root/drivers/net/ethernet/sfc/falcon/nic.c

DEFINITIONS

1. ef4_nic_alloc_buffer
2. ef4_nic_free_buffer
3. ef4_nic_event_present
4. ef4_nic_event_test_start
5. ef4_nic_irq_test_start
6. ef4_nic_init_interrupt
7. ef4_nic_fini_interrupt
8. ef4_nic_get_regs_len
9. ef4_nic_get_regs
10. ef4_nic_describe_stats
11. ef4_nic_update_stats
12. ef4_nic_fix_nodesc_drop_stat

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /****************************************************************************
   3  * Driver for Solarflare network controllers and boards
   4  * Copyright 2005-2006 Fen Systems Ltd.
   5  * Copyright 2006-2013 Solarflare Communications Inc.
   6  */
   7 
   8 #include <linux/bitops.h>
   9 #include <linux/delay.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/pci.h>
  12 #include <linux/module.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/cpu_rmap.h>
  15 #include "net_driver.h"
  16 #include "bitfield.h"
  17 #include "efx.h"
  18 #include "nic.h"
  19 #include "farch_regs.h"
  20 #include "io.h"
  21 #include "workarounds.h"
  22 
  23 /**************************************************************************
  24  *
  25  * Generic buffer handling
  26  * These buffers are used for interrupt status, MAC stats, etc.
  27  *
  28  **************************************************************************/
  29 
  30 int ef4_nic_alloc_buffer(struct ef4_nic *efx, struct ef4_buffer *buffer,
  31                          unsigned int len, gfp_t gfp_flags)
  32 {
  33         buffer->addr = dma_alloc_coherent(&efx->pci_dev->dev, len,
  34                                           &buffer->dma_addr, gfp_flags);
  35         if (!buffer->addr)
  36                 return -ENOMEM;
  37         buffer->len = len;
  38         return 0;
  39 }
  40 
  41 void ef4_nic_free_buffer(struct ef4_nic *efx, struct ef4_buffer *buffer)
  42 {
  43         if (buffer->addr) {
  44                 dma_free_coherent(&efx->pci_dev->dev, buffer->len,
  45                                   buffer->addr, buffer->dma_addr);
  46                 buffer->addr = NULL;
  47         }
  48 }
  49 
  50 /* Check whether an event is present in the eventq at the current
  51  * read pointer.  Only useful for self-test.
  52  */
  53 bool ef4_nic_event_present(struct ef4_channel *channel)
  54 {
  55         return ef4_event_present(ef4_event(channel, channel->eventq_read_ptr));
  56 }
  57 
  58 void ef4_nic_event_test_start(struct ef4_channel *channel)
  59 {
  60         channel->event_test_cpu = -1;
  61         smp_wmb();
  62         channel->efx->type->ev_test_generate(channel);
  63 }
  64 
  65 int ef4_nic_irq_test_start(struct ef4_nic *efx)
  66 {
  67         efx->last_irq_cpu = -1;
  68         smp_wmb();
  69         return efx->type->irq_test_generate(efx);
  70 }
  71 
  72 /* Hook interrupt handler(s)
  73  * Try MSI and then legacy interrupts.
  74  */
  75 int ef4_nic_init_interrupt(struct ef4_nic *efx)
  76 {
  77         struct ef4_channel *channel;
  78         unsigned int n_irqs;
  79         int rc;
  80 
  81         if (!EF4_INT_MODE_USE_MSI(efx)) {
  82                 rc = request_irq(efx->legacy_irq,
  83                                  efx->type->irq_handle_legacy, IRQF_SHARED,
  84                                  efx->name, efx);
  85                 if (rc) {
  86                         netif_err(efx, drv, efx->net_dev,
  87                                   "failed to hook legacy IRQ %d\n",
  88                                   efx->pci_dev->irq);
  89                         goto fail1;
  90                 }
  91                 return 0;
  92         }
  93 
  94 #ifdef CONFIG_RFS_ACCEL
  95         if (efx->interrupt_mode == EF4_INT_MODE_MSIX) {
  96                 efx->net_dev->rx_cpu_rmap =
  97                         alloc_irq_cpu_rmap(efx->n_rx_channels);
  98                 if (!efx->net_dev->rx_cpu_rmap) {
  99                         rc = -ENOMEM;
 100                         goto fail1;
 101                 }
 102         }
 103 #endif
 104 
 105         /* Hook MSI or MSI-X interrupt */
 106         n_irqs = 0;
 107         ef4_for_each_channel(channel, efx) {
 108                 rc = request_irq(channel->irq, efx->type->irq_handle_msi,
 109                                  IRQF_PROBE_SHARED, /* Not shared */
 110                                  efx->msi_context[channel->channel].name,
 111                                  &efx->msi_context[channel->channel]);
 112                 if (rc) {
 113                         netif_err(efx, drv, efx->net_dev,
 114                                   "failed to hook IRQ %d\n", channel->irq);
 115                         goto fail2;
 116                 }
 117                 ++n_irqs;
 118 
 119 #ifdef CONFIG_RFS_ACCEL
 120                 if (efx->interrupt_mode == EF4_INT_MODE_MSIX &&
 121                     channel->channel < efx->n_rx_channels) {
 122                         rc = irq_cpu_rmap_add(efx->net_dev->rx_cpu_rmap,
 123                                               channel->irq);
 124                         if (rc)
 125                                 goto fail2;
 126                 }
 127 #endif
 128         }
 129 
 130         return 0;
 131 
 132  fail2:
 133 #ifdef CONFIG_RFS_ACCEL
 134         free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
 135         efx->net_dev->rx_cpu_rmap = NULL;
 136 #endif
 137         ef4_for_each_channel(channel, efx) {
 138                 if (n_irqs-- == 0)
 139                         break;
 140                 free_irq(channel->irq, &efx->msi_context[channel->channel]);
 141         }
 142  fail1:
 143         return rc;
 144 }
 145 
 146 void ef4_nic_fini_interrupt(struct ef4_nic *efx)
 147 {
 148         struct ef4_channel *channel;
 149 
 150 #ifdef CONFIG_RFS_ACCEL
 151         free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
 152         efx->net_dev->rx_cpu_rmap = NULL;
 153 #endif
 154 
 155         if (EF4_INT_MODE_USE_MSI(efx)) {
 156                 /* Disable MSI/MSI-X interrupts */
 157                 ef4_for_each_channel(channel, efx)
 158                         free_irq(channel->irq,
 159                                  &efx->msi_context[channel->channel]);
 160         } else {
 161                 /* Disable legacy interrupt */
 162                 free_irq(efx->legacy_irq, efx);
 163         }
 164 }
 165 
 166 /* Register dump */
 167 
 168 #define REGISTER_REVISION_FA    1
 169 #define REGISTER_REVISION_FB    2
 170 #define REGISTER_REVISION_FC    3
 171 #define REGISTER_REVISION_FZ    3       /* last Falcon arch revision */
 172 #define REGISTER_REVISION_ED    4
 173 #define REGISTER_REVISION_EZ    4       /* latest EF10 revision */
 174 
 175 struct ef4_nic_reg {
 176         u32 offset:24;
 177         u32 min_revision:3, max_revision:3;
 178 };
 179 
 180 #define REGISTER(name, arch, min_rev, max_rev) {                        \
 181         arch ## R_ ## min_rev ## max_rev ## _ ## name,                  \
 182         REGISTER_REVISION_ ## arch ## min_rev,                          \
 183         REGISTER_REVISION_ ## arch ## max_rev                           \
 184 }
 185 #define REGISTER_AA(name) REGISTER(name, F, A, A)
 186 #define REGISTER_AB(name) REGISTER(name, F, A, B)
 187 #define REGISTER_AZ(name) REGISTER(name, F, A, Z)
 188 #define REGISTER_BB(name) REGISTER(name, F, B, B)
 189 #define REGISTER_BZ(name) REGISTER(name, F, B, Z)
 190 #define REGISTER_CZ(name) REGISTER(name, F, C, Z)
 191 
 192 static const struct ef4_nic_reg ef4_nic_regs[] = {
 193         REGISTER_AZ(ADR_REGION),
 194         REGISTER_AZ(INT_EN_KER),
 195         REGISTER_BZ(INT_EN_CHAR),
 196         REGISTER_AZ(INT_ADR_KER),
 197         REGISTER_BZ(INT_ADR_CHAR),
 198         /* INT_ACK_KER is WO */
 199         /* INT_ISR0 is RC */
 200         REGISTER_AZ(HW_INIT),
 201         REGISTER_CZ(USR_EV_CFG),
 202         REGISTER_AB(EE_SPI_HCMD),
 203         REGISTER_AB(EE_SPI_HADR),
 204         REGISTER_AB(EE_SPI_HDATA),
 205         REGISTER_AB(EE_BASE_PAGE),
 206         REGISTER_AB(EE_VPD_CFG0),
 207         /* EE_VPD_SW_CNTL and EE_VPD_SW_DATA are not used */
 208         /* PMBX_DBG_IADDR and PBMX_DBG_IDATA are indirect */
 209         /* PCIE_CORE_INDIRECT is indirect */
 210         REGISTER_AB(NIC_STAT),
 211         REGISTER_AB(GPIO_CTL),
 212         REGISTER_AB(GLB_CTL),
 213         /* FATAL_INTR_KER and FATAL_INTR_CHAR are partly RC */
 214         REGISTER_BZ(DP_CTRL),
 215         REGISTER_AZ(MEM_STAT),
 216         REGISTER_AZ(CS_DEBUG),
 217         REGISTER_AZ(ALTERA_BUILD),
 218         REGISTER_AZ(CSR_SPARE),
 219         REGISTER_AB(PCIE_SD_CTL0123),
 220         REGISTER_AB(PCIE_SD_CTL45),
 221         REGISTER_AB(PCIE_PCS_CTL_STAT),
 222         /* DEBUG_DATA_OUT is not used */
 223         /* DRV_EV is WO */
 224         REGISTER_AZ(EVQ_CTL),
 225         REGISTER_AZ(EVQ_CNT1),
 226         REGISTER_AZ(EVQ_CNT2),
 227         REGISTER_AZ(BUF_TBL_CFG),
 228         REGISTER_AZ(SRM_RX_DC_CFG),
 229         REGISTER_AZ(SRM_TX_DC_CFG),
 230         REGISTER_AZ(SRM_CFG),
 231         /* BUF_TBL_UPD is WO */
 232         REGISTER_AZ(SRM_UPD_EVQ),
 233         REGISTER_AZ(SRAM_PARITY),
 234         REGISTER_AZ(RX_CFG),
 235         REGISTER_BZ(RX_FILTER_CTL),
 236         /* RX_FLUSH_DESCQ is WO */
 237         REGISTER_AZ(RX_DC_CFG),
 238         REGISTER_AZ(RX_DC_PF_WM),
 239         REGISTER_BZ(RX_RSS_TKEY),
 240         /* RX_NODESC_DROP is RC */
 241         REGISTER_AA(RX_SELF_RST),
 242         /* RX_DEBUG, RX_PUSH_DROP are not used */
 243         REGISTER_CZ(RX_RSS_IPV6_REG1),
 244         REGISTER_CZ(RX_RSS_IPV6_REG2),
 245         REGISTER_CZ(RX_RSS_IPV6_REG3),
 246         /* TX_FLUSH_DESCQ is WO */
 247         REGISTER_AZ(TX_DC_CFG),
 248         REGISTER_AA(TX_CHKSM_CFG),
 249         REGISTER_AZ(TX_CFG),
 250         /* TX_PUSH_DROP is not used */
 251         REGISTER_AZ(TX_RESERVED),
 252         REGISTER_BZ(TX_PACE),
 253         /* TX_PACE_DROP_QID is RC */
 254         REGISTER_BB(TX_VLAN),
 255         REGISTER_BZ(TX_IPFIL_PORTEN),
 256         REGISTER_AB(MD_TXD),
 257         REGISTER_AB(MD_RXD),
 258         REGISTER_AB(MD_CS),
 259         REGISTER_AB(MD_PHY_ADR),
 260         REGISTER_AB(MD_ID),
 261         /* MD_STAT is RC */
 262         REGISTER_AB(MAC_STAT_DMA),
 263         REGISTER_AB(MAC_CTRL),
 264         REGISTER_BB(GEN_MODE),
 265         REGISTER_AB(MAC_MC_HASH_REG0),
 266         REGISTER_AB(MAC_MC_HASH_REG1),
 267         REGISTER_AB(GM_CFG1),
 268         REGISTER_AB(GM_CFG2),
 269         /* GM_IPG and GM_HD are not used */
 270         REGISTER_AB(GM_MAX_FLEN),
 271         /* GM_TEST is not used */
 272         REGISTER_AB(GM_ADR1),
 273         REGISTER_AB(GM_ADR2),
 274         REGISTER_AB(GMF_CFG0),
 275         REGISTER_AB(GMF_CFG1),
 276         REGISTER_AB(GMF_CFG2),
 277         REGISTER_AB(GMF_CFG3),
 278         REGISTER_AB(GMF_CFG4),
 279         REGISTER_AB(GMF_CFG5),
 280         REGISTER_BB(TX_SRC_MAC_CTL),
 281         REGISTER_AB(XM_ADR_LO),
 282         REGISTER_AB(XM_ADR_HI),
 283         REGISTER_AB(XM_GLB_CFG),
 284         REGISTER_AB(XM_TX_CFG),
 285         REGISTER_AB(XM_RX_CFG),
 286         REGISTER_AB(XM_MGT_INT_MASK),
 287         REGISTER_AB(XM_FC),
 288         REGISTER_AB(XM_PAUSE_TIME),
 289         REGISTER_AB(XM_TX_PARAM),
 290         REGISTER_AB(XM_RX_PARAM),
 291         /* XM_MGT_INT_MSK (note no 'A') is RC */
 292         REGISTER_AB(XX_PWR_RST),
 293         REGISTER_AB(XX_SD_CTL),
 294         REGISTER_AB(XX_TXDRV_CTL),
 295         /* XX_PRBS_CTL, XX_PRBS_CHK and XX_PRBS_ERR are not used */
 296         /* XX_CORE_STAT is partly RC */
 297 };
 298 
 299 struct ef4_nic_reg_table {
 300         u32 offset:24;
 301         u32 min_revision:3, max_revision:3;
 302         u32 step:6, rows:21;
 303 };
 304 
 305 #define REGISTER_TABLE_DIMENSIONS(_, offset, arch, min_rev, max_rev, step, rows) { \
 306         offset,                                                         \
 307         REGISTER_REVISION_ ## arch ## min_rev,                          \
 308         REGISTER_REVISION_ ## arch ## max_rev,                          \
 309         step, rows                                                      \
 310 }
 311 #define REGISTER_TABLE(name, arch, min_rev, max_rev)                    \
 312         REGISTER_TABLE_DIMENSIONS(                                      \
 313                 name, arch ## R_ ## min_rev ## max_rev ## _ ## name,    \
 314                 arch, min_rev, max_rev,                                 \
 315                 arch ## R_ ## min_rev ## max_rev ## _ ## name ## _STEP, \
 316                 arch ## R_ ## min_rev ## max_rev ## _ ## name ## _ROWS)
 317 #define REGISTER_TABLE_AA(name) REGISTER_TABLE(name, F, A, A)
 318 #define REGISTER_TABLE_AZ(name) REGISTER_TABLE(name, F, A, Z)
 319 #define REGISTER_TABLE_BB(name) REGISTER_TABLE(name, F, B, B)
 320 #define REGISTER_TABLE_BZ(name) REGISTER_TABLE(name, F, B, Z)
 321 #define REGISTER_TABLE_BB_CZ(name)                                      \
 322         REGISTER_TABLE_DIMENSIONS(name, FR_BZ_ ## name, F, B, B,        \
 323                                   FR_BZ_ ## name ## _STEP,              \
 324                                   FR_BB_ ## name ## _ROWS),             \
 325         REGISTER_TABLE_DIMENSIONS(name, FR_BZ_ ## name, F, C, Z,        \
 326                                   FR_BZ_ ## name ## _STEP,              \
 327                                   FR_CZ_ ## name ## _ROWS)
 328 #define REGISTER_TABLE_CZ(name) REGISTER_TABLE(name, F, C, Z)
 329 
 330 static const struct ef4_nic_reg_table ef4_nic_reg_tables[] = {
 331         /* DRIVER is not used */
 332         /* EVQ_RPTR, TIMER_COMMAND, USR_EV and {RX,TX}_DESC_UPD are WO */
 333         REGISTER_TABLE_BB(TX_IPFIL_TBL),
 334         REGISTER_TABLE_BB(TX_SRC_MAC_TBL),
 335         REGISTER_TABLE_AA(RX_DESC_PTR_TBL_KER),
 336         REGISTER_TABLE_BB_CZ(RX_DESC_PTR_TBL),
 337         REGISTER_TABLE_AA(TX_DESC_PTR_TBL_KER),
 338         REGISTER_TABLE_BB_CZ(TX_DESC_PTR_TBL),
 339         REGISTER_TABLE_AA(EVQ_PTR_TBL_KER),
 340         REGISTER_TABLE_BB_CZ(EVQ_PTR_TBL),
 341         /* We can't reasonably read all of the buffer table (up to 8MB!).
 342          * However this driver will only use a few entries.  Reading
 343          * 1K entries allows for some expansion of queue count and
 344          * size before we need to change the version. */
 345         REGISTER_TABLE_DIMENSIONS(BUF_FULL_TBL_KER, FR_AA_BUF_FULL_TBL_KER,
 346                                   F, A, A, 8, 1024),
 347         REGISTER_TABLE_DIMENSIONS(BUF_FULL_TBL, FR_BZ_BUF_FULL_TBL,
 348                                   F, B, Z, 8, 1024),
 349         REGISTER_TABLE_CZ(RX_MAC_FILTER_TBL0),
 350         REGISTER_TABLE_BB_CZ(TIMER_TBL),
 351         REGISTER_TABLE_BB_CZ(TX_PACE_TBL),
 352         REGISTER_TABLE_BZ(RX_INDIRECTION_TBL),
 353         /* TX_FILTER_TBL0 is huge and not used by this driver */
 354         REGISTER_TABLE_CZ(TX_MAC_FILTER_TBL0),
 355         REGISTER_TABLE_CZ(MC_TREG_SMEM),
 356         /* MSIX_PBA_TABLE is not mapped */
 357         /* SRM_DBG is not mapped (and is redundant with BUF_FLL_TBL) */
 358         REGISTER_TABLE_BZ(RX_FILTER_TBL0),
 359 };
 360 
 361 size_t ef4_nic_get_regs_len(struct ef4_nic *efx)
 362 {
 363         const struct ef4_nic_reg *reg;
 364         const struct ef4_nic_reg_table *table;
 365         size_t len = 0;
 366 
 367         for (reg = ef4_nic_regs;
 368              reg < ef4_nic_regs + ARRAY_SIZE(ef4_nic_regs);
 369              reg++)
 370                 if (efx->type->revision >= reg->min_revision &&
 371                     efx->type->revision <= reg->max_revision)
 372                         len += sizeof(ef4_oword_t);
 373 
 374         for (table = ef4_nic_reg_tables;
 375              table < ef4_nic_reg_tables + ARRAY_SIZE(ef4_nic_reg_tables);
 376              table++)
 377                 if (efx->type->revision >= table->min_revision &&
 378                     efx->type->revision <= table->max_revision)
 379                         len += table->rows * min_t(size_t, table->step, 16);
 380 
 381         return len;
 382 }
 383 
 384 void ef4_nic_get_regs(struct ef4_nic *efx, void *buf)
 385 {
 386         const struct ef4_nic_reg *reg;
 387         const struct ef4_nic_reg_table *table;
 388 
 389         for (reg = ef4_nic_regs;
 390              reg < ef4_nic_regs + ARRAY_SIZE(ef4_nic_regs);
 391              reg++) {
 392                 if (efx->type->revision >= reg->min_revision &&
 393                     efx->type->revision <= reg->max_revision) {
 394                         ef4_reado(efx, (ef4_oword_t *)buf, reg->offset);
 395                         buf += sizeof(ef4_oword_t);
 396                 }
 397         }
 398 
 399         for (table = ef4_nic_reg_tables;
 400              table < ef4_nic_reg_tables + ARRAY_SIZE(ef4_nic_reg_tables);
 401              table++) {
 402                 size_t size, i;
 403 
 404                 if (!(efx->type->revision >= table->min_revision &&
 405                       efx->type->revision <= table->max_revision))
 406                         continue;
 407 
 408                 size = min_t(size_t, table->step, 16);
 409 
 410                 for (i = 0; i < table->rows; i++) {
 411                         switch (table->step) {
 412                         case 4: /* 32-bit SRAM */
 413                                 ef4_readd(efx, buf, table->offset + 4 * i);
 414                                 break;
 415                         case 8: /* 64-bit SRAM */
 416                                 ef4_sram_readq(efx,
 417                                                efx->membase + table->offset,
 418                                                buf, i);
 419                                 break;
 420                         case 16: /* 128-bit-readable register */
 421                                 ef4_reado_table(efx, buf, table->offset, i);
 422                                 break;
 423                         case 32: /* 128-bit register, interleaved */
 424                                 ef4_reado_table(efx, buf, table->offset, 2 * i);
 425                                 break;
 426                         default:
 427                                 WARN_ON(1);
 428                                 return;
 429                         }
 430                         buf += size;
 431                 }
 432         }
 433 }
 434 
 435 /**
 436  * ef4_nic_describe_stats - Describe supported statistics for ethtool
 437  * @desc: Array of &struct ef4_hw_stat_desc describing the statistics
 438  * @count: Length of the @desc array
 439  * @mask: Bitmask of which elements of @desc are enabled
 440  * @names: Buffer to copy names to, or %NULL.  The names are copied
 441  *      starting at intervals of %ETH_GSTRING_LEN bytes.
 442  *
 443  * Returns the number of visible statistics, i.e. the number of set
 444  * bits in the first @count bits of @mask for which a name is defined.
 445  */
 446 size_t ef4_nic_describe_stats(const struct ef4_hw_stat_desc *desc, size_t count,
 447                               const unsigned long *mask, u8 *names)
 448 {
 449         size_t visible = 0;
 450         size_t index;
 451 
 452         for_each_set_bit(index, mask, count) {
 453                 if (desc[index].name) {
 454                         if (names) {
 455                                 strlcpy(names, desc[index].name,
 456                                         ETH_GSTRING_LEN);
 457                                 names += ETH_GSTRING_LEN;
 458                         }
 459                         ++visible;
 460                 }
 461         }
 462 
 463         return visible;
 464 }
 465 
 466 /**
 467  * ef4_nic_update_stats - Convert statistics DMA buffer to array of u64
 468  * @desc: Array of &struct ef4_hw_stat_desc describing the DMA buffer
 469  *      layout.  DMA widths of 0, 16, 32 and 64 are supported; where
 470  *      the width is specified as 0 the corresponding element of
 471  *      @stats is not updated.
 472  * @count: Length of the @desc array
 473  * @mask: Bitmask of which elements of @desc are enabled
 474  * @stats: Buffer to update with the converted statistics.  The length
 475  *      of this array must be at least @count.
 476  * @dma_buf: DMA buffer containing hardware statistics
 477  * @accumulate: If set, the converted values will be added rather than
 478  *      directly stored to the corresponding elements of @stats
 479  */
 480 void ef4_nic_update_stats(const struct ef4_hw_stat_desc *desc, size_t count,
 481                           const unsigned long *mask,
 482                           u64 *stats, const void *dma_buf, bool accumulate)
 483 {
 484         size_t index;
 485 
 486         for_each_set_bit(index, mask, count) {
 487                 if (desc[index].dma_width) {
 488                         const void *addr = dma_buf + desc[index].offset;
 489                         u64 val;
 490 
 491                         switch (desc[index].dma_width) {
 492                         case 16:
 493                                 val = le16_to_cpup((__le16 *)addr);
 494                                 break;
 495                         case 32:
 496                                 val = le32_to_cpup((__le32 *)addr);
 497                                 break;
 498                         case 64:
 499                                 val = le64_to_cpup((__le64 *)addr);
 500                                 break;
 501                         default:
 502                                 WARN_ON(1);
 503                                 val = 0;
 504                                 break;
 505                         }
 506 
 507                         if (accumulate)
 508                                 stats[index] += val;
 509                         else
 510                                 stats[index] = val;
 511                 }
 512         }
 513 }
 514 
 515 void ef4_nic_fix_nodesc_drop_stat(struct ef4_nic *efx, u64 *rx_nodesc_drops)
 516 {
 517         /* if down, or this is the first update after coming up */
 518         if (!(efx->net_dev->flags & IFF_UP) || !efx->rx_nodesc_drops_prev_state)
 519                 efx->rx_nodesc_drops_while_down +=
 520                         *rx_nodesc_drops - efx->rx_nodesc_drops_total;
 521         efx->rx_nodesc_drops_total = *rx_nodesc_drops;
 522         efx->rx_nodesc_drops_prev_state = !!(efx->net_dev->flags & IFF_UP);
 523         *rx_nodesc_drops -= efx->rx_nodesc_drops_while_down;
 524 }