Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0-only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * vvar.h: Shared vDSO/kernel variable declarations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * Copyright (c) 2011 Andy Lutomirski
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * A handful of variables are accessible (read-only) from userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * code in the vsyscall page and the vdso.  They are declared here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * Some other file must define them with DEFINE_VVAR.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * In normal kernel code, they are used like any other variable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * In user code, they are accessed through the VVAR macro.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * These variables live in a page of kernel data that has an extra RO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * mapping for userspace.  Each variable needs a unique offset within
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * that page; specify that offset with the DECLARE_VVAR macro.  (If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * you mess up, the linker will catch it.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #ifndef _ASM_X86_VVAR_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #define _ASM_X86_VVAR_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #ifdef EMIT_VVAR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * EMIT_VVAR() is used by the kernel linker script to put vvars in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * right place. Also, it's used by kernel code to import offsets values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #define DECLARE_VVAR(offset, type, name) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	EMIT_VVAR(name, offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) extern char __vvar_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #define DECLARE_VVAR(offset, type, name)				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	extern type vvar_ ## name[CS_BASES]				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	__attribute__((visibility("hidden")));				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	extern type timens_ ## name[CS_BASES]				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	__attribute__((visibility("hidden")));				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #define VVAR(name) (vvar_ ## name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #define TIMENS(name) (timens_ ## name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #define DEFINE_VVAR(type, name)						\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	type name[CS_BASES]						\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	__attribute__((section(".vvar_" #name), aligned(16))) __visible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /* DECLARE_VVAR(offset, type, name) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) DECLARE_VVAR(128, struct vdso_data, _vdso_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #undef DECLARE_VVAR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) #endif