xref: /linux/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h (revision c7546e2c3cb739a3c1a2f5acaf9bb629d401afe5)
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 #define FBNIC_MAX_TXQS			128u
28 #define FBNIC_MAX_RXQS			128u
29 
30 #define FBNIC_TXQ_SIZE_DEFAULT		1024
31 #define FBNIC_HPQ_SIZE_DEFAULT		256
32 #define FBNIC_PPQ_SIZE_DEFAULT		256
33 #define FBNIC_RCQ_SIZE_DEFAULT		1024
34 
35 #define FBNIC_RX_TROOM \
36 	SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
37 #define FBNIC_RX_HROOM \
38 	(ALIGN(FBNIC_RX_TROOM + NET_SKB_PAD, 128) - FBNIC_RX_TROOM)
39 #define FBNIC_RX_PAD			0
40 #define FBNIC_RX_MAX_HDR		(1536 - FBNIC_RX_PAD)
41 #define FBNIC_RX_PAYLD_OFFSET		0
42 #define FBNIC_RX_PAYLD_PG_CL		0
43 
44 #define FBNIC_RING_F_DISABLED		BIT(0)
45 #define FBNIC_RING_F_CTX		BIT(1)
46 #define FBNIC_RING_F_STATS		BIT(2)	/* Ring's stats may be used */
47 
48 struct fbnic_pkt_buff {
49 	struct xdp_buff buff;
50 	u32 data_truesize;
51 	u16 data_len;
52 	u16 nr_frags;
53 };
54 
55 struct fbnic_queue_stats {
56 	u64 packets;
57 	u64 bytes;
58 	u64 dropped;
59 	struct u64_stats_sync syncp;
60 };
61 
62 /* Pagecnt bias is long max to reserve the last bit to catch overflow
63  * cases where if we overcharge the bias it will flip over to be negative.
64  */
65 #define PAGECNT_BIAS_MAX	LONG_MAX
66 struct fbnic_rx_buf {
67 	struct page *page;
68 	long pagecnt_bias;
69 };
70 
71 struct fbnic_ring {
72 	/* Pointer to buffer specific info */
73 	union {
74 		struct fbnic_pkt_buff *pkt;	/* RCQ */
75 		struct fbnic_rx_buf *rx_buf;	/* BDQ */
76 		void **tx_buf;			/* TWQ */
77 		void *buffer;			/* Generic pointer */
78 	};
79 
80 	u32 __iomem *doorbell;		/* Pointer to CSR space for ring */
81 	__le64 *desc;			/* Descriptor ring memory */
82 	u16 size_mask;			/* Size of ring in descriptors - 1 */
83 	u8 q_idx;			/* Logical netdev ring index */
84 	u8 flags;			/* Ring flags (FBNIC_RING_F_*) */
85 
86 	u32 head, tail;			/* Head/Tail of ring */
87 
88 	struct fbnic_queue_stats stats;
89 
90 	/* Slow path fields follow */
91 	dma_addr_t dma;			/* Phys addr of descriptor memory */
92 	size_t size;			/* Size of descriptor ring in memory */
93 };
94 
95 struct fbnic_q_triad {
96 	struct fbnic_ring sub0, sub1, cmpl;
97 };
98 
99 struct fbnic_napi_vector {
100 	struct napi_struct napi;
101 	struct device *dev;		/* Device for DMA unmapping */
102 	struct page_pool *page_pool;
103 	struct fbnic_dev *fbd;
104 	char name[IFNAMSIZ + 9];
105 
106 	u16 v_idx;
107 	u8 txt_count;
108 	u8 rxt_count;
109 
110 	struct list_head napis;
111 
112 	struct fbnic_q_triad qt[];
113 };
114 
115 #define FBNIC_MAX_TXQS			128u
116 #define FBNIC_MAX_RXQS			128u
117 
118 netdev_tx_t fbnic_xmit_frame(struct sk_buff *skb, struct net_device *dev);
119 netdev_features_t
120 fbnic_features_check(struct sk_buff *skb, struct net_device *dev,
121 		     netdev_features_t features);
122 
123 int fbnic_alloc_napi_vectors(struct fbnic_net *fbn);
124 void fbnic_free_napi_vectors(struct fbnic_net *fbn);
125 int fbnic_alloc_resources(struct fbnic_net *fbn);
126 void fbnic_free_resources(struct fbnic_net *fbn);
127 void fbnic_napi_enable(struct fbnic_net *fbn);
128 void fbnic_napi_disable(struct fbnic_net *fbn);
129 void fbnic_enable(struct fbnic_net *fbn);
130 void fbnic_disable(struct fbnic_net *fbn);
131 void fbnic_flush(struct fbnic_net *fbn);
132 void fbnic_fill(struct fbnic_net *fbn);
133 
134 void fbnic_napi_depletion_check(struct net_device *netdev);
135 int fbnic_wait_all_queues_idle(struct fbnic_dev *fbd, bool may_fail);
136 
137 #endif /* _FBNIC_TXRX_H_ */
138