Commit graph

3 commits

Author SHA1 Message Date
Peter Maydell 79ca0b299a
m68k: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Backports commit d8416665774bb6c057cbb3dd67d802e67e7a03ef from qemu
2018-02-19 01:06:05 -05:00
Greg Ungerer 1f6f6b2863
m68k: fix usp processing on interrupt entry and exception exit
The action to potentially switch sp register is not occurring at the correct
point in the interrupt entry or exception exit sequences.

For the interrupt entry case the sp on entry is used to create the stack
exception frame - but this may well be the user stack pointer, since we
haven't done the switch yet. Re-order the flow to switch the sp regs then
use the current sp to create the exception frame.

For the return from exception case the code is unwinding the sp after
switching sp registers. But it should always unwind the supervisor sp
first, then carry out any required sp switch.

Note that these problems don't effect operation unless the user sp bit is
set in the CACR register. Only a single sp is used in the default power up
state. Previously Linux only used this single sp mode. But modern versions
of Linux use the user sp mode now, so we need correct behavior for Linux
to work.

Backports commit 0c8ff723bd29e5c8b2ca989f857ae5c37ec49c4e from qemu
2018-02-17 15:23:09 -05:00
Nguyen Anh Quynh 344d016104 import 2015-08-21 15:04:50 +08:00