1/*
2 * Copyright © 2014 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 * Authors:
24 *    Neil Roberts <neil@linux.intel.com>
25 */
26
27/** @file brw_conditional_render.c
28 *
29 * Support for conditional rendering based on query objects
30 * (GL_NV_conditional_render, GL_ARB_conditional_render_inverted) on Gen7+.
31 */
32
33#include "main/imports.h"
34#include "main/condrender.h"
35
36#include "brw_context.h"
37#include "brw_defines.h"
38#include "intel_batchbuffer.h"
39
40static void
41set_predicate_enable(struct brw_context *brw,
42                     bool value)
43{
44   if (value)
45      brw->predicate.state = BRW_PREDICATE_STATE_RENDER;
46   else
47      brw->predicate.state = BRW_PREDICATE_STATE_DONT_RENDER;
48}
49
50static void
51set_predicate_for_overflow_query(struct brw_context *brw,
52                                 struct brw_query_object *query,
53                                 int stream_start, int count)
54{
55   if (!can_do_mi_math_and_lrr(brw->screen)) {
56      brw->predicate.state = BRW_PREDICATE_STATE_STALL_FOR_QUERY;
57      return;
58   }
59
60   brw->predicate.state = BRW_PREDICATE_STATE_USE_BIT;
61
62   /* Needed to ensure the memory is coherent for the MI_LOAD_REGISTER_MEM
63    * command when loading the values into the predicate source registers for
64    * conditional rendering.
65    */
66   brw_emit_pipe_control_flush(brw, PIPE_CONTROL_FLUSH_ENABLE);
67
68   hsw_overflow_result_to_gpr0(brw, query, count);
69   brw_load_register_reg64(brw, MI_PREDICATE_SRC0, HSW_CS_GPR(0));
70   brw_load_register_imm64(brw, MI_PREDICATE_SRC1, 0ull);
71}
72
73static void
74set_predicate_for_occlusion_query(struct brw_context *brw,
75                                  struct brw_query_object *query)
76{
77   if (!brw->predicate.supported) {
78      brw->predicate.state = BRW_PREDICATE_STATE_STALL_FOR_QUERY;
79      return;
80   }
81
82   brw->predicate.state = BRW_PREDICATE_STATE_USE_BIT;
83
84   /* Needed to ensure the memory is coherent for the MI_LOAD_REGISTER_MEM
85    * command when loading the values into the predicate source registers for
86    * conditional rendering.
87    */
88   brw_emit_pipe_control_flush(brw, PIPE_CONTROL_FLUSH_ENABLE);
89
90   brw_load_register_mem64(brw, MI_PREDICATE_SRC0, query->bo, 0 /* offset */);
91   brw_load_register_mem64(brw, MI_PREDICATE_SRC1, query->bo, 8 /* offset */);
92}
93
94static void
95set_predicate_for_result(struct brw_context *brw,
96                         struct brw_query_object *query,
97                         bool inverted)
98{
99   int load_op;
100
101   assert(query->bo != NULL);
102
103   switch (query->Base.Target) {
104   case GL_TRANSFORM_FEEDBACK_STREAM_OVERFLOW_ARB:
105      set_predicate_for_overflow_query(brw, query, 0, 1);
106      break;
107   case GL_TRANSFORM_FEEDBACK_OVERFLOW_ARB:
108      set_predicate_for_overflow_query(brw, query, 0, MAX_VERTEX_STREAMS);
109      break;
110   default:
111      set_predicate_for_occlusion_query(brw, query);
112   }
113
114   if (brw->predicate.state == BRW_PREDICATE_STATE_USE_BIT) {
115      if (inverted)
116         load_op = MI_PREDICATE_LOADOP_LOAD;
117      else
118         load_op = MI_PREDICATE_LOADOP_LOADINV;
119
120      BEGIN_BATCH(1);
121      OUT_BATCH(GEN7_MI_PREDICATE |
122                load_op |
123                MI_PREDICATE_COMBINEOP_SET |
124                MI_PREDICATE_COMPAREOP_SRCS_EQUAL);
125      ADVANCE_BATCH();
126   }
127}
128
129static void
130brw_begin_conditional_render(struct gl_context *ctx,
131                             struct gl_query_object *q,
132                             GLenum mode)
133{
134   struct brw_context *brw = brw_context(ctx);
135   struct brw_query_object *query = (struct brw_query_object *) q;
136   bool inverted;
137
138   switch (mode) {
139   case GL_QUERY_WAIT:
140   case GL_QUERY_NO_WAIT:
141   case GL_QUERY_BY_REGION_WAIT:
142   case GL_QUERY_BY_REGION_NO_WAIT:
143      inverted = false;
144      break;
145   case GL_QUERY_WAIT_INVERTED:
146   case GL_QUERY_NO_WAIT_INVERTED:
147   case GL_QUERY_BY_REGION_WAIT_INVERTED:
148   case GL_QUERY_BY_REGION_NO_WAIT_INVERTED:
149      inverted = true;
150      break;
151   default:
152      unreachable("Unexpected conditional render mode");
153   }
154
155   /* If there are already samples from a BLT operation or if the query object
156    * is ready then we can avoid looking at the values in the buffer and just
157    * decide whether to draw using the CPU without stalling.
158    */
159   if (query->Base.Result || query->Base.Ready)
160      set_predicate_enable(brw, (query->Base.Result != 0) ^ inverted);
161   else
162      set_predicate_for_result(brw, query, inverted);
163}
164
165static void
166brw_end_conditional_render(struct gl_context *ctx,
167                           struct gl_query_object *q)
168{
169   struct brw_context *brw = brw_context(ctx);
170
171   /* When there is no longer a conditional render in progress it should
172    * always render.
173    */
174   brw->predicate.state = BRW_PREDICATE_STATE_RENDER;
175}
176
177void
178brw_init_conditional_render_functions(struct dd_function_table *functions)
179{
180   functions->BeginConditionalRender = brw_begin_conditional_render;
181   functions->EndConditionalRender = brw_end_conditional_render;
182}
183
184bool
185brw_check_conditional_render(struct brw_context *brw)
186{
187   if (brw->predicate.state == BRW_PREDICATE_STATE_STALL_FOR_QUERY) {
188      perf_debug("Conditional rendering is implemented in software and may "
189                 "stall.\n");
190      return _mesa_check_conditional_render(&brw->ctx);
191   }
192
193   return brw->predicate.state != BRW_PREDICATE_STATE_DONT_RENDER;
194}
195