LXR linux/drivers/net/ethernet/sfc/nic.c

   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 "ef10_regs.h"
  20#include "farch_regs.h"
  21#include "io.h"
  22#include "workarounds.h"
  23#include "mcdi_pcol.h"
  24
  25/**************************************************************************
  26 *
  27 * Generic buffer handling
  28 * These buffers are used for interrupt status, MAC stats, etc.
  29 *
  30 **************************************************************************/
  31
  32int efx_nic_alloc_buffer(struct efx_nic *efx, struct efx_buffer *buffer,
  33                         unsigned int len, gfp_t gfp_flags)
  34{
  35        buffer->addr = dma_alloc_coherent(&efx->pci_dev->dev, len,
  36                                          &buffer->dma_addr, gfp_flags);
  37        if (!buffer->addr)
  38                return -ENOMEM;
  39        buffer->len = len;
  40        return 0;
  41}
  42
  43void efx_nic_free_buffer(struct efx_nic *efx, struct efx_buffer *buffer)
  44{
  45        if (buffer->addr) {
  46                dma_free_coherent(&efx->pci_dev->dev, buffer->len,
  47                                  buffer->addr, buffer->dma_addr);
  48                buffer->addr = NULL;
  49        }
  50}
  51
  52/* Check whether an event is present in the eventq at the current
  53 * read pointer.  Only useful for self-test.
  54 */
  55bool efx_nic_event_present(struct efx_channel *channel)
  56{
  57        return efx_event_present(efx_event(channel, channel->eventq_read_ptr));
  58}
  59
  60void efx_nic_event_test_start(struct efx_channel *channel)
  61{
  62        channel->event_test_cpu = -1;
  63        smp_wmb();
  64        channel->efx->type->ev_test_generate(channel);
  65}
  66
  67int efx_nic_irq_test_start(struct efx_nic *efx)
  68{
  69        efx->last_irq_cpu = -1;
  70        smp_wmb();
  71        return efx->type->irq_test_generate(efx);
  72}
  73
  74/* Hook interrupt handler(s)
  75 * Try MSI and then legacy interrupts.
  76 */
  77int efx_nic_init_interrupt(struct efx_nic *efx)
  78{
  79        struct efx_channel *channel;
  80        unsigned int n_irqs;
  81        int rc;
  82
  83        if (!EFX_INT_MODE_USE_MSI(efx)) {
  84                rc = request_irq(efx->legacy_irq,
  85                                 efx->type->irq_handle_legacy, IRQF_SHARED,
  86                                 efx->name, efx);
  87                if (rc) {
  88                        netif_err(efx, drv, efx->net_dev,
  89                                  "failed to hook legacy IRQ %d\n",
  90                                  efx->pci_dev->irq);
  91                        goto fail1;
  92                }
  93                return 0;
  94        }
  95
  96#ifdef CONFIG_RFS_ACCEL
  97        if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
  98                efx->net_dev->rx_cpu_rmap =
  99                        alloc_irq_cpu_rmap(efx->n_rx_channels);
 100                if (!efx->net_dev->rx_cpu_rmap) {
 101                        rc = -ENOMEM;
 102                        goto fail1;
 103                }
 104        }
 105#endif
 106
 107        /* Hook MSI or MSI-X interrupt */
 108        n_irqs = 0;
 109        efx_for_each_channel(channel, efx) {
 110                rc = request_irq(channel->irq, efx->type->irq_handle_msi,
 111                                 IRQF_PROBE_SHARED, /* Not shared */
 112                                 efx->msi_context[channel->channel].name,
 113                                 &efx->msi_context[channel->channel]);
 114                if (rc) {
 115                        netif_err(efx, drv, efx->net_dev,
 116                                  "failed to hook IRQ %d\n", channel->irq);
 117                        goto fail2;
 118                }
 119                ++n_irqs;
 120
 121#ifdef CONFIG_RFS_ACCEL
 122                if (efx->interrupt_mode == EFX_INT_MODE_MSIX &&
 123                    channel->channel < efx->n_rx_channels) {
 124                        rc = irq_cpu_rmap_add(efx->net_dev->rx_cpu_rmap,
 125                                              channel->irq);
 126                        if (rc)
 127                                goto fail2;
 128                }
 129#endif
 130        }
 131
 132        efx->irqs_hooked = true;
 133        return 0;
 134
 135 fail2:
 136#ifdef CONFIG_RFS_ACCEL
 137        free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
 138        efx->net_dev->rx_cpu_rmap = NULL;
 139#endif
 140        efx_for_each_channel(channel, efx) {
 141                if (n_irqs-- == 0)
 142                        break;
 143                free_irq(channel->irq, &efx->msi_context[channel->channel]);
 144        }
 145 fail1:
 146        return rc;
 147}
 148
 149void efx_nic_fini_interrupt(struct efx_nic *efx)
 150{
 151        struct efx_channel *channel;
 152
 153#ifdef CONFIG_RFS_ACCEL
 154        free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
 155        efx->net_dev->rx_cpu_rmap = NULL;
 156#endif
 157
 158        if (!efx->irqs_hooked)
 159                return;
 160        if (EFX_INT_MODE_USE_MSI(efx)) {
 161                /* Disable MSI/MSI-X interrupts */
 162                efx_for_each_channel(channel, efx)
 163                        free_irq(channel->irq,
 164                                 &efx->msi_context[channel->channel]);
 165        } else {
 166                /* Disable legacy interrupt */
 167                free_irq(efx->legacy_irq, efx);
 168        }
 169        efx->irqs_hooked = false;
 170}
 171
 172/* Register dump */
 173
 174#define REGISTER_REVISION_FA    1
 175#define REGISTER_REVISION_FB    2
 176#define REGISTER_REVISION_FC    3
 177#define REGISTER_REVISION_FZ    3       /* last Falcon arch revision */
 178#define REGISTER_REVISION_ED    4
 179#define REGISTER_REVISION_EZ    4       /* latest EF10 revision */
 180
 181struct efx_nic_reg {
 182        u32 offset:24;
 183        u32 min_revision:3, max_revision:3;
 184};
 185
 186#define REGISTER(name, arch, min_rev, max_rev) {                        \
 187        arch ## R_ ## min_rev ## max_rev ## _ ## name,                  \
 188        REGISTER_REVISION_ ## arch ## min_rev,                          \
 189        REGISTER_REVISION_ ## arch ## max_rev                           \
 190}
 191#define REGISTER_AA(name) REGISTER(name, F, A, A)
 192#define REGISTER_AB(name) REGISTER(name, F, A, B)
 193#define REGISTER_AZ(name) REGISTER(name, F, A, Z)
 194#define REGISTER_BB(name) REGISTER(name, F, B, B)
 195#define REGISTER_BZ(name) REGISTER(name, F, B, Z)
 196#define REGISTER_CZ(name) REGISTER(name, F, C, Z)
 197#define REGISTER_DZ(name) REGISTER(name, E, D, Z)
 198
 199static const struct efx_nic_reg efx_nic_regs[] = {
 200        REGISTER_AZ(ADR_REGION),
 201        REGISTER_AZ(INT_EN_KER),
 202        REGISTER_BZ(INT_EN_CHAR),
 203        REGISTER_AZ(INT_ADR_KER),
 204        REGISTER_BZ(INT_ADR_CHAR),
 205        /* INT_ACK_KER is WO */
 206        /* INT_ISR0 is RC */
 207        REGISTER_AZ(HW_INIT),
 208        REGISTER_CZ(USR_EV_CFG),
 209        REGISTER_AB(EE_SPI_HCMD),
 210        REGISTER_AB(EE_SPI_HADR),
 211        REGISTER_AB(EE_SPI_HDATA),
 212        REGISTER_AB(EE_BASE_PAGE),
 213        REGISTER_AB(EE_VPD_CFG0),
 214        /* EE_VPD_SW_CNTL and EE_VPD_SW_DATA are not used */
 215        /* PMBX_DBG_IADDR and PBMX_DBG_IDATA are indirect */
 216        /* PCIE_CORE_INDIRECT is indirect */
 217        REGISTER_AB(NIC_STAT),
 218        REGISTER_AB(GPIO_CTL),
 219        REGISTER_AB(GLB_CTL),
 220        /* FATAL_INTR_KER and FATAL_INTR_CHAR are partly RC */
 221        REGISTER_BZ(DP_CTRL),
 222        REGISTER_AZ(MEM_STAT),
 223        REGISTER_AZ(CS_DEBUG),
 224        REGISTER_AZ(ALTERA_BUILD),
 225        REGISTER_AZ(CSR_SPARE),
 226        REGISTER_AB(PCIE_SD_CTL0123),
 227        REGISTER_AB(PCIE_SD_CTL45),
 228        REGISTER_AB(PCIE_PCS_CTL_STAT),
 229        /* DEBUG_DATA_OUT is not used */
 230        /* DRV_EV is WO */
 231        REGISTER_AZ(EVQ_CTL),
 232        REGISTER_AZ(EVQ_CNT1),
 233        REGISTER_AZ(EVQ_CNT2),
 234        REGISTER_AZ(BUF_TBL_CFG),
 235        REGISTER_AZ(SRM_RX_DC_CFG),
 236        REGISTER_AZ(SRM_TX_DC_CFG),
 237        REGISTER_AZ(SRM_CFG),
 238        /* BUF_TBL_UPD is WO */
 239        REGISTER_AZ(SRM_UPD_EVQ),
 240        REGISTER_AZ(SRAM_PARITY),
 241        REGISTER_AZ(RX_CFG),
 242        REGISTER_BZ(RX_FILTER_CTL),
 243        /* RX_FLUSH_DESCQ is WO */
 244        REGISTER_AZ(RX_DC_CFG),
 245        REGISTER_AZ(RX_DC_PF_WM),
 246        REGISTER_BZ(RX_RSS_TKEY),
 247        /* RX_NODESC_DROP is RC */
 248        REGISTER_AA(RX_SELF_RST),
 249        /* RX_DEBUG, RX_PUSH_DROP are not used */
 250        REGISTER_CZ(RX_RSS_IPV6_REG1),
 251        REGISTER_CZ(RX_RSS_IPV6_REG2),
 252        REGISTER_CZ(RX_RSS_IPV6_REG3),
 253        /* TX_FLUSH_DESCQ is WO */
 254        REGISTER_AZ(TX_DC_CFG),
 255        REGISTER_AA(TX_CHKSM_CFG),
 256        REGISTER_AZ(TX_CFG),
 257        /* TX_PUSH_DROP is not used */
 258        REGISTER_AZ(TX_RESERVED),
 259        REGISTER_BZ(TX_PACE),
 260        /* TX_PACE_DROP_QID is RC */
 261        REGISTER_BB(TX_VLAN),
 262        REGISTER_BZ(TX_IPFIL_PORTEN),
 263        REGISTER_AB(MD_TXD),
 264        REGISTER_AB(MD_RXD),
 265        REGISTER_AB(MD_CS),
 266        REGISTER_AB(MD_PHY_ADR),
 267        REGISTER_AB(MD_ID),
 268        /* MD_STAT is RC */
 269        REGISTER_AB(MAC_STAT_DMA),
 270        REGISTER_AB(MAC_CTRL),
 271        REGISTER_BB(GEN_MODE),
 272        REGISTER_AB(MAC_MC_HASH_REG0),
 273        REGISTER_AB(MAC_MC_HASH_REG1),
 274        REGISTER_AB(GM_CFG1),
 275        REGISTER_AB(GM_CFG2),
 276        /* GM_IPG and GM_HD are not used */
 277        REGISTER_AB(GM_MAX_FLEN),
 278        /* GM_TEST is not used */
 279        REGISTER_AB(GM_ADR1),
 280        REGISTER_AB(GM_ADR2),
 281        REGISTER_AB(GMF_CFG0),
 282        REGISTER_AB(GMF_CFG1),
 283        REGISTER_AB(GMF_CFG2),
 284        REGISTER_AB(GMF_CFG3),
 285        REGISTER_AB(GMF_CFG4),
 286        REGISTER_AB(GMF_CFG5),
 287        REGISTER_BB(TX_SRC_MAC_CTL),
 288        REGISTER_AB(XM_ADR_LO),
 289        REGISTER_AB(XM_ADR_HI),
 290        REGISTER_AB(XM_GLB_CFG),
 291        REGISTER_AB(XM_TX_CFG),
 292        REGISTER_AB(XM_RX_CFG),
 293        REGISTER_AB(XM_MGT_INT_MASK),
 294        REGISTER_AB(XM_FC),
 295        REGISTER_AB(XM_PAUSE_TIME),
 296        REGISTER_AB(XM_TX_PARAM),
 297        REGISTER_AB(XM_RX_PARAM),
 298        /* XM_MGT_INT_MSK (note no 'A') is RC */
 299        REGISTER_AB(XX_PWR_RST),
 300        REGISTER_AB(XX_SD_CTL),
 301        REGISTER_AB(XX_TXDRV_CTL),
 302        /* XX_PRBS_CTL, XX_PRBS_CHK and XX_PRBS_ERR are not used */
 303        /* XX_CORE_STAT is partly RC */
 304        REGISTER_DZ(BIU_HW_REV_ID),
 305        REGISTER_DZ(MC_DB_LWRD),
 306        REGISTER_DZ(MC_DB_HWRD),
 307};
 308
 309struct efx_nic_reg_table {
 310        u32 offset:24;
 311        u32 min_revision:3, max_revision:3;
 312        u32 step:6, rows:21;
 313};
 314
 315#define REGISTER_TABLE_DIMENSIONS(_, offset, arch, min_rev, max_rev, step, rows) { \
 316        offset,                                                         \
 317        REGISTER_REVISION_ ## arch ## min_rev,                          \
 318        REGISTER_REVISION_ ## arch ## max_rev,                          \
 319        step, rows                                                      \
 320}
 321#define REGISTER_TABLE(name, arch, min_rev, max_rev)                    \
 322        REGISTER_TABLE_DIMENSIONS(                                      \
 323                name, arch ## R_ ## min_rev ## max_rev ## _ ## name,    \
 324                arch, min_rev, max_rev,                                 \
 325                arch ## R_ ## min_rev ## max_rev ## _ ## name ## _STEP, \
 326                arch ## R_ ## min_rev ## max_rev ## _ ## name ## _ROWS)
 327#define REGISTER_TABLE_AA(name) REGISTER_TABLE(name, F, A, A)
 328#define REGISTER_TABLE_AZ(name) REGISTER_TABLE(name, F, A, Z)
 329#define REGISTER_TABLE_BB(name) REGISTER_TABLE(name, F, B, B)
 330#define REGISTER_TABLE_BZ(name) REGISTER_TABLE(name, F, B, Z)
 331#define REGISTER_TABLE_BB_CZ(name)                                      \
 332        REGISTER_TABLE_DIMENSIONS(name, FR_BZ_ ## name, F, B, B,        \
 333                                  FR_BZ_ ## name ## _STEP,              \
 334                                  FR_BB_ ## name ## _ROWS),             \
 335        REGISTER_TABLE_DIMENSIONS(name, FR_BZ_ ## name, F, C, Z,        \
 336                                  FR_BZ_ ## name ## _STEP,              \
 337                                  FR_CZ_ ## name ## _ROWS)
 338#define REGISTER_TABLE_CZ(name) REGISTER_TABLE(name, F, C, Z)
 339#define REGISTER_TABLE_DZ(name) REGISTER_TABLE(name, E, D, Z)
 340
 341static const struct efx_nic_reg_table efx_nic_reg_tables[] = {
 342        /* DRIVER is not used */
 343        /* EVQ_RPTR, TIMER_COMMAND, USR_EV and {RX,TX}_DESC_UPD are WO */
 344        REGISTER_TABLE_BB(TX_IPFIL_TBL),
 345        REGISTER_TABLE_BB(TX_SRC_MAC_TBL),
 346        REGISTER_TABLE_AA(RX_DESC_PTR_TBL_KER),
 347        REGISTER_TABLE_BB_CZ(RX_DESC_PTR_TBL),
 348        REGISTER_TABLE_AA(TX_DESC_PTR_TBL_KER),
 349        REGISTER_TABLE_BB_CZ(TX_DESC_PTR_TBL),
 350        REGISTER_TABLE_AA(EVQ_PTR_TBL_KER),
 351        REGISTER_TABLE_BB_CZ(EVQ_PTR_TBL),
 352        /* We can't reasonably read all of the buffer table (up to 8MB!).
 353         * However this driver will only use a few entries.  Reading
 354         * 1K entries allows for some expansion of queue count and
 355         * size before we need to change the version. */
 356        REGISTER_TABLE_DIMENSIONS(BUF_FULL_TBL_KER, FR_AA_BUF_FULL_TBL_KER,
 357                                  F, A, A, 8, 1024),
 358        REGISTER_TABLE_DIMENSIONS(BUF_FULL_TBL, FR_BZ_BUF_FULL_TBL,
 359                                  F, B, Z, 8, 1024),
 360        REGISTER_TABLE_CZ(RX_MAC_FILTER_TBL0),
 361        REGISTER_TABLE_BB_CZ(TIMER_TBL),
 362        REGISTER_TABLE_BB_CZ(TX_PACE_TBL),
 363        REGISTER_TABLE_BZ(RX_INDIRECTION_TBL),
 364        /* TX_FILTER_TBL0 is huge and not used by this driver */
 365        REGISTER_TABLE_CZ(TX_MAC_FILTER_TBL0),
 366        REGISTER_TABLE_CZ(MC_TREG_SMEM),
 367        /* MSIX_PBA_TABLE is not mapped */
 368        /* SRM_DBG is not mapped (and is redundant with BUF_FLL_TBL) */
 369        REGISTER_TABLE_BZ(RX_FILTER_TBL0),
 370        REGISTER_TABLE_DZ(BIU_MC_SFT_STATUS),
 371};
 372
 373size_t efx_nic_get_regs_len(struct efx_nic *efx)
 374{
 375        const struct efx_nic_reg *reg;
 376        const struct efx_nic_reg_table *table;
 377        size_t len = 0;
 378
 379        for (reg = efx_nic_regs;
 380             reg < efx_nic_regs + ARRAY_SIZE(efx_nic_regs);
 381             reg++)
 382                if (efx->type->revision >= reg->min_revision &&
 383                    efx->type->revision <= reg->max_revision)
 384                        len += sizeof(efx_oword_t);
 385
 386        for (table = efx_nic_reg_tables;
 387             table < efx_nic_reg_tables + ARRAY_SIZE(efx_nic_reg_tables);
 388             table++)
 389                if (efx->type->revision >= table->min_revision &&
 390                    efx->type->revision <= table->max_revision)
 391                        len += table->rows * min_t(size_t, table->step, 16);
 392
 393        return len;
 394}
 395
 396void efx_nic_get_regs(struct efx_nic *efx, void *buf)
 397{
 398        const struct efx_nic_reg *reg;
 399        const struct efx_nic_reg_table *table;
 400
 401        for (reg = efx_nic_regs;
 402             reg < efx_nic_regs + ARRAY_SIZE(efx_nic_regs);
 403             reg++) {
 404                if (efx->type->revision >= reg->min_revision &&
 405                    efx->type->revision <= reg->max_revision) {
 406                        efx_reado(efx, (efx_oword_t *)buf, reg->offset);
 407                        buf += sizeof(efx_oword_t);
 408                }
 409        }
 410
 411        for (table = efx_nic_reg_tables;
 412             table < efx_nic_reg_tables + ARRAY_SIZE(efx_nic_reg_tables);
 413             table++) {
 414                size_t size, i;
 415
 416                if (!(efx->type->revision >= table->min_revision &&
 417                      efx->type->revision <= table->max_revision))
 418                        continue;
 419
 420                size = min_t(size_t, table->step, 16);
 421
 422                for (i = 0; i < table->rows; i++) {
 423                        switch (table->step) {
 424                        case 4: /* 32-bit SRAM */
 425                                efx_readd(efx, buf, table->offset + 4 * i);
 426                                break;
 427                        case 8: /* 64-bit SRAM */
 428                                efx_sram_readq(efx,
 429                                               efx->membase + table->offset,
 430                                               buf, i);
 431                                break;
 432                        case 16: /* 128-bit-readable register */
 433                                efx_reado_table(efx, buf, table->offset, i);
 434                                break;
 435                        case 32: /* 128-bit register, interleaved */
 436                                efx_reado_table(efx, buf, table->offset, 2 * i);
 437                                break;
 438                        default:
 439                                WARN_ON(1);
 440                                return;
 441                        }
 442                        buf += size;
 443                }
 444        }
 445}
 446
 447/**
 448 * efx_nic_describe_stats - Describe supported statistics for ethtool
 449 * @desc: Array of &struct efx_hw_stat_desc describing the statistics
 450 * @count: Length of the @desc array
 451 * @mask: Bitmask of which elements of @desc are enabled
 452 * @names: Buffer to copy names to, or %NULL.  The names are copied
 453 *      starting at intervals of %ETH_GSTRING_LEN bytes.
 454 *
 455 * Returns the number of visible statistics, i.e. the number of set
 456 * bits in the first @count bits of @mask for which a name is defined.
 457 */
 458size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
 459                              const unsigned long *mask, u8 *names)
 460{
 461        size_t visible = 0;
 462        size_t index;
 463
 464        for_each_set_bit(index, mask, count) {
 465                if (desc[index].name) {
 466                        if (names) {
 467                                strlcpy(names, desc[index].name,
 468                                        ETH_GSTRING_LEN);
 469                                names += ETH_GSTRING_LEN;
 470                        }
 471                        ++visible;
 472                }
 473        }
 474
 475        return visible;
 476}
 477
 478/**
 479 * efx_nic_copy_stats - Copy stats from the DMA buffer in to an
 480 *      intermediate buffer. This is used to get a consistent
 481 *      set of stats while the DMA buffer can be written at any time
 482 *      by the NIC.
 483 * @efx: The associated NIC.
 484 * @dest: Destination buffer. Must be the same size as the DMA buffer.
 485 */
 486int efx_nic_copy_stats(struct efx_nic *efx, __le64 *dest)
 487{
 488        __le64 *dma_stats = efx->stats_buffer.addr;
 489        __le64 generation_start, generation_end;
 490        int rc = 0, retry;
 491
 492        if (!dest)
 493                return 0;
 494
 495        if (!dma_stats)
 496                goto return_zeroes;
 497
 498        /* If we're unlucky enough to read statistics during the DMA, wait
 499         * up to 10ms for it to finish (typically takes <500us)
 500         */
 501        for (retry = 0; retry < 100; ++retry) {
 502                generation_end = dma_stats[efx->num_mac_stats - 1];
 503                if (generation_end == EFX_MC_STATS_GENERATION_INVALID)
 504                        goto return_zeroes;
 505                rmb();
 506                memcpy(dest, dma_stats, efx->num_mac_stats * sizeof(__le64));
 507                rmb();
 508                generation_start = dma_stats[MC_CMD_MAC_GENERATION_START];
 509                if (generation_end == generation_start)
 510                        return 0; /* return good data */
 511                udelay(100);
 512        }
 513
 514        rc = -EIO;
 515
 516return_zeroes:
 517        memset(dest, 0, efx->num_mac_stats * sizeof(u64));
 518        return rc;
 519}
 520
 521/**
 522 * efx_nic_update_stats - Convert statistics DMA buffer to array of u64
 523 * @desc: Array of &struct efx_hw_stat_desc describing the DMA buffer
 524 *      layout.  DMA widths of 0, 16, 32 and 64 are supported; where
 525 *      the width is specified as 0 the corresponding element of
 526 *      @stats is not updated.
 527 * @count: Length of the @desc array
 528 * @mask: Bitmask of which elements of @desc are enabled
 529 * @stats: Buffer to update with the converted statistics.  The length
 530 *      of this array must be at least @count.
 531 * @dma_buf: DMA buffer containing hardware statistics
 532 * @accumulate: If set, the converted values will be added rather than
 533 *      directly stored to the corresponding elements of @stats
 534 */
 535void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count,
 536                          const unsigned long *mask,
 537                          u64 *stats, const void *dma_buf, bool accumulate)
 538{
 539        size_t index;
 540
 541        for_each_set_bit(index, mask, count) {
 542                if (desc[index].dma_width) {
 543                        const void *addr = dma_buf + desc[index].offset;
 544                        u64 val;
 545
 546                        switch (desc[index].dma_width) {
 547                        case 16:
 548                                val = le16_to_cpup((__le16 *)addr);
 549                                break;
 550                        case 32:
 551                                val = le32_to_cpup((__le32 *)addr);
 552                                break;
 553                        case 64:
 554                                val = le64_to_cpup((__le64 *)addr);
 555                                break;
 556                        default:
 557                                WARN_ON(1);
 558                                val = 0;
 559                                break;
 560                        }
 561
 562                        if (accumulate)
 563                                stats[index] += val;
 564                        else
 565                                stats[index] = val;
 566                }
 567        }
 568}
 569
 570void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *rx_nodesc_drops)
 571{
 572        /* if down, or this is the first update after coming up */
 573        if (!(efx->net_dev->flags & IFF_UP) || !efx->rx_nodesc_drops_prev_state)
 574                efx->rx_nodesc_drops_while_down +=
 575                        *rx_nodesc_drops - efx->rx_nodesc_drops_total;
 576        efx->rx_nodesc_drops_total = *rx_nodesc_drops;
 577        efx->rx_nodesc_drops_prev_state = !!(efx->net_dev->flags & IFF_UP);
 578        *rx_nodesc_drops -= efx->rx_nodesc_drops_while_down;
 579}
 580