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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_EXTABLE_H
#define _ASM_EXTABLE_H
/*
* About the exception table:
*
* - insn is a 32-bit pc-relative offset from the faulting insn.
* - nextinsn is a 16-bit offset off of the faulting instruction
* (not off of the *next* instruction as branches are).
* - errreg is the register in which to place -EFAULT.
* - valreg is the final target register for the load sequence
* and will be zeroed.
*
* Either errreg or valreg may be $31, in which case nothing happens.
*
* The exception fixup information "just so happens" to be arranged
* as in a MEM format instruction. This lets us emit our three
* values like so:
*
* lda valreg, nextinsn(errreg)
*
*/
struct exception_table_entry
{
signed int insn;
union exception_fixup {
unsigned unit;
struct {
signed int nextinsn : 16;
unsigned int errreg : 5;
unsigned int valreg : 5;
} bits;
} fixup;
};
/* Returns the new pc */
#define fixup_exception(map_reg, _fixup, pc) \
({ \
if ((_fixup)->fixup.bits.valreg != 31) \
map_reg((_fixup)->fixup.bits.valreg) = 0; \
if ((_fixup)->fixup.bits.errreg != 31) \
map_reg((_fixup)->fixup.bits.errreg) = -EFAULT; \
(pc) + (_fixup)->fixup.bits.nextinsn; \
})
#define ARCH_HAS_RELATIVE_EXTABLE
#define swap_ex_entry_fixup(a, b, tmp, delta) \
do { \
(a)->fixup.unit = (b)->fixup.unit; \
(b)->fixup.unit = (tmp).fixup.unit; \
} while (0)
#endif
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