1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* Copyright(c) 2013 - 2018 Intel Corporation. */ 3 4 #ifndef _I40E_TXRX_H_ 5 #define _I40E_TXRX_H_ 6 7 #include <net/xdp.h> 8 9 /* Interrupt Throttling and Rate Limiting Goodies */ 10 #define I40E_DEFAULT_IRQ_WORK 256 11 12 /* The datasheet for the X710 and XL710 indicate that the maximum value for 13 * the ITR is 8160usec which is then called out as 0xFF0 with a 2usec 14 * resolution. 8160 is 0x1FE0 when written out in hex. So instead of storing 15 * the register value which is divided by 2 lets use the actual values and 16 * avoid an excessive amount of translation. 17 */ 18 #define I40E_ITR_DYNAMIC 0x8000 /* use top bit as a flag */ 19 #define I40E_ITR_MASK 0x1FFE /* mask for ITR register value */ 20 #define I40E_MIN_ITR 2 /* reg uses 2 usec resolution */ 21 #define I40E_ITR_20K 50 22 #define I40E_ITR_8K 122 23 #define I40E_MAX_ITR 8160 /* maximum value as per datasheet */ 24 #define ITR_TO_REG(setting) ((setting) & ~I40E_ITR_DYNAMIC) 25 #define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~I40E_ITR_MASK) 26 #define ITR_IS_DYNAMIC(setting) (!!((setting) & I40E_ITR_DYNAMIC)) 27 28 #define I40E_ITR_RX_DEF (I40E_ITR_20K | I40E_ITR_DYNAMIC) 29 #define I40E_ITR_TX_DEF (I40E_ITR_20K | I40E_ITR_DYNAMIC) 30 31 /* 0x40 is the enable bit for interrupt rate limiting, and must be set if 32 * the value of the rate limit is non-zero 33 */ 34 #define INTRL_ENA BIT(6) 35 #define I40E_MAX_INTRL 0x3B /* reg uses 4 usec resolution */ 36 #define INTRL_REG_TO_USEC(intrl) ((intrl & ~INTRL_ENA) << 2) 37 38 /** 39 * i40e_intrl_usec_to_reg - convert interrupt rate limit to register 40 * @intrl: interrupt rate limit to convert 41 * 42 * This function converts a decimal interrupt rate limit to the appropriate 43 * register format expected by the firmware when setting interrupt rate limit. 44 */ 45 static inline u16 i40e_intrl_usec_to_reg(int intrl) 46 { 47 if (intrl >> 2) 48 return ((intrl >> 2) | INTRL_ENA); 49 else 50 return 0; 51 } 52 53 #define I40E_QUEUE_END_OF_LIST 0x7FF 54 55 /* this enum matches hardware bits and is meant to be used by DYN_CTLN 56 * registers and QINT registers or more generally anywhere in the manual 57 * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any 58 * register but instead is a special value meaning "don't update" ITR0/1/2. 59 */ 60 enum i40e_dyn_idx_t { 61 I40E_IDX_ITR0 = 0, 62 I40E_IDX_ITR1 = 1, 63 I40E_IDX_ITR2 = 2, 64 I40E_ITR_NONE = 3 /* ITR_NONE must not be used as an index */ 65 }; 66 67 /* these are indexes into ITRN registers */ 68 #define I40E_RX_ITR I40E_IDX_ITR0 69 #define I40E_TX_ITR I40E_IDX_ITR1 70 71 /* Supported RSS offloads */ 72 #define I40E_DEFAULT_RSS_HENA ( \ 73 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_UDP) | \ 74 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_SCTP) | \ 75 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP) | \ 76 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_OTHER) | \ 77 BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV4) | \ 78 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_UDP) | \ 79 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP) | \ 80 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_SCTP) | \ 81 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_OTHER) | \ 82 BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV6) | \ 83 BIT_ULL(I40E_FILTER_PCTYPE_L2_PAYLOAD)) 84 85 #define I40E_DEFAULT_RSS_HENA_EXPANDED (I40E_DEFAULT_RSS_HENA | \ 86 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \ 87 BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \ 88 BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \ 89 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \ 90 BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \ 91 BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP)) 92 93 #define i40e_pf_get_default_rss_hena(pf) \ 94 (((pf)->hw_features & I40E_HW_MULTIPLE_TCP_UDP_RSS_PCTYPE) ? \ 95 I40E_DEFAULT_RSS_HENA_EXPANDED : I40E_DEFAULT_RSS_HENA) 96 97 /* Supported Rx Buffer Sizes (a multiple of 128) */ 98 #define I40E_RXBUFFER_256 256 99 #define I40E_RXBUFFER_1536 1536 /* 128B aligned standard Ethernet frame */ 100 #define I40E_RXBUFFER_2048 2048 101 #define I40E_RXBUFFER_3072 3072 /* Used for large frames w/ padding */ 102 #define I40E_MAX_RXBUFFER 9728 /* largest size for single descriptor */ 103 104 /* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we 105 * reserve 2 more, and skb_shared_info adds an additional 384 bytes more, 106 * this adds up to 512 bytes of extra data meaning the smallest allocation 107 * we could have is 1K. 108 * i.e. RXBUFFER_256 --> 960 byte skb (size-1024 slab) 109 * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab) 110 */ 111 #define I40E_RX_HDR_SIZE I40E_RXBUFFER_256 112 #define I40E_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2)) 113 #define i40e_rx_desc i40e_16byte_rx_desc 114 115 #define I40E_RX_DMA_ATTR \ 116 (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING) 117 118 /* Attempt to maximize the headroom available for incoming frames. We 119 * use a 2K buffer for receives and need 1536/1534 to store the data for 120 * the frame. This leaves us with 512 bytes of room. From that we need 121 * to deduct the space needed for the shared info and the padding needed 122 * to IP align the frame. 123 * 124 * Note: For cache line sizes 256 or larger this value is going to end 125 * up negative. In these cases we should fall back to the legacy 126 * receive path. 127 */ 128 #if (PAGE_SIZE < 8192) 129 #define I40E_2K_TOO_SMALL_WITH_PADDING \ 130 ((NET_SKB_PAD + I40E_RXBUFFER_1536) > SKB_WITH_OVERHEAD(I40E_RXBUFFER_2048)) 131 132 static inline int i40e_compute_pad(int rx_buf_len) 133 { 134 int page_size, pad_size; 135 136 page_size = ALIGN(rx_buf_len, PAGE_SIZE / 2); 137 pad_size = SKB_WITH_OVERHEAD(page_size) - rx_buf_len; 138 139 return pad_size; 140 } 141 142 static inline int i40e_skb_pad(void) 143 { 144 int rx_buf_len; 145 146 /* If a 2K buffer cannot handle a standard Ethernet frame then 147 * optimize padding for a 3K buffer instead of a 1.5K buffer. 148 * 149 * For a 3K buffer we need to add enough padding to allow for 150 * tailroom due to NET_IP_ALIGN possibly shifting us out of 151 * cache-line alignment. 152 */ 153 if (I40E_2K_TOO_SMALL_WITH_PADDING) 154 rx_buf_len = I40E_RXBUFFER_3072 + SKB_DATA_ALIGN(NET_IP_ALIGN); 155 else 156 rx_buf_len = I40E_RXBUFFER_1536; 157 158 /* if needed make room for NET_IP_ALIGN */ 159 rx_buf_len -= NET_IP_ALIGN; 160 161 return i40e_compute_pad(rx_buf_len); 162 } 163 164 #define I40E_SKB_PAD i40e_skb_pad() 165 #else 166 #define I40E_2K_TOO_SMALL_WITH_PADDING false 167 #define I40E_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN) 168 #endif 169 170 /** 171 * i40e_test_staterr - tests bits in Rx descriptor status and error fields 172 * @rx_desc: pointer to receive descriptor (in le64 format) 173 * @stat_err_bits: value to mask 174 * 175 * This function does some fast chicanery in order to return the 176 * value of the mask which is really only used for boolean tests. 177 * The status_error_len doesn't need to be shifted because it begins 178 * at offset zero. 179 */ 180 static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc, 181 const u64 stat_err_bits) 182 { 183 return !!(rx_desc->wb.qword1.status_error_len & 184 cpu_to_le64(stat_err_bits)); 185 } 186 187 /* How many Rx Buffers do we bundle into one write to the hardware ? */ 188 #define I40E_RX_BUFFER_WRITE 32 /* Must be power of 2 */ 189 190 #define I40E_RX_NEXT_DESC(r, i, n) \ 191 do { \ 192 (i)++; \ 193 if ((i) == (r)->count) \ 194 i = 0; \ 195 (n) = I40E_RX_DESC((r), (i)); \ 196 } while (0) 197 198 199 #define I40E_MAX_BUFFER_TXD 8 200 #define I40E_MIN_TX_LEN 17 201 202 /* The size limit for a transmit buffer in a descriptor is (16K - 1). 203 * In order to align with the read requests we will align the value to 204 * the nearest 4K which represents our maximum read request size. 205 */ 206 #define I40E_MAX_READ_REQ_SIZE 4096 207 #define I40E_MAX_DATA_PER_TXD (16 * 1024 - 1) 208 #define I40E_MAX_DATA_PER_TXD_ALIGNED \ 209 (I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1)) 210 211 /** 212 * i40e_txd_use_count - estimate the number of descriptors needed for Tx 213 * @size: transmit request size in bytes 214 * 215 * Due to hardware alignment restrictions (4K alignment), we need to 216 * assume that we can have no more than 12K of data per descriptor, even 217 * though each descriptor can take up to 16K - 1 bytes of aligned memory. 218 * Thus, we need to divide by 12K. But division is slow! Instead, 219 * we decompose the operation into shifts and one relatively cheap 220 * multiply operation. 221 * 222 * To divide by 12K, we first divide by 4K, then divide by 3: 223 * To divide by 4K, shift right by 12 bits 224 * To divide by 3, multiply by 85, then divide by 256 225 * (Divide by 256 is done by shifting right by 8 bits) 226 * Finally, we add one to round up. Because 256 isn't an exact multiple of 227 * 3, we'll underestimate near each multiple of 12K. This is actually more 228 * accurate as we have 4K - 1 of wiggle room that we can fit into the last 229 * segment. For our purposes this is accurate out to 1M which is orders of 230 * magnitude greater than our largest possible GSO size. 231 * 232 * This would then be implemented as: 233 * return (((size >> 12) * 85) >> 8) + 1; 234 * 235 * Since multiplication and division are commutative, we can reorder 236 * operations into: 237 * return ((size * 85) >> 20) + 1; 238 */ 239 static inline unsigned int i40e_txd_use_count(unsigned int size) 240 { 241 return ((size * 85) >> 20) + 1; 242 } 243 244 /* Tx Descriptors needed, worst case */ 245 #define DESC_NEEDED (MAX_SKB_FRAGS + 6) 246 247 #define I40E_TX_FLAGS_HW_VLAN BIT(1) 248 #define I40E_TX_FLAGS_SW_VLAN BIT(2) 249 #define I40E_TX_FLAGS_TSO BIT(3) 250 #define I40E_TX_FLAGS_IPV4 BIT(4) 251 #define I40E_TX_FLAGS_IPV6 BIT(5) 252 #define I40E_TX_FLAGS_TSYN BIT(8) 253 #define I40E_TX_FLAGS_FD_SB BIT(9) 254 #define I40E_TX_FLAGS_UDP_TUNNEL BIT(10) 255 #define I40E_TX_FLAGS_VLAN_MASK 0xffff0000 256 #define I40E_TX_FLAGS_VLAN_PRIO_MASK 0xe0000000 257 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT 29 258 #define I40E_TX_FLAGS_VLAN_SHIFT 16 259 260 struct i40e_tx_buffer { 261 struct i40e_tx_desc *next_to_watch; 262 union { 263 struct xdp_frame *xdpf; 264 struct sk_buff *skb; 265 void *raw_buf; 266 }; 267 unsigned int bytecount; 268 unsigned short gso_segs; 269 270 DEFINE_DMA_UNMAP_ADDR(dma); 271 DEFINE_DMA_UNMAP_LEN(len); 272 u32 tx_flags; 273 }; 274 275 struct i40e_rx_buffer { 276 dma_addr_t dma; 277 struct page *page; 278 __u32 page_offset; 279 __u16 pagecnt_bias; 280 }; 281 282 struct i40e_queue_stats { 283 u64 packets; 284 u64 bytes; 285 }; 286 287 struct i40e_tx_queue_stats { 288 u64 restart_queue; 289 u64 tx_busy; 290 u64 tx_done_old; 291 u64 tx_linearize; 292 u64 tx_force_wb; 293 int prev_pkt_ctr; 294 }; 295 296 struct i40e_rx_queue_stats { 297 u64 non_eop_descs; 298 u64 alloc_page_failed; 299 u64 alloc_buff_failed; 300 u64 page_reuse_count; 301 u64 page_alloc_count; 302 u64 page_waive_count; 303 u64 page_busy_count; 304 }; 305 306 enum i40e_ring_state_t { 307 __I40E_TX_FDIR_INIT_DONE, 308 __I40E_TX_XPS_INIT_DONE, 309 __I40E_RING_STATE_NBITS /* must be last */ 310 }; 311 312 /* some useful defines for virtchannel interface, which 313 * is the only remaining user of header split 314 */ 315 #define I40E_RX_DTYPE_HEADER_SPLIT 1 316 #define I40E_RX_SPLIT_L2 0x1 317 #define I40E_RX_SPLIT_IP 0x2 318 #define I40E_RX_SPLIT_TCP_UDP 0x4 319 #define I40E_RX_SPLIT_SCTP 0x8 320 321 /* struct that defines a descriptor ring, associated with a VSI */ 322 struct i40e_ring { 323 struct i40e_ring *next; /* pointer to next ring in q_vector */ 324 void *desc; /* Descriptor ring memory */ 325 struct device *dev; /* Used for DMA mapping */ 326 struct net_device *netdev; /* netdev ring maps to */ 327 struct bpf_prog *xdp_prog; 328 union { 329 struct i40e_tx_buffer *tx_bi; 330 struct i40e_rx_buffer *rx_bi; 331 struct xdp_buff **rx_bi_zc; 332 }; 333 DECLARE_BITMAP(state, __I40E_RING_STATE_NBITS); 334 u16 queue_index; /* Queue number of ring */ 335 u8 dcb_tc; /* Traffic class of ring */ 336 u8 __iomem *tail; 337 338 /* high bit set means dynamic, use accessor routines to read/write. 339 * hardware only supports 2us resolution for the ITR registers. 340 * these values always store the USER setting, and must be converted 341 * before programming to a register. 342 */ 343 u16 itr_setting; 344 345 u16 count; /* Number of descriptors */ 346 u16 reg_idx; /* HW register index of the ring */ 347 u16 rx_buf_len; 348 349 /* used in interrupt processing */ 350 u16 next_to_use; 351 u16 next_to_clean; 352 u16 xdp_tx_active; 353 354 u8 atr_sample_rate; 355 u8 atr_count; 356 357 bool ring_active; /* is ring online or not */ 358 bool arm_wb; /* do something to arm write back */ 359 u8 packet_stride; 360 361 u16 flags; 362 #define I40E_TXR_FLAGS_WB_ON_ITR BIT(0) 363 #define I40E_RXR_FLAGS_BUILD_SKB_ENABLED BIT(1) 364 #define I40E_TXR_FLAGS_XDP BIT(2) 365 366 /* stats structs */ 367 struct i40e_queue_stats stats; 368 struct u64_stats_sync syncp; 369 union { 370 struct i40e_tx_queue_stats tx_stats; 371 struct i40e_rx_queue_stats rx_stats; 372 }; 373 374 unsigned int size; /* length of descriptor ring in bytes */ 375 dma_addr_t dma; /* physical address of ring */ 376 377 struct i40e_vsi *vsi; /* Backreference to associated VSI */ 378 struct i40e_q_vector *q_vector; /* Backreference to associated vector */ 379 380 struct rcu_head rcu; /* to avoid race on free */ 381 u16 next_to_alloc; 382 struct sk_buff *skb; /* When i40e_clean_rx_ring_irq() must 383 * return before it sees the EOP for 384 * the current packet, we save that skb 385 * here and resume receiving this 386 * packet the next time 387 * i40e_clean_rx_ring_irq() is called 388 * for this ring. 389 */ 390 391 struct i40e_channel *ch; 392 u16 rx_offset; 393 struct xdp_rxq_info xdp_rxq; 394 struct xsk_buff_pool *xsk_pool; 395 } ____cacheline_internodealigned_in_smp; 396 397 static inline bool ring_uses_build_skb(struct i40e_ring *ring) 398 { 399 return !!(ring->flags & I40E_RXR_FLAGS_BUILD_SKB_ENABLED); 400 } 401 402 static inline void set_ring_build_skb_enabled(struct i40e_ring *ring) 403 { 404 ring->flags |= I40E_RXR_FLAGS_BUILD_SKB_ENABLED; 405 } 406 407 static inline void clear_ring_build_skb_enabled(struct i40e_ring *ring) 408 { 409 ring->flags &= ~I40E_RXR_FLAGS_BUILD_SKB_ENABLED; 410 } 411 412 static inline bool ring_is_xdp(struct i40e_ring *ring) 413 { 414 return !!(ring->flags & I40E_TXR_FLAGS_XDP); 415 } 416 417 static inline void set_ring_xdp(struct i40e_ring *ring) 418 { 419 ring->flags |= I40E_TXR_FLAGS_XDP; 420 } 421 422 #define I40E_ITR_ADAPTIVE_MIN_INC 0x0002 423 #define I40E_ITR_ADAPTIVE_MIN_USECS 0x0002 424 #define I40E_ITR_ADAPTIVE_MAX_USECS 0x007e 425 #define I40E_ITR_ADAPTIVE_LATENCY 0x8000 426 #define I40E_ITR_ADAPTIVE_BULK 0x0000 427 428 struct i40e_ring_container { 429 struct i40e_ring *ring; /* pointer to linked list of ring(s) */ 430 unsigned long next_update; /* jiffies value of next update */ 431 unsigned int total_bytes; /* total bytes processed this int */ 432 unsigned int total_packets; /* total packets processed this int */ 433 u16 count; 434 u16 target_itr; /* target ITR setting for ring(s) */ 435 u16 current_itr; /* current ITR setting for ring(s) */ 436 }; 437 438 /* iterator for handling rings in ring container */ 439 #define i40e_for_each_ring(pos, head) \ 440 for (pos = (head).ring; pos != NULL; pos = pos->next) 441 442 static inline unsigned int i40e_rx_pg_order(struct i40e_ring *ring) 443 { 444 #if (PAGE_SIZE < 8192) 445 if (ring->rx_buf_len > (PAGE_SIZE / 2)) 446 return 1; 447 #endif 448 return 0; 449 } 450 451 #define i40e_rx_pg_size(_ring) (PAGE_SIZE << i40e_rx_pg_order(_ring)) 452 453 bool i40e_alloc_rx_buffers(struct i40e_ring *rxr, u16 cleaned_count); 454 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev); 455 u16 i40e_lan_select_queue(struct net_device *netdev, struct sk_buff *skb, 456 struct net_device *sb_dev); 457 void i40e_clean_tx_ring(struct i40e_ring *tx_ring); 458 void i40e_clean_rx_ring(struct i40e_ring *rx_ring); 459 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring); 460 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring); 461 void i40e_free_tx_resources(struct i40e_ring *tx_ring); 462 void i40e_free_rx_resources(struct i40e_ring *rx_ring); 463 int i40e_napi_poll(struct napi_struct *napi, int budget); 464 void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector); 465 u32 i40e_get_tx_pending(struct i40e_ring *ring, bool in_sw); 466 void i40e_detect_recover_hung(struct i40e_vsi *vsi); 467 int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size); 468 bool __i40e_chk_linearize(struct sk_buff *skb); 469 int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, 470 u32 flags); 471 int i40e_alloc_rx_bi(struct i40e_ring *rx_ring); 472 473 /** 474 * i40e_get_head - Retrieve head from head writeback 475 * @tx_ring: tx ring to fetch head of 476 * 477 * Returns value of Tx ring head based on value stored 478 * in head write-back location 479 **/ 480 static inline u32 i40e_get_head(struct i40e_ring *tx_ring) 481 { 482 void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count; 483 484 return le32_to_cpu(*(volatile __le32 *)head); 485 } 486 487 /** 488 * i40e_xmit_descriptor_count - calculate number of Tx descriptors needed 489 * @skb: send buffer 490 * 491 * Returns number of data descriptors needed for this skb. Returns 0 to indicate 492 * there is not enough descriptors available in this ring since we need at least 493 * one descriptor. 494 **/ 495 static inline int i40e_xmit_descriptor_count(struct sk_buff *skb) 496 { 497 const skb_frag_t *frag = &skb_shinfo(skb)->frags[0]; 498 unsigned int nr_frags = skb_shinfo(skb)->nr_frags; 499 int count = 0, size = skb_headlen(skb); 500 501 for (;;) { 502 count += i40e_txd_use_count(size); 503 504 if (!nr_frags--) 505 break; 506 507 size = skb_frag_size(frag++); 508 } 509 510 return count; 511 } 512 513 /** 514 * i40e_maybe_stop_tx - 1st level check for Tx stop conditions 515 * @tx_ring: the ring to be checked 516 * @size: the size buffer we want to assure is available 517 * 518 * Returns 0 if stop is not needed 519 **/ 520 static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size) 521 { 522 if (likely(I40E_DESC_UNUSED(tx_ring) >= size)) 523 return 0; 524 return __i40e_maybe_stop_tx(tx_ring, size); 525 } 526 527 /** 528 * i40e_chk_linearize - Check if there are more than 8 fragments per packet 529 * @skb: send buffer 530 * @count: number of buffers used 531 * 532 * Note: Our HW can't scatter-gather more than 8 fragments to build 533 * a packet on the wire and so we need to figure out the cases where we 534 * need to linearize the skb. 535 **/ 536 static inline bool i40e_chk_linearize(struct sk_buff *skb, int count) 537 { 538 /* Both TSO and single send will work if count is less than 8 */ 539 if (likely(count < I40E_MAX_BUFFER_TXD)) 540 return false; 541 542 if (skb_is_gso(skb)) 543 return __i40e_chk_linearize(skb); 544 545 /* we can support up to 8 data buffers for a single send */ 546 return count != I40E_MAX_BUFFER_TXD; 547 } 548 549 /** 550 * txring_txq - Find the netdev Tx ring based on the i40e Tx ring 551 * @ring: Tx ring to find the netdev equivalent of 552 **/ 553 static inline struct netdev_queue *txring_txq(const struct i40e_ring *ring) 554 { 555 return netdev_get_tx_queue(ring->netdev, ring->queue_index); 556 } 557 #endif /* _I40E_TXRX_H_ */ 558