target/arm: Separate decode from handling of coproc insns

As a prelude to making coproc insns use decodetree, split out the
part of disas_coproc_insn() which does instruction decoding from the
part which does the actual work, and make do_coproc_insn() handle the
UNDEF-on-bad-permissions and similar cases itself rather than
returning 1 to eventually percolate up to a callsite that calls
unallocated_encoding() for it.

Backports 19c23a9baafc91dd3881a7a4e9bf454e42d24e4e
This commit is contained in:
Peter Maydell 2021-02-26 10:53:49 -05:00 committed by Lioncash
parent 2944a75b98
commit ef0e23f1f9

View file

@ -4639,41 +4639,20 @@ void gen_gvec_uaba(TCGContext *s, unsigned vece, uint32_t rd_ofs, uint32_t rn_of
tcg_gen_gvec_3(s, rd_ofs, rn_ofs, rm_ofs, opr_sz, max_sz, &ops[vece]);
}
static int disas_coproc_insn(DisasContext *s, uint32_t insn)
static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
int opc1, int crn, int crm, int opc2,
bool isread, int rt, int rt2)
{
int cpnum, is64, crn, crm, opc1, opc2, isread, rt, rt2;
const ARMCPRegInfo *ri;
TCGContext *tcg_ctx = s->uc->tcg_ctx;
cpnum = (insn >> 8) & 0xf;
is64 = (insn & (1 << 25)) == 0;
if (!is64 && ((insn & (1 << 4)) == 0)) {
/* cdp */
return 1;
}
crm = insn & 0xf;
if (is64) {
crn = 0;
opc1 = (insn >> 4) & 0xf;
opc2 = 0;
rt2 = (insn >> 16) & 0xf;
} else {
crn = (insn >> 16) & 0xf;
opc1 = (insn >> 21) & 7;
opc2 = (insn >> 5) & 7;
rt2 = 0;
}
isread = (insn >> 20) & 1;
rt = (insn >> 12) & 0xf;
ri = get_arm_cp_reginfo(s->cp_regs,
ENCODE_CP_REG(cpnum, is64, s->ns, crn, crm, opc1, opc2));
if (ri) {
/* Check access permissions */
if (!cp_access_ok(s->current_el, ri, isread)) {
return 1;
unallocated_encoding(s);
return;
}
if (s->hstr_active || ri->accessfn ||
@ -4747,25 +4726,19 @@ static int disas_coproc_insn(DisasContext *s, uint32_t insn)
/* Handle special cases first */
switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) {
case ARM_CP_NOP:
return 0;
return;
case ARM_CP_WFI:
if (isread) {
return 1;
unallocated_encoding(s);
return;
}
gen_set_pc_im(s, s->base.pc_next);
s->base.is_jmp = DISAS_WFI;
return 0;
return;
default:
break;
}
// Unicorn: if'd out
#if 0
if ((tb_cflags(s->base.tb) & CF_USE_ICOUNT) && (ri->type & ARM_CP_IO)) {
gen_io_start();
}
#endif
if (isread) {
/* Read */
if (is64) {
@ -4817,7 +4790,7 @@ static int disas_coproc_insn(DisasContext *s, uint32_t insn)
/* Write */
if (ri->type & ARM_CP_CONST) {
/* If not forbidden by access permissions, treat as WI */
return 0;
return;
}
if (is64) {
@ -4865,7 +4838,7 @@ static int disas_coproc_insn(DisasContext *s, uint32_t insn)
gen_lookup_tb(s);
}
return 0;
return;
}
/* Unknown register; this might be a guest error or a QEMU
@ -4885,7 +4858,39 @@ static int disas_coproc_insn(DisasContext *s, uint32_t insn)
s->ns ? "non-secure" : "secure");
}
return 1;
unallocated_encoding(s);
return;
}
static int disas_coproc_insn(DisasContext *s, uint32_t insn)
{
int cpnum, is64, crn, crm, opc1, opc2, isread, rt, rt2;
cpnum = (insn >> 8) & 0xf;
is64 = (insn & (1 << 25)) == 0;
if (!is64 && ((insn & (1 << 4)) == 0)) {
/* cdp */
return 1;
}
crm = insn & 0xf;
if (is64) {
crn = 0;
opc1 = (insn >> 4) & 0xf;
opc2 = 0;
rt2 = (insn >> 16) & 0xf;
} else {
crn = (insn >> 16) & 0xf;
opc1 = (insn >> 21) & 7;
opc2 = (insn >> 5) & 7;
rt2 = 0;
}
isread = (insn >> 20) & 1;
rt = (insn >> 12) & 0xf;
do_coproc_insn(s, cpnum, is64, opc1, crn, crm, opc2, isread, rt, rt2);
return 0;
}
/* Decode XScale DSP or iWMMXt insn (in the copro space, cp=0 or 1) */