1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/* SPDX-License-Identifier: GPL-2.0 */
/* XDP user-space ring structure
* Copyright(c) 2018 Intel Corporation.
*/
#ifndef _LINUX_XSK_QUEUE_H
#define _LINUX_XSK_QUEUE_H
#include <linux/types.h>
#include <linux/if_xdp.h>
#include "xdp_umem_props.h"
#define RX_BATCH_SIZE 16
struct xdp_ring {
u32 producer ____cacheline_aligned_in_smp;
u32 consumer ____cacheline_aligned_in_smp;
};
/* Used for the RX and TX queues for packets */
struct xdp_rxtx_ring {
struct xdp_ring ptrs;
struct xdp_desc desc[0] ____cacheline_aligned_in_smp;
};
/* Used for the fill and completion queues for buffers */
struct xdp_umem_ring {
struct xdp_ring ptrs;
u64 desc[0] ____cacheline_aligned_in_smp;
};
struct xsk_queue {
struct xdp_umem_props umem_props;
u32 ring_mask;
u32 nentries;
u32 prod_head;
u32 prod_tail;
u32 cons_head;
u32 cons_tail;
struct xdp_ring *ring;
u64 invalid_descs;
};
/* Common functions operating for both RXTX and umem queues */
static inline u64 xskq_nb_invalid_descs(struct xsk_queue *q)
{
return q ? q->invalid_descs : 0;
}
static inline u32 xskq_nb_avail(struct xsk_queue *q, u32 dcnt)
{
u32 entries = q->prod_tail - q->cons_tail;
if (entries == 0) {
/* Refresh the local pointer */
q->prod_tail = READ_ONCE(q->ring->producer);
entries = q->prod_tail - q->cons_tail;
}
return (entries > dcnt) ? dcnt : entries;
}
static inline u32 xskq_nb_free(struct xsk_queue *q, u32 producer, u32 dcnt)
{
u32 free_entries = q->nentries - (producer - q->cons_tail);
if (free_entries >= dcnt)
return free_entries;
/* Refresh the local tail pointer */
q->cons_tail = READ_ONCE(q->ring->consumer);
return q->nentries - (producer - q->cons_tail);
}
/* UMEM queue */
static inline bool xskq_is_valid_addr(struct xsk_queue *q, u64 addr)
{
if (addr >= q->umem_props.size) {
q->invalid_descs++;
return false;
}
return true;
}
static inline u64 *xskq_validate_addr(struct xsk_queue *q, u64 *addr)
{
while (q->cons_tail != q->cons_head) {
struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
unsigned int idx = q->cons_tail & q->ring_mask;
*addr = READ_ONCE(ring->desc[idx]) & q->umem_props.chunk_mask;
if (xskq_is_valid_addr(q, *addr))
return addr;
q->cons_tail++;
}
return NULL;
}
static inline u64 *xskq_peek_addr(struct xsk_queue *q, u64 *addr)
{
if (q->cons_tail == q->cons_head) {
WRITE_ONCE(q->ring->consumer, q->cons_tail);
q->cons_head = q->cons_tail + xskq_nb_avail(q, RX_BATCH_SIZE);
/* Order consumer and data */
smp_rmb();
}
return xskq_validate_addr(q, addr);
}
static inline void xskq_discard_addr(struct xsk_queue *q)
{
q->cons_tail++;
}
static inline int xskq_produce_addr(struct xsk_queue *q, u64 addr)
{
struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
ring->desc[q->prod_tail++ & q->ring_mask] = addr;
/* Order producer and data */
smp_wmb();
WRITE_ONCE(q->ring->producer, q->prod_tail);
return 0;
}
static inline int xskq_reserve_addr(struct xsk_queue *q)
{
if (xskq_nb_free(q, q->prod_head, 1) == 0)
return -ENOSPC;
q->prod_head++;
return 0;
}
/* Rx/Tx queue */
static inline bool xskq_is_valid_desc(struct xsk_queue *q, struct xdp_desc *d)
{
if (!xskq_is_valid_addr(q, d->addr))
return false;
if (((d->addr + d->len) & q->umem_props.chunk_mask) !=
(d->addr & q->umem_props.chunk_mask)) {
q->invalid_descs++;
return false;
}
return true;
}
static inline struct xdp_desc *xskq_validate_desc(struct xsk_queue *q,
struct xdp_desc *desc)
{
while (q->cons_tail != q->cons_head) {
struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
unsigned int idx = q->cons_tail & q->ring_mask;
*desc = READ_ONCE(ring->desc[idx]);
if (xskq_is_valid_desc(q, desc))
return desc;
q->cons_tail++;
}
return NULL;
}
static inline struct xdp_desc *xskq_peek_desc(struct xsk_queue *q,
struct xdp_desc *desc)
{
if (q->cons_tail == q->cons_head) {
WRITE_ONCE(q->ring->consumer, q->cons_tail);
q->cons_head = q->cons_tail + xskq_nb_avail(q, RX_BATCH_SIZE);
/* Order consumer and data */
smp_rmb();
}
return xskq_validate_desc(q, desc);
}
static inline void xskq_discard_desc(struct xsk_queue *q)
{
q->cons_tail++;
}
static inline int xskq_produce_batch_desc(struct xsk_queue *q,
u64 addr, u32 len)
{
struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
unsigned int idx;
if (xskq_nb_free(q, q->prod_head, 1) == 0)
return -ENOSPC;
idx = (q->prod_head++) & q->ring_mask;
ring->desc[idx].addr = addr;
ring->desc[idx].len = len;
return 0;
}
static inline void xskq_produce_flush_desc(struct xsk_queue *q)
{
/* Order producer and data */
smp_wmb();
q->prod_tail = q->prod_head,
WRITE_ONCE(q->ring->producer, q->prod_tail);
}
static inline bool xskq_full_desc(struct xsk_queue *q)
{
return xskq_nb_avail(q, q->nentries) == q->nentries;
}
static inline bool xskq_empty_desc(struct xsk_queue *q)
{
return xskq_nb_free(q, q->prod_tail, 1) == q->nentries;
}
void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props);
struct xsk_queue *xskq_create(u32 nentries, bool umem_queue);
void xskq_destroy(struct xsk_queue *q_ops);
#endif /* _LINUX_XSK_QUEUE_H */
|
