MIPS: traps.c: Verify the ISA for microMIPS RDHWR emulation

Make sure it's the microMIPS rather than MIPS16 ISA before emulating
microMIPS RDHWR.  Mostly needed as an optimisation for configurations
where `cpu_has_mmips' is hardcoded to 0 and also a good measure in case
we add further microMIPS instructions to emulate in the future, as the
corresponding MIPS16 encoding is ADDIUSP, not supposed to trap.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12282/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Maciej W. Rozycki 2016-01-30 09:08:43 +00:00 committed by Ralf Baechle
parent 6870e707c6
commit 3d50a7fb42

View File

@ -1122,19 +1122,7 @@ no_r2_instr:
if (unlikely(compute_return_epc(regs) < 0))
goto out;
if (get_isa16_mode(regs->cp0_epc)) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
status = SIGSEGV;
opcode = mmop[0];
opcode = (opcode << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
} else {
if (!get_isa16_mode(regs->cp0_epc)) {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
@ -1149,6 +1137,18 @@ no_r2_instr:
if (status < 0)
status = simulate_fp(regs, opcode, old_epc, old31);
} else if (cpu_has_mmips) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
status = SIGSEGV;
opcode = mmop[0];
opcode = (opcode << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
}
if (status < 0)