target/hppa: Raise exception 26 on emulated hardware

target/hppa: Raise exception 26 on emulated hardware

On PCXS chips (PA7000, pa 1.1a), trap #18 is raised on memory faults,
while all later chips (>= PA7100) generate either trap #26, #27 or #28
(depending on the fault type).

Since the current qemu emulation emulates a B160L machine (with a
PA7300LC PCX-L2 chip, we should raise trap #26 (EXCP_DMAR) instead
of #18 (EXCP_DMP) on access faults by the Linux kernel to page zero.

With the patch we now get the correct output (I tested against real
hardware):
 Kernel Fault: Code=26 (Data memory access rights trap)
instead of:
 Kernel Fault: Code=18 (Data memory protection/unaligned access trap)

Signed-off-by: Helge Deller <[email protected]>
Message-Id: <20181007205153[email protected]>
Signed-off-by: Richard Henderson <[email protected]>