xref: /linux/arch/loongarch/include/asm/vdso/getrandom.h (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2024 Xi Ruoyao <xry111@xry111.site>. All Rights Reserved.
4  */
5 #ifndef __ASM_VDSO_GETRANDOM_H
6 #define __ASM_VDSO_GETRANDOM_H
7 
8 #ifndef __ASSEMBLY__
9 
10 #include <asm/unistd.h>
11 #include <asm/vdso/vdso.h>
12 
13 static __always_inline ssize_t getrandom_syscall(void *_buffer, size_t _len, unsigned int _flags)
14 {
15 	register long ret asm("a0");
16 	register long nr asm("a7") = __NR_getrandom;
17 	register void *buffer asm("a0") = _buffer;
18 	register size_t len asm("a1") = _len;
19 	register unsigned int flags asm("a2") = _flags;
20 
21 	asm volatile(
22 	"      syscall 0\n"
23 	: "+r" (ret)
24 	: "r" (nr), "r" (buffer), "r" (len), "r" (flags)
25 	: "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8",
26 	  "memory");
27 
28 	return ret;
29 }
30 
31 static __always_inline const struct vdso_rng_data *__arch_get_vdso_rng_data(void)
32 {
33 	return (const struct vdso_rng_data *)(get_vdso_data() + VVAR_LOONGARCH_PAGES_START *
34 	       PAGE_SIZE + offsetof(struct loongarch_vdso_data, rng_data));
35 }
36 
37 #endif /* !__ASSEMBLY__ */
38 
39 #endif /* __ASM_VDSO_GETRANDOM_H */
40