1 /*
2 * Copyright © 2022 Google, Inc.
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 FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 */
23
24 #include "nir.h"
25 #include "nir_builder.h"
26
27 #include "ir3/ir3_descriptor.h"
28
29 static bool
lower_intrinsic(nir_builder * b,nir_intrinsic_instr * intr)30 lower_intrinsic(nir_builder *b, nir_intrinsic_instr *intr)
31 {
32 unsigned desc_offset;
33
34 switch (intr->intrinsic) {
35 case nir_intrinsic_load_ssbo:
36 case nir_intrinsic_store_ssbo:
37 case nir_intrinsic_ssbo_atomic:
38 case nir_intrinsic_ssbo_atomic_swap:
39 case nir_intrinsic_get_ssbo_size:
40 desc_offset = IR3_BINDLESS_SSBO_OFFSET;
41 break;
42 case nir_intrinsic_image_load:
43 case nir_intrinsic_image_store:
44 case nir_intrinsic_image_atomic:
45 case nir_intrinsic_image_atomic_swap:
46 case nir_intrinsic_image_size:
47 case nir_intrinsic_image_samples:
48 desc_offset = IR3_BINDLESS_IMAGE_OFFSET;
49 break;
50 default:
51 return false;
52 }
53
54 unsigned buffer_src;
55 if (intr->intrinsic == nir_intrinsic_store_ssbo) {
56 /* store_ssbo has the value first, and ssbo src as 2nd src: */
57 buffer_src = 1;
58 } else {
59 /* the rest have ssbo src as 1st src: */
60 buffer_src = 0;
61 }
62
63 unsigned set = ir3_shader_descriptor_set(b->shader->info.stage);
64 nir_def *src = intr->src[buffer_src].ssa;
65 src = nir_iadd_imm(b, src, desc_offset);
66 /* An out-of-bounds index into an SSBO/image array can cause a GPU fault
67 * on access to the descriptor (I don't see any hw mechanism to bound the
68 * access). We could just allow the resulting iova fault (it is a read
69 * fault, so shouldn't corrupt anything), but at the cost of one extra
70 * instruction (as long as IR3_BINDLESS_DESC_COUNT is a power-of-two) we
71 * can avoid the dmesg spam and users thinking this is a driver bug:
72 */
73 src = nir_umod_imm(b, src, IR3_BINDLESS_DESC_COUNT);
74 nir_def *bindless = nir_bindless_resource_ir3(b, 32, src, set);
75 nir_src_rewrite(&intr->src[buffer_src], bindless);
76
77 return true;
78 }
79
80 static bool
lower_instr(nir_builder * b,nir_instr * instr,void * cb_data)81 lower_instr(nir_builder *b, nir_instr *instr, void *cb_data)
82 {
83 b->cursor = nir_before_instr(instr);
84 switch (instr->type) {
85 case nir_instr_type_intrinsic:
86 return lower_intrinsic(b, nir_instr_as_intrinsic(instr));
87 default:
88 return false;
89 }
90 }
91
92 /**
93 * Lower bindful image/SSBO to bindless
94 */
95 bool
ir3_nir_lower_io_to_bindless(nir_shader * shader)96 ir3_nir_lower_io_to_bindless(nir_shader *shader)
97 {
98 /* Note: We don't currently support API level bindless, as we assume we
99 * can remap bindful images/SSBOs to bindless while controlling the entire
100 * descriptor set space.
101 *
102 * If we needed to support API level bindless, we could probably just remap
103 * bindful ops to a range of the descriptor set space that does not conflict
104 * with what we advertise for bindless descriptors? But I'm not sure that
105 * ARB_bindless_texture is of too much value to care about, especially for
106 * GLES
107 */
108 assert(!shader->info.uses_bindless);
109
110 return nir_shader_instructions_pass(shader, lower_instr, nir_metadata_none, NULL);
111 }
112