xref: /linux/drivers/net/ethernet/intel/iavf/iavf_txrx.h (revision 97cadd3d3ce3df32647011233a35a1597bb7a55b)
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_ITR_100K		    10	/* all values below must be even */
19 #define IAVF_ITR_50K		    20
20 #define IAVF_ITR_20K		    50
21 #define IAVF_ITR_18K		    60
22 #define IAVF_ITR_8K		   122
23 #define IAVF_MAX_ITR		  8160	/* maximum value as per datasheet */
24 #define ITR_TO_REG(setting) ((setting) & ~IAVF_ITR_DYNAMIC)
25 #define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~IAVF_ITR_MASK)
26 #define ITR_IS_DYNAMIC(setting) (!!((setting) & IAVF_ITR_DYNAMIC))
27 
28 #define IAVF_ITR_RX_DEF		(IAVF_ITR_20K | IAVF_ITR_DYNAMIC)
29 #define IAVF_ITR_TX_DEF		(IAVF_ITR_20K | IAVF_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 IAVF_MAX_INTRL             0x3B    /* reg uses 4 usec resolution */
36 #define INTRL_REG_TO_USEC(intrl) ((intrl & ~INTRL_ENA) << 2)
37 #define INTRL_USEC_TO_REG(set) ((set) ? ((set) >> 2) | INTRL_ENA : 0)
38 #define IAVF_INTRL_8K              125     /* 8000 ints/sec */
39 #define IAVF_INTRL_62K             16      /* 62500 ints/sec */
40 #define IAVF_INTRL_83K             12      /* 83333 ints/sec */
41 
42 #define IAVF_QUEUE_END_OF_LIST 0x7FF
43 
44 /* this enum matches hardware bits and is meant to be used by DYN_CTLN
45  * registers and QINT registers or more generally anywhere in the manual
46  * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any
47  * register but instead is a special value meaning "don't update" ITR0/1/2.
48  */
49 enum iavf_dyn_idx_t {
50 	IAVF_IDX_ITR0 = 0,
51 	IAVF_IDX_ITR1 = 1,
52 	IAVF_IDX_ITR2 = 2,
53 	IAVF_ITR_NONE = 3	/* ITR_NONE must not be used as an index */
54 };
55 
56 /* these are indexes into ITRN registers */
57 #define IAVF_RX_ITR    IAVF_IDX_ITR0
58 #define IAVF_TX_ITR    IAVF_IDX_ITR1
59 #define IAVF_PE_ITR    IAVF_IDX_ITR2
60 
61 /* Supported RSS offloads */
62 #define IAVF_DEFAULT_RSS_HENA ( \
63 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_UDP) | \
64 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_SCTP) | \
65 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_TCP) | \
66 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_OTHER) | \
67 	BIT_ULL(IAVF_FILTER_PCTYPE_FRAG_IPV4) | \
68 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_UDP) | \
69 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_TCP) | \
70 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_SCTP) | \
71 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_OTHER) | \
72 	BIT_ULL(IAVF_FILTER_PCTYPE_FRAG_IPV6) | \
73 	BIT_ULL(IAVF_FILTER_PCTYPE_L2_PAYLOAD))
74 
75 #define IAVF_DEFAULT_RSS_HENA_EXPANDED (IAVF_DEFAULT_RSS_HENA | \
76 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \
77 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \
78 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \
79 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \
80 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \
81 	BIT_ULL(IAVF_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP))
82 
83 /* Supported Rx Buffer Sizes (a multiple of 128) */
84 #define IAVF_RXBUFFER_3072  3072  /* Used for large frames w/ padding */
85 #define IAVF_MAX_RXBUFFER   9728  /* largest size for single descriptor */
86 
87 #define IAVF_PACKET_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))
88 #define iavf_rx_desc iavf_32byte_rx_desc
89 
90 #define IAVF_RX_DMA_ATTR \
91 	(DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING)
92 
93 #define IAVF_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)
94 
95 /**
96  * iavf_test_staterr - tests bits in Rx descriptor status and error fields
97  * @rx_desc: pointer to receive descriptor (in le64 format)
98  * @stat_err_bits: value to mask
99  *
100  * This function does some fast chicanery in order to return the
101  * value of the mask which is really only used for boolean tests.
102  * The status_error_len doesn't need to be shifted because it begins
103  * at offset zero.
104  */
105 static inline bool iavf_test_staterr(union iavf_rx_desc *rx_desc,
106 				     const u64 stat_err_bits)
107 {
108 	return !!(rx_desc->wb.qword1.status_error_len &
109 		  cpu_to_le64(stat_err_bits));
110 }
111 
112 /* How many Rx Buffers do we bundle into one write to the hardware ? */
113 #define IAVF_RX_INCREMENT(r, i) \
114 	do {					\
115 		(i)++;				\
116 		if ((i) == (r)->count)		\
117 			i = 0;			\
118 		r->next_to_clean = i;		\
119 	} while (0)
120 
121 #define IAVF_RX_NEXT_DESC(r, i, n)		\
122 	do {					\
123 		(i)++;				\
124 		if ((i) == (r)->count)		\
125 			i = 0;			\
126 		(n) = IAVF_RX_DESC((r), (i));	\
127 	} while (0)
128 
129 #define IAVF_RX_NEXT_DESC_PREFETCH(r, i, n)		\
130 	do {						\
131 		IAVF_RX_NEXT_DESC((r), (i), (n));	\
132 		prefetch((n));				\
133 	} while (0)
134 
135 #define IAVF_MAX_BUFFER_TXD	8
136 #define IAVF_MIN_TX_LEN		17
137 
138 /* The size limit for a transmit buffer in a descriptor is (16K - 1).
139  * In order to align with the read requests we will align the value to
140  * the nearest 4K which represents our maximum read request size.
141  */
142 #define IAVF_MAX_READ_REQ_SIZE		4096
143 #define IAVF_MAX_DATA_PER_TXD		(16 * 1024 - 1)
144 #define IAVF_MAX_DATA_PER_TXD_ALIGNED \
145 	(IAVF_MAX_DATA_PER_TXD & ~(IAVF_MAX_READ_REQ_SIZE - 1))
146 
147 /**
148  * iavf_txd_use_count  - estimate the number of descriptors needed for Tx
149  * @size: transmit request size in bytes
150  *
151  * Due to hardware alignment restrictions (4K alignment), we need to
152  * assume that we can have no more than 12K of data per descriptor, even
153  * though each descriptor can take up to 16K - 1 bytes of aligned memory.
154  * Thus, we need to divide by 12K. But division is slow! Instead,
155  * we decompose the operation into shifts and one relatively cheap
156  * multiply operation.
157  *
158  * To divide by 12K, we first divide by 4K, then divide by 3:
159  *     To divide by 4K, shift right by 12 bits
160  *     To divide by 3, multiply by 85, then divide by 256
161  *     (Divide by 256 is done by shifting right by 8 bits)
162  * Finally, we add one to round up. Because 256 isn't an exact multiple of
163  * 3, we'll underestimate near each multiple of 12K. This is actually more
164  * accurate as we have 4K - 1 of wiggle room that we can fit into the last
165  * segment.  For our purposes this is accurate out to 1M which is orders of
166  * magnitude greater than our largest possible GSO size.
167  *
168  * This would then be implemented as:
169  *     return (((size >> 12) * 85) >> 8) + 1;
170  *
171  * Since multiplication and division are commutative, we can reorder
172  * operations into:
173  *     return ((size * 85) >> 20) + 1;
174  */
175 static inline unsigned int iavf_txd_use_count(unsigned int size)
176 {
177 	return ((size * 85) >> 20) + 1;
178 }
179 
180 /* Tx Descriptors needed, worst case */
181 #define DESC_NEEDED (MAX_SKB_FRAGS + 6)
182 #define IAVF_MIN_DESC_PENDING	4
183 
184 #define IAVF_TX_FLAGS_HW_VLAN			BIT(1)
185 #define IAVF_TX_FLAGS_SW_VLAN			BIT(2)
186 #define IAVF_TX_FLAGS_TSO			BIT(3)
187 #define IAVF_TX_FLAGS_IPV4			BIT(4)
188 #define IAVF_TX_FLAGS_IPV6			BIT(5)
189 #define IAVF_TX_FLAGS_FCCRC			BIT(6)
190 #define IAVF_TX_FLAGS_FSO			BIT(7)
191 #define IAVF_TX_FLAGS_FD_SB			BIT(9)
192 #define IAVF_TX_FLAGS_VXLAN_TUNNEL		BIT(10)
193 #define IAVF_TX_FLAGS_HW_OUTER_SINGLE_VLAN	BIT(11)
194 #define IAVF_TX_FLAGS_VLAN_MASK			0xffff0000
195 #define IAVF_TX_FLAGS_VLAN_PRIO_MASK		0xe0000000
196 #define IAVF_TX_FLAGS_VLAN_PRIO_SHIFT		29
197 #define IAVF_TX_FLAGS_VLAN_SHIFT		16
198 
199 struct iavf_tx_buffer {
200 	struct iavf_tx_desc *next_to_watch;
201 	union {
202 		struct sk_buff *skb;
203 		void *raw_buf;
204 	};
205 	unsigned int bytecount;
206 	unsigned short gso_segs;
207 
208 	DEFINE_DMA_UNMAP_ADDR(dma);
209 	DEFINE_DMA_UNMAP_LEN(len);
210 	u32 tx_flags;
211 };
212 
213 struct iavf_rx_buffer {
214 	dma_addr_t dma;
215 	struct page *page;
216 	__u32 page_offset;
217 };
218 
219 struct iavf_queue_stats {
220 	u64 packets;
221 	u64 bytes;
222 };
223 
224 struct iavf_tx_queue_stats {
225 	u64 restart_queue;
226 	u64 tx_busy;
227 	u64 tx_done_old;
228 	u64 tx_linearize;
229 	u64 tx_force_wb;
230 	u64 tx_lost_interrupt;
231 };
232 
233 struct iavf_rx_queue_stats {
234 	u64 non_eop_descs;
235 	u64 alloc_page_failed;
236 	u64 alloc_buff_failed;
237 };
238 
239 /* some useful defines for virtchannel interface, which
240  * is the only remaining user of header split
241  */
242 #define IAVF_RX_DTYPE_NO_SPLIT      0
243 #define IAVF_RX_DTYPE_HEADER_SPLIT  1
244 #define IAVF_RX_DTYPE_SPLIT_ALWAYS  2
245 #define IAVF_RX_SPLIT_L2      0x1
246 #define IAVF_RX_SPLIT_IP      0x2
247 #define IAVF_RX_SPLIT_TCP_UDP 0x4
248 #define IAVF_RX_SPLIT_SCTP    0x8
249 
250 /* struct that defines a descriptor ring, associated with a VSI */
251 struct iavf_ring {
252 	struct iavf_ring *next;		/* pointer to next ring in q_vector */
253 	void *desc;			/* Descriptor ring memory */
254 	struct device *dev;		/* Used for DMA mapping */
255 	struct net_device *netdev;	/* netdev ring maps to */
256 	union {
257 		struct iavf_tx_buffer *tx_bi;
258 		struct iavf_rx_buffer *rx_bi;
259 	};
260 	u8 __iomem *tail;
261 	u16 queue_index;		/* Queue number of ring */
262 
263 	/* high bit set means dynamic, use accessors routines to read/write.
264 	 * hardware only supports 2us resolution for the ITR registers.
265 	 * these values always store the USER setting, and must be converted
266 	 * before programming to a register.
267 	 */
268 	u16 itr_setting;
269 
270 	u16 count;			/* Number of descriptors */
271 
272 	/* used in interrupt processing */
273 	u16 next_to_use;
274 	u16 next_to_clean;
275 
276 	u16 flags;
277 #define IAVF_TXR_FLAGS_WB_ON_ITR		BIT(0)
278 #define IAVF_TXR_FLAGS_ARM_WB			BIT(1)
279 /* BIT(2) is free */
280 #define IAVF_TXRX_FLAGS_VLAN_TAG_LOC_L2TAG1	BIT(3)
281 #define IAVF_TXR_FLAGS_VLAN_TAG_LOC_L2TAG2	BIT(4)
282 #define IAVF_RXR_FLAGS_VLAN_TAG_LOC_L2TAG2_2	BIT(5)
283 
284 	/* stats structs */
285 	struct iavf_queue_stats	stats;
286 	struct u64_stats_sync syncp;
287 	union {
288 		struct iavf_tx_queue_stats tx_stats;
289 		struct iavf_rx_queue_stats rx_stats;
290 	};
291 
292 	int prev_pkt_ctr;		/* For Tx stall detection */
293 	unsigned int size;		/* length of descriptor ring in bytes */
294 	dma_addr_t dma;			/* physical address of ring */
295 
296 	struct iavf_vsi *vsi;		/* Backreference to associated VSI */
297 	struct iavf_q_vector *q_vector;	/* Backreference to associated vector */
298 
299 	struct rcu_head rcu;		/* to avoid race on free */
300 	struct sk_buff *skb;		/* When iavf_clean_rx_ring_irq() must
301 					 * return before it sees the EOP for
302 					 * the current packet, we save that skb
303 					 * here and resume receiving this
304 					 * packet the next time
305 					 * iavf_clean_rx_ring_irq() is called
306 					 * for this ring.
307 					 */
308 } ____cacheline_internodealigned_in_smp;
309 
310 #define IAVF_ITR_ADAPTIVE_MIN_INC	0x0002
311 #define IAVF_ITR_ADAPTIVE_MIN_USECS	0x0002
312 #define IAVF_ITR_ADAPTIVE_MAX_USECS	0x007e
313 #define IAVF_ITR_ADAPTIVE_LATENCY	0x8000
314 #define IAVF_ITR_ADAPTIVE_BULK		0x0000
315 #define ITR_IS_BULK(x) (!((x) & IAVF_ITR_ADAPTIVE_LATENCY))
316 
317 struct iavf_ring_container {
318 	struct iavf_ring *ring;		/* pointer to linked list of ring(s) */
319 	unsigned long next_update;	/* jiffies value of next update */
320 	unsigned int total_bytes;	/* total bytes processed this int */
321 	unsigned int total_packets;	/* total packets processed this int */
322 	u16 count;
323 	u16 target_itr;			/* target ITR setting for ring(s) */
324 	u16 current_itr;		/* current ITR setting for ring(s) */
325 };
326 
327 /* iterator for handling rings in ring container */
328 #define iavf_for_each_ring(pos, head) \
329 	for (pos = (head).ring; pos != NULL; pos = pos->next)
330 
331 static inline unsigned int iavf_rx_pg_order(struct iavf_ring *ring)
332 {
333 	return 0;
334 }
335 
336 #define iavf_rx_pg_size(_ring) (PAGE_SIZE << iavf_rx_pg_order(_ring))
337 
338 bool iavf_alloc_rx_buffers(struct iavf_ring *rxr, u16 cleaned_count);
339 netdev_tx_t iavf_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
340 int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring);
341 int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring);
342 void iavf_free_tx_resources(struct iavf_ring *tx_ring);
343 void iavf_free_rx_resources(struct iavf_ring *rx_ring);
344 int iavf_napi_poll(struct napi_struct *napi, int budget);
345 void iavf_detect_recover_hung(struct iavf_vsi *vsi);
346 int __iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size);
347 bool __iavf_chk_linearize(struct sk_buff *skb);
348 
349 /**
350  * iavf_xmit_descriptor_count - calculate number of Tx descriptors needed
351  * @skb:     send buffer
352  *
353  * Returns number of data descriptors needed for this skb. Returns 0 to indicate
354  * there is not enough descriptors available in this ring since we need at least
355  * one descriptor.
356  **/
357 static inline int iavf_xmit_descriptor_count(struct sk_buff *skb)
358 {
359 	const skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
360 	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
361 	int count = 0, size = skb_headlen(skb);
362 
363 	for (;;) {
364 		count += iavf_txd_use_count(size);
365 
366 		if (!nr_frags--)
367 			break;
368 
369 		size = skb_frag_size(frag++);
370 	}
371 
372 	return count;
373 }
374 
375 /**
376  * iavf_maybe_stop_tx - 1st level check for Tx stop conditions
377  * @tx_ring: the ring to be checked
378  * @size:    the size buffer we want to assure is available
379  *
380  * Returns 0 if stop is not needed
381  **/
382 static inline int iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size)
383 {
384 	if (likely(IAVF_DESC_UNUSED(tx_ring) >= size))
385 		return 0;
386 	return __iavf_maybe_stop_tx(tx_ring, size);
387 }
388 
389 /**
390  * iavf_chk_linearize - Check if there are more than 8 fragments per packet
391  * @skb:      send buffer
392  * @count:    number of buffers used
393  *
394  * Note: Our HW can't scatter-gather more than 8 fragments to build
395  * a packet on the wire and so we need to figure out the cases where we
396  * need to linearize the skb.
397  **/
398 static inline bool iavf_chk_linearize(struct sk_buff *skb, int count)
399 {
400 	/* Both TSO and single send will work if count is less than 8 */
401 	if (likely(count < IAVF_MAX_BUFFER_TXD))
402 		return false;
403 
404 	if (skb_is_gso(skb))
405 		return __iavf_chk_linearize(skb);
406 
407 	/* we can support up to 8 data buffers for a single send */
408 	return count != IAVF_MAX_BUFFER_TXD;
409 }
410 /**
411  * txring_txq - helper to convert from a ring to a queue
412  * @ring: Tx ring to find the netdev equivalent of
413  **/
414 static inline struct netdev_queue *txring_txq(const struct iavf_ring *ring)
415 {
416 	return netdev_get_tx_queue(ring->netdev, ring->queue_index);
417 }
418 #endif /* _IAVF_TXRX_H_ */
419