KScratch<n> Registers (CP0 Register 31, Selects 2 to 7)

The KScratch registers are read/write registers available for scratch pad
storage by kernel mode software. They are 32-bits in width for 32-bit
processors and 64-bits for 64-bit processors.

CP0Config4.KScrExist[2:7] bits indicate presence of CP0_KScratch1-6 registers.
For Release 6, all KScratch registers are required.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NYongbok Kim <yongbok.kim@imgtec.com>

Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Message-id: 1413982829-27225-1-git-send-email-leon.alrae@imgtec.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Remove the functions gen_load_ACX and gen_store_ACX, which appear to have
been unused since they were first introduced many years ago. These functions
were the only places using the cpu_ACX[] array of TCG globals, so remove
that and its accompanying regnames_ACX[] as well.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

Add ifdef TARGET_MIPS64 guards around various functions that are only
called from helpers for TARGET_MIPS64 CPUs; this avoids compiler
warnings when building other configs.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

The function check_mips64() is only used if TARGET_MIPS64 is defined;
add an ifdef guard to its definition to avoid warnings about it being
unused in other configurations.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

The do_lbu() function defined by the expansion of HELPER_LD() is
never used, so don't define it.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

The function get_DSPControl_24() is unused; remove it.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

Commit 240ce26a broke MIPS16 and microMIPS support as it didn't
care those branches and jumps don't have delay slot in
MIPS16 and microMIPS.

This patch introduces a new argument delayslot_size to the
gen_compute_branch() indicating size of delay slot {0, 2, 4}.
And the information is used to call handle_delay_slot() forcingly
when no delay slot is required.

There are some microMIPS branch and jump instructions that requires
exact size of instruction in the delay slot. For indicating
these instructions, MIPS_HFLAG_BDS_STRICT flag is introduced.

Those fictional branch opcodes defined to support MIPS16 and
microMIPS are no longer needed.
Signed-off-by: NYongbok Kim <yongbok.kim@imgtec.com>
Tested-by: NJonas Gorski <jogo@openwrt.org>
Reviewed-by: NLeon Alrae <leon.alrae@imgtec.com>
[leon.alrae@imgtec.com: cosmetic changes]
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

Update OPC_SYNCI with BS_STOP, in order to handle the instructions which saved
in the same TB of the store instruction.
Signed-off-by: NDongxue Zhang <elta.era@gmail.com>
Reviewed-by: NYongbok Kim <yongbok.kim@imgtec.com>
[leon.alrae@imgtec.com: update microMIPS SYNCI as well]
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NYongbok Kim <yongbok.kim@imgtec.com>

Signed-off-by: NYongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

Status.FR bit must be ignored on write and read as 1 when an implementation of
Release 6 of the Architecture in which a 64-bit floating point unit is
implemented.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NYongbok Kim <yongbok.kim@imgtec.com>

Signed-off-by: NYongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

In terms of encoding MIPS32R6 MIN.fmt, MAX.fmt, MINA.fmt, MAXA.fmt replaced
MIPS-3D RECIP1, RECIP2, RSQRT1, RSQRT2 instructions.

In R6 all Floating Point instructions are supposed to be IEEE-2008 compliant
i.e. FIR.HAS2008 always 1. However, QEMU softfloat for MIPS has not been
updated yet.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NYongbok Kim <yongbok.kim@imgtec.com>

Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NYongbok Kim <yongbok.kim@imgtec.com>

Introduce MIPS32R6 Compact Branch instructions which do not have delay slot -
they have forbidden slot instead. However, current implementation does not
support forbidden slot yet.

Add also BC1EQZ and BC1NEZ instructions.
Signed-off-by: NYongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

Signed-off-by: NYongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

In R6 the special behaviour for data references is also specified for Kernel
and Supervisor mode. Therefore MIPS_HFLAG_UX is replaced by generic
MIPS_HFLAG_AWRAP indicating enabled 32-bit address wrapping.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

Also consider OPC_SPIM instruction as deleted in R6 because it is overlaping
with MIPS32R6 SDBBP.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

Use "R6_" prefix in front of all new Multiply / Divide instructions for
easier differentiation between R6 and preR6.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

The encoding of PREF, CACHE, LLD and SCD instruction changed in MIPS32R6.
Additionally, the hint codes in PREF instruction greater than or
equal to 24 generate Reserved Instruction Exception.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

Move DSP and Loongson instruction to *_legacy functions as they have been
removed in R6.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

For better code readability and to avoid 'if' statements for all R6 and preR6
instructions whose opcodes are the same - decode_opc_special* functions are
split into functions with _r6 and _legacy suffixes.

*_r6 functions will contain instructions which were introduced in R6.
*_legacy functions will contain instructions which were removed in R6.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

Creating separate decode functions for special, special2 and special3
instructions to ease adding new R6 instructions and removing legacy
instructions.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

The encoding of LL and SC instruction has changed in MIPS32 Release 6.
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>

Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>

Signal Reserved Instruction Exception on instructions that do not exist in R6.
In this commit the following groups of preR6 instructions are marked as deleted:
- Floating Point Paired Single
- Floating Point Compare
- conditional moves / branches on FPU conditions
- branch likelies
- unaligned loads / stores
- traps
- legacy accumulator instructions
- COP1X
- MIPS-3D
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>

GDB assumes that watchpoint set via the gdbstub remote protocol will
behave in the same way as hardware watchpoints for the target. In
particular, whether the CPU stops with the PC before or after the insn
which triggers the watchpoint is target dependent. Allow guest CPU
code to specify which behaviour to use. This fixes a bug where with
guest CPUs which stop before the accessing insn GDB would manually
step forward over what it thought was the insn and end up one insn
further forward than it should be.

We set this flag for the CPU architectures which set
gdbarch_have_nonsteppable_watchpoint in gdb 7.7:
ARM, CRIS, LM32, MIPS and Xtensa.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: NMax Filippov <jcmvbkbc@gmail.com>
Tested-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Michael Walle <michael@walle.cc> (for lm32)
Message-id: 1410545057-14014-1-git-send-email-peter.maydell@linaro.org

Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Reviewed-by: NLeon Alrae <leon.alrae@imgtec.com>
Tested-by: NLeon Alrae <leon.alrae@imgtec.com>
Message-id: 1410626734-3804-19-git-send-email-rth@twiddle.net
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

MIPS registers an unassigned access handler which raises a guest bus
error exception. However this causes QEMU to crash when KVM is enabled
as it isn't called from the main execution loop so longjmp() gets called
without a corresponding setjmp().

Until the KVM API can be updated to trigger a guest exception in
response to an MMIO exit, prevent the bus error exception being raised
from mips_cpu_unassigned_access() if KVM is enabled.

The check is at run time since the do_unassigned_access callback is
initialised before it is known whether KVM will be enabled.

The problem can be triggered with Malta emulation by making the guest
write to the reset region at physical address 0x1bf00000, since it is
marked read-only which is treated as unassigned for writes.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Free t0 and t1 in opcode OPC_DINSV.
Signed-off-by: NDongxue Zhang <elta.era@gmail.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

KVM doesn't yet support the MIPS FPU, or writing to the guest's Config1
register which contains the FPU implemented bit. Clear QEMU's version of
that bit on reset and display a warning that the FPU has been disabled.

The previous incorrect Config1 CP0 register value wasn't being passed to
KVM yet, however we should ensure it is set correctly now to reduce the
risk of breaking migration/loadvm to a future version of QEMU/Linux that
does support it.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The EBase CP0 register is initialised to 0x80000000, however with KVM
the guest's KSEG0 is at 0x40000000. The incorrect value doesn't get
passed to KVM yet as KVM doesn't implement the EBase register, however
we should set it correctly now so as not to break migration/loadvm to a
future version of QEMU that does support EBase.

Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

In order to avoid access to the CPUMIPSState structure in the
translator, keep a copy of CP0_Config1 into DisasContext. The whole
register is read-only so it can be copied as a single value.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

From MIPS documentation (Volume III):

UserLocal Register (CP0 Register 4, Select 2)
Compliance Level: Recommended.

The UserLocal register is a read-write register that is not interpreted by
the hardware and conditionally readable via the RDHWR instruction.

This register only exists if the Config3-ULRI register field is set.

Privileged software may write this register with arbitrary information and
make it accessible to unprivileged software via register 29 (ULR) of the
RDHWR instruction. To do so, bit 29 of the HWREna register must be set to a
1 to enable unprivileged access to the register.
Signed-off-by: NPetar Jovanovic <petar.jovanovic@imgtec.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Enable KVM support for MIPS in the build system.
Signed-off-by: NSanjay Lal <sanjayl@kymasys.com>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When KVM is enabled call kvm_mips_reset_vcpu() from mips_cpu_reset() as
done for other targets since commit 50a2c6e5 (kvm: reset state from
the CPU's reset method).
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Implement the main KVM arch API for MIPS.
Signed-off-by: NSanjay Lal <sanjayl@kymasys.com>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>