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>
The features property has stored the exact same thing as the cpucfgr
spr. Remove the feature enum and property as it is not needed.
In order to preserve the behavior or keeping features accross reset this
patch moves cpucfgr into the non reset region of the state struct. Since
the cpucfgr is read only this means we only need to sset cpucfgr once
during class init.
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>
These are used to identify the processor in SMP system. Their
definition has been defined in verilog cores but it not yet part of the
spec but it will be soon.
The proposal for this is available:
https://openrisc.io/proposals/core-identifier-and-number-of-cores
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Stafford Horne <shorne@gmail.com>
When debugging in gdb you might want to inspect instructions in mapped
pages or in exception vectors like 0x800 etc. This was previously not
possible in qemu since the *get_phys_page_debug() routine only looked
into the data tlb.
Change to fall back to look into instruction tlb and plain physical
pages.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Exception Prefix High (EPH) control bit of the Supervision Register
(SR).
The significant bits (31-12) of the vector offset address for each
exception depend on the setting of the Supervision Register (SR)'s EPH
bit and the Exception Vector Base Address Register (EVBAR).
If SR[EPH] is set, the vector offset is logically ORed with the offset
0xF0000000.
This means if EPH is;
* 0 - Exceptions vectors start at EVBAR
* 1 - Exception vectors start at EVBAR | 0xF0000000
Signed-off-by: Tim 'mithro' Ansell <mithro@mithis.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Exception Vector Base Address Register (EVBAR) - This optional register
can be used to apply an offset to the exception vector addresses.
The significant bits (31-12) of the vector offset address for each
exception depend on the setting of the Supervision Register (SR)'s EPH
bit and the Exception Vector Base Address Register (EVBAR).
Its presence is indicated by the EVBARP bit in the CPU Configuration
Register (CPUCFGR).
Signed-off-by: Tim 'mithro' Ansell <mithro@mithis.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
The HW does not special-case r0, but the ABI specifies that r0 should
contain 0. If we expose this fact to the optimizer, we can simplify
a lot of the generated code. We must of course verify that r0==0, but
that is trivial to do with a TB flag.
Signed-off-by: Richard Henderson <rth@twiddle.net>
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>
This allows the tcg optimizer to see, and fold, all of the
constants involved in a GOT base register load sequence.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Note that the specification for lf.madd.s is confused. It's
the only mention of supposed FPMADDHI/FPMADDLO special registers.
On the other hand, or1ksim implements a somewhat normal non-fused
multiply and add. Mirror that.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
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>
Not documented as disabled for user mode.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
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>
Decoding the opcodes in the right order reduces by 100+ lines.
Also, it happens to put the opcodes in the same order as Chapter 17.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Fix incorrect overflow calculation. Move overflow exception check
to a helper function, to eliminate inline branches. Remove some
incorrect special casing of R0. Implement multiply inline.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The architecture manual is consistent in using "I" for signed
fields and "K" for unsigned fields. Mirror that.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Avoids warnings from unused variables etc.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
I am working on testing instruction emulation patches for the linux
kernel. During testing I found these 2 issues:
- sets DSX (delay slot exception) but never clears it
- EEAR for illegal insns should point to the bad exception (as per
openrisc spec) but its not
This patch fixes these two issues by clearing the DSX flag when not in a
delay slot and by setting EEAR to exception PC when handling illegal
instruction exceptions.
After this patch the openrisc kernel with latest patches boots great on
qemu and instruction emulation works.
Cc: qemu-trivial@nongnu.org
Cc: openrisc@lists.librecores.org
Signed-off-by: Stafford Horne <shorne@gmail.com>
Message-Id: <20170113220028.29687-1-shorne@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We have never has the concept of global TLB entries which would avoid
the flush so we never actually use this flag. Drop it and make clear
that tlb_flush is the sledge-hammer it has always been.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
[DG: ppc portions]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
It is a common thing amongst the various cpu reset functions want to
flush the SoftMMU's TLB entries. This is done either by calling
tlb_flush directly or by way of a general memset of the CPU
structure (sometimes both).
This moves the tlb_flush call to the common reset function and
additionally ensures it is only done for the CONFIG_SOFTMMU case and
when tcg is enabled.
In some target cases we add an empty end_of_reset_fields structure to the
target vCPU structure so have a clear end point for any memset which
is resetting value in the structure before CPU_COMMON (where the TLB
structures are).
While this is a nice clean-up in general it is also a precursor for
changes coming to cputlb for MTTCG where the clearing of entries
can't be done arbitrarily across vCPUs. Currently the cpu_reset
function is usually called from the context of another vCPU as the
architectural power up sequence is run. By using the cputlb API
functions we can ensure the right behaviour in the future.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
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>
