/* SPDX-License-Identifier: GPL-2.0 */
/*
 * uClinux flat-format executables
 *
 * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
 */

#ifndef _ASM_MICROBLAZE_FLAT_H
#define _ASM_MICROBLAZE_FLAT_H

#include <linux/unaligned.h>

/*
 * Microblaze works a little differently from other arches, because
 * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
 * over two instructions, an 'imm' instruction which provides the top
 * 16 bits, then the instruction "proper" which provides the low 16
 * bits.
 */

/*
 * Crack open a symbol reference and extract the address to be
 * relocated. rp is a potentially unaligned pointer to the
 * reference
 */

static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
                                        u32 *addr)
{
        u32 *p = (__force u32 *)rp;

        /* Is it a split 64/32 reference? */
        if (relval & 0x80000000) {
                /* Grab the two halves of the reference */
                u32 val_hi, val_lo;

                val_hi = get_unaligned(p);
                val_lo = get_unaligned(p+1);

                /* Crack the address out */
                *addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
        } else {
                /* Get the address straight out */
                *addr = get_unaligned(p);
        }

        return 0;
}

/*
 * Insert an address into the symbol reference at rp. rp is potentially
 * unaligned.
 */

static inline int
flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 relval)
{
        u32 *p = (__force u32 *)rp;
        /* Is this a split 64/32 reloc? */
        if (relval & 0x80000000) {
                /* Get the two "halves" */
                unsigned long val_hi = get_unaligned(p);
                unsigned long val_lo = get_unaligned(p + 1);

                /* insert the address */
                val_hi = (val_hi & 0xffff0000) | addr >> 16;
                val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);

                /* store the two halves back into memory */
                put_unaligned(val_hi, p);
                put_unaligned(val_lo, p+1);
        } else {
                /* Put it straight in, no messing around */
                put_unaligned(addr, p);
        }
        return 0;
}

#define flat_get_relocate_addr(rel)     (rel & 0x7fffffff)

#endif /* _ASM_MICROBLAZE_FLAT_H */