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v6.9.4
   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright(c) 2013 - 2019 Intel Corporation. */
   3
   4#include <linux/types.h>
   5#include <linux/module.h>
   6#include <net/ipv6.h>
   7#include <net/ip.h>
   8#include <net/tcp.h>
   9#include <linux/if_macvlan.h>
  10#include <linux/prefetch.h>
  11
  12#include "fm10k.h"
  13
  14#define DRV_SUMMARY	"Intel(R) Ethernet Switch Host Interface Driver"
  15char fm10k_driver_name[] = "fm10k";
  16static const char fm10k_driver_string[] = DRV_SUMMARY;
  17static const char fm10k_copyright[] =
  18	"Copyright(c) 2013 - 2019 Intel Corporation.";
  19
  20MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
  21MODULE_DESCRIPTION(DRV_SUMMARY);
  22MODULE_LICENSE("GPL v2");
  23
  24/* single workqueue for entire fm10k driver */
  25struct workqueue_struct *fm10k_workqueue;
  26
  27/**
  28 * fm10k_init_module - Driver Registration Routine
  29 *
  30 * fm10k_init_module is the first routine called when the driver is
  31 * loaded.  All it does is register with the PCI subsystem.
  32 **/
  33static int __init fm10k_init_module(void)
  34{
  35	int ret;
  36
  37	pr_info("%s\n", fm10k_driver_string);
  38	pr_info("%s\n", fm10k_copyright);
  39
  40	/* create driver workqueue */
  41	fm10k_workqueue = alloc_workqueue("%s", WQ_MEM_RECLAIM, 0,
  42					  fm10k_driver_name);
  43	if (!fm10k_workqueue)
  44		return -ENOMEM;
  45
  46	fm10k_dbg_init();
  47
  48	ret = fm10k_register_pci_driver();
  49	if (ret) {
  50		fm10k_dbg_exit();
  51		destroy_workqueue(fm10k_workqueue);
  52	}
  53
  54	return ret;
  55}
  56module_init(fm10k_init_module);
  57
  58/**
  59 * fm10k_exit_module - Driver Exit Cleanup Routine
  60 *
  61 * fm10k_exit_module is called just before the driver is removed
  62 * from memory.
  63 **/
  64static void __exit fm10k_exit_module(void)
  65{
  66	fm10k_unregister_pci_driver();
  67
  68	fm10k_dbg_exit();
  69
  70	/* destroy driver workqueue */
  71	destroy_workqueue(fm10k_workqueue);
  72}
  73module_exit(fm10k_exit_module);
  74
  75static bool fm10k_alloc_mapped_page(struct fm10k_ring *rx_ring,
  76				    struct fm10k_rx_buffer *bi)
  77{
  78	struct page *page = bi->page;
  79	dma_addr_t dma;
  80
  81	/* Only page will be NULL if buffer was consumed */
  82	if (likely(page))
  83		return true;
  84
  85	/* alloc new page for storage */
  86	page = dev_alloc_page();
  87	if (unlikely(!page)) {
  88		rx_ring->rx_stats.alloc_failed++;
  89		return false;
  90	}
  91
  92	/* map page for use */
  93	dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
  94
  95	/* if mapping failed free memory back to system since
  96	 * there isn't much point in holding memory we can't use
  97	 */
  98	if (dma_mapping_error(rx_ring->dev, dma)) {
  99		__free_page(page);
 100
 101		rx_ring->rx_stats.alloc_failed++;
 102		return false;
 103	}
 104
 105	bi->dma = dma;
 106	bi->page = page;
 107	bi->page_offset = 0;
 108
 109	return true;
 110}
 111
 112/**
 113 * fm10k_alloc_rx_buffers - Replace used receive buffers
 114 * @rx_ring: ring to place buffers on
 115 * @cleaned_count: number of buffers to replace
 116 **/
 117void fm10k_alloc_rx_buffers(struct fm10k_ring *rx_ring, u16 cleaned_count)
 118{
 119	union fm10k_rx_desc *rx_desc;
 120	struct fm10k_rx_buffer *bi;
 121	u16 i = rx_ring->next_to_use;
 122
 123	/* nothing to do */
 124	if (!cleaned_count)
 125		return;
 126
 127	rx_desc = FM10K_RX_DESC(rx_ring, i);
 128	bi = &rx_ring->rx_buffer[i];
 129	i -= rx_ring->count;
 130
 131	do {
 132		if (!fm10k_alloc_mapped_page(rx_ring, bi))
 133			break;
 134
 135		/* Refresh the desc even if buffer_addrs didn't change
 136		 * because each write-back erases this info.
 137		 */
 138		rx_desc->q.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);
 139
 140		rx_desc++;
 141		bi++;
 142		i++;
 143		if (unlikely(!i)) {
 144			rx_desc = FM10K_RX_DESC(rx_ring, 0);
 145			bi = rx_ring->rx_buffer;
 146			i -= rx_ring->count;
 147		}
 148
 149		/* clear the status bits for the next_to_use descriptor */
 150		rx_desc->d.staterr = 0;
 151
 152		cleaned_count--;
 153	} while (cleaned_count);
 154
 155	i += rx_ring->count;
 156
 157	if (rx_ring->next_to_use != i) {
 158		/* record the next descriptor to use */
 159		rx_ring->next_to_use = i;
 160
 161		/* update next to alloc since we have filled the ring */
 162		rx_ring->next_to_alloc = i;
 163
 164		/* Force memory writes to complete before letting h/w
 165		 * know there are new descriptors to fetch.  (Only
 166		 * applicable for weak-ordered memory model archs,
 167		 * such as IA-64).
 168		 */
 169		wmb();
 170
 171		/* notify hardware of new descriptors */
 172		writel(i, rx_ring->tail);
 173	}
 174}
 175
 176/**
 177 * fm10k_reuse_rx_page - page flip buffer and store it back on the ring
 178 * @rx_ring: rx descriptor ring to store buffers on
 179 * @old_buff: donor buffer to have page reused
 180 *
 181 * Synchronizes page for reuse by the interface
 182 **/
 183static void fm10k_reuse_rx_page(struct fm10k_ring *rx_ring,
 184				struct fm10k_rx_buffer *old_buff)
 185{
 186	struct fm10k_rx_buffer *new_buff;
 187	u16 nta = rx_ring->next_to_alloc;
 188
 189	new_buff = &rx_ring->rx_buffer[nta];
 190
 191	/* update, and store next to alloc */
 192	nta++;
 193	rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
 194
 195	/* transfer page from old buffer to new buffer */
 196	*new_buff = *old_buff;
 197
 198	/* sync the buffer for use by the device */
 199	dma_sync_single_range_for_device(rx_ring->dev, old_buff->dma,
 200					 old_buff->page_offset,
 201					 FM10K_RX_BUFSZ,
 202					 DMA_FROM_DEVICE);
 203}
 204
 205static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer,
 206				    struct page *page,
 207				    unsigned int __maybe_unused truesize)
 208{
 209	/* avoid re-using remote and pfmemalloc pages */
 210	if (!dev_page_is_reusable(page))
 211		return false;
 212
 213#if (PAGE_SIZE < 8192)
 214	/* if we are only owner of page we can reuse it */
 215	if (unlikely(page_count(page) != 1))
 216		return false;
 217
 218	/* flip page offset to other buffer */
 219	rx_buffer->page_offset ^= FM10K_RX_BUFSZ;
 220#else
 221	/* move offset up to the next cache line */
 222	rx_buffer->page_offset += truesize;
 223
 224	if (rx_buffer->page_offset > (PAGE_SIZE - FM10K_RX_BUFSZ))
 225		return false;
 226#endif
 227
 228	/* Even if we own the page, we are not allowed to use atomic_set()
 229	 * This would break get_page_unless_zero() users.
 230	 */
 231	page_ref_inc(page);
 232
 233	return true;
 234}
 235
 236/**
 237 * fm10k_add_rx_frag - Add contents of Rx buffer to sk_buff
 238 * @rx_buffer: buffer containing page to add
 239 * @size: packet size from rx_desc
 240 * @rx_desc: descriptor containing length of buffer written by hardware
 241 * @skb: sk_buff to place the data into
 242 *
 243 * This function will add the data contained in rx_buffer->page to the skb.
 244 * This is done either through a direct copy if the data in the buffer is
 245 * less than the skb header size, otherwise it will just attach the page as
 246 * a frag to the skb.
 247 *
 248 * The function will then update the page offset if necessary and return
 249 * true if the buffer can be reused by the interface.
 250 **/
 251static bool fm10k_add_rx_frag(struct fm10k_rx_buffer *rx_buffer,
 252			      unsigned int size,
 253			      union fm10k_rx_desc *rx_desc,
 254			      struct sk_buff *skb)
 255{
 256	struct page *page = rx_buffer->page;
 257	unsigned char *va = page_address(page) + rx_buffer->page_offset;
 258#if (PAGE_SIZE < 8192)
 259	unsigned int truesize = FM10K_RX_BUFSZ;
 260#else
 261	unsigned int truesize = ALIGN(size, 512);
 262#endif
 263	unsigned int pull_len;
 264
 265	if (unlikely(skb_is_nonlinear(skb)))
 266		goto add_tail_frag;
 267
 268	if (likely(size <= FM10K_RX_HDR_LEN)) {
 269		memcpy(__skb_put(skb, size), va, ALIGN(size, sizeof(long)));
 270
 271		/* page is reusable, we can reuse buffer as-is */
 272		if (dev_page_is_reusable(page))
 273			return true;
 274
 275		/* this page cannot be reused so discard it */
 276		__free_page(page);
 277		return false;
 278	}
 279
 280	/* we need the header to contain the greater of either ETH_HLEN or
 281	 * 60 bytes if the skb->len is less than 60 for skb_pad.
 282	 */
 283	pull_len = eth_get_headlen(skb->dev, va, FM10K_RX_HDR_LEN);
 284
 285	/* align pull length to size of long to optimize memcpy performance */
 286	memcpy(__skb_put(skb, pull_len), va, ALIGN(pull_len, sizeof(long)));
 287
 288	/* update all of the pointers */
 289	va += pull_len;
 290	size -= pull_len;
 291
 292add_tail_frag:
 293	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
 294			(unsigned long)va & ~PAGE_MASK, size, truesize);
 295
 296	return fm10k_can_reuse_rx_page(rx_buffer, page, truesize);
 297}
 298
 299static struct sk_buff *fm10k_fetch_rx_buffer(struct fm10k_ring *rx_ring,
 300					     union fm10k_rx_desc *rx_desc,
 301					     struct sk_buff *skb)
 302{
 303	unsigned int size = le16_to_cpu(rx_desc->w.length);
 304	struct fm10k_rx_buffer *rx_buffer;
 305	struct page *page;
 306
 307	rx_buffer = &rx_ring->rx_buffer[rx_ring->next_to_clean];
 308	page = rx_buffer->page;
 309	prefetchw(page);
 310
 311	if (likely(!skb)) {
 312		void *page_addr = page_address(page) +
 313				  rx_buffer->page_offset;
 314
 315		/* prefetch first cache line of first page */
 316		net_prefetch(page_addr);
 317
 318		/* allocate a skb to store the frags */
 319		skb = napi_alloc_skb(&rx_ring->q_vector->napi,
 320				     FM10K_RX_HDR_LEN);
 321		if (unlikely(!skb)) {
 322			rx_ring->rx_stats.alloc_failed++;
 323			return NULL;
 324		}
 325
 326		/* we will be copying header into skb->data in
 327		 * pskb_may_pull so it is in our interest to prefetch
 328		 * it now to avoid a possible cache miss
 329		 */
 330		prefetchw(skb->data);
 331	}
 332
 333	/* we are reusing so sync this buffer for CPU use */
 334	dma_sync_single_range_for_cpu(rx_ring->dev,
 335				      rx_buffer->dma,
 336				      rx_buffer->page_offset,
 337				      size,
 338				      DMA_FROM_DEVICE);
 339
 340	/* pull page into skb */
 341	if (fm10k_add_rx_frag(rx_buffer, size, rx_desc, skb)) {
 342		/* hand second half of page back to the ring */
 343		fm10k_reuse_rx_page(rx_ring, rx_buffer);
 344	} else {
 345		/* we are not reusing the buffer so unmap it */
 346		dma_unmap_page(rx_ring->dev, rx_buffer->dma,
 347			       PAGE_SIZE, DMA_FROM_DEVICE);
 348	}
 349
 350	/* clear contents of rx_buffer */
 351	rx_buffer->page = NULL;
 352
 353	return skb;
 354}
 355
 356static inline void fm10k_rx_checksum(struct fm10k_ring *ring,
 357				     union fm10k_rx_desc *rx_desc,
 358				     struct sk_buff *skb)
 359{
 360	skb_checksum_none_assert(skb);
 361
 362	/* Rx checksum disabled via ethtool */
 363	if (!(ring->netdev->features & NETIF_F_RXCSUM))
 364		return;
 365
 366	/* TCP/UDP checksum error bit is set */
 367	if (fm10k_test_staterr(rx_desc,
 368			       FM10K_RXD_STATUS_L4E |
 369			       FM10K_RXD_STATUS_L4E2 |
 370			       FM10K_RXD_STATUS_IPE |
 371			       FM10K_RXD_STATUS_IPE2)) {
 372		ring->rx_stats.csum_err++;
 373		return;
 374	}
 375
 376	/* It must be a TCP or UDP packet with a valid checksum */
 377	if (fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_L4CS2))
 378		skb->encapsulation = true;
 379	else if (!fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_L4CS))
 380		return;
 381
 382	skb->ip_summed = CHECKSUM_UNNECESSARY;
 383
 384	ring->rx_stats.csum_good++;
 385}
 386
 387#define FM10K_RSS_L4_TYPES_MASK \
 388	(BIT(FM10K_RSSTYPE_IPV4_TCP) | \
 389	 BIT(FM10K_RSSTYPE_IPV4_UDP) | \
 390	 BIT(FM10K_RSSTYPE_IPV6_TCP) | \
 391	 BIT(FM10K_RSSTYPE_IPV6_UDP))
 392
 393static inline void fm10k_rx_hash(struct fm10k_ring *ring,
 394				 union fm10k_rx_desc *rx_desc,
 395				 struct sk_buff *skb)
 396{
 397	u16 rss_type;
 398
 399	if (!(ring->netdev->features & NETIF_F_RXHASH))
 400		return;
 401
 402	rss_type = le16_to_cpu(rx_desc->w.pkt_info) & FM10K_RXD_RSSTYPE_MASK;
 403	if (!rss_type)
 404		return;
 405
 406	skb_set_hash(skb, le32_to_cpu(rx_desc->d.rss),
 407		     (BIT(rss_type) & FM10K_RSS_L4_TYPES_MASK) ?
 408		     PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3);
 409}
 410
 411static void fm10k_type_trans(struct fm10k_ring *rx_ring,
 412			     union fm10k_rx_desc __maybe_unused *rx_desc,
 413			     struct sk_buff *skb)
 414{
 415	struct net_device *dev = rx_ring->netdev;
 416	struct fm10k_l2_accel *l2_accel = rcu_dereference_bh(rx_ring->l2_accel);
 417
 418	/* check to see if DGLORT belongs to a MACVLAN */
 419	if (l2_accel) {
 420		u16 idx = le16_to_cpu(FM10K_CB(skb)->fi.w.dglort) - 1;
 421
 422		idx -= l2_accel->dglort;
 423		if (idx < l2_accel->size && l2_accel->macvlan[idx])
 424			dev = l2_accel->macvlan[idx];
 425		else
 426			l2_accel = NULL;
 427	}
 428
 429	/* Record Rx queue, or update macvlan statistics */
 430	if (!l2_accel)
 431		skb_record_rx_queue(skb, rx_ring->queue_index);
 432	else
 433		macvlan_count_rx(netdev_priv(dev), skb->len + ETH_HLEN, true,
 434				 false);
 435
 436	skb->protocol = eth_type_trans(skb, dev);
 437}
 438
 439/**
 440 * fm10k_process_skb_fields - Populate skb header fields from Rx descriptor
 441 * @rx_ring: rx descriptor ring packet is being transacted on
 442 * @rx_desc: pointer to the EOP Rx descriptor
 443 * @skb: pointer to current skb being populated
 444 *
 445 * This function checks the ring, descriptor, and packet information in
 446 * order to populate the hash, checksum, VLAN, timestamp, protocol, and
 447 * other fields within the skb.
 448 **/
 449static unsigned int fm10k_process_skb_fields(struct fm10k_ring *rx_ring,
 450					     union fm10k_rx_desc *rx_desc,
 451					     struct sk_buff *skb)
 452{
 453	unsigned int len = skb->len;
 454
 455	fm10k_rx_hash(rx_ring, rx_desc, skb);
 456
 457	fm10k_rx_checksum(rx_ring, rx_desc, skb);
 458
 459	FM10K_CB(skb)->tstamp = rx_desc->q.timestamp;
 460
 461	FM10K_CB(skb)->fi.w.vlan = rx_desc->w.vlan;
 462
 463	FM10K_CB(skb)->fi.d.glort = rx_desc->d.glort;
 464
 465	if (rx_desc->w.vlan) {
 466		u16 vid = le16_to_cpu(rx_desc->w.vlan);
 467
 468		if ((vid & VLAN_VID_MASK) != rx_ring->vid)
 469			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vid);
 470		else if (vid & VLAN_PRIO_MASK)
 471			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 472					       vid & VLAN_PRIO_MASK);
 473	}
 474
 475	fm10k_type_trans(rx_ring, rx_desc, skb);
 476
 477	return len;
 478}
 479
 480/**
 481 * fm10k_is_non_eop - process handling of non-EOP buffers
 482 * @rx_ring: Rx ring being processed
 483 * @rx_desc: Rx descriptor for current buffer
 484 *
 485 * This function updates next to clean.  If the buffer is an EOP buffer
 486 * this function exits returning false, otherwise it will place the
 487 * sk_buff in the next buffer to be chained and return true indicating
 488 * that this is in fact a non-EOP buffer.
 489 **/
 490static bool fm10k_is_non_eop(struct fm10k_ring *rx_ring,
 491			     union fm10k_rx_desc *rx_desc)
 492{
 493	u32 ntc = rx_ring->next_to_clean + 1;
 494
 495	/* fetch, update, and store next to clean */
 496	ntc = (ntc < rx_ring->count) ? ntc : 0;
 497	rx_ring->next_to_clean = ntc;
 498
 499	prefetch(FM10K_RX_DESC(rx_ring, ntc));
 500
 501	if (likely(fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_EOP)))
 502		return false;
 503
 504	return true;
 505}
 506
 507/**
 508 * fm10k_cleanup_headers - Correct corrupted or empty headers
 509 * @rx_ring: rx descriptor ring packet is being transacted on
 510 * @rx_desc: pointer to the EOP Rx descriptor
 511 * @skb: pointer to current skb being fixed
 512 *
 513 * Address the case where we are pulling data in on pages only
 514 * and as such no data is present in the skb header.
 515 *
 516 * In addition if skb is not at least 60 bytes we need to pad it so that
 517 * it is large enough to qualify as a valid Ethernet frame.
 518 *
 519 * Returns true if an error was encountered and skb was freed.
 520 **/
 521static bool fm10k_cleanup_headers(struct fm10k_ring *rx_ring,
 522				  union fm10k_rx_desc *rx_desc,
 523				  struct sk_buff *skb)
 524{
 525	if (unlikely((fm10k_test_staterr(rx_desc,
 526					 FM10K_RXD_STATUS_RXE)))) {
 527#define FM10K_TEST_RXD_BIT(rxd, bit) \
 528	((rxd)->w.csum_err & cpu_to_le16(bit))
 529		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_SWITCH_ERROR))
 530			rx_ring->rx_stats.switch_errors++;
 531		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_NO_DESCRIPTOR))
 532			rx_ring->rx_stats.drops++;
 533		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_PP_ERROR))
 534			rx_ring->rx_stats.pp_errors++;
 535		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_SWITCH_READY))
 536			rx_ring->rx_stats.link_errors++;
 537		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_TOO_BIG))
 538			rx_ring->rx_stats.length_errors++;
 539		dev_kfree_skb_any(skb);
 540		rx_ring->rx_stats.errors++;
 541		return true;
 542	}
 543
 544	/* if eth_skb_pad returns an error the skb was freed */
 545	if (eth_skb_pad(skb))
 546		return true;
 547
 548	return false;
 549}
 550
 551/**
 552 * fm10k_receive_skb - helper function to handle rx indications
 553 * @q_vector: structure containing interrupt and ring information
 554 * @skb: packet to send up
 555 **/
 556static void fm10k_receive_skb(struct fm10k_q_vector *q_vector,
 557			      struct sk_buff *skb)
 558{
 559	napi_gro_receive(&q_vector->napi, skb);
 560}
 561
 562static int fm10k_clean_rx_irq(struct fm10k_q_vector *q_vector,
 563			      struct fm10k_ring *rx_ring,
 564			      int budget)
 565{
 566	struct sk_buff *skb = rx_ring->skb;
 567	unsigned int total_bytes = 0, total_packets = 0;
 568	u16 cleaned_count = fm10k_desc_unused(rx_ring);
 569
 570	while (likely(total_packets < budget)) {
 571		union fm10k_rx_desc *rx_desc;
 572
 573		/* return some buffers to hardware, one at a time is too slow */
 574		if (cleaned_count >= FM10K_RX_BUFFER_WRITE) {
 575			fm10k_alloc_rx_buffers(rx_ring, cleaned_count);
 576			cleaned_count = 0;
 577		}
 578
 579		rx_desc = FM10K_RX_DESC(rx_ring, rx_ring->next_to_clean);
 580
 581		if (!rx_desc->d.staterr)
 582			break;
 583
 584		/* This memory barrier is needed to keep us from reading
 585		 * any other fields out of the rx_desc until we know the
 586		 * descriptor has been written back
 587		 */
 588		dma_rmb();
 589
 590		/* retrieve a buffer from the ring */
 591		skb = fm10k_fetch_rx_buffer(rx_ring, rx_desc, skb);
 592
 593		/* exit if we failed to retrieve a buffer */
 594		if (!skb)
 595			break;
 596
 597		cleaned_count++;
 598
 599		/* fetch next buffer in frame if non-eop */
 600		if (fm10k_is_non_eop(rx_ring, rx_desc))
 601			continue;
 602
 603		/* verify the packet layout is correct */
 604		if (fm10k_cleanup_headers(rx_ring, rx_desc, skb)) {
 605			skb = NULL;
 606			continue;
 607		}
 608
 609		/* populate checksum, timestamp, VLAN, and protocol */
 610		total_bytes += fm10k_process_skb_fields(rx_ring, rx_desc, skb);
 611
 612		fm10k_receive_skb(q_vector, skb);
 613
 614		/* reset skb pointer */
 615		skb = NULL;
 616
 617		/* update budget accounting */
 618		total_packets++;
 619	}
 620
 621	/* place incomplete frames back on ring for completion */
 622	rx_ring->skb = skb;
 623
 624	u64_stats_update_begin(&rx_ring->syncp);
 625	rx_ring->stats.packets += total_packets;
 626	rx_ring->stats.bytes += total_bytes;
 627	u64_stats_update_end(&rx_ring->syncp);
 628	q_vector->rx.total_packets += total_packets;
 629	q_vector->rx.total_bytes += total_bytes;
 630
 631	return total_packets;
 632}
 633
 634#define VXLAN_HLEN (sizeof(struct udphdr) + 8)
 635static struct ethhdr *fm10k_port_is_vxlan(struct sk_buff *skb)
 636{
 637	struct fm10k_intfc *interface = netdev_priv(skb->dev);
 638
 639	if (interface->vxlan_port != udp_hdr(skb)->dest)
 640		return NULL;
 641
 642	/* return offset of udp_hdr plus 8 bytes for VXLAN header */
 643	return (struct ethhdr *)(skb_transport_header(skb) + VXLAN_HLEN);
 644}
 645
 646#define FM10K_NVGRE_RESERVED0_FLAGS htons(0x9FFF)
 647#define NVGRE_TNI htons(0x2000)
 648struct fm10k_nvgre_hdr {
 649	__be16 flags;
 650	__be16 proto;
 651	__be32 tni;
 652};
 653
 654static struct ethhdr *fm10k_gre_is_nvgre(struct sk_buff *skb)
 655{
 656	struct fm10k_nvgre_hdr *nvgre_hdr;
 657	int hlen = ip_hdrlen(skb);
 658
 659	/* currently only IPv4 is supported due to hlen above */
 660	if (vlan_get_protocol(skb) != htons(ETH_P_IP))
 661		return NULL;
 662
 663	/* our transport header should be NVGRE */
 664	nvgre_hdr = (struct fm10k_nvgre_hdr *)(skb_network_header(skb) + hlen);
 665
 666	/* verify all reserved flags are 0 */
 667	if (nvgre_hdr->flags & FM10K_NVGRE_RESERVED0_FLAGS)
 668		return NULL;
 669
 670	/* report start of ethernet header */
 671	if (nvgre_hdr->flags & NVGRE_TNI)
 672		return (struct ethhdr *)(nvgre_hdr + 1);
 673
 674	return (struct ethhdr *)(&nvgre_hdr->tni);
 675}
 676
 677__be16 fm10k_tx_encap_offload(struct sk_buff *skb)
 678{
 679	u8 l4_hdr = 0, inner_l4_hdr = 0, inner_l4_hlen;
 680	struct ethhdr *eth_hdr;
 681
 682	if (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 683	    skb->inner_protocol != htons(ETH_P_TEB))
 684		return 0;
 685
 686	switch (vlan_get_protocol(skb)) {
 687	case htons(ETH_P_IP):
 688		l4_hdr = ip_hdr(skb)->protocol;
 689		break;
 690	case htons(ETH_P_IPV6):
 691		l4_hdr = ipv6_hdr(skb)->nexthdr;
 692		break;
 693	default:
 694		return 0;
 695	}
 696
 697	switch (l4_hdr) {
 698	case IPPROTO_UDP:
 699		eth_hdr = fm10k_port_is_vxlan(skb);
 700		break;
 701	case IPPROTO_GRE:
 702		eth_hdr = fm10k_gre_is_nvgre(skb);
 703		break;
 704	default:
 705		return 0;
 706	}
 707
 708	if (!eth_hdr)
 709		return 0;
 710
 711	switch (eth_hdr->h_proto) {
 712	case htons(ETH_P_IP):
 713		inner_l4_hdr = inner_ip_hdr(skb)->protocol;
 714		break;
 715	case htons(ETH_P_IPV6):
 716		inner_l4_hdr = inner_ipv6_hdr(skb)->nexthdr;
 717		break;
 718	default:
 719		return 0;
 720	}
 721
 722	switch (inner_l4_hdr) {
 723	case IPPROTO_TCP:
 724		inner_l4_hlen = inner_tcp_hdrlen(skb);
 725		break;
 726	case IPPROTO_UDP:
 727		inner_l4_hlen = 8;
 728		break;
 729	default:
 730		return 0;
 731	}
 732
 733	/* The hardware allows tunnel offloads only if the combined inner and
 734	 * outer header is 184 bytes or less
 735	 */
 736	if (skb_inner_transport_header(skb) + inner_l4_hlen -
 737	    skb_mac_header(skb) > FM10K_TUNNEL_HEADER_LENGTH)
 738		return 0;
 739
 740	return eth_hdr->h_proto;
 741}
 742
 743static int fm10k_tso(struct fm10k_ring *tx_ring,
 744		     struct fm10k_tx_buffer *first)
 745{
 746	struct sk_buff *skb = first->skb;
 747	struct fm10k_tx_desc *tx_desc;
 748	unsigned char *th;
 749	u8 hdrlen;
 750
 751	if (skb->ip_summed != CHECKSUM_PARTIAL)
 752		return 0;
 753
 754	if (!skb_is_gso(skb))
 755		return 0;
 756
 757	/* compute header lengths */
 758	if (skb->encapsulation) {
 759		if (!fm10k_tx_encap_offload(skb))
 760			goto err_vxlan;
 761		th = skb_inner_transport_header(skb);
 762	} else {
 763		th = skb_transport_header(skb);
 764	}
 765
 766	/* compute offset from SOF to transport header and add header len */
 767	hdrlen = (th - skb->data) + (((struct tcphdr *)th)->doff << 2);
 768
 769	first->tx_flags |= FM10K_TX_FLAGS_CSUM;
 770
 771	/* update gso size and bytecount with header size */
 772	first->gso_segs = skb_shinfo(skb)->gso_segs;
 773	first->bytecount += (first->gso_segs - 1) * hdrlen;
 774
 775	/* populate Tx descriptor header size and mss */
 776	tx_desc = FM10K_TX_DESC(tx_ring, tx_ring->next_to_use);
 777	tx_desc->hdrlen = hdrlen;
 778	tx_desc->mss = cpu_to_le16(skb_shinfo(skb)->gso_size);
 779
 780	return 1;
 781
 782err_vxlan:
 783	tx_ring->netdev->features &= ~NETIF_F_GSO_UDP_TUNNEL;
 784	if (net_ratelimit())
 785		netdev_err(tx_ring->netdev,
 786			   "TSO requested for unsupported tunnel, disabling offload\n");
 787	return -1;
 788}
 789
 790static void fm10k_tx_csum(struct fm10k_ring *tx_ring,
 791			  struct fm10k_tx_buffer *first)
 792{
 793	struct sk_buff *skb = first->skb;
 794	struct fm10k_tx_desc *tx_desc;
 795	union {
 796		struct iphdr *ipv4;
 797		struct ipv6hdr *ipv6;
 798		u8 *raw;
 799	} network_hdr;
 800	u8 *transport_hdr;
 801	__be16 frag_off;
 802	__be16 protocol;
 803	u8 l4_hdr = 0;
 804
 805	if (skb->ip_summed != CHECKSUM_PARTIAL)
 806		goto no_csum;
 807
 808	if (skb->encapsulation) {
 809		protocol = fm10k_tx_encap_offload(skb);
 810		if (!protocol) {
 811			if (skb_checksum_help(skb)) {
 812				dev_warn(tx_ring->dev,
 813					 "failed to offload encap csum!\n");
 814				tx_ring->tx_stats.csum_err++;
 815			}
 816			goto no_csum;
 817		}
 818		network_hdr.raw = skb_inner_network_header(skb);
 819		transport_hdr = skb_inner_transport_header(skb);
 820	} else {
 821		protocol = vlan_get_protocol(skb);
 822		network_hdr.raw = skb_network_header(skb);
 823		transport_hdr = skb_transport_header(skb);
 824	}
 825
 826	switch (protocol) {
 827	case htons(ETH_P_IP):
 828		l4_hdr = network_hdr.ipv4->protocol;
 829		break;
 830	case htons(ETH_P_IPV6):
 831		l4_hdr = network_hdr.ipv6->nexthdr;
 832		if (likely((transport_hdr - network_hdr.raw) ==
 833			   sizeof(struct ipv6hdr)))
 834			break;
 835		ipv6_skip_exthdr(skb, network_hdr.raw - skb->data +
 836				      sizeof(struct ipv6hdr),
 837				 &l4_hdr, &frag_off);
 838		if (unlikely(frag_off))
 839			l4_hdr = NEXTHDR_FRAGMENT;
 840		break;
 841	default:
 842		break;
 843	}
 844
 845	switch (l4_hdr) {
 846	case IPPROTO_TCP:
 847	case IPPROTO_UDP:
 848		break;
 849	case IPPROTO_GRE:
 850		if (skb->encapsulation)
 851			break;
 852		fallthrough;
 853	default:
 854		if (unlikely(net_ratelimit())) {
 855			dev_warn(tx_ring->dev,
 856				 "partial checksum, version=%d l4 proto=%x\n",
 857				 protocol, l4_hdr);
 858		}
 859		skb_checksum_help(skb);
 860		tx_ring->tx_stats.csum_err++;
 861		goto no_csum;
 862	}
 863
 864	/* update TX checksum flag */
 865	first->tx_flags |= FM10K_TX_FLAGS_CSUM;
 866	tx_ring->tx_stats.csum_good++;
 867
 868no_csum:
 869	/* populate Tx descriptor header size and mss */
 870	tx_desc = FM10K_TX_DESC(tx_ring, tx_ring->next_to_use);
 871	tx_desc->hdrlen = 0;
 872	tx_desc->mss = 0;
 873}
 874
 875#define FM10K_SET_FLAG(_input, _flag, _result) \
 876	((_flag <= _result) ? \
 877	 ((u32)(_input & _flag) * (_result / _flag)) : \
 878	 ((u32)(_input & _flag) / (_flag / _result)))
 879
 880static u8 fm10k_tx_desc_flags(struct sk_buff *skb, u32 tx_flags)
 881{
 882	/* set type for advanced descriptor with frame checksum insertion */
 883	u32 desc_flags = 0;
 884
 885	/* set checksum offload bits */
 886	desc_flags |= FM10K_SET_FLAG(tx_flags, FM10K_TX_FLAGS_CSUM,
 887				     FM10K_TXD_FLAG_CSUM);
 888
 889	return desc_flags;
 890}
 891
 892static bool fm10k_tx_desc_push(struct fm10k_ring *tx_ring,
 893			       struct fm10k_tx_desc *tx_desc, u16 i,
 894			       dma_addr_t dma, unsigned int size, u8 desc_flags)
 895{
 896	/* set RS and INT for last frame in a cache line */
 897	if ((++i & (FM10K_TXD_WB_FIFO_SIZE - 1)) == 0)
 898		desc_flags |= FM10K_TXD_FLAG_RS | FM10K_TXD_FLAG_INT;
 899
 900	/* record values to descriptor */
 901	tx_desc->buffer_addr = cpu_to_le64(dma);
 902	tx_desc->flags = desc_flags;
 903	tx_desc->buflen = cpu_to_le16(size);
 904
 905	/* return true if we just wrapped the ring */
 906	return i == tx_ring->count;
 907}
 908
 909static int __fm10k_maybe_stop_tx(struct fm10k_ring *tx_ring, u16 size)
 910{
 911	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
 912
 913	/* Memory barrier before checking head and tail */
 914	smp_mb();
 915
 916	/* Check again in a case another CPU has just made room available */
 917	if (likely(fm10k_desc_unused(tx_ring) < size))
 918		return -EBUSY;
 919
 920	/* A reprieve! - use start_queue because it doesn't call schedule */
 921	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
 922	++tx_ring->tx_stats.restart_queue;
 923	return 0;
 924}
 925
 926static inline int fm10k_maybe_stop_tx(struct fm10k_ring *tx_ring, u16 size)
 927{
 928	if (likely(fm10k_desc_unused(tx_ring) >= size))
 929		return 0;
 930	return __fm10k_maybe_stop_tx(tx_ring, size);
 931}
 932
 933static void fm10k_tx_map(struct fm10k_ring *tx_ring,
 934			 struct fm10k_tx_buffer *first)
 935{
 936	struct sk_buff *skb = first->skb;
 937	struct fm10k_tx_buffer *tx_buffer;
 938	struct fm10k_tx_desc *tx_desc;
 939	skb_frag_t *frag;
 940	unsigned char *data;
 941	dma_addr_t dma;
 942	unsigned int data_len, size;
 943	u32 tx_flags = first->tx_flags;
 944	u16 i = tx_ring->next_to_use;
 945	u8 flags = fm10k_tx_desc_flags(skb, tx_flags);
 946
 947	tx_desc = FM10K_TX_DESC(tx_ring, i);
 948
 949	/* add HW VLAN tag */
 950	if (skb_vlan_tag_present(skb))
 951		tx_desc->vlan = cpu_to_le16(skb_vlan_tag_get(skb));
 952	else
 953		tx_desc->vlan = 0;
 954
 955	size = skb_headlen(skb);
 956	data = skb->data;
 957
 958	dma = dma_map_single(tx_ring->dev, data, size, DMA_TO_DEVICE);
 959
 960	data_len = skb->data_len;
 961	tx_buffer = first;
 962
 963	for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
 964		if (dma_mapping_error(tx_ring->dev, dma))
 965			goto dma_error;
 966
 967		/* record length, and DMA address */
 968		dma_unmap_len_set(tx_buffer, len, size);
 969		dma_unmap_addr_set(tx_buffer, dma, dma);
 970
 971		while (unlikely(size > FM10K_MAX_DATA_PER_TXD)) {
 972			if (fm10k_tx_desc_push(tx_ring, tx_desc++, i++, dma,
 973					       FM10K_MAX_DATA_PER_TXD, flags)) {
 974				tx_desc = FM10K_TX_DESC(tx_ring, 0);
 975				i = 0;
 976			}
 977
 978			dma += FM10K_MAX_DATA_PER_TXD;
 979			size -= FM10K_MAX_DATA_PER_TXD;
 980		}
 981
 982		if (likely(!data_len))
 983			break;
 984
 985		if (fm10k_tx_desc_push(tx_ring, tx_desc++, i++,
 986				       dma, size, flags)) {
 987			tx_desc = FM10K_TX_DESC(tx_ring, 0);
 988			i = 0;
 989		}
 990
 991		size = skb_frag_size(frag);
 992		data_len -= size;
 993
 994		dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
 995				       DMA_TO_DEVICE);
 996
 997		tx_buffer = &tx_ring->tx_buffer[i];
 998	}
 999
1000	/* write last descriptor with LAST bit set */
1001	flags |= FM10K_TXD_FLAG_LAST;
1002
1003	if (fm10k_tx_desc_push(tx_ring, tx_desc, i++, dma, size, flags))
1004		i = 0;
1005
1006	/* record bytecount for BQL */
1007	netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);
1008
1009	/* record SW timestamp if HW timestamp is not available */
1010	skb_tx_timestamp(first->skb);
1011
1012	/* Force memory writes to complete before letting h/w know there
1013	 * are new descriptors to fetch.  (Only applicable for weak-ordered
1014	 * memory model archs, such as IA-64).
1015	 *
1016	 * We also need this memory barrier to make certain all of the
1017	 * status bits have been updated before next_to_watch is written.
1018	 */
1019	wmb();
1020
1021	/* set next_to_watch value indicating a packet is present */
1022	first->next_to_watch = tx_desc;
1023
1024	tx_ring->next_to_use = i;
1025
1026	/* Make sure there is space in the ring for the next send. */
1027	fm10k_maybe_stop_tx(tx_ring, DESC_NEEDED);
1028
1029	/* notify HW of packet */
1030	if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) {
1031		writel(i, tx_ring->tail);
1032	}
1033
1034	return;
1035dma_error:
1036	dev_err(tx_ring->dev, "TX DMA map failed\n");
1037
1038	/* clear dma mappings for failed tx_buffer map */
1039	for (;;) {
1040		tx_buffer = &tx_ring->tx_buffer[i];
1041		fm10k_unmap_and_free_tx_resource(tx_ring, tx_buffer);
1042		if (tx_buffer == first)
1043			break;
1044		if (i == 0)
1045			i = tx_ring->count;
1046		i--;
1047	}
1048
1049	tx_ring->next_to_use = i;
1050}
1051
1052netdev_tx_t fm10k_xmit_frame_ring(struct sk_buff *skb,
1053				  struct fm10k_ring *tx_ring)
1054{
1055	u16 count = TXD_USE_COUNT(skb_headlen(skb));
1056	struct fm10k_tx_buffer *first;
1057	unsigned short f;
1058	u32 tx_flags = 0;
1059	int tso;
1060
1061	/* need: 1 descriptor per page * PAGE_SIZE/FM10K_MAX_DATA_PER_TXD,
1062	 *       + 1 desc for skb_headlen/FM10K_MAX_DATA_PER_TXD,
1063	 *       + 2 desc gap to keep tail from touching head
1064	 * otherwise try next time
1065	 */
1066	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
1067		skb_frag_t *frag = &skb_shinfo(skb)->frags[f];
1068
1069		count += TXD_USE_COUNT(skb_frag_size(frag));
1070	}
1071
1072	if (fm10k_maybe_stop_tx(tx_ring, count + 3)) {
1073		tx_ring->tx_stats.tx_busy++;
1074		return NETDEV_TX_BUSY;
1075	}
1076
1077	/* record the location of the first descriptor for this packet */
1078	first = &tx_ring->tx_buffer[tx_ring->next_to_use];
1079	first->skb = skb;
1080	first->bytecount = max_t(unsigned int, skb->len, ETH_ZLEN);
1081	first->gso_segs = 1;
1082
1083	/* record initial flags and protocol */
1084	first->tx_flags = tx_flags;
1085
1086	tso = fm10k_tso(tx_ring, first);
1087	if (tso < 0)
1088		goto out_drop;
1089	else if (!tso)
1090		fm10k_tx_csum(tx_ring, first);
1091
1092	fm10k_tx_map(tx_ring, first);
1093
1094	return NETDEV_TX_OK;
1095
1096out_drop:
1097	dev_kfree_skb_any(first->skb);
1098	first->skb = NULL;
1099
1100	return NETDEV_TX_OK;
1101}
1102
1103static u64 fm10k_get_tx_completed(struct fm10k_ring *ring)
1104{
1105	return ring->stats.packets;
1106}
1107
1108/**
1109 * fm10k_get_tx_pending - how many Tx descriptors not processed
1110 * @ring: the ring structure
1111 * @in_sw: is tx_pending being checked in SW or in HW?
1112 */
1113u64 fm10k_get_tx_pending(struct fm10k_ring *ring, bool in_sw)
1114{
1115	struct fm10k_intfc *interface = ring->q_vector->interface;
1116	struct fm10k_hw *hw = &interface->hw;
1117	u32 head, tail;
1118
1119	if (likely(in_sw)) {
1120		head = ring->next_to_clean;
1121		tail = ring->next_to_use;
1122	} else {
1123		head = fm10k_read_reg(hw, FM10K_TDH(ring->reg_idx));
1124		tail = fm10k_read_reg(hw, FM10K_TDT(ring->reg_idx));
1125	}
1126
1127	return ((head <= tail) ? tail : tail + ring->count) - head;
1128}
1129
1130bool fm10k_check_tx_hang(struct fm10k_ring *tx_ring)
1131{
1132	u32 tx_done = fm10k_get_tx_completed(tx_ring);
1133	u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
1134	u32 tx_pending = fm10k_get_tx_pending(tx_ring, true);
1135
1136	clear_check_for_tx_hang(tx_ring);
1137
1138	/* Check for a hung queue, but be thorough. This verifies
1139	 * that a transmit has been completed since the previous
1140	 * check AND there is at least one packet pending. By
1141	 * requiring this to fail twice we avoid races with
1142	 * clearing the ARMED bit and conditions where we
1143	 * run the check_tx_hang logic with a transmit completion
1144	 * pending but without time to complete it yet.
1145	 */
1146	if (!tx_pending || (tx_done_old != tx_done)) {
1147		/* update completed stats and continue */
1148		tx_ring->tx_stats.tx_done_old = tx_done;
1149		/* reset the countdown */
1150		clear_bit(__FM10K_HANG_CHECK_ARMED, tx_ring->state);
1151
1152		return false;
1153	}
1154
1155	/* make sure it is true for two checks in a row */
1156	return test_and_set_bit(__FM10K_HANG_CHECK_ARMED, tx_ring->state);
1157}
1158
1159/**
1160 * fm10k_tx_timeout_reset - initiate reset due to Tx timeout
1161 * @interface: driver private struct
1162 **/
1163void fm10k_tx_timeout_reset(struct fm10k_intfc *interface)
1164{
1165	/* Do the reset outside of interrupt context */
1166	if (!test_bit(__FM10K_DOWN, interface->state)) {
1167		interface->tx_timeout_count++;
1168		set_bit(FM10K_FLAG_RESET_REQUESTED, interface->flags);
1169		fm10k_service_event_schedule(interface);
1170	}
1171}
1172
1173/**
1174 * fm10k_clean_tx_irq - Reclaim resources after transmit completes
1175 * @q_vector: structure containing interrupt and ring information
1176 * @tx_ring: tx ring to clean
1177 * @napi_budget: Used to determine if we are in netpoll
1178 **/
1179static bool fm10k_clean_tx_irq(struct fm10k_q_vector *q_vector,
1180			       struct fm10k_ring *tx_ring, int napi_budget)
1181{
1182	struct fm10k_intfc *interface = q_vector->interface;
1183	struct fm10k_tx_buffer *tx_buffer;
1184	struct fm10k_tx_desc *tx_desc;
1185	unsigned int total_bytes = 0, total_packets = 0;
1186	unsigned int budget = q_vector->tx.work_limit;
1187	unsigned int i = tx_ring->next_to_clean;
1188
1189	if (test_bit(__FM10K_DOWN, interface->state))
1190		return true;
1191
1192	tx_buffer = &tx_ring->tx_buffer[i];
1193	tx_desc = FM10K_TX_DESC(tx_ring, i);
1194	i -= tx_ring->count;
1195
1196	do {
1197		struct fm10k_tx_desc *eop_desc = tx_buffer->next_to_watch;
1198
1199		/* if next_to_watch is not set then there is no work pending */
1200		if (!eop_desc)
1201			break;
1202
1203		/* prevent any other reads prior to eop_desc */
1204		smp_rmb();
1205
1206		/* if DD is not set pending work has not been completed */
1207		if (!(eop_desc->flags & FM10K_TXD_FLAG_DONE))
1208			break;
1209
1210		/* clear next_to_watch to prevent false hangs */
1211		tx_buffer->next_to_watch = NULL;
1212
1213		/* update the statistics for this packet */
1214		total_bytes += tx_buffer->bytecount;
1215		total_packets += tx_buffer->gso_segs;
1216
1217		/* free the skb */
1218		napi_consume_skb(tx_buffer->skb, napi_budget);
1219
1220		/* unmap skb header data */
1221		dma_unmap_single(tx_ring->dev,
1222				 dma_unmap_addr(tx_buffer, dma),
1223				 dma_unmap_len(tx_buffer, len),
1224				 DMA_TO_DEVICE);
1225
1226		/* clear tx_buffer data */
1227		tx_buffer->skb = NULL;
1228		dma_unmap_len_set(tx_buffer, len, 0);
1229
1230		/* unmap remaining buffers */
1231		while (tx_desc != eop_desc) {
1232			tx_buffer++;
1233			tx_desc++;
1234			i++;
1235			if (unlikely(!i)) {
1236				i -= tx_ring->count;
1237				tx_buffer = tx_ring->tx_buffer;
1238				tx_desc = FM10K_TX_DESC(tx_ring, 0);
1239			}
1240
1241			/* unmap any remaining paged data */
1242			if (dma_unmap_len(tx_buffer, len)) {
1243				dma_unmap_page(tx_ring->dev,
1244					       dma_unmap_addr(tx_buffer, dma),
1245					       dma_unmap_len(tx_buffer, len),
1246					       DMA_TO_DEVICE);
1247				dma_unmap_len_set(tx_buffer, len, 0);
1248			}
1249		}
1250
1251		/* move us one more past the eop_desc for start of next pkt */
1252		tx_buffer++;
1253		tx_desc++;
1254		i++;
1255		if (unlikely(!i)) {
1256			i -= tx_ring->count;
1257			tx_buffer = tx_ring->tx_buffer;
1258			tx_desc = FM10K_TX_DESC(tx_ring, 0);
1259		}
1260
1261		/* issue prefetch for next Tx descriptor */
1262		prefetch(tx_desc);
1263
1264		/* update budget accounting */
1265		budget--;
1266	} while (likely(budget));
1267
1268	i += tx_ring->count;
1269	tx_ring->next_to_clean = i;
1270	u64_stats_update_begin(&tx_ring->syncp);
1271	tx_ring->stats.bytes += total_bytes;
1272	tx_ring->stats.packets += total_packets;
1273	u64_stats_update_end(&tx_ring->syncp);
1274	q_vector->tx.total_bytes += total_bytes;
1275	q_vector->tx.total_packets += total_packets;
1276
1277	if (check_for_tx_hang(tx_ring) && fm10k_check_tx_hang(tx_ring)) {
1278		/* schedule immediate reset if we believe we hung */
1279		struct fm10k_hw *hw = &interface->hw;
1280
1281		netif_err(interface, drv, tx_ring->netdev,
1282			  "Detected Tx Unit Hang\n"
1283			  "  Tx Queue             <%d>\n"
1284			  "  TDH, TDT             <%x>, <%x>\n"
1285			  "  next_to_use          <%x>\n"
1286			  "  next_to_clean        <%x>\n",
1287			  tx_ring->queue_index,
1288			  fm10k_read_reg(hw, FM10K_TDH(tx_ring->reg_idx)),
1289			  fm10k_read_reg(hw, FM10K_TDT(tx_ring->reg_idx)),
1290			  tx_ring->next_to_use, i);
1291
1292		netif_stop_subqueue(tx_ring->netdev,
1293				    tx_ring->queue_index);
1294
1295		netif_info(interface, probe, tx_ring->netdev,
1296			   "tx hang %d detected on queue %d, resetting interface\n",
1297			   interface->tx_timeout_count + 1,
1298			   tx_ring->queue_index);
1299
1300		fm10k_tx_timeout_reset(interface);
1301
1302		/* the netdev is about to reset, no point in enabling stuff */
1303		return true;
1304	}
1305
1306	/* notify netdev of completed buffers */
1307	netdev_tx_completed_queue(txring_txq(tx_ring),
1308				  total_packets, total_bytes);
1309
1310#define TX_WAKE_THRESHOLD min_t(u16, FM10K_MIN_TXD - 1, DESC_NEEDED * 2)
1311	if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
1312		     (fm10k_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD))) {
1313		/* Make sure that anybody stopping the queue after this
1314		 * sees the new next_to_clean.
1315		 */
1316		smp_mb();
1317		if (__netif_subqueue_stopped(tx_ring->netdev,
1318					     tx_ring->queue_index) &&
1319		    !test_bit(__FM10K_DOWN, interface->state)) {
1320			netif_wake_subqueue(tx_ring->netdev,
1321					    tx_ring->queue_index);
1322			++tx_ring->tx_stats.restart_queue;
1323		}
1324	}
1325
1326	return !!budget;
1327}
1328
1329/**
1330 * fm10k_update_itr - update the dynamic ITR value based on packet size
1331 *
1332 *      Stores a new ITR value based on strictly on packet size.  The
1333 *      divisors and thresholds used by this function were determined based
1334 *      on theoretical maximum wire speed and testing data, in order to
1335 *      minimize response time while increasing bulk throughput.
1336 *
1337 * @ring_container: Container for rings to have ITR updated
1338 **/
1339static void fm10k_update_itr(struct fm10k_ring_container *ring_container)
1340{
1341	unsigned int avg_wire_size, packets, itr_round;
1342
1343	/* Only update ITR if we are using adaptive setting */
1344	if (!ITR_IS_ADAPTIVE(ring_container->itr))
1345		goto clear_counts;
1346
1347	packets = ring_container->total_packets;
1348	if (!packets)
1349		goto clear_counts;
1350
1351	avg_wire_size = ring_container->total_bytes / packets;
1352
1353	/* The following is a crude approximation of:
1354	 *  wmem_default / (size + overhead) = desired_pkts_per_int
1355	 *  rate / bits_per_byte / (size + ethernet overhead) = pkt_rate
1356	 *  (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value
1357	 *
1358	 * Assuming wmem_default is 212992 and overhead is 640 bytes per
1359	 * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the
1360	 * formula down to
1361	 *
1362	 *  (34 * (size + 24)) / (size + 640) = ITR
1363	 *
1364	 * We first do some math on the packet size and then finally bitshift
1365	 * by 8 after rounding up. We also have to account for PCIe link speed
1366	 * difference as ITR scales based on this.
1367	 */
1368	if (avg_wire_size <= 360) {
1369		/* Start at 250K ints/sec and gradually drop to 77K ints/sec */
1370		avg_wire_size *= 8;
1371		avg_wire_size += 376;
1372	} else if (avg_wire_size <= 1152) {
1373		/* 77K ints/sec to 45K ints/sec */
1374		avg_wire_size *= 3;
1375		avg_wire_size += 2176;
1376	} else if (avg_wire_size <= 1920) {
1377		/* 45K ints/sec to 38K ints/sec */
1378		avg_wire_size += 4480;
1379	} else {
1380		/* plateau at a limit of 38K ints/sec */
1381		avg_wire_size = 6656;
1382	}
1383
1384	/* Perform final bitshift for division after rounding up to ensure
1385	 * that the calculation will never get below a 1. The bit shift
1386	 * accounts for changes in the ITR due to PCIe link speed.
1387	 */
1388	itr_round = READ_ONCE(ring_container->itr_scale) + 8;
1389	avg_wire_size += BIT(itr_round) - 1;
1390	avg_wire_size >>= itr_round;
1391
1392	/* write back value and retain adaptive flag */
1393	ring_container->itr = avg_wire_size | FM10K_ITR_ADAPTIVE;
1394
1395clear_counts:
1396	ring_container->total_bytes = 0;
1397	ring_container->total_packets = 0;
1398}
1399
1400static void fm10k_qv_enable(struct fm10k_q_vector *q_vector)
1401{
1402	/* Enable auto-mask and clear the current mask */
1403	u32 itr = FM10K_ITR_ENABLE;
1404
1405	/* Update Tx ITR */
1406	fm10k_update_itr(&q_vector->tx);
1407
1408	/* Update Rx ITR */
1409	fm10k_update_itr(&q_vector->rx);
1410
1411	/* Store Tx itr in timer slot 0 */
1412	itr |= (q_vector->tx.itr & FM10K_ITR_MAX);
1413
1414	/* Shift Rx itr to timer slot 1 */
1415	itr |= (q_vector->rx.itr & FM10K_ITR_MAX) << FM10K_ITR_INTERVAL1_SHIFT;
1416
1417	/* Write the final value to the ITR register */
1418	writel(itr, q_vector->itr);
1419}
1420
1421static int fm10k_poll(struct napi_struct *napi, int budget)
1422{
1423	struct fm10k_q_vector *q_vector =
1424			       container_of(napi, struct fm10k_q_vector, napi);
1425	struct fm10k_ring *ring;
1426	int per_ring_budget, work_done = 0;
1427	bool clean_complete = true;
1428
1429	fm10k_for_each_ring(ring, q_vector->tx) {
1430		if (!fm10k_clean_tx_irq(q_vector, ring, budget))
1431			clean_complete = false;
1432	}
1433
1434	/* Handle case where we are called by netpoll with a budget of 0 */
1435	if (budget <= 0)
1436		return budget;
1437
1438	/* attempt to distribute budget to each queue fairly, but don't
1439	 * allow the budget to go below 1 because we'll exit polling
1440	 */
1441	if (q_vector->rx.count > 1)
1442		per_ring_budget = max(budget / q_vector->rx.count, 1);
1443	else
1444		per_ring_budget = budget;
1445
1446	fm10k_for_each_ring(ring, q_vector->rx) {
1447		int work = fm10k_clean_rx_irq(q_vector, ring, per_ring_budget);
1448
1449		work_done += work;
1450		if (work >= per_ring_budget)
1451			clean_complete = false;
1452	}
1453
1454	/* If all work not completed, return budget and keep polling */
1455	if (!clean_complete)
1456		return budget;
1457
1458	/* Exit the polling mode, but don't re-enable interrupts if stack might
1459	 * poll us due to busy-polling
1460	 */
1461	if (likely(napi_complete_done(napi, work_done)))
1462		fm10k_qv_enable(q_vector);
1463
1464	return min(work_done, budget - 1);
1465}
1466
1467/**
1468 * fm10k_set_qos_queues: Allocate queues for a QOS-enabled device
1469 * @interface: board private structure to initialize
1470 *
1471 * When QoS (Quality of Service) is enabled, allocate queues for
1472 * each traffic class.  If multiqueue isn't available,then abort QoS
1473 * initialization.
1474 *
1475 * This function handles all combinations of Qos and RSS.
1476 *
1477 **/
1478static bool fm10k_set_qos_queues(struct fm10k_intfc *interface)
1479{
1480	struct net_device *dev = interface->netdev;
1481	struct fm10k_ring_feature *f;
1482	int rss_i, i;
1483	int pcs;
1484
1485	/* Map queue offset and counts onto allocated tx queues */
1486	pcs = netdev_get_num_tc(dev);
1487
1488	if (pcs <= 1)
1489		return false;
1490
1491	/* set QoS mask and indices */
1492	f = &interface->ring_feature[RING_F_QOS];
1493	f->indices = pcs;
1494	f->mask = BIT(fls(pcs - 1)) - 1;
1495
1496	/* determine the upper limit for our current DCB mode */
1497	rss_i = interface->hw.mac.max_queues / pcs;
1498	rss_i = BIT(fls(rss_i) - 1);
1499
1500	/* set RSS mask and indices */
1501	f = &interface->ring_feature[RING_F_RSS];
1502	rss_i = min_t(u16, rss_i, f->limit);
1503	f->indices = rss_i;
1504	f->mask = BIT(fls(rss_i - 1)) - 1;
1505
1506	/* configure pause class to queue mapping */
1507	for (i = 0; i < pcs; i++)
1508		netdev_set_tc_queue(dev, i, rss_i, rss_i * i);
1509
1510	interface->num_rx_queues = rss_i * pcs;
1511	interface->num_tx_queues = rss_i * pcs;
1512
1513	return true;
1514}
1515
1516/**
1517 * fm10k_set_rss_queues: Allocate queues for RSS
1518 * @interface: board private structure to initialize
1519 *
1520 * This is our "base" multiqueue mode.  RSS (Receive Side Scaling) will try
1521 * to allocate one Rx queue per CPU, and if available, one Tx queue per CPU.
1522 *
1523 **/
1524static bool fm10k_set_rss_queues(struct fm10k_intfc *interface)
1525{
1526	struct fm10k_ring_feature *f;
1527	u16 rss_i;
1528
1529	f = &interface->ring_feature[RING_F_RSS];
1530	rss_i = min_t(u16, interface->hw.mac.max_queues, f->limit);
1531
1532	/* record indices and power of 2 mask for RSS */
1533	f->indices = rss_i;
1534	f->mask = BIT(fls(rss_i - 1)) - 1;
1535
1536	interface->num_rx_queues = rss_i;
1537	interface->num_tx_queues = rss_i;
1538
1539	return true;
1540}
1541
1542/**
1543 * fm10k_set_num_queues: Allocate queues for device, feature dependent
1544 * @interface: board private structure to initialize
1545 *
1546 * This is the top level queue allocation routine.  The order here is very
1547 * important, starting with the "most" number of features turned on at once,
1548 * and ending with the smallest set of features.  This way large combinations
1549 * can be allocated if they're turned on, and smaller combinations are the
1550 * fall through conditions.
1551 *
1552 **/
1553static void fm10k_set_num_queues(struct fm10k_intfc *interface)
1554{
1555	/* Attempt to setup QoS and RSS first */
1556	if (fm10k_set_qos_queues(interface))
1557		return;
1558
1559	/* If we don't have QoS, just fallback to only RSS. */
1560	fm10k_set_rss_queues(interface);
1561}
1562
1563/**
1564 * fm10k_reset_num_queues - Reset the number of queues to zero
1565 * @interface: board private structure
1566 *
1567 * This function should be called whenever we need to reset the number of
1568 * queues after an error condition.
1569 */
1570static void fm10k_reset_num_queues(struct fm10k_intfc *interface)
1571{
1572	interface->num_tx_queues = 0;
1573	interface->num_rx_queues = 0;
1574	interface->num_q_vectors = 0;
1575}
1576
1577/**
1578 * fm10k_alloc_q_vector - Allocate memory for a single interrupt vector
1579 * @interface: board private structure to initialize
1580 * @v_count: q_vectors allocated on interface, used for ring interleaving
1581 * @v_idx: index of vector in interface struct
1582 * @txr_count: total number of Tx rings to allocate
1583 * @txr_idx: index of first Tx ring to allocate
1584 * @rxr_count: total number of Rx rings to allocate
1585 * @rxr_idx: index of first Rx ring to allocate
1586 *
1587 * We allocate one q_vector.  If allocation fails we return -ENOMEM.
1588 **/
1589static int fm10k_alloc_q_vector(struct fm10k_intfc *interface,
1590				unsigned int v_count, unsigned int v_idx,
1591				unsigned int txr_count, unsigned int txr_idx,
1592				unsigned int rxr_count, unsigned int rxr_idx)
1593{
1594	struct fm10k_q_vector *q_vector;
1595	struct fm10k_ring *ring;
1596	int ring_count;
1597
1598	ring_count = txr_count + rxr_count;
1599
1600	/* allocate q_vector and rings */
1601	q_vector = kzalloc(struct_size(q_vector, ring, ring_count), GFP_KERNEL);
1602	if (!q_vector)
1603		return -ENOMEM;
1604
1605	/* initialize NAPI */
1606	netif_napi_add(interface->netdev, &q_vector->napi, fm10k_poll);
 
1607
1608	/* tie q_vector and interface together */
1609	interface->q_vector[v_idx] = q_vector;
1610	q_vector->interface = interface;
1611	q_vector->v_idx = v_idx;
1612
1613	/* initialize pointer to rings */
1614	ring = q_vector->ring;
1615
1616	/* save Tx ring container info */
1617	q_vector->tx.ring = ring;
1618	q_vector->tx.work_limit = FM10K_DEFAULT_TX_WORK;
1619	q_vector->tx.itr = interface->tx_itr;
1620	q_vector->tx.itr_scale = interface->hw.mac.itr_scale;
1621	q_vector->tx.count = txr_count;
1622
1623	while (txr_count) {
1624		/* assign generic ring traits */
1625		ring->dev = &interface->pdev->dev;
1626		ring->netdev = interface->netdev;
1627
1628		/* configure backlink on ring */
1629		ring->q_vector = q_vector;
1630
1631		/* apply Tx specific ring traits */
1632		ring->count = interface->tx_ring_count;
1633		ring->queue_index = txr_idx;
1634
1635		/* assign ring to interface */
1636		interface->tx_ring[txr_idx] = ring;
1637
1638		/* update count and index */
1639		txr_count--;
1640		txr_idx += v_count;
1641
1642		/* push pointer to next ring */
1643		ring++;
1644	}
1645
1646	/* save Rx ring container info */
1647	q_vector->rx.ring = ring;
1648	q_vector->rx.itr = interface->rx_itr;
1649	q_vector->rx.itr_scale = interface->hw.mac.itr_scale;
1650	q_vector->rx.count = rxr_count;
1651
1652	while (rxr_count) {
1653		/* assign generic ring traits */
1654		ring->dev = &interface->pdev->dev;
1655		ring->netdev = interface->netdev;
1656		rcu_assign_pointer(ring->l2_accel, interface->l2_accel);
1657
1658		/* configure backlink on ring */
1659		ring->q_vector = q_vector;
1660
1661		/* apply Rx specific ring traits */
1662		ring->count = interface->rx_ring_count;
1663		ring->queue_index = rxr_idx;
1664
1665		/* assign ring to interface */
1666		interface->rx_ring[rxr_idx] = ring;
1667
1668		/* update count and index */
1669		rxr_count--;
1670		rxr_idx += v_count;
1671
1672		/* push pointer to next ring */
1673		ring++;
1674	}
1675
1676	fm10k_dbg_q_vector_init(q_vector);
1677
1678	return 0;
1679}
1680
1681/**
1682 * fm10k_free_q_vector - Free memory allocated for specific interrupt vector
1683 * @interface: board private structure to initialize
1684 * @v_idx: Index of vector to be freed
1685 *
1686 * This function frees the memory allocated to the q_vector.  In addition if
1687 * NAPI is enabled it will delete any references to the NAPI struct prior
1688 * to freeing the q_vector.
1689 **/
1690static void fm10k_free_q_vector(struct fm10k_intfc *interface, int v_idx)
1691{
1692	struct fm10k_q_vector *q_vector = interface->q_vector[v_idx];
1693	struct fm10k_ring *ring;
1694
1695	fm10k_dbg_q_vector_exit(q_vector);
1696
1697	fm10k_for_each_ring(ring, q_vector->tx)
1698		interface->tx_ring[ring->queue_index] = NULL;
1699
1700	fm10k_for_each_ring(ring, q_vector->rx)
1701		interface->rx_ring[ring->queue_index] = NULL;
1702
1703	interface->q_vector[v_idx] = NULL;
1704	netif_napi_del(&q_vector->napi);
1705	kfree_rcu(q_vector, rcu);
1706}
1707
1708/**
1709 * fm10k_alloc_q_vectors - Allocate memory for interrupt vectors
1710 * @interface: board private structure to initialize
1711 *
1712 * We allocate one q_vector per queue interrupt.  If allocation fails we
1713 * return -ENOMEM.
1714 **/
1715static int fm10k_alloc_q_vectors(struct fm10k_intfc *interface)
1716{
1717	unsigned int q_vectors = interface->num_q_vectors;
1718	unsigned int rxr_remaining = interface->num_rx_queues;
1719	unsigned int txr_remaining = interface->num_tx_queues;
1720	unsigned int rxr_idx = 0, txr_idx = 0, v_idx = 0;
1721	int err;
1722
1723	if (q_vectors >= (rxr_remaining + txr_remaining)) {
1724		for (; rxr_remaining; v_idx++) {
1725			err = fm10k_alloc_q_vector(interface, q_vectors, v_idx,
1726						   0, 0, 1, rxr_idx);
1727			if (err)
1728				goto err_out;
1729
1730			/* update counts and index */
1731			rxr_remaining--;
1732			rxr_idx++;
1733		}
1734	}
1735
1736	for (; v_idx < q_vectors; v_idx++) {
1737		int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors - v_idx);
1738		int tqpv = DIV_ROUND_UP(txr_remaining, q_vectors - v_idx);
1739
1740		err = fm10k_alloc_q_vector(interface, q_vectors, v_idx,
1741					   tqpv, txr_idx,
1742					   rqpv, rxr_idx);
1743
1744		if (err)
1745			goto err_out;
1746
1747		/* update counts and index */
1748		rxr_remaining -= rqpv;
1749		txr_remaining -= tqpv;
1750		rxr_idx++;
1751		txr_idx++;
1752	}
1753
1754	return 0;
1755
1756err_out:
1757	fm10k_reset_num_queues(interface);
1758
1759	while (v_idx--)
1760		fm10k_free_q_vector(interface, v_idx);
1761
1762	return -ENOMEM;
1763}
1764
1765/**
1766 * fm10k_free_q_vectors - Free memory allocated for interrupt vectors
1767 * @interface: board private structure to initialize
1768 *
1769 * This function frees the memory allocated to the q_vectors.  In addition if
1770 * NAPI is enabled it will delete any references to the NAPI struct prior
1771 * to freeing the q_vector.
1772 **/
1773static void fm10k_free_q_vectors(struct fm10k_intfc *interface)
1774{
1775	int v_idx = interface->num_q_vectors;
1776
1777	fm10k_reset_num_queues(interface);
1778
1779	while (v_idx--)
1780		fm10k_free_q_vector(interface, v_idx);
1781}
1782
1783/**
1784 * fm10k_reset_msix_capability - reset MSI-X capability
1785 * @interface: board private structure to initialize
1786 *
1787 * Reset the MSI-X capability back to its starting state
1788 **/
1789static void fm10k_reset_msix_capability(struct fm10k_intfc *interface)
1790{
1791	pci_disable_msix(interface->pdev);
1792	kfree(interface->msix_entries);
1793	interface->msix_entries = NULL;
1794}
1795
1796/**
1797 * fm10k_init_msix_capability - configure MSI-X capability
1798 * @interface: board private structure to initialize
1799 *
1800 * Attempt to configure the interrupts using the best available
1801 * capabilities of the hardware and the kernel.
1802 **/
1803static int fm10k_init_msix_capability(struct fm10k_intfc *interface)
1804{
1805	struct fm10k_hw *hw = &interface->hw;
1806	int v_budget, vector;
1807
1808	/* It's easy to be greedy for MSI-X vectors, but it really
1809	 * doesn't do us much good if we have a lot more vectors
1810	 * than CPU's.  So let's be conservative and only ask for
1811	 * (roughly) the same number of vectors as there are CPU's.
1812	 * the default is to use pairs of vectors
1813	 */
1814	v_budget = max(interface->num_rx_queues, interface->num_tx_queues);
1815	v_budget = min_t(u16, v_budget, num_online_cpus());
1816
1817	/* account for vectors not related to queues */
1818	v_budget += NON_Q_VECTORS;
1819
1820	/* At the same time, hardware can only support a maximum of
1821	 * hw.mac->max_msix_vectors vectors.  With features
1822	 * such as RSS and VMDq, we can easily surpass the number of Rx and Tx
1823	 * descriptor queues supported by our device.  Thus, we cap it off in
1824	 * those rare cases where the cpu count also exceeds our vector limit.
1825	 */
1826	v_budget = min_t(int, v_budget, hw->mac.max_msix_vectors);
1827
1828	/* A failure in MSI-X entry allocation is fatal. */
1829	interface->msix_entries = kcalloc(v_budget, sizeof(struct msix_entry),
1830					  GFP_KERNEL);
1831	if (!interface->msix_entries)
1832		return -ENOMEM;
1833
1834	/* populate entry values */
1835	for (vector = 0; vector < v_budget; vector++)
1836		interface->msix_entries[vector].entry = vector;
1837
1838	/* Attempt to enable MSI-X with requested value */
1839	v_budget = pci_enable_msix_range(interface->pdev,
1840					 interface->msix_entries,
1841					 MIN_MSIX_COUNT(hw),
1842					 v_budget);
1843	if (v_budget < 0) {
1844		kfree(interface->msix_entries);
1845		interface->msix_entries = NULL;
1846		return v_budget;
1847	}
1848
1849	/* record the number of queues available for q_vectors */
1850	interface->num_q_vectors = v_budget - NON_Q_VECTORS;
1851
1852	return 0;
1853}
1854
1855/**
1856 * fm10k_cache_ring_qos - Descriptor ring to register mapping for QoS
1857 * @interface: Interface structure continaining rings and devices
1858 *
1859 * Cache the descriptor ring offsets for Qos
1860 **/
1861static bool fm10k_cache_ring_qos(struct fm10k_intfc *interface)
1862{
1863	struct net_device *dev = interface->netdev;
1864	int pc, offset, rss_i, i;
1865	u16 pc_stride = interface->ring_feature[RING_F_QOS].mask + 1;
1866	u8 num_pcs = netdev_get_num_tc(dev);
1867
1868	if (num_pcs <= 1)
1869		return false;
1870
1871	rss_i = interface->ring_feature[RING_F_RSS].indices;
1872
1873	for (pc = 0, offset = 0; pc < num_pcs; pc++, offset += rss_i) {
1874		int q_idx = pc;
1875
1876		for (i = 0; i < rss_i; i++) {
1877			interface->tx_ring[offset + i]->reg_idx = q_idx;
1878			interface->tx_ring[offset + i]->qos_pc = pc;
1879			interface->rx_ring[offset + i]->reg_idx = q_idx;
1880			interface->rx_ring[offset + i]->qos_pc = pc;
1881			q_idx += pc_stride;
1882		}
1883	}
1884
1885	return true;
1886}
1887
1888/**
1889 * fm10k_cache_ring_rss - Descriptor ring to register mapping for RSS
1890 * @interface: Interface structure continaining rings and devices
1891 *
1892 * Cache the descriptor ring offsets for RSS
1893 **/
1894static void fm10k_cache_ring_rss(struct fm10k_intfc *interface)
1895{
1896	int i;
1897
1898	for (i = 0; i < interface->num_rx_queues; i++)
1899		interface->rx_ring[i]->reg_idx = i;
1900
1901	for (i = 0; i < interface->num_tx_queues; i++)
1902		interface->tx_ring[i]->reg_idx = i;
1903}
1904
1905/**
1906 * fm10k_assign_rings - Map rings to network devices
1907 * @interface: Interface structure containing rings and devices
1908 *
1909 * This function is meant to go though and configure both the network
1910 * devices so that they contain rings, and configure the rings so that
1911 * they function with their network devices.
1912 **/
1913static void fm10k_assign_rings(struct fm10k_intfc *interface)
1914{
1915	if (fm10k_cache_ring_qos(interface))
1916		return;
1917
1918	fm10k_cache_ring_rss(interface);
1919}
1920
1921static void fm10k_init_reta(struct fm10k_intfc *interface)
1922{
1923	u16 i, rss_i = interface->ring_feature[RING_F_RSS].indices;
1924	u32 reta;
1925
1926	/* If the Rx flow indirection table has been configured manually, we
1927	 * need to maintain it when possible.
1928	 */
1929	if (netif_is_rxfh_configured(interface->netdev)) {
1930		for (i = FM10K_RETA_SIZE; i--;) {
1931			reta = interface->reta[i];
1932			if ((((reta << 24) >> 24) < rss_i) &&
1933			    (((reta << 16) >> 24) < rss_i) &&
1934			    (((reta <<  8) >> 24) < rss_i) &&
1935			    (((reta)       >> 24) < rss_i))
1936				continue;
1937
1938			/* this should never happen */
1939			dev_err(&interface->pdev->dev,
1940				"RSS indirection table assigned flows out of queue bounds. Reconfiguring.\n");
1941			goto repopulate_reta;
1942		}
1943
1944		/* do nothing if all of the elements are in bounds */
1945		return;
1946	}
1947
1948repopulate_reta:
1949	fm10k_write_reta(interface, NULL);
1950}
1951
1952/**
1953 * fm10k_init_queueing_scheme - Determine proper queueing scheme
1954 * @interface: board private structure to initialize
1955 *
1956 * We determine which queueing scheme to use based on...
1957 * - Hardware queue count (num_*_queues)
1958 *   - defined by miscellaneous hardware support/features (RSS, etc.)
1959 **/
1960int fm10k_init_queueing_scheme(struct fm10k_intfc *interface)
1961{
1962	int err;
1963
1964	/* Number of supported queues */
1965	fm10k_set_num_queues(interface);
1966
1967	/* Configure MSI-X capability */
1968	err = fm10k_init_msix_capability(interface);
1969	if (err) {
1970		dev_err(&interface->pdev->dev,
1971			"Unable to initialize MSI-X capability\n");
1972		goto err_init_msix;
1973	}
1974
1975	/* Allocate memory for queues */
1976	err = fm10k_alloc_q_vectors(interface);
1977	if (err) {
1978		dev_err(&interface->pdev->dev,
1979			"Unable to allocate queue vectors\n");
1980		goto err_alloc_q_vectors;
1981	}
1982
1983	/* Map rings to devices, and map devices to physical queues */
1984	fm10k_assign_rings(interface);
1985
1986	/* Initialize RSS redirection table */
1987	fm10k_init_reta(interface);
1988
1989	return 0;
1990
1991err_alloc_q_vectors:
1992	fm10k_reset_msix_capability(interface);
1993err_init_msix:
1994	fm10k_reset_num_queues(interface);
1995	return err;
1996}
1997
1998/**
1999 * fm10k_clear_queueing_scheme - Clear the current queueing scheme settings
2000 * @interface: board private structure to clear queueing scheme on
2001 *
2002 * We go through and clear queueing specific resources and reset the structure
2003 * to pre-load conditions
2004 **/
2005void fm10k_clear_queueing_scheme(struct fm10k_intfc *interface)
2006{
2007	fm10k_free_q_vectors(interface);
2008	fm10k_reset_msix_capability(interface);
2009}
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright(c) 2013 - 2019 Intel Corporation. */
   3
   4#include <linux/types.h>
   5#include <linux/module.h>
   6#include <net/ipv6.h>
   7#include <net/ip.h>
   8#include <net/tcp.h>
   9#include <linux/if_macvlan.h>
  10#include <linux/prefetch.h>
  11
  12#include "fm10k.h"
  13
  14#define DRV_SUMMARY	"Intel(R) Ethernet Switch Host Interface Driver"
  15char fm10k_driver_name[] = "fm10k";
  16static const char fm10k_driver_string[] = DRV_SUMMARY;
  17static const char fm10k_copyright[] =
  18	"Copyright(c) 2013 - 2019 Intel Corporation.";
  19
  20MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
  21MODULE_DESCRIPTION(DRV_SUMMARY);
  22MODULE_LICENSE("GPL v2");
  23
  24/* single workqueue for entire fm10k driver */
  25struct workqueue_struct *fm10k_workqueue;
  26
  27/**
  28 * fm10k_init_module - Driver Registration Routine
  29 *
  30 * fm10k_init_module is the first routine called when the driver is
  31 * loaded.  All it does is register with the PCI subsystem.
  32 **/
  33static int __init fm10k_init_module(void)
  34{
 
 
  35	pr_info("%s\n", fm10k_driver_string);
  36	pr_info("%s\n", fm10k_copyright);
  37
  38	/* create driver workqueue */
  39	fm10k_workqueue = alloc_workqueue("%s", WQ_MEM_RECLAIM, 0,
  40					  fm10k_driver_name);
  41	if (!fm10k_workqueue)
  42		return -ENOMEM;
  43
  44	fm10k_dbg_init();
  45
  46	return fm10k_register_pci_driver();
 
 
 
 
 
 
  47}
  48module_init(fm10k_init_module);
  49
  50/**
  51 * fm10k_exit_module - Driver Exit Cleanup Routine
  52 *
  53 * fm10k_exit_module is called just before the driver is removed
  54 * from memory.
  55 **/
  56static void __exit fm10k_exit_module(void)
  57{
  58	fm10k_unregister_pci_driver();
  59
  60	fm10k_dbg_exit();
  61
  62	/* destroy driver workqueue */
  63	destroy_workqueue(fm10k_workqueue);
  64}
  65module_exit(fm10k_exit_module);
  66
  67static bool fm10k_alloc_mapped_page(struct fm10k_ring *rx_ring,
  68				    struct fm10k_rx_buffer *bi)
  69{
  70	struct page *page = bi->page;
  71	dma_addr_t dma;
  72
  73	/* Only page will be NULL if buffer was consumed */
  74	if (likely(page))
  75		return true;
  76
  77	/* alloc new page for storage */
  78	page = dev_alloc_page();
  79	if (unlikely(!page)) {
  80		rx_ring->rx_stats.alloc_failed++;
  81		return false;
  82	}
  83
  84	/* map page for use */
  85	dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
  86
  87	/* if mapping failed free memory back to system since
  88	 * there isn't much point in holding memory we can't use
  89	 */
  90	if (dma_mapping_error(rx_ring->dev, dma)) {
  91		__free_page(page);
  92
  93		rx_ring->rx_stats.alloc_failed++;
  94		return false;
  95	}
  96
  97	bi->dma = dma;
  98	bi->page = page;
  99	bi->page_offset = 0;
 100
 101	return true;
 102}
 103
 104/**
 105 * fm10k_alloc_rx_buffers - Replace used receive buffers
 106 * @rx_ring: ring to place buffers on
 107 * @cleaned_count: number of buffers to replace
 108 **/
 109void fm10k_alloc_rx_buffers(struct fm10k_ring *rx_ring, u16 cleaned_count)
 110{
 111	union fm10k_rx_desc *rx_desc;
 112	struct fm10k_rx_buffer *bi;
 113	u16 i = rx_ring->next_to_use;
 114
 115	/* nothing to do */
 116	if (!cleaned_count)
 117		return;
 118
 119	rx_desc = FM10K_RX_DESC(rx_ring, i);
 120	bi = &rx_ring->rx_buffer[i];
 121	i -= rx_ring->count;
 122
 123	do {
 124		if (!fm10k_alloc_mapped_page(rx_ring, bi))
 125			break;
 126
 127		/* Refresh the desc even if buffer_addrs didn't change
 128		 * because each write-back erases this info.
 129		 */
 130		rx_desc->q.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);
 131
 132		rx_desc++;
 133		bi++;
 134		i++;
 135		if (unlikely(!i)) {
 136			rx_desc = FM10K_RX_DESC(rx_ring, 0);
 137			bi = rx_ring->rx_buffer;
 138			i -= rx_ring->count;
 139		}
 140
 141		/* clear the status bits for the next_to_use descriptor */
 142		rx_desc->d.staterr = 0;
 143
 144		cleaned_count--;
 145	} while (cleaned_count);
 146
 147	i += rx_ring->count;
 148
 149	if (rx_ring->next_to_use != i) {
 150		/* record the next descriptor to use */
 151		rx_ring->next_to_use = i;
 152
 153		/* update next to alloc since we have filled the ring */
 154		rx_ring->next_to_alloc = i;
 155
 156		/* Force memory writes to complete before letting h/w
 157		 * know there are new descriptors to fetch.  (Only
 158		 * applicable for weak-ordered memory model archs,
 159		 * such as IA-64).
 160		 */
 161		wmb();
 162
 163		/* notify hardware of new descriptors */
 164		writel(i, rx_ring->tail);
 165	}
 166}
 167
 168/**
 169 * fm10k_reuse_rx_page - page flip buffer and store it back on the ring
 170 * @rx_ring: rx descriptor ring to store buffers on
 171 * @old_buff: donor buffer to have page reused
 172 *
 173 * Synchronizes page for reuse by the interface
 174 **/
 175static void fm10k_reuse_rx_page(struct fm10k_ring *rx_ring,
 176				struct fm10k_rx_buffer *old_buff)
 177{
 178	struct fm10k_rx_buffer *new_buff;
 179	u16 nta = rx_ring->next_to_alloc;
 180
 181	new_buff = &rx_ring->rx_buffer[nta];
 182
 183	/* update, and store next to alloc */
 184	nta++;
 185	rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
 186
 187	/* transfer page from old buffer to new buffer */
 188	*new_buff = *old_buff;
 189
 190	/* sync the buffer for use by the device */
 191	dma_sync_single_range_for_device(rx_ring->dev, old_buff->dma,
 192					 old_buff->page_offset,
 193					 FM10K_RX_BUFSZ,
 194					 DMA_FROM_DEVICE);
 195}
 196
 197static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer,
 198				    struct page *page,
 199				    unsigned int __maybe_unused truesize)
 200{
 201	/* avoid re-using remote and pfmemalloc pages */
 202	if (!dev_page_is_reusable(page))
 203		return false;
 204
 205#if (PAGE_SIZE < 8192)
 206	/* if we are only owner of page we can reuse it */
 207	if (unlikely(page_count(page) != 1))
 208		return false;
 209
 210	/* flip page offset to other buffer */
 211	rx_buffer->page_offset ^= FM10K_RX_BUFSZ;
 212#else
 213	/* move offset up to the next cache line */
 214	rx_buffer->page_offset += truesize;
 215
 216	if (rx_buffer->page_offset > (PAGE_SIZE - FM10K_RX_BUFSZ))
 217		return false;
 218#endif
 219
 220	/* Even if we own the page, we are not allowed to use atomic_set()
 221	 * This would break get_page_unless_zero() users.
 222	 */
 223	page_ref_inc(page);
 224
 225	return true;
 226}
 227
 228/**
 229 * fm10k_add_rx_frag - Add contents of Rx buffer to sk_buff
 230 * @rx_buffer: buffer containing page to add
 231 * @size: packet size from rx_desc
 232 * @rx_desc: descriptor containing length of buffer written by hardware
 233 * @skb: sk_buff to place the data into
 234 *
 235 * This function will add the data contained in rx_buffer->page to the skb.
 236 * This is done either through a direct copy if the data in the buffer is
 237 * less than the skb header size, otherwise it will just attach the page as
 238 * a frag to the skb.
 239 *
 240 * The function will then update the page offset if necessary and return
 241 * true if the buffer can be reused by the interface.
 242 **/
 243static bool fm10k_add_rx_frag(struct fm10k_rx_buffer *rx_buffer,
 244			      unsigned int size,
 245			      union fm10k_rx_desc *rx_desc,
 246			      struct sk_buff *skb)
 247{
 248	struct page *page = rx_buffer->page;
 249	unsigned char *va = page_address(page) + rx_buffer->page_offset;
 250#if (PAGE_SIZE < 8192)
 251	unsigned int truesize = FM10K_RX_BUFSZ;
 252#else
 253	unsigned int truesize = ALIGN(size, 512);
 254#endif
 255	unsigned int pull_len;
 256
 257	if (unlikely(skb_is_nonlinear(skb)))
 258		goto add_tail_frag;
 259
 260	if (likely(size <= FM10K_RX_HDR_LEN)) {
 261		memcpy(__skb_put(skb, size), va, ALIGN(size, sizeof(long)));
 262
 263		/* page is reusable, we can reuse buffer as-is */
 264		if (dev_page_is_reusable(page))
 265			return true;
 266
 267		/* this page cannot be reused so discard it */
 268		__free_page(page);
 269		return false;
 270	}
 271
 272	/* we need the header to contain the greater of either ETH_HLEN or
 273	 * 60 bytes if the skb->len is less than 60 for skb_pad.
 274	 */
 275	pull_len = eth_get_headlen(skb->dev, va, FM10K_RX_HDR_LEN);
 276
 277	/* align pull length to size of long to optimize memcpy performance */
 278	memcpy(__skb_put(skb, pull_len), va, ALIGN(pull_len, sizeof(long)));
 279
 280	/* update all of the pointers */
 281	va += pull_len;
 282	size -= pull_len;
 283
 284add_tail_frag:
 285	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
 286			(unsigned long)va & ~PAGE_MASK, size, truesize);
 287
 288	return fm10k_can_reuse_rx_page(rx_buffer, page, truesize);
 289}
 290
 291static struct sk_buff *fm10k_fetch_rx_buffer(struct fm10k_ring *rx_ring,
 292					     union fm10k_rx_desc *rx_desc,
 293					     struct sk_buff *skb)
 294{
 295	unsigned int size = le16_to_cpu(rx_desc->w.length);
 296	struct fm10k_rx_buffer *rx_buffer;
 297	struct page *page;
 298
 299	rx_buffer = &rx_ring->rx_buffer[rx_ring->next_to_clean];
 300	page = rx_buffer->page;
 301	prefetchw(page);
 302
 303	if (likely(!skb)) {
 304		void *page_addr = page_address(page) +
 305				  rx_buffer->page_offset;
 306
 307		/* prefetch first cache line of first page */
 308		net_prefetch(page_addr);
 309
 310		/* allocate a skb to store the frags */
 311		skb = napi_alloc_skb(&rx_ring->q_vector->napi,
 312				     FM10K_RX_HDR_LEN);
 313		if (unlikely(!skb)) {
 314			rx_ring->rx_stats.alloc_failed++;
 315			return NULL;
 316		}
 317
 318		/* we will be copying header into skb->data in
 319		 * pskb_may_pull so it is in our interest to prefetch
 320		 * it now to avoid a possible cache miss
 321		 */
 322		prefetchw(skb->data);
 323	}
 324
 325	/* we are reusing so sync this buffer for CPU use */
 326	dma_sync_single_range_for_cpu(rx_ring->dev,
 327				      rx_buffer->dma,
 328				      rx_buffer->page_offset,
 329				      size,
 330				      DMA_FROM_DEVICE);
 331
 332	/* pull page into skb */
 333	if (fm10k_add_rx_frag(rx_buffer, size, rx_desc, skb)) {
 334		/* hand second half of page back to the ring */
 335		fm10k_reuse_rx_page(rx_ring, rx_buffer);
 336	} else {
 337		/* we are not reusing the buffer so unmap it */
 338		dma_unmap_page(rx_ring->dev, rx_buffer->dma,
 339			       PAGE_SIZE, DMA_FROM_DEVICE);
 340	}
 341
 342	/* clear contents of rx_buffer */
 343	rx_buffer->page = NULL;
 344
 345	return skb;
 346}
 347
 348static inline void fm10k_rx_checksum(struct fm10k_ring *ring,
 349				     union fm10k_rx_desc *rx_desc,
 350				     struct sk_buff *skb)
 351{
 352	skb_checksum_none_assert(skb);
 353
 354	/* Rx checksum disabled via ethtool */
 355	if (!(ring->netdev->features & NETIF_F_RXCSUM))
 356		return;
 357
 358	/* TCP/UDP checksum error bit is set */
 359	if (fm10k_test_staterr(rx_desc,
 360			       FM10K_RXD_STATUS_L4E |
 361			       FM10K_RXD_STATUS_L4E2 |
 362			       FM10K_RXD_STATUS_IPE |
 363			       FM10K_RXD_STATUS_IPE2)) {
 364		ring->rx_stats.csum_err++;
 365		return;
 366	}
 367
 368	/* It must be a TCP or UDP packet with a valid checksum */
 369	if (fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_L4CS2))
 370		skb->encapsulation = true;
 371	else if (!fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_L4CS))
 372		return;
 373
 374	skb->ip_summed = CHECKSUM_UNNECESSARY;
 375
 376	ring->rx_stats.csum_good++;
 377}
 378
 379#define FM10K_RSS_L4_TYPES_MASK \
 380	(BIT(FM10K_RSSTYPE_IPV4_TCP) | \
 381	 BIT(FM10K_RSSTYPE_IPV4_UDP) | \
 382	 BIT(FM10K_RSSTYPE_IPV6_TCP) | \
 383	 BIT(FM10K_RSSTYPE_IPV6_UDP))
 384
 385static inline void fm10k_rx_hash(struct fm10k_ring *ring,
 386				 union fm10k_rx_desc *rx_desc,
 387				 struct sk_buff *skb)
 388{
 389	u16 rss_type;
 390
 391	if (!(ring->netdev->features & NETIF_F_RXHASH))
 392		return;
 393
 394	rss_type = le16_to_cpu(rx_desc->w.pkt_info) & FM10K_RXD_RSSTYPE_MASK;
 395	if (!rss_type)
 396		return;
 397
 398	skb_set_hash(skb, le32_to_cpu(rx_desc->d.rss),
 399		     (BIT(rss_type) & FM10K_RSS_L4_TYPES_MASK) ?
 400		     PKT_HASH_TYPE_L4 : PKT_HASH_TYPE_L3);
 401}
 402
 403static void fm10k_type_trans(struct fm10k_ring *rx_ring,
 404			     union fm10k_rx_desc __maybe_unused *rx_desc,
 405			     struct sk_buff *skb)
 406{
 407	struct net_device *dev = rx_ring->netdev;
 408	struct fm10k_l2_accel *l2_accel = rcu_dereference_bh(rx_ring->l2_accel);
 409
 410	/* check to see if DGLORT belongs to a MACVLAN */
 411	if (l2_accel) {
 412		u16 idx = le16_to_cpu(FM10K_CB(skb)->fi.w.dglort) - 1;
 413
 414		idx -= l2_accel->dglort;
 415		if (idx < l2_accel->size && l2_accel->macvlan[idx])
 416			dev = l2_accel->macvlan[idx];
 417		else
 418			l2_accel = NULL;
 419	}
 420
 421	/* Record Rx queue, or update macvlan statistics */
 422	if (!l2_accel)
 423		skb_record_rx_queue(skb, rx_ring->queue_index);
 424	else
 425		macvlan_count_rx(netdev_priv(dev), skb->len + ETH_HLEN, true,
 426				 false);
 427
 428	skb->protocol = eth_type_trans(skb, dev);
 429}
 430
 431/**
 432 * fm10k_process_skb_fields - Populate skb header fields from Rx descriptor
 433 * @rx_ring: rx descriptor ring packet is being transacted on
 434 * @rx_desc: pointer to the EOP Rx descriptor
 435 * @skb: pointer to current skb being populated
 436 *
 437 * This function checks the ring, descriptor, and packet information in
 438 * order to populate the hash, checksum, VLAN, timestamp, protocol, and
 439 * other fields within the skb.
 440 **/
 441static unsigned int fm10k_process_skb_fields(struct fm10k_ring *rx_ring,
 442					     union fm10k_rx_desc *rx_desc,
 443					     struct sk_buff *skb)
 444{
 445	unsigned int len = skb->len;
 446
 447	fm10k_rx_hash(rx_ring, rx_desc, skb);
 448
 449	fm10k_rx_checksum(rx_ring, rx_desc, skb);
 450
 451	FM10K_CB(skb)->tstamp = rx_desc->q.timestamp;
 452
 453	FM10K_CB(skb)->fi.w.vlan = rx_desc->w.vlan;
 454
 455	FM10K_CB(skb)->fi.d.glort = rx_desc->d.glort;
 456
 457	if (rx_desc->w.vlan) {
 458		u16 vid = le16_to_cpu(rx_desc->w.vlan);
 459
 460		if ((vid & VLAN_VID_MASK) != rx_ring->vid)
 461			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vid);
 462		else if (vid & VLAN_PRIO_MASK)
 463			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 464					       vid & VLAN_PRIO_MASK);
 465	}
 466
 467	fm10k_type_trans(rx_ring, rx_desc, skb);
 468
 469	return len;
 470}
 471
 472/**
 473 * fm10k_is_non_eop - process handling of non-EOP buffers
 474 * @rx_ring: Rx ring being processed
 475 * @rx_desc: Rx descriptor for current buffer
 476 *
 477 * This function updates next to clean.  If the buffer is an EOP buffer
 478 * this function exits returning false, otherwise it will place the
 479 * sk_buff in the next buffer to be chained and return true indicating
 480 * that this is in fact a non-EOP buffer.
 481 **/
 482static bool fm10k_is_non_eop(struct fm10k_ring *rx_ring,
 483			     union fm10k_rx_desc *rx_desc)
 484{
 485	u32 ntc = rx_ring->next_to_clean + 1;
 486
 487	/* fetch, update, and store next to clean */
 488	ntc = (ntc < rx_ring->count) ? ntc : 0;
 489	rx_ring->next_to_clean = ntc;
 490
 491	prefetch(FM10K_RX_DESC(rx_ring, ntc));
 492
 493	if (likely(fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_EOP)))
 494		return false;
 495
 496	return true;
 497}
 498
 499/**
 500 * fm10k_cleanup_headers - Correct corrupted or empty headers
 501 * @rx_ring: rx descriptor ring packet is being transacted on
 502 * @rx_desc: pointer to the EOP Rx descriptor
 503 * @skb: pointer to current skb being fixed
 504 *
 505 * Address the case where we are pulling data in on pages only
 506 * and as such no data is present in the skb header.
 507 *
 508 * In addition if skb is not at least 60 bytes we need to pad it so that
 509 * it is large enough to qualify as a valid Ethernet frame.
 510 *
 511 * Returns true if an error was encountered and skb was freed.
 512 **/
 513static bool fm10k_cleanup_headers(struct fm10k_ring *rx_ring,
 514				  union fm10k_rx_desc *rx_desc,
 515				  struct sk_buff *skb)
 516{
 517	if (unlikely((fm10k_test_staterr(rx_desc,
 518					 FM10K_RXD_STATUS_RXE)))) {
 519#define FM10K_TEST_RXD_BIT(rxd, bit) \
 520	((rxd)->w.csum_err & cpu_to_le16(bit))
 521		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_SWITCH_ERROR))
 522			rx_ring->rx_stats.switch_errors++;
 523		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_NO_DESCRIPTOR))
 524			rx_ring->rx_stats.drops++;
 525		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_PP_ERROR))
 526			rx_ring->rx_stats.pp_errors++;
 527		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_SWITCH_READY))
 528			rx_ring->rx_stats.link_errors++;
 529		if (FM10K_TEST_RXD_BIT(rx_desc, FM10K_RXD_ERR_TOO_BIG))
 530			rx_ring->rx_stats.length_errors++;
 531		dev_kfree_skb_any(skb);
 532		rx_ring->rx_stats.errors++;
 533		return true;
 534	}
 535
 536	/* if eth_skb_pad returns an error the skb was freed */
 537	if (eth_skb_pad(skb))
 538		return true;
 539
 540	return false;
 541}
 542
 543/**
 544 * fm10k_receive_skb - helper function to handle rx indications
 545 * @q_vector: structure containing interrupt and ring information
 546 * @skb: packet to send up
 547 **/
 548static void fm10k_receive_skb(struct fm10k_q_vector *q_vector,
 549			      struct sk_buff *skb)
 550{
 551	napi_gro_receive(&q_vector->napi, skb);
 552}
 553
 554static int fm10k_clean_rx_irq(struct fm10k_q_vector *q_vector,
 555			      struct fm10k_ring *rx_ring,
 556			      int budget)
 557{
 558	struct sk_buff *skb = rx_ring->skb;
 559	unsigned int total_bytes = 0, total_packets = 0;
 560	u16 cleaned_count = fm10k_desc_unused(rx_ring);
 561
 562	while (likely(total_packets < budget)) {
 563		union fm10k_rx_desc *rx_desc;
 564
 565		/* return some buffers to hardware, one at a time is too slow */
 566		if (cleaned_count >= FM10K_RX_BUFFER_WRITE) {
 567			fm10k_alloc_rx_buffers(rx_ring, cleaned_count);
 568			cleaned_count = 0;
 569		}
 570
 571		rx_desc = FM10K_RX_DESC(rx_ring, rx_ring->next_to_clean);
 572
 573		if (!rx_desc->d.staterr)
 574			break;
 575
 576		/* This memory barrier is needed to keep us from reading
 577		 * any other fields out of the rx_desc until we know the
 578		 * descriptor has been written back
 579		 */
 580		dma_rmb();
 581
 582		/* retrieve a buffer from the ring */
 583		skb = fm10k_fetch_rx_buffer(rx_ring, rx_desc, skb);
 584
 585		/* exit if we failed to retrieve a buffer */
 586		if (!skb)
 587			break;
 588
 589		cleaned_count++;
 590
 591		/* fetch next buffer in frame if non-eop */
 592		if (fm10k_is_non_eop(rx_ring, rx_desc))
 593			continue;
 594
 595		/* verify the packet layout is correct */
 596		if (fm10k_cleanup_headers(rx_ring, rx_desc, skb)) {
 597			skb = NULL;
 598			continue;
 599		}
 600
 601		/* populate checksum, timestamp, VLAN, and protocol */
 602		total_bytes += fm10k_process_skb_fields(rx_ring, rx_desc, skb);
 603
 604		fm10k_receive_skb(q_vector, skb);
 605
 606		/* reset skb pointer */
 607		skb = NULL;
 608
 609		/* update budget accounting */
 610		total_packets++;
 611	}
 612
 613	/* place incomplete frames back on ring for completion */
 614	rx_ring->skb = skb;
 615
 616	u64_stats_update_begin(&rx_ring->syncp);
 617	rx_ring->stats.packets += total_packets;
 618	rx_ring->stats.bytes += total_bytes;
 619	u64_stats_update_end(&rx_ring->syncp);
 620	q_vector->rx.total_packets += total_packets;
 621	q_vector->rx.total_bytes += total_bytes;
 622
 623	return total_packets;
 624}
 625
 626#define VXLAN_HLEN (sizeof(struct udphdr) + 8)
 627static struct ethhdr *fm10k_port_is_vxlan(struct sk_buff *skb)
 628{
 629	struct fm10k_intfc *interface = netdev_priv(skb->dev);
 630
 631	if (interface->vxlan_port != udp_hdr(skb)->dest)
 632		return NULL;
 633
 634	/* return offset of udp_hdr plus 8 bytes for VXLAN header */
 635	return (struct ethhdr *)(skb_transport_header(skb) + VXLAN_HLEN);
 636}
 637
 638#define FM10K_NVGRE_RESERVED0_FLAGS htons(0x9FFF)
 639#define NVGRE_TNI htons(0x2000)
 640struct fm10k_nvgre_hdr {
 641	__be16 flags;
 642	__be16 proto;
 643	__be32 tni;
 644};
 645
 646static struct ethhdr *fm10k_gre_is_nvgre(struct sk_buff *skb)
 647{
 648	struct fm10k_nvgre_hdr *nvgre_hdr;
 649	int hlen = ip_hdrlen(skb);
 650
 651	/* currently only IPv4 is supported due to hlen above */
 652	if (vlan_get_protocol(skb) != htons(ETH_P_IP))
 653		return NULL;
 654
 655	/* our transport header should be NVGRE */
 656	nvgre_hdr = (struct fm10k_nvgre_hdr *)(skb_network_header(skb) + hlen);
 657
 658	/* verify all reserved flags are 0 */
 659	if (nvgre_hdr->flags & FM10K_NVGRE_RESERVED0_FLAGS)
 660		return NULL;
 661
 662	/* report start of ethernet header */
 663	if (nvgre_hdr->flags & NVGRE_TNI)
 664		return (struct ethhdr *)(nvgre_hdr + 1);
 665
 666	return (struct ethhdr *)(&nvgre_hdr->tni);
 667}
 668
 669__be16 fm10k_tx_encap_offload(struct sk_buff *skb)
 670{
 671	u8 l4_hdr = 0, inner_l4_hdr = 0, inner_l4_hlen;
 672	struct ethhdr *eth_hdr;
 673
 674	if (skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
 675	    skb->inner_protocol != htons(ETH_P_TEB))
 676		return 0;
 677
 678	switch (vlan_get_protocol(skb)) {
 679	case htons(ETH_P_IP):
 680		l4_hdr = ip_hdr(skb)->protocol;
 681		break;
 682	case htons(ETH_P_IPV6):
 683		l4_hdr = ipv6_hdr(skb)->nexthdr;
 684		break;
 685	default:
 686		return 0;
 687	}
 688
 689	switch (l4_hdr) {
 690	case IPPROTO_UDP:
 691		eth_hdr = fm10k_port_is_vxlan(skb);
 692		break;
 693	case IPPROTO_GRE:
 694		eth_hdr = fm10k_gre_is_nvgre(skb);
 695		break;
 696	default:
 697		return 0;
 698	}
 699
 700	if (!eth_hdr)
 701		return 0;
 702
 703	switch (eth_hdr->h_proto) {
 704	case htons(ETH_P_IP):
 705		inner_l4_hdr = inner_ip_hdr(skb)->protocol;
 706		break;
 707	case htons(ETH_P_IPV6):
 708		inner_l4_hdr = inner_ipv6_hdr(skb)->nexthdr;
 709		break;
 710	default:
 711		return 0;
 712	}
 713
 714	switch (inner_l4_hdr) {
 715	case IPPROTO_TCP:
 716		inner_l4_hlen = inner_tcp_hdrlen(skb);
 717		break;
 718	case IPPROTO_UDP:
 719		inner_l4_hlen = 8;
 720		break;
 721	default:
 722		return 0;
 723	}
 724
 725	/* The hardware allows tunnel offloads only if the combined inner and
 726	 * outer header is 184 bytes or less
 727	 */
 728	if (skb_inner_transport_header(skb) + inner_l4_hlen -
 729	    skb_mac_header(skb) > FM10K_TUNNEL_HEADER_LENGTH)
 730		return 0;
 731
 732	return eth_hdr->h_proto;
 733}
 734
 735static int fm10k_tso(struct fm10k_ring *tx_ring,
 736		     struct fm10k_tx_buffer *first)
 737{
 738	struct sk_buff *skb = first->skb;
 739	struct fm10k_tx_desc *tx_desc;
 740	unsigned char *th;
 741	u8 hdrlen;
 742
 743	if (skb->ip_summed != CHECKSUM_PARTIAL)
 744		return 0;
 745
 746	if (!skb_is_gso(skb))
 747		return 0;
 748
 749	/* compute header lengths */
 750	if (skb->encapsulation) {
 751		if (!fm10k_tx_encap_offload(skb))
 752			goto err_vxlan;
 753		th = skb_inner_transport_header(skb);
 754	} else {
 755		th = skb_transport_header(skb);
 756	}
 757
 758	/* compute offset from SOF to transport header and add header len */
 759	hdrlen = (th - skb->data) + (((struct tcphdr *)th)->doff << 2);
 760
 761	first->tx_flags |= FM10K_TX_FLAGS_CSUM;
 762
 763	/* update gso size and bytecount with header size */
 764	first->gso_segs = skb_shinfo(skb)->gso_segs;
 765	first->bytecount += (first->gso_segs - 1) * hdrlen;
 766
 767	/* populate Tx descriptor header size and mss */
 768	tx_desc = FM10K_TX_DESC(tx_ring, tx_ring->next_to_use);
 769	tx_desc->hdrlen = hdrlen;
 770	tx_desc->mss = cpu_to_le16(skb_shinfo(skb)->gso_size);
 771
 772	return 1;
 773
 774err_vxlan:
 775	tx_ring->netdev->features &= ~NETIF_F_GSO_UDP_TUNNEL;
 776	if (net_ratelimit())
 777		netdev_err(tx_ring->netdev,
 778			   "TSO requested for unsupported tunnel, disabling offload\n");
 779	return -1;
 780}
 781
 782static void fm10k_tx_csum(struct fm10k_ring *tx_ring,
 783			  struct fm10k_tx_buffer *first)
 784{
 785	struct sk_buff *skb = first->skb;
 786	struct fm10k_tx_desc *tx_desc;
 787	union {
 788		struct iphdr *ipv4;
 789		struct ipv6hdr *ipv6;
 790		u8 *raw;
 791	} network_hdr;
 792	u8 *transport_hdr;
 793	__be16 frag_off;
 794	__be16 protocol;
 795	u8 l4_hdr = 0;
 796
 797	if (skb->ip_summed != CHECKSUM_PARTIAL)
 798		goto no_csum;
 799
 800	if (skb->encapsulation) {
 801		protocol = fm10k_tx_encap_offload(skb);
 802		if (!protocol) {
 803			if (skb_checksum_help(skb)) {
 804				dev_warn(tx_ring->dev,
 805					 "failed to offload encap csum!\n");
 806				tx_ring->tx_stats.csum_err++;
 807			}
 808			goto no_csum;
 809		}
 810		network_hdr.raw = skb_inner_network_header(skb);
 811		transport_hdr = skb_inner_transport_header(skb);
 812	} else {
 813		protocol = vlan_get_protocol(skb);
 814		network_hdr.raw = skb_network_header(skb);
 815		transport_hdr = skb_transport_header(skb);
 816	}
 817
 818	switch (protocol) {
 819	case htons(ETH_P_IP):
 820		l4_hdr = network_hdr.ipv4->protocol;
 821		break;
 822	case htons(ETH_P_IPV6):
 823		l4_hdr = network_hdr.ipv6->nexthdr;
 824		if (likely((transport_hdr - network_hdr.raw) ==
 825			   sizeof(struct ipv6hdr)))
 826			break;
 827		ipv6_skip_exthdr(skb, network_hdr.raw - skb->data +
 828				      sizeof(struct ipv6hdr),
 829				 &l4_hdr, &frag_off);
 830		if (unlikely(frag_off))
 831			l4_hdr = NEXTHDR_FRAGMENT;
 832		break;
 833	default:
 834		break;
 835	}
 836
 837	switch (l4_hdr) {
 838	case IPPROTO_TCP:
 839	case IPPROTO_UDP:
 840		break;
 841	case IPPROTO_GRE:
 842		if (skb->encapsulation)
 843			break;
 844		fallthrough;
 845	default:
 846		if (unlikely(net_ratelimit())) {
 847			dev_warn(tx_ring->dev,
 848				 "partial checksum, version=%d l4 proto=%x\n",
 849				 protocol, l4_hdr);
 850		}
 851		skb_checksum_help(skb);
 852		tx_ring->tx_stats.csum_err++;
 853		goto no_csum;
 854	}
 855
 856	/* update TX checksum flag */
 857	first->tx_flags |= FM10K_TX_FLAGS_CSUM;
 858	tx_ring->tx_stats.csum_good++;
 859
 860no_csum:
 861	/* populate Tx descriptor header size and mss */
 862	tx_desc = FM10K_TX_DESC(tx_ring, tx_ring->next_to_use);
 863	tx_desc->hdrlen = 0;
 864	tx_desc->mss = 0;
 865}
 866
 867#define FM10K_SET_FLAG(_input, _flag, _result) \
 868	((_flag <= _result) ? \
 869	 ((u32)(_input & _flag) * (_result / _flag)) : \
 870	 ((u32)(_input & _flag) / (_flag / _result)))
 871
 872static u8 fm10k_tx_desc_flags(struct sk_buff *skb, u32 tx_flags)
 873{
 874	/* set type for advanced descriptor with frame checksum insertion */
 875	u32 desc_flags = 0;
 876
 877	/* set checksum offload bits */
 878	desc_flags |= FM10K_SET_FLAG(tx_flags, FM10K_TX_FLAGS_CSUM,
 879				     FM10K_TXD_FLAG_CSUM);
 880
 881	return desc_flags;
 882}
 883
 884static bool fm10k_tx_desc_push(struct fm10k_ring *tx_ring,
 885			       struct fm10k_tx_desc *tx_desc, u16 i,
 886			       dma_addr_t dma, unsigned int size, u8 desc_flags)
 887{
 888	/* set RS and INT for last frame in a cache line */
 889	if ((++i & (FM10K_TXD_WB_FIFO_SIZE - 1)) == 0)
 890		desc_flags |= FM10K_TXD_FLAG_RS | FM10K_TXD_FLAG_INT;
 891
 892	/* record values to descriptor */
 893	tx_desc->buffer_addr = cpu_to_le64(dma);
 894	tx_desc->flags = desc_flags;
 895	tx_desc->buflen = cpu_to_le16(size);
 896
 897	/* return true if we just wrapped the ring */
 898	return i == tx_ring->count;
 899}
 900
 901static int __fm10k_maybe_stop_tx(struct fm10k_ring *tx_ring, u16 size)
 902{
 903	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
 904
 905	/* Memory barrier before checking head and tail */
 906	smp_mb();
 907
 908	/* Check again in a case another CPU has just made room available */
 909	if (likely(fm10k_desc_unused(tx_ring) < size))
 910		return -EBUSY;
 911
 912	/* A reprieve! - use start_queue because it doesn't call schedule */
 913	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
 914	++tx_ring->tx_stats.restart_queue;
 915	return 0;
 916}
 917
 918static inline int fm10k_maybe_stop_tx(struct fm10k_ring *tx_ring, u16 size)
 919{
 920	if (likely(fm10k_desc_unused(tx_ring) >= size))
 921		return 0;
 922	return __fm10k_maybe_stop_tx(tx_ring, size);
 923}
 924
 925static void fm10k_tx_map(struct fm10k_ring *tx_ring,
 926			 struct fm10k_tx_buffer *first)
 927{
 928	struct sk_buff *skb = first->skb;
 929	struct fm10k_tx_buffer *tx_buffer;
 930	struct fm10k_tx_desc *tx_desc;
 931	skb_frag_t *frag;
 932	unsigned char *data;
 933	dma_addr_t dma;
 934	unsigned int data_len, size;
 935	u32 tx_flags = first->tx_flags;
 936	u16 i = tx_ring->next_to_use;
 937	u8 flags = fm10k_tx_desc_flags(skb, tx_flags);
 938
 939	tx_desc = FM10K_TX_DESC(tx_ring, i);
 940
 941	/* add HW VLAN tag */
 942	if (skb_vlan_tag_present(skb))
 943		tx_desc->vlan = cpu_to_le16(skb_vlan_tag_get(skb));
 944	else
 945		tx_desc->vlan = 0;
 946
 947	size = skb_headlen(skb);
 948	data = skb->data;
 949
 950	dma = dma_map_single(tx_ring->dev, data, size, DMA_TO_DEVICE);
 951
 952	data_len = skb->data_len;
 953	tx_buffer = first;
 954
 955	for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
 956		if (dma_mapping_error(tx_ring->dev, dma))
 957			goto dma_error;
 958
 959		/* record length, and DMA address */
 960		dma_unmap_len_set(tx_buffer, len, size);
 961		dma_unmap_addr_set(tx_buffer, dma, dma);
 962
 963		while (unlikely(size > FM10K_MAX_DATA_PER_TXD)) {
 964			if (fm10k_tx_desc_push(tx_ring, tx_desc++, i++, dma,
 965					       FM10K_MAX_DATA_PER_TXD, flags)) {
 966				tx_desc = FM10K_TX_DESC(tx_ring, 0);
 967				i = 0;
 968			}
 969
 970			dma += FM10K_MAX_DATA_PER_TXD;
 971			size -= FM10K_MAX_DATA_PER_TXD;
 972		}
 973
 974		if (likely(!data_len))
 975			break;
 976
 977		if (fm10k_tx_desc_push(tx_ring, tx_desc++, i++,
 978				       dma, size, flags)) {
 979			tx_desc = FM10K_TX_DESC(tx_ring, 0);
 980			i = 0;
 981		}
 982
 983		size = skb_frag_size(frag);
 984		data_len -= size;
 985
 986		dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
 987				       DMA_TO_DEVICE);
 988
 989		tx_buffer = &tx_ring->tx_buffer[i];
 990	}
 991
 992	/* write last descriptor with LAST bit set */
 993	flags |= FM10K_TXD_FLAG_LAST;
 994
 995	if (fm10k_tx_desc_push(tx_ring, tx_desc, i++, dma, size, flags))
 996		i = 0;
 997
 998	/* record bytecount for BQL */
 999	netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);
1000
1001	/* record SW timestamp if HW timestamp is not available */
1002	skb_tx_timestamp(first->skb);
1003
1004	/* Force memory writes to complete before letting h/w know there
1005	 * are new descriptors to fetch.  (Only applicable for weak-ordered
1006	 * memory model archs, such as IA-64).
1007	 *
1008	 * We also need this memory barrier to make certain all of the
1009	 * status bits have been updated before next_to_watch is written.
1010	 */
1011	wmb();
1012
1013	/* set next_to_watch value indicating a packet is present */
1014	first->next_to_watch = tx_desc;
1015
1016	tx_ring->next_to_use = i;
1017
1018	/* Make sure there is space in the ring for the next send. */
1019	fm10k_maybe_stop_tx(tx_ring, DESC_NEEDED);
1020
1021	/* notify HW of packet */
1022	if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) {
1023		writel(i, tx_ring->tail);
1024	}
1025
1026	return;
1027dma_error:
1028	dev_err(tx_ring->dev, "TX DMA map failed\n");
1029
1030	/* clear dma mappings for failed tx_buffer map */
1031	for (;;) {
1032		tx_buffer = &tx_ring->tx_buffer[i];
1033		fm10k_unmap_and_free_tx_resource(tx_ring, tx_buffer);
1034		if (tx_buffer == first)
1035			break;
1036		if (i == 0)
1037			i = tx_ring->count;
1038		i--;
1039	}
1040
1041	tx_ring->next_to_use = i;
1042}
1043
1044netdev_tx_t fm10k_xmit_frame_ring(struct sk_buff *skb,
1045				  struct fm10k_ring *tx_ring)
1046{
1047	u16 count = TXD_USE_COUNT(skb_headlen(skb));
1048	struct fm10k_tx_buffer *first;
1049	unsigned short f;
1050	u32 tx_flags = 0;
1051	int tso;
1052
1053	/* need: 1 descriptor per page * PAGE_SIZE/FM10K_MAX_DATA_PER_TXD,
1054	 *       + 1 desc for skb_headlen/FM10K_MAX_DATA_PER_TXD,
1055	 *       + 2 desc gap to keep tail from touching head
1056	 * otherwise try next time
1057	 */
1058	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
1059		skb_frag_t *frag = &skb_shinfo(skb)->frags[f];
1060
1061		count += TXD_USE_COUNT(skb_frag_size(frag));
1062	}
1063
1064	if (fm10k_maybe_stop_tx(tx_ring, count + 3)) {
1065		tx_ring->tx_stats.tx_busy++;
1066		return NETDEV_TX_BUSY;
1067	}
1068
1069	/* record the location of the first descriptor for this packet */
1070	first = &tx_ring->tx_buffer[tx_ring->next_to_use];
1071	first->skb = skb;
1072	first->bytecount = max_t(unsigned int, skb->len, ETH_ZLEN);
1073	first->gso_segs = 1;
1074
1075	/* record initial flags and protocol */
1076	first->tx_flags = tx_flags;
1077
1078	tso = fm10k_tso(tx_ring, first);
1079	if (tso < 0)
1080		goto out_drop;
1081	else if (!tso)
1082		fm10k_tx_csum(tx_ring, first);
1083
1084	fm10k_tx_map(tx_ring, first);
1085
1086	return NETDEV_TX_OK;
1087
1088out_drop:
1089	dev_kfree_skb_any(first->skb);
1090	first->skb = NULL;
1091
1092	return NETDEV_TX_OK;
1093}
1094
1095static u64 fm10k_get_tx_completed(struct fm10k_ring *ring)
1096{
1097	return ring->stats.packets;
1098}
1099
1100/**
1101 * fm10k_get_tx_pending - how many Tx descriptors not processed
1102 * @ring: the ring structure
1103 * @in_sw: is tx_pending being checked in SW or in HW?
1104 */
1105u64 fm10k_get_tx_pending(struct fm10k_ring *ring, bool in_sw)
1106{
1107	struct fm10k_intfc *interface = ring->q_vector->interface;
1108	struct fm10k_hw *hw = &interface->hw;
1109	u32 head, tail;
1110
1111	if (likely(in_sw)) {
1112		head = ring->next_to_clean;
1113		tail = ring->next_to_use;
1114	} else {
1115		head = fm10k_read_reg(hw, FM10K_TDH(ring->reg_idx));
1116		tail = fm10k_read_reg(hw, FM10K_TDT(ring->reg_idx));
1117	}
1118
1119	return ((head <= tail) ? tail : tail + ring->count) - head;
1120}
1121
1122bool fm10k_check_tx_hang(struct fm10k_ring *tx_ring)
1123{
1124	u32 tx_done = fm10k_get_tx_completed(tx_ring);
1125	u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
1126	u32 tx_pending = fm10k_get_tx_pending(tx_ring, true);
1127
1128	clear_check_for_tx_hang(tx_ring);
1129
1130	/* Check for a hung queue, but be thorough. This verifies
1131	 * that a transmit has been completed since the previous
1132	 * check AND there is at least one packet pending. By
1133	 * requiring this to fail twice we avoid races with
1134	 * clearing the ARMED bit and conditions where we
1135	 * run the check_tx_hang logic with a transmit completion
1136	 * pending but without time to complete it yet.
1137	 */
1138	if (!tx_pending || (tx_done_old != tx_done)) {
1139		/* update completed stats and continue */
1140		tx_ring->tx_stats.tx_done_old = tx_done;
1141		/* reset the countdown */
1142		clear_bit(__FM10K_HANG_CHECK_ARMED, tx_ring->state);
1143
1144		return false;
1145	}
1146
1147	/* make sure it is true for two checks in a row */
1148	return test_and_set_bit(__FM10K_HANG_CHECK_ARMED, tx_ring->state);
1149}
1150
1151/**
1152 * fm10k_tx_timeout_reset - initiate reset due to Tx timeout
1153 * @interface: driver private struct
1154 **/
1155void fm10k_tx_timeout_reset(struct fm10k_intfc *interface)
1156{
1157	/* Do the reset outside of interrupt context */
1158	if (!test_bit(__FM10K_DOWN, interface->state)) {
1159		interface->tx_timeout_count++;
1160		set_bit(FM10K_FLAG_RESET_REQUESTED, interface->flags);
1161		fm10k_service_event_schedule(interface);
1162	}
1163}
1164
1165/**
1166 * fm10k_clean_tx_irq - Reclaim resources after transmit completes
1167 * @q_vector: structure containing interrupt and ring information
1168 * @tx_ring: tx ring to clean
1169 * @napi_budget: Used to determine if we are in netpoll
1170 **/
1171static bool fm10k_clean_tx_irq(struct fm10k_q_vector *q_vector,
1172			       struct fm10k_ring *tx_ring, int napi_budget)
1173{
1174	struct fm10k_intfc *interface = q_vector->interface;
1175	struct fm10k_tx_buffer *tx_buffer;
1176	struct fm10k_tx_desc *tx_desc;
1177	unsigned int total_bytes = 0, total_packets = 0;
1178	unsigned int budget = q_vector->tx.work_limit;
1179	unsigned int i = tx_ring->next_to_clean;
1180
1181	if (test_bit(__FM10K_DOWN, interface->state))
1182		return true;
1183
1184	tx_buffer = &tx_ring->tx_buffer[i];
1185	tx_desc = FM10K_TX_DESC(tx_ring, i);
1186	i -= tx_ring->count;
1187
1188	do {
1189		struct fm10k_tx_desc *eop_desc = tx_buffer->next_to_watch;
1190
1191		/* if next_to_watch is not set then there is no work pending */
1192		if (!eop_desc)
1193			break;
1194
1195		/* prevent any other reads prior to eop_desc */
1196		smp_rmb();
1197
1198		/* if DD is not set pending work has not been completed */
1199		if (!(eop_desc->flags & FM10K_TXD_FLAG_DONE))
1200			break;
1201
1202		/* clear next_to_watch to prevent false hangs */
1203		tx_buffer->next_to_watch = NULL;
1204
1205		/* update the statistics for this packet */
1206		total_bytes += tx_buffer->bytecount;
1207		total_packets += tx_buffer->gso_segs;
1208
1209		/* free the skb */
1210		napi_consume_skb(tx_buffer->skb, napi_budget);
1211
1212		/* unmap skb header data */
1213		dma_unmap_single(tx_ring->dev,
1214				 dma_unmap_addr(tx_buffer, dma),
1215				 dma_unmap_len(tx_buffer, len),
1216				 DMA_TO_DEVICE);
1217
1218		/* clear tx_buffer data */
1219		tx_buffer->skb = NULL;
1220		dma_unmap_len_set(tx_buffer, len, 0);
1221
1222		/* unmap remaining buffers */
1223		while (tx_desc != eop_desc) {
1224			tx_buffer++;
1225			tx_desc++;
1226			i++;
1227			if (unlikely(!i)) {
1228				i -= tx_ring->count;
1229				tx_buffer = tx_ring->tx_buffer;
1230				tx_desc = FM10K_TX_DESC(tx_ring, 0);
1231			}
1232
1233			/* unmap any remaining paged data */
1234			if (dma_unmap_len(tx_buffer, len)) {
1235				dma_unmap_page(tx_ring->dev,
1236					       dma_unmap_addr(tx_buffer, dma),
1237					       dma_unmap_len(tx_buffer, len),
1238					       DMA_TO_DEVICE);
1239				dma_unmap_len_set(tx_buffer, len, 0);
1240			}
1241		}
1242
1243		/* move us one more past the eop_desc for start of next pkt */
1244		tx_buffer++;
1245		tx_desc++;
1246		i++;
1247		if (unlikely(!i)) {
1248			i -= tx_ring->count;
1249			tx_buffer = tx_ring->tx_buffer;
1250			tx_desc = FM10K_TX_DESC(tx_ring, 0);
1251		}
1252
1253		/* issue prefetch for next Tx descriptor */
1254		prefetch(tx_desc);
1255
1256		/* update budget accounting */
1257		budget--;
1258	} while (likely(budget));
1259
1260	i += tx_ring->count;
1261	tx_ring->next_to_clean = i;
1262	u64_stats_update_begin(&tx_ring->syncp);
1263	tx_ring->stats.bytes += total_bytes;
1264	tx_ring->stats.packets += total_packets;
1265	u64_stats_update_end(&tx_ring->syncp);
1266	q_vector->tx.total_bytes += total_bytes;
1267	q_vector->tx.total_packets += total_packets;
1268
1269	if (check_for_tx_hang(tx_ring) && fm10k_check_tx_hang(tx_ring)) {
1270		/* schedule immediate reset if we believe we hung */
1271		struct fm10k_hw *hw = &interface->hw;
1272
1273		netif_err(interface, drv, tx_ring->netdev,
1274			  "Detected Tx Unit Hang\n"
1275			  "  Tx Queue             <%d>\n"
1276			  "  TDH, TDT             <%x>, <%x>\n"
1277			  "  next_to_use          <%x>\n"
1278			  "  next_to_clean        <%x>\n",
1279			  tx_ring->queue_index,
1280			  fm10k_read_reg(hw, FM10K_TDH(tx_ring->reg_idx)),
1281			  fm10k_read_reg(hw, FM10K_TDT(tx_ring->reg_idx)),
1282			  tx_ring->next_to_use, i);
1283
1284		netif_stop_subqueue(tx_ring->netdev,
1285				    tx_ring->queue_index);
1286
1287		netif_info(interface, probe, tx_ring->netdev,
1288			   "tx hang %d detected on queue %d, resetting interface\n",
1289			   interface->tx_timeout_count + 1,
1290			   tx_ring->queue_index);
1291
1292		fm10k_tx_timeout_reset(interface);
1293
1294		/* the netdev is about to reset, no point in enabling stuff */
1295		return true;
1296	}
1297
1298	/* notify netdev of completed buffers */
1299	netdev_tx_completed_queue(txring_txq(tx_ring),
1300				  total_packets, total_bytes);
1301
1302#define TX_WAKE_THRESHOLD min_t(u16, FM10K_MIN_TXD - 1, DESC_NEEDED * 2)
1303	if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
1304		     (fm10k_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD))) {
1305		/* Make sure that anybody stopping the queue after this
1306		 * sees the new next_to_clean.
1307		 */
1308		smp_mb();
1309		if (__netif_subqueue_stopped(tx_ring->netdev,
1310					     tx_ring->queue_index) &&
1311		    !test_bit(__FM10K_DOWN, interface->state)) {
1312			netif_wake_subqueue(tx_ring->netdev,
1313					    tx_ring->queue_index);
1314			++tx_ring->tx_stats.restart_queue;
1315		}
1316	}
1317
1318	return !!budget;
1319}
1320
1321/**
1322 * fm10k_update_itr - update the dynamic ITR value based on packet size
1323 *
1324 *      Stores a new ITR value based on strictly on packet size.  The
1325 *      divisors and thresholds used by this function were determined based
1326 *      on theoretical maximum wire speed and testing data, in order to
1327 *      minimize response time while increasing bulk throughput.
1328 *
1329 * @ring_container: Container for rings to have ITR updated
1330 **/
1331static void fm10k_update_itr(struct fm10k_ring_container *ring_container)
1332{
1333	unsigned int avg_wire_size, packets, itr_round;
1334
1335	/* Only update ITR if we are using adaptive setting */
1336	if (!ITR_IS_ADAPTIVE(ring_container->itr))
1337		goto clear_counts;
1338
1339	packets = ring_container->total_packets;
1340	if (!packets)
1341		goto clear_counts;
1342
1343	avg_wire_size = ring_container->total_bytes / packets;
1344
1345	/* The following is a crude approximation of:
1346	 *  wmem_default / (size + overhead) = desired_pkts_per_int
1347	 *  rate / bits_per_byte / (size + ethernet overhead) = pkt_rate
1348	 *  (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value
1349	 *
1350	 * Assuming wmem_default is 212992 and overhead is 640 bytes per
1351	 * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the
1352	 * formula down to
1353	 *
1354	 *  (34 * (size + 24)) / (size + 640) = ITR
1355	 *
1356	 * We first do some math on the packet size and then finally bitshift
1357	 * by 8 after rounding up. We also have to account for PCIe link speed
1358	 * difference as ITR scales based on this.
1359	 */
1360	if (avg_wire_size <= 360) {
1361		/* Start at 250K ints/sec and gradually drop to 77K ints/sec */
1362		avg_wire_size *= 8;
1363		avg_wire_size += 376;
1364	} else if (avg_wire_size <= 1152) {
1365		/* 77K ints/sec to 45K ints/sec */
1366		avg_wire_size *= 3;
1367		avg_wire_size += 2176;
1368	} else if (avg_wire_size <= 1920) {
1369		/* 45K ints/sec to 38K ints/sec */
1370		avg_wire_size += 4480;
1371	} else {
1372		/* plateau at a limit of 38K ints/sec */
1373		avg_wire_size = 6656;
1374	}
1375
1376	/* Perform final bitshift for division after rounding up to ensure
1377	 * that the calculation will never get below a 1. The bit shift
1378	 * accounts for changes in the ITR due to PCIe link speed.
1379	 */
1380	itr_round = READ_ONCE(ring_container->itr_scale) + 8;
1381	avg_wire_size += BIT(itr_round) - 1;
1382	avg_wire_size >>= itr_round;
1383
1384	/* write back value and retain adaptive flag */
1385	ring_container->itr = avg_wire_size | FM10K_ITR_ADAPTIVE;
1386
1387clear_counts:
1388	ring_container->total_bytes = 0;
1389	ring_container->total_packets = 0;
1390}
1391
1392static void fm10k_qv_enable(struct fm10k_q_vector *q_vector)
1393{
1394	/* Enable auto-mask and clear the current mask */
1395	u32 itr = FM10K_ITR_ENABLE;
1396
1397	/* Update Tx ITR */
1398	fm10k_update_itr(&q_vector->tx);
1399
1400	/* Update Rx ITR */
1401	fm10k_update_itr(&q_vector->rx);
1402
1403	/* Store Tx itr in timer slot 0 */
1404	itr |= (q_vector->tx.itr & FM10K_ITR_MAX);
1405
1406	/* Shift Rx itr to timer slot 1 */
1407	itr |= (q_vector->rx.itr & FM10K_ITR_MAX) << FM10K_ITR_INTERVAL1_SHIFT;
1408
1409	/* Write the final value to the ITR register */
1410	writel(itr, q_vector->itr);
1411}
1412
1413static int fm10k_poll(struct napi_struct *napi, int budget)
1414{
1415	struct fm10k_q_vector *q_vector =
1416			       container_of(napi, struct fm10k_q_vector, napi);
1417	struct fm10k_ring *ring;
1418	int per_ring_budget, work_done = 0;
1419	bool clean_complete = true;
1420
1421	fm10k_for_each_ring(ring, q_vector->tx) {
1422		if (!fm10k_clean_tx_irq(q_vector, ring, budget))
1423			clean_complete = false;
1424	}
1425
1426	/* Handle case where we are called by netpoll with a budget of 0 */
1427	if (budget <= 0)
1428		return budget;
1429
1430	/* attempt to distribute budget to each queue fairly, but don't
1431	 * allow the budget to go below 1 because we'll exit polling
1432	 */
1433	if (q_vector->rx.count > 1)
1434		per_ring_budget = max(budget / q_vector->rx.count, 1);
1435	else
1436		per_ring_budget = budget;
1437
1438	fm10k_for_each_ring(ring, q_vector->rx) {
1439		int work = fm10k_clean_rx_irq(q_vector, ring, per_ring_budget);
1440
1441		work_done += work;
1442		if (work >= per_ring_budget)
1443			clean_complete = false;
1444	}
1445
1446	/* If all work not completed, return budget and keep polling */
1447	if (!clean_complete)
1448		return budget;
1449
1450	/* Exit the polling mode, but don't re-enable interrupts if stack might
1451	 * poll us due to busy-polling
1452	 */
1453	if (likely(napi_complete_done(napi, work_done)))
1454		fm10k_qv_enable(q_vector);
1455
1456	return min(work_done, budget - 1);
1457}
1458
1459/**
1460 * fm10k_set_qos_queues: Allocate queues for a QOS-enabled device
1461 * @interface: board private structure to initialize
1462 *
1463 * When QoS (Quality of Service) is enabled, allocate queues for
1464 * each traffic class.  If multiqueue isn't available,then abort QoS
1465 * initialization.
1466 *
1467 * This function handles all combinations of Qos and RSS.
1468 *
1469 **/
1470static bool fm10k_set_qos_queues(struct fm10k_intfc *interface)
1471{
1472	struct net_device *dev = interface->netdev;
1473	struct fm10k_ring_feature *f;
1474	int rss_i, i;
1475	int pcs;
1476
1477	/* Map queue offset and counts onto allocated tx queues */
1478	pcs = netdev_get_num_tc(dev);
1479
1480	if (pcs <= 1)
1481		return false;
1482
1483	/* set QoS mask and indices */
1484	f = &interface->ring_feature[RING_F_QOS];
1485	f->indices = pcs;
1486	f->mask = BIT(fls(pcs - 1)) - 1;
1487
1488	/* determine the upper limit for our current DCB mode */
1489	rss_i = interface->hw.mac.max_queues / pcs;
1490	rss_i = BIT(fls(rss_i) - 1);
1491
1492	/* set RSS mask and indices */
1493	f = &interface->ring_feature[RING_F_RSS];
1494	rss_i = min_t(u16, rss_i, f->limit);
1495	f->indices = rss_i;
1496	f->mask = BIT(fls(rss_i - 1)) - 1;
1497
1498	/* configure pause class to queue mapping */
1499	for (i = 0; i < pcs; i++)
1500		netdev_set_tc_queue(dev, i, rss_i, rss_i * i);
1501
1502	interface->num_rx_queues = rss_i * pcs;
1503	interface->num_tx_queues = rss_i * pcs;
1504
1505	return true;
1506}
1507
1508/**
1509 * fm10k_set_rss_queues: Allocate queues for RSS
1510 * @interface: board private structure to initialize
1511 *
1512 * This is our "base" multiqueue mode.  RSS (Receive Side Scaling) will try
1513 * to allocate one Rx queue per CPU, and if available, one Tx queue per CPU.
1514 *
1515 **/
1516static bool fm10k_set_rss_queues(struct fm10k_intfc *interface)
1517{
1518	struct fm10k_ring_feature *f;
1519	u16 rss_i;
1520
1521	f = &interface->ring_feature[RING_F_RSS];
1522	rss_i = min_t(u16, interface->hw.mac.max_queues, f->limit);
1523
1524	/* record indices and power of 2 mask for RSS */
1525	f->indices = rss_i;
1526	f->mask = BIT(fls(rss_i - 1)) - 1;
1527
1528	interface->num_rx_queues = rss_i;
1529	interface->num_tx_queues = rss_i;
1530
1531	return true;
1532}
1533
1534/**
1535 * fm10k_set_num_queues: Allocate queues for device, feature dependent
1536 * @interface: board private structure to initialize
1537 *
1538 * This is the top level queue allocation routine.  The order here is very
1539 * important, starting with the "most" number of features turned on at once,
1540 * and ending with the smallest set of features.  This way large combinations
1541 * can be allocated if they're turned on, and smaller combinations are the
1542 * fall through conditions.
1543 *
1544 **/
1545static void fm10k_set_num_queues(struct fm10k_intfc *interface)
1546{
1547	/* Attempt to setup QoS and RSS first */
1548	if (fm10k_set_qos_queues(interface))
1549		return;
1550
1551	/* If we don't have QoS, just fallback to only RSS. */
1552	fm10k_set_rss_queues(interface);
1553}
1554
1555/**
1556 * fm10k_reset_num_queues - Reset the number of queues to zero
1557 * @interface: board private structure
1558 *
1559 * This function should be called whenever we need to reset the number of
1560 * queues after an error condition.
1561 */
1562static void fm10k_reset_num_queues(struct fm10k_intfc *interface)
1563{
1564	interface->num_tx_queues = 0;
1565	interface->num_rx_queues = 0;
1566	interface->num_q_vectors = 0;
1567}
1568
1569/**
1570 * fm10k_alloc_q_vector - Allocate memory for a single interrupt vector
1571 * @interface: board private structure to initialize
1572 * @v_count: q_vectors allocated on interface, used for ring interleaving
1573 * @v_idx: index of vector in interface struct
1574 * @txr_count: total number of Tx rings to allocate
1575 * @txr_idx: index of first Tx ring to allocate
1576 * @rxr_count: total number of Rx rings to allocate
1577 * @rxr_idx: index of first Rx ring to allocate
1578 *
1579 * We allocate one q_vector.  If allocation fails we return -ENOMEM.
1580 **/
1581static int fm10k_alloc_q_vector(struct fm10k_intfc *interface,
1582				unsigned int v_count, unsigned int v_idx,
1583				unsigned int txr_count, unsigned int txr_idx,
1584				unsigned int rxr_count, unsigned int rxr_idx)
1585{
1586	struct fm10k_q_vector *q_vector;
1587	struct fm10k_ring *ring;
1588	int ring_count;
1589
1590	ring_count = txr_count + rxr_count;
1591
1592	/* allocate q_vector and rings */
1593	q_vector = kzalloc(struct_size(q_vector, ring, ring_count), GFP_KERNEL);
1594	if (!q_vector)
1595		return -ENOMEM;
1596
1597	/* initialize NAPI */
1598	netif_napi_add(interface->netdev, &q_vector->napi,
1599		       fm10k_poll, NAPI_POLL_WEIGHT);
1600
1601	/* tie q_vector and interface together */
1602	interface->q_vector[v_idx] = q_vector;
1603	q_vector->interface = interface;
1604	q_vector->v_idx = v_idx;
1605
1606	/* initialize pointer to rings */
1607	ring = q_vector->ring;
1608
1609	/* save Tx ring container info */
1610	q_vector->tx.ring = ring;
1611	q_vector->tx.work_limit = FM10K_DEFAULT_TX_WORK;
1612	q_vector->tx.itr = interface->tx_itr;
1613	q_vector->tx.itr_scale = interface->hw.mac.itr_scale;
1614	q_vector->tx.count = txr_count;
1615
1616	while (txr_count) {
1617		/* assign generic ring traits */
1618		ring->dev = &interface->pdev->dev;
1619		ring->netdev = interface->netdev;
1620
1621		/* configure backlink on ring */
1622		ring->q_vector = q_vector;
1623
1624		/* apply Tx specific ring traits */
1625		ring->count = interface->tx_ring_count;
1626		ring->queue_index = txr_idx;
1627
1628		/* assign ring to interface */
1629		interface->tx_ring[txr_idx] = ring;
1630
1631		/* update count and index */
1632		txr_count--;
1633		txr_idx += v_count;
1634
1635		/* push pointer to next ring */
1636		ring++;
1637	}
1638
1639	/* save Rx ring container info */
1640	q_vector->rx.ring = ring;
1641	q_vector->rx.itr = interface->rx_itr;
1642	q_vector->rx.itr_scale = interface->hw.mac.itr_scale;
1643	q_vector->rx.count = rxr_count;
1644
1645	while (rxr_count) {
1646		/* assign generic ring traits */
1647		ring->dev = &interface->pdev->dev;
1648		ring->netdev = interface->netdev;
1649		rcu_assign_pointer(ring->l2_accel, interface->l2_accel);
1650
1651		/* configure backlink on ring */
1652		ring->q_vector = q_vector;
1653
1654		/* apply Rx specific ring traits */
1655		ring->count = interface->rx_ring_count;
1656		ring->queue_index = rxr_idx;
1657
1658		/* assign ring to interface */
1659		interface->rx_ring[rxr_idx] = ring;
1660
1661		/* update count and index */
1662		rxr_count--;
1663		rxr_idx += v_count;
1664
1665		/* push pointer to next ring */
1666		ring++;
1667	}
1668
1669	fm10k_dbg_q_vector_init(q_vector);
1670
1671	return 0;
1672}
1673
1674/**
1675 * fm10k_free_q_vector - Free memory allocated for specific interrupt vector
1676 * @interface: board private structure to initialize
1677 * @v_idx: Index of vector to be freed
1678 *
1679 * This function frees the memory allocated to the q_vector.  In addition if
1680 * NAPI is enabled it will delete any references to the NAPI struct prior
1681 * to freeing the q_vector.
1682 **/
1683static void fm10k_free_q_vector(struct fm10k_intfc *interface, int v_idx)
1684{
1685	struct fm10k_q_vector *q_vector = interface->q_vector[v_idx];
1686	struct fm10k_ring *ring;
1687
1688	fm10k_dbg_q_vector_exit(q_vector);
1689
1690	fm10k_for_each_ring(ring, q_vector->tx)
1691		interface->tx_ring[ring->queue_index] = NULL;
1692
1693	fm10k_for_each_ring(ring, q_vector->rx)
1694		interface->rx_ring[ring->queue_index] = NULL;
1695
1696	interface->q_vector[v_idx] = NULL;
1697	netif_napi_del(&q_vector->napi);
1698	kfree_rcu(q_vector, rcu);
1699}
1700
1701/**
1702 * fm10k_alloc_q_vectors - Allocate memory for interrupt vectors
1703 * @interface: board private structure to initialize
1704 *
1705 * We allocate one q_vector per queue interrupt.  If allocation fails we
1706 * return -ENOMEM.
1707 **/
1708static int fm10k_alloc_q_vectors(struct fm10k_intfc *interface)
1709{
1710	unsigned int q_vectors = interface->num_q_vectors;
1711	unsigned int rxr_remaining = interface->num_rx_queues;
1712	unsigned int txr_remaining = interface->num_tx_queues;
1713	unsigned int rxr_idx = 0, txr_idx = 0, v_idx = 0;
1714	int err;
1715
1716	if (q_vectors >= (rxr_remaining + txr_remaining)) {
1717		for (; rxr_remaining; v_idx++) {
1718			err = fm10k_alloc_q_vector(interface, q_vectors, v_idx,
1719						   0, 0, 1, rxr_idx);
1720			if (err)
1721				goto err_out;
1722
1723			/* update counts and index */
1724			rxr_remaining--;
1725			rxr_idx++;
1726		}
1727	}
1728
1729	for (; v_idx < q_vectors; v_idx++) {
1730		int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors - v_idx);
1731		int tqpv = DIV_ROUND_UP(txr_remaining, q_vectors - v_idx);
1732
1733		err = fm10k_alloc_q_vector(interface, q_vectors, v_idx,
1734					   tqpv, txr_idx,
1735					   rqpv, rxr_idx);
1736
1737		if (err)
1738			goto err_out;
1739
1740		/* update counts and index */
1741		rxr_remaining -= rqpv;
1742		txr_remaining -= tqpv;
1743		rxr_idx++;
1744		txr_idx++;
1745	}
1746
1747	return 0;
1748
1749err_out:
1750	fm10k_reset_num_queues(interface);
1751
1752	while (v_idx--)
1753		fm10k_free_q_vector(interface, v_idx);
1754
1755	return -ENOMEM;
1756}
1757
1758/**
1759 * fm10k_free_q_vectors - Free memory allocated for interrupt vectors
1760 * @interface: board private structure to initialize
1761 *
1762 * This function frees the memory allocated to the q_vectors.  In addition if
1763 * NAPI is enabled it will delete any references to the NAPI struct prior
1764 * to freeing the q_vector.
1765 **/
1766static void fm10k_free_q_vectors(struct fm10k_intfc *interface)
1767{
1768	int v_idx = interface->num_q_vectors;
1769
1770	fm10k_reset_num_queues(interface);
1771
1772	while (v_idx--)
1773		fm10k_free_q_vector(interface, v_idx);
1774}
1775
1776/**
1777 * fm10k_reset_msix_capability - reset MSI-X capability
1778 * @interface: board private structure to initialize
1779 *
1780 * Reset the MSI-X capability back to its starting state
1781 **/
1782static void fm10k_reset_msix_capability(struct fm10k_intfc *interface)
1783{
1784	pci_disable_msix(interface->pdev);
1785	kfree(interface->msix_entries);
1786	interface->msix_entries = NULL;
1787}
1788
1789/**
1790 * fm10k_init_msix_capability - configure MSI-X capability
1791 * @interface: board private structure to initialize
1792 *
1793 * Attempt to configure the interrupts using the best available
1794 * capabilities of the hardware and the kernel.
1795 **/
1796static int fm10k_init_msix_capability(struct fm10k_intfc *interface)
1797{
1798	struct fm10k_hw *hw = &interface->hw;
1799	int v_budget, vector;
1800
1801	/* It's easy to be greedy for MSI-X vectors, but it really
1802	 * doesn't do us much good if we have a lot more vectors
1803	 * than CPU's.  So let's be conservative and only ask for
1804	 * (roughly) the same number of vectors as there are CPU's.
1805	 * the default is to use pairs of vectors
1806	 */
1807	v_budget = max(interface->num_rx_queues, interface->num_tx_queues);
1808	v_budget = min_t(u16, v_budget, num_online_cpus());
1809
1810	/* account for vectors not related to queues */
1811	v_budget += NON_Q_VECTORS;
1812
1813	/* At the same time, hardware can only support a maximum of
1814	 * hw.mac->max_msix_vectors vectors.  With features
1815	 * such as RSS and VMDq, we can easily surpass the number of Rx and Tx
1816	 * descriptor queues supported by our device.  Thus, we cap it off in
1817	 * those rare cases where the cpu count also exceeds our vector limit.
1818	 */
1819	v_budget = min_t(int, v_budget, hw->mac.max_msix_vectors);
1820
1821	/* A failure in MSI-X entry allocation is fatal. */
1822	interface->msix_entries = kcalloc(v_budget, sizeof(struct msix_entry),
1823					  GFP_KERNEL);
1824	if (!interface->msix_entries)
1825		return -ENOMEM;
1826
1827	/* populate entry values */
1828	for (vector = 0; vector < v_budget; vector++)
1829		interface->msix_entries[vector].entry = vector;
1830
1831	/* Attempt to enable MSI-X with requested value */
1832	v_budget = pci_enable_msix_range(interface->pdev,
1833					 interface->msix_entries,
1834					 MIN_MSIX_COUNT(hw),
1835					 v_budget);
1836	if (v_budget < 0) {
1837		kfree(interface->msix_entries);
1838		interface->msix_entries = NULL;
1839		return v_budget;
1840	}
1841
1842	/* record the number of queues available for q_vectors */
1843	interface->num_q_vectors = v_budget - NON_Q_VECTORS;
1844
1845	return 0;
1846}
1847
1848/**
1849 * fm10k_cache_ring_qos - Descriptor ring to register mapping for QoS
1850 * @interface: Interface structure continaining rings and devices
1851 *
1852 * Cache the descriptor ring offsets for Qos
1853 **/
1854static bool fm10k_cache_ring_qos(struct fm10k_intfc *interface)
1855{
1856	struct net_device *dev = interface->netdev;
1857	int pc, offset, rss_i, i;
1858	u16 pc_stride = interface->ring_feature[RING_F_QOS].mask + 1;
1859	u8 num_pcs = netdev_get_num_tc(dev);
1860
1861	if (num_pcs <= 1)
1862		return false;
1863
1864	rss_i = interface->ring_feature[RING_F_RSS].indices;
1865
1866	for (pc = 0, offset = 0; pc < num_pcs; pc++, offset += rss_i) {
1867		int q_idx = pc;
1868
1869		for (i = 0; i < rss_i; i++) {
1870			interface->tx_ring[offset + i]->reg_idx = q_idx;
1871			interface->tx_ring[offset + i]->qos_pc = pc;
1872			interface->rx_ring[offset + i]->reg_idx = q_idx;
1873			interface->rx_ring[offset + i]->qos_pc = pc;
1874			q_idx += pc_stride;
1875		}
1876	}
1877
1878	return true;
1879}
1880
1881/**
1882 * fm10k_cache_ring_rss - Descriptor ring to register mapping for RSS
1883 * @interface: Interface structure continaining rings and devices
1884 *
1885 * Cache the descriptor ring offsets for RSS
1886 **/
1887static void fm10k_cache_ring_rss(struct fm10k_intfc *interface)
1888{
1889	int i;
1890
1891	for (i = 0; i < interface->num_rx_queues; i++)
1892		interface->rx_ring[i]->reg_idx = i;
1893
1894	for (i = 0; i < interface->num_tx_queues; i++)
1895		interface->tx_ring[i]->reg_idx = i;
1896}
1897
1898/**
1899 * fm10k_assign_rings - Map rings to network devices
1900 * @interface: Interface structure containing rings and devices
1901 *
1902 * This function is meant to go though and configure both the network
1903 * devices so that they contain rings, and configure the rings so that
1904 * they function with their network devices.
1905 **/
1906static void fm10k_assign_rings(struct fm10k_intfc *interface)
1907{
1908	if (fm10k_cache_ring_qos(interface))
1909		return;
1910
1911	fm10k_cache_ring_rss(interface);
1912}
1913
1914static void fm10k_init_reta(struct fm10k_intfc *interface)
1915{
1916	u16 i, rss_i = interface->ring_feature[RING_F_RSS].indices;
1917	u32 reta;
1918
1919	/* If the Rx flow indirection table has been configured manually, we
1920	 * need to maintain it when possible.
1921	 */
1922	if (netif_is_rxfh_configured(interface->netdev)) {
1923		for (i = FM10K_RETA_SIZE; i--;) {
1924			reta = interface->reta[i];
1925			if ((((reta << 24) >> 24) < rss_i) &&
1926			    (((reta << 16) >> 24) < rss_i) &&
1927			    (((reta <<  8) >> 24) < rss_i) &&
1928			    (((reta)       >> 24) < rss_i))
1929				continue;
1930
1931			/* this should never happen */
1932			dev_err(&interface->pdev->dev,
1933				"RSS indirection table assigned flows out of queue bounds. Reconfiguring.\n");
1934			goto repopulate_reta;
1935		}
1936
1937		/* do nothing if all of the elements are in bounds */
1938		return;
1939	}
1940
1941repopulate_reta:
1942	fm10k_write_reta(interface, NULL);
1943}
1944
1945/**
1946 * fm10k_init_queueing_scheme - Determine proper queueing scheme
1947 * @interface: board private structure to initialize
1948 *
1949 * We determine which queueing scheme to use based on...
1950 * - Hardware queue count (num_*_queues)
1951 *   - defined by miscellaneous hardware support/features (RSS, etc.)
1952 **/
1953int fm10k_init_queueing_scheme(struct fm10k_intfc *interface)
1954{
1955	int err;
1956
1957	/* Number of supported queues */
1958	fm10k_set_num_queues(interface);
1959
1960	/* Configure MSI-X capability */
1961	err = fm10k_init_msix_capability(interface);
1962	if (err) {
1963		dev_err(&interface->pdev->dev,
1964			"Unable to initialize MSI-X capability\n");
1965		goto err_init_msix;
1966	}
1967
1968	/* Allocate memory for queues */
1969	err = fm10k_alloc_q_vectors(interface);
1970	if (err) {
1971		dev_err(&interface->pdev->dev,
1972			"Unable to allocate queue vectors\n");
1973		goto err_alloc_q_vectors;
1974	}
1975
1976	/* Map rings to devices, and map devices to physical queues */
1977	fm10k_assign_rings(interface);
1978
1979	/* Initialize RSS redirection table */
1980	fm10k_init_reta(interface);
1981
1982	return 0;
1983
1984err_alloc_q_vectors:
1985	fm10k_reset_msix_capability(interface);
1986err_init_msix:
1987	fm10k_reset_num_queues(interface);
1988	return err;
1989}
1990
1991/**
1992 * fm10k_clear_queueing_scheme - Clear the current queueing scheme settings
1993 * @interface: board private structure to clear queueing scheme on
1994 *
1995 * We go through and clear queueing specific resources and reset the structure
1996 * to pre-load conditions
1997 **/
1998void fm10k_clear_queueing_scheme(struct fm10k_intfc *interface)
1999{
2000	fm10k_free_q_vectors(interface);
2001	fm10k_reset_msix_capability(interface);
2002}