Implement ARMv8 software single-step handling for A64 code:
correctly update the single-step state machine and generate
debug exceptions when stepping A64 code.

This patch has no behavioural change since MDSCR_EL1.SS can't
be set by the guest yet.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>

If gen_goto_tb() decides not to link the two TBs, then the
fallback path generates unnecessary code:
 * if singlestep is enabled then we generate unreachable code
   after the gen_exception_internal(EXCP_DEBUG)
 * if singlestep is disabled then we will generate exit_tb(0)
   twice, once in gen_goto_tb() and once coming out of the
   main loop with is_jmp set to DISAS_JUMP

Correct these deficiencies by only emitting exit_tb() in the
non-singlestep case, in which case we can use DISAS_TB_JUMP
to suppress the main-loop exit_tb().
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>

When we take an exception resulting from a BRK instruction,
the architecture requires that the "preferred return address"
reported to the exception handler is the address of the BRK
itself, not the following instruction (like undefined
insns, and in contrast with SVC, HVC and SMC). Follow this,
rather than incorrectly reporting the address of the following
insn.

(We do get this correct for the A32/T32 BKPT insns.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org

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

In handle_simd_shift_fpint_conv(), the combination of is_double == true,
is_scalar == false and is_q == false is an unallocated encoding; the
'both parts false' case of the nested ?: expression for calculating
maxpass is therefore unreachable and can be removed.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1402171881-14343-4-git-send-email-peter.maydell@linaro.org

In disas_simd_3same_int(), none of the instructions permit is_q
to be false with size == 3 (this would be a vector operation with
a one-element vector, and the instruction set encodes those as
scalar operations). Replace the always-true ?: check with an
assert.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1402171881-14343-3-git-send-email-peter.maydell@linaro.org

Implement the two-register SHA instruction group from the optional
Crypto Extensions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1401458125-27977-10-git-send-email-peter.maydell@linaro.org

Implement the 3-register SHA instruction group from the optional
Crypto Extensions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1401458125-27977-9-git-send-email-peter.maydell@linaro.org

Implement the AES instructions from the optional Crypto Extensions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1401458125-27977-8-git-send-email-peter.maydell@linaro.org

Implement the optional A64 CRC instructions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1401458125-27977-6-git-send-email-peter.maydell@linaro.org

Now that we have a separate ARM_FEATURE_V8_PMULL bit, use it for
the A64 PMULL, not the AES feature bit.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

These will soon require cpu_ldst.h, so move them out of cpu.h.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Rather than include helper.h with N values of GEN_HELPER, include a
secondary file that sets up the macros to include helper.h.  This
minimizes the files that must be rebuilt when changing the macros
for file N.
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NRichard Henderson <rth@twiddle.net>

Suggested-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1400980132-25949-19-git-send-email-edgar.iglesias@gmail.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

So that it can be shared with the AArch32 code.
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1400980132-25949-2-git-send-email-edgar.iglesias@gmail.com
Message-id: 1400805738-11889-5-git-send-email-edgar.iglesias@gmail.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

For linked branches, updates to the link register happen
conceptually after the read of the branch target register.
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Cc: qemu-stable@nongnu.org
Message-id: 1398926097-28097-3-git-send-email-edgar.iglesias@gmail.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Like was done for AArch32 for WFE, implement both WFE and YIELD as a
yield operation. This speeds up multi-core system emulation.
Signed-off-by: NRob Herring <rob.herring@linaro.org>
Message-id: 1397588401-20366-1-git-send-email-robherring2@gmail.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The test for the U bit was incorrectly inverted in the scalar case of SQXTUN.
This doesn't affect the vector case as the U bit is used to select XTN(2).
Reported-by: NHao Liu <hao.liu@arm.com>
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NClaudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Implement exception handling for AArch64 EL1. Exceptions from AArch64 or
AArch32 EL0 are supported.
Signed-off-by: NRob Herring <rob.herring@linaro.org>
[PMM: fixed minor style nits; updated to match changes in
 previous patches; added some of the simpler cases of
 illegal-exception-return support]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Implement the DC ZVA instruction, which clears a block of memory.
The fast path obtains a pointer to the underlying RAM via the TCG TLB
data structure so we can do a direct memset(), with fallback to a
simple byte-store loop in the slow path.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Acked-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Because unallocated encodings generate different exception syndrome
information from traps due to FP being disabled, we can't do a single
"is fp access disabled" check at a high level in the decode tree.
To help in catching bugs where the access check was forgotten in some
code path, we set this flag when the access check is done, and assert
that it is set at the point where we actually touch the FP regs.

This requires us to pass the DisasContext to the vec_reg_offset
and fp_reg_offset functions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

For the A64 instruction set, the only FP/Neon disable trap
is the CPACR FPEN bits, which may indicate "enabled", "disabled"
or "disabled for EL0". Add a bit to the AArch64 tb flags indicating
whether FP/Neon access is currently enabled and make the decoder
emit code to raise exceptions on use of FP/Neon insns if it is not.

We use a new flag in DisasContext rather than borrowing the
existing vfp_enabled flag because the A32/T32 decoder is going
to need both.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Acked-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
---
I'm aware this is a rather hard to review patch; sorry.
I have done an exhaustive check that we have fp access checks
in all code paths with the aid of the assertions added in the
next patch plus the code-coverage hack patch I posted to the
list earlier.

This patch is correct as of
09e03735 target-arm: A64: Add saturating accumulate ops (USQADD/SUQADD)
which was the last of the Neon insns to be added, so assuming
no refactoring of the code it should be fine.

Add new helpers exception_with_syndrome (for generating an exception
with syndrome information) and exception_uncategorized (for generating
an exception with "Unknown or Uncategorized Reason", which have a syndrome
register value of zero), and use them to generate the correct syndrome
information for exceptions which are raised directly from generated code.

This patch includes moving the A32/T32 gen_exception_insn functions
further up in the source file; they will be needed for "VFP/Neon disabled"
exception generation later.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

For exceptions taken to AArch64, if a coprocessor/system register
access fails due to a trap or enable bit then the syndrome information
must include details of the failing instruction (crn/crm/opc1/opc2
fields, etc). Make the decoder construct the syndrome information
at translate time so it can be passed at runtime to the access-check
helper function and used as required.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Currently cpu.h defines a mixture of functions and types needed by
the rest of QEMU and those needed only by files within target-arm/.
Split the latter out into a new header so they aren't needlessly
exposed further than required.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

The order of operands for the accumulate step in disas_simd_3same_int()
was reversed. This only affected the MLS instruction, since all the
other accumulating instructions in this category perform an addition
rather than a subtraction.
Reported-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Tested-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Add the saturating accumulate operations USQADD and SUQADD
to the A64 instruction set. This completes coverage of A64 Neon.
These operations (which are unsigned + signed -> signed and
signed + unsigned -> unsigned) don't exist in the A32/T32
instruction set, so require a complete new set of helper functions.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

This mostly re-uses the existing NEON helpers with an additional two for
the 64 bit case. I also took the opportunity to add TCG_CALL_NO_RWG
options to the helpers as they don't modify globals (saturation flags
are in the CPU Environment).
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

This adds support for [UF]RSQRTE instructions. It utilises the existing
NEON helpers with some changes. The changes include an explicit passing
of fpstatus (so the correct one is used between arm32 and aarch64),
denormilzation, more correct error handling and also proper scaling of
the fraction going into the estimate.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-25-git-send-email-peter.maydell@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Implement the FCVTXN operation, which does a narrowing fp precision
conversion using the "round to odd" (von Neumann) mode. This can
conveniently be implemented as "do operation using round to zero;
then set the LSB of the mantissa to 1 if the Inexact flag was set".
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-24-git-send-email-peter.maydell@linaro.org

This completes the set of integer narrowing saturating ops including:
     SQXTN, SQXTN2
     SQXTUN, SQXTUN2
     UQXTN, UQXTN2
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-23-git-send-email-peter.maydell@linaro.org

Move the handle_2misc_narrow() function up the file so that it can
be called from disas_simd_scalar_two_reg_misc().
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-22-git-send-email-peter.maydell@linaro.org

Implement URECPE and FRECPE instructions in both scalar and vector forms.
The actual reciprocal estimate function is shared with the A32/T32 Neon
code. However in A64 we aren't using the Neon "standard FPSCR value"
so extra checks are necessary to handle non-squashed denormal inputs
which can never happen for A32/T32. Calling conventions for the helpers
are thus modified to pass the fpst directly; we mark the helpers as
TCG_CALL_NO_RWG since we're changing the declarations anyway.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-21-git-send-email-peter.maydell@linaro.org

Implement FCVTZS and FCVTZU in the shift-imm and scalar-shift-imm
categories; this completes the implementation of those two groups.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-19-git-send-email-peter.maydell@linaro.org

Implement the saturating left shift instructions SQSHL, SQSHLU
and UQSHL for the scalar-shift-imm and shift-imm categories.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-18-git-send-email-peter.maydell@linaro.org

Implement the FRINT* round-to-integral operations from
the 2-reg-misc category.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-16-git-send-email-peter.maydell@linaro.org

Implement SRI (shift right and insert).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-15-git-send-email-peter.maydell@linaro.org

These are fairly simple exponent only estimation functions using helpers.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-14-git-send-email-peter.maydell@linaro.org

Add the remaining unsupported opcodes to the decode switches
for the shift-imm and scalar shift-imm categories so we can
see what is still to be implemented.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-13-git-send-email-peter.maydell@linaro.org

Implement FCVTL, the only instruction in the 2-reg-misc group
which widens from size to 2*size elements.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-12-git-send-email-peter.maydell@linaro.org