| 1 | /* RISC-V instruction cache flushing VDSO calls |
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| 2 | Copyright (C) 2017-2022 Free Software Foundation, Inc. |
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| 3 | |
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| 4 | This file is part of the GNU C Library. |
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| 5 | |
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| 6 | The GNU C Library is free software; you can redistribute it and/or |
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| 7 | modify it under the terms of the GNU Lesser General Public License as |
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| 8 | published by the Free Software Foundation; either version 2.1 of the |
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| 9 | License, or (at your option) any later version. |
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| 10 | |
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| 11 | The GNU C Library is distributed in the hope that it will be useful, |
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | Lesser General Public License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU Lesser General Public |
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| 17 | License along with the GNU C Library; if not, see |
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| 18 | <https://www.gnu.org/licenses/>. */ |
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| 19 | |
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| 20 | #include <dl-vdso.h> |
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| 21 | #include <stdlib.h> |
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| 22 | #include <atomic.h> |
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| 23 | #include <sys/cachectl.h> |
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| 24 | #if __has_include (<asm/syscalls.h>) |
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| 25 | # include <asm/syscalls.h> |
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| 26 | #else |
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| 27 | # include <asm/unistd.h> |
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| 28 | #endif |
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| 29 | #include <sys/syscall.h> |
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| 30 | |
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| 31 | typedef int (*func_type) (void *, void *, unsigned long int); |
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| 32 | |
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| 33 | static int |
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| 34 | __riscv_flush_icache_syscall (void *start, void *end, unsigned long int flags) |
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| 35 | { |
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| 36 | return INLINE_SYSCALL (riscv_flush_icache, 3, start, end, flags); |
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| 37 | } |
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| 38 | |
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| 39 | static func_type |
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| 40 | __lookup_riscv_flush_icache (void) |
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| 41 | { |
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| 42 | func_type func = dl_vdso_vsym (name: "__vdso_flush_icache" ); |
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| 43 | |
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| 44 | /* If there is no vDSO entry then call the system call directly. All Linux |
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| 45 | versions provide the vDSO entry, but QEMU's user-mode emulation doesn't |
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| 46 | provide a vDSO. */ |
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| 47 | if (!func) |
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| 48 | func = &__riscv_flush_icache_syscall; |
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| 49 | |
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| 50 | return func; |
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| 51 | } |
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| 52 | |
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| 53 | #ifdef SHARED |
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| 54 | |
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| 55 | # define INIT_ARCH() |
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| 56 | libc_ifunc (__riscv_flush_icache, __lookup_riscv_flush_icache ()) |
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| 57 | |
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| 58 | #else |
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| 59 | |
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| 60 | int |
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| 61 | __riscv_flush_icache (void *start, void *end, unsigned long int flags) |
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| 62 | { |
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| 63 | static volatile func_type cached_func; |
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| 64 | |
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| 65 | func_type func = atomic_load_relaxed (&cached_func); |
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| 66 | |
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| 67 | if (!func) |
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| 68 | { |
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| 69 | func = __lookup_riscv_flush_icache (); |
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| 70 | atomic_store_relaxed (&cached_func, func); |
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| 71 | } |
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| 72 | |
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| 73 | return func (start, end, flags); |
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| 74 | } |
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| 75 | |
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| 76 | #endif |
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| 77 | |
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