1 /* RISC-V instruction cache flushing VDSO calls
2 Copyright (C) 2017-2020 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <stdlib.h>
19 #include <atomic.h>
20 #include <sys/syscall.h>
21
22 #ifndef __NR_riscv_flush_icache
23 #define __NR_riscv_flush_icache 259
24 #endif
25
26 typedef int (*func_type) (void *, void *, unsigned long int);
27
28 static int
__riscv_flush_icache_syscall(void * start,void * end,unsigned long int flags)29 __riscv_flush_icache_syscall (void *start, void *end, unsigned long int flags)
30 {
31 return INLINE_SYSCALL (riscv_flush_icache, 3, start, end, flags);
32 }
33
34 static func_type
__lookup_riscv_flush_icache(void)35 __lookup_riscv_flush_icache (void)
36 {
37 /* always call the system call directly.*/
38 return &__riscv_flush_icache_syscall;
39 }
40
41 int
__riscv_flush_icache(void * start,void * end,unsigned long int flags)42 __riscv_flush_icache (void *start, void *end, unsigned long int flags)
43 {
44 static volatile func_type cached_func;
45
46 func_type func = atomic_load_relaxed (&cached_func);
47
48 if (!func)
49 {
50 func = __lookup_riscv_flush_icache ();
51 atomic_store_relaxed (&cached_func, func);
52 }
53
54 return func (start, end, flags);
55 }
56