flat.c

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/*
 * Copyright 2007 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/flat.h>

#define FLAT_BFIN_RELOC_TYPE_16_BIT 0
#define FLAT_BFIN_RELOC_TYPE_16H_BIT 1
#define FLAT_BFIN_RELOC_TYPE_32_BIT 2

unsigned long bfin_get_addr_from_rp(unsigned long *ptr,
        unsigned long relval,
        unsigned long flags,
        unsigned long *persistent)
{
    unsigned short *usptr = (unsigned short *)ptr;
    int type = (relval >> 26) & 7;
    unsigned long val;

    switch (type) {
    case FLAT_BFIN_RELOC_TYPE_16_BIT:
    case FLAT_BFIN_RELOC_TYPE_16H_BIT:
        usptr = (unsigned short *)ptr;
        pr_debug("*usptr = %x", get_unaligned(usptr));
        val = get_unaligned(usptr);
        val += *persistent;
        break;

    case FLAT_BFIN_RELOC_TYPE_32_BIT:
        pr_debug("*ptr = %lx", get_unaligned(ptr));
        val = get_unaligned(ptr);
        break;

    default:
        pr_debug("BINFMT_FLAT: Unknown relocation type %x\n", type);
        return 0;
    }

    /*
     * Stack-relative relocs contain the offset into the stack, we
     * have to add the stack's start address here and return 1 from
     * flat_addr_absolute to prevent the normal address calculations
     */
    if (relval & (1 << 29))
        return val + current->mm->context.end_brk;

    if ((flags & FLAT_FLAG_GOTPIC) == 0)
        val = htonl(val);
    return val;
}
EXPORT_SYMBOL(bfin_get_addr_from_rp);

/*
 * Insert the address ADDR into the symbol reference at RP;
 * RELVAL is the raw relocation-table entry from which RP is derived
 */
void bfin_put_addr_at_rp(unsigned long *ptr, unsigned long addr,
        unsigned long relval)
{
    unsigned short *usptr = (unsigned short *)ptr;
    int type = (relval >> 26) & 7;

    switch (type) {
    case FLAT_BFIN_RELOC_TYPE_16_BIT:
        put_unaligned(addr, usptr);
        pr_debug("new value %x at %p", get_unaligned(usptr), usptr);
        break;

    case FLAT_BFIN_RELOC_TYPE_16H_BIT:
        put_unaligned(addr >> 16, usptr);
        pr_debug("new value %x", get_unaligned(usptr));
        break;

    case FLAT_BFIN_RELOC_TYPE_32_BIT:
        put_unaligned(addr, ptr);
        pr_debug("new ptr =%lx", get_unaligned(ptr));
        break;
    }
}
EXPORT_SYMBOL(bfin_put_addr_at_rp);