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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 #include "main/macros.h"
25 #include "intel_batchbuffer.h"
26 #include "brw_context.h"
27 #include "brw_state.h"
28 #include "brw_defines.h"
29 
30 #include "common/gen_l3_config.h"
31 
32 /**
33  * The following diagram shows how we partition the URB:
34  *
35  *        16kB or 32kB               Rest of the URB space
36  *   __________-__________   _________________-_________________
37  *  /                     \ /                                   \
38  * +-------------------------------------------------------------+
39  * |  VS/HS/DS/GS/FS Push  |           VS/HS/DS/GS URB           |
40  * |       Constants       |               Entries               |
41  * +-------------------------------------------------------------+
42  *
43  * Notably, push constants must be stored at the beginning of the URB
44  * space, while entries can be stored anywhere.  Ivybridge and Haswell
45  * GT1/GT2 have a maximum constant buffer size of 16kB, while Haswell GT3
46  * doubles this (32kB).
47  *
48  * Ivybridge and Haswell GT1/GT2 allow push constants to be located (and
49  * sized) in increments of 1kB.  Haswell GT3 requires them to be located and
50  * sized in increments of 2kB.
51  *
52  * Currently we split the constant buffer space evenly among whatever stages
53  * are active.  This is probably not ideal, but simple.
54  *
55  * Ivybridge GT1 and Haswell GT1 have 128kB of URB space.
56  * Ivybridge GT2 and Haswell GT2 have 256kB of URB space.
57  * Haswell GT3 has 512kB of URB space.
58  *
59  * See "Volume 2a: 3D Pipeline," section 1.8, "Volume 1b: Configurations",
60  * and the documentation for 3DSTATE_PUSH_CONSTANT_ALLOC_xS.
61  */
62 static void
gen7_allocate_push_constants(struct brw_context * brw)63 gen7_allocate_push_constants(struct brw_context *brw)
64 {
65    const struct gen_device_info *devinfo = &brw->screen->devinfo;
66 
67    /* BRW_NEW_GEOMETRY_PROGRAM */
68    bool gs_present = brw->programs[MESA_SHADER_GEOMETRY];
69 
70    /* BRW_NEW_TESS_PROGRAMS */
71    bool tess_present = brw->programs[MESA_SHADER_TESS_EVAL];
72 
73    unsigned avail_size = 16;
74    unsigned multiplier =
75       (devinfo->gen >= 8 || (devinfo->is_haswell && devinfo->gt == 3)) ? 2 : 1;
76 
77    int stages = 2 + gs_present + 2 * tess_present;
78 
79    /* Divide up the available space equally between stages.  Because we
80     * round down (using floor division), there may be some left over
81     * space.  We allocate that to the pixel shader stage.
82     */
83    unsigned size_per_stage = avail_size / stages;
84 
85    unsigned vs_size = size_per_stage;
86    unsigned hs_size = tess_present ? size_per_stage : 0;
87    unsigned ds_size = tess_present ? size_per_stage : 0;
88    unsigned gs_size = gs_present ? size_per_stage : 0;
89    unsigned fs_size = avail_size - size_per_stage * (stages - 1);
90 
91    gen7_emit_push_constant_state(brw, multiplier * vs_size,
92                                  multiplier * hs_size, multiplier * ds_size,
93                                  multiplier * gs_size, multiplier * fs_size);
94 
95    /* From p115 of the Ivy Bridge PRM (3.2.1.4 3DSTATE_PUSH_CONSTANT_ALLOC_VS):
96     *
97     *     Programming Restriction:
98     *
99     *     The 3DSTATE_CONSTANT_VS must be reprogrammed prior to the next
100     *     3DPRIMITIVE command after programming the
101     *     3DSTATE_PUSH_CONSTANT_ALLOC_VS.
102     *
103     * Similar text exists for the other 3DSTATE_PUSH_CONSTANT_ALLOC_*
104     * commands.
105     */
106    brw->vs.base.push_constants_dirty = true;
107    brw->tcs.base.push_constants_dirty = true;
108    brw->tes.base.push_constants_dirty = true;
109    brw->gs.base.push_constants_dirty = true;
110    brw->wm.base.push_constants_dirty = true;
111 }
112 
113 void
gen7_emit_push_constant_state(struct brw_context * brw,unsigned vs_size,unsigned hs_size,unsigned ds_size,unsigned gs_size,unsigned fs_size)114 gen7_emit_push_constant_state(struct brw_context *brw, unsigned vs_size,
115                               unsigned hs_size, unsigned ds_size,
116                               unsigned gs_size, unsigned fs_size)
117 {
118    const struct gen_device_info *devinfo = &brw->screen->devinfo;
119    unsigned offset = 0;
120 
121    /* From the SKL PRM, Workarounds section (#878):
122     *
123     *    Push constant buffer corruption possible. WA: Insert 2 zero-length
124     *    PushConst_PS before every intended PushConst_PS update, issue a
125     *    NULLPRIM after each of the zero len PC update to make sure CS commits
126     *    them.
127     *
128     * This workaround is attempting to solve a pixel shader push constant
129     * synchronization issue.
130     *
131     * There's an unpublished WA that involves re-emitting
132     * 3DSTATE_PUSH_CONSTANT_ALLOC_PS for every 500-ish 3DSTATE_CONSTANT_PS
133     * packets. Since our counting methods may not be reliable due to
134     * context-switching and pre-emption, we instead choose to approximate this
135     * behavior by re-emitting the packet at the top of the batch.
136     */
137    if (brw->ctx.NewDriverState == BRW_NEW_BATCH) {
138        /* SKL GT2 and GLK 2x6 have reliably demonstrated this issue thus far.
139         * We've also seen some intermittent failures from SKL GT4 and BXT in
140         * the past.
141         */
142       if (!devinfo->is_skylake &&
143           !devinfo->is_broxton &&
144           !devinfo->is_geminilake)
145          return;
146    }
147 
148    BEGIN_BATCH(10);
149    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_VS << 16 | (2 - 2));
150    OUT_BATCH(vs_size | offset << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
151    offset += vs_size;
152 
153    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_HS << 16 | (2 - 2));
154    OUT_BATCH(hs_size | offset << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
155    offset += hs_size;
156 
157    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_DS << 16 | (2 - 2));
158    OUT_BATCH(ds_size | offset << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
159    offset += ds_size;
160 
161    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_GS << 16 | (2 - 2));
162    OUT_BATCH(gs_size | offset << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
163    offset += gs_size;
164 
165    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_PS << 16 | (2 - 2));
166    OUT_BATCH(fs_size | offset << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
167    ADVANCE_BATCH();
168 
169    /* From p292 of the Ivy Bridge PRM (11.2.4 3DSTATE_PUSH_CONSTANT_ALLOC_PS):
170     *
171     *     A PIPE_CONTROL command with the CS Stall bit set must be programmed
172     *     in the ring after this instruction.
173     *
174     * No such restriction exists for Haswell or Baytrail.
175     */
176    if (devinfo->gen < 8 && !devinfo->is_haswell && !devinfo->is_baytrail)
177       gen7_emit_cs_stall_flush(brw);
178 }
179 
180 const struct brw_tracked_state gen7_push_constant_space = {
181    .dirty = {
182       .mesa = 0,
183       .brw = BRW_NEW_CONTEXT |
184              BRW_NEW_BATCH | /* Push constant workaround */
185              BRW_NEW_GEOMETRY_PROGRAM |
186              BRW_NEW_TESS_PROGRAMS,
187    },
188    .emit = gen7_allocate_push_constants,
189 };
190 
191 static void
upload_urb(struct brw_context * brw)192 upload_urb(struct brw_context *brw)
193 {
194    /* BRW_NEW_VS_PROG_DATA */
195    const struct brw_vue_prog_data *vs_vue_prog_data =
196       brw_vue_prog_data(brw->vs.base.prog_data);
197    const unsigned vs_size = MAX2(vs_vue_prog_data->urb_entry_size, 1);
198    /* BRW_NEW_GS_PROG_DATA */
199    const bool gs_present = brw->gs.base.prog_data;
200    /* BRW_NEW_TES_PROG_DATA */
201    const bool tess_present = brw->tes.base.prog_data;
202 
203    gen7_upload_urb(brw, vs_size, gs_present, tess_present);
204 }
205 
206 void
gen7_upload_urb(struct brw_context * brw,unsigned vs_size,bool gs_present,bool tess_present)207 gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
208                 bool gs_present, bool tess_present)
209 {
210    const struct gen_device_info *devinfo = &brw->screen->devinfo;
211 
212    /* BRW_NEW_{VS,TCS,TES,GS}_PROG_DATA */
213    struct brw_vue_prog_data *prog_data[4] = {
214       [MESA_SHADER_VERTEX] =
215          brw_vue_prog_data(brw->vs.base.prog_data),
216       [MESA_SHADER_TESS_CTRL] =
217          tess_present ? brw_vue_prog_data(brw->tcs.base.prog_data) : NULL,
218       [MESA_SHADER_TESS_EVAL] =
219          tess_present ? brw_vue_prog_data(brw->tes.base.prog_data) : NULL,
220       [MESA_SHADER_GEOMETRY] =
221          gs_present ? brw_vue_prog_data(brw->gs.base.prog_data) : NULL,
222    };
223 
224    unsigned entry_size[4];
225    entry_size[MESA_SHADER_VERTEX] = vs_size;
226    for (int i = MESA_SHADER_TESS_CTRL; i <= MESA_SHADER_GEOMETRY; i++) {
227       entry_size[i] = prog_data[i] ? prog_data[i]->urb_entry_size : 1;
228    }
229 
230    /* If we're just switching between programs with the same URB requirements,
231     * skip the rest of the logic.
232     */
233    if (brw->urb.vsize == entry_size[MESA_SHADER_VERTEX] &&
234        brw->urb.gs_present == gs_present &&
235        brw->urb.gsize == entry_size[MESA_SHADER_GEOMETRY] &&
236        brw->urb.tess_present == tess_present &&
237        brw->urb.hsize == entry_size[MESA_SHADER_TESS_CTRL] &&
238        brw->urb.dsize == entry_size[MESA_SHADER_TESS_EVAL]) {
239       return;
240    }
241    brw->urb.vsize = entry_size[MESA_SHADER_VERTEX];
242    brw->urb.gs_present = gs_present;
243    brw->urb.gsize = entry_size[MESA_SHADER_GEOMETRY];
244    brw->urb.tess_present = tess_present;
245    brw->urb.hsize = entry_size[MESA_SHADER_TESS_CTRL];
246    brw->urb.dsize = entry_size[MESA_SHADER_TESS_EVAL];
247 
248    unsigned entries[4];
249    unsigned start[4];
250    gen_get_urb_config(devinfo, brw->l3.config,
251                       tess_present, gs_present, entry_size,
252                       entries, start, NULL);
253 
254    if (devinfo->gen == 7 && !devinfo->is_haswell && !devinfo->is_baytrail)
255       gen7_emit_vs_workaround_flush(brw);
256 
257    BEGIN_BATCH(8);
258    for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
259       assert(devinfo->gen != 10 || entry_size[i] % 3);
260       OUT_BATCH((_3DSTATE_URB_VS + i) << 16 | (2 - 2));
261       OUT_BATCH(entries[i] |
262                 ((entry_size[i] - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
263                 (start[i] << GEN7_URB_STARTING_ADDRESS_SHIFT));
264    }
265    ADVANCE_BATCH();
266 }
267 
268 const struct brw_tracked_state gen7_urb = {
269    .dirty = {
270       .mesa = 0,
271       .brw = BRW_NEW_BLORP |
272              BRW_NEW_CONTEXT |
273              BRW_NEW_URB_SIZE |
274              BRW_NEW_GS_PROG_DATA |
275              BRW_NEW_TCS_PROG_DATA |
276              BRW_NEW_TES_PROG_DATA |
277              BRW_NEW_VS_PROG_DATA,
278    },
279    .emit = upload_urb,
280 };
281