/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * XIP fixup macros, only useful in assembly.
 */
#ifndef _ASM_RISCV_XIP_FIXUP_H
#define _ASM_RISCV_XIP_FIXUP_H

#include <linux/pgtable.h>

#ifdef CONFIG_XIP_KERNEL
.macro XIP_FIXUP_OFFSET reg
        /* Fix-up address in Flash into address in RAM early during boot before
         * MMU is up. Because generated code "thinks" data is in Flash, but it
         * is actually in RAM (actually data is also in Flash, but Flash is
         * read-only, thus we need to use the data residing in RAM).
         *
         * The start of data in Flash is _sdata and the start of data in RAM is
         * CONFIG_PHYS_RAM_BASE. So this fix-up essentially does this:
         * reg += CONFIG_PHYS_RAM_BASE - _start
         */
        li t0, CONFIG_PHYS_RAM_BASE
        add \reg, \reg, t0
        la t0, _sdata
        sub \reg, \reg, t0
.endm
.macro XIP_FIXUP_FLASH_OFFSET reg
        /* In linker script, at the transition from read-only section to
         * writable section, the VMA is increased while LMA remains the same.
         * (See in linker script how _sdata, __data_loc and LOAD_OFFSET is
         * changed)
         *
         * Consequently, early during boot before MMU is up, the generated code
         * reads the "writable" section at wrong addresses, because VMA is used
         * by compiler to generate code, but the data is located in Flash using
         * LMA.
         */
        la t0, _sdata
        sub \reg, \reg, t0
        la t0, __data_loc
        add \reg, \reg, t0
.endm
#else
.macro XIP_FIXUP_OFFSET reg
.endm
.macro XIP_FIXUP_FLASH_OFFSET reg
.endm
#endif /* CONFIG_XIP_KERNEL */

#endif