Commit Graph

272 Commits

Author SHA1 Message Date
Richard Henderson 1efdd407a2 target/arm: Convert Synchronization primitives
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-22-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 5e291fe168 target/arm: Convert load/store (register, immediate, literal)
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 145952e87f target/arm: Convert T32 ADDW/SUBW
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 2cde9ea57d target/arm: Convert the rest of A32 Miscelaneous instructions
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-19-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson ef11bc3c46 target/arm: Convert ERET
Pass the T5 encoding of SUBS PC, LR, #IMM through the normal SUBS path
to make it clear exactly what's happening -- we hit ALUExceptionReturn
along that path.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-18-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 4c97f5b2f0 target/arm: Convert CLZ
Document our choice about the T32 CONSTRAINED UNPREDICTABLE behaviour.
This matches the undocumented choice made by the legacy decoder.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 4ed95abd70 target/arm: Convert BX, BXJ, BLX (register)
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-16-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 6c35d53f1b target/arm: Convert Cyclic Redundancy Check
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson d0b2664450 target/arm: Convert MRS/MSR (banked, register)
The m-profile and a-profile decodings overlap.  Only return false
for the case of wrong profile; handle UNDEFINED for permission failure
directly.  This ensures that we don't accidentally pass an insn that
applies to the wrong profile.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 6313059623 target/arm: Convert MSR (immediate) and hints
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 485b607d4f target/arm: Simplify op_smlawx for SMLAW*
By shifting the 16-bit input left by 16, we can align the desired
portion of the 48-bit product and use tcg_gen_muls2_i32.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson ea96b37464 target/arm: Simplify op_smlaxxx for SMLAL*
Since all of the inputs and outputs are i32, dispense with
the intermediate promotion to i64 and use tcg_gen_add2_i32.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 26c6923de7 target/arm: Convert Halfword multiply and multiply accumulate
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 6d0730a824 target/arm: Convert Saturating addition and subtraction
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 2409d56454 target/arm: Simplify UMAAL
Since all of the inputs and outputs are i32, dispense with
the intermediate promotion to i64 and use tcg_gen_mulu2_i32
and tcg_gen_add2_i32.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson bd92fe353b target/arm: Convert multiply and multiply accumulate
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 581c6ebd17 target/arm: Convert Data Processing (immediate)
Convert the modified immediate form of the data processing insns.
For A32, we can finally remove any code that was intertwined with
the register and register-shifted-register forms.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 5be2c12337 target/arm: Convert Data Processing (reg-shifted-reg)
Convert the register shifted by register form of the data
processing insns.  For A32, we cannot yet remove any code
because the legacy decoder intertwines the immediate form.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 25ae32c558 target/arm: Convert Data Processing (register)
Convert the register shifted by immediate form of the data
processing insns.  For A32, we cannot yet remove any code
because the legacy decoder intertwines the reg-shifted-reg
and immediate forms.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 51409b9e8c target/arm: Add stubs for aa32 decodetree
Add the infrastructure that will become the new decoder.
No instructions adjusted so far.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Richard Henderson 69be3e1376 target/arm: Use store_reg_from_load in thumb2 code
This function already includes the test for an interworking write
to PC from a load.  Change the T32 LDM implementation to match the
A32 LDM implementation.

For LDM, the reordering of the tests does not change valid
behaviour because the only case that differs is has rn == 15,
which is UNPREDICTABLE.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-05 13:23:03 +01:00
Peter Maydell 9de65783e1 Allow page table bit to swap endianness.
Reorganize watchpoints out of i/o path.
 Return host address from probe_write / probe_access.
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Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20190903' into staging

Allow page table bit to swap endianness.
Reorganize watchpoints out of i/o path.
Return host address from probe_write / probe_access.

# gpg: Signature made Tue 03 Sep 2019 16:47:50 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth/tags/pull-tcg-20190903: (36 commits)
  tcg: Factor out probe_write() logic into probe_access()
  tcg: Make probe_write() return a pointer to the host page
  s390x/tcg: Pass a size to probe_write() in do_csst()
  hppa/tcg: Call probe_write() also for CONFIG_USER_ONLY
  mips/tcg: Call probe_write() for CONFIG_USER_ONLY as well
  tcg: Enforce single page access in probe_write()
  tcg: Factor out CONFIG_USER_ONLY probe_write() from s390x code
  s390x/tcg: Fix length calculation in probe_write_access()
  s390x/tcg: Use guest_addr_valid() instead of h2g_valid() in probe_write_access()
  tcg: Check for watchpoints in probe_write()
  cputlb: Handle watchpoints via TLB_WATCHPOINT
  cputlb: Remove double-alignment in store_helper
  cputlb: Fix size operand for tlb_fill on unaligned store
  exec: Factor out cpu_watchpoint_address_matches
  cputlb: Fold TLB_RECHECK into TLB_INVALID_MASK
  exec: Factor out core logic of check_watchpoint()
  exec: Move user-only watchpoint stubs inline
  target/sparc: sun4u Invert Endian TTE bit
  target/sparc: Add TLB entry with attributes
  cputlb: Byte swap memory transaction attribute
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-04 16:29:18 +01:00
Tony Nguyen 14776ab5a1 tcg: TCGMemOp is now accelerator independent MemOp
Preparation for collapsing the two byte swaps, adjust_endianness and
handle_bswap, along the I/O path.

Target dependant attributes are conditionalized upon NEED_CPU_H.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <81d9cd7d7f5aaadfa772d6c48ecee834e9cf7882.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:38 -07:00
Peter Maydell 5e5584c89f target/arm: Don't abort on M-profile exception return in linux-user mode
An attempt to do an exception-return (branch to one of the magic
addresses) in linux-user mode for M-profile should behave like
a normal branch, because linux-user mode is always going to be
in 'handler' mode. This used to work, but we broke it when we added
support for the M-profile security extension in commit d02a8698d7.

In that commit we allowed even handler-mode calls to magic return
values to be checked for and dealt with by causing an
EXCP_EXCEPTION_EXIT exception to be taken, because this is
needed for the FNC_RETURN return-from-non-secure-function-call
handling. For system mode we added a check in do_v7m_exception_exit()
to make any spurious calls from Handler mode behave correctly, but
forgot that linux-user mode would also be affected.

How an attempted return-from-non-secure-function-call in linux-user
mode should be handled is not clear -- on real hardware it would
result in return to secure code (not to the Linux kernel) which
could then handle the error in any way it chose. For QEMU we take
the simple approach of treating this erroneous return the same way
it would be handled on a CPU without the security extensions --
treat it as a normal branch.

The upshot of all this is that for linux-user mode we should never
do any of the bx_excret magic, so the code change is simple.

This ought to be a weird corner case that only affects broken guest
code (because Linux user processes should never be attempting to do
exception returns or NS function returns), except that the code that
assigns addresses in RAM for the process and stack in our linux-user
code does not attempt to avoid this magic address range, so
legitimate code attempting to return to a trampoline routine on the
stack can fall into this case. This change fixes those programs,
but we should also look at restricting the range of memory we
use for M-profile linux-user guests to the area that would be
real RAM in hardware.

Cc: qemu-stable@nongnu.org
Reported-by: Christophe Lyon <christophe.lyon@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20190822131534.16602-1-peter.maydell@linaro.org
Fixes: https://bugs.launchpad.net/qemu/+bug/1840922
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-03 16:20:35 +01:00
Richard Henderson e0a0c8322b target/arm: Fix SMMLS argument order
The previous simplification got the order of operands to the
subtraction wrong.  Since the 64-bit product is the subtrahend,
we must use a 64-bit subtract to properly compute the borrow
from the low-part of the product.

Fixes: 5f8cd06ebc ("target/arm: Simplify SMMLA, SMMLAR, SMMLS, SMMLSR")
Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190829013258.16102-1-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-03 16:20:34 +01:00
Peter Maydell 37ff584c15 target/arm: Allow ARMCPRegInfo read/write functions to throw exceptions
Currently the only part of an ARMCPRegInfo which is allowed to cause
a CPU exception is the access function, which returns a value indicating
that some flavour of UNDEF should be generated.

For the ATS system instructions, we would like to conditionally
generate exceptions as part of the writefn, because some faults
during the page table walk (like external aborts) should cause
an exception to be raised rather than returning a value.

There are several ways we could do this:
 * plumb the GETPC() value from the top level set_cp_reg/get_cp_reg
   helper functions through into the readfn and writefn hooks
 * add extra readfn_with_ra/writefn_with_ra hooks that take the GETPC()
   value
 * require the ATS instructions to provide a dummy accessfn,
   which serves no purpose except to cause the code generation
   to emit TCG ops to sync the CPU state
 * add an ARM_CP_ flag to mark the ARMCPRegInfo as possibly
   throwing an exception in its read/write hooks, and make the
   codegen sync the CPU state before calling the hooks if the
   flag is set

This patch opts for the last of these, as it is fairly simple
to implement and doesn't require invasive changes like updating
the readfn/writefn hook function prototype signature.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20190816125802.25877-2-peter.maydell@linaro.org
2019-09-03 16:20:34 +01:00
Richard Henderson 1ce21ba1ea target/arm: Factor out unallocated_encoding for aarch32
Make this a static function private to translate.c.
Thus we can use the same idiom between aarch64 and aarch32
without actually sharing function implementations.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190826151536.6771-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-03 16:20:34 +01:00
Richard Henderson 429a71d67e Revert "target/arm: Use unallocated_encoding for aarch32"
This reverts commit 3cb3663715.

Despite the fact that the text for the call to gen_exception_insn
is identical for aarch64 and aarch32, the implementation inside
gen_exception_insn is totally different.

This fixes exceptions raised from aarch64.

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190826151536.6771-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-03 16:20:34 +01:00
Pavel Dovgalyuk 9e9b10c649 icount: remove unnecessary gen_io_end calls
Prior patch resets can_do_io flag at the TB entry. Therefore there is no
need in resetting this flag at the end of the block.
This patch removes redundant gen_io_end calls.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <156404429499.18669.13404064982854123855.stgit@pasha-Precision-3630-Tower>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@gmail.com>
2019-08-20 17:26:22 +02:00
Richard Henderson 664b7e3b97 target/arm: Use tcg_gen_extrh_i64_i32 to extract the high word
Separate shift + extract low will result in one extra insn
for hosts like RISC-V, MIPS, and Sparc.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-8-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:53 +01:00
Richard Henderson 5f8cd06ebc target/arm: Simplify SMMLA, SMMLAR, SMMLS, SMMLSR
All of the inputs to these instructions are 32-bits.  Rather than
extend each input to 64-bits and then extract the high 32-bits of
the output, use tcg_gen_muls2_i32 and other 32-bit generator functions.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-7-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:53 +01:00
Richard Henderson adefba76e8 target/arm: Use tcg_gen_rotri_i32 for gen_swap_half
Rotate is the more compact and obvious way to swap 16-bit
elements of a 32-bit word.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:53 +01:00
Richard Henderson dd861b3f29 target/arm: Use ror32 instead of open-coding the operation
The helper function is more documentary, and also already
handles the case of rotate by zero.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:53 +01:00
Richard Henderson 464eaa9571 target/arm: Remove redundant shift tests
The immediate shift generator functions already test for,
and eliminate, the case of a shift by zero.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-4-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:52 +01:00
Richard Henderson d1f8755fc9 target/arm: Use tcg_gen_deposit_i32 for PKHBT, PKHTB
Use deposit as the composit operation to merge the
bits from the two inputs.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:52 +01:00
Richard Henderson 191f4bfe8d target/arm: Use tcg_gen_extract_i32 for shifter_out_im
Extract is a compact combination of shift + and.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:51 +01:00
Richard Henderson 640581a06d target/arm: Remove helper_double_saturate
Replace x = double_saturate(y) with x = add_saturate(y, y).
There is no need for a separate more specialized helper.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:50 +01:00
Richard Henderson 3cb3663715 target/arm: Use unallocated_encoding for aarch32
Promote this function from aarch64 to fully general use.
Use it to unify the code sequences for generating illegal
opcode exceptions.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:50 +01:00
Richard Henderson 06bcbda3f6 target/arm: Remove offset argument to gen_exception_bkpt_insn
Unlike the other more generic gen_exception{,_internal}_insn
interfaces, breakpoints always refer to the current instruction.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:50 +01:00
Richard Henderson aee828e754 target/arm: Replace offset with pc in gen_exception_internal_insn
The offset is variable depending on the instruction set.
Passing in the actual value is clearer in intent.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:50 +01:00
Richard Henderson a767fac802 target/arm: Replace offset with pc in gen_exception_insn
The offset is variable depending on the instruction set, whereas
we have stored values for the current pc and the next pc.  Passing
in the actual value is clearer in intent.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:50 +01:00
Richard Henderson a04159166b target/arm: Replace s->pc with s->base.pc_next
We must update s->base.pc_next when we return from the translate_insn
hook to the main translator loop.  By incrementing s->base.pc_next
immediately after reading the insn word, "pc_next" contains the address
of the next instruction throughout translation.

All remaining uses of s->pc are referencing the address of the next insn,
so this is now a simple global replacement.  Remove the "s->pc" field.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:49 +01:00
Richard Henderson 4818c3743b target/arm: Remove redundant s->pc & ~1
The thumb bit has already been removed from s->pc, and is always even.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:49 +01:00
Richard Henderson 16e0d8234e target/arm: Introduce add_reg_for_lit
Provide a common routine for the places that require ALIGN(PC, 4)
as the base address as opposed to plain PC.  The two are always
the same for A32, but the difference is meaningful for thumb mode.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:49 +01:00
Richard Henderson fdbcf6329d target/arm: Introduce read_pc
We currently have 3 different ways of computing the architectural
value of "PC" as seen in the ARM ARM.

The value of s->pc has been incremented past the current insn,
but that is all.  Thus for a32, PC = s->pc + 4; for t32, PC = s->pc;
for t16, PC = s->pc + 2.  These differing computations make it
impossible at present to unify the various code paths.

With the newly introduced s->pc_curr, we can compute the correct
value for all cases, using the formula given in the ARM ARM.

This changes the behaviour for load_reg() and load_reg_var()
when called with reg==15 from a 32-bit Thumb instruction:
previously they would have returned the incorrect value
of pc_curr + 6, and now they will return the architecturally
correct value of PC, which is pc_curr + 4. This will not
affect well-behaved guest software, because all of the places
we call these functions from T32 code are instructions where
using r15 is UNPREDICTABLE. Using the architectural PC value
here is more consistent with the T16 and A32 behaviour.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-4-richard.henderson@linaro.org
[PMM: added commit message note about UNPREDICTABLE T32 cases]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:49 +01:00
Richard Henderson 43722a6d4f target/arm: Introduce pc_curr
Add a new field to retain the address of the instruction currently
being translated.  The 32-bit uses are all within subroutines used
by a32 and t32.  This will become less obvious when t16 support is
merged with a32+t32, and having a clear definition will help.

Convert aarch64 as well for consistency.  Note that there is one
instance of a pre-assert fprintf that used the wrong value for the
address of the current instruction.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:49 +01:00
Richard Henderson 331b1ca616 target/arm: Pass in pc to thumb_insn_is_16bit
This function is used in two different contexts, and it will be
clearer if the function is given the address to which it applies.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 14:02:49 +01:00
Peter Maydell 8bd587c106 target/arm: Fix routing of singlestep exceptions
When generating an architectural single-step exception we were
routing it to the "default exception level", which is to say
the same exception level we execute at except that EL0 exceptions
go to EL1. This is incorrect because the debug exception level
can be configured by the guest for situations such as single
stepping of EL0 and EL1 code by EL2.

We have to track the target debug exception level in the TB
flags, because it is dependent on CPU state like HCR_EL2.TGE
and MDCR_EL2.TDE. (That we were previously calling the
arm_debug_target_el() function to determine dc->ss_same_el
is itself a bug, though one that would only have manifested
as incorrect syndrome information.) Since we are out of TB
flag bits unless we want to expand into the cs_base field,
we share some bits with the M-profile only HANDLER and
STACKCHECK bits, since only A-profile has this singlestep.

Fixes: https://bugs.launchpad.net/qemu/+bug/1838913
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190805130952.4415-3-peter.maydell@linaro.org
2019-08-16 14:02:49 +01:00
Peter Maydell c1d5f50f09 target/arm: Factor out 'generate singlestep exception' function
Factor out code to 'generate a singlestep exception', which is
currently repeated in four places.

To do this we need to also pull the identical copies of the
gen-exception() function out of translate-a64.c and translate.c
into translate.h.

(There is a bug in the code: we're taking the exception to the wrong
target EL.  This will be simpler to fix if there's only one place to
do it.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190805130952.4415-2-peter.maydell@linaro.org
2019-08-16 14:02:48 +01:00
Peter Maydell 5529de1e55 target/arm: Execute Thumb instructions when their condbits are 0xf
Thumb instructions in an IT block are set up to be conditionally
executed depending on a set of condition bits encoded into the IT
bits of the CPSR/XPSR.  The architecture specifies that if the
condition bits are 0b1111 this means "always execute" (like 0b1110),
not "never execute"; we were treating it as "never execute".  (See
the ConditionHolds() pseudocode in both the A-profile and M-profile
Arm ARM.)

This is a bit of an obscure corner case, because the only legal
way to get to an 0b1111 set of condbits is to do an exception
return which sets the XPSR/CPSR up that way. An IT instruction
which encodes a condition sequence that would include an 0b1111 is
UNPREDICTABLE, and for v8A the CONSTRAINED UNPREDICTABLE choices
for such an IT insn are to NOP, UNDEF, or treat 0b1111 like 0b1110.
Add a comment noting that we take the latter option.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190617175317.27557-7-peter.maydell@linaro.org
2019-07-04 17:25:30 +01:00