/*
|
* Copyright (C) 2015 Imagination Technologies
|
* Author: Alex Smith <alex.smith@imgtec.com>
|
*
|
* This program is free software; you can redistribute it and/or modify it
|
* under the terms of the GNU General Public License as published by the
|
* Free Software Foundation; either version 2 of the License, or (at your
|
* option) any later version.
|
*/
|
|
#include <asm/sgidefs.h>
|
|
#if _MIPS_SIM != _MIPS_SIM_ABI64 && defined(CONFIG_64BIT)
|
|
/* Building 32-bit VDSO for the 64-bit kernel. Fake a 32-bit Kconfig. */
|
#define BUILD_VDSO32_64
|
#undef CONFIG_64BIT
|
#define CONFIG_32BIT 1
|
#ifndef __ASSEMBLY__
|
#include <asm-generic/atomic64.h>
|
#endif
|
#endif
|
|
#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__ */
|
