xref: /openbmc/linux/drivers/net/ethernet/sfc/nic.c (revision 4eb5928d)
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 
32 int 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 
43 void 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  */
55 bool efx_nic_event_present(struct efx_channel *channel)
56 {
57 	return efx_event_present(efx_event(channel, channel->eventq_read_ptr));
58 }
59 
60 void 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 
67 int 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  */
77 int 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 	return 0;
133 
134  fail2:
135 #ifdef CONFIG_RFS_ACCEL
136 	free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
137 	efx->net_dev->rx_cpu_rmap = NULL;
138 #endif
139 	efx_for_each_channel(channel, efx) {
140 		if (n_irqs-- == 0)
141 			break;
142 		free_irq(channel->irq, &efx->msi_context[channel->channel]);
143 	}
144  fail1:
145 	return rc;
146 }
147 
148 void efx_nic_fini_interrupt(struct efx_nic *efx)
149 {
150 	struct efx_channel *channel;
151 
152 #ifdef CONFIG_RFS_ACCEL
153 	free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
154 	efx->net_dev->rx_cpu_rmap = NULL;
155 #endif
156 
157 	if (EFX_INT_MODE_USE_MSI(efx)) {
158 		/* Disable MSI/MSI-X interrupts */
159 		efx_for_each_channel(channel, efx)
160 			free_irq(channel->irq,
161 				 &efx->msi_context[channel->channel]);
162 	} else {
163 		/* Disable legacy interrupt */
164 		free_irq(efx->legacy_irq, efx);
165 	}
166 }
167 
168 /* Register dump */
169 
170 #define REGISTER_REVISION_FA	1
171 #define REGISTER_REVISION_FB	2
172 #define REGISTER_REVISION_FC	3
173 #define REGISTER_REVISION_FZ	3	/* last Falcon arch revision */
174 #define REGISTER_REVISION_ED	4
175 #define REGISTER_REVISION_EZ	4	/* latest EF10 revision */
176 
177 struct efx_nic_reg {
178 	u32 offset:24;
179 	u32 min_revision:3, max_revision:3;
180 };
181 
182 #define REGISTER(name, arch, min_rev, max_rev) {			\
183 	arch ## R_ ## min_rev ## max_rev ## _ ## name,			\
184 	REGISTER_REVISION_ ## arch ## min_rev,				\
185 	REGISTER_REVISION_ ## arch ## max_rev				\
186 }
187 #define REGISTER_AA(name) REGISTER(name, F, A, A)
188 #define REGISTER_AB(name) REGISTER(name, F, A, B)
189 #define REGISTER_AZ(name) REGISTER(name, F, A, Z)
190 #define REGISTER_BB(name) REGISTER(name, F, B, B)
191 #define REGISTER_BZ(name) REGISTER(name, F, B, Z)
192 #define REGISTER_CZ(name) REGISTER(name, F, C, Z)
193 #define REGISTER_DZ(name) REGISTER(name, E, D, Z)
194 
195 static const struct efx_nic_reg efx_nic_regs[] = {
196 	REGISTER_AZ(ADR_REGION),
197 	REGISTER_AZ(INT_EN_KER),
198 	REGISTER_BZ(INT_EN_CHAR),
199 	REGISTER_AZ(INT_ADR_KER),
200 	REGISTER_BZ(INT_ADR_CHAR),
201 	/* INT_ACK_KER is WO */
202 	/* INT_ISR0 is RC */
203 	REGISTER_AZ(HW_INIT),
204 	REGISTER_CZ(USR_EV_CFG),
205 	REGISTER_AB(EE_SPI_HCMD),
206 	REGISTER_AB(EE_SPI_HADR),
207 	REGISTER_AB(EE_SPI_HDATA),
208 	REGISTER_AB(EE_BASE_PAGE),
209 	REGISTER_AB(EE_VPD_CFG0),
210 	/* EE_VPD_SW_CNTL and EE_VPD_SW_DATA are not used */
211 	/* PMBX_DBG_IADDR and PBMX_DBG_IDATA are indirect */
212 	/* PCIE_CORE_INDIRECT is indirect */
213 	REGISTER_AB(NIC_STAT),
214 	REGISTER_AB(GPIO_CTL),
215 	REGISTER_AB(GLB_CTL),
216 	/* FATAL_INTR_KER and FATAL_INTR_CHAR are partly RC */
217 	REGISTER_BZ(DP_CTRL),
218 	REGISTER_AZ(MEM_STAT),
219 	REGISTER_AZ(CS_DEBUG),
220 	REGISTER_AZ(ALTERA_BUILD),
221 	REGISTER_AZ(CSR_SPARE),
222 	REGISTER_AB(PCIE_SD_CTL0123),
223 	REGISTER_AB(PCIE_SD_CTL45),
224 	REGISTER_AB(PCIE_PCS_CTL_STAT),
225 	/* DEBUG_DATA_OUT is not used */
226 	/* DRV_EV is WO */
227 	REGISTER_AZ(EVQ_CTL),
228 	REGISTER_AZ(EVQ_CNT1),
229 	REGISTER_AZ(EVQ_CNT2),
230 	REGISTER_AZ(BUF_TBL_CFG),
231 	REGISTER_AZ(SRM_RX_DC_CFG),
232 	REGISTER_AZ(SRM_TX_DC_CFG),
233 	REGISTER_AZ(SRM_CFG),
234 	/* BUF_TBL_UPD is WO */
235 	REGISTER_AZ(SRM_UPD_EVQ),
236 	REGISTER_AZ(SRAM_PARITY),
237 	REGISTER_AZ(RX_CFG),
238 	REGISTER_BZ(RX_FILTER_CTL),
239 	/* RX_FLUSH_DESCQ is WO */
240 	REGISTER_AZ(RX_DC_CFG),
241 	REGISTER_AZ(RX_DC_PF_WM),
242 	REGISTER_BZ(RX_RSS_TKEY),
243 	/* RX_NODESC_DROP is RC */
244 	REGISTER_AA(RX_SELF_RST),
245 	/* RX_DEBUG, RX_PUSH_DROP are not used */
246 	REGISTER_CZ(RX_RSS_IPV6_REG1),
247 	REGISTER_CZ(RX_RSS_IPV6_REG2),
248 	REGISTER_CZ(RX_RSS_IPV6_REG3),
249 	/* TX_FLUSH_DESCQ is WO */
250 	REGISTER_AZ(TX_DC_CFG),
251 	REGISTER_AA(TX_CHKSM_CFG),
252 	REGISTER_AZ(TX_CFG),
253 	/* TX_PUSH_DROP is not used */
254 	REGISTER_AZ(TX_RESERVED),
255 	REGISTER_BZ(TX_PACE),
256 	/* TX_PACE_DROP_QID is RC */
257 	REGISTER_BB(TX_VLAN),
258 	REGISTER_BZ(TX_IPFIL_PORTEN),
259 	REGISTER_AB(MD_TXD),
260 	REGISTER_AB(MD_RXD),
261 	REGISTER_AB(MD_CS),
262 	REGISTER_AB(MD_PHY_ADR),
263 	REGISTER_AB(MD_ID),
264 	/* MD_STAT is RC */
265 	REGISTER_AB(MAC_STAT_DMA),
266 	REGISTER_AB(MAC_CTRL),
267 	REGISTER_BB(GEN_MODE),
268 	REGISTER_AB(MAC_MC_HASH_REG0),
269 	REGISTER_AB(MAC_MC_HASH_REG1),
270 	REGISTER_AB(GM_CFG1),
271 	REGISTER_AB(GM_CFG2),
272 	/* GM_IPG and GM_HD are not used */
273 	REGISTER_AB(GM_MAX_FLEN),
274 	/* GM_TEST is not used */
275 	REGISTER_AB(GM_ADR1),
276 	REGISTER_AB(GM_ADR2),
277 	REGISTER_AB(GMF_CFG0),
278 	REGISTER_AB(GMF_CFG1),
279 	REGISTER_AB(GMF_CFG2),
280 	REGISTER_AB(GMF_CFG3),
281 	REGISTER_AB(GMF_CFG4),
282 	REGISTER_AB(GMF_CFG5),
283 	REGISTER_BB(TX_SRC_MAC_CTL),
284 	REGISTER_AB(XM_ADR_LO),
285 	REGISTER_AB(XM_ADR_HI),
286 	REGISTER_AB(XM_GLB_CFG),
287 	REGISTER_AB(XM_TX_CFG),
288 	REGISTER_AB(XM_RX_CFG),
289 	REGISTER_AB(XM_MGT_INT_MASK),
290 	REGISTER_AB(XM_FC),
291 	REGISTER_AB(XM_PAUSE_TIME),
292 	REGISTER_AB(XM_TX_PARAM),
293 	REGISTER_AB(XM_RX_PARAM),
294 	/* XM_MGT_INT_MSK (note no 'A') is RC */
295 	REGISTER_AB(XX_PWR_RST),
296 	REGISTER_AB(XX_SD_CTL),
297 	REGISTER_AB(XX_TXDRV_CTL),
298 	/* XX_PRBS_CTL, XX_PRBS_CHK and XX_PRBS_ERR are not used */
299 	/* XX_CORE_STAT is partly RC */
300 	REGISTER_DZ(BIU_HW_REV_ID),
301 	REGISTER_DZ(MC_DB_LWRD),
302 	REGISTER_DZ(MC_DB_HWRD),
303 };
304 
305 struct efx_nic_reg_table {
306 	u32 offset:24;
307 	u32 min_revision:3, max_revision:3;
308 	u32 step:6, rows:21;
309 };
310 
311 #define REGISTER_TABLE_DIMENSIONS(_, offset, arch, min_rev, max_rev, step, rows) { \
312 	offset,								\
313 	REGISTER_REVISION_ ## arch ## min_rev,				\
314 	REGISTER_REVISION_ ## arch ## max_rev,				\
315 	step, rows							\
316 }
317 #define REGISTER_TABLE(name, arch, min_rev, max_rev)			\
318 	REGISTER_TABLE_DIMENSIONS(					\
319 		name, arch ## R_ ## min_rev ## max_rev ## _ ## name,	\
320 		arch, min_rev, max_rev,					\
321 		arch ## R_ ## min_rev ## max_rev ## _ ## name ## _STEP,	\
322 		arch ## R_ ## min_rev ## max_rev ## _ ## name ## _ROWS)
323 #define REGISTER_TABLE_AA(name) REGISTER_TABLE(name, F, A, A)
324 #define REGISTER_TABLE_AZ(name) REGISTER_TABLE(name, F, A, Z)
325 #define REGISTER_TABLE_BB(name) REGISTER_TABLE(name, F, B, B)
326 #define REGISTER_TABLE_BZ(name) REGISTER_TABLE(name, F, B, Z)
327 #define REGISTER_TABLE_BB_CZ(name)					\
328 	REGISTER_TABLE_DIMENSIONS(name, FR_BZ_ ## name, F, B, B,	\
329 				  FR_BZ_ ## name ## _STEP,		\
330 				  FR_BB_ ## name ## _ROWS),		\
331 	REGISTER_TABLE_DIMENSIONS(name, FR_BZ_ ## name, F, C, Z,	\
332 				  FR_BZ_ ## name ## _STEP,		\
333 				  FR_CZ_ ## name ## _ROWS)
334 #define REGISTER_TABLE_CZ(name) REGISTER_TABLE(name, F, C, Z)
335 #define REGISTER_TABLE_DZ(name) REGISTER_TABLE(name, E, D, Z)
336 
337 static const struct efx_nic_reg_table efx_nic_reg_tables[] = {
338 	/* DRIVER is not used */
339 	/* EVQ_RPTR, TIMER_COMMAND, USR_EV and {RX,TX}_DESC_UPD are WO */
340 	REGISTER_TABLE_BB(TX_IPFIL_TBL),
341 	REGISTER_TABLE_BB(TX_SRC_MAC_TBL),
342 	REGISTER_TABLE_AA(RX_DESC_PTR_TBL_KER),
343 	REGISTER_TABLE_BB_CZ(RX_DESC_PTR_TBL),
344 	REGISTER_TABLE_AA(TX_DESC_PTR_TBL_KER),
345 	REGISTER_TABLE_BB_CZ(TX_DESC_PTR_TBL),
346 	REGISTER_TABLE_AA(EVQ_PTR_TBL_KER),
347 	REGISTER_TABLE_BB_CZ(EVQ_PTR_TBL),
348 	/* We can't reasonably read all of the buffer table (up to 8MB!).
349 	 * However this driver will only use a few entries.  Reading
350 	 * 1K entries allows for some expansion of queue count and
351 	 * size before we need to change the version. */
352 	REGISTER_TABLE_DIMENSIONS(BUF_FULL_TBL_KER, FR_AA_BUF_FULL_TBL_KER,
353 				  F, A, A, 8, 1024),
354 	REGISTER_TABLE_DIMENSIONS(BUF_FULL_TBL, FR_BZ_BUF_FULL_TBL,
355 				  F, B, Z, 8, 1024),
356 	REGISTER_TABLE_CZ(RX_MAC_FILTER_TBL0),
357 	REGISTER_TABLE_BB_CZ(TIMER_TBL),
358 	REGISTER_TABLE_BB_CZ(TX_PACE_TBL),
359 	REGISTER_TABLE_BZ(RX_INDIRECTION_TBL),
360 	/* TX_FILTER_TBL0 is huge and not used by this driver */
361 	REGISTER_TABLE_CZ(TX_MAC_FILTER_TBL0),
362 	REGISTER_TABLE_CZ(MC_TREG_SMEM),
363 	/* MSIX_PBA_TABLE is not mapped */
364 	/* SRM_DBG is not mapped (and is redundant with BUF_FLL_TBL) */
365 	REGISTER_TABLE_BZ(RX_FILTER_TBL0),
366 	REGISTER_TABLE_DZ(BIU_MC_SFT_STATUS),
367 };
368 
369 size_t efx_nic_get_regs_len(struct efx_nic *efx)
370 {
371 	const struct efx_nic_reg *reg;
372 	const struct efx_nic_reg_table *table;
373 	size_t len = 0;
374 
375 	for (reg = efx_nic_regs;
376 	     reg < efx_nic_regs + ARRAY_SIZE(efx_nic_regs);
377 	     reg++)
378 		if (efx->type->revision >= reg->min_revision &&
379 		    efx->type->revision <= reg->max_revision)
380 			len += sizeof(efx_oword_t);
381 
382 	for (table = efx_nic_reg_tables;
383 	     table < efx_nic_reg_tables + ARRAY_SIZE(efx_nic_reg_tables);
384 	     table++)
385 		if (efx->type->revision >= table->min_revision &&
386 		    efx->type->revision <= table->max_revision)
387 			len += table->rows * min_t(size_t, table->step, 16);
388 
389 	return len;
390 }
391 
392 void efx_nic_get_regs(struct efx_nic *efx, void *buf)
393 {
394 	const struct efx_nic_reg *reg;
395 	const struct efx_nic_reg_table *table;
396 
397 	for (reg = efx_nic_regs;
398 	     reg < efx_nic_regs + ARRAY_SIZE(efx_nic_regs);
399 	     reg++) {
400 		if (efx->type->revision >= reg->min_revision &&
401 		    efx->type->revision <= reg->max_revision) {
402 			efx_reado(efx, (efx_oword_t *)buf, reg->offset);
403 			buf += sizeof(efx_oword_t);
404 		}
405 	}
406 
407 	for (table = efx_nic_reg_tables;
408 	     table < efx_nic_reg_tables + ARRAY_SIZE(efx_nic_reg_tables);
409 	     table++) {
410 		size_t size, i;
411 
412 		if (!(efx->type->revision >= table->min_revision &&
413 		      efx->type->revision <= table->max_revision))
414 			continue;
415 
416 		size = min_t(size_t, table->step, 16);
417 
418 		for (i = 0; i < table->rows; i++) {
419 			switch (table->step) {
420 			case 4: /* 32-bit SRAM */
421 				efx_readd(efx, buf, table->offset + 4 * i);
422 				break;
423 			case 8: /* 64-bit SRAM */
424 				efx_sram_readq(efx,
425 					       efx->membase + table->offset,
426 					       buf, i);
427 				break;
428 			case 16: /* 128-bit-readable register */
429 				efx_reado_table(efx, buf, table->offset, i);
430 				break;
431 			case 32: /* 128-bit register, interleaved */
432 				efx_reado_table(efx, buf, table->offset, 2 * i);
433 				break;
434 			default:
435 				WARN_ON(1);
436 				return;
437 			}
438 			buf += size;
439 		}
440 	}
441 }
442 
443 /**
444  * efx_nic_describe_stats - Describe supported statistics for ethtool
445  * @desc: Array of &struct efx_hw_stat_desc describing the statistics
446  * @count: Length of the @desc array
447  * @mask: Bitmask of which elements of @desc are enabled
448  * @names: Buffer to copy names to, or %NULL.  The names are copied
449  *	starting at intervals of %ETH_GSTRING_LEN bytes.
450  *
451  * Returns the number of visible statistics, i.e. the number of set
452  * bits in the first @count bits of @mask for which a name is defined.
453  */
454 size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
455 			      const unsigned long *mask, u8 *names)
456 {
457 	size_t visible = 0;
458 	size_t index;
459 
460 	for_each_set_bit(index, mask, count) {
461 		if (desc[index].name) {
462 			if (names) {
463 				strlcpy(names, desc[index].name,
464 					ETH_GSTRING_LEN);
465 				names += ETH_GSTRING_LEN;
466 			}
467 			++visible;
468 		}
469 	}
470 
471 	return visible;
472 }
473 
474 /**
475  * efx_nic_copy_stats - Copy stats from the DMA buffer in to an
476  *	intermediate buffer. This is used to get a consistent
477  *	set of stats while the DMA buffer can be written at any time
478  *	by the NIC.
479  * @efx: The associated NIC.
480  * @dest: Destination buffer. Must be the same size as the DMA buffer.
481  */
482 int efx_nic_copy_stats(struct efx_nic *efx, __le64 *dest)
483 {
484 	__le64 *dma_stats = efx->stats_buffer.addr;
485 	__le64 generation_start, generation_end;
486 	int rc = 0, retry;
487 
488 	if (!dest)
489 		return 0;
490 
491 	if (!dma_stats)
492 		goto return_zeroes;
493 
494 	/* If we're unlucky enough to read statistics during the DMA, wait
495 	 * up to 10ms for it to finish (typically takes <500us)
496 	 */
497 	for (retry = 0; retry < 100; ++retry) {
498 		generation_end = dma_stats[efx->num_mac_stats - 1];
499 		if (generation_end == EFX_MC_STATS_GENERATION_INVALID)
500 			goto return_zeroes;
501 		rmb();
502 		memcpy(dest, dma_stats, efx->num_mac_stats * sizeof(__le64));
503 		rmb();
504 		generation_start = dma_stats[MC_CMD_MAC_GENERATION_START];
505 		if (generation_end == generation_start)
506 			return 0; /* return good data */
507 		udelay(100);
508 	}
509 
510 	rc = -EIO;
511 
512 return_zeroes:
513 	memset(dest, 0, efx->num_mac_stats * sizeof(u64));
514 	return rc;
515 }
516 
517 /**
518  * efx_nic_update_stats - Convert statistics DMA buffer to array of u64
519  * @desc: Array of &struct efx_hw_stat_desc describing the DMA buffer
520  *	layout.  DMA widths of 0, 16, 32 and 64 are supported; where
521  *	the width is specified as 0 the corresponding element of
522  *	@stats is not updated.
523  * @count: Length of the @desc array
524  * @mask: Bitmask of which elements of @desc are enabled
525  * @stats: Buffer to update with the converted statistics.  The length
526  *	of this array must be at least @count.
527  * @dma_buf: DMA buffer containing hardware statistics
528  * @accumulate: If set, the converted values will be added rather than
529  *	directly stored to the corresponding elements of @stats
530  */
531 void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count,
532 			  const unsigned long *mask,
533 			  u64 *stats, const void *dma_buf, bool accumulate)
534 {
535 	size_t index;
536 
537 	for_each_set_bit(index, mask, count) {
538 		if (desc[index].dma_width) {
539 			const void *addr = dma_buf + desc[index].offset;
540 			u64 val;
541 
542 			switch (desc[index].dma_width) {
543 			case 16:
544 				val = le16_to_cpup((__le16 *)addr);
545 				break;
546 			case 32:
547 				val = le32_to_cpup((__le32 *)addr);
548 				break;
549 			case 64:
550 				val = le64_to_cpup((__le64 *)addr);
551 				break;
552 			default:
553 				WARN_ON(1);
554 				val = 0;
555 				break;
556 			}
557 
558 			if (accumulate)
559 				stats[index] += val;
560 			else
561 				stats[index] = val;
562 		}
563 	}
564 }
565 
566 void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *rx_nodesc_drops)
567 {
568 	/* if down, or this is the first update after coming up */
569 	if (!(efx->net_dev->flags & IFF_UP) || !efx->rx_nodesc_drops_prev_state)
570 		efx->rx_nodesc_drops_while_down +=
571 			*rx_nodesc_drops - efx->rx_nodesc_drops_total;
572 	efx->rx_nodesc_drops_total = *rx_nodesc_drops;
573 	efx->rx_nodesc_drops_prev_state = !!(efx->net_dev->flags & IFF_UP);
574 	*rx_nodesc_drops -= efx->rx_nodesc_drops_while_down;
575 }
576