/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2015 Imagination Technologies
 * Author: Alex Smith <alex.smith@imgtec.com>
 */

#include <asm/sgidefs.h>
#include <vdso/page.h>

#define __VDSO_PAGES 4

#ifndef __ASSEMBLER__

#include <asm/asm.h>
#include <asm/vdso.h>

static inline const struct vdso_time_data *get_vdso_time_data(void)
{
        const struct vdso_time_data *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, vdso_u_time_data            \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 perform
         * 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   vdso_u_time_data - .            \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;
}

#ifdef CONFIG_CLKSRC_MIPS_GIC

static inline void __iomem *get_gic(const struct vdso_time_data *data)
{
        return (void __iomem *)((unsigned long)data & PAGE_MASK) - PAGE_SIZE;
}

#endif /* CONFIG_CLKSRC_MIPS_GIC */

#endif /* __ASSEMBLER__ */