1 /*
2 * Copyright © 2011 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 /**
25 * @file gen7_sol_state.c
26 *
27 * Controls the stream output logic (SOL) stage of the gen7 hardware, which is
28 * used to implement GL_EXT_transform_feedback.
29 */
30
31 #include "brw_context.h"
32 #include "brw_state.h"
33 #include "brw_defines.h"
34 #include "intel_batchbuffer.h"
35 #include "intel_buffer_objects.h"
36 #include "main/transformfeedback.h"
37
38 void
gen7_begin_transform_feedback(struct gl_context * ctx,GLenum mode,struct gl_transform_feedback_object * obj)39 gen7_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
40 struct gl_transform_feedback_object *obj)
41 {
42 struct brw_context *brw = brw_context(ctx);
43 struct brw_transform_feedback_object *brw_obj =
44 (struct brw_transform_feedback_object *) obj;
45
46 assert(brw->screen->devinfo.gen == 7);
47
48 /* Store the starting value of the SO_NUM_PRIMS_WRITTEN counters. */
49 brw_save_primitives_written_counters(brw, brw_obj);
50
51 /* Reset the SO buffer offsets to 0. */
52 if (!can_do_pipelined_register_writes(brw->screen)) {
53 intel_batchbuffer_flush(brw);
54 brw->batch.needs_sol_reset = true;
55 } else {
56 for (int i = 0; i < 4; i++) {
57 brw_load_register_imm32(brw, GEN7_SO_WRITE_OFFSET(i), 0);
58 }
59 }
60
61 brw_obj->primitive_mode = mode;
62 }
63
64 void
gen7_end_transform_feedback(struct gl_context * ctx,struct gl_transform_feedback_object * obj)65 gen7_end_transform_feedback(struct gl_context *ctx,
66 struct gl_transform_feedback_object *obj)
67 {
68 /* After EndTransformFeedback, it's likely that the client program will try
69 * to draw using the contents of the transform feedback buffer as vertex
70 * input. In order for this to work, we need to flush the data through at
71 * least the GS stage of the pipeline, and flush out the render cache. For
72 * simplicity, just do a full flush.
73 */
74 struct brw_context *brw = brw_context(ctx);
75 struct brw_transform_feedback_object *brw_obj =
76 (struct brw_transform_feedback_object *) obj;
77
78 /* Store the ending value of the SO_NUM_PRIMS_WRITTEN counters. */
79 if (!obj->Paused)
80 brw_save_primitives_written_counters(brw, brw_obj);
81
82 /* We've reached the end of a transform feedback begin/end block. This
83 * means that future DrawTransformFeedback() calls will need to pick up the
84 * results of the current counter, and that it's time to roll back the
85 * current primitive counter to zero.
86 */
87 brw_obj->previous_counter = brw_obj->counter;
88 brw_reset_transform_feedback_counter(&brw_obj->counter);
89
90 /* EndTransformFeedback() means that we need to update the number of
91 * vertices written. Since it's only necessary if DrawTransformFeedback()
92 * is called and it means mapping a buffer object, we delay computing it
93 * until it's absolutely necessary to try and avoid stalls.
94 */
95 brw_obj->vertices_written_valid = false;
96 }
97
98 void
gen7_pause_transform_feedback(struct gl_context * ctx,struct gl_transform_feedback_object * obj)99 gen7_pause_transform_feedback(struct gl_context *ctx,
100 struct gl_transform_feedback_object *obj)
101 {
102 struct brw_context *brw = brw_context(ctx);
103 struct brw_transform_feedback_object *brw_obj =
104 (struct brw_transform_feedback_object *) obj;
105
106 /* Flush any drawing so that the counters have the right values. */
107 brw_emit_mi_flush(brw);
108
109 assert(brw->screen->devinfo.gen == 7);
110
111 /* Save the SOL buffer offset register values. */
112 for (int i = 0; i < 4; i++) {
113 BEGIN_BATCH(3);
114 OUT_BATCH(MI_STORE_REGISTER_MEM | (3 - 2));
115 OUT_BATCH(GEN7_SO_WRITE_OFFSET(i));
116 OUT_RELOC(brw_obj->offset_bo, RELOC_WRITE, i * sizeof(uint32_t));
117 ADVANCE_BATCH();
118 }
119
120 /* Store the temporary ending value of the SO_NUM_PRIMS_WRITTEN counters.
121 * While this operation is paused, other transform feedback actions may
122 * occur, which will contribute to the counters. We need to exclude that
123 * from our counts.
124 */
125 brw_save_primitives_written_counters(brw, brw_obj);
126 }
127
128 void
gen7_resume_transform_feedback(struct gl_context * ctx,struct gl_transform_feedback_object * obj)129 gen7_resume_transform_feedback(struct gl_context *ctx,
130 struct gl_transform_feedback_object *obj)
131 {
132 struct brw_context *brw = brw_context(ctx);
133 struct brw_transform_feedback_object *brw_obj =
134 (struct brw_transform_feedback_object *) obj;
135
136 assert(brw->screen->devinfo.gen == 7);
137
138 /* Reload the SOL buffer offset registers. */
139 for (int i = 0; i < 4; i++) {
140 BEGIN_BATCH(3);
141 OUT_BATCH(GEN7_MI_LOAD_REGISTER_MEM | (3 - 2));
142 OUT_BATCH(GEN7_SO_WRITE_OFFSET(i));
143 OUT_RELOC(brw_obj->offset_bo, RELOC_WRITE, i * sizeof(uint32_t));
144 ADVANCE_BATCH();
145 }
146
147 /* Store the new starting value of the SO_NUM_PRIMS_WRITTEN counters. */
148 brw_save_primitives_written_counters(brw, brw_obj);
149 }
150