1/*
2 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
3 Intel funded Tungsten Graphics (http://www.tungstengraphics.com) 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 <keith@tungstengraphics.com>
30  */
31
32
33
34#include "intel_batchbuffer.h"
35#include "brw_context.h"
36#include "brw_state.h"
37#include "brw_defines.h"
38
39#define VS 0
40#define GS 1
41#define CLP 2
42#define SF 3
43#define CS 4
44
45/** @file brw_urb.c
46 *
47 * Manages the division of the URB space between the various fixed-function
48 * units.
49 *
50 * See the Thread Initiation Management section of the GEN4 B-Spec, and
51 * the individual *_STATE structures for restrictions on numbers of
52 * entries and threads.
53 */
54
55/*
56 * Generally, a unit requires a min_nr_entries based on how many entries
57 * it produces before the downstream unit gets unblocked and can use and
58 * dereference some of its handles.
59 *
60 * The SF unit preallocates a PUE at the start of thread dispatch, and only
61 * uses that one.  So it requires one entry per thread.
62 *
63 * For CLIP, the SF unit will hold the previous primitive while the
64 * next is getting assembled, meaning that linestrips require 3 CLIP VUEs
65 * (vertices) to ensure continued processing, trifans require 4, and tristrips
66 * require 5.  There can be 1 or 2 threads, and each has the same requirement.
67 *
68 * GS has the same requirement as CLIP, but it never handles tristrips,
69 * so we can lower the minimum to 4 for the POLYGONs (trifans) it produces.
70 * We only run it single-threaded.
71 *
72 * For VS, the number of entries may be 8, 12, 16, or 32 (or 64 on G4X).
73 * Each thread processes 2 preallocated VUEs (vertices) at a time, and they
74 * get streamed down as soon as threads processing earlier vertices get
75 * theirs accepted.
76 *
77 * Each unit will take the number of URB entries we give it (based on the
78 * entry size calculated in brw_vs_emit.c for VUEs, brw_sf_emit.c for PUEs,
79 * and brw_curbe.c for the CURBEs) and decide its maximum number of
80 * threads it can support based on that. in brw_*_state.c.
81 *
82 * XXX: Are the min_entry_size numbers useful?
83 * XXX: Verify min_nr_entries, esp for VS.
84 * XXX: Verify SF min_entry_size.
85 */
86static const struct {
87   GLuint min_nr_entries;
88   GLuint preferred_nr_entries;
89   GLuint min_entry_size;
90   GLuint max_entry_size;
91} limits[CS+1] = {
92   { 16, 32, 1, 5 },			/* vs */
93   { 4, 8,  1, 5 },			/* gs */
94   { 5, 10,  1, 5 },			/* clp */
95   { 1, 8,  1, 12 },		        /* sf */
96   { 1, 4,  1, 32 }			/* cs */
97};
98
99
100static bool check_urb_layout(struct brw_context *brw)
101{
102   brw->urb.vs_start = 0;
103   brw->urb.gs_start = brw->urb.nr_vs_entries * brw->urb.vsize;
104   brw->urb.clip_start = brw->urb.gs_start + brw->urb.nr_gs_entries * brw->urb.vsize;
105   brw->urb.sf_start = brw->urb.clip_start + brw->urb.nr_clip_entries * brw->urb.vsize;
106   brw->urb.cs_start = brw->urb.sf_start + brw->urb.nr_sf_entries * brw->urb.sfsize;
107
108   return brw->urb.cs_start + brw->urb.nr_cs_entries *
109      brw->urb.csize <= brw->urb.size;
110}
111
112/* Most minimal update, forces re-emit of URB fence packet after GS
113 * unit turned on/off.
114 */
115static void recalculate_urb_fence( struct brw_context *brw )
116{
117   struct intel_context *intel = &brw->intel;
118   GLuint csize = brw->curbe.total_size;
119   GLuint vsize = brw->vs.prog_data->urb_entry_size;
120   GLuint sfsize = brw->sf.prog_data->urb_entry_size;
121
122   if (csize < limits[CS].min_entry_size)
123      csize = limits[CS].min_entry_size;
124
125   if (vsize < limits[VS].min_entry_size)
126      vsize = limits[VS].min_entry_size;
127
128   if (sfsize < limits[SF].min_entry_size)
129      sfsize = limits[SF].min_entry_size;
130
131   if (brw->urb.vsize < vsize ||
132       brw->urb.sfsize < sfsize ||
133       brw->urb.csize < csize ||
134       (brw->urb.constrained && (brw->urb.vsize > vsize ||
135				 brw->urb.sfsize > sfsize ||
136				 brw->urb.csize > csize))) {
137
138
139      brw->urb.csize = csize;
140      brw->urb.sfsize = sfsize;
141      brw->urb.vsize = vsize;
142
143      brw->urb.nr_vs_entries = limits[VS].preferred_nr_entries;
144      brw->urb.nr_gs_entries = limits[GS].preferred_nr_entries;
145      brw->urb.nr_clip_entries = limits[CLP].preferred_nr_entries;
146      brw->urb.nr_sf_entries = limits[SF].preferred_nr_entries;
147      brw->urb.nr_cs_entries = limits[CS].preferred_nr_entries;
148
149      brw->urb.constrained = 0;
150
151      if (intel->gen == 5) {
152         brw->urb.nr_vs_entries = 128;
153         brw->urb.nr_sf_entries = 48;
154         if (check_urb_layout(brw)) {
155            goto done;
156         } else {
157            brw->urb.constrained = 1;
158            brw->urb.nr_vs_entries = limits[VS].preferred_nr_entries;
159            brw->urb.nr_sf_entries = limits[SF].preferred_nr_entries;
160         }
161      } else if (intel->is_g4x) {
162	 brw->urb.nr_vs_entries = 64;
163	 if (check_urb_layout(brw)) {
164	    goto done;
165	 } else {
166	    brw->urb.constrained = 1;
167	    brw->urb.nr_vs_entries = limits[VS].preferred_nr_entries;
168	 }
169      }
170
171      if (!check_urb_layout(brw)) {
172	 brw->urb.nr_vs_entries = limits[VS].min_nr_entries;
173	 brw->urb.nr_gs_entries = limits[GS].min_nr_entries;
174	 brw->urb.nr_clip_entries = limits[CLP].min_nr_entries;
175	 brw->urb.nr_sf_entries = limits[SF].min_nr_entries;
176	 brw->urb.nr_cs_entries = limits[CS].min_nr_entries;
177
178	 /* Mark us as operating with constrained nr_entries, so that next
179	  * time we recalculate we'll resize the fences in the hope of
180	  * escaping constrained mode and getting back to normal performance.
181	  */
182	 brw->urb.constrained = 1;
183
184	 if (!check_urb_layout(brw)) {
185	    /* This is impossible, given the maximal sizes of urb
186	     * entries and the values for minimum nr of entries
187	     * provided above.
188	     */
189	    printf("couldn't calculate URB layout!\n");
190	    exit(1);
191	 }
192
193	 if (unlikely(INTEL_DEBUG & (DEBUG_URB|DEBUG_PERF)))
194	    printf("URB CONSTRAINED\n");
195      }
196
197done:
198      if (unlikely(INTEL_DEBUG & DEBUG_URB))
199	 printf("URB fence: %d ..VS.. %d ..GS.. %d ..CLP.. %d ..SF.. %d ..CS.. %d\n",
200		      brw->urb.vs_start,
201		      brw->urb.gs_start,
202		      brw->urb.clip_start,
203		      brw->urb.sf_start,
204		      brw->urb.cs_start,
205		      brw->urb.size);
206
207      brw->state.dirty.brw |= BRW_NEW_URB_FENCE;
208   }
209}
210
211
212const struct brw_tracked_state brw_recalculate_urb_fence = {
213   .dirty = {
214      .mesa = 0,
215      .brw = BRW_NEW_CURBE_OFFSETS,
216      .cache = (CACHE_NEW_VS_PROG |
217		CACHE_NEW_SF_PROG)
218   },
219   .emit = recalculate_urb_fence
220};
221
222
223
224
225
226void brw_upload_urb_fence(struct brw_context *brw)
227{
228   struct brw_urb_fence uf;
229   memset(&uf, 0, sizeof(uf));
230
231   uf.header.opcode = CMD_URB_FENCE;
232   uf.header.length = sizeof(uf)/4-2;
233   uf.header.vs_realloc = 1;
234   uf.header.gs_realloc = 1;
235   uf.header.clp_realloc = 1;
236   uf.header.sf_realloc = 1;
237   uf.header.vfe_realloc = 1;
238   uf.header.cs_realloc = 1;
239
240   /* The ordering below is correct, not the layout in the
241    * instruction.
242    *
243    * There are 256/384 urb reg pairs in total.
244    */
245   uf.bits0.vs_fence  = brw->urb.gs_start;
246   uf.bits0.gs_fence  = brw->urb.clip_start;
247   uf.bits0.clp_fence = brw->urb.sf_start;
248   uf.bits1.sf_fence  = brw->urb.cs_start;
249   uf.bits1.cs_fence  = brw->urb.size;
250
251   /* erratum: URB_FENCE must not cross a 64byte cacheline */
252   if ((brw->intel.batch.used & 15) > 12) {
253      int pad = 16 - (brw->intel.batch.used & 15);
254      do
255	 brw->intel.batch.map[brw->intel.batch.used++] = MI_NOOP;
256      while (--pad);
257   }
258
259   BRW_BATCH_STRUCT(brw, &uf);
260}
261