1 /*
2 Copyright (C) Intel Corp. 2006. All Rights Reserved.
3 Intel funded Tungsten Graphics to
4 develop this 3D driver.
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a copy of this software and associated documentation files (the
8 "Software"), to deal in the Software without restriction, including
9 without limitation the rights to use, copy, modify, merge, publish,
10 distribute, sublicense, and/or sell copies of the Software, and to
11 permit persons to whom the Software is furnished to do so, subject to
12 the following conditions:
13
14 The above copyright notice and this permission notice (including the
15 next paragraph) shall be included in all copies or substantial
16 portions of the Software.
17
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21 IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25
26 **********************************************************************/
27 /*
28 * Authors:
29 * Keith Whitwell <keithw@vmware.com>
30 */
31
32 /** @file brw_curbe.c
33 *
34 * Push constant handling for gen4/5.
35 *
36 * Push constants are constant values (such as GLSL uniforms) that are
37 * pre-loaded into a shader stage's register space at thread spawn time. On
38 * gen4 and gen5, we create a blob in memory containing all the push constants
39 * for all the stages in order. At CMD_CONST_BUFFER time that blob is loaded
40 * into URB space as a constant URB entry (CURBE) so that it can be accessed
41 * quickly at thread setup time. Each individual fixed function unit's state
42 * (brw_vs_state.c for example) tells the hardware which subset of the CURBE
43 * it wants in its register space, and we calculate those areas here under the
44 * BRW_NEW_PUSH_CONSTANT_ALLOCATION state flag. The brw_urb.c allocation will control
45 * how many CURBEs can be loaded into the hardware at once before a pipeline
46 * stall occurs at CMD_CONST_BUFFER time.
47 *
48 * On gen6+, constant handling becomes a much simpler set of per-unit state.
49 * See gen6_upload_vec4_push_constants() in gen6_vs_state.c for that code.
50 */
51
52
53 #include "compiler/nir/nir.h"
54 #include "main/context.h"
55 #include "main/macros.h"
56 #include "main/enums.h"
57 #include "program/prog_parameter.h"
58 #include "program/prog_print.h"
59 #include "program/prog_statevars.h"
60 #include "util/bitscan.h"
61 #include "intel_batchbuffer.h"
62 #include "intel_buffer_objects.h"
63 #include "brw_context.h"
64 #include "brw_defines.h"
65 #include "brw_state.h"
66 #include "brw_util.h"
67 #include "util/u_math.h"
68
69
70 /**
71 * Partition the CURBE between the various users of constant values.
72 *
73 * If the users all fit within the previous allocatation, we avoid changing
74 * the layout because that means reuploading all unit state and uploading new
75 * constant buffers.
76 */
calculate_curbe_offsets(struct brw_context * brw)77 static void calculate_curbe_offsets( struct brw_context *brw )
78 {
79 struct gl_context *ctx = &brw->ctx;
80 /* BRW_NEW_FS_PROG_DATA */
81 const GLuint nr_fp_regs = (brw->wm.base.prog_data->nr_params + 15) / 16;
82
83 /* BRW_NEW_VS_PROG_DATA */
84 const GLuint nr_vp_regs = (brw->vs.base.prog_data->nr_params + 15) / 16;
85 GLuint nr_clip_regs = 0;
86 GLuint total_regs;
87
88 /* _NEW_TRANSFORM */
89 if (ctx->Transform.ClipPlanesEnabled) {
90 GLuint nr_planes = 6 + util_bitcount(ctx->Transform.ClipPlanesEnabled);
91 nr_clip_regs = (nr_planes * 4 + 15) / 16;
92 }
93
94
95 total_regs = nr_fp_regs + nr_vp_regs + nr_clip_regs;
96
97 /* The CURBE allocation size is limited to 32 512-bit units (128 EU
98 * registers, or 1024 floats). See CS_URB_STATE in the gen4 or gen5
99 * (volume 1, part 1) PRMs.
100 *
101 * Note that in brw_fs.cpp we're only loading up to 16 EU registers of
102 * values as push constants before spilling to pull constants, and in
103 * brw_vec4.cpp we're loading up to 32 registers of push constants. An EU
104 * register is 1/2 of one of these URB entry units, so that leaves us 16 EU
105 * regs for clip.
106 */
107 assert(total_regs <= 32);
108
109 /* Lazy resize:
110 */
111 if (nr_fp_regs > brw->curbe.wm_size ||
112 nr_vp_regs > brw->curbe.vs_size ||
113 nr_clip_regs != brw->curbe.clip_size ||
114 (total_regs < brw->curbe.total_size / 4 &&
115 brw->curbe.total_size > 16)) {
116
117 GLuint reg = 0;
118
119 /* Calculate a new layout:
120 */
121 reg = 0;
122 brw->curbe.wm_start = reg;
123 brw->curbe.wm_size = nr_fp_regs; reg += nr_fp_regs;
124 brw->curbe.clip_start = reg;
125 brw->curbe.clip_size = nr_clip_regs; reg += nr_clip_regs;
126 brw->curbe.vs_start = reg;
127 brw->curbe.vs_size = nr_vp_regs; reg += nr_vp_regs;
128 brw->curbe.total_size = reg;
129
130 if (0)
131 fprintf(stderr, "curbe wm %d+%d clip %d+%d vs %d+%d\n",
132 brw->curbe.wm_start,
133 brw->curbe.wm_size,
134 brw->curbe.clip_start,
135 brw->curbe.clip_size,
136 brw->curbe.vs_start,
137 brw->curbe.vs_size );
138
139 brw->ctx.NewDriverState |= BRW_NEW_PUSH_CONSTANT_ALLOCATION;
140 }
141 }
142
143
144 const struct brw_tracked_state brw_curbe_offsets = {
145 .dirty = {
146 .mesa = _NEW_TRANSFORM,
147 .brw = BRW_NEW_CONTEXT |
148 BRW_NEW_BLORP |
149 BRW_NEW_FS_PROG_DATA |
150 BRW_NEW_VS_PROG_DATA,
151 },
152 .emit = calculate_curbe_offsets
153 };
154
155
156
157
158 /** Uploads the CS_URB_STATE packet.
159 *
160 * Just like brw_vs_state.c and brw_wm_state.c define a URB entry size and
161 * number of entries for their stages, constant buffers do so using this state
162 * packet. Having multiple CURBEs in the URB at the same time allows the
163 * hardware to avoid a pipeline stall between primitives using different
164 * constant buffer contents.
165 */
brw_upload_cs_urb_state(struct brw_context * brw)166 void brw_upload_cs_urb_state(struct brw_context *brw)
167 {
168 BEGIN_BATCH(2);
169 OUT_BATCH(CMD_CS_URB_STATE << 16 | (2-2));
170
171 /* BRW_NEW_URB_FENCE */
172 if (brw->urb.csize == 0) {
173 OUT_BATCH(0);
174 } else {
175 /* BRW_NEW_URB_FENCE */
176 assert(brw->urb.nr_cs_entries);
177 OUT_BATCH((brw->urb.csize - 1) << 4 | brw->urb.nr_cs_entries);
178 }
179 ADVANCE_BATCH();
180 }
181
182 static const GLfloat fixed_plane[6][4] = {
183 { 0, 0, -1, 1 },
184 { 0, 0, 1, 1 },
185 { 0, -1, 0, 1 },
186 { 0, 1, 0, 1 },
187 {-1, 0, 0, 1 },
188 { 1, 0, 0, 1 }
189 };
190
191 /**
192 * Gathers together all the uniform values into a block of memory to be
193 * uploaded into the CURBE, then emits the state packet telling the hardware
194 * the new location.
195 */
196 static void
brw_upload_constant_buffer(struct brw_context * brw)197 brw_upload_constant_buffer(struct brw_context *brw)
198 {
199 const struct gen_device_info *devinfo = &brw->screen->devinfo;
200 struct gl_context *ctx = &brw->ctx;
201 /* BRW_NEW_PUSH_CONSTANT_ALLOCATION */
202 const GLuint sz = brw->curbe.total_size;
203 const GLuint bufsz = sz * 16 * sizeof(GLfloat);
204 gl_constant_value *buf;
205 GLuint i;
206 gl_clip_plane *clip_planes;
207
208 /* BRW_NEW_FRAGMENT_PROGRAM */
209 struct gl_program *fp = brw->programs[MESA_SHADER_FRAGMENT];
210
211 /* BRW_NEW_VERTEX_PROGRAM */
212 struct gl_program *vp = brw->programs[MESA_SHADER_VERTEX];
213
214 if (sz == 0) {
215 goto emit;
216 }
217
218 buf = brw_upload_space(&brw->upload, bufsz, 64,
219 &brw->curbe.curbe_bo, &brw->curbe.curbe_offset);
220
221 STATIC_ASSERT(sizeof(gl_constant_value) == sizeof(float));
222
223 /* fragment shader constants */
224 if (brw->curbe.wm_size) {
225 _mesa_load_state_parameters(ctx, fp->Parameters);
226
227 /* BRW_NEW_PUSH_CONSTANT_ALLOCATION */
228 GLuint offset = brw->curbe.wm_start * 16;
229
230 /* BRW_NEW_FS_PROG_DATA | _NEW_PROGRAM_CONSTANTS: copy uniform values */
231 brw_populate_constant_data(brw, fp, &brw->wm.base, &buf[offset],
232 brw->wm.base.prog_data->param,
233 brw->wm.base.prog_data->nr_params);
234 }
235
236 /* clipper constants */
237 if (brw->curbe.clip_size) {
238 GLuint offset = brw->curbe.clip_start * 16;
239 GLbitfield mask;
240
241 /* If any planes are going this way, send them all this way:
242 */
243 for (i = 0; i < 6; i++) {
244 buf[offset + i * 4 + 0].f = fixed_plane[i][0];
245 buf[offset + i * 4 + 1].f = fixed_plane[i][1];
246 buf[offset + i * 4 + 2].f = fixed_plane[i][2];
247 buf[offset + i * 4 + 3].f = fixed_plane[i][3];
248 }
249
250 /* Clip planes: _NEW_TRANSFORM plus _NEW_PROJECTION to get to
251 * clip-space:
252 */
253 clip_planes = brw_select_clip_planes(ctx);
254 mask = ctx->Transform.ClipPlanesEnabled;
255 while (mask) {
256 const int j = u_bit_scan(&mask);
257 buf[offset + i * 4 + 0].f = clip_planes[j][0];
258 buf[offset + i * 4 + 1].f = clip_planes[j][1];
259 buf[offset + i * 4 + 2].f = clip_planes[j][2];
260 buf[offset + i * 4 + 3].f = clip_planes[j][3];
261 i++;
262 }
263 }
264
265 /* vertex shader constants */
266 if (brw->curbe.vs_size) {
267 _mesa_load_state_parameters(ctx, vp->Parameters);
268
269 GLuint offset = brw->curbe.vs_start * 16;
270
271 /* BRW_NEW_VS_PROG_DATA | _NEW_PROGRAM_CONSTANTS: copy uniform values */
272 brw_populate_constant_data(brw, vp, &brw->vs.base, &buf[offset],
273 brw->vs.base.prog_data->param,
274 brw->vs.base.prog_data->nr_params);
275 }
276
277 if (0) {
278 for (i = 0; i < sz*16; i+=4)
279 fprintf(stderr, "curbe %d.%d: %f %f %f %f\n", i/8, i&4,
280 buf[i+0].f, buf[i+1].f, buf[i+2].f, buf[i+3].f);
281 }
282
283 /* Because this provokes an action (ie copy the constants into the
284 * URB), it shouldn't be shortcircuited if identical to the
285 * previous time - because eg. the urb destination may have
286 * changed, or the urb contents different to last time.
287 *
288 * Note that the data referred to is actually copied internally,
289 * not just used in place according to passed pointer.
290 *
291 * It appears that the CS unit takes care of using each available
292 * URB entry (Const URB Entry == CURBE) in turn, and issuing
293 * flushes as necessary when doublebuffering of CURBEs isn't
294 * possible.
295 */
296
297 emit:
298 /* BRW_NEW_URB_FENCE: From the gen4 PRM, volume 1, section 3.9.8
299 * (CONSTANT_BUFFER (CURBE Load)):
300 *
301 * "Modifying the CS URB allocation via URB_FENCE invalidates any
302 * previous CURBE entries. Therefore software must subsequently
303 * [re]issue a CONSTANT_BUFFER command before CURBE data can be used
304 * in the pipeline."
305 */
306 BEGIN_BATCH(2);
307 if (brw->curbe.total_size == 0) {
308 OUT_BATCH((CMD_CONST_BUFFER << 16) | (2 - 2));
309 OUT_BATCH(0);
310 } else {
311 OUT_BATCH((CMD_CONST_BUFFER << 16) | (1 << 8) | (2 - 2));
312 OUT_RELOC(brw->curbe.curbe_bo, 0,
313 (brw->curbe.total_size - 1) + brw->curbe.curbe_offset);
314 }
315 ADVANCE_BATCH();
316
317 /* Work around a Broadwater/Crestline depth interpolator bug. The
318 * following sequence will cause GPU hangs:
319 *
320 * 1. Change state so that all depth related fields in CC_STATE are
321 * disabled, and in WM_STATE, only "PS Use Source Depth" is enabled.
322 * 2. Emit a CONSTANT_BUFFER packet.
323 * 3. Draw via 3DPRIMITIVE.
324 *
325 * The recommended workaround is to emit a non-pipelined state change after
326 * emitting CONSTANT_BUFFER, in order to drain the windowizer pipeline.
327 *
328 * We arbitrarily choose 3DSTATE_GLOBAL_DEPTH_CLAMP_OFFSET (as it's small),
329 * and always emit it when "PS Use Source Depth" is set. We could be more
330 * precise, but the additional complexity is probably not worth it.
331 *
332 * BRW_NEW_FRAGMENT_PROGRAM
333 */
334 if (devinfo->gen == 4 && !devinfo->is_g4x &&
335 BITSET_TEST(fp->info.system_values_read, SYSTEM_VALUE_FRAG_COORD)) {
336 BEGIN_BATCH(2);
337 OUT_BATCH(_3DSTATE_GLOBAL_DEPTH_OFFSET_CLAMP << 16 | (2 - 2));
338 OUT_BATCH(0);
339 ADVANCE_BATCH();
340 }
341 }
342
343 const struct brw_tracked_state brw_constant_buffer = {
344 .dirty = {
345 .mesa = _NEW_PROGRAM_CONSTANTS,
346 .brw = BRW_NEW_BATCH |
347 BRW_NEW_BLORP |
348 BRW_NEW_PUSH_CONSTANT_ALLOCATION |
349 BRW_NEW_FRAGMENT_PROGRAM |
350 BRW_NEW_FS_PROG_DATA |
351 BRW_NEW_PSP | /* Implicit - hardware requires this, not used above */
352 BRW_NEW_URB_FENCE |
353 BRW_NEW_VS_PROG_DATA,
354 },
355 .emit = brw_upload_constant_buffer,
356 };
357