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 bool is_tls_ring);
52
53 void
54 vn_ring_destroy(struct vn_ring *ring);
55
56 uint64_t
57 vn_ring_get_id(struct vn_ring *ring);
58
59 uint32_t
60 vn_ring_load_status(const struct vn_ring *ring);
61
62 void
63 vn_ring_unset_status_bits(struct vn_ring *ring, uint32_t mask);
64
65 bool
66 vn_ring_get_seqno_status(struct vn_ring *ring, uint32_t seqno);
67
68 void
69 vn_ring_wait_all(struct vn_ring *ring);
70
71 struct vn_ring_submit_command {
72 /* empty command implies errors */
73 struct vn_cs_encoder command;
74 struct vn_cs_encoder_buffer buffer;
75 /* non-zero implies waiting */
76 size_t reply_size;
77
78 /* when reply_size is non-zero, NULL can be returned on errors */
79 struct vn_renderer_shmem *reply_shmem;
80 struct vn_cs_decoder reply;
81
82 /* valid when ring submission succeeds */
83 bool ring_seqno_valid;
84 uint32_t ring_seqno;
85 };
86
87 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)88 vn_ring_submit_command_init(struct vn_ring *ring,
89 struct vn_ring_submit_command *submit,
90 void *cmd_data,
91 size_t cmd_size,
92 size_t reply_size)
93 {
94 submit->buffer = VN_CS_ENCODER_BUFFER_INITIALIZER(cmd_data);
95 submit->command = VN_CS_ENCODER_INITIALIZER(&submit->buffer, cmd_size);
96
97 submit->reply_size = reply_size;
98 submit->reply_shmem = NULL;
99
100 submit->ring_seqno_valid = false;
101
102 return &submit->command;
103 }
104
105 static inline struct vn_cs_decoder *
vn_ring_get_command_reply(struct vn_ring * ring,struct vn_ring_submit_command * submit)106 vn_ring_get_command_reply(struct vn_ring *ring,
107 struct vn_ring_submit_command *submit)
108 {
109 return submit->reply_shmem ? &submit->reply : NULL;
110 }
111
112 void
113 vn_ring_free_command_reply(struct vn_ring *ring,
114 struct vn_ring_submit_command *submit);
115
116 void
117 vn_ring_submit_command(struct vn_ring *ring,
118 struct vn_ring_submit_command *submit);
119
120 VkResult
121 vn_ring_submit_command_simple(struct vn_ring *ring,
122 const struct vn_cs_encoder *cs);
123
124 VkResult
125 vn_ring_submit_roundtrip(struct vn_ring *ring, uint64_t *roundtrip_seqno);
126
127 void
128 vn_ring_wait_roundtrip(struct vn_ring *ring, uint64_t roundtrip_seqno);
129
130 static inline void
vn_ring_roundtrip(struct vn_ring * ring)131 vn_ring_roundtrip(struct vn_ring *ring)
132 {
133 uint64_t roundtrip_seqno;
134 if (vn_ring_submit_roundtrip(ring, &roundtrip_seqno) == VK_SUCCESS)
135 vn_ring_wait_roundtrip(ring, roundtrip_seqno);
136 }
137
138 #endif /* VN_RING_H */
139