target-arm: A64: Implement MSR (immediate) instructions

Implement the MSR (immediate) instructions, which can update the
PSTATE SP and DAIF fields.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
This commit is contained in:
Peter Maydell 2014-02-26 17:20:06 +00:00
parent 4cc35614a0
commit 9cfa0b4e4c
3 changed files with 51 additions and 1 deletions

View File

@ -63,6 +63,8 @@ DEF_HELPER_2(get_cp_reg, i32, env, ptr)
DEF_HELPER_3(set_cp_reg64, void, env, ptr, i64)
DEF_HELPER_2(get_cp_reg64, i64, env, ptr)
DEF_HELPER_3(msr_i_pstate, void, env, i32, i32)
DEF_HELPER_2(get_r13_banked, i32, env, i32)
DEF_HELPER_3(set_r13_banked, void, env, i32, i32)

View File

@ -319,6 +319,31 @@ uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
return ri->readfn(env, ri);
}
void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm)
{
/* MSR_i to update PSTATE. This is OK from EL0 only if UMA is set.
* Note that SPSel is never OK from EL0; we rely on handle_msr_i()
* to catch that case at translate time.
*/
if (arm_current_pl(env) == 0 && !(env->cp15.c1_sys & SCTLR_UMA)) {
raise_exception(env, EXCP_UDEF);
}
switch (op) {
case 0x05: /* SPSel */
env->pstate = deposit32(env->pstate, 0, 1, imm);
break;
case 0x1e: /* DAIFSet */
env->daif |= (imm << 6) & PSTATE_DAIF;
break;
case 0x1f: /* DAIFClear */
env->daif &= ~((imm << 6) & PSTATE_DAIF);
break;
default:
g_assert_not_reached();
}
}
/* ??? Flag setting arithmetic is awkward because we need to do comparisons.
The only way to do that in TCG is a conditional branch, which clobbers
all our temporaries. For now implement these as helper functions. */

View File

@ -1128,7 +1128,30 @@ static void handle_sync(DisasContext *s, uint32_t insn,
static void handle_msr_i(DisasContext *s, uint32_t insn,
unsigned int op1, unsigned int op2, unsigned int crm)
{
unsupported_encoding(s, insn);
int op = op1 << 3 | op2;
switch (op) {
case 0x05: /* SPSel */
if (s->current_pl == 0) {
unallocated_encoding(s);
return;
}
/* fall through */
case 0x1e: /* DAIFSet */
case 0x1f: /* DAIFClear */
{
TCGv_i32 tcg_imm = tcg_const_i32(crm);
TCGv_i32 tcg_op = tcg_const_i32(op);
gen_a64_set_pc_im(s->pc - 4);
gen_helper_msr_i_pstate(cpu_env, tcg_op, tcg_imm);
tcg_temp_free_i32(tcg_imm);
tcg_temp_free_i32(tcg_op);
s->is_jmp = DISAS_UPDATE;
break;
}
default:
unallocated_encoding(s);
return;
}
}
static void gen_get_nzcv(TCGv_i64 tcg_rt)