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
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
/*
* Copyright © 2016 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/**
* An implementation of the transform feedback driver hooks for Haswell
* and later hardware. This uses MI_MATH to compute the number of vertices
* written (for use by DrawTransformFeedback()) without any CPU<->GPU
* synchronization which could stall.
*/
#include "brw_context.h"
#include "brw_state.h"
#include "brw_defines.h"
#include "intel_batchbuffer.h"
#include "intel_buffer_objects.h"
#include "main/transformfeedback.h"
/**
* We store several values in obj->prim_count_bo:
*
* [4x 32-bit values]: Final Number of Vertices Written
* [4x 32-bit values]: Tally of Primitives Written So Far
* [4x 64-bit values]: Starting SO_NUM_PRIMS_WRITTEN Counter Snapshots
*
* The first set of values is used by DrawTransformFeedback(), which
* copies one of them into the 3DPRIM_VERTEX_COUNT register and performs
* an indirect draw. The other values are just temporary storage.
*/
#define TALLY_OFFSET (BRW_MAX_XFB_STREAMS * sizeof(uint32_t))
#define START_OFFSET (TALLY_OFFSET * 2)
/**
* Store the SO_NUM_PRIMS_WRITTEN counters for each stream (4 uint64_t values)
* to prim_count_bo.
*/
static void
save_prim_start_values(struct brw_context *brw,
struct brw_transform_feedback_object *obj)
{
/* Flush any drawing so that the counters have the right values. */
brw_emit_mi_flush(brw);
/* Emit MI_STORE_REGISTER_MEM commands to write the values. */
for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
brw_store_register_mem64(brw, obj->prim_count_bo,
GEN7_SO_NUM_PRIMS_WRITTEN(i),
START_OFFSET + i * sizeof(uint64_t));
}
}
/**
* Compute the number of primitives written during our most recent
* transform feedback activity (the current SO_NUM_PRIMS_WRITTEN value
* minus the stashed "start" value), and add it to our running tally.
*
* If \p finalize is true, also compute the number of vertices written
* (by multiplying by the number of vertices per primitive), and store
* that to the "final" location.
*
* Otherwise, just overwrite the old tally with the new one.
*/
static void
tally_prims_written(struct brw_context *brw,
struct brw_transform_feedback_object *obj,
bool finalize)
{
/* Flush any drawing so that the counters have the right values. */
brw_emit_mi_flush(brw);
for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
/* GPR0 = Tally */
brw_load_register_imm32(brw, HSW_CS_GPR(0) + 4, 0);
brw_load_register_mem(brw, HSW_CS_GPR(0), obj->prim_count_bo,
I915_GEM_DOMAIN_INSTRUCTION,
I915_GEM_DOMAIN_INSTRUCTION,
TALLY_OFFSET + i * sizeof(uint32_t));
if (!obj->base.Paused) {
/* GPR1 = Start Snapshot */
brw_load_register_mem64(brw, HSW_CS_GPR(1), obj->prim_count_bo,
I915_GEM_DOMAIN_INSTRUCTION,
I915_GEM_DOMAIN_INSTRUCTION,
START_OFFSET + i * sizeof(uint64_t));
/* GPR2 = Ending Snapshot */
brw_load_register_reg64(brw, GEN7_SO_NUM_PRIMS_WRITTEN(i), HSW_CS_GPR(2));
BEGIN_BATCH(9);
OUT_BATCH(HSW_MI_MATH | (9 - 2));
/* GPR1 = GPR2 (End) - GPR1 (Start) */
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCA, R2));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCB, R1));
OUT_BATCH(MI_MATH_ALU0(SUB));
OUT_BATCH(MI_MATH_ALU2(STORE, R1, ACCU));
/* GPR0 = GPR0 (Tally) + GPR1 (Diff) */
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCA, R0));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCB, R1));
OUT_BATCH(MI_MATH_ALU0(ADD));
OUT_BATCH(MI_MATH_ALU2(STORE, R0, ACCU));
ADVANCE_BATCH();
}
if (!finalize) {
/* Write back the new tally */
brw_store_register_mem32(brw, obj->prim_count_bo, HSW_CS_GPR(0),
TALLY_OFFSET + i * sizeof(uint32_t));
} else {
/* Convert the number of primitives to the number of vertices. */
if (obj->primitive_mode == GL_LINES) {
/* Double R0 (R0 = R0 + R0) */
BEGIN_BATCH(5);
OUT_BATCH(HSW_MI_MATH | (5 - 2));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCA, R0));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCB, R0));
OUT_BATCH(MI_MATH_ALU0(ADD));
OUT_BATCH(MI_MATH_ALU2(STORE, R0, ACCU));
ADVANCE_BATCH();
} else if (obj->primitive_mode == GL_TRIANGLES) {
/* Triple R0 (R1 = R0 + R0, R0 = R0 + R1) */
BEGIN_BATCH(9);
OUT_BATCH(HSW_MI_MATH | (9 - 2));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCA, R0));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCB, R0));
OUT_BATCH(MI_MATH_ALU0(ADD));
OUT_BATCH(MI_MATH_ALU2(STORE, R1, ACCU));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCA, R0));
OUT_BATCH(MI_MATH_ALU2(LOAD, SRCB, R1));
OUT_BATCH(MI_MATH_ALU0(ADD));
OUT_BATCH(MI_MATH_ALU2(STORE, R0, ACCU));
ADVANCE_BATCH();
}
/* Store it to the final result */
brw_store_register_mem32(brw, obj->prim_count_bo, HSW_CS_GPR(0),
i * sizeof(uint32_t));
}
}
}
/**
* BeginTransformFeedback() driver hook.
*/
void
hsw_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
struct gl_transform_feedback_object *obj)
{
struct brw_context *brw = brw_context(ctx);
struct brw_transform_feedback_object *brw_obj =
(struct brw_transform_feedback_object *) obj;
brw_obj->primitive_mode = mode;
/* Reset the SO buffer offsets to 0. */
if (brw->gen >= 8) {
brw_obj->zero_offsets = true;
} else {
BEGIN_BATCH(1 + 2 * BRW_MAX_XFB_STREAMS);
OUT_BATCH(MI_LOAD_REGISTER_IMM | (1 + 2 * BRW_MAX_XFB_STREAMS - 2));
for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
OUT_BATCH(GEN7_SO_WRITE_OFFSET(i));
OUT_BATCH(0);
}
ADVANCE_BATCH();
}
/* Zero out the initial tallies */
brw_store_data_imm64(brw, brw_obj->prim_count_bo, TALLY_OFFSET, 0ull);
brw_store_data_imm64(brw, brw_obj->prim_count_bo, TALLY_OFFSET + 8, 0ull);
/* Store the new starting value of the SO_NUM_PRIMS_WRITTEN counters. */
save_prim_start_values(brw, brw_obj);
}
/**
* PauseTransformFeedback() driver hook.
*/
void
hsw_pause_transform_feedback(struct gl_context *ctx,
struct gl_transform_feedback_object *obj)
{
struct brw_context *brw = brw_context(ctx);
struct brw_transform_feedback_object *brw_obj =
(struct brw_transform_feedback_object *) obj;
if (brw->is_haswell) {
/* Flush any drawing so that the counters have the right values. */
brw_emit_mi_flush(brw);
/* Save the SOL buffer offset register values. */
for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
BEGIN_BATCH(3);
OUT_BATCH(MI_STORE_REGISTER_MEM | (3 - 2));
OUT_BATCH(GEN7_SO_WRITE_OFFSET(i));
OUT_RELOC(brw_obj->offset_bo,
I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
i * sizeof(uint32_t));
ADVANCE_BATCH();
}
}
/* Add any primitives written to our tally */
tally_prims_written(brw, brw_obj, false);
}
/**
* ResumeTransformFeedback() driver hook.
*/
void
hsw_resume_transform_feedback(struct gl_context *ctx,
struct gl_transform_feedback_object *obj)
{
struct brw_context *brw = brw_context(ctx);
struct brw_transform_feedback_object *brw_obj =
(struct brw_transform_feedback_object *) obj;
if (brw->is_haswell) {
/* Reload the SOL buffer offset registers. */
for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
BEGIN_BATCH(3);
OUT_BATCH(GEN7_MI_LOAD_REGISTER_MEM | (3 - 2));
OUT_BATCH(GEN7_SO_WRITE_OFFSET(i));
OUT_RELOC(brw_obj->offset_bo,
I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
i * sizeof(uint32_t));
ADVANCE_BATCH();
}
}
/* Store the new starting value of the SO_NUM_PRIMS_WRITTEN counters. */
save_prim_start_values(brw, brw_obj);
}
/**
* EndTransformFeedback() driver hook.
*/
void
hsw_end_transform_feedback(struct gl_context *ctx,
struct gl_transform_feedback_object *obj)
{
struct brw_context *brw = brw_context(ctx);
struct brw_transform_feedback_object *brw_obj =
(struct brw_transform_feedback_object *) obj;
/* Add any primitives written to our tally, convert it from the number
* of primitives written to the number of vertices written, and store
* it in the "final" location in the buffer which DrawTransformFeedback()
* will use as the vertex count.
*/
tally_prims_written(brw, brw_obj, true);
}
|
