1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright(c) 2013 - 2018 Intel Corporation. */
3
4#ifndef _IAVF_TXRX_H_
5#define _IAVF_TXRX_H_
6
7/* Interrupt Throttling and Rate Limiting Goodies */
8#define IAVF_DEFAULT_IRQ_WORK 256
9
10/* The datasheet for the X710 and XL710 indicate that the maximum value for
11 * the ITR is 8160usec which is then called out as 0xFF0 with a 2usec
12 * resolution. 8160 is 0x1FE0 when written out in hex. So instead of storing
13 * the register value which is divided by 2 lets use the actual values and
14 * avoid an excessive amount of translation.
15 */
16#define IAVF_ITR_DYNAMIC 0x8000 /* use top bit as a flag */
17#define IAVF_ITR_MASK 0x1FFE /* mask for ITR register value */
18#define IAVF_MIN_ITR 2 /* reg uses 2 usec resolution */
19#define IAVF_ITR_100K 10 /* all values below must be even */
20#define IAVF_ITR_50K 20
21#define IAVF_ITR_20K 50
22#define IAVF_ITR_18K 60
23#define IAVF_ITR_8K 122
24#define IAVF_MAX_ITR 8160 /* maximum value as per datasheet */
25#define ITR_TO_REG(setting) ((setting) & ~IAVF_ITR_DYNAMIC)
26#define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~IAVF_ITR_MASK)
27#define ITR_IS_DYNAMIC(setting) (!!((setting) & IAVF_ITR_DYNAMIC))
28
29#define IAVF_ITR_RX_DEF (IAVF_ITR_20K | IAVF_ITR_DYNAMIC)
30#define IAVF_ITR_TX_DEF (IAVF_ITR_20K | IAVF_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 IAVF_MAX_INTRL 0x3B /* reg uses 4 usec resolution */
37#define INTRL_REG_TO_USEC(intrl) ((intrl & ~INTRL_ENA) << 2)
38#define INTRL_USEC_TO_REG(set) ((set) ? ((set) >> 2) | INTRL_ENA : 0)
39#define IAVF_INTRL_8K 125 /* 8000 ints/sec */
40#define IAVF_INTRL_62K 16 /* 62500 ints/sec */
41#define IAVF_INTRL_83K 12 /* 83333 ints/sec */
42
43#define IAVF_QUEUE_END_OF_LIST 0x7FF
44
45/* this enum matches hardware bits and is meant to be used by DYN_CTLN
46 * registers and QINT registers or more generally anywhere in the manual
47 * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any
48 * register but instead is a special value meaning "don't update" ITR0/1/2.
49 */
50enum iavf_dyn_idx_t {
51 IAVF_IDX_ITR0 = 0,
52 IAVF_IDX_ITR1 = 1,
53 IAVF_IDX_ITR2 = 2,
54 IAVF_ITR_NONE = 3 /* ITR_NONE must not be used as an index */
55};
56
57/* these are indexes into ITRN registers */
58#define IAVF_RX_ITR IAVF_IDX_ITR0
59#define IAVF_TX_ITR IAVF_IDX_ITR1
60#define IAVF_PE_ITR IAVF_IDX_ITR2
61
62/* Supported RSS offloads */
63#define IAVF_DEFAULT_RSS_HENA ( \
64 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_UDP) | \
65 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_SCTP) | \
66 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_TCP) | \
67 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_OTHER) | \
68 BIT_ULL(IAVF_FILTER_PCTYPE_FRAG_IPV4) | \
69 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_UDP) | \
70 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_TCP) | \
71 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_SCTP) | \
72 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_OTHER) | \
73 BIT_ULL(IAVF_FILTER_PCTYPE_FRAG_IPV6) | \
74 BIT_ULL(IAVF_FILTER_PCTYPE_L2_PAYLOAD))
75
76#define IAVF_DEFAULT_RSS_HENA_EXPANDED (IAVF_DEFAULT_RSS_HENA | \
77 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \
78 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \
79 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \
80 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \
81 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \
82 BIT_ULL(IAVF_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP))
83
84/* Supported Rx Buffer Sizes (a multiple of 128) */
85#define IAVF_RXBUFFER_256 256
86#define IAVF_RXBUFFER_1536 1536 /* 128B aligned standard Ethernet frame */
87#define IAVF_RXBUFFER_2048 2048
88#define IAVF_RXBUFFER_3072 3072 /* Used for large frames w/ padding */
89#define IAVF_MAX_RXBUFFER 9728 /* largest size for single descriptor */
90
91/* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we
92 * reserve 2 more, and skb_shared_info adds an additional 384 bytes more,
93 * this adds up to 512 bytes of extra data meaning the smallest allocation
94 * we could have is 1K.
95 * i.e. RXBUFFER_256 --> 960 byte skb (size-1024 slab)
96 * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab)
97 */
98#define IAVF_RX_HDR_SIZE IAVF_RXBUFFER_256
99#define IAVF_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))
100#define iavf_rx_desc iavf_32byte_rx_desc
101
102#define IAVF_RX_DMA_ATTR \
103 (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING)
104
105/* Attempt to maximize the headroom available for incoming frames. We
106 * use a 2K buffer for receives and need 1536/1534 to store the data for
107 * the frame. This leaves us with 512 bytes of room. From that we need
108 * to deduct the space needed for the shared info and the padding needed
109 * to IP align the frame.
110 *
111 * Note: For cache line sizes 256 or larger this value is going to end
112 * up negative. In these cases we should fall back to the legacy
113 * receive path.
114 */
115#if (PAGE_SIZE < 8192)
116#define IAVF_2K_TOO_SMALL_WITH_PADDING \
117((NET_SKB_PAD + IAVF_RXBUFFER_1536) > SKB_WITH_OVERHEAD(IAVF_RXBUFFER_2048))
118
119static inline int iavf_compute_pad(int rx_buf_len)
120{
121 int page_size, pad_size;
122
123 page_size = ALIGN(rx_buf_len, PAGE_SIZE / 2);
124 pad_size = SKB_WITH_OVERHEAD(page_size) - rx_buf_len;
125
126 return pad_size;
127}
128
129static inline int iavf_skb_pad(void)
130{
131 int rx_buf_len;
132
133 /* If a 2K buffer cannot handle a standard Ethernet frame then
134 * optimize padding for a 3K buffer instead of a 1.5K buffer.
135 *
136 * For a 3K buffer we need to add enough padding to allow for
137 * tailroom due to NET_IP_ALIGN possibly shifting us out of
138 * cache-line alignment.
139 */
140 if (IAVF_2K_TOO_SMALL_WITH_PADDING)
141 rx_buf_len = IAVF_RXBUFFER_3072 + SKB_DATA_ALIGN(NET_IP_ALIGN);
142 else
143 rx_buf_len = IAVF_RXBUFFER_1536;
144
145 /* if needed make room for NET_IP_ALIGN */
146 rx_buf_len -= NET_IP_ALIGN;
147
148 return iavf_compute_pad(rx_buf_len);
149}
150
151#define IAVF_SKB_PAD iavf_skb_pad()
152#else
153#define IAVF_2K_TOO_SMALL_WITH_PADDING false
154#define IAVF_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)
155#endif
156
157/**
158 * iavf_test_staterr - tests bits in Rx descriptor status and error fields
159 * @rx_desc: pointer to receive descriptor (in le64 format)
160 * @stat_err_bits: value to mask
161 *
162 * This function does some fast chicanery in order to return the
163 * value of the mask which is really only used for boolean tests.
164 * The status_error_len doesn't need to be shifted because it begins
165 * at offset zero.
166 */
167static inline bool iavf_test_staterr(union iavf_rx_desc *rx_desc,
168 const u64 stat_err_bits)
169{
170 return !!(rx_desc->wb.qword1.status_error_len &
171 cpu_to_le64(stat_err_bits));
172}
173
174/* How many Rx Buffers do we bundle into one write to the hardware ? */
175#define IAVF_RX_INCREMENT(r, i) \
176 do { \
177 (i)++; \
178 if ((i) == (r)->count) \
179 i = 0; \
180 r->next_to_clean = i; \
181 } while (0)
182
183#define IAVF_RX_NEXT_DESC(r, i, n) \
184 do { \
185 (i)++; \
186 if ((i) == (r)->count) \
187 i = 0; \
188 (n) = IAVF_RX_DESC((r), (i)); \
189 } while (0)
190
191#define IAVF_RX_NEXT_DESC_PREFETCH(r, i, n) \
192 do { \
193 IAVF_RX_NEXT_DESC((r), (i), (n)); \
194 prefetch((n)); \
195 } while (0)
196
197#define IAVF_MAX_BUFFER_TXD 8
198#define IAVF_MIN_TX_LEN 17
199
200/* The size limit for a transmit buffer in a descriptor is (16K - 1).
201 * In order to align with the read requests we will align the value to
202 * the nearest 4K which represents our maximum read request size.
203 */
204#define IAVF_MAX_READ_REQ_SIZE 4096
205#define IAVF_MAX_DATA_PER_TXD (16 * 1024 - 1)
206#define IAVF_MAX_DATA_PER_TXD_ALIGNED \
207 (IAVF_MAX_DATA_PER_TXD & ~(IAVF_MAX_READ_REQ_SIZE - 1))
208
209/**
210 * iavf_txd_use_count - estimate the number of descriptors needed for Tx
211 * @size: transmit request size in bytes
212 *
213 * Due to hardware alignment restrictions (4K alignment), we need to
214 * assume that we can have no more than 12K of data per descriptor, even
215 * though each descriptor can take up to 16K - 1 bytes of aligned memory.
216 * Thus, we need to divide by 12K. But division is slow! Instead,
217 * we decompose the operation into shifts and one relatively cheap
218 * multiply operation.
219 *
220 * To divide by 12K, we first divide by 4K, then divide by 3:
221 * To divide by 4K, shift right by 12 bits
222 * To divide by 3, multiply by 85, then divide by 256
223 * (Divide by 256 is done by shifting right by 8 bits)
224 * Finally, we add one to round up. Because 256 isn't an exact multiple of
225 * 3, we'll underestimate near each multiple of 12K. This is actually more
226 * accurate as we have 4K - 1 of wiggle room that we can fit into the last
227 * segment. For our purposes this is accurate out to 1M which is orders of
228 * magnitude greater than our largest possible GSO size.
229 *
230 * This would then be implemented as:
231 * return (((size >> 12) * 85) >> 8) + 1;
232 *
233 * Since multiplication and division are commutative, we can reorder
234 * operations into:
235 * return ((size * 85) >> 20) + 1;
236 */
237static inline unsigned int iavf_txd_use_count(unsigned int size)
238{
239 return ((size * 85) >> 20) + 1;
240}
241
242/* Tx Descriptors needed, worst case */
243#define DESC_NEEDED (MAX_SKB_FRAGS + 6)
244#define IAVF_MIN_DESC_PENDING 4
245
246#define IAVF_TX_FLAGS_HW_VLAN BIT(1)
247#define IAVF_TX_FLAGS_SW_VLAN BIT(2)
248#define IAVF_TX_FLAGS_TSO BIT(3)
249#define IAVF_TX_FLAGS_IPV4 BIT(4)
250#define IAVF_TX_FLAGS_IPV6 BIT(5)
251#define IAVF_TX_FLAGS_FCCRC BIT(6)
252#define IAVF_TX_FLAGS_FSO BIT(7)
253#define IAVF_TX_FLAGS_FD_SB BIT(9)
254#define IAVF_TX_FLAGS_VXLAN_TUNNEL BIT(10)
255#define IAVF_TX_FLAGS_HW_OUTER_SINGLE_VLAN BIT(11)
256#define IAVF_TX_FLAGS_VLAN_MASK 0xffff0000
257#define IAVF_TX_FLAGS_VLAN_PRIO_MASK 0xe0000000
258#define IAVF_TX_FLAGS_VLAN_PRIO_SHIFT 29
259#define IAVF_TX_FLAGS_VLAN_SHIFT 16
260
261struct iavf_tx_buffer {
262 struct iavf_tx_desc *next_to_watch;
263 union {
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
275struct iavf_rx_buffer {
276 dma_addr_t dma;
277 struct page *page;
278#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
279 __u32 page_offset;
280#else
281 __u16 page_offset;
282#endif
283 __u16 pagecnt_bias;
284};
285
286struct iavf_queue_stats {
287 u64 packets;
288 u64 bytes;
289};
290
291struct iavf_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 int prev_pkt_ctr;
298 u64 tx_lost_interrupt;
299};
300
301struct iavf_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 realloc_count;
307};
308
309enum iavf_ring_state_t {
310 __IAVF_TX_FDIR_INIT_DONE,
311 __IAVF_TX_XPS_INIT_DONE,
312 __IAVF_RING_STATE_NBITS /* must be last */
313};
314
315/* some useful defines for virtchannel interface, which
316 * is the only remaining user of header split
317 */
318#define IAVF_RX_DTYPE_NO_SPLIT 0
319#define IAVF_RX_DTYPE_HEADER_SPLIT 1
320#define IAVF_RX_DTYPE_SPLIT_ALWAYS 2
321#define IAVF_RX_SPLIT_L2 0x1
322#define IAVF_RX_SPLIT_IP 0x2
323#define IAVF_RX_SPLIT_TCP_UDP 0x4
324#define IAVF_RX_SPLIT_SCTP 0x8
325
326/* struct that defines a descriptor ring, associated with a VSI */
327struct iavf_ring {
328 struct iavf_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 union {
333 struct iavf_tx_buffer *tx_bi;
334 struct iavf_rx_buffer *rx_bi;
335 };
336 DECLARE_BITMAP(state, __IAVF_RING_STATE_NBITS);
337 u16 queue_index; /* Queue number of ring */
338 u8 dcb_tc; /* Traffic class of ring */
339 u8 __iomem *tail;
340
341 /* high bit set means dynamic, use accessors routines to read/write.
342 * hardware only supports 2us resolution for the ITR registers.
343 * these values always store the USER setting, and must be converted
344 * before programming to a register.
345 */
346 u16 itr_setting;
347
348 u16 count; /* Number of descriptors */
349 u16 reg_idx; /* HW register index of the ring */
350 u16 rx_buf_len;
351
352 /* used in interrupt processing */
353 u16 next_to_use;
354 u16 next_to_clean;
355
356 u8 atr_sample_rate;
357 u8 atr_count;
358
359 bool ring_active; /* is ring online or not */
360 bool arm_wb; /* do something to arm write back */
361 u8 packet_stride;
362
363 u16 flags;
364#define IAVF_TXR_FLAGS_WB_ON_ITR BIT(0)
365#define IAVF_RXR_FLAGS_BUILD_SKB_ENABLED BIT(1)
366#define IAVF_TXRX_FLAGS_VLAN_TAG_LOC_L2TAG1 BIT(3)
367#define IAVF_TXR_FLAGS_VLAN_TAG_LOC_L2TAG2 BIT(4)
368#define IAVF_RXR_FLAGS_VLAN_TAG_LOC_L2TAG2_2 BIT(5)
369
370 /* stats structs */
371 struct iavf_queue_stats stats;
372 struct u64_stats_sync syncp;
373 union {
374 struct iavf_tx_queue_stats tx_stats;
375 struct iavf_rx_queue_stats rx_stats;
376 };
377
378 unsigned int size; /* length of descriptor ring in bytes */
379 dma_addr_t dma; /* physical address of ring */
380
381 struct iavf_vsi *vsi; /* Backreference to associated VSI */
382 struct iavf_q_vector *q_vector; /* Backreference to associated vector */
383
384 struct rcu_head rcu; /* to avoid race on free */
385 u16 next_to_alloc;
386 struct sk_buff *skb; /* When iavf_clean_rx_ring_irq() must
387 * return before it sees the EOP for
388 * the current packet, we save that skb
389 * here and resume receiving this
390 * packet the next time
391 * iavf_clean_rx_ring_irq() is called
392 * for this ring.
393 */
394} ____cacheline_internodealigned_in_smp;
395
396static inline bool ring_uses_build_skb(struct iavf_ring *ring)
397{
398 return !!(ring->flags & IAVF_RXR_FLAGS_BUILD_SKB_ENABLED);
399}
400
401static inline void set_ring_build_skb_enabled(struct iavf_ring *ring)
402{
403 ring->flags |= IAVF_RXR_FLAGS_BUILD_SKB_ENABLED;
404}
405
406static inline void clear_ring_build_skb_enabled(struct iavf_ring *ring)
407{
408 ring->flags &= ~IAVF_RXR_FLAGS_BUILD_SKB_ENABLED;
409}
410
411#define IAVF_ITR_ADAPTIVE_MIN_INC 0x0002
412#define IAVF_ITR_ADAPTIVE_MIN_USECS 0x0002
413#define IAVF_ITR_ADAPTIVE_MAX_USECS 0x007e
414#define IAVF_ITR_ADAPTIVE_LATENCY 0x8000
415#define IAVF_ITR_ADAPTIVE_BULK 0x0000
416#define ITR_IS_BULK(x) (!((x) & IAVF_ITR_ADAPTIVE_LATENCY))
417
418struct iavf_ring_container {
419 struct iavf_ring *ring; /* pointer to linked list of ring(s) */
420 unsigned long next_update; /* jiffies value of next update */
421 unsigned int total_bytes; /* total bytes processed this int */
422 unsigned int total_packets; /* total packets processed this int */
423 u16 count;
424 u16 target_itr; /* target ITR setting for ring(s) */
425 u16 current_itr; /* current ITR setting for ring(s) */
426};
427
428/* iterator for handling rings in ring container */
429#define iavf_for_each_ring(pos, head) \
430 for (pos = (head).ring; pos != NULL; pos = pos->next)
431
432static inline unsigned int iavf_rx_pg_order(struct iavf_ring *ring)
433{
434#if (PAGE_SIZE < 8192)
435 if (ring->rx_buf_len > (PAGE_SIZE / 2))
436 return 1;
437#endif
438 return 0;
439}
440
441#define iavf_rx_pg_size(_ring) (PAGE_SIZE << iavf_rx_pg_order(_ring))
442
443bool iavf_alloc_rx_buffers(struct iavf_ring *rxr, u16 cleaned_count);
444netdev_tx_t iavf_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
445int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring);
446int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring);
447void iavf_free_tx_resources(struct iavf_ring *tx_ring);
448void iavf_free_rx_resources(struct iavf_ring *rx_ring);
449int iavf_napi_poll(struct napi_struct *napi, int budget);
450void iavf_detect_recover_hung(struct iavf_vsi *vsi);
451int __iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size);
452bool __iavf_chk_linearize(struct sk_buff *skb);
453
454/**
455 * iavf_xmit_descriptor_count - calculate number of Tx descriptors needed
456 * @skb: send buffer
457 *
458 * Returns number of data descriptors needed for this skb. Returns 0 to indicate
459 * there is not enough descriptors available in this ring since we need at least
460 * one descriptor.
461 **/
462static inline int iavf_xmit_descriptor_count(struct sk_buff *skb)
463{
464 const skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
465 unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
466 int count = 0, size = skb_headlen(skb);
467
468 for (;;) {
469 count += iavf_txd_use_count(size);
470
471 if (!nr_frags--)
472 break;
473
474 size = skb_frag_size(frag: frag++);
475 }
476
477 return count;
478}
479
480/**
481 * iavf_maybe_stop_tx - 1st level check for Tx stop conditions
482 * @tx_ring: the ring to be checked
483 * @size: the size buffer we want to assure is available
484 *
485 * Returns 0 if stop is not needed
486 **/
487static inline int iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size)
488{
489 if (likely(IAVF_DESC_UNUSED(tx_ring) >= size))
490 return 0;
491 return __iavf_maybe_stop_tx(tx_ring, size);
492}
493
494/**
495 * iavf_chk_linearize - Check if there are more than 8 fragments per packet
496 * @skb: send buffer
497 * @count: number of buffers used
498 *
499 * Note: Our HW can't scatter-gather more than 8 fragments to build
500 * a packet on the wire and so we need to figure out the cases where we
501 * need to linearize the skb.
502 **/
503static inline bool iavf_chk_linearize(struct sk_buff *skb, int count)
504{
505 /* Both TSO and single send will work if count is less than 8 */
506 if (likely(count < IAVF_MAX_BUFFER_TXD))
507 return false;
508
509 if (skb_is_gso(skb))
510 return __iavf_chk_linearize(skb);
511
512 /* we can support up to 8 data buffers for a single send */
513 return count != IAVF_MAX_BUFFER_TXD;
514}
515/**
516 * txring_txq - helper to convert from a ring to a queue
517 * @ring: Tx ring to find the netdev equivalent of
518 **/
519static inline struct netdev_queue *txring_txq(const struct iavf_ring *ring)
520{
521 return netdev_get_tx_queue(dev: ring->netdev, index: ring->queue_index);
522}
523#endif /* _IAVF_TXRX_H_ */
524

source code of linux/drivers/net/ethernet/intel/iavf/iavf_txrx.h