qemu/target-m68k
Sergey Fedorov 5b053a4a28 tcg: Clean up direct block chaining safety checks
We don't take care of direct jumps when address mapping changes. Thus we
must be sure to generate direct jumps so that they always keep valid
even if address mapping changes. Luckily, we can only allow to execute a
TB if it was generated from the pages which match with current mapping.

Document tcg_gen_goto_tb() declaration and note the reason for
destination PC limitations.

Some targets with variable length instructions allow TB to straddle a
page boundary. However, we make sure that both of TB pages match the
current address mapping when looking up TBs. So it is safe to do direct
jumps into the both pages. Correct the checks for some of those targets.

Given that, we can safely patch a TB which spans two pages. Remove the
unnecessary check in cpu_exec() and allow such TBs to be patched.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
..
cpu-qom.h target-m68k: Use cpu_exec_interrupt qom hook 2014-09-25 18:54:21 +01:00
cpu.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
cpu.h tb: consistently use uint32_t for tb->flags 2016-05-12 14:06:40 -10:00
gdbstub.c m68k: Clean up includes 2016-01-29 15:07:24 +00:00
helper.c m68k: Clean up includes 2016-01-29 15:07:24 +00:00
helper.h tcg: Invert the inclusion of helper.h 2014-05-28 09:33:54 -07:00
m68k-semi.c m68k: Clean up includes 2016-01-29 15:07:24 +00:00
Makefile.objs cpu: Introduce CPUClass::gdb_{read,write}_register() 2013-07-27 00:04:17 +02:00
op_helper.c m68k: Clean up includes 2016-01-29 15:07:24 +00:00
qregs.def cpu: Move exception_index field from CPU_COMMON to CPUState 2014-03-13 19:20:46 +01:00
translate.c tcg: Clean up direct block chaining safety checks 2016-05-12 14:06:41 -10:00