1 | /* powerpc HWCAP/HWCAP2 and AT_PLATFORM data pre-processing. |
2 | Copyright (C) 2015-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <unistd.h> |
20 | #include <shlib-compat.h> |
21 | #include <dl-procinfo.h> |
22 | |
23 | uint64_t __tcb_hwcap __attribute__ ((visibility ("hidden" ))); |
24 | uint32_t __tcb_platform __attribute__ ((visibility ("hidden" ))); |
25 | |
26 | /* This function parses the HWCAP/HWCAP2 fields, adding the previous supported |
27 | ISA bits, as well as converting the AT_PLATFORM string to a number. This |
28 | data is stored in two global variables that can be used later by the |
29 | powerpc-specific code to store it into the TCB. */ |
30 | void |
31 | __tcb_parse_hwcap_and_convert_at_platform (void) |
32 | { |
33 | |
34 | uint64_t h1, h2; |
35 | |
36 | /* Read AT_PLATFORM string from auxv and convert it to a number. */ |
37 | __tcb_platform = _dl_string_platform (GLRO (dl_platform)); |
38 | |
39 | /* Read HWCAP and HWCAP2 from auxv. */ |
40 | h1 = GLRO (dl_hwcap); |
41 | h2 = GLRO (dl_hwcap2); |
42 | |
43 | /* hwcap contains only the latest supported ISA, the code checks which is |
44 | and fills the previous supported ones. */ |
45 | |
46 | if (h2 & PPC_FEATURE2_ARCH_2_07) |
47 | h1 |= PPC_FEATURE_ARCH_2_06 |
48 | | PPC_FEATURE_ARCH_2_05 |
49 | | PPC_FEATURE_POWER5_PLUS |
50 | | PPC_FEATURE_POWER5 |
51 | | PPC_FEATURE_POWER4; |
52 | else if (h1 & PPC_FEATURE_ARCH_2_06) |
53 | h1 |= PPC_FEATURE_ARCH_2_05 |
54 | | PPC_FEATURE_POWER5_PLUS |
55 | | PPC_FEATURE_POWER5 |
56 | | PPC_FEATURE_POWER4; |
57 | else if (h1 & PPC_FEATURE_ARCH_2_05) |
58 | h1 |= PPC_FEATURE_POWER5_PLUS |
59 | | PPC_FEATURE_POWER5 |
60 | | PPC_FEATURE_POWER4; |
61 | else if (h1 & PPC_FEATURE_POWER5_PLUS) |
62 | h1 |= PPC_FEATURE_POWER5 |
63 | | PPC_FEATURE_POWER4; |
64 | else if (h1 & PPC_FEATURE_POWER5) |
65 | h1 |= PPC_FEATURE_POWER4; |
66 | |
67 | /* Consolidate both HWCAP and HWCAP2 into a single doubleword so that |
68 | we can read both in a single load later. */ |
69 | __tcb_hwcap = h2; |
70 | __tcb_hwcap = (h1 << 32) | __tcb_hwcap; |
71 | |
72 | } |
73 | #if IS_IN (rtld) |
74 | versioned_symbol (ld, __tcb_parse_hwcap_and_convert_at_platform, \ |
75 | __parse_hwcap_and_convert_at_platform, GLIBC_2_23); |
76 | #endif |
77 | |
78 | /* Export __parse_hwcap_and_convert_at_platform in libc.a. This is used by |
79 | GCC to make sure that the HWCAP/Platform bits are stored in the TCB when |
80 | using __builtin_cpu_is()/__builtin_cpu_supports() in the static case. */ |
81 | #ifndef SHARED |
82 | weak_alias (__tcb_parse_hwcap_and_convert_at_platform, \ |
83 | __parse_hwcap_and_convert_at_platform); |
84 | #endif |
85 | |