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 #include "i40e_type.h" 9 10 /* Interrupt Throttling and Rate Limiting Goodies */ 11 #define I40E_DEFAULT_IRQ_WORK 256 12 13 /* The datasheet for the X710 and XL710 indicate that the maximum value for 14 * the ITR is 8160usec which is then called out as 0xFF0 with a 2usec 15 * resolution. 8160 is 0x1FE0 when written out in hex. So instead of storing 16 * the register value which is divided by 2 lets use the actual values and 17 * avoid an excessive amount of translation. 18 */ 19 #define I40E_ITR_DYNAMIC 0x8000 /* use top bit as a flag */ 20 #define I40E_ITR_MASK 0x1FFE /* mask for ITR register value */ 21 #define I40E_MIN_ITR 2 /* reg uses 2 usec resolution */ 22 #define I40E_ITR_20K 50 23 #define I40E_ITR_8K 122 24 #define I40E_MAX_ITR 8160 /* maximum value as per datasheet */ 25 #define ITR_TO_REG(setting) ((setting) & ~I40E_ITR_DYNAMIC) 26 #define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~I40E_ITR_MASK) 27 #define ITR_IS_DYNAMIC(setting) (!!((setting) & I40E_ITR_DYNAMIC)) 28 29 #define I40E_ITR_RX_DEF (I40E_ITR_20K | I40E_ITR_DYNAMIC) 30 #define I40E_ITR_TX_DEF (I40E_ITR_20K | I40E_ITR_DYNAMIC) 31 32 /* 0x40 is the enable bit for interrupt rate limiting, and must be set if 33 * the value of the rate limit is non-zero 34 */ 35 #define INTRL_ENA BIT(6) 36 #define I40E_MAX_INTRL 0x3B /* reg uses 4 usec resolution */ 37 #define INTRL_REG_TO_USEC(intrl) ((intrl & ~INTRL_ENA) << 2) 38 39 /** 40 * i40e_intrl_usec_to_reg - convert interrupt rate limit to register 41 * @intrl: interrupt rate limit to convert 42 * 43 * This function converts a decimal interrupt rate limit to the appropriate 44 * register format expected by the firmware when setting interrupt rate limit. 45 */ 46 static inline u16 i40e_intrl_usec_to_reg(int intrl) 47 { 48 if (intrl >> 2) 49 return ((intrl >> 2) | INTRL_ENA); 50 else 51 return 0; 52 } 53 54 #define I40E_QUEUE_END_OF_LIST 0x7FF 55 56 /* this enum matches hardware bits and is meant to be used by DYN_CTLN 57 * registers and QINT registers or more generally anywhere in the manual 58 * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any 59 * register but instead is a special value meaning "don't update" ITR0/1/2. 60 */ 61 enum i40e_dyn_idx { 62 I40E_IDX_ITR0 = 0, 63 I40E_IDX_ITR1 = 1, 64 I40E_IDX_ITR2 = 2, 65 I40E_ITR_NONE = 3 /* ITR_NONE must not be used as an index */ 66 }; 67 68 /* these are indexes into ITRN registers */ 69 #define I40E_RX_ITR I40E_IDX_ITR0 70 #define I40E_TX_ITR I40E_IDX_ITR1 71 #define I40E_SW_ITR I40E_IDX_ITR2 72 73 /* Supported RSS offloads */ 74 #define I40E_DEFAULT_RSS_HENA ( \ 75 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_UDP) | \ 76 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_SCTP) | \ 77 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP) | \ 78 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_OTHER) | \ 79 BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV4) | \ 80 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_UDP) | \ 81 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP) | \ 82 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_SCTP) | \ 83 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_OTHER) | \ 84 BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV6) | \ 85 BIT_ULL(I40E_FILTER_PCTYPE_L2_PAYLOAD)) 86 87 #define I40E_DEFAULT_RSS_HENA_EXPANDED (I40E_DEFAULT_RSS_HENA | \ 88 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \ 89 BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \ 90 BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \ 91 BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \ 92 BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \ 93 BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP)) 94 95 #define i40e_pf_get_default_rss_hena(pf) \ 96 (test_bit(I40E_HW_CAP_MULTI_TCP_UDP_RSS_PCTYPE, (pf)->hw.caps) ? \ 97 I40E_DEFAULT_RSS_HENA_EXPANDED : I40E_DEFAULT_RSS_HENA) 98 99 /* Supported Rx Buffer Sizes (a multiple of 128) */ 100 #define I40E_RXBUFFER_256 256 101 #define I40E_RXBUFFER_1536 1536 /* 128B aligned standard Ethernet frame */ 102 #define I40E_RXBUFFER_2048 2048 103 #define I40E_RXBUFFER_3072 3072 /* Used for large frames w/ padding */ 104 #define I40E_MAX_RXBUFFER 9728 /* largest size for single descriptor */ 105 106 /* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we 107 * reserve 2 more, and skb_shared_info adds an additional 384 bytes more, 108 * this adds up to 512 bytes of extra data meaning the smallest allocation 109 * we could have is 1K. 110 * i.e. RXBUFFER_256 --> 960 byte skb (size-1024 slab) 111 * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab) 112 */ 113 #define I40E_RX_HDR_SIZE I40E_RXBUFFER_256 114 #define I40E_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2)) 115 #define i40e_rx_desc i40e_16byte_rx_desc 116 117 #define I40E_RX_DMA_ATTR \ 118 (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING) 119 120 /* Attempt to maximize the headroom available for incoming frames. We 121 * use a 2K buffer for receives and need 1536/1534 to store the data for 122 * the frame. This leaves us with 512 bytes of room. From that we need 123 * to deduct the space needed for the shared info and the padding needed 124 * to IP align the frame. 125 * 126 * Note: For cache line sizes 256 or larger this value is going to end 127 * up negative. In these cases we should fall back to the legacy 128 * receive path. 129 */ 130 #if (PAGE_SIZE < 8192) 131 #define I40E_2K_TOO_SMALL_WITH_PADDING \ 132 ((NET_SKB_PAD + I40E_RXBUFFER_1536) > SKB_WITH_OVERHEAD(I40E_RXBUFFER_2048)) 133 134 static inline int i40e_compute_pad(int rx_buf_len) 135 { 136 int page_size, pad_size; 137 138 page_size = ALIGN(rx_buf_len, PAGE_SIZE / 2); 139 pad_size = SKB_WITH_OVERHEAD(page_size) - rx_buf_len; 140 141 return pad_size; 142 } 143 144 static inline int i40e_skb_pad(void) 145 { 146 int rx_buf_len; 147 148 /* If a 2K buffer cannot handle a standard Ethernet frame then 149 * optimize padding for a 3K buffer instead of a 1.5K buffer. 150 * 151 * For a 3K buffer we need to add enough padding to allow for 152 * tailroom due to NET_IP_ALIGN possibly shifting us out of 153 * cache-line alignment. 154 */ 155 if (I40E_2K_TOO_SMALL_WITH_PADDING) 156 rx_buf_len = I40E_RXBUFFER_3072 + SKB_DATA_ALIGN(NET_IP_ALIGN); 157 else 158 rx_buf_len = I40E_RXBUFFER_1536; 159 160 /* if needed make room for NET_IP_ALIGN */ 161 rx_buf_len -= NET_IP_ALIGN; 162 163 return i40e_compute_pad(rx_buf_len); 164 } 165 166 #define I40E_SKB_PAD i40e_skb_pad() 167 #else 168 #define I40E_2K_TOO_SMALL_WITH_PADDING false 169 #define I40E_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN) 170 #endif 171 172 /** 173 * i40e_test_staterr - tests bits in Rx descriptor status and error fields 174 * @rx_desc: pointer to receive descriptor (in le64 format) 175 * @stat_err_bits: value to mask 176 * 177 * This function does some fast chicanery in order to return the 178 * value of the mask which is really only used for boolean tests. 179 * The status_error_len doesn't need to be shifted because it begins 180 * at offset zero. 181 */ 182 static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc, 183 const u64 stat_err_bits) 184 { 185 return !!(rx_desc->wb.qword1.status_error_len & 186 cpu_to_le64(stat_err_bits)); 187 } 188 189 /* How many Rx Buffers do we bundle into one write to the hardware ? */ 190 #define I40E_RX_BUFFER_WRITE 32 /* Must be power of 2 */ 191 192 #define I40E_RX_NEXT_DESC(r, i, n) \ 193 do { \ 194 (i)++; \ 195 if ((i) == (r)->count) \ 196 i = 0; \ 197 (n) = I40E_RX_DESC((r), (i)); \ 198 } while (0) 199 200 201 #define I40E_MAX_BUFFER_TXD 8 202 #define I40E_MIN_TX_LEN 17 203 204 /* The size limit for a transmit buffer in a descriptor is (16K - 1). 205 * In order to align with the read requests we will align the value to 206 * the nearest 4K which represents our maximum read request size. 207 */ 208 #define I40E_MAX_READ_REQ_SIZE 4096 209 #define I40E_MAX_DATA_PER_TXD (16 * 1024 - 1) 210 #define I40E_MAX_DATA_PER_TXD_ALIGNED \ 211 (I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1)) 212 213 /** 214 * i40e_txd_use_count - estimate the number of descriptors needed for Tx 215 * @size: transmit request size in bytes 216 * 217 * Due to hardware alignment restrictions (4K alignment), we need to 218 * assume that we can have no more than 12K of data per descriptor, even 219 * though each descriptor can take up to 16K - 1 bytes of aligned memory. 220 * Thus, we need to divide by 12K. But division is slow! Instead, 221 * we decompose the operation into shifts and one relatively cheap 222 * multiply operation. 223 * 224 * To divide by 12K, we first divide by 4K, then divide by 3: 225 * To divide by 4K, shift right by 12 bits 226 * To divide by 3, multiply by 85, then divide by 256 227 * (Divide by 256 is done by shifting right by 8 bits) 228 * Finally, we add one to round up. Because 256 isn't an exact multiple of 229 * 3, we'll underestimate near each multiple of 12K. This is actually more 230 * accurate as we have 4K - 1 of wiggle room that we can fit into the last 231 * segment. For our purposes this is accurate out to 1M which is orders of 232 * magnitude greater than our largest possible GSO size. 233 * 234 * This would then be implemented as: 235 * return (((size >> 12) * 85) >> 8) + 1; 236 * 237 * Since multiplication and division are commutative, we can reorder 238 * operations into: 239 * return ((size * 85) >> 20) + 1; 240 */ 241 static inline unsigned int i40e_txd_use_count(unsigned int size) 242 { 243 return ((size * 85) >> 20) + 1; 244 } 245 246 /* Tx Descriptors needed, worst case */ 247 #define DESC_NEEDED (MAX_SKB_FRAGS + 6) 248 249 #define I40E_TX_FLAGS_HW_VLAN BIT(1) 250 #define I40E_TX_FLAGS_SW_VLAN BIT(2) 251 #define I40E_TX_FLAGS_TSO BIT(3) 252 #define I40E_TX_FLAGS_IPV4 BIT(4) 253 #define I40E_TX_FLAGS_IPV6 BIT(5) 254 #define I40E_TX_FLAGS_TSYN BIT(8) 255 #define I40E_TX_FLAGS_FD_SB BIT(9) 256 #define I40E_TX_FLAGS_UDP_TUNNEL BIT(10) 257 #define I40E_TX_FLAGS_VLAN_MASK 0xffff0000 258 #define I40E_TX_FLAGS_VLAN_PRIO_MASK 0xe0000000 259 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT 29 260 #define I40E_TX_FLAGS_VLAN_SHIFT 16 261 262 struct i40e_tx_buffer { 263 struct i40e_tx_desc *next_to_watch; 264 union { 265 struct xdp_frame *xdpf; 266 struct sk_buff *skb; 267 void *raw_buf; 268 }; 269 unsigned int bytecount; 270 unsigned short gso_segs; 271 272 DEFINE_DMA_UNMAP_ADDR(dma); 273 DEFINE_DMA_UNMAP_LEN(len); 274 u32 tx_flags; 275 }; 276 277 struct i40e_rx_buffer { 278 dma_addr_t dma; 279 struct page *page; 280 __u32 page_offset; 281 __u16 pagecnt_bias; 282 __u32 page_count; 283 }; 284 285 struct i40e_queue_stats { 286 u64 packets; 287 u64 bytes; 288 }; 289 290 struct i40e_tx_queue_stats { 291 u64 restart_queue; 292 u64 tx_busy; 293 u64 tx_done_old; 294 u64 tx_linearize; 295 u64 tx_force_wb; 296 u64 tx_stopped; 297 int prev_pkt_ctr; 298 }; 299 300 struct i40e_rx_queue_stats { 301 u64 non_eop_descs; 302 u64 alloc_page_failed; 303 u64 alloc_buff_failed; 304 u64 page_reuse_count; 305 u64 page_alloc_count; 306 u64 page_waive_count; 307 u64 page_busy_count; 308 }; 309 310 enum i40e_ring_state { 311 __I40E_TX_FDIR_INIT_DONE, 312 __I40E_TX_XPS_INIT_DONE, 313 __I40E_RING_STATE_NBITS /* must be last */ 314 }; 315 316 /* some useful defines for virtchannel interface, which 317 * is the only remaining user of header split 318 */ 319 #define I40E_RX_DTYPE_HEADER_SPLIT 1 320 #define I40E_RX_SPLIT_L2 0x1 321 #define I40E_RX_SPLIT_IP 0x2 322 #define I40E_RX_SPLIT_TCP_UDP 0x4 323 #define I40E_RX_SPLIT_SCTP 0x8 324 325 /* struct that defines a descriptor ring, associated with a VSI */ 326 struct i40e_ring { 327 struct i40e_ring *next; /* pointer to next ring in q_vector */ 328 void *desc; /* Descriptor ring memory */ 329 struct device *dev; /* Used for DMA mapping */ 330 struct net_device *netdev; /* netdev ring maps to */ 331 struct bpf_prog *xdp_prog; 332 union { 333 struct i40e_tx_buffer *tx_bi; 334 struct i40e_rx_buffer *rx_bi; 335 struct xdp_buff **rx_bi_zc; 336 }; 337 DECLARE_BITMAP(state, __I40E_RING_STATE_NBITS); 338 u16 queue_index; /* Queue number of ring */ 339 u8 dcb_tc; /* Traffic class of ring */ 340 u8 __iomem *tail; 341 342 /* Storing xdp_buff on ring helps in saving the state of partially built 343 * packet when i40e_clean_rx_ring_irq() must return before it sees EOP 344 * and to resume packet building for this ring in the next call to 345 * i40e_clean_rx_ring_irq(). 346 */ 347 struct xdp_buff xdp; 348 349 /* Next descriptor to be processed; next_to_clean is updated only on 350 * processing EOP descriptor 351 */ 352 u16 next_to_process; 353 /* high bit set means dynamic, use accessor routines to read/write. 354 * hardware only supports 2us resolution for the ITR registers. 355 * these values always store the USER setting, and must be converted 356 * before programming to a register. 357 */ 358 u16 itr_setting; 359 360 u16 count; /* Number of descriptors */ 361 u16 reg_idx; /* HW register index of the ring */ 362 u16 rx_buf_len; 363 364 /* used in interrupt processing */ 365 u16 next_to_use; 366 u16 next_to_clean; 367 u16 xdp_tx_active; 368 369 u8 atr_sample_rate; 370 u8 atr_count; 371 372 bool ring_active; /* is ring online or not */ 373 bool arm_wb; /* do something to arm write back */ 374 u8 packet_stride; 375 376 u16 flags; 377 #define I40E_TXR_FLAGS_WB_ON_ITR BIT(0) 378 #define I40E_RXR_FLAGS_BUILD_SKB_ENABLED BIT(1) 379 #define I40E_TXR_FLAGS_XDP BIT(2) 380 381 /* stats structs */ 382 struct i40e_queue_stats stats; 383 struct u64_stats_sync syncp; 384 union { 385 struct i40e_tx_queue_stats tx_stats; 386 struct i40e_rx_queue_stats rx_stats; 387 }; 388 389 unsigned int size; /* length of descriptor ring in bytes */ 390 dma_addr_t dma; /* physical address of ring */ 391 392 struct i40e_vsi *vsi; /* Backreference to associated VSI */ 393 struct i40e_q_vector *q_vector; /* Backreference to associated vector */ 394 395 struct rcu_head rcu; /* to avoid race on free */ 396 u16 next_to_alloc; 397 398 struct i40e_channel *ch; 399 u16 rx_offset; 400 struct xdp_rxq_info xdp_rxq; 401 struct xsk_buff_pool *xsk_pool; 402 } ____cacheline_internodealigned_in_smp; 403 404 static inline bool ring_uses_build_skb(struct i40e_ring *ring) 405 { 406 return !!(ring->flags & I40E_RXR_FLAGS_BUILD_SKB_ENABLED); 407 } 408 409 static inline void set_ring_build_skb_enabled(struct i40e_ring *ring) 410 { 411 ring->flags |= I40E_RXR_FLAGS_BUILD_SKB_ENABLED; 412 } 413 414 static inline void clear_ring_build_skb_enabled(struct i40e_ring *ring) 415 { 416 ring->flags &= ~I40E_RXR_FLAGS_BUILD_SKB_ENABLED; 417 } 418 419 static inline bool ring_is_xdp(struct i40e_ring *ring) 420 { 421 return !!(ring->flags & I40E_TXR_FLAGS_XDP); 422 } 423 424 static inline void set_ring_xdp(struct i40e_ring *ring) 425 { 426 ring->flags |= I40E_TXR_FLAGS_XDP; 427 } 428 429 #define I40E_ITR_ADAPTIVE_MIN_INC 0x0002 430 #define I40E_ITR_ADAPTIVE_MIN_USECS 0x0002 431 #define I40E_ITR_ADAPTIVE_MAX_USECS 0x007e 432 #define I40E_ITR_ADAPTIVE_LATENCY 0x8000 433 #define I40E_ITR_ADAPTIVE_BULK 0x0000 434 435 struct i40e_ring_container { 436 struct i40e_ring *ring; /* pointer to linked list of ring(s) */ 437 unsigned long next_update; /* jiffies value of next update */ 438 unsigned int total_bytes; /* total bytes processed this int */ 439 unsigned int total_packets; /* total packets processed this int */ 440 u16 count; 441 u16 target_itr; /* target ITR setting for ring(s) */ 442 u16 current_itr; /* current ITR setting for ring(s) */ 443 }; 444 445 /* iterator for handling rings in ring container */ 446 #define i40e_for_each_ring(pos, head) \ 447 for (pos = (head).ring; pos != NULL; pos = pos->next) 448 449 static inline unsigned int i40e_rx_pg_order(struct i40e_ring *ring) 450 { 451 #if (PAGE_SIZE < 8192) 452 if (ring->rx_buf_len > (PAGE_SIZE / 2)) 453 return 1; 454 #endif 455 return 0; 456 } 457 458 #define i40e_rx_pg_size(_ring) (PAGE_SIZE << i40e_rx_pg_order(_ring)) 459 460 bool i40e_alloc_rx_buffers(struct i40e_ring *rxr, u16 cleaned_count); 461 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev); 462 u16 i40e_lan_select_queue(struct net_device *netdev, struct sk_buff *skb, 463 struct net_device *sb_dev); 464 void i40e_clean_tx_ring(struct i40e_ring *tx_ring); 465 void i40e_clean_rx_ring(struct i40e_ring *rx_ring); 466 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring); 467 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring); 468 void i40e_free_tx_resources(struct i40e_ring *tx_ring); 469 void i40e_free_rx_resources(struct i40e_ring *rx_ring); 470 int i40e_napi_poll(struct napi_struct *napi, int budget); 471 void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector); 472 u32 i40e_get_tx_pending(struct i40e_ring *ring, bool in_sw); 473 void i40e_detect_recover_hung(struct i40e_pf *pf); 474 int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size); 475 bool __i40e_chk_linearize(struct sk_buff *skb); 476 int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, 477 u32 flags); 478 bool i40e_is_non_eop(struct i40e_ring *rx_ring, 479 union i40e_rx_desc *rx_desc); 480 481 /** 482 * i40e_get_head - Retrieve head from head writeback 483 * @tx_ring: tx ring to fetch head of 484 * 485 * Returns value of Tx ring head based on value stored 486 * in head write-back location 487 **/ 488 static inline u32 i40e_get_head(struct i40e_ring *tx_ring) 489 { 490 void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count; 491 492 return le32_to_cpu(*(volatile __le32 *)head); 493 } 494 495 /** 496 * i40e_xmit_descriptor_count - calculate number of Tx descriptors needed 497 * @skb: send buffer 498 * 499 * Returns number of data descriptors needed for this skb. Returns 0 to indicate 500 * there is not enough descriptors available in this ring since we need at least 501 * one descriptor. 502 **/ 503 static inline int i40e_xmit_descriptor_count(struct sk_buff *skb) 504 { 505 const skb_frag_t *frag = &skb_shinfo(skb)->frags[0]; 506 unsigned int nr_frags = skb_shinfo(skb)->nr_frags; 507 int count = 0, size = skb_headlen(skb); 508 509 for (;;) { 510 count += i40e_txd_use_count(size); 511 512 if (!nr_frags--) 513 break; 514 515 size = skb_frag_size(frag++); 516 } 517 518 return count; 519 } 520 521 /** 522 * i40e_maybe_stop_tx - 1st level check for Tx stop conditions 523 * @tx_ring: the ring to be checked 524 * @size: the size buffer we want to assure is available 525 * 526 * Returns 0 if stop is not needed 527 **/ 528 static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size) 529 { 530 if (likely(I40E_DESC_UNUSED(tx_ring) >= size)) 531 return 0; 532 return __i40e_maybe_stop_tx(tx_ring, size); 533 } 534 535 /** 536 * i40e_chk_linearize - Check if there are more than 8 fragments per packet 537 * @skb: send buffer 538 * @count: number of buffers used 539 * 540 * Note: Our HW can't scatter-gather more than 8 fragments to build 541 * a packet on the wire and so we need to figure out the cases where we 542 * need to linearize the skb. 543 **/ 544 static inline bool i40e_chk_linearize(struct sk_buff *skb, int count) 545 { 546 /* Both TSO and single send will work if count is less than 8 */ 547 if (likely(count < I40E_MAX_BUFFER_TXD)) 548 return false; 549 550 if (skb_is_gso(skb)) 551 return __i40e_chk_linearize(skb); 552 553 /* we can support up to 8 data buffers for a single send */ 554 return count != I40E_MAX_BUFFER_TXD; 555 } 556 557 /** 558 * txring_txq - Find the netdev Tx ring based on the i40e Tx ring 559 * @ring: Tx ring to find the netdev equivalent of 560 **/ 561 static inline struct netdev_queue *txring_txq(const struct i40e_ring *ring) 562 { 563 return netdev_get_tx_queue(ring->netdev, ring->queue_index); 564 } 565 #endif /* _I40E_TXRX_H_ */ 566