The OpenRISC architecture has the Power Management Register (PMR)
special purpose register to manage cpu power states. The interesting
modes are:
* Doze Mode (DME) - Stop cpu except timer & pic - wake on interrupt
* Sleep Mode (SME) - Stop cpu and all units - wake on interrupt
* Suspend Model (SUME) - Stop cpu and all units - wake on reset
The linux kernel will set DME when idle.
This patch implements the PMR SPR and halts the qemu cpu when there is a
change to DME or SME. This means that openrisc qemu in no longer peggs
a host cpu at 100%.
In order for this to work we need to kick the CPU when timers are
expired. Update the cpu timer to kick the cpu upon each timer event.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Previously serialization did not persist the tlb, timer, pic and other
key state items. This meant snapshotting and restoring a running os
would crash. After adding these I am able to take snapshots of a
running linux os and restore at a later time.
I am currently not trying to maintain capatibility with older versions
as I do not believe this really worked before or anyone used it.
Signed-off-by: Stafford Horne <shorne@gmail.com>
Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature. When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.
This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required. This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.
This is need for openrisc linux smp kernels to boot correctly.
Signed-off-by: Stafford Horne <shorne@gmail.com>
The NPC SPR is really only supposed to be used for FPGA debugging.
It contains the same contents as PC, unless one plays games. Follow
the or1ksim implementation in flushing delayed branch state when it
is changed.
The PPC SPR need not be updated every instruction, merely when we
exit the TB or attempt to read its contents.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Significantly simplifies the implementation of the use of MAC.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This avoids having to keep merging and extracting the flag from SR.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
