static u32 get_alt_insn(struct alt_instr *alt, u32 *insnptr, u32 *altinsnptr)
{
u32 insn;
insn = le32_to_cpu(*altinsnptr);
if (aarch64_insn_is_branch_imm(insn)) {
s32 offset = aarch64_get_branch_offset(insn);
unsigned long target;
target = (unsigned long)altinsnptr + offset;
/*
* If we're branching inside the alternate sequence,
* do not rewrite the instruction, as it is already
* correct. Otherwise, generate the new instruction.
*/
if (branch_insn_requires_update(alt, target)) {
offset = target - (unsigned long)insnptr;
insn = aarch64_set_branch_offset(insn, offset);
}
}
return insn;
}
static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnptr)
{
u32 insn;
insn = le32_to_cpu(*altinsnptr);
if (aarch64_insn_is_branch_imm(insn)) {
s32 offset = aarch64_get_branch_offset(insn);
unsigned long target;
target = (unsigned long)altinsnptr + offset;
/*
* If we're branching inside the alternate sequence,
* do not rewrite the instruction, as it is already
* correct. Otherwise, generate the new instruction.
*/
if (branch_insn_requires_update(alt, target)) {
offset = target - (unsigned long)insnptr;
insn = aarch64_set_branch_offset(insn, offset);
}
} else if (aarch64_insn_is_adrp(insn)) {
s32 orig_offset, new_offset;
unsigned long target;
/*
* If we're replacing an adrp instruction, which uses PC-relative
* immediate addressing, adjust the offset to reflect the new
* PC. adrp operates on 4K aligned addresses.
*/
orig_offset = aarch64_insn_adrp_get_offset(insn);
target = align_down(altinsnptr, SZ_4K) + orig_offset;
new_offset = target - align_down(insnptr, SZ_4K);
insn = aarch64_insn_adrp_set_offset(insn, new_offset);
} else if (aarch64_insn_uses_literal(insn)) {
/*
* Disallow patching unhandled instructions using PC relative
* literal addresses
*/
BUG();
}
return insn;
}
