xref: /linux/drivers/net/ethernet/cisco/enic/vnic_rq.h (revision 288440de9e5fdb4a3ff73864850f080c1250fc81)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
4  * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
5  */
6 
7 #ifndef _VNIC_RQ_H_
8 #define _VNIC_RQ_H_
9 
10 #include <linux/pci.h>
11 #include <linux/netdevice.h>
12 
13 #include "vnic_dev.h"
14 #include "vnic_cq.h"
15 
16 /* Receive queue control */
17 struct vnic_rq_ctrl {
18 	u64 ring_base;			/* 0x00 */
19 	u32 ring_size;			/* 0x08 */
20 	u32 pad0;
21 	u32 posted_index;		/* 0x10 */
22 	u32 pad1;
23 	u32 cq_index;			/* 0x18 */
24 	u32 pad2;
25 	u32 enable;			/* 0x20 */
26 	u32 pad3;
27 	u32 running;			/* 0x28 */
28 	u32 pad4;
29 	u32 fetch_index;		/* 0x30 */
30 	u32 pad5;
31 	u32 error_interrupt_enable;	/* 0x38 */
32 	u32 pad6;
33 	u32 error_interrupt_offset;	/* 0x40 */
34 	u32 pad7;
35 	u32 error_status;		/* 0x48 */
36 	u32 pad8;
37 	u32 dropped_packet_count;	/* 0x50 */
38 	u32 pad9;
39 	u32 dropped_packet_count_rc;	/* 0x58 */
40 	u32 pad10;
41 };
42 
43 /* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
44 #define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
45 #define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
46 #define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
47 	((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
48 	VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
49 #define VNIC_RQ_BUF_BLK_SZ(entries) \
50 	(VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
51 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
52 	DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
53 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
54 
55 struct vnic_rq_buf {
56 	struct vnic_rq_buf *next;
57 	dma_addr_t dma_addr;
58 	void *os_buf;
59 	unsigned int os_buf_index;
60 	unsigned int len;
61 	unsigned int index;
62 	void *desc;
63 	uint64_t wr_id;
64 };
65 
66 enum enic_poll_state {
67 	ENIC_POLL_STATE_IDLE,
68 	ENIC_POLL_STATE_NAPI,
69 	ENIC_POLL_STATE_POLL
70 };
71 
72 struct vnic_rq {
73 	unsigned int index;
74 	struct vnic_dev *vdev;
75 	struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
76 	struct vnic_dev_ring ring;
77 	struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
78 	struct vnic_rq_buf *to_use;
79 	struct vnic_rq_buf *to_clean;
80 	void *os_buf_head;
81 	unsigned int pkts_outstanding;
82 };
83 
84 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
85 {
86 	/* how many does SW own? */
87 	return rq->ring.desc_avail;
88 }
89 
90 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
91 {
92 	/* how many does HW own? */
93 	return rq->ring.desc_count - rq->ring.desc_avail - 1;
94 }
95 
96 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
97 {
98 	return rq->to_use->desc;
99 }
100 
101 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
102 {
103 	return rq->to_use->index;
104 }
105 
106 static inline void vnic_rq_post(struct vnic_rq *rq,
107 	void *os_buf, unsigned int os_buf_index,
108 	dma_addr_t dma_addr, unsigned int len,
109 	uint64_t wrid)
110 {
111 	struct vnic_rq_buf *buf = rq->to_use;
112 
113 	buf->os_buf = os_buf;
114 	buf->os_buf_index = os_buf_index;
115 	buf->dma_addr = dma_addr;
116 	buf->len = len;
117 	buf->wr_id = wrid;
118 
119 	buf = buf->next;
120 	rq->to_use = buf;
121 	rq->ring.desc_avail--;
122 
123 	/* Move the posted_index every nth descriptor
124 	 */
125 
126 #ifndef VNIC_RQ_RETURN_RATE
127 #define VNIC_RQ_RETURN_RATE		0xf	/* keep 2^n - 1 */
128 #endif
129 
130 	if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
131 		/* Adding write memory barrier prevents compiler and/or CPU
132 		 * reordering, thus avoiding descriptor posting before
133 		 * descriptor is initialized. Otherwise, hardware can read
134 		 * stale descriptor fields.
135 		 */
136 		wmb();
137 		iowrite32(buf->index, &rq->ctrl->posted_index);
138 	}
139 }
140 
141 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
142 {
143 	rq->ring.desc_avail += count;
144 }
145 
146 enum desc_return_options {
147 	VNIC_RQ_RETURN_DESC,
148 	VNIC_RQ_DEFER_RETURN_DESC,
149 };
150 
151 static inline void vnic_rq_service(struct vnic_rq *rq,
152 	struct cq_desc *cq_desc, u16 completed_index,
153 	int desc_return, void (*buf_service)(struct vnic_rq *rq,
154 	struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
155 	int skipped, void *opaque), void *opaque)
156 {
157 	struct vnic_rq_buf *buf;
158 	int skipped;
159 
160 	buf = rq->to_clean;
161 	while (1) {
162 
163 		skipped = (buf->index != completed_index);
164 
165 		(*buf_service)(rq, cq_desc, buf, skipped, opaque);
166 
167 		if (desc_return == VNIC_RQ_RETURN_DESC)
168 			rq->ring.desc_avail++;
169 
170 		rq->to_clean = buf->next;
171 
172 		if (!skipped)
173 			break;
174 
175 		buf = rq->to_clean;
176 	}
177 }
178 
179 static inline int vnic_rq_fill(struct vnic_rq *rq,
180 	int (*buf_fill)(struct vnic_rq *rq))
181 {
182 	int err;
183 
184 	while (vnic_rq_desc_avail(rq) > 0) {
185 
186 		err = (*buf_fill)(rq);
187 		if (err)
188 			return err;
189 	}
190 
191 	return 0;
192 }
193 
194 void vnic_rq_free(struct vnic_rq *rq);
195 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
196 	unsigned int desc_count, unsigned int desc_size);
197 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
198 	unsigned int error_interrupt_enable,
199 	unsigned int error_interrupt_offset);
200 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
201 void vnic_rq_enable(struct vnic_rq *rq);
202 int vnic_rq_disable(struct vnic_rq *rq);
203 void vnic_rq_clean(struct vnic_rq *rq,
204 	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
205 
206 #endif /* _VNIC_RQ_H_ */
207