1 /*******************************************************************************
2  *
3  * Intel Ethernet Controller XL710 Family Linux Driver
4  * Copyright(c) 2013 - 2016 Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along
16  * with this program.  If not, see <http://www.gnu.org/licenses/>.
17  *
18  * The full GNU General Public License is included in this distribution in
19  * the file called "COPYING".
20  *
21  * Contact Information:
22  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24  *
25  ******************************************************************************/
26 
27 #ifndef _I40E_TXRX_H_
28 #define _I40E_TXRX_H_
29 
30 /* Interrupt Throttling and Rate Limiting Goodies */
31 
32 #define I40E_MAX_ITR               0x0FF0  /* reg uses 2 usec resolution */
33 #define I40E_MIN_ITR               0x0001  /* reg uses 2 usec resolution */
34 #define I40E_ITR_100K              0x0005
35 #define I40E_ITR_50K               0x000A
36 #define I40E_ITR_20K               0x0019
37 #define I40E_ITR_18K               0x001B
38 #define I40E_ITR_8K                0x003E
39 #define I40E_ITR_4K                0x007A
40 #define I40E_MAX_INTRL             0x3B    /* reg uses 4 usec resolution */
41 #define I40E_ITR_RX_DEF            I40E_ITR_20K
42 #define I40E_ITR_TX_DEF            I40E_ITR_20K
43 #define I40E_ITR_DYNAMIC           0x8000  /* use top bit as a flag */
44 #define I40E_MIN_INT_RATE          250     /* ~= 1000000 / (I40E_MAX_ITR * 2) */
45 #define I40E_MAX_INT_RATE          500000  /* == 1000000 / (I40E_MIN_ITR * 2) */
46 #define I40E_DEFAULT_IRQ_WORK      256
47 #define ITR_TO_REG(setting) ((setting & ~I40E_ITR_DYNAMIC) >> 1)
48 #define ITR_IS_DYNAMIC(setting) (!!(setting & I40E_ITR_DYNAMIC))
49 #define ITR_REG_TO_USEC(itr_reg) (itr_reg << 1)
50 /* 0x40 is the enable bit for interrupt rate limiting, and must be set if
51  * the value of the rate limit is non-zero
52  */
53 #define INTRL_ENA                  BIT(6)
54 #define INTRL_REG_TO_USEC(intrl) ((intrl & ~INTRL_ENA) << 2)
55 /**
56  * i40e_intrl_usec_to_reg - convert interrupt rate limit to register
57  * @intrl: interrupt rate limit to convert
58  *
59  * This function converts a decimal interrupt rate limit to the appropriate
60  * register format expected by the firmware when setting interrupt rate limit.
61  */
62 static inline u16 i40e_intrl_usec_to_reg(int intrl)
63 {
64 	if (intrl >> 2)
65 		return ((intrl >> 2) | INTRL_ENA);
66 	else
67 		return 0;
68 }
69 #define I40E_INTRL_8K              125     /* 8000 ints/sec */
70 #define I40E_INTRL_62K             16      /* 62500 ints/sec */
71 #define I40E_INTRL_83K             12      /* 83333 ints/sec */
72 
73 #define I40E_QUEUE_END_OF_LIST 0x7FF
74 
75 /* this enum matches hardware bits and is meant to be used by DYN_CTLN
76  * registers and QINT registers or more generally anywhere in the manual
77  * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any
78  * register but instead is a special value meaning "don't update" ITR0/1/2.
79  */
80 enum i40e_dyn_idx_t {
81 	I40E_IDX_ITR0 = 0,
82 	I40E_IDX_ITR1 = 1,
83 	I40E_IDX_ITR2 = 2,
84 	I40E_ITR_NONE = 3	/* ITR_NONE must not be used as an index */
85 };
86 
87 /* these are indexes into ITRN registers */
88 #define I40E_RX_ITR    I40E_IDX_ITR0
89 #define I40E_TX_ITR    I40E_IDX_ITR1
90 #define I40E_PE_ITR    I40E_IDX_ITR2
91 
92 /* Supported RSS offloads */
93 #define I40E_DEFAULT_RSS_HENA ( \
94 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_UDP) | \
95 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_SCTP) | \
96 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP) | \
97 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_OTHER) | \
98 	BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV4) | \
99 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_UDP) | \
100 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP) | \
101 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_SCTP) | \
102 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_OTHER) | \
103 	BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV6) | \
104 	BIT_ULL(I40E_FILTER_PCTYPE_L2_PAYLOAD))
105 
106 #define I40E_DEFAULT_RSS_HENA_EXPANDED (I40E_DEFAULT_RSS_HENA | \
107 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \
108 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \
109 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \
110 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \
111 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \
112 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP))
113 
114 #define i40e_pf_get_default_rss_hena(pf) \
115 	(((pf)->flags & I40E_FLAG_MULTIPLE_TCP_UDP_RSS_PCTYPE) ? \
116 	  I40E_DEFAULT_RSS_HENA_EXPANDED : I40E_DEFAULT_RSS_HENA)
117 
118 /* Supported Rx Buffer Sizes (a multiple of 128) */
119 #define I40E_RXBUFFER_256   256
120 #define I40E_RXBUFFER_2048  2048
121 #define I40E_RXBUFFER_3072  3072   /* For FCoE MTU of 2158 */
122 #define I40E_RXBUFFER_4096  4096
123 #define I40E_RXBUFFER_8192  8192
124 #define I40E_MAX_RXBUFFER   9728  /* largest size for single descriptor */
125 
126 /* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we
127  * reserve 2 more, and skb_shared_info adds an additional 384 bytes more,
128  * this adds up to 512 bytes of extra data meaning the smallest allocation
129  * we could have is 1K.
130  * i.e. RXBUFFER_256 --> 960 byte skb (size-1024 slab)
131  * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab)
132  */
133 #define I40E_RX_HDR_SIZE I40E_RXBUFFER_256
134 #define i40e_rx_desc i40e_32byte_rx_desc
135 
136 /**
137  * i40e_test_staterr - tests bits in Rx descriptor status and error fields
138  * @rx_desc: pointer to receive descriptor (in le64 format)
139  * @stat_err_bits: value to mask
140  *
141  * This function does some fast chicanery in order to return the
142  * value of the mask which is really only used for boolean tests.
143  * The status_error_len doesn't need to be shifted because it begins
144  * at offset zero.
145  */
146 static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc,
147 				     const u64 stat_err_bits)
148 {
149 	return !!(rx_desc->wb.qword1.status_error_len &
150 		  cpu_to_le64(stat_err_bits));
151 }
152 
153 /* How many Rx Buffers do we bundle into one write to the hardware ? */
154 #define I40E_RX_BUFFER_WRITE	16	/* Must be power of 2 */
155 #define I40E_RX_INCREMENT(r, i) \
156 	do {					\
157 		(i)++;				\
158 		if ((i) == (r)->count)		\
159 			i = 0;			\
160 		r->next_to_clean = i;		\
161 	} while (0)
162 
163 #define I40E_RX_NEXT_DESC(r, i, n)		\
164 	do {					\
165 		(i)++;				\
166 		if ((i) == (r)->count)		\
167 			i = 0;			\
168 		(n) = I40E_RX_DESC((r), (i));	\
169 	} while (0)
170 
171 #define I40E_RX_NEXT_DESC_PREFETCH(r, i, n)		\
172 	do {						\
173 		I40E_RX_NEXT_DESC((r), (i), (n));	\
174 		prefetch((n));				\
175 	} while (0)
176 
177 #define I40E_MAX_BUFFER_TXD	8
178 #define I40E_MIN_TX_LEN		17
179 
180 /* The size limit for a transmit buffer in a descriptor is (16K - 1).
181  * In order to align with the read requests we will align the value to
182  * the nearest 4K which represents our maximum read request size.
183  */
184 #define I40E_MAX_READ_REQ_SIZE		4096
185 #define I40E_MAX_DATA_PER_TXD		(16 * 1024 - 1)
186 #define I40E_MAX_DATA_PER_TXD_ALIGNED \
187 	(I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1))
188 
189 /**
190  * i40e_txd_use_count  - estimate the number of descriptors needed for Tx
191  * @size: transmit request size in bytes
192  *
193  * Due to hardware alignment restrictions (4K alignment), we need to
194  * assume that we can have no more than 12K of data per descriptor, even
195  * though each descriptor can take up to 16K - 1 bytes of aligned memory.
196  * Thus, we need to divide by 12K. But division is slow! Instead,
197  * we decompose the operation into shifts and one relatively cheap
198  * multiply operation.
199  *
200  * To divide by 12K, we first divide by 4K, then divide by 3:
201  *     To divide by 4K, shift right by 12 bits
202  *     To divide by 3, multiply by 85, then divide by 256
203  *     (Divide by 256 is done by shifting right by 8 bits)
204  * Finally, we add one to round up. Because 256 isn't an exact multiple of
205  * 3, we'll underestimate near each multiple of 12K. This is actually more
206  * accurate as we have 4K - 1 of wiggle room that we can fit into the last
207  * segment.  For our purposes this is accurate out to 1M which is orders of
208  * magnitude greater than our largest possible GSO size.
209  *
210  * This would then be implemented as:
211  *     return (((size >> 12) * 85) >> 8) + 1;
212  *
213  * Since multiplication and division are commutative, we can reorder
214  * operations into:
215  *     return ((size * 85) >> 20) + 1;
216  */
217 static inline unsigned int i40e_txd_use_count(unsigned int size)
218 {
219 	return ((size * 85) >> 20) + 1;
220 }
221 
222 /* Tx Descriptors needed, worst case */
223 #define DESC_NEEDED (MAX_SKB_FRAGS + 4)
224 #define I40E_MIN_DESC_PENDING	4
225 
226 #define I40E_TX_FLAGS_HW_VLAN		BIT(1)
227 #define I40E_TX_FLAGS_SW_VLAN		BIT(2)
228 #define I40E_TX_FLAGS_TSO		BIT(3)
229 #define I40E_TX_FLAGS_IPV4		BIT(4)
230 #define I40E_TX_FLAGS_IPV6		BIT(5)
231 #define I40E_TX_FLAGS_FCCRC		BIT(6)
232 #define I40E_TX_FLAGS_FSO		BIT(7)
233 #define I40E_TX_FLAGS_TSYN		BIT(8)
234 #define I40E_TX_FLAGS_FD_SB		BIT(9)
235 #define I40E_TX_FLAGS_UDP_TUNNEL	BIT(10)
236 #define I40E_TX_FLAGS_VLAN_MASK		0xffff0000
237 #define I40E_TX_FLAGS_VLAN_PRIO_MASK	0xe0000000
238 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT	29
239 #define I40E_TX_FLAGS_VLAN_SHIFT	16
240 
241 struct i40e_tx_buffer {
242 	struct i40e_tx_desc *next_to_watch;
243 	union {
244 		struct sk_buff *skb;
245 		void *raw_buf;
246 	};
247 	unsigned int bytecount;
248 	unsigned short gso_segs;
249 
250 	DEFINE_DMA_UNMAP_ADDR(dma);
251 	DEFINE_DMA_UNMAP_LEN(len);
252 	u32 tx_flags;
253 };
254 
255 struct i40e_rx_buffer {
256 	dma_addr_t dma;
257 	struct page *page;
258 	unsigned int page_offset;
259 };
260 
261 struct i40e_queue_stats {
262 	u64 packets;
263 	u64 bytes;
264 };
265 
266 struct i40e_tx_queue_stats {
267 	u64 restart_queue;
268 	u64 tx_busy;
269 	u64 tx_done_old;
270 	u64 tx_linearize;
271 	u64 tx_force_wb;
272 	u64 tx_lost_interrupt;
273 };
274 
275 struct i40e_rx_queue_stats {
276 	u64 non_eop_descs;
277 	u64 alloc_page_failed;
278 	u64 alloc_buff_failed;
279 	u64 page_reuse_count;
280 	u64 realloc_count;
281 };
282 
283 enum i40e_ring_state_t {
284 	__I40E_TX_FDIR_INIT_DONE,
285 	__I40E_TX_XPS_INIT_DONE,
286 };
287 
288 /* some useful defines for virtchannel interface, which
289  * is the only remaining user of header split
290  */
291 #define I40E_RX_DTYPE_NO_SPLIT      0
292 #define I40E_RX_DTYPE_HEADER_SPLIT  1
293 #define I40E_RX_DTYPE_SPLIT_ALWAYS  2
294 #define I40E_RX_SPLIT_L2      0x1
295 #define I40E_RX_SPLIT_IP      0x2
296 #define I40E_RX_SPLIT_TCP_UDP 0x4
297 #define I40E_RX_SPLIT_SCTP    0x8
298 
299 /* struct that defines a descriptor ring, associated with a VSI */
300 struct i40e_ring {
301 	struct i40e_ring *next;		/* pointer to next ring in q_vector */
302 	void *desc;			/* Descriptor ring memory */
303 	struct device *dev;		/* Used for DMA mapping */
304 	struct net_device *netdev;	/* netdev ring maps to */
305 	union {
306 		struct i40e_tx_buffer *tx_bi;
307 		struct i40e_rx_buffer *rx_bi;
308 	};
309 	unsigned long state;
310 	u16 queue_index;		/* Queue number of ring */
311 	u8 dcb_tc;			/* Traffic class of ring */
312 	u8 __iomem *tail;
313 
314 	/* high bit set means dynamic, use accessor routines to read/write.
315 	 * hardware only supports 2us resolution for the ITR registers.
316 	 * these values always store the USER setting, and must be converted
317 	 * before programming to a register.
318 	 */
319 	u16 rx_itr_setting;
320 	u16 tx_itr_setting;
321 
322 	u16 count;			/* Number of descriptors */
323 	u16 reg_idx;			/* HW register index of the ring */
324 	u16 rx_buf_len;
325 
326 	/* used in interrupt processing */
327 	u16 next_to_use;
328 	u16 next_to_clean;
329 
330 	u8 atr_sample_rate;
331 	u8 atr_count;
332 
333 	bool ring_active;		/* is ring online or not */
334 	bool arm_wb;		/* do something to arm write back */
335 	u8 packet_stride;
336 
337 	u16 flags;
338 #define I40E_TXR_FLAGS_WB_ON_ITR	BIT(0)
339 
340 	/* stats structs */
341 	struct i40e_queue_stats	stats;
342 	struct u64_stats_sync syncp;
343 	union {
344 		struct i40e_tx_queue_stats tx_stats;
345 		struct i40e_rx_queue_stats rx_stats;
346 	};
347 
348 	unsigned int size;		/* length of descriptor ring in bytes */
349 	dma_addr_t dma;			/* physical address of ring */
350 
351 	struct i40e_vsi *vsi;		/* Backreference to associated VSI */
352 	struct i40e_q_vector *q_vector;	/* Backreference to associated vector */
353 
354 	struct rcu_head rcu;		/* to avoid race on free */
355 	u16 next_to_alloc;
356 	struct sk_buff *skb;		/* When i40e_clean_rx_ring_irq() must
357 					 * return before it sees the EOP for
358 					 * the current packet, we save that skb
359 					 * here and resume receiving this
360 					 * packet the next time
361 					 * i40e_clean_rx_ring_irq() is called
362 					 * for this ring.
363 					 */
364 } ____cacheline_internodealigned_in_smp;
365 
366 enum i40e_latency_range {
367 	I40E_LOWEST_LATENCY = 0,
368 	I40E_LOW_LATENCY = 1,
369 	I40E_BULK_LATENCY = 2,
370 	I40E_ULTRA_LATENCY = 3,
371 };
372 
373 struct i40e_ring_container {
374 	/* array of pointers to rings */
375 	struct i40e_ring *ring;
376 	unsigned int total_bytes;	/* total bytes processed this int */
377 	unsigned int total_packets;	/* total packets processed this int */
378 	u16 count;
379 	enum i40e_latency_range latency_range;
380 	u16 itr;
381 };
382 
383 /* iterator for handling rings in ring container */
384 #define i40e_for_each_ring(pos, head) \
385 	for (pos = (head).ring; pos != NULL; pos = pos->next)
386 
387 bool i40e_alloc_rx_buffers(struct i40e_ring *rxr, u16 cleaned_count);
388 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
389 void i40e_clean_tx_ring(struct i40e_ring *tx_ring);
390 void i40e_clean_rx_ring(struct i40e_ring *rx_ring);
391 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring);
392 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring);
393 void i40e_free_tx_resources(struct i40e_ring *tx_ring);
394 void i40e_free_rx_resources(struct i40e_ring *rx_ring);
395 int i40e_napi_poll(struct napi_struct *napi, int budget);
396 #ifdef I40E_FCOE
397 void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
398 		 struct i40e_tx_buffer *first, u32 tx_flags,
399 		 const u8 hdr_len, u32 td_cmd, u32 td_offset);
400 int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
401 			       struct i40e_ring *tx_ring, u32 *flags);
402 #endif
403 void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector);
404 u32 i40e_get_tx_pending(struct i40e_ring *ring, bool in_sw);
405 int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size);
406 bool __i40e_chk_linearize(struct sk_buff *skb);
407 
408 /**
409  * i40e_get_head - Retrieve head from head writeback
410  * @tx_ring:  tx ring to fetch head of
411  *
412  * Returns value of Tx ring head based on value stored
413  * in head write-back location
414  **/
415 static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
416 {
417 	void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
418 
419 	return le32_to_cpu(*(volatile __le32 *)head);
420 }
421 
422 /**
423  * i40e_xmit_descriptor_count - calculate number of Tx descriptors needed
424  * @skb:     send buffer
425  * @tx_ring: ring to send buffer on
426  *
427  * Returns number of data descriptors needed for this skb. Returns 0 to indicate
428  * there is not enough descriptors available in this ring since we need at least
429  * one descriptor.
430  **/
431 static inline int i40e_xmit_descriptor_count(struct sk_buff *skb)
432 {
433 	const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
434 	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
435 	int count = 0, size = skb_headlen(skb);
436 
437 	for (;;) {
438 		count += i40e_txd_use_count(size);
439 
440 		if (!nr_frags--)
441 			break;
442 
443 		size = skb_frag_size(frag++);
444 	}
445 
446 	return count;
447 }
448 
449 /**
450  * i40e_maybe_stop_tx - 1st level check for Tx stop conditions
451  * @tx_ring: the ring to be checked
452  * @size:    the size buffer we want to assure is available
453  *
454  * Returns 0 if stop is not needed
455  **/
456 static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
457 {
458 	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
459 		return 0;
460 	return __i40e_maybe_stop_tx(tx_ring, size);
461 }
462 
463 /**
464  * i40e_chk_linearize - Check if there are more than 8 fragments per packet
465  * @skb:      send buffer
466  * @count:    number of buffers used
467  *
468  * Note: Our HW can't scatter-gather more than 8 fragments to build
469  * a packet on the wire and so we need to figure out the cases where we
470  * need to linearize the skb.
471  **/
472 static inline bool i40e_chk_linearize(struct sk_buff *skb, int count)
473 {
474 	/* Both TSO and single send will work if count is less than 8 */
475 	if (likely(count < I40E_MAX_BUFFER_TXD))
476 		return false;
477 
478 	if (skb_is_gso(skb))
479 		return __i40e_chk_linearize(skb);
480 
481 	/* we can support up to 8 data buffers for a single send */
482 	return count != I40E_MAX_BUFFER_TXD;
483 }
484 
485 /**
486  * i40e_rx_is_fcoe - returns true if the Rx packet type is FCoE
487  * @ptype: the packet type field from Rx descriptor write-back
488  **/
489 static inline bool i40e_rx_is_fcoe(u16 ptype)
490 {
491 	return (ptype >= I40E_RX_PTYPE_L2_FCOE_PAY3) &&
492 	       (ptype <= I40E_RX_PTYPE_L2_FCOE_VFT_FCOTHER);
493 }
494 
495 /**
496  * txring_txq - Find the netdev Tx ring based on the i40e Tx ring
497  * @ring: Tx ring to find the netdev equivalent of
498  **/
499 static inline struct netdev_queue *txring_txq(const struct i40e_ring *ring)
500 {
501 	return netdev_get_tx_queue(ring->netdev, ring->queue_index);
502 }
503 #endif /* _I40E_TXRX_H_ */
504