xref: /linux/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h (revision 8804d970fab45726b3c7cd7f240b31122aa94219)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (c) Meta Platforms, Inc. and affiliates. */
3 
4 #ifndef _FBNIC_TXRX_H_
5 #define _FBNIC_TXRX_H_
6 
7 #include <linux/netdevice.h>
8 #include <linux/skbuff.h>
9 #include <linux/types.h>
10 #include <linux/u64_stats_sync.h>
11 #include <net/xdp.h>
12 
13 struct fbnic_net;
14 
15 /* Guarantee we have space needed for storing the buffer
16  * To store the buffer we need:
17  *	1 descriptor per page
18  *	+ 1 descriptor for skb head
19  *	+ 2 descriptors for metadata and optional metadata
20  *	+ 7 descriptors to keep tail out of the same cacheline as head
21  * If we cannot guarantee that then we should return TX_BUSY
22  */
23 #define FBNIC_MAX_SKB_DESC	(MAX_SKB_FRAGS + 10)
24 #define FBNIC_TX_DESC_WAKEUP	(FBNIC_MAX_SKB_DESC * 2)
25 #define FBNIC_TX_DESC_MIN	roundup_pow_of_two(FBNIC_TX_DESC_WAKEUP)
26 
27 /* To receive the worst case packet we need:
28  *	1 descriptor for primary metadata
29  *	+ 1 descriptor for optional metadata
30  *	+ 1 descriptor for headers
31  *	+ 4 descriptors for payload
32  */
33 #define FBNIC_MAX_RX_PKT_DESC	7
34 #define FBNIC_RX_DESC_MIN	roundup_pow_of_two(FBNIC_MAX_RX_PKT_DESC * 2)
35 
36 #define FBNIC_MAX_TXQS			128u
37 #define FBNIC_MAX_RXQS			128u
38 #define FBNIC_MAX_XDPQS			128u
39 
40 /* These apply to TWQs, TCQ, RCQ */
41 #define FBNIC_QUEUE_SIZE_MIN		16u
42 #define FBNIC_QUEUE_SIZE_MAX		SZ_64K
43 
44 #define FBNIC_TXQ_SIZE_DEFAULT		1024
45 #define FBNIC_HPQ_SIZE_DEFAULT		256
46 #define FBNIC_PPQ_SIZE_DEFAULT		256
47 #define FBNIC_RCQ_SIZE_DEFAULT		1024
48 #define FBNIC_TX_USECS_DEFAULT		35
49 #define FBNIC_RX_USECS_DEFAULT		30
50 #define FBNIC_RX_FRAMES_DEFAULT		0
51 
52 #define FBNIC_RX_TROOM \
53 	SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
54 #define FBNIC_RX_HROOM_PAD		128
55 #define FBNIC_RX_HROOM \
56 	(ALIGN(FBNIC_RX_TROOM + FBNIC_RX_HROOM_PAD, 128) - FBNIC_RX_TROOM)
57 #define FBNIC_RX_PAD			0
58 #define FBNIC_RX_PAYLD_OFFSET		0
59 #define FBNIC_RX_PAYLD_PG_CL		0
60 
61 #define FBNIC_RING_F_DISABLED		BIT(0)
62 #define FBNIC_RING_F_CTX		BIT(1)
63 #define FBNIC_RING_F_STATS		BIT(2)	/* Ring's stats may be used */
64 
65 #define FBNIC_HDS_THRESH_MAX \
66 	(4096 - FBNIC_RX_HROOM - FBNIC_RX_TROOM - FBNIC_RX_PAD)
67 #define FBNIC_HDS_THRESH_DEFAULT \
68 	(1536 - FBNIC_RX_PAD)
69 #define FBNIC_HDR_BYTES_MIN		128
70 
71 struct fbnic_pkt_buff {
72 	struct xdp_buff buff;
73 	ktime_t hwtstamp;
74 	bool add_frag_failed;
75 };
76 
77 struct fbnic_queue_stats {
78 	u64 packets;
79 	u64 bytes;
80 	union {
81 		struct {
82 			u64 csum_partial;
83 			u64 lso;
84 			u64 ts_packets;
85 			u64 ts_lost;
86 			u64 stop;
87 			u64 wake;
88 		} twq;
89 		struct {
90 			u64 alloc_failed;
91 			u64 csum_complete;
92 			u64 csum_none;
93 			u64 length_errors;
94 		} rx;
95 	};
96 	u64 dropped;
97 	struct u64_stats_sync syncp;
98 };
99 
100 #define FBNIC_PAGECNT_BIAS_MAX	PAGE_SIZE
101 
102 struct fbnic_rx_buf {
103 	netmem_ref netmem;
104 	long pagecnt_bias;
105 };
106 
107 struct fbnic_ring {
108 	/* Pointer to buffer specific info */
109 	union {
110 		struct fbnic_pkt_buff *pkt;	/* RCQ */
111 		struct fbnic_rx_buf *rx_buf;	/* BDQ */
112 		void **tx_buf;			/* TWQ */
113 		void *buffer;			/* Generic pointer */
114 	};
115 
116 	u32 __iomem *doorbell;		/* Pointer to CSR space for ring */
117 	__le64 *desc;			/* Descriptor ring memory */
118 	u16 size_mask;			/* Size of ring in descriptors - 1 */
119 	u8 q_idx;			/* Logical netdev ring index */
120 	u8 flags;			/* Ring flags (FBNIC_RING_F_*) */
121 
122 	u32 head, tail;			/* Head/Tail of ring */
123 
124 	union {
125 		/* Rx BDQs only */
126 		struct page_pool *page_pool;
127 
128 		/* Deferred_head is used to cache the head for TWQ1 if
129 		 * an attempt is made to clean TWQ1 with zero napi_budget.
130 		 * We do not use it for any other ring.
131 		 */
132 		s32 deferred_head;
133 	};
134 
135 	struct fbnic_queue_stats stats;
136 
137 	/* Slow path fields follow */
138 	dma_addr_t dma;			/* Phys addr of descriptor memory */
139 	size_t size;			/* Size of descriptor ring in memory */
140 };
141 
142 struct fbnic_q_triad {
143 	struct fbnic_ring sub0, sub1, cmpl;
144 	struct xdp_rxq_info xdp_rxq;
145 };
146 
147 struct fbnic_napi_vector {
148 	struct napi_struct napi;
149 	struct device *dev;		/* Device for DMA unmapping */
150 	struct fbnic_dev *fbd;
151 
152 	u16 v_idx;
153 	u8 txt_count;
154 	u8 rxt_count;
155 
156 	struct fbnic_q_triad qt[];
157 };
158 
159 extern const struct netdev_queue_mgmt_ops fbnic_queue_mgmt_ops;
160 
161 netdev_tx_t fbnic_xmit_frame(struct sk_buff *skb, struct net_device *dev);
162 netdev_features_t
163 fbnic_features_check(struct sk_buff *skb, struct net_device *dev,
164 		     netdev_features_t features);
165 
166 void fbnic_aggregate_ring_rx_counters(struct fbnic_net *fbn,
167 				      struct fbnic_ring *rxr);
168 void fbnic_aggregate_ring_tx_counters(struct fbnic_net *fbn,
169 				      struct fbnic_ring *txr);
170 
171 int fbnic_alloc_napi_vectors(struct fbnic_net *fbn);
172 void fbnic_free_napi_vectors(struct fbnic_net *fbn);
173 int fbnic_alloc_resources(struct fbnic_net *fbn);
174 void fbnic_free_resources(struct fbnic_net *fbn);
175 int fbnic_set_netif_queues(struct fbnic_net *fbn);
176 void fbnic_reset_netif_queues(struct fbnic_net *fbn);
177 irqreturn_t fbnic_msix_clean_rings(int irq, void *data);
178 void fbnic_napi_enable(struct fbnic_net *fbn);
179 void fbnic_napi_disable(struct fbnic_net *fbn);
180 void fbnic_enable(struct fbnic_net *fbn);
181 void fbnic_disable(struct fbnic_net *fbn);
182 void fbnic_flush(struct fbnic_net *fbn);
183 void fbnic_fill(struct fbnic_net *fbn);
184 
185 void fbnic_napi_depletion_check(struct net_device *netdev);
186 int fbnic_wait_all_queues_idle(struct fbnic_dev *fbd, bool may_fail);
187 
188 static inline int fbnic_napi_idx(const struct fbnic_napi_vector *nv)
189 {
190 	return nv->v_idx - FBNIC_NON_NAPI_VECTORS;
191 }
192 
193 #endif /* _FBNIC_TXRX_H_ */
194