1 /*******************************************************************************
2  *
3  * Intel Ethernet Controller XL710 Family Linux Driver
4  * Copyright(c) 2013 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 with
16  * this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * The full GNU General Public License is included in this distribution in
20  * the file called "COPYING".
21  *
22  * Contact Information:
23  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
24  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
25  *
26  ******************************************************************************/
27 
28 /* Interrupt Throttling and Rate Limiting (storm control) Goodies */
29 
30 #define I40E_MAX_ITR               0x07FF
31 #define I40E_MIN_ITR               0x0001
32 #define I40E_ITR_USEC_RESOLUTION   2
33 #define I40E_MAX_IRATE             0x03F
34 #define I40E_MIN_IRATE             0x001
35 #define I40E_IRATE_USEC_RESOLUTION 4
36 #define I40E_ITR_100K              0x0005
37 #define I40E_ITR_20K               0x0019
38 #define I40E_ITR_8K                0x003E
39 #define I40E_ITR_4K                0x007A
40 #define I40E_ITR_RX_DEF            I40E_ITR_8K
41 #define I40E_ITR_TX_DEF            I40E_ITR_4K
42 #define I40E_ITR_DYNAMIC           0x8000  /* use top bit as a flag */
43 #define I40E_MIN_INT_RATE          250     /* ~= 1000000 / (I40E_MAX_ITR * 2) */
44 #define I40E_MAX_INT_RATE          500000  /* == 1000000 / (I40E_MIN_ITR * 2) */
45 #define I40E_DEFAULT_IRQ_WORK      256
46 #define ITR_TO_REG(setting) ((setting & ~I40E_ITR_DYNAMIC) >> 1)
47 #define ITR_IS_DYNAMIC(setting) (!!(setting & I40E_ITR_DYNAMIC))
48 #define ITR_REG_TO_USEC(itr_reg) (itr_reg << 1)
49 
50 #define I40E_QUEUE_END_OF_LIST 0x7FF
51 
52 #define I40E_ITR_NONE  3
53 #define I40E_RX_ITR    0
54 #define I40E_TX_ITR    1
55 #define I40E_PE_ITR    2
56 /* Supported Rx Buffer Sizes */
57 #define I40E_RXBUFFER_512   512    /* Used for packet split */
58 #define I40E_RXBUFFER_2048  2048
59 #define I40E_RXBUFFER_3072  3072   /* For FCoE MTU of 2158 */
60 #define I40E_RXBUFFER_4096  4096
61 #define I40E_RXBUFFER_8192  8192
62 #define I40E_MAX_RXBUFFER   9728  /* largest size for single descriptor */
63 
64 /* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we
65  * reserve 2 more, and skb_shared_info adds an additional 384 bytes more,
66  * this adds up to 512 bytes of extra data meaning the smallest allocation
67  * we could have is 1K.
68  * i.e. RXBUFFER_512 --> size-1024 slab
69  */
70 #define I40E_RX_HDR_SIZE  I40E_RXBUFFER_512
71 
72 /* How many Rx Buffers do we bundle into one write to the hardware ? */
73 #define I40E_RX_BUFFER_WRITE	16	/* Must be power of 2 */
74 #define I40E_RX_NEXT_DESC(r, i, n)		\
75 	do {					\
76 		(i)++;				\
77 		if ((i) == (r)->count)		\
78 			i = 0;			\
79 		(n) = I40E_RX_DESC((r), (i));	\
80 	} while (0)
81 
82 #define I40E_RX_NEXT_DESC_PREFETCH(r, i, n)		\
83 	do {						\
84 		I40E_RX_NEXT_DESC((r), (i), (n));	\
85 		prefetch((n));				\
86 	} while (0)
87 
88 #define i40e_rx_desc i40e_32byte_rx_desc
89 
90 #define I40E_MIN_TX_LEN		17
91 #define I40E_MAX_DATA_PER_TXD	16383	/* aka 16kB - 1 */
92 
93 /* Tx Descriptors needed, worst case */
94 #define TXD_USE_COUNT(S) DIV_ROUND_UP((S), I40E_MAX_DATA_PER_TXD)
95 #define DESC_NEEDED ((MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE)) + 4)
96 
97 #define I40E_TX_FLAGS_CSUM		(u32)(1)
98 #define I40E_TX_FLAGS_HW_VLAN		(u32)(1 << 1)
99 #define I40E_TX_FLAGS_SW_VLAN		(u32)(1 << 2)
100 #define I40E_TX_FLAGS_TSO		(u32)(1 << 3)
101 #define I40E_TX_FLAGS_IPV4		(u32)(1 << 4)
102 #define I40E_TX_FLAGS_IPV6		(u32)(1 << 5)
103 #define I40E_TX_FLAGS_FCCRC		(u32)(1 << 6)
104 #define I40E_TX_FLAGS_FSO		(u32)(1 << 7)
105 #define I40E_TX_FLAGS_TXSW		(u32)(1 << 8)
106 #define I40E_TX_FLAGS_MAPPED_AS_PAGE	(u32)(1 << 9)
107 #define I40E_TX_FLAGS_VLAN_MASK		0xffff0000
108 #define I40E_TX_FLAGS_VLAN_PRIO_MASK	0xe0000000
109 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT	29
110 #define I40E_TX_FLAGS_VLAN_SHIFT	16
111 
112 struct i40e_tx_buffer {
113 	struct sk_buff *skb;
114 	dma_addr_t dma;
115 	unsigned long time_stamp;
116 	u16 length;
117 	u32 tx_flags;
118 	struct i40e_tx_desc *next_to_watch;
119 	unsigned int bytecount;
120 	u16 gso_segs;
121 	u8 mapped_as_page;
122 };
123 
124 struct i40e_rx_buffer {
125 	struct sk_buff *skb;
126 	dma_addr_t dma;
127 	struct page *page;
128 	dma_addr_t page_dma;
129 	unsigned int page_offset;
130 };
131 
132 struct i40e_tx_queue_stats {
133 	u64 packets;
134 	u64 bytes;
135 	u64 restart_queue;
136 	u64 tx_busy;
137 	u64 completed;
138 	u64 tx_done_old;
139 };
140 
141 struct i40e_rx_queue_stats {
142 	u64 packets;
143 	u64 bytes;
144 	u64 non_eop_descs;
145 	u64 alloc_rx_page_failed;
146 	u64 alloc_rx_buff_failed;
147 };
148 
149 enum i40e_ring_state_t {
150 	__I40E_TX_FDIR_INIT_DONE,
151 	__I40E_TX_XPS_INIT_DONE,
152 	__I40E_TX_DETECT_HANG,
153 	__I40E_HANG_CHECK_ARMED,
154 	__I40E_RX_PS_ENABLED,
155 	__I40E_RX_LRO_ENABLED,
156 	__I40E_RX_16BYTE_DESC_ENABLED,
157 };
158 
159 #define ring_is_ps_enabled(ring) \
160 	test_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
161 #define set_ring_ps_enabled(ring) \
162 	set_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
163 #define clear_ring_ps_enabled(ring) \
164 	clear_bit(__I40E_RX_PS_ENABLED, &(ring)->state)
165 #define check_for_tx_hang(ring) \
166 	test_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
167 #define set_check_for_tx_hang(ring) \
168 	set_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
169 #define clear_check_for_tx_hang(ring) \
170 	clear_bit(__I40E_TX_DETECT_HANG, &(ring)->state)
171 #define ring_is_lro_enabled(ring) \
172 	test_bit(__I40E_RX_LRO_ENABLED, &(ring)->state)
173 #define set_ring_lro_enabled(ring) \
174 	set_bit(__I40E_RX_LRO_ENABLED, &(ring)->state)
175 #define clear_ring_lro_enabled(ring) \
176 	clear_bit(__I40E_RX_LRO_ENABLED, &(ring)->state)
177 #define ring_is_16byte_desc_enabled(ring) \
178 	test_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
179 #define set_ring_16byte_desc_enabled(ring) \
180 	set_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
181 #define clear_ring_16byte_desc_enabled(ring) \
182 	clear_bit(__I40E_RX_16BYTE_DESC_ENABLED, &(ring)->state)
183 
184 /* struct that defines a descriptor ring, associated with a VSI */
185 struct i40e_ring {
186 	void *desc;			/* Descriptor ring memory */
187 	struct device *dev;		/* Used for DMA mapping */
188 	struct net_device *netdev;	/* netdev ring maps to */
189 	union {
190 		struct i40e_tx_buffer *tx_bi;
191 		struct i40e_rx_buffer *rx_bi;
192 	};
193 	unsigned long state;
194 	u16 queue_index;		/* Queue number of ring */
195 	u8 dcb_tc;			/* Traffic class of ring */
196 	u8 __iomem *tail;
197 
198 	u16 count;			/* Number of descriptors */
199 	u16 reg_idx;			/* HW register index of the ring */
200 	u16 rx_hdr_len;
201 	u16 rx_buf_len;
202 	u8  dtype;
203 #define I40E_RX_DTYPE_NO_SPLIT      0
204 #define I40E_RX_DTYPE_SPLIT_ALWAYS  1
205 #define I40E_RX_DTYPE_HEADER_SPLIT  2
206 	u8  hsplit;
207 #define I40E_RX_SPLIT_L2      0x1
208 #define I40E_RX_SPLIT_IP      0x2
209 #define I40E_RX_SPLIT_TCP_UDP 0x4
210 #define I40E_RX_SPLIT_SCTP    0x8
211 
212 	/* used in interrupt processing */
213 	u16 next_to_use;
214 	u16 next_to_clean;
215 
216 	u8 atr_sample_rate;
217 	u8 atr_count;
218 
219 	bool ring_active;		/* is ring online or not */
220 
221 	/* stats structs */
222 	union {
223 		struct i40e_tx_queue_stats tx_stats;
224 		struct i40e_rx_queue_stats rx_stats;
225 	};
226 
227 	unsigned int size;		/* length of descriptor ring in bytes */
228 	dma_addr_t dma;			/* physical address of ring */
229 
230 	struct i40e_vsi *vsi;		/* Backreference to associated VSI */
231 	struct i40e_q_vector *q_vector;	/* Backreference to associated vector */
232 } ____cacheline_internodealigned_in_smp;
233 
234 enum i40e_latency_range {
235 	I40E_LOWEST_LATENCY = 0,
236 	I40E_LOW_LATENCY = 1,
237 	I40E_BULK_LATENCY = 2,
238 };
239 
240 struct i40e_ring_container {
241 #define I40E_MAX_RINGPAIR_PER_VECTOR 8
242 	/* array of pointers to rings */
243 	struct i40e_ring *ring[I40E_MAX_RINGPAIR_PER_VECTOR];
244 	unsigned int total_bytes;	/* total bytes processed this int */
245 	unsigned int total_packets;	/* total packets processed this int */
246 	u16 count;
247 	enum i40e_latency_range latency_range;
248 	u16 itr;
249 };
250 
251 void i40e_alloc_rx_buffers(struct i40e_ring *rxr, u16 cleaned_count);
252 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
253 void i40e_clean_tx_ring(struct i40e_ring *tx_ring);
254 void i40e_clean_rx_ring(struct i40e_ring *rx_ring);
255 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring);
256 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring);
257 void i40e_free_tx_resources(struct i40e_ring *tx_ring);
258 void i40e_free_rx_resources(struct i40e_ring *rx_ring);
259 int i40e_napi_poll(struct napi_struct *napi, int budget);
260