| 1 | /* powerpc HWCAP/HWCAP2 and AT_PLATFORM data pre-processing. |
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| 2 | Copyright (C) 2015-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <unistd.h> |
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| 20 | #include <shlib-compat.h> |
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| 21 | #include <dl-procinfo.h> |
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| 22 | #include <cpu-features.c> |
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| 23 | |
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| 24 | tcbhead_t __tcb __attribute__ ((visibility ("hidden" ))); |
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| 25 | |
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| 26 | /* This function parses the HWCAP/HWCAP2 fields, adding the previous supported |
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| 27 | ISA bits, as well as converting the AT_PLATFORM string to a number. This |
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| 28 | data is stored in two global variables that can be used later by the |
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| 29 | powerpc-specific code to store it into the TCB. */ |
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| 30 | void |
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| 31 | __tcb_parse_hwcap_and_convert_at_platform (void) |
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| 32 | { |
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| 33 | |
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| 34 | uint64_t h1, h2, h3, h4; |
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| 35 | |
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| 36 | /* Read AT_PLATFORM string from auxv and convert it to a number. */ |
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| 37 | __tcb.at_platform = _dl_string_platform (GLRO (dl_platform)); |
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| 38 | |
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| 39 | /* Read HWCAP and HWCAP2 from auxv. */ |
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| 40 | h1 = GLRO (dl_hwcap); |
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| 41 | h2 = GLRO (dl_hwcap2); |
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| 42 | h3 = GLRO (dl_hwcap3); |
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| 43 | h4 = GLRO (dl_hwcap4); |
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| 44 | |
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| 45 | /* hwcap contains only the latest supported ISA, the code checks which is |
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| 46 | and fills the previous supported ones. */ |
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| 47 | |
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| 48 | if (h2 & PPC_FEATURE2_ARCH_2_07) |
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| 49 | h1 |= PPC_FEATURE_ARCH_2_06 |
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| 50 | | PPC_FEATURE_ARCH_2_05 |
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| 51 | | PPC_FEATURE_POWER5_PLUS |
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| 52 | | PPC_FEATURE_POWER5 |
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| 53 | | PPC_FEATURE_POWER4; |
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| 54 | else if (h1 & PPC_FEATURE_ARCH_2_06) |
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| 55 | h1 |= PPC_FEATURE_ARCH_2_05 |
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| 56 | | PPC_FEATURE_POWER5_PLUS |
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| 57 | | PPC_FEATURE_POWER5 |
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| 58 | | PPC_FEATURE_POWER4; |
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| 59 | else if (h1 & PPC_FEATURE_ARCH_2_05) |
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| 60 | h1 |= PPC_FEATURE_POWER5_PLUS |
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| 61 | | PPC_FEATURE_POWER5 |
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| 62 | | PPC_FEATURE_POWER4; |
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| 63 | else if (h1 & PPC_FEATURE_POWER5_PLUS) |
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| 64 | h1 |= PPC_FEATURE_POWER5 |
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| 65 | | PPC_FEATURE_POWER4; |
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| 66 | else if (h1 & PPC_FEATURE_POWER5) |
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| 67 | h1 |= PPC_FEATURE_POWER4; |
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| 68 | |
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| 69 | uint64_t array_hwcaps[] = { h1, h2, h3, h4 }; |
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| 70 | init_cpu_features (cpu_features: &GLRO(dl_powerpc_cpu_features), array_hwcaps); |
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| 71 | |
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| 72 | /* Consolidate both HWCAP and HWCAP2 into a single doubleword so that |
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| 73 | we can read both in a single load later. */ |
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| 74 | __tcb.hwcap = (h1 << 32) | (h2 & 0xffffffff); |
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| 75 | |
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| 76 | /* Consolidate both HWCAP3 and HWCAP4 into a single doubleword so that |
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| 77 | we can read both in a single load later. */ |
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| 78 | __tcb.hwcap_extn = (h3 << 32) | (h4 & 0xffffffff); |
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| 79 | |
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| 80 | } |
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| 81 | #if IS_IN (rtld) |
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| 82 | versioned_symbol (ld, __tcb_parse_hwcap_and_convert_at_platform, \ |
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| 83 | __parse_hwcap_and_convert_at_platform, GLIBC_2_23); |
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| 84 | versioned_symbol (ld, __tcb_parse_hwcap_and_convert_at_platform, \ |
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| 85 | __parse_hwcap_3_4_and_convert_at_platform, GLIBC_2_39); |
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| 86 | #endif |
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| 87 | |
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| 88 | /* Export __parse_hwcap_and_convert_at_platform in libc.a. This is used by |
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| 89 | GCC to make sure that the HWCAP/Platform bits are stored in the TCB when |
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| 90 | using __builtin_cpu_is()/__builtin_cpu_supports() in the static case. */ |
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| 91 | #ifndef SHARED |
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| 92 | weak_alias (__tcb_parse_hwcap_and_convert_at_platform, \ |
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| 93 | __parse_hwcap_and_convert_at_platform); |
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| 94 | weak_alias (__tcb_parse_hwcap_and_convert_at_platform, \ |
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| 95 | __parse_hwcap_3_4_and_convert_at_platform); |
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| 96 | #endif |
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| 97 | |
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