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
|
/*
* Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of Texas Instruments Incorporated nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* File : pru_virtqueue.c
*
* Summary : A virtual queue implementation to simplify vring usage.
*
* Notes :
* - Implementaion of the interface described in "pru_virtqueue.h"
*/
#include <pru_virtqueue.h>
#ifdef __GNUC__
#include <pru/io.h>
#else
volatile register uint32_t __R31;
#endif
/* bit 5 is the valid strobe to generate system events with __R31 */
#define INT_ENABLE (1 << 5)
/* __R31[3:0] can generate 15-0 which maps to system events 31-16
* e.g. to generate PRU-ICSS System Event 17 (pru_mst_intr[1])
* __R31 = (INT_ENABLE | (17 - INT_OFFSET));
*/
#define INT_OFFSET 16
void pru_virtqueue_init(
struct pru_virtqueue *vq,
struct fw_rsc_vdev_vring *vring,
uint32_t to_arm_event,
uint32_t from_arm_event
)
{
vq->id = vring->notifyid;
vq->to_arm_event = to_arm_event;
vq->from_arm_event = from_arm_event;
vq->last_avail_idx = 0;
vring_init(&vq->vring, vring->num, (void*)vring->da, vring->align);
}
int16_t pru_virtqueue_get_avail_buf(
struct pru_virtqueue *vq,
void **buf,
uint32_t *len
)
{
int16_t head;
struct vring_desc desc;
struct vring_avail *avail;
avail = vq->vring.avail;
/* There's nothing available */
if (vq->last_avail_idx == avail->idx)
return PRU_VIRTQUEUE_NO_BUF_AVAILABLE;
/*
* Grab the next descriptor number the ARM host is advertising, and
* increment the last available index we've seen.
*/
head = avail->ring[vq->last_avail_idx++ & (vq->vring.num - 1)];
desc = vq->vring.desc[head];
*buf = (void *)(uint32_t)desc.addr;
*len = desc.len;
return (head);
}
int16_t pru_virtqueue_add_used_buf(
struct pru_virtqueue *vq,
int16_t head,
uint32_t len
)
{
struct vring_used_elem *used_elem;
uint32_t num;
struct vring_used *used;
num = vq->vring.num;
used = vq->vring.used;
if (head > (int)num)
return PRU_VIRTQUEUE_INVALID_HEAD;
/*
* The virtqueue's vring contains a ring of used buffers. Get a pointer to
* the next entry in that used ring.
*/
used_elem = &used->ring[used->idx++ & (num - 1)];
used_elem->id = head;
used_elem->len = len;
return PRU_VIRTQUEUE_SUCCESS;
}
int16_t pru_virtqueue_kick(
struct pru_virtqueue *vq
)
{
/* If requested, do not kick the ARM host */
if (vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
return PRU_VIRTQUEUE_NO_KICK;
/* Generate a system event to kick the ARM */
__R31 = (INT_ENABLE | (vq->to_arm_event - INT_OFFSET));
return PRU_VIRTQUEUE_SUCCESS;
}
|
