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 <linux/net/intel/libie/pctype.h>
8 #include <net/xdp.h>
9 #include "i40e_type.h"
10
11 /* Interrupt Throttling and Rate Limiting Goodies */
12 #define I40E_DEFAULT_IRQ_WORK 256
13
14 /* The datasheet for the X710 and XL710 indicate that the maximum value for
15 * the ITR is 8160usec which is then called out as 0xFF0 with a 2usec
16 * resolution. 8160 is 0x1FE0 when written out in hex. So instead of storing
17 * the register value which is divided by 2 lets use the actual values and
18 * avoid an excessive amount of translation.
19 */
20 #define I40E_ITR_DYNAMIC 0x8000 /* use top bit as a flag */
21 #define I40E_ITR_MASK 0x1FFE /* mask for ITR register value */
22 #define I40E_MIN_ITR 2 /* reg uses 2 usec resolution */
23 #define I40E_ITR_20K 50
24 #define I40E_ITR_8K 122
25 #define I40E_MAX_ITR 8160 /* maximum value as per datasheet */
26 #define ITR_TO_REG(setting) ((setting) & ~I40E_ITR_DYNAMIC)
27 #define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~I40E_ITR_MASK)
28 #define ITR_IS_DYNAMIC(setting) (!!((setting) & I40E_ITR_DYNAMIC))
29
30 #define I40E_ITR_RX_DEF (I40E_ITR_20K | I40E_ITR_DYNAMIC)
31 #define I40E_ITR_TX_DEF (I40E_ITR_20K | I40E_ITR_DYNAMIC)
32
33 /* 0x40 is the enable bit for interrupt rate limiting, and must be set if
34 * the value of the rate limit is non-zero
35 */
36 #define INTRL_ENA BIT(6)
37 #define I40E_MAX_INTRL 0x3B /* reg uses 4 usec resolution */
38 #define INTRL_REG_TO_USEC(intrl) ((intrl & ~INTRL_ENA) << 2)
39
40 /**
41 * i40e_intrl_usec_to_reg - convert interrupt rate limit to register
42 * @intrl: interrupt rate limit to convert
43 *
44 * This function converts a decimal interrupt rate limit to the appropriate
45 * register format expected by the firmware when setting interrupt rate limit.
46 */
i40e_intrl_usec_to_reg(int intrl)47 static inline u16 i40e_intrl_usec_to_reg(int intrl)
48 {
49 if (intrl >> 2)
50 return ((intrl >> 2) | INTRL_ENA);
51 else
52 return 0;
53 }
54
55 #define I40E_QUEUE_END_OF_LIST 0x7FF
56
57 /* this enum matches hardware bits and is meant to be used by DYN_CTLN
58 * registers and QINT registers or more generally anywhere in the manual
59 * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any
60 * register but instead is a special value meaning "don't update" ITR0/1/2.
61 */
62 enum i40e_dyn_idx {
63 I40E_IDX_ITR0 = 0,
64 I40E_IDX_ITR1 = 1,
65 I40E_IDX_ITR2 = 2,
66 I40E_ITR_NONE = 3 /* ITR_NONE must not be used as an index */
67 };
68
69 /* these are indexes into ITRN registers */
70 #define I40E_RX_ITR I40E_IDX_ITR0
71 #define I40E_TX_ITR I40E_IDX_ITR1
72 #define I40E_SW_ITR I40E_IDX_ITR2
73
74 /* Supported RSS offloads */
75 #define I40E_DEFAULT_RSS_HASHCFG ( \
76 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV4_UDP) | \
77 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV4_SCTP) | \
78 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV4_TCP) | \
79 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV4_OTHER) | \
80 BIT_ULL(LIBIE_FILTER_PCTYPE_FRAG_IPV4) | \
81 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV6_UDP) | \
82 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV6_TCP) | \
83 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV6_SCTP) | \
84 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV6_OTHER) | \
85 BIT_ULL(LIBIE_FILTER_PCTYPE_FRAG_IPV6) | \
86 BIT_ULL(LIBIE_FILTER_PCTYPE_L2_PAYLOAD))
87
88 #define I40E_DEFAULT_RSS_HASHCFG_EXPANDED (I40E_DEFAULT_RSS_HASHCFG | \
89 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \
90 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \
91 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \
92 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \
93 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \
94 BIT_ULL(LIBIE_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP))
95
96 #define i40e_pf_get_default_rss_hashcfg(pf) \
97 (test_bit(I40E_HW_CAP_MULTI_TCP_UDP_RSS_PCTYPE, (pf)->hw.caps) ? \
98 I40E_DEFAULT_RSS_HASHCFG_EXPANDED : I40E_DEFAULT_RSS_HASHCFG)
99
100 /* Supported Rx Buffer Sizes (a multiple of 128) */
101 #define I40E_RXBUFFER_256 256
102 #define I40E_RXBUFFER_1536 1536 /* 128B aligned standard Ethernet frame */
103 #define I40E_RXBUFFER_2048 2048
104 #define I40E_RXBUFFER_3072 3072 /* Used for large frames w/ padding */
105 #define I40E_MAX_RXBUFFER 9728 /* largest size for single descriptor */
106
107 /* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we
108 * reserve 2 more, and skb_shared_info adds an additional 384 bytes more,
109 * this adds up to 512 bytes of extra data meaning the smallest allocation
110 * we could have is 1K.
111 * i.e. RXBUFFER_256 --> 960 byte skb (size-1024 slab)
112 * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab)
113 */
114 #define I40E_RX_HDR_SIZE I40E_RXBUFFER_256
115 #define I40E_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))
116 #define i40e_rx_desc i40e_16byte_rx_desc
117
118 #define I40E_RX_DMA_ATTR \
119 (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING)
120
121 /* Attempt to maximize the headroom available for incoming frames. We
122 * use a 2K buffer for receives and need 1536/1534 to store the data for
123 * the frame. This leaves us with 512 bytes of room. From that we need
124 * to deduct the space needed for the shared info and the padding needed
125 * to IP align the frame.
126 *
127 * Note: For cache line sizes 256 or larger this value is going to end
128 * up negative. In these cases we should fall back to the legacy
129 * receive path.
130 */
131 #if (PAGE_SIZE < 8192)
132 #define I40E_2K_TOO_SMALL_WITH_PADDING \
133 ((NET_SKB_PAD + I40E_RXBUFFER_1536) > SKB_WITH_OVERHEAD(I40E_RXBUFFER_2048))
134
i40e_compute_pad(int rx_buf_len)135 static inline int i40e_compute_pad(int rx_buf_len)
136 {
137 int page_size, pad_size;
138
139 page_size = ALIGN(rx_buf_len, PAGE_SIZE / 2);
140 pad_size = SKB_WITH_OVERHEAD(page_size) - rx_buf_len;
141
142 return pad_size;
143 }
144
i40e_skb_pad(void)145 static inline int i40e_skb_pad(void)
146 {
147 int rx_buf_len;
148
149 /* If a 2K buffer cannot handle a standard Ethernet frame then
150 * optimize padding for a 3K buffer instead of a 1.5K buffer.
151 *
152 * For a 3K buffer we need to add enough padding to allow for
153 * tailroom due to NET_IP_ALIGN possibly shifting us out of
154 * cache-line alignment.
155 */
156 if (I40E_2K_TOO_SMALL_WITH_PADDING)
157 rx_buf_len = I40E_RXBUFFER_3072 + SKB_DATA_ALIGN(NET_IP_ALIGN);
158 else
159 rx_buf_len = I40E_RXBUFFER_1536;
160
161 /* if needed make room for NET_IP_ALIGN */
162 rx_buf_len -= NET_IP_ALIGN;
163
164 return i40e_compute_pad(rx_buf_len);
165 }
166
167 #define I40E_SKB_PAD i40e_skb_pad()
168 #else
169 #define I40E_2K_TOO_SMALL_WITH_PADDING false
170 #define I40E_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)
171 #endif
172
173 /**
174 * i40e_test_staterr - tests bits in Rx descriptor status and error fields
175 * @rx_desc: pointer to receive descriptor (in le64 format)
176 * @stat_err_bits: value to mask
177 *
178 * This function does some fast chicanery in order to return the
179 * value of the mask which is really only used for boolean tests.
180 * The status_error_len doesn't need to be shifted because it begins
181 * at offset zero.
182 */
i40e_test_staterr(union i40e_rx_desc * rx_desc,const u64 stat_err_bits)183 static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc,
184 const u64 stat_err_bits)
185 {
186 return !!(rx_desc->wb.qword1.status_error_len &
187 cpu_to_le64(stat_err_bits));
188 }
189
190 /* How many Rx Buffers do we bundle into one write to the hardware ? */
191 #define I40E_RX_BUFFER_WRITE 32 /* Must be power of 2 */
192
193 #define I40E_RX_NEXT_DESC(r, i, n) \
194 do { \
195 (i)++; \
196 if ((i) == (r)->count) \
197 i = 0; \
198 (n) = I40E_RX_DESC((r), (i)); \
199 } while (0)
200
201
202 #define I40E_MAX_BUFFER_TXD 8
203 #define I40E_MIN_TX_LEN 17
204
205 /* The size limit for a transmit buffer in a descriptor is (16K - 1).
206 * In order to align with the read requests we will align the value to
207 * the nearest 4K which represents our maximum read request size.
208 */
209 #define I40E_MAX_READ_REQ_SIZE 4096
210 #define I40E_MAX_DATA_PER_TXD (16 * 1024 - 1)
211 #define I40E_MAX_DATA_PER_TXD_ALIGNED \
212 (I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1))
213
214 /**
215 * i40e_txd_use_count - estimate the number of descriptors needed for Tx
216 * @size: transmit request size in bytes
217 *
218 * Due to hardware alignment restrictions (4K alignment), we need to
219 * assume that we can have no more than 12K of data per descriptor, even
220 * though each descriptor can take up to 16K - 1 bytes of aligned memory.
221 * Thus, we need to divide by 12K. But division is slow! Instead,
222 * we decompose the operation into shifts and one relatively cheap
223 * multiply operation.
224 *
225 * To divide by 12K, we first divide by 4K, then divide by 3:
226 * To divide by 4K, shift right by 12 bits
227 * To divide by 3, multiply by 85, then divide by 256
228 * (Divide by 256 is done by shifting right by 8 bits)
229 * Finally, we add one to round up. Because 256 isn't an exact multiple of
230 * 3, we'll underestimate near each multiple of 12K. This is actually more
231 * accurate as we have 4K - 1 of wiggle room that we can fit into the last
232 * segment. For our purposes this is accurate out to 1M which is orders of
233 * magnitude greater than our largest possible GSO size.
234 *
235 * This would then be implemented as:
236 * return (((size >> 12) * 85) >> 8) + 1;
237 *
238 * Since multiplication and division are commutative, we can reorder
239 * operations into:
240 * return ((size * 85) >> 20) + 1;
241 */
i40e_txd_use_count(unsigned int size)242 static inline unsigned int i40e_txd_use_count(unsigned int size)
243 {
244 return ((size * 85) >> 20) + 1;
245 }
246
247 /* Tx Descriptors needed, worst case */
248 #define DESC_NEEDED (MAX_SKB_FRAGS + 6)
249
250 #define I40E_TX_FLAGS_HW_VLAN BIT(1)
251 #define I40E_TX_FLAGS_SW_VLAN BIT(2)
252 #define I40E_TX_FLAGS_TSO BIT(3)
253 #define I40E_TX_FLAGS_IPV4 BIT(4)
254 #define I40E_TX_FLAGS_IPV6 BIT(5)
255 #define I40E_TX_FLAGS_TSYN BIT(8)
256 #define I40E_TX_FLAGS_FD_SB BIT(9)
257 #define I40E_TX_FLAGS_UDP_TUNNEL BIT(10)
258 #define I40E_TX_FLAGS_VLAN_MASK 0xffff0000
259 #define I40E_TX_FLAGS_VLAN_PRIO_MASK 0xe0000000
260 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT 29
261 #define I40E_TX_FLAGS_VLAN_SHIFT 16
262
263 struct i40e_tx_buffer {
264 struct i40e_tx_desc *next_to_watch;
265 union {
266 struct xdp_frame *xdpf;
267 struct sk_buff *skb;
268 void *raw_buf;
269 };
270 unsigned int bytecount;
271 unsigned short gso_segs;
272
273 DEFINE_DMA_UNMAP_ADDR(dma);
274 DEFINE_DMA_UNMAP_LEN(len);
275 u32 tx_flags;
276 };
277
278 struct i40e_rx_buffer {
279 dma_addr_t dma;
280 struct page *page;
281 __u32 page_offset;
282 __u16 pagecnt_bias;
283 __u32 page_count;
284 };
285
286 struct i40e_queue_stats {
287 u64 packets;
288 u64 bytes;
289 };
290
291 struct i40e_tx_queue_stats {
292 u64 restart_queue;
293 u64 tx_busy;
294 u64 tx_done_old;
295 u64 tx_linearize;
296 u64 tx_force_wb;
297 u64 tx_stopped;
298 int prev_pkt_ctr;
299 };
300
301 struct i40e_rx_queue_stats {
302 u64 non_eop_descs;
303 u64 alloc_page_failed;
304 u64 alloc_buff_failed;
305 u64 page_reuse_count;
306 u64 page_alloc_count;
307 u64 page_waive_count;
308 u64 page_busy_count;
309 };
310
311 enum i40e_ring_state {
312 __I40E_TX_FDIR_INIT_DONE,
313 __I40E_TX_XPS_INIT_DONE,
314 __I40E_RING_STATE_NBITS /* must be last */
315 };
316
317 /* some useful defines for virtchannel interface, which
318 * is the only remaining user of header split
319 */
320 #define I40E_RX_DTYPE_HEADER_SPLIT 1
321 #define I40E_RX_SPLIT_L2 0x1
322 #define I40E_RX_SPLIT_IP 0x2
323 #define I40E_RX_SPLIT_TCP_UDP 0x4
324 #define I40E_RX_SPLIT_SCTP 0x8
325
326 /* struct that defines a descriptor ring, associated with a VSI */
327 struct i40e_ring {
328 struct i40e_ring *next; /* pointer to next ring in q_vector */
329 void *desc; /* Descriptor ring memory */
330 struct device *dev; /* Used for DMA mapping */
331 struct net_device *netdev; /* netdev ring maps to */
332 struct bpf_prog *xdp_prog;
333 union {
334 struct i40e_tx_buffer *tx_bi;
335 struct i40e_rx_buffer *rx_bi;
336 struct xdp_buff **rx_bi_zc;
337 };
338 DECLARE_BITMAP(state, __I40E_RING_STATE_NBITS);
339 u16 queue_index; /* Queue number of ring */
340 u8 dcb_tc; /* Traffic class of ring */
341 u8 __iomem *tail;
342
343 /* Storing xdp_buff on ring helps in saving the state of partially built
344 * packet when i40e_clean_rx_ring_irq() must return before it sees EOP
345 * and to resume packet building for this ring in the next call to
346 * i40e_clean_rx_ring_irq().
347 */
348 struct xdp_buff xdp;
349
350 /* Next descriptor to be processed; next_to_clean is updated only on
351 * processing EOP descriptor
352 */
353 u16 next_to_process;
354 /* high bit set means dynamic, use accessor routines to read/write.
355 * hardware only supports 2us resolution for the ITR registers.
356 * these values always store the USER setting, and must be converted
357 * before programming to a register.
358 */
359 u16 itr_setting;
360
361 u16 count; /* Number of descriptors */
362 u16 reg_idx; /* HW register index of the ring */
363 u16 rx_buf_len;
364
365 /* used in interrupt processing */
366 u16 next_to_use;
367 u16 next_to_clean;
368 u16 xdp_tx_active;
369
370 u8 atr_sample_rate;
371 u8 atr_count;
372
373 bool ring_active; /* is ring online or not */
374 bool arm_wb; /* do something to arm write back */
375 u8 packet_stride;
376
377 u16 flags;
378 #define I40E_TXR_FLAGS_WB_ON_ITR BIT(0)
379 #define I40E_RXR_FLAGS_BUILD_SKB_ENABLED BIT(1)
380 #define I40E_TXR_FLAGS_XDP BIT(2)
381
382 /* stats structs */
383 struct i40e_queue_stats stats;
384 struct u64_stats_sync syncp;
385 union {
386 struct i40e_tx_queue_stats tx_stats;
387 struct i40e_rx_queue_stats rx_stats;
388 };
389
390 unsigned int size; /* length of descriptor ring in bytes */
391 dma_addr_t dma; /* physical address of ring */
392
393 struct i40e_vsi *vsi; /* Backreference to associated VSI */
394 struct i40e_q_vector *q_vector; /* Backreference to associated vector */
395
396 struct rcu_head rcu; /* to avoid race on free */
397 u16 next_to_alloc;
398
399 struct i40e_channel *ch;
400 u16 rx_offset;
401 struct xdp_rxq_info xdp_rxq;
402 struct xsk_buff_pool *xsk_pool;
403 } ____cacheline_internodealigned_in_smp;
404
ring_uses_build_skb(struct i40e_ring * ring)405 static inline bool ring_uses_build_skb(struct i40e_ring *ring)
406 {
407 return !!(ring->flags & I40E_RXR_FLAGS_BUILD_SKB_ENABLED);
408 }
409
set_ring_build_skb_enabled(struct i40e_ring * ring)410 static inline void set_ring_build_skb_enabled(struct i40e_ring *ring)
411 {
412 ring->flags |= I40E_RXR_FLAGS_BUILD_SKB_ENABLED;
413 }
414
clear_ring_build_skb_enabled(struct i40e_ring * ring)415 static inline void clear_ring_build_skb_enabled(struct i40e_ring *ring)
416 {
417 ring->flags &= ~I40E_RXR_FLAGS_BUILD_SKB_ENABLED;
418 }
419
ring_is_xdp(struct i40e_ring * ring)420 static inline bool ring_is_xdp(struct i40e_ring *ring)
421 {
422 return !!(ring->flags & I40E_TXR_FLAGS_XDP);
423 }
424
set_ring_xdp(struct i40e_ring * ring)425 static inline void set_ring_xdp(struct i40e_ring *ring)
426 {
427 ring->flags |= I40E_TXR_FLAGS_XDP;
428 }
429
430 #define I40E_ITR_ADAPTIVE_MIN_INC 0x0002
431 #define I40E_ITR_ADAPTIVE_MIN_USECS 0x0002
432 #define I40E_ITR_ADAPTIVE_MAX_USECS 0x007e
433 #define I40E_ITR_ADAPTIVE_LATENCY 0x8000
434 #define I40E_ITR_ADAPTIVE_BULK 0x0000
435
436 struct i40e_ring_container {
437 struct i40e_ring *ring; /* pointer to linked list of ring(s) */
438 unsigned long next_update; /* jiffies value of next update */
439 unsigned int total_bytes; /* total bytes processed this int */
440 unsigned int total_packets; /* total packets processed this int */
441 u16 count;
442 u16 target_itr; /* target ITR setting for ring(s) */
443 u16 current_itr; /* current ITR setting for ring(s) */
444 };
445
446 /* iterator for handling rings in ring container */
447 #define i40e_for_each_ring(pos, head) \
448 for (pos = (head).ring; pos != NULL; pos = pos->next)
449
i40e_rx_pg_order(struct i40e_ring * ring)450 static inline unsigned int i40e_rx_pg_order(struct i40e_ring *ring)
451 {
452 #if (PAGE_SIZE < 8192)
453 if (ring->rx_buf_len > (PAGE_SIZE / 2))
454 return 1;
455 #endif
456 return 0;
457 }
458
459 #define i40e_rx_pg_size(_ring) (PAGE_SIZE << i40e_rx_pg_order(_ring))
460
461 bool i40e_alloc_rx_buffers(struct i40e_ring *rxr, u16 cleaned_count);
462 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
463 u16 i40e_lan_select_queue(struct net_device *netdev, struct sk_buff *skb,
464 struct net_device *sb_dev);
465 void i40e_clean_tx_ring(struct i40e_ring *tx_ring);
466 void i40e_clean_rx_ring(struct i40e_ring *rx_ring);
467 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring);
468 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring);
469 void i40e_free_tx_resources(struct i40e_ring *tx_ring);
470 void i40e_free_rx_resources(struct i40e_ring *rx_ring);
471 int i40e_napi_poll(struct napi_struct *napi, int budget);
472 void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector);
473 u32 i40e_get_tx_pending(struct i40e_ring *ring, bool in_sw);
474 void i40e_detect_recover_hung(struct i40e_pf *pf);
475 int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size);
476 bool __i40e_chk_linearize(struct sk_buff *skb);
477 int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
478 u32 flags);
479 bool i40e_is_non_eop(struct i40e_ring *rx_ring,
480 union i40e_rx_desc *rx_desc);
481
482 /**
483 * i40e_get_head - Retrieve head from head writeback
484 * @tx_ring: tx ring to fetch head of
485 *
486 * Returns value of Tx ring head based on value stored
487 * in head write-back location
488 **/
i40e_get_head(struct i40e_ring * tx_ring)489 static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
490 {
491 void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
492
493 return le32_to_cpu(*(volatile __le32 *)head);
494 }
495
496 /**
497 * i40e_xmit_descriptor_count - calculate number of Tx descriptors needed
498 * @skb: send buffer
499 *
500 * Returns number of data descriptors needed for this skb. Returns 0 to indicate
501 * there is not enough descriptors available in this ring since we need at least
502 * one descriptor.
503 **/
i40e_xmit_descriptor_count(struct sk_buff * skb)504 static inline int i40e_xmit_descriptor_count(struct sk_buff *skb)
505 {
506 const skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
507 unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
508 int count = 0, size = skb_headlen(skb);
509
510 for (;;) {
511 count += i40e_txd_use_count(size);
512
513 if (!nr_frags--)
514 break;
515
516 size = skb_frag_size(frag++);
517 }
518
519 return count;
520 }
521
522 /**
523 * i40e_maybe_stop_tx - 1st level check for Tx stop conditions
524 * @tx_ring: the ring to be checked
525 * @size: the size buffer we want to assure is available
526 *
527 * Returns 0 if stop is not needed
528 **/
i40e_maybe_stop_tx(struct i40e_ring * tx_ring,int size)529 static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
530 {
531 if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
532 return 0;
533 return __i40e_maybe_stop_tx(tx_ring, size);
534 }
535
536 /**
537 * i40e_chk_linearize - Check if there are more than 8 fragments per packet
538 * @skb: send buffer
539 * @count: number of buffers used
540 *
541 * Note: Our HW can't scatter-gather more than 8 fragments to build
542 * a packet on the wire and so we need to figure out the cases where we
543 * need to linearize the skb.
544 **/
i40e_chk_linearize(struct sk_buff * skb,int count)545 static inline bool i40e_chk_linearize(struct sk_buff *skb, int count)
546 {
547 /* Both TSO and single send will work if count is less than 8 */
548 if (likely(count < I40E_MAX_BUFFER_TXD))
549 return false;
550
551 if (skb_is_gso(skb))
552 return __i40e_chk_linearize(skb);
553
554 /* we can support up to 8 data buffers for a single send */
555 return count != I40E_MAX_BUFFER_TXD;
556 }
557
558 /**
559 * txring_txq - Find the netdev Tx ring based on the i40e Tx ring
560 * @ring: Tx ring to find the netdev equivalent of
561 **/
txring_txq(const struct i40e_ring * ring)562 static inline struct netdev_queue *txring_txq(const struct i40e_ring *ring)
563 {
564 return netdev_get_tx_queue(ring->netdev, ring->queue_index);
565 }
566 #endif /* _I40E_TXRX_H_ */
567