENOMEM;
 141                 goto err_exit;
 142         }
 143
 144 err_exit:
 145         if (err < 0) {
 146                 aq_ring_free(self);
 147                 self = NULL;
 148         }
 149         return self;
 150 }
 151
 152 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
 153                                    struct aq_nic_s *aq_nic,
 154                                    unsigned int idx,
 155                                    struct aq_nic_cfg_s *aq_nic_cfg)
 156 {
 157         int err = 0;
 158
 159         self->aq_nic = aq_nic;
 160         self->idx = idx;
 161         self->size = aq_nic_cfg->rxds;
 162         self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
 163         self->page_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
 164                                (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
 165
 166         if (aq_nic_cfg->rxpageorder > self->page_order)
 167                 self->page_order = aq_nic_cfg->rxpageorder;
 168
 169         self = aq_ring_alloc(self, aq_nic);
 170         if (!self) {
 171                 err = -ENOMEM;
 172                 goto err_exit;
 173         }
 174
 175 err_exit:
 176         if (err < 0) {
 177                 aq_ring_free(self);
 178                 self = NULL;
 179         }
 180         return self;
 181 }
 182
 183 int aq_ring_init(struct aq_ring_s *self)
 184 {
 185         self->hw_head = 0;
 186         self->sw_head = 0;
 187         self->sw_tail = 0;
 188         return 0;
 189 }
 190
 191 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
 192                                        unsigned int t)
 193 {
 194         return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
 195 }
 196
 197 void aq_ring_update_queue_state(struct aq_ring_s *ring)
 198 {
 199         if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
 200                 aq_ring_queue_stop(ring);
 201         else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
 202                 aq_ring_queue_wake(ring);
 203 }
 204
 205 void aq_ring_queue_wake(struct aq_ring_s *ring)
 206 {
 207         struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
 208
 209         if (__netif_subqueue_stopped(ndev, ring->idx)) {
 210                 netif_wake_subqueue(ndev, ring->idx);
 211                 ring->stats.tx.queue_restarts++;
 212         }
 213 }
 214
 215 void aq_ring_queue_stop(struct aq_ring_s *ring)
 216 {
 217         struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
 218
 219         if (!__netif_subqueue_stopped(ndev, ring->idx))
 220                 netif_stop_subqueue(ndev, ring->idx);
 221 }
 222
 223 bool aq_ring_tx_clean(struct aq_ring_s *self)
 224 {
 225         struct device *dev = aq_nic_get_dev(self->aq_nic);
 226         unsigned int budget;
 227
 228         for (budget = AQ_CFG_TX_CLEAN_BUDGET;
 229              budget && self->sw_head != self->hw_head; budget--) {
 230                 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
 231
 232                 if (likely(buff->is_mapped)) {
 233                         if (unlikely(buff->is_sop)) {
 234                                 if (!buff->is_eop &&
 235                                     buff->eop_index != 0xffffU &&
 236                                     (!aq_ring_dx_in_range(self->sw_head,
 237                                                 buff->eop_index,
 238                                                 self->hw_head)))
 239                                         break;
 240
 241                                 dma_unmap_single(dev, buff->pa, buff->len,
 242                                                  DMA_TO_DEVICE);
 243                         } else {
 244                                 dma_unmap_page(dev, buff->pa, buff->len,
 245                                                DMA_TO_DEVICE);
 246                         }
 247                 }
 248
 249                 if (unlikely(buff->is_eop))
 250                         dev_kfree_skb_any(buff->skb);
 251
 252                 buff->pa = 0U;
 253                 buff->eop_index = 0xffffU;
 254                 self->sw_head = aq_ring_next_dx(self, self->sw_head);
 255         }
 256
 257         return !!budget;
 258 }
 259
 260 static void aq_rx_checksum(struct aq_ring_s *self,
 261                            struct aq_ring_buff_s *buff,
 262                            struct sk_buff *skb)
 263 {
 264         if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
 265                 return;
 266
 267         if (unlikely(buff->is_cso_err)) {
 268                 ++self->stats.rx.errors;
 269                 skb->ip_summed = CHECKSUM_NONE;
 270                 return;
 271         }
 272         if (buff->is_ip_cso) {
 273                 __skb_incr_checksum_unnecessary(skb);
 274         } else {
 275                 skb->ip_summed = CHECKSUM_NONE;
 276         }
 277
 278         if (buff->is_udp_cso || buff->is_tcp_cso)
 279                 __skb_incr_checksum_unnecessary(skb);
 280 }
 281
 282 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
 283 int aq_ring_rx_clean(struct aq_ring_s *self,
 284                      struct napi_struct *napi,
 285                      int *work_done,
 286                      int budget)
 287 {
 288         struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
 289         bool is_rsc_completed = true;
 290         int err = 0;
 291
 292         for (; (self->sw_head != self->hw_head) && budget;
 293                 self->sw_head = aq_ring_next_dx(self, self->sw_head),
 294                 --budget, ++(*work_done)) {
 295                 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
 296                 struct aq_ring_buff_s *buff_ = NULL;
 297                 struct sk_buff *skb = NULL;
 298                 unsigned int next_ = 0U;
 299                 unsigned int i = 0U;
 300                 u16 hdr_len;
 301
 302                 if (buff->is_cleaned)
 303                         continue;
 304
 305                 if (!buff->is_eop) {
 306                         buff_ = buff;
 307                         do {
 308                                 next_ = buff_->next,
 309                                 buff_ = &self->buff_ring[next_];
 310                                 is_rsc_completed =
 311                                         aq_ring_dx_in_range(self->sw_head,
 312                                                             next_,
 313                                                             self->hw_head);
 314
 315                                 if (unlikely(!is_rsc_completed))
 316                                         break;
 317
 318                                 buff->is_error |= buff_->is_error;
 319
 320                         } while (!buff_->is_eop);
 321
 322                         if (!is_rsc_completed) {
 323                                 err = 0;
 324                                 goto err_exit;
 325                         }
 326                         if (buff->is_error) {
 327                                 buff_ = buff;
 328                                 do {
 329                                         next_ = buff_->next,
 330                                         buff_ = &self->buff_ring[next_];
 331
 332                                         buff_->is_cleaned = true;
 333                                 } while (!buff_->is_eop);
 334
 335                                 ++self->stats.rx.errors;
 336                                 continue;
 337                         }
 338                 }
 339
 340                 if (buff->is_error) {
 341                         ++self->stats.rx.errors;
 342                         continue;
 343                 }
 344
 345                 dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
 346                                               buff->rxdata.daddr,
 347                                               buff->rxdata.pg_off,
 348                                               buff->len, DMA_FROM_DEVICE);
 349
 350                 /* for single fragment packets use build_skb() */
 351                 if (buff->is_eop &&
 352                     buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
 353                         skb = build_skb(aq_buf_vaddr(&buff->rxdata),
 354                                         AQ_CFG_RX_FRAME_MAX);
 355                         if (unlikely(!skb)) {
 356                                 err = -ENOMEM;
 357                                 goto err_exit;
 358                         }
 359                         skb_put(skb, buff->len);
 360                         page_ref_inc(buff->rxdata.page);
 361                 } else {
 362                         skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
 363                         if (unlikely(!skb)) {
 364                                 err = -ENOMEM;
 365                                 goto err_exit;
 366                         }
 367
 368                         hdr_len = buff->len;
 369                         if (hdr_len > AQ_CFG_RX_HDR_SIZE)
 370                                 hdr_len = eth_get_headlen(skb->dev,
 371                                                           aq_buf_vaddr(&buff->rxdata),
 372                                                           AQ_CFG_RX_HDR_SIZE);
 373
 374                         memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
 375                                ALIGN(hdr_len, sizeof(long)));
 376
 377                         if (buff->len - hdr_len > 0) {
 378                                 skb_add_rx_frag(skb, 0, buff->rxdata.page,
 379                                                 buff->rxdata.pg_off + hdr_len,
 380                                                 buff->len - hdr_len,
 381                                                 AQ_CFG_RX_FRAME_MAX);
 382                                 page_ref_inc(buff->rxdata.page);
 383                         }
 384
 385                         if (!buff->is_eop) {
 386                                 buff_ = buff;
 387                                 i = 1U;
 388                                 do {
 389                                         next_ = buff_->next,
 390                                         buff_ = &self->buff_ring[next_];
 391
 392                                         dma_sync_single_range_for_cpu(
 393                                                         aq_nic_get_dev(self->aq_nic),
 394                                                         buff_->rxdata.daddr,
 395                                                         buff_->rxdata.pg_off,
 396                                                         buff_->len,
 397                                                         DMA_FROM_DEVICE);
 398                                         skb_add_rx_frag(skb, i++,
 399                                                         buff_->rxdata.page,
 400                                                         buff_->rxdata.pg_off,
 401                                                         buff_->len,
 402                                                         AQ_CFG_RX_FRAME_MAX);
 403                                         page_ref_inc(buff_->rxdata.page);
 404                                         buff_->is_cleaned = 1;
 405
 406                                         buff->is_ip_cso &= buff_->is_ip_cso;
 407                                         buff->is_udp_cso &= buff_->is_udp_cso;
 408                                         buff->is_tcp_cso &= buff_->is_tcp_cso;
 409                                         buff->is_cso_err |= buff_->is_cso_err;
 410
 411                                 } while (!buff_->is_eop);
 412                         }
 413                 }
 414
 415                 skb->protocol = eth_type_trans(skb, ndev);
 416
 417                 aq_rx_checksum(self, buff, skb);
 418
 419                 skb_set_hash(skb, buff->rss_hash,
 420                              buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
 421                              PKT_HASH_TYPE_NONE);
 422
 423                 skb_record_rx_queue(skb, self->idx);
 424
 425                 ++self->stats.rx.packets;
 426                 self->stats.rx.bytes += skb->len;
 427
 428                 napi_gro_receive(napi, skb);
 429         }
 430
 431 err_exit:
 432         return err;
 433 }
 434
 435 int aq_ring_rx_fill(struct aq_ring_s *self)
 436 {
 437         unsigned int page_order = self->page_order;
 438         struct aq_ring_buff_s *buff = NULL;
 439         int err = 0;
 440         int i = 0;
 441
 442         if (aq_ring_avail_dx(self) < min_t(unsigned int, AQ_CFG_RX_REFILL_THRES,
 443                                            self->size / 2))
 444                 return err;
 445
 446         for (i = aq_ring_avail_dx(self); i--;
 447                 self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
 448                 buff = &self->buff_ring[self->sw_tail];
 449
 450                 buff->flags = 0U;
 451                 buff->len = AQ_CFG_RX_FRAME_MAX;
 452
 453                 err = aq_get_rxpages(self, buff, page_order);
 454                 if (err)
 455                         goto err_exit;
 456
 457                 buff->pa = aq_buf_daddr(&buff->rxdata);
 458                 buff = NULL;
 459         }
 460
 461 err_exit:
 462         return err;
 463 }
 464
 465 void aq_ring_rx_deinit(struct aq_ring_s *self)
 466 {
 467         if (!self)
 468                 goto err_exit;
 469
 470         for (; self->sw_head != self->sw_tail;
 471                 self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
 472                 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
 473
 474                 aq_free_rxpage(&buff->rxdata, aq_nic_get_dev(self->aq_nic));
 475         }
 476
 477 err_exit:;
 478 }
 479
 480 void aq_ring_free(struct aq_ring_s *self)
 481 {
 482         if (!self)
 483                 goto err_exit;
 484
 485         kfree(self->buff_ring);
 486
 487         if (self->dx_ring)
 488                 dma_free_coherent(aq_nic_get_dev(self->aq_nic),
 489                                   self->size * self->dx_size, self->dx_ring,
 490                                   self->dx_ring_pa);
 491
 492 err_exit:;
 493 }