target-arm: Implement AArch64 TLB invalidate ops

Implement the AArch64 TLB invalidate operations. This is
the full set of TLBI ops defined for a CPU which doesn't
implement EL2 or EL3.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: Implement AArch64 dummy MDSCR_EL1

We don't support letting the guest do debug, but Linux prods the
monitor debug system control register anyway, so implement a dummy
RAZ/WI version.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 memory attribute registers

Implement the AArch64 memory attribute registers. Since QEMU doesn't
model caches it does not need to care about memory attributes at all,
and we can simply make these read-as-written.

We did not previously implement the AArch32 versions of the MAIR
registers, which went unnoticed because of the overbroad TLB_LOCKDOWN
reginfo definition; provide them now to keep the 64<->32 register
relationship clear.

We already provided AMAIR registers for 32 bit as simple RAZ/WI;
extend that to provide a 64 bit RAZ/WI AMAIR_EL1.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 SCTLR_EL1

Implement the AArch64 view of the system control register SCTLR_EL1.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 TCR_EL1

Implement the AArch64 TCR_EL1, which is the 64 bit view of
the AArch32 TTBCR. (The uses of the bits in the register are
completely different, but in any given situation the CPU will
always interpret them one way or the other. In fact for QEMU EL1
is always 64 bit, but we share the state field because this
is the correct mapping to permit a future implementation of EL2.)
We also make the AArch64 view the 'master' as far as migration
and reset is concerned.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 VBAR_EL1

Implement the A64 view of the VBAR system register.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 TTBR*

Implement the AArch64 TTBR* registers. For v7 these were already 64 bits
to handle LPAE, but implemented as two separate uint32_t fields.
Combine them into a single uint64_t which can be used for all purposes.
Since this requires touching every use, take the opportunity to rename
the field to the architectural name.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 MPIDR

Implement the AArch64 MPIDR system register.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 generic timers

Implement the AArch64 view of the generic timer system registers.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: Implement AArch64 ID and feature registers

Implement the AArch64-specific ID and feature registers. Although
many of these are currently not used by the architecture (and so
always zero for all implementations), we define the full set of
fields in the ARMCPU struct for symmetry.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 dummy breakpoint and watchpoint registers

In AArch64 the breakpoint and watchpoint registers are mandatory, so the
kernel always accesses them on bootup. Implement dummy versions, which
read as written but have no actual effect.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 OSLAR_EL1 sysreg as WI

Define a dummy version of the AArch64 OSLAR_EL1 system register
which just ignores writes. Linux will always write to this (it
is the OS lock used for debugging), but we don't support debug.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Get MMU index information correct for A64 code

Emit the correct MMU index information for loads and stores from
A64 code, rather than hardwiring it to "always kernel mode",
by storing the exception level in the TB flags, and make
cpu_mmu_index() return the right answer when the CPU is in
AArch64 mode.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: A64: Implement WFI

Implement the WFI instruction for A64; this just involves wiring
up the instruction, and adding a gen_a64_set_pc_im() which was
accidentally omitted from the A64 decoder top loop.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: Store AIF bits in env->pstate for AArch32

To avoid complication in code that otherwise would not need to
care about whether EL1 is AArch32 or AArch64, we should store
the interrupt mask bits (CPSR.AIF in AArch32 and PSTATE.DAIF
in AArch64) in one place consistently regardless of EL1's mode.
Since AArch64 has an extra enable bit (D for debug exceptions)
which isn't visible in AArch32, this means we need to keep
the enables in env->pstate. (This is also consistent with the
general approach we're taking that we handle 32 bit CPUs as
being like AArch64/ARMv8 CPUs but which only run in 32 bit mode.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
target-arm: Implement AArch64 DAIF system register

Implement the DAIF system register which is a view of the
DAIF bits in PSTATE.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: A64: Implement MSR (immediate) instructions

Implement the MSR (immediate) instructions, which can update the
PSTATE SP and DAIF fields.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Implement AArch64 view of CPACR

Implement the AArch64 view of the CPACR. The AArch64
CPACR is defined to have a lot of RES0 bits, but since
the architecture defines that RES0 bits may be implemented
as reads-as-written and we know that a v8 CPU will have
no registered coprocessors for cp0..cp13 we can safely
implement the whole register this way.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Add utility function for checking AA32/64 state of an EL

There are various situations where we need to behave differently
depending on whether a given exception level is in AArch64 or
AArch32 state. The state of the current exception level is stored
in env->aarch64, but there's no equivalent guest-visible architected
state bits for the status of the exception levels "above" the
current one which may still affect execution. At the moment we
only support EL1 (ie no EL2 or EL3) and insist that AArch64
capable CPUs run with EL1 in AArch64 state, but these may change
in the future, so abstract out the "what state is this?" check
into a utility function which can be enhanced later if necessary.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
target-arm: Define exception record for AArch64 exceptions

For AArch32 exceptions, the only information provided about
the cause of an exception is the individual exception type (data
abort, undef, etc), which we store in env->exception_index. For
AArch64, the CPU provides much more detail about the cause of
the exception, which can be found in the syndrome register.
Create a set of fields in CPUARMState which must be filled in
whenever an exception is raised, so that exception entry can
correctly fill in the syndrome register for the guest.
This includes the information which in AArch32 appears in
the DFAR and IFAR (fault address registers) and the DFSR
and IFSR (fault status registers) for data aborts and
prefetch aborts, since if we end up taking the MMU fault
to AArch64 rather than AArch32 this will need to end up
in different system registers.

This patch does a refactoring which moves the setting of the
AArch32 DFAR/DFSR/IFAR/IFSR from the point where the exception
is raised to the point where it is taken. (This is no change
for cores with an MMU, retains the existing clearly incorrect
behaviour for ARM946 of trashing the MP access permissions
registers which share the c5_data and c5_insn state fields,
and has no effect for v7M because we don't implement its
MPU fault status or address registers.)

As a side effect of the cleanup we fix a bug in the AArch64
linux-user mode code where we were passing a 64 bit fault
address through the 32 bit c6_data/c6_insn fields: it now
goes via the always-64-bit exception.vaddress.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>