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 #define INTRL_USEC_TO_REG(set) ((set) ? ((set) >> 2) | INTRL_ENA : 0)
56 #define I40E_INTRL_8K              125     /* 8000 ints/sec */
57 #define I40E_INTRL_62K             16      /* 62500 ints/sec */
58 #define I40E_INTRL_83K             12      /* 83333 ints/sec */
59 
60 #define I40E_QUEUE_END_OF_LIST 0x7FF
61 
62 /* this enum matches hardware bits and is meant to be used by DYN_CTLN
63  * registers and QINT registers or more generally anywhere in the manual
64  * mentioning ITR_INDX, ITR_NONE cannot be used as an index 'n' into any
65  * register but instead is a special value meaning "don't update" ITR0/1/2.
66  */
67 enum i40e_dyn_idx_t {
68 	I40E_IDX_ITR0 = 0,
69 	I40E_IDX_ITR1 = 1,
70 	I40E_IDX_ITR2 = 2,
71 	I40E_ITR_NONE = 3	/* ITR_NONE must not be used as an index */
72 };
73 
74 /* these are indexes into ITRN registers */
75 #define I40E_RX_ITR    I40E_IDX_ITR0
76 #define I40E_TX_ITR    I40E_IDX_ITR1
77 #define I40E_PE_ITR    I40E_IDX_ITR2
78 
79 /* Supported RSS offloads */
80 #define I40E_DEFAULT_RSS_HENA ( \
81 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_UDP) | \
82 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_SCTP) | \
83 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP) | \
84 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_OTHER) | \
85 	BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV4) | \
86 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_UDP) | \
87 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP) | \
88 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_SCTP) | \
89 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_OTHER) | \
90 	BIT_ULL(I40E_FILTER_PCTYPE_FRAG_IPV6) | \
91 	BIT_ULL(I40E_FILTER_PCTYPE_L2_PAYLOAD))
92 
93 #define I40E_DEFAULT_RSS_HENA_EXPANDED (I40E_DEFAULT_RSS_HENA | \
94 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV4_TCP_SYN_NO_ACK) | \
95 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV4_UDP) | \
96 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV4_UDP) | \
97 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_IPV6_TCP_SYN_NO_ACK) | \
98 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_UNICAST_IPV6_UDP) | \
99 	BIT_ULL(I40E_FILTER_PCTYPE_NONF_MULTICAST_IPV6_UDP))
100 
101 #define i40e_pf_get_default_rss_hena(pf) \
102 	(((pf)->flags & I40E_FLAG_MULTIPLE_TCP_UDP_RSS_PCTYPE) ? \
103 	  I40E_DEFAULT_RSS_HENA_EXPANDED : I40E_DEFAULT_RSS_HENA)
104 
105 /* Supported Rx Buffer Sizes */
106 #define I40E_RXBUFFER_512   512    /* Used for packet split */
107 #define I40E_RXBUFFER_2048  2048
108 #define I40E_RXBUFFER_3072  3072   /* For FCoE MTU of 2158 */
109 #define I40E_RXBUFFER_4096  4096
110 #define I40E_RXBUFFER_8192  8192
111 #define I40E_MAX_RXBUFFER   9728  /* largest size for single descriptor */
112 
113 /* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we
114  * reserve 2 more, and skb_shared_info adds an additional 384 bytes more,
115  * this adds up to 512 bytes of extra data meaning the smallest allocation
116  * we could have is 1K.
117  * i.e. RXBUFFER_512 --> size-1024 slab
118  */
119 #define I40E_RX_HDR_SIZE  I40E_RXBUFFER_512
120 
121 /* How many Rx Buffers do we bundle into one write to the hardware ? */
122 #define I40E_RX_BUFFER_WRITE	16	/* Must be power of 2 */
123 #define I40E_RX_INCREMENT(r, i) \
124 	do {					\
125 		(i)++;				\
126 		if ((i) == (r)->count)		\
127 			i = 0;			\
128 		r->next_to_clean = i;		\
129 	} while (0)
130 
131 #define I40E_RX_NEXT_DESC(r, i, n)		\
132 	do {					\
133 		(i)++;				\
134 		if ((i) == (r)->count)		\
135 			i = 0;			\
136 		(n) = I40E_RX_DESC((r), (i));	\
137 	} while (0)
138 
139 #define I40E_RX_NEXT_DESC_PREFETCH(r, i, n)		\
140 	do {						\
141 		I40E_RX_NEXT_DESC((r), (i), (n));	\
142 		prefetch((n));				\
143 	} while (0)
144 
145 #define i40e_rx_desc i40e_32byte_rx_desc
146 
147 #define I40E_MAX_BUFFER_TXD	8
148 #define I40E_MIN_TX_LEN		17
149 #define I40E_MAX_DATA_PER_TXD	8192
150 
151 /* Tx Descriptors needed, worst case */
152 #define TXD_USE_COUNT(S) DIV_ROUND_UP((S), I40E_MAX_DATA_PER_TXD)
153 #define DESC_NEEDED (MAX_SKB_FRAGS + 4)
154 #define I40E_MIN_DESC_PENDING	4
155 
156 #define I40E_TX_FLAGS_HW_VLAN		BIT(1)
157 #define I40E_TX_FLAGS_SW_VLAN		BIT(2)
158 #define I40E_TX_FLAGS_TSO		BIT(3)
159 #define I40E_TX_FLAGS_IPV4		BIT(4)
160 #define I40E_TX_FLAGS_IPV6		BIT(5)
161 #define I40E_TX_FLAGS_FCCRC		BIT(6)
162 #define I40E_TX_FLAGS_FSO		BIT(7)
163 #define I40E_TX_FLAGS_TSYN		BIT(8)
164 #define I40E_TX_FLAGS_FD_SB		BIT(9)
165 #define I40E_TX_FLAGS_UDP_TUNNEL	BIT(10)
166 #define I40E_TX_FLAGS_VLAN_MASK		0xffff0000
167 #define I40E_TX_FLAGS_VLAN_PRIO_MASK	0xe0000000
168 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT	29
169 #define I40E_TX_FLAGS_VLAN_SHIFT	16
170 
171 struct i40e_tx_buffer {
172 	struct i40e_tx_desc *next_to_watch;
173 	union {
174 		struct sk_buff *skb;
175 		void *raw_buf;
176 	};
177 	unsigned int bytecount;
178 	unsigned short gso_segs;
179 
180 	DEFINE_DMA_UNMAP_ADDR(dma);
181 	DEFINE_DMA_UNMAP_LEN(len);
182 	u32 tx_flags;
183 };
184 
185 struct i40e_rx_buffer {
186 	struct sk_buff *skb;
187 	void *hdr_buf;
188 	dma_addr_t dma;
189 	struct page *page;
190 	dma_addr_t page_dma;
191 	unsigned int page_offset;
192 };
193 
194 struct i40e_queue_stats {
195 	u64 packets;
196 	u64 bytes;
197 };
198 
199 struct i40e_tx_queue_stats {
200 	u64 restart_queue;
201 	u64 tx_busy;
202 	u64 tx_done_old;
203 	u64 tx_linearize;
204 	u64 tx_force_wb;
205 	u64 tx_lost_interrupt;
206 };
207 
208 struct i40e_rx_queue_stats {
209 	u64 non_eop_descs;
210 	u64 alloc_page_failed;
211 	u64 alloc_buff_failed;
212 	u64 page_reuse_count;
213 	u64 realloc_count;
214 };
215 
216 enum i40e_ring_state_t {
217 	__I40E_TX_FDIR_INIT_DONE,
218 	__I40E_TX_XPS_INIT_DONE,
219 	__I40E_RX_PS_ENABLED,
220 	__I40E_RX_16BYTE_DESC_ENABLED,
221 };
222 
223 #define ring_is_ps_enabled(ring) \
224 	test_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
225 #define set_ring_ps_enabled(ring) \
226 	set_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
227 #define clear_ring_ps_enabled(ring) \
228 	clear_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
229 #define ring_is_16byte_desc_enabled(ring) \
230 	test_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
231 #define set_ring_16byte_desc_enabled(ring) \
232 	set_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
233 #define clear_ring_16byte_desc_enabled(ring) \
234 	clear_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
235 
236 /* struct that defines a descriptor ring, associated with a VSI */
237 struct i40e_ring {
238 	struct i40e_ring *next;		/* pointer to next ring in q_vector */
239 	void *desc;			/* Descriptor ring memory */
240 	struct device *dev;		/* Used for DMA mapping */
241 	struct net_device *netdev;	/* netdev ring maps to */
242 	union {
243 		struct i40e_tx_buffer *tx_bi;
244 		struct i40e_rx_buffer *rx_bi;
245 	};
246 	unsigned long state;
247 	u16 queue_index;		/* Queue number of ring */
248 	u8 dcb_tc;			/* Traffic class of ring */
249 	u8 __iomem *tail;
250 
251 	/* high bit set means dynamic, use accessor routines to read/write.
252 	 * hardware only supports 2us resolution for the ITR registers.
253 	 * these values always store the USER setting, and must be converted
254 	 * before programming to a register.
255 	 */
256 	u16 rx_itr_setting;
257 	u16 tx_itr_setting;
258 
259 	u16 count;			/* Number of descriptors */
260 	u16 reg_idx;			/* HW register index of the ring */
261 	u16 rx_hdr_len;
262 	u16 rx_buf_len;
263 	u8  dtype;
264 #define I40E_RX_DTYPE_NO_SPLIT      0
265 #define I40E_RX_DTYPE_HEADER_SPLIT  1
266 #define I40E_RX_DTYPE_SPLIT_ALWAYS  2
267 #define I40E_RX_SPLIT_L2      0x1
268 #define I40E_RX_SPLIT_IP      0x2
269 #define I40E_RX_SPLIT_TCP_UDP 0x4
270 #define I40E_RX_SPLIT_SCTP    0x8
271 
272 	/* used in interrupt processing */
273 	u16 next_to_use;
274 	u16 next_to_clean;
275 
276 	u8 atr_sample_rate;
277 	u8 atr_count;
278 
279 	unsigned long last_rx_timestamp;
280 
281 	bool ring_active;		/* is ring online or not */
282 	bool arm_wb;		/* do something to arm write back */
283 	u8 packet_stride;
284 
285 	u16 flags;
286 #define I40E_TXR_FLAGS_WB_ON_ITR	BIT(0)
287 #define I40E_TXR_FLAGS_LAST_XMIT_MORE_SET BIT(2)
288 
289 	/* stats structs */
290 	struct i40e_queue_stats	stats;
291 	struct u64_stats_sync syncp;
292 	union {
293 		struct i40e_tx_queue_stats tx_stats;
294 		struct i40e_rx_queue_stats rx_stats;
295 	};
296 
297 	unsigned int size;		/* length of descriptor ring in bytes */
298 	dma_addr_t dma;			/* physical address of ring */
299 
300 	struct i40e_vsi *vsi;		/* Backreference to associated VSI */
301 	struct i40e_q_vector *q_vector;	/* Backreference to associated vector */
302 
303 	struct rcu_head rcu;		/* to avoid race on free */
304 } ____cacheline_internodealigned_in_smp;
305 
306 enum i40e_latency_range {
307 	I40E_LOWEST_LATENCY = 0,
308 	I40E_LOW_LATENCY = 1,
309 	I40E_BULK_LATENCY = 2,
310 	I40E_ULTRA_LATENCY = 3,
311 };
312 
313 struct i40e_ring_container {
314 	/* array of pointers to rings */
315 	struct i40e_ring *ring;
316 	unsigned int total_bytes;	/* total bytes processed this int */
317 	unsigned int total_packets;	/* total packets processed this int */
318 	u16 count;
319 	enum i40e_latency_range latency_range;
320 	u16 itr;
321 };
322 
323 /* iterator for handling rings in ring container */
324 #define i40e_for_each_ring(pos, head) \
325 	for (pos = (head).ring; pos != NULL; pos = pos->next)
326 
327 bool i40e_alloc_rx_buffers_ps(struct i40e_ring *rxr, u16 cleaned_count);
328 bool i40e_alloc_rx_buffers_1buf(struct i40e_ring *rxr, u16 cleaned_count);
329 void i40e_alloc_rx_headers(struct i40e_ring *rxr);
330 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
331 void i40e_clean_tx_ring(struct i40e_ring *tx_ring);
332 void i40e_clean_rx_ring(struct i40e_ring *rx_ring);
333 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring);
334 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring);
335 void i40e_free_tx_resources(struct i40e_ring *tx_ring);
336 void i40e_free_rx_resources(struct i40e_ring *rx_ring);
337 int i40e_napi_poll(struct napi_struct *napi, int budget);
338 #ifdef I40E_FCOE
339 void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
340 		 struct i40e_tx_buffer *first, u32 tx_flags,
341 		 const u8 hdr_len, u32 td_cmd, u32 td_offset);
342 int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
343 			       struct i40e_ring *tx_ring, u32 *flags);
344 #endif
345 void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector);
346 u32 i40e_get_tx_pending(struct i40e_ring *ring, bool in_sw);
347 int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size);
348 bool __i40e_chk_linearize(struct sk_buff *skb);
349 
350 /**
351  * i40e_get_head - Retrieve head from head writeback
352  * @tx_ring:  tx ring to fetch head of
353  *
354  * Returns value of Tx ring head based on value stored
355  * in head write-back location
356  **/
357 static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
358 {
359 	void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
360 
361 	return le32_to_cpu(*(volatile __le32 *)head);
362 }
363 
364 /**
365  * i40e_xmit_descriptor_count - calculate number of Tx descriptors needed
366  * @skb:     send buffer
367  * @tx_ring: ring to send buffer on
368  *
369  * Returns number of data descriptors needed for this skb. Returns 0 to indicate
370  * there is not enough descriptors available in this ring since we need at least
371  * one descriptor.
372  **/
373 static inline int i40e_xmit_descriptor_count(struct sk_buff *skb)
374 {
375 	const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
376 	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
377 	int count = 0, size = skb_headlen(skb);
378 
379 	for (;;) {
380 		count += TXD_USE_COUNT(size);
381 
382 		if (!nr_frags--)
383 			break;
384 
385 		size = skb_frag_size(frag++);
386 	}
387 
388 	return count;
389 }
390 
391 /**
392  * i40e_maybe_stop_tx - 1st level check for Tx stop conditions
393  * @tx_ring: the ring to be checked
394  * @size:    the size buffer we want to assure is available
395  *
396  * Returns 0 if stop is not needed
397  **/
398 static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
399 {
400 	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
401 		return 0;
402 	return __i40e_maybe_stop_tx(tx_ring, size);
403 }
404 
405 /**
406  * i40e_chk_linearize - Check if there are more than 8 fragments per packet
407  * @skb:      send buffer
408  * @count:    number of buffers used
409  *
410  * Note: Our HW can't scatter-gather more than 8 fragments to build
411  * a packet on the wire and so we need to figure out the cases where we
412  * need to linearize the skb.
413  **/
414 static inline bool i40e_chk_linearize(struct sk_buff *skb, int count)
415 {
416 	/* we can only support up to 8 data buffers for a single send */
417 	if (likely(count <= I40E_MAX_BUFFER_TXD))
418 		return false;
419 
420 	return __i40e_chk_linearize(skb);
421 }
422 #endif /* _I40E_TXRX_H_ */
423