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  1/*******************************************************************************
  2 *
  3 * Intel Ethernet Controller XL710 Family Linux Virtual Function 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 */
 67enum 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 (a multiple of 128) */
106#define I40E_RXBUFFER_256   256
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_256 --> 960 byte skb (size-1024 slab)
118 * i.e. RXBUFFER_512 --> 1216 byte skb (size-2048 slab)
119 */
120#define I40E_RX_HDR_SIZE I40E_RXBUFFER_256
121#define i40e_rx_desc i40e_32byte_rx_desc
122
123/**
124 * i40e_test_staterr - tests bits in Rx descriptor status and error fields
125 * @rx_desc: pointer to receive descriptor (in le64 format)
126 * @stat_err_bits: value to mask
127 *
128 * This function does some fast chicanery in order to return the
129 * value of the mask which is really only used for boolean tests.
130 * The status_error_len doesn't need to be shifted because it begins
131 * at offset zero.
132 */
133static inline bool i40e_test_staterr(union i40e_rx_desc *rx_desc,
134				     const u64 stat_err_bits)
135{
136	return !!(rx_desc->wb.qword1.status_error_len &
137		  cpu_to_le64(stat_err_bits));
138}
139
140/* How many Rx Buffers do we bundle into one write to the hardware ? */
141#define I40E_RX_BUFFER_WRITE	16	/* Must be power of 2 */
142#define I40E_RX_INCREMENT(r, i) \
143	do {					\
144		(i)++;				\
145		if ((i) == (r)->count)		\
146			i = 0;			\
147		r->next_to_clean = i;		\
148	} while (0)
149
150#define I40E_RX_NEXT_DESC(r, i, n)		\
151	do {					\
152		(i)++;				\
153		if ((i) == (r)->count)		\
154			i = 0;			\
155		(n) = I40E_RX_DESC((r), (i));	\
156	} while (0)
157
158#define I40E_RX_NEXT_DESC_PREFETCH(r, i, n)		\
159	do {						\
160		I40E_RX_NEXT_DESC((r), (i), (n));	\
161		prefetch((n));				\
162	} while (0)
163
164#define I40E_MAX_BUFFER_TXD	8
165#define I40E_MIN_TX_LEN		17
166
167/* The size limit for a transmit buffer in a descriptor is (16K - 1).
168 * In order to align with the read requests we will align the value to
169 * the nearest 4K which represents our maximum read request size.
170 */
171#define I40E_MAX_READ_REQ_SIZE		4096
172#define I40E_MAX_DATA_PER_TXD		(16 * 1024 - 1)
173#define I40E_MAX_DATA_PER_TXD_ALIGNED \
174	(I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1))
175
176/**
177 * i40e_txd_use_count  - estimate the number of descriptors needed for Tx
178 * @size: transmit request size in bytes
179 *
180 * Due to hardware alignment restrictions (4K alignment), we need to
181 * assume that we can have no more than 12K of data per descriptor, even
182 * though each descriptor can take up to 16K - 1 bytes of aligned memory.
183 * Thus, we need to divide by 12K. But division is slow! Instead,
184 * we decompose the operation into shifts and one relatively cheap
185 * multiply operation.
186 *
187 * To divide by 12K, we first divide by 4K, then divide by 3:
188 *     To divide by 4K, shift right by 12 bits
189 *     To divide by 3, multiply by 85, then divide by 256
190 *     (Divide by 256 is done by shifting right by 8 bits)
191 * Finally, we add one to round up. Because 256 isn't an exact multiple of
192 * 3, we'll underestimate near each multiple of 12K. This is actually more
193 * accurate as we have 4K - 1 of wiggle room that we can fit into the last
194 * segment.  For our purposes this is accurate out to 1M which is orders of
195 * magnitude greater than our largest possible GSO size.
196 *
197 * This would then be implemented as:
198 *     return (((size >> 12) * 85) >> 8) + 1;
199 *
200 * Since multiplication and division are commutative, we can reorder
201 * operations into:
202 *     return ((size * 85) >> 20) + 1;
203 */
204static inline unsigned int i40e_txd_use_count(unsigned int size)
205{
206	return ((size * 85) >> 20) + 1;
207}
208
209/* Tx Descriptors needed, worst case */
210#define DESC_NEEDED (MAX_SKB_FRAGS + 4)
211#define I40E_MIN_DESC_PENDING	4
212
213#define I40E_TX_FLAGS_HW_VLAN		BIT(1)
214#define I40E_TX_FLAGS_SW_VLAN		BIT(2)
215#define I40E_TX_FLAGS_TSO		BIT(3)
216#define I40E_TX_FLAGS_IPV4		BIT(4)
217#define I40E_TX_FLAGS_IPV6		BIT(5)
218#define I40E_TX_FLAGS_FCCRC		BIT(6)
219#define I40E_TX_FLAGS_FSO		BIT(7)
220#define I40E_TX_FLAGS_FD_SB		BIT(9)
221#define I40E_TX_FLAGS_VXLAN_TUNNEL	BIT(10)
222#define I40E_TX_FLAGS_VLAN_MASK		0xffff0000
223#define I40E_TX_FLAGS_VLAN_PRIO_MASK	0xe0000000
224#define I40E_TX_FLAGS_VLAN_PRIO_SHIFT	29
225#define I40E_TX_FLAGS_VLAN_SHIFT	16
226
227struct i40e_tx_buffer {
228	struct i40e_tx_desc *next_to_watch;
229	union {
230		struct sk_buff *skb;
231		void *raw_buf;
232	};
233	unsigned int bytecount;
234	unsigned short gso_segs;
235
236	DEFINE_DMA_UNMAP_ADDR(dma);
237	DEFINE_DMA_UNMAP_LEN(len);
238	u32 tx_flags;
239};
240
241struct i40e_rx_buffer {
242	struct sk_buff *skb;
243	dma_addr_t dma;
244	struct page *page;
245	unsigned int page_offset;
246};
247
248struct i40e_queue_stats {
249	u64 packets;
250	u64 bytes;
251};
252
253struct i40e_tx_queue_stats {
254	u64 restart_queue;
255	u64 tx_busy;
256	u64 tx_done_old;
257	u64 tx_linearize;
258	u64 tx_force_wb;
259	u64 tx_lost_interrupt;
260};
261
262struct i40e_rx_queue_stats {
263	u64 non_eop_descs;
264	u64 alloc_page_failed;
265	u64 alloc_buff_failed;
266	u64 page_reuse_count;
267	u64 realloc_count;
268};
269
270enum i40e_ring_state_t {
271	__I40E_TX_FDIR_INIT_DONE,
272	__I40E_TX_XPS_INIT_DONE,
273};
274
275/* some useful defines for virtchannel interface, which
276 * is the only remaining user of header split
277 */
278#define I40E_RX_DTYPE_NO_SPLIT      0
279#define I40E_RX_DTYPE_HEADER_SPLIT  1
280#define I40E_RX_DTYPE_SPLIT_ALWAYS  2
281#define I40E_RX_SPLIT_L2      0x1
282#define I40E_RX_SPLIT_IP      0x2
283#define I40E_RX_SPLIT_TCP_UDP 0x4
284#define I40E_RX_SPLIT_SCTP    0x8
285
286/* struct that defines a descriptor ring, associated with a VSI */
287struct i40e_ring {
288	struct i40e_ring *next;		/* pointer to next ring in q_vector */
289	void *desc;			/* Descriptor ring memory */
290	struct device *dev;		/* Used for DMA mapping */
291	struct net_device *netdev;	/* netdev ring maps to */
292	union {
293		struct i40e_tx_buffer *tx_bi;
294		struct i40e_rx_buffer *rx_bi;
295	};
296	unsigned long state;
297	u16 queue_index;		/* Queue number of ring */
298	u8 dcb_tc;			/* Traffic class of ring */
299	u8 __iomem *tail;
300
301	/* high bit set means dynamic, use accessors routines to read/write.
302	 * hardware only supports 2us resolution for the ITR registers.
303	 * these values always store the USER setting, and must be converted
304	 * before programming to a register.
305	 */
306	u16 rx_itr_setting;
307	u16 tx_itr_setting;
308
309	u16 count;			/* Number of descriptors */
310	u16 reg_idx;			/* HW register index of the ring */
311	u16 rx_buf_len;
312
313	/* used in interrupt processing */
314	u16 next_to_use;
315	u16 next_to_clean;
316
317	u8 atr_sample_rate;
318	u8 atr_count;
319
320	bool ring_active;		/* is ring online or not */
321	bool arm_wb;		/* do something to arm write back */
322	u8 packet_stride;
323
324	u16 flags;
325#define I40E_TXR_FLAGS_WB_ON_ITR	BIT(0)
326
327	/* stats structs */
328	struct i40e_queue_stats	stats;
329	struct u64_stats_sync syncp;
330	union {
331		struct i40e_tx_queue_stats tx_stats;
332		struct i40e_rx_queue_stats rx_stats;
333	};
334
335	unsigned int size;		/* length of descriptor ring in bytes */
336	dma_addr_t dma;			/* physical address of ring */
337
338	struct i40e_vsi *vsi;		/* Backreference to associated VSI */
339	struct i40e_q_vector *q_vector;	/* Backreference to associated vector */
340
341	struct rcu_head rcu;		/* to avoid race on free */
342	u16 next_to_alloc;
343} ____cacheline_internodealigned_in_smp;
344
345enum i40e_latency_range {
346	I40E_LOWEST_LATENCY = 0,
347	I40E_LOW_LATENCY = 1,
348	I40E_BULK_LATENCY = 2,
349	I40E_ULTRA_LATENCY = 3,
350};
351
352struct i40e_ring_container {
353	/* array of pointers to rings */
354	struct i40e_ring *ring;
355	unsigned int total_bytes;	/* total bytes processed this int */
356	unsigned int total_packets;	/* total packets processed this int */
357	u16 count;
358	enum i40e_latency_range latency_range;
359	u16 itr;
360};
361
362/* iterator for handling rings in ring container */
363#define i40e_for_each_ring(pos, head) \
364	for (pos = (head).ring; pos != NULL; pos = pos->next)
365
366bool i40evf_alloc_rx_buffers(struct i40e_ring *rxr, u16 cleaned_count);
367netdev_tx_t i40evf_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
368void i40evf_clean_tx_ring(struct i40e_ring *tx_ring);
369void i40evf_clean_rx_ring(struct i40e_ring *rx_ring);
370int i40evf_setup_tx_descriptors(struct i40e_ring *tx_ring);
371int i40evf_setup_rx_descriptors(struct i40e_ring *rx_ring);
372void i40evf_free_tx_resources(struct i40e_ring *tx_ring);
373void i40evf_free_rx_resources(struct i40e_ring *rx_ring);
374int i40evf_napi_poll(struct napi_struct *napi, int budget);
375void i40evf_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector);
376u32 i40evf_get_tx_pending(struct i40e_ring *ring, bool in_sw);
377int __i40evf_maybe_stop_tx(struct i40e_ring *tx_ring, int size);
378bool __i40evf_chk_linearize(struct sk_buff *skb);
379
380/**
381 * i40e_get_head - Retrieve head from head writeback
382 * @tx_ring: Tx ring to fetch head of
383 *
384 * Returns value of Tx ring head based on value stored
385 * in head write-back location
386 **/
387static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
388{
389	void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
390
391	return le32_to_cpu(*(volatile __le32 *)head);
392}
393
394/**
395 * i40e_xmit_descriptor_count - calculate number of Tx descriptors needed
396 * @skb:     send buffer
397 * @tx_ring: ring to send buffer on
398 *
399 * Returns number of data descriptors needed for this skb. Returns 0 to indicate
400 * there is not enough descriptors available in this ring since we need at least
401 * one descriptor.
402 **/
403static inline int i40e_xmit_descriptor_count(struct sk_buff *skb)
404{
405	const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
406	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
407	int count = 0, size = skb_headlen(skb);
408
409	for (;;) {
410		count += i40e_txd_use_count(size);
411
412		if (!nr_frags--)
413			break;
414
415		size = skb_frag_size(frag++);
416	}
417
418	return count;
419}
420
421/**
422 * i40e_maybe_stop_tx - 1st level check for Tx stop conditions
423 * @tx_ring: the ring to be checked
424 * @size:    the size buffer we want to assure is available
425 *
426 * Returns 0 if stop is not needed
427 **/
428static inline int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
429{
430	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
431		return 0;
432	return __i40evf_maybe_stop_tx(tx_ring, size);
433}
434
435/**
436 * i40e_chk_linearize - Check if there are more than 8 fragments per packet
437 * @skb:      send buffer
438 * @count:    number of buffers used
439 *
440 * Note: Our HW can't scatter-gather more than 8 fragments to build
441 * a packet on the wire and so we need to figure out the cases where we
442 * need to linearize the skb.
443 **/
444static inline bool i40e_chk_linearize(struct sk_buff *skb, int count)
445{
446	/* Both TSO and single send will work if count is less than 8 */
447	if (likely(count < I40E_MAX_BUFFER_TXD))
448		return false;
449
450	if (skb_is_gso(skb))
451		return __i40evf_chk_linearize(skb);
452
453	/* we can support up to 8 data buffers for a single send */
454	return count != I40E_MAX_BUFFER_TXD;
455}
456
457/**
458 * i40e_rx_is_fcoe - returns true if the Rx packet type is FCoE
459 * @ptype: the packet type field from Rx descriptor write-back
460 **/
461static inline bool i40e_rx_is_fcoe(u16 ptype)
462{
463	return (ptype >= I40E_RX_PTYPE_L2_FCOE_PAY3) &&
464	       (ptype <= I40E_RX_PTYPE_L2_FCOE_VFT_FCOTHER);
465}
466
467/**
468 * txring_txq - Find the netdev Tx ring based on the i40e Tx ring
469 * @ring: Tx ring to find the netdev equivalent of
470 **/
471static inline struct netdev_queue *txring_txq(const struct i40e_ring *ring)
472{
473	return netdev_get_tx_queue(ring->netdev, ring->queue_index);
474}
475#endif /* _I40E_TXRX_H_ */