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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2015 Imagination Technologies
* Author: Alex Smith <[email protected]>
*/
#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__ */
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