76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* Copyright (C) 2015 Imagination Technologies
|
|
* Author: Alex Smith <alex.smith@imgtec.com>
|
|
*/
|
|
|
|
#include <asm/sgidefs.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/page.h>
|
|
#include <asm/vdso.h>
|
|
|
|
static inline unsigned long get_vdso_base(void)
|
|
{
|
|
unsigned long addr;
|
|
|
|
/*
|
|
* We can't use cpu_has_mips_r6 since it needs the cpu_data[]
|
|
* kernel symbol.
|
|
*/
|
|
#ifdef CONFIG_CPU_MIPSR6
|
|
/*
|
|
* lapc <symbol> is an alias to addiupc reg, <symbol> - .
|
|
*
|
|
* We can't use addiupc because there is no label-label
|
|
* support for the addiupc reloc
|
|
*/
|
|
__asm__("lapc %0, _start \n"
|
|
: "=r" (addr) : :);
|
|
#else
|
|
/*
|
|
* Get the base load address of the VDSO. We have to avoid generating
|
|
* relocations and references to the GOT because ld.so does not peform
|
|
* relocations on the VDSO. We use the current offset from the VDSO base
|
|
* and perform a PC-relative branch which gives the absolute address in
|
|
* ra, and take the difference. The assembler chokes on
|
|
* "li %0, _start - .", so embed the offset as a word and branch over
|
|
* it.
|
|
*
|
|
*/
|
|
|
|
__asm__(
|
|
" .set push \n"
|
|
" .set noreorder \n"
|
|
" bal 1f \n"
|
|
" nop \n"
|
|
" .word _start - . \n"
|
|
"1: lw %0, 0($31) \n"
|
|
" " STR(PTR_ADDU) " %0, $31, %0 \n"
|
|
" .set pop \n"
|
|
: "=r" (addr)
|
|
:
|
|
: "$31");
|
|
#endif /* CONFIG_CPU_MIPSR6 */
|
|
|
|
return addr;
|
|
}
|
|
|
|
static inline const struct vdso_data *get_vdso_data(void)
|
|
{
|
|
return (const struct vdso_data *)(get_vdso_base() - PAGE_SIZE);
|
|
}
|
|
|
|
#ifdef CONFIG_CLKSRC_MIPS_GIC
|
|
|
|
static inline void __iomem *get_gic(const struct vdso_data *data)
|
|
{
|
|
return (void __iomem *)((unsigned long)data & PAGE_MASK) - PAGE_SIZE;
|
|
}
|
|
|
|
#endif /* CONFIG_CLKSRC_MIPS_GIC */
|
|
|
|
#endif /* __ASSEMBLY__ */
|