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>
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>
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>
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>
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>
Stafford Horne
Tim 'mithro' Ansell
Richard Henderson
Alex Bennée
Thomas Huth