1 /*
2 * Copyright 2021 Google LLC
3 * SPDX-License-Identifier: MIT
4 */
5
6 #ifndef VN_RING_H
7 #define VN_RING_H
8
9 #include "vn_common.h"
10
11 #include "vn_cs.h"
12
13 /**
14 * A ring is a single-producer and single-consumer circular buffer. The data
15 * in the buffer are produced and consumed in order. An externally-defined
16 * mechanism is required for ring setup and notifications in both directions.
17 * Notifications for new data from the producer are needed only when the
18 * consumer is not actively polling, which is indicated by the ring status.
19 *
20 * For venus, the data are plain venus commands. When a venus command is
21 * consumed from the ring's perspective, there can still be ongoing CPU and/or
22 * GPU works. This is not an issue when the works generated by following
23 * venus commands are correctly queued after the ongoing works. There are
24 * also venus commands that facilitate polling or waiting for ongoing works.
25 */
26
27 /* the layout of a ring in a shmem */
28 struct vn_ring_layout {
29 size_t head_offset;
30 size_t tail_offset;
31 size_t status_offset;
32
33 size_t buffer_offset;
34 size_t buffer_size;
35
36 size_t extra_offset;
37 size_t extra_size;
38
39 size_t shmem_size;
40 };
41
42 void
43 vn_ring_get_layout(size_t buf_size,
44 size_t extra_size,
45 struct vn_ring_layout *layout);
46
47 struct vn_ring *
48 vn_ring_create(struct vn_instance *instance,
49 const struct vn_ring_layout *layout,
50 uint8_t direct_order);
51
52 void
53 vn_ring_destroy(struct vn_ring *ring);
54
55 uint64_t
56 vn_ring_get_id(struct vn_ring *ring);
57
58 uint32_t
59 vn_ring_load_status(const struct vn_ring *ring);
60
61 void
62 vn_ring_unset_status_bits(struct vn_ring *ring, uint32_t mask);
63
64 bool
65 vn_ring_get_seqno_status(struct vn_ring *ring, uint32_t seqno);
66
67 void
68 vn_ring_wait_all(struct vn_ring *ring);
69
70 struct vn_ring_submit_command {
71 /* empty command implies errors */
72 struct vn_cs_encoder command;
73 struct vn_cs_encoder_buffer buffer;
74 /* non-zero implies waiting */
75 size_t reply_size;
76
77 /* when reply_size is non-zero, NULL can be returned on errors */
78 struct vn_renderer_shmem *reply_shmem;
79 struct vn_cs_decoder reply;
80
81 /* valid when ring submission succeeds */
82 bool ring_seqno_valid;
83 uint32_t ring_seqno;
84 };
85
86 static inline struct vn_cs_encoder *
vn_ring_submit_command_init(struct vn_ring * ring,struct vn_ring_submit_command * submit,void * cmd_data,size_t cmd_size,size_t reply_size)87 vn_ring_submit_command_init(struct vn_ring *ring,
88 struct vn_ring_submit_command *submit,
89 void *cmd_data,
90 size_t cmd_size,
91 size_t reply_size)
92 {
93 submit->buffer = VN_CS_ENCODER_BUFFER_INITIALIZER(cmd_data);
94 submit->command = VN_CS_ENCODER_INITIALIZER(&submit->buffer, cmd_size);
95
96 submit->reply_size = reply_size;
97 submit->reply_shmem = NULL;
98
99 submit->ring_seqno_valid = false;
100
101 return &submit->command;
102 }
103
104 static inline struct vn_cs_decoder *
vn_ring_get_command_reply(struct vn_ring * ring,struct vn_ring_submit_command * submit)105 vn_ring_get_command_reply(struct vn_ring *ring,
106 struct vn_ring_submit_command *submit)
107 {
108 return submit->reply_shmem ? &submit->reply : NULL;
109 }
110
111 void
112 vn_ring_free_command_reply(struct vn_ring *ring,
113 struct vn_ring_submit_command *submit);
114
115 void
116 vn_ring_submit_command(struct vn_ring *ring,
117 struct vn_ring_submit_command *submit);
118
119 VkResult
120 vn_ring_submit_command_simple(struct vn_ring *ring,
121 const struct vn_cs_encoder *cs);
122
123 #endif /* VN_RING_H */
124