@@ -215,3 +215,18 @@ MSR_i_SVCR 1101 0101 0000 0 011 0100 0 mask:2 imm:1 011 11111
SYS 1101 0101 00 l:1 01 op1:3 crn:4 crm:4 op2:3 rt:5 op0=1
SYS 1101 0101 00 l:1 10 op1:3 crn:4 crm:4 op2:3 rt:5 op0=2
SYS 1101 0101 00 l:1 11 op1:3 crn:4 crm:4 op2:3 rt:5 op0=3
+
+# Exception generation
+
+@i16 .... .... ... imm:16 ... .. &i
+SVC 1101 0100 000 ................ 000 01 @i16
+HVC 1101 0100 000 ................ 000 10 @i16
+SMC 1101 0100 000 ................ 000 11 @i16
+BRK 1101 0100 001 ................ 000 00 @i16
+HLT 1101 0100 010 ................ 000 00 @i16
+# These insns always UNDEF unless in halting debug state, which
+# we don't implement. So we don't need to decode them. The patterns
+# are listed here as documentation.
+# DCPS1 1101 0100 101 ................ 000 01 @i16
+# DCPS2 1101 0100 101 ................ 000 10 @i16
+# DCPS3 1101 0100 101 ................ 000 11 @i16
@@ -2260,119 +2260,77 @@ static bool trans_SYS(DisasContext *s, arg_SYS *a)
return true;
}
-/* Exception generation
- *
- * 31 24 23 21 20 5 4 2 1 0
- * +-----------------+-----+------------------------+-----+----+
- * | 1 1 0 1 0 1 0 0 | opc | imm16 | op2 | LL |
- * +-----------------------+------------------------+----------+
- */
-static void disas_exc(DisasContext *s, uint32_t insn)
+static bool trans_SVC(DisasContext *s, arg_i *a)
{
- int opc = extract32(insn, 21, 3);
- int op2_ll = extract32(insn, 0, 5);
- int imm16 = extract32(insn, 5, 16);
- uint32_t syndrome;
-
- switch (opc) {
- case 0:
- /* For SVC, HVC and SMC we advance the single-step state
- * machine before taking the exception. This is architecturally
- * mandated, to ensure that single-stepping a system call
- * instruction works properly.
- */
- switch (op2_ll) {
- case 1: /* SVC */
- syndrome = syn_aa64_svc(imm16);
- if (s->fgt_svc) {
- gen_exception_insn_el(s, 0, EXCP_UDEF, syndrome, 2);
- break;
- }
- gen_ss_advance(s);
- gen_exception_insn(s, 4, EXCP_SWI, syndrome);
- break;
- case 2: /* HVC */
- if (s->current_el == 0) {
- unallocated_encoding(s);
- break;
- }
- /* The pre HVC helper handles cases when HVC gets trapped
- * as an undefined insn by runtime configuration.
- */
- gen_a64_update_pc(s, 0);
- gen_helper_pre_hvc(cpu_env);
- gen_ss_advance(s);
- gen_exception_insn_el(s, 4, EXCP_HVC, syn_aa64_hvc(imm16), 2);
- break;
- case 3: /* SMC */
- if (s->current_el == 0) {
- unallocated_encoding(s);
- break;
- }
- gen_a64_update_pc(s, 0);
- gen_helper_pre_smc(cpu_env, tcg_constant_i32(syn_aa64_smc(imm16)));
- gen_ss_advance(s);
- gen_exception_insn_el(s, 4, EXCP_SMC, syn_aa64_smc(imm16), 3);
- break;
- default:
- unallocated_encoding(s);
- break;
- }
- break;
- case 1:
- if (op2_ll != 0) {
- unallocated_encoding(s);
- break;
- }
- /* BRK */
- gen_exception_bkpt_insn(s, syn_aa64_bkpt(imm16));
- break;
- case 2:
- if (op2_ll != 0) {
- unallocated_encoding(s);
- break;
- }
- /* HLT. This has two purposes.
- * Architecturally, it is an external halting debug instruction.
- * Since QEMU doesn't implement external debug, we treat this as
- * it is required for halting debug disabled: it will UNDEF.
- * Secondly, "HLT 0xf000" is the A64 semihosting syscall instruction.
- */
- if (semihosting_enabled(s->current_el == 0) && imm16 == 0xf000) {
- gen_exception_internal_insn(s, EXCP_SEMIHOST);
- } else {
- unallocated_encoding(s);
- }
- break;
- case 5:
- if (op2_ll < 1 || op2_ll > 3) {
- unallocated_encoding(s);
- break;
- }
- /* DCPS1, DCPS2, DCPS3 */
- unallocated_encoding(s);
- break;
- default:
- unallocated_encoding(s);
- break;
+ /*
+ * For SVC, HVC and SMC we advance the single-step state
+ * machine before taking the exception. This is architecturally
+ * mandated, to ensure that single-stepping a system call
+ * instruction works properly.
+ */
+ uint32_t syndrome = syn_aa64_svc(a->imm);
+ if (s->fgt_svc) {
+ gen_exception_insn_el(s, 0, EXCP_UDEF, syndrome, 2);
+ return true;
}
+ gen_ss_advance(s);
+ gen_exception_insn(s, 4, EXCP_SWI, syndrome);
+ return true;
}
-/* Branches, exception generating and system instructions */
-static void disas_b_exc_sys(DisasContext *s, uint32_t insn)
+static bool trans_HVC(DisasContext *s, arg_i *a)
{
- switch (extract32(insn, 25, 7)) {
- case 0x6a: /* Exception generation / System */
- if (insn & (1 << 24)) {
- unallocated_encoding(s);
- } else {
- disas_exc(s, insn);
- }
- break;
- default:
+ if (s->current_el == 0) {
unallocated_encoding(s);
- break;
+ return true;
}
+ /*
+ * The pre HVC helper handles cases when HVC gets trapped
+ * as an undefined insn by runtime configuration.
+ */
+ gen_a64_update_pc(s, 0);
+ gen_helper_pre_hvc(cpu_env);
+ /* Architecture requires ss advance before we do the actual work */
+ gen_ss_advance(s);
+ gen_exception_insn_el(s, 4, EXCP_HVC, syn_aa64_hvc(a->imm), 2);
+ return true;
+}
+
+static bool trans_SMC(DisasContext *s, arg_i *a)
+{
+ if (s->current_el == 0) {
+ unallocated_encoding(s);
+ return true;
+ }
+ gen_a64_update_pc(s, 0);
+ gen_helper_pre_smc(cpu_env, tcg_constant_i32(syn_aa64_smc(a->imm)));
+ /* Architecture requires ss advance before we do the actual work */
+ gen_ss_advance(s);
+ gen_exception_insn_el(s, 4, EXCP_SMC, syn_aa64_smc(a->imm), 3);
+ return true;
+}
+
+static bool trans_BRK(DisasContext *s, arg_i *a)
+{
+ gen_exception_bkpt_insn(s, syn_aa64_bkpt(a->imm));
+ return true;
+}
+
+static bool trans_HLT(DisasContext *s, arg_i *a)
+{
+ /*
+ * HLT. This has two purposes.
+ * Architecturally, it is an external halting debug instruction.
+ * Since QEMU doesn't implement external debug, we treat this as
+ * it is required for halting debug disabled: it will UNDEF.
+ * Secondly, "HLT 0xf000" is the A64 semihosting syscall instruction.
+ */
+ if (semihosting_enabled(s->current_el == 0) && a->imm == 0xf000) {
+ gen_exception_internal_insn(s, EXCP_SEMIHOST);
+ } else {
+ unallocated_encoding(s);
+ }
+ return true;
}
/*
@@ -14035,9 +13993,6 @@ static bool btype_destination_ok(uint32_t insn, bool bt, int btype)
static void disas_a64_legacy(DisasContext *s, uint32_t insn)
{
switch (extract32(insn, 25, 4)) {
- case 0xa: case 0xb: /* Branch, exception generation and system insns */
- disas_b_exc_sys(s, insn);
- break;
case 0x4:
case 0x6:
case 0xc:
Convert the exception generation instructions SVC, HVC, SMC, BRK and HLT to decodetree. The old decoder decoded the halting-debug insnns DCPS1, DCPS2 and DCPS3 just in order to then make them UNDEF; as with DRPS, we don't bother to decode them, but document the patterns in a64.decode. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- target/arm/tcg/a64.decode | 15 +++ target/arm/tcg/translate-a64.c | 173 ++++++++++++--------------------- 2 files changed, 79 insertions(+), 109 deletions(-)