1 /*
2  * Copyright (C) 2019-2020 Collabora, Ltd.
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 #ifndef __BI_QUIRKS_H
25 #define __BI_QUIRKS_H
26 
27 /* Model-specific quirks requiring compiler workarounds/etc. Quirks
28  * may be errata requiring a workaround, or features. We're trying to be
29  * quirk-positive here; quirky is the best! */
30 
31 /* Whether this GPU lacks support for the preload mechanism. New GPUs can have
32  * varyings and textures preloaded into the fragment shader to amortize the I/O
33  * cost; early Bifrost models lacked this feature. */
34 
35 #define BIFROST_NO_PRELOAD (1 << 0)
36 
37 /* Whether this GPU lacks support for fp32 transcendentals, requiring backend
38  * lowering to low-precision lookup tables and polynomial approximation */
39 
40 #define BIFROST_NO_FP32_TRANSCENDENTALS (1 << 1)
41 
42 /* Whether this GPU lacks support for the full form of the CLPER instruction.
43  * These GPUs use a simple encoding of CLPER that does not support
44  * inactive_result, subgroup_size, or lane_op. Using those features requires
45  * lowering to additional ALU instructions. The encoding forces inactive_result
46  * = zero, subgroup_size = subgroup4, and lane_op = none. */
47 
48 #define BIFROST_LIMITED_CLPER (1 << 2)
49 
50 static inline unsigned
bifrost_get_quirks(unsigned product_id)51 bifrost_get_quirks(unsigned product_id)
52 {
53         switch (product_id >> 8) {
54         case 0x60:
55                 return BIFROST_NO_PRELOAD | BIFROST_NO_FP32_TRANSCENDENTALS |
56                        BIFROST_LIMITED_CLPER;
57         case 0x62:
58                 return BIFROST_NO_PRELOAD | BIFROST_LIMITED_CLPER;
59         case 0x70: /* G31 */
60                 return BIFROST_LIMITED_CLPER;
61         case 0x71:
62         case 0x72:
63         case 0x73:
64         case 0x74:
65                 return 0;
66         case 0x90:
67         case 0x91:
68         case 0x92:
69         case 0x93:
70         case 0x94:
71         case 0x95:
72                 return BIFROST_NO_PRELOAD;
73         default:
74                 unreachable("Unknown Bifrost/Valhall GPU ID");
75         }
76 }
77 
78 /* How many lanes per architectural warp (subgroup)? Used to lower divergent
79  * indirects. */
80 
81 static inline unsigned
bifrost_lanes_per_warp(unsigned product_id)82 bifrost_lanes_per_warp(unsigned product_id)
83 {
84         switch (product_id >> 12) {
85         case 6: return 4;
86         case 7: return 8;
87         case 9: return 16;
88         default: unreachable("Invalid Bifrost/Valhall GPU major");
89         }
90 }
91 
92 #endif
93