Commit Graph

594 Commits

Author SHA1 Message Date
Peter Maydell 84848481c3 target/arm: Avoid goto_tb if we're trying to exit to the main loop
Currently gen_jmp_tb() assumes that if it is called then the jump it
is handling is the only reason that we might be trying to end the TB,
so it will use goto_tb if it can.  This is usually the case: mostly
"we did something that means we must end the TB" happens on a
non-branch instruction.  However, there are cases where we decide
early in handling an instruction that we need to end the TB and
return to the main loop, and then the insn is a complex one that
involves gen_jmp_tb().  For instance, for M-profile FP instructions,
in gen_preserve_fp_state() which is called from vfp_access_check() we
want to force an exit to the main loop if lazy state preservation is
active and we are in icount mode.

Make gen_jmp_tb() look at the current value of is_jmp, and only use
goto_tb if the previous is_jmp was DISAS_NEXT or DISAS_TOO_MANY.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210913095440.13462-2-peter.maydell@linaro.org
2021-09-21 16:28:27 +01:00
Ilya Leoshkevich 4e116893c6 accel/tcg: Add DisasContextBase argument to translator_ld*
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
[rth: Split out of a larger patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-09-14 12:00:20 -07:00
Peter Maydell 520d1621de target/arm: Take an exception if PSTATE.IL is set
In v8A, the PSTATE.IL bit is set for various kinds of illegal
exception return or mode-change attempts.  We already set PSTATE.IL
(or its AArch32 equivalent CPSR.IL) in all those cases, but we
weren't implementing the part of the behaviour where attempting to
execute an instruction with PSTATE.IL takes an immediate exception
with an appropriate syndrome value.

Add a new TB flags bit tracking PSTATE.IL/CPSR.IL, and generate code
to take an exception instead of whatever the instruction would have
been.

PSTATE.IL and CPSR.IL change only on exception entry, attempted
exception exit, and various AArch32 mode changes via cpsr_write().
These places generally already rebuild the hflags, so the only place
we need an extra rebuild_hflags call is in the illegal-return
codepath of the AArch64 exception_return helper.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210821195958.41312-2-richard.henderson@linaro.org
Message-Id: <20210817162118.24319-1-peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[rth: Added missing returns; set IL bit in syndrome]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-09-13 21:01:08 +01:00
Peter Maydell 8e228c9e4b target/arm: Implement HSTR.TJDBX
In v7A, the HSTR register has a TJDBX bit which traps NS EL0/EL1
access to the JOSCR and JMCR trivial Jazelle registers, and also BXJ.
Implement these traps. In v8A this HSTR bit doesn't exist, so don't
trap for v8A CPUs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210816180305.20137-3-peter.maydell@linaro.org
2021-08-26 17:02:01 +01:00
Peter Maydell e534629296 target/arm: Implement M-profile trapping on division by zero
Unlike A-profile, for M-profile the UDIV and SDIV insns can be
configured to raise an exception on division by zero, using the CCR
DIV_0_TRP bit.

Implement support for setting this bit by making the helper functions
raise the appropriate exception.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210730151636.17254-3-peter.maydell@linaro.org
2021-08-25 10:48:50 +01:00
Peter Maydell 0f31e37c7f target/arm: Implement MVE VCTP
Implement the MVE VCTP insn, which sets the VPR.P0 predicate bits so
as to predicate any element at index Rn or greater is predicated.  As
with VPNOT, this insn itself is predicable and subject to beatwise
execution.

The calculation of the mask is the same as is used to determine
ltpmask in mve_element_mask(), but we precalculate masklen in
generated code to avoid having to have 4 helpers specialized by size.

We put the decode line in with the low-overhead-loop insns in
t32.decode because it's logically part of that collection of insn
patterns, even though it is an MVE only insn.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2021-08-25 10:48:50 +01:00
Peter Maydell 888f470f12 target/arm: Enforce that M-profile SP low 2 bits are always zero
For M-profile, unlike A-profile, the low 2 bits of SP are defined to be
RES0H, which is to say that they must be hardwired to zero so that
guest attempts to write non-zero values to them are ignored.

Implement this behaviour by masking out the low bits:
 * for writes to r13 by the gdbstub
 * for writes to any of the various flavours of SP via MSR
 * for writes to r13 via store_reg() in generated code

Note that all the direct uses of cpu_R[] in translate.c are in places
where the register is definitely not r13 (usually because that has
been checked for as an UNDEFINED or UNPREDICTABLE case and handled as
UNDEF).

All the other writes to regs[13] in C code are either:
 * A-profile only code
 * writes of values we can guarantee to be aligned, such as
   - writes of previous-SP-value plus or minus a 4-aligned constant
   - writes of the value in an SP limit register (which we already
     enforce to be aligned)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210723162146.5167-2-peter.maydell@linaro.org
2021-07-27 10:57:39 +01:00
Richard Henderson b5cf742841 accel/tcg: Remove TranslatorOps.breakpoint_check
The hook is now unused, with breakpoints checked outside translation.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-21 07:47:05 -10:00
Richard Henderson 97f11c8169 target/arm: Use translator_use_goto_tb for aarch32
Just use translator_use_goto_tb directly at the one call site,
rather than maintaining a local wrapper.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:42:28 -07:00
Richard Henderson 73fce314db target/arm: Use DISAS_TOO_MANY for ISB and SB
Using gen_goto_tb directly misses the single-step check.
Let the branch or debug exception be emitted by arm_tr_tb_stop.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:41:53 -07:00
Philippe Mathieu-Daudé 1797b08d24 tcg: Avoid including 'trace-tcg.h' in target translate.c
The root trace-events only declares a single TCG event:

  $ git grep -w tcg trace-events
  trace-events:115:# tcg/tcg-op.c
  trace-events:137:vcpu tcg guest_mem_before(TCGv vaddr, uint16_t info) "info=%d", "vaddr=0x%016"PRIx64" info=%d"

and only a tcg/tcg-op.c uses it:

  $ git grep -l trace_guest_mem_before_tcg
  tcg/tcg-op.c

therefore it is pointless to include "trace-tcg.h" in each target
(because it is not used). Remove it.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210629050935.2570721-1-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:38:33 -07:00
Peter Maydell 04ea4d3cfd target/arm: Implement MVE shifts by register
Implement the MVE shifts by register, which perform
shifts on a single general-purpose register.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-19-peter.maydell@linaro.org
2021-07-02 11:48:38 +01:00
Peter Maydell 46321d47a9 target/arm: Implement MVE shifts by immediate
Implement the MVE shifts by immediate, which perform shifts
on a single general-purpose register.

These patterns overlap with the long-shift-by-immediates,
so we have to rearrange the grouping a little here.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-18-peter.maydell@linaro.org
2021-07-02 11:48:37 +01:00
Peter Maydell 0aa4b4c358 target/arm: Implement MVE long shifts by register
Implement the MVE long shifts by register, which perform shifts on a
pair of general-purpose registers treated as a 64-bit quantity, with
the shift count in another general-purpose register, which might be
either positive or negative.

Like the long-shifts-by-immediate, these encodings sit in the space
that was previously the UNPREDICTABLE MOVS/ORRS with Rm==13,15.
Because LSLL_rr and ASRL_rr overlap with both MOV_rxri/ORR_rrri and
also with CSEL (as one of the previously-UNPREDICTABLE Rm==13 cases),
we have to move the CSEL pattern into the same decodetree group.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-17-peter.maydell@linaro.org
2021-07-02 11:48:37 +01:00
Peter Maydell f4ae6c8cbd target/arm: Implement MVE long shifts by immediate
The MVE extension to v8.1M includes some new shift instructions which
sit entirely within the non-coprocessor part of the encoding space
and which operate only on general-purpose registers.  They take up
the space which was previously UNPREDICTABLE MOVS and ORRS encodings
with Rm == 13 or 15.

Implement the long shifts by immediate, which perform shifts on a
pair of general-purpose registers treated as a 64-bit quantity, with
an immediate shift count between 1 and 32.

Awkwardly, because the MOVS and ORRS trans functions do not UNDEF for
the Rm==13,15 case, we need to explicitly emit code to UNDEF for the
cases where v8.1M now requires that.  (Trying to change MOVS and ORRS
is too difficult, because the functions that generate the code are
shared between a dozen different kinds of arithmetic or logical
instruction for all A32, T16 and T32 encodings, and for some insns
and some encodings Rm==13,15 are valid.)

We make the helper functions we need for UQSHLL and SQSHLL take
a 32-bit value which the helper casts to int8_t because we'll need
these helpers also for the shift-by-register insns, where the shift
count might be < 0 or > 32.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-16-peter.maydell@linaro.org
2021-07-02 11:48:37 +01:00
Peter Maydell 2c0286dba4 target/arm: Use asimd_imm_const for A64 decode
The A64 AdvSIMD modified-immediate grouping uses almost the same
constant encoding that A32 Neon does; reuse asimd_imm_const() (to
which we add the AArch64-specific case for cmode 15 op 1) instead of
reimplementing it all.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-5-peter.maydell@linaro.org
2021-07-02 11:48:36 +01:00
Peter Maydell dfd66bc0f3 target/arm: Make asimd_imm_const() public
The function asimd_imm_const() in translate-neon.c is an
implementation of the pseudocode AdvSIMDExpandImm(), which we will
also want for MVE.  Move the implementation to translate.c, with a
prototype in translate.h.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-4-peter.maydell@linaro.org
2021-07-02 11:48:36 +01:00
Richard Henderson ebdd503d45 target/arm: Improve REVSH
The new bswap flags can implement the semantics exactly.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
Richard Henderson 2b836c2ac1 tcg: Add flags argument to tcg_gen_bswap16_*, tcg_gen_bswap32_i64
Implement the new semantics in the fallback expansion.
Change all callers to supply the flags that keep the
semantics unchanged locally.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
Peter Maydell 6390eed45c target/arm: Add framework for MVE decode
Add the framework for decoding MVE insns, with the necessary new
files and the meson.build rules, but no actual content yet.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-11-peter.maydell@linaro.org
2021-06-16 14:33:52 +01:00
Peter Maydell a454ea1e6d target/arm: Implement MVE LETP insn
Implement the MVE LETP insn.  This is like the existing LE loop-end
insn, but it must perform an FPU-enabled check, and on loop-exit it
resets LTPSIZE to 4.

To accommodate the requirement to do something on loop-exit, we drop
the use of condlabel and instead manage both the TB exits manually,
in the same way we already do in trans_WLS().

The other MVE-specific change to the LE insn is that we must raise an
INVSTATE UsageFault insn if LTPSIZE is not 4.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-10-peter.maydell@linaro.org
2021-06-16 14:33:52 +01:00
Peter Maydell 40a36f003c target/arm: Implement MVE DLSTP
Implement the MVE DLSTP insn; this is like the existing DLS
insn, except that it must do an FPU access check and it
sets LTPSIZE to the value specified in the insn.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-9-peter.maydell@linaro.org
2021-06-16 14:33:52 +01:00
Peter Maydell 6822abfdf8 target/arm: Implement MVE WLSTP insn
Implement the MVE WLSTP insn; this is like the existing WLS insn,
except that it specifies a size value which is used to set
FPSCR.LTPSIZE.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-8-peter.maydell@linaro.org
2021-06-16 14:33:52 +01:00
Peter Maydell 76c32d721d target/arm: Implement MVE LCTP
Implement the MVE LCTP instruction.

We put its decode and implementation with the other
low-overhead-branch insns because although it is only present if MVE
is implemented it is logically in the same group as the other LOB
insns.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-7-peter.maydell@linaro.org
2021-06-16 14:33:52 +01:00
Peter Maydell 5138bd0143 target/arm: Add handling for PSR.ECI/ICI
On A-profile, PSR bits [15:10][26:25] are always the IT state bits.
On M-profile, some of the reserved encodings of the IT state are used
to instead indicate partial progress through instructions that were
interrupted partway through by an exception and can be resumed.

These resumable instructions fall into two categories:

(1) load/store multiple instructions, where these bits are called
"ICI" and specify the register in the ldm/stm list where execution
should resume.  (Specifically: LDM, STM, VLDM, VSTM, VLLDM, VLSTM,
CLRM, VSCCLRM.)

(2) MVE instructions subject to beatwise execution, where these bits
are called "ECI" and specify which beats in this and possibly also
the following MVE insn have been executed.

There are also a few insns (LE, LETP, and BKPT) which do not use the
ICI/ECI bits but must leave them alone.

Otherwise, we should raise an INVSTATE UsageFault for any attempt to
execute an insn with non-zero ICI/ECI bits.

So far we have been able to ignore ECI/ICI, because the architecture
allows the IMPDEF choice of "always restart load/store multiple from
the beginning regardless of ICI state", so the only thing we have
been missing is that we don't raise the INVSTATE fault for bad guest
code.  However, MVE requires that we honour ECI bits and do not
rexecute beats of an insn that have already been executed.

Add the support in the decoder for handling ECI/ICI:
 * identify the ECI/ICI case in the CONDEXEC TB flags
 * when a load/store multiple insn succeeds, it updates the ECI/ICI
   state (both in DisasContext and in the CPU state), and sets a flag
   to say that the ECI/ICI state was handled
 * if we find that the insn we just decoded did not handle the
   ECI/ICI state, we delete all the code that we just generated for
   it and instead emit the code to raise the INVFAULT.  This allows
   us to avoid having to update every non-MVE non-LDM/STM insn to
   make it check for "is ECI/ICI set?".

We continue with our existing IMPDEF choice of not caring about the
ICI state for the load/store multiples and simply restarting them
from the beginning.  Because we don't allow interrupts in the middle
of an insn, the only way we would see this state is if the guest set
ICI manually on return from an exception handler, so it's a corner
case which doesn't merit optimisation.

ICI update for LDM/STM is simple -- it always zeroes the state.  ECI
update for MVE beatwise insns will be a little more complex, since
the ECI state may include information for the following insn.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-5-peter.maydell@linaro.org
2021-06-16 14:33:52 +01:00
Ilya Leoshkevich 48a130923c target/arm: Make sure that commpage's tb->size != 0
tb_gen_code() assumes that tb->size must never be zero, otherwise it
may produce spurious exceptions. For ARM this may happen when creating
a translation block for the commpage.

Fix by pretending that commpage translation blocks have at least one
instruction.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210416154939.32404-3-iii@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2021-05-20 14:19:30 +02:00
Peter Maydell 4800b852b8 target/arm: Make translate-neon.c.inc its own compilation unit
Switch translate-neon.c.inc from being #included into translate.c
to being its own compilation unit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-14-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell b5c8a457fa target/arm: Make functions used by translate-neon global
Make the remaining functions needed by the translate-neon code
global.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-13-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 9194a9cbc7 target/arm: Move NeonGenThreeOpEnvFn typedef to translate.h
Move the NeonGenThreeOpEnvFn typedef to translate.h together
with the other similar typedefs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210430132740.10391-12-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 8e30454fed target/arm: Delete unused typedef
The VFPGenFixPointFn typedef is unused; delete it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210430132740.10391-11-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell eb554d612d target/arm: Move vfp_reg_ptr() to translate-neon.c.inc
The function vfp_reg_ptr() is used only in translate-neon.c.inc;
move it there.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-10-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 45fbd5a967 target/arm: Make translate-vfp.c.inc its own compilation unit
Switch translate-vfp.c.inc from being #included into translate.c
to being its own compilation unit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-9-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 4a800a739d target/arm: Make functions used by translate-vfp global
Make the remaining functions which are needed by translate-vfp.c.inc
global.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-8-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 06085d6a10 target/arm: Move vfp_{load, store}_reg{32, 64} to translate-vfp.c.inc
The functions vfp_load_reg32(), vfp_load_reg64(), vfp_store_reg32()
and vfp_store_reg64() are used only in translate-vfp.c.inc. Move
them to that file.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-7-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 73d2f5d2bb target/arm: Move gen_aa32 functions to translate-a32.h
Move the various gen_aa32* functions and macros out of translate.c
and into translate-a32.h.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-6-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 9a5071abbc target/arm: Split m-nocp trans functions into their own file
Currently the trans functions for m-nocp.decode all live in
translate-vfp.inc.c; move them out into their own translation unit,
translate-m-nocp.c.

The trans_* functions here are pure code motion with no changes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-5-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell 5ce389f2e7 target/arm: Make functions used by m-nocp global
We want to split out the .c.inc files which are currently included
into translate.c so they are separate compilation units.  To do this
we need to make some functions which are currently file-local to
translate.c have global scope; create a translate-a32.h paralleling
the existing translate-a64.h as a place for these declarations to
live, so that code moved into the new compilation units can call
them.

The functions made global here are those required by the
m-nocp.decode functions, except that I have converted the whole
family of {read,write}_neon_element* and also both the load_cpu and
store_cpu functions for consistency, even though m-nocp only wants a
few functions from each.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-4-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell d9318a5f9c target/arm: Share unallocated_encoding() and gen_exception_insn()
The unallocated_encoding() function is the same in both
translate-a64.c and translate.c; make the translate.c function global
and drop the translate-a64.c version.  To do this we need to also
share gen_exception_insn(), which currently exists in two slightly
different versions for A32 and A64: merge those into a single
function that can work for both.

This will be useful for splitting up translate.c, which will require
unallocated_encoding() to no longer be file-local.  It's also
hopefully less confusing to have only one version of the function
rather than two.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-3-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Peter Maydell b5aa664679 target/arm: Move constant expanders to translate.h
Some of the constant expanders defined in translate.c are generically
useful and will be used by the separate C files for VFP and Neon once
they are created; move the expander definitions to translate.h.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210430132740.10391-2-peter.maydell@linaro.org
2021-05-10 13:24:09 +01:00
Richard Henderson a8502b37f6 target/arm: Enforce alignment for VLDn (all lanes)
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-23-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:51 +01:00
Richard Henderson 2fd0800c68 target/arm: Enforce alignment for SRS
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:51 +01:00
Richard Henderson c0c7f66087 target/arm: Enforce alignment for RFE
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-19-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:51 +01:00
Richard Henderson 2e1f39e29b target/arm: Enforce alignment for LDM/STM
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-18-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:51 +01:00
Richard Henderson 824efdf525 target/arm: Enforce alignment for LDA/LDAH/STL/STLH
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 4d753eb5fb target/arm: Enforce word alignment for LDRD/STRD
Buglink: https://bugs.launchpad.net/qemu/+bug/1905356
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-16-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson abe66294e1 target/arm: Adjust gen_aa32_{ld, st}_i64 for align+endianness
Adjust the interface to match what has been done to the
TCGv_i32 load/store functions.

This is less obvious, because at present the only user of
these functions, trans_VLDST_multiple, also wants to manipulate
the endianness to speed up loading multiple bytes.  Thus we
retain an "internal" interface which is identical to the
current gen_aa32_{ld,st}_i64 interface.

The "new" interface will gain users as we remove the legacy
interfaces, gen_aa32_ld64 and gen_aa32_st64.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 9565ac4cc7 target/arm: Fix SCTLR_B test for TCGv_i64 load/store
Just because operating on a TCGv_i64 temporary does not
mean that we're performing a 64-bit operation.  Restrict
the frobbing to actual 64-bit operations.

This bug is not currently visible because all current
users of these two functions always pass MO_64.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 37bf7a055f target/arm: Merge gen_aa32_frob64 into gen_aa32_ld_i64
This is the only caller.  Adjust some commentary to talk
about SCTLR_B instead of the vanishing function.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 9d486b40e8 target/arm: Adjust gen_aa32_{ld, st}_i32 for align+endianness
Create a finalize_memop function that computes alignment and
endianness and returns the final MemOp for the operation.

Split out gen_aa32_{ld,st}_internal_i32 which bypasses any special
handling of endianness or alignment.  Adjust gen_aa32_{ld,st}_i32
so that s->be_data is not added by the callers.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 4479ec30c9 target/arm: Add ALIGN_MEM to TBFLAG_ANY
Use this to signal when memory access alignment is required.
This value comes from the CCR register for M-profile, and
from the SCTLR register for A-profile.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 3902bfc6f0 target/arm: Introduce CPUARMTBFlags
In preparation for splitting tb->flags across multiple
fields, introduce a structure to hold the value(s).
So far this only migrates the one uint32_t and fixes
all of the places that require adjustment to match.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson a729a46b05 target/arm: Add wrapper macros for accessing tbflags
We're about to split tbflags into two parts.  These macros
will ensure that the correct part is used with the correct
set of bits.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson ae6eb1e9b3 target/arm: Rename TBFLAG_ANY, PSTATE_SS
We're about to rearrange the macro expansion surrounding tbflags,
and this field name will be expanded using the bit definition of
the same name, resulting in a token pasting error.

So PSTATE_SS -> PSTATE__SS in the uses, and document it.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:50 +01:00
Richard Henderson 6a01eab7d8 target/arm: Rename TBFLAG_A32, SCTLR_B
We're about to rearrange the macro expansion surrounding tbflags,
and this field name will be expanded using the bit definition of
the same name, resulting in a token pasting error.

So SCTLR_B -> SCTLR__B in the 3 uses, and document it.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-30 11:16:49 +01:00
Peter Maydell 8196fe9d83 target/arm: Make Thumb store insns UNDEF for Rn==1111
The Arm ARM specifies that for Thumb encodings of the various plain
store insns, if the Rn field is 1111 then we must UNDEF.  This is
different from the Arm encodings, where this case is either
UNPREDICTABLE or has well-defined behaviour.  The exclusive stores,
store-release and STRD do not have this UNDEF case for any encoding.

Enforce the UNDEF for this case in the Thumb plain store insns.

Fixes: https://bugs.launchpad.net/qemu/+bug/1922887
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210408162402.5822-1-peter.maydell@linaro.org
2021-04-30 11:16:49 +01:00
Alex Bennée c57b27ea89 target/arm: drop CF_LAST_IO/dc->condjump check
This is a left over erroneous check from the days front-ends handled
io start/end themselves. Regardless just because IO could be performed
on the last instruction doesn't obligate the front end to do so.

This fixes an abort faced by the aspeed execute-in-place support which
will necessarily trigger this state (even before the one-shot
CF_LAST_IO fix). The test still seems to hang once it attempts to boot
the Linux kernel but I suspect this is an unrelated issue with icount
and the timer handling code.

The original intention of the cpu_abort (added in commit 2e70f6efa8
when the icount stuff was first added) seems to have been to act as
an assert() to catch an unhandled corner case where the generated code
would be something like:
    conditional branch to condlabel if its cc failed
    implementation of the insn (a conditional branch or trap)
    code emitted by gen_io_end()
 condlabel:
    gen_goto_tb or equivalent thing to go to next insn

At runtime the cc-failed case would skip over the code emitted by
gen_io_end(), leaving the can_do_io flag incorrectly set.

In commit ba3e792669 we switched to an implementation which
always clears can_do_io at the start of the following TB instead
of trying to clear it at the end of a TB that did IO. So the corner
case that this cpu_abort() was trying to flag is no longer possible,
because the gen_io_end() call has been deleted. We can therefore
safely remove the no-longer-valid assertion.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210416170207.12504-1-alex.bennee@linaro.org
Cc: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-17 18:48:05 +01:00
Philippe Mathieu-Daudé 6b5fe13786 semihosting: Move include/hw/semihosting/ -> include/semihosting/
We want to move the semihosting code out of hw/ in the next patch.

This patch contains the mechanical steps, created using:

  $ git mv include/hw/semihosting/ include/
  $ sed -i s,hw/semihosting,semihosting, $(git grep -l hw/semihosting)

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210226131356.3964782-2-f4bug@amsat.org>
Message-Id: <20210305135451.15427-2-alex.bennee@linaro.org>
2021-03-10 15:34:12 +00:00
Rémi Denis-Courmont 926c1b9789 target/arm: Implement SCR_EL2.EEL2
This adds handling for the SCR_EL3.EEL2 bit.

Signed-off-by: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>
Message-id: 20210112104511.36576-17-remi.denis.courmont@huawei.com
[PMM: Applied fixes for review issues noted by RTH:
 - check for FEATURE_AARCH64 before checking sel2 isar feature
 - correct the commit message subject line]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-01-19 14:38:52 +00:00
Rémi Denis-Courmont 6b340aeb48 target/arm: revector to run-time pick target EL
On ARMv8-A, accesses by 32-bit secure EL1 to monitor registers trap to
the upper (64-bit) EL. With Secure EL2 support, we can no longer assume
that that is always EL3, so make room for the value to be computed at
run-time.

Signed-off-by: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210112104511.36576-16-remi.denis.courmont@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-01-19 14:38:52 +00:00
Peter Maydell e4d51ac692 target/arm: Don't decode insns in the XScale/iWMMXt space as cp insns
In commit cd8be50e58 we converted the A32 coprocessor
insns to decodetree. This accidentally broke XScale/iWMMXt insns,
because it moved the handling of "cp insns which are handled
by looking up the cp register in the hashtable" from after the
call to the legacy disas_xscale_insn() decode to before it,
with the result that all XScale/iWMMXt insns now UNDEF.

Update valid_cp() so that it knows that on XScale cp 0 and 1
are not standard coprocessor instructions; this will cause
the decodetree trans_ functions to ignore them, so that
execution will correctly get through to the legacy decode again.

Cc: qemu-stable@nongnu.org
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 20210108195157.32067-1-peter.maydell@linaro.org
2021-01-12 21:19:02 +00:00
Peter Maydell f7ed0c9433 target/arm: Move general-use constant expanders up in translate.c
The constant-expander functions like negate, plus_2, etc, are
generally useful; move them up in translate.c so we can use them in
the VFP/Neon decoders as well as in the A32/T32/T16 decoders.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-9-peter.maydell@linaro.org
2020-12-10 11:44:55 +00:00
Peter Maydell 6e21a013fb target/arm: Implement CLRM instruction
In v8.1M the new CLRM instruction allows zeroing an arbitrary set of
the general-purpose registers and APSR.  Implement this.

The encoding is a subset of the LDMIA T2 encoding, using what would
be Rn=0b1111 (which UNDEFs for LDMIA).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-6-peter.maydell@linaro.org
2020-12-10 11:44:55 +00:00
Peter Maydell 83ff3d6add target/arm: Implement VSCCLRM insn
Implement the v8.1M VSCCLRM insn, which zeros floating point
registers if there is an active floating point context.
This requires support in write_neon_element32() for the MO_32
element size, so add it.

Because we want to use arm_gen_condlabel(), we need to move
the definition of that function up in translate.c so it is
before the #include of translate-vfp.c.inc.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-5-peter.maydell@linaro.org
2020-12-10 11:44:55 +00:00
Chetan Pant 50f57e09fd arm tcg cpus: Fix Lesser GPL version number
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201023122913.19561-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-11-15 16:42:14 +01:00
Xinhao Zhang 7f350a87e3 target/arm: add space before the open parenthesis '('
Fix code style. Space required before the open parenthesis '('.

Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com>
Signed-off-by: Kai Deng <dengkai1@huawei.com>
Message-id: 20201103114529.638233-3-zhangxinhao1@huawei.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-10 11:03:48 +00:00
Richard Henderson 8aab18a2c5 target/arm: Improve do_prewiden_3d
We can use proper widening loads to extend 32-bit inputs,
and skip the "widenfn" step.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-12-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:15 +00:00
Richard Henderson b38b96ca90 target/arm: Rename neon_load_reg64 to vfp_load_reg64
The only uses of this function are for loading VFP
double-precision values, and nothing to do with NEON.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-10-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:14 +00:00
Richard Henderson 0aa8e700a5 target/arm: Add read/write_neon_element64
Replace all uses of neon_load/store_reg64 within translate-neon.c.inc.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-9-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:14 +00:00
Richard Henderson 21c1c0e50b target/arm: Rename neon_load_reg32 to vfp_load_reg32
The only uses of this function are for loading VFP
single-precision values, and nothing to do with NEON.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-8-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:14 +00:00
Richard Henderson 4d5fa5a80a target/arm: Expand read/write_neon_element32 to all MemOp
We can then use this to improve VMOV (scalar to gp) and
VMOV (gp to scalar) so that we simply perform the memory
operation that we wanted, rather than inserting or
extracting from a 32-bit quantity.

These were the last uses of neon_load/store_reg, so remove them.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-7-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:14 +00:00
Richard Henderson a712266f5d target/arm: Add read/write_neon_element32
Model these off the aa64 read/write_vec_element functions.
Use it within translate-neon.c.inc.  The new functions do
not allocate or free temps, so this rearranges the calling
code a bit.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:13 +00:00
Richard Henderson d8719785fd target/arm: Use neon_element_offset in vfp_reg_offset
This seems a bit more readable than using offsetof CPU_DoubleU.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:13 +00:00
Richard Henderson 0f2cdc8227 target/arm: Use neon_element_offset in neon_load/store_reg
These are the only users of neon_reg_offset, so remove that.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-4-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:13 +00:00
Richard Henderson 7ec85c0283 target/arm: Move neon_element_offset to translate.c
This will shortly have users outside of translate-neon.c.inc.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:13 +00:00
Richard Henderson 015ee81a4c target/arm: Introduce neon_full_reg_offset
This function makes it clear that we're talking about the whole
register, and not the 32-bit piece at index 0.  This fixes a bug
when running on a big-endian host.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-11-02 16:52:12 +00:00
Peter Maydell b722636972 target/arm: Implement v8.1M low-overhead-loop instructions
v8.1M's "low-overhead-loop" extension has three instructions
for looping:
 * DLS (start of a do-loop)
 * WLS (start of a while-loop)
 * LE (end of a loop)

The loop-start instructions are both simple operations to start a
loop whose iteration count (if any) is in LR.  The loop-end
instruction handles "decrement iteration count and jump back to loop
start"; it also caches the information about the branch back to the
start of the loop to improve performance of the branch on subsequent
iterations.

As with the branch-future instructions, the architecture permits an
implementation to discard the LO_BRANCH_INFO cache at any time, and
QEMU takes the IMPDEF option to never set it in the first place
(equivalent to discarding it immediately), because for us a "real"
implementation would be unnecessary complexity.

(This implementation only provides the simple looping constructs; the
vector extension MVE (Helium) adds some extra variants to handle
looping across vectors.  We'll add those later when we implement
MVE.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201019151301.2046-8-peter.maydell@linaro.org
2020-10-20 16:12:01 +01:00
Peter Maydell 05903f036e target/arm: Implement v8.1M branch-future insns (as NOPs)
v8.1M implements a new 'branch future' feature, which is a
set of instructions that request the CPU to perform a branch
"in the future", when it reaches a particular execution address.
In hardware, the expected implementation is that the information
about the branch location and destination is cached and then
acted upon when execution reaches the specified address.
However the architecture permits an implementation to discard
this cached information at any point, and so guest code must
always include a normal branch insn at the branch point as
a fallback. In particular, an implementation is specifically
permitted to treat all BF insns as NOPs (which is equivalent
to discarding the cached information immediately).

For QEMU, implementing this caching of branch information
would be complicated and would not improve the speed of
execution at all, so we make the IMPDEF choice to implement
all BF insns as NOPs.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20201019151301.2046-7-peter.maydell@linaro.org
2020-10-20 16:12:01 +01:00
Peter Maydell 920f04fa3e target/arm: Don't allow BLX imm for M-profile
The BLX immediate insn in the Thumb encoding always performs
a switch from Thumb to Arm state. This would be totally useless
in M-profile which has no Arm decoder, and so the instruction
does not exist at all there. Make the encoding UNDEF for M-profile.

(This part of the encoding space is used for the branch-future
and low-overhead-loop insns in v8.1M.)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20201019151301.2046-6-peter.maydell@linaro.org
2020-10-20 16:12:01 +01:00
Peter Maydell cc73bbded0 target/arm: Implement v8.1M conditional-select insns
v8.1M brings four new insns to M-profile:
 * CSEL  : Rd = cond ? Rn : Rm
 * CSINC : Rd = cond ? Rn : Rm+1
 * CSINV : Rd = cond ? Rn : ~Rm
 * CSNEG : Rd = cond ? Rn : -Rm

Implement these.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20201019151301.2046-4-peter.maydell@linaro.org
2020-10-20 16:12:01 +01:00
Peter Maydell 5288145d71 target/arm: Fix SMLAD incorrect setting of Q bit
The SMLAD instruction is supposed to:
 * signed multiply Rn[15:0] * Rm[15:0]
 * signed multiply Rn[31:16] * Rm[31:16]
 * perform a signed addition of the products and Ra
 * set Rd to the low 32 bits of the theoretical
   infinite-precision result
 * set the Q flag if the sign-extension of Rd
   would differ from the infinite-precision result
   (ie on overflow)

Our current implementation doesn't quite do this, though: it performs
an addition of the products setting Q on overflow, and then it adds
Ra, again possibly setting Q.  This sometimes incorrectly sets Q when
the architecturally mandated only-check-for-overflow-once algorithm
does not. For instance:
 r1 = 0x80008000; r2 = 0x80008000; r3 = 0xffffffff
 smlad r0, r1, r2, r3
This is (-32768 * -32768) + (-32768 * -32768) - 1

The products are both 0x4000_0000, so when added together as 32-bit
signed numbers they overflow (and QEMU sets Q), but because the
addition of Ra == -1 brings the total back down to 0x7fff_ffff
there is no overflow for the complete operation and setting Q is
incorrect.

Fix this edge case by resorting to 64-bit arithmetic for the
case where we need to add three values together.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201009144712.11187-1-peter.maydell@linaro.org
2020-10-20 16:12:00 +01:00
Peter Maydell a84d1d1316 target/arm: Make A32/T32 use new fpstatus_ptr() API
Make A32/T32 code use the new fpstatus_ptr() API:
 get_fpstatus_ptr(0) -> fpstatus_ptr(FPST_FPCR)
 get_fpstatus_ptr(1) -> fpstatus_ptr(FPST_STD)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200806104453.30393-3-peter.maydell@linaro.org
2020-08-24 10:15:11 +01:00
Peter Maydell 8b4c9a50dc target/arm/translate.c: Delete/amend incorrect comments
In arm_tr_init_disas_context() we have a FIXME comment that suggests
"cpu_M0 can probably be the same as cpu_V0".  This isn't in fact
possible: cpu_V0 is used as a temporary inside gen_iwmmxt_shift(),
and that function is called in various places where cpu_M0 contains a
live value (i.e.  between gen_op_iwmmxt_movq_M0_wRn() and
gen_op_iwmmxt_movq_wRn_M0() calls).  Remove the comment.

We also have a comment on the declarations of cpu_V0/V1/M0 which
claims they're "for efficiency".  This isn't true with modern TCG, so
replace this comment with one which notes that they're only used with
the iwmmxt decode.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803132815.3861-1-peter.maydell@linaro.org
2020-08-24 10:15:11 +01:00
Peter Maydell e60527c5d5 target/arm: Delete unused VFP_DREG macros
As part of the Neon decodetree conversion we removed all
the uses of the VFP_DREG macros, but forgot to remove the
macro definitions. Do so now.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200803124848.18295-1-peter.maydell@linaro.org
2020-08-24 10:15:11 +01:00
Peter Maydell ce51c7f522 target/arm: Remove ARCH macro
The ARCH() macro was used a lot in the legacy decoder, but
there are now just two uses of it left. Since a macro which
expands out to a goto is liable to be confusing when reading
code, replace the last two uses with a simple open-coded
qeuivalent.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-8-peter.maydell@linaro.org
2020-08-24 10:15:11 +01:00
Peter Maydell 4c498dcfd8 target/arm: Convert T32 coprocessor insns to decodetree
Convert the T32 coprocessor instructions to decodetree.
As with the A32 conversion, this corrects an underdecoding
where we did not check that MRRC/MCRR [24:21] were 0b0010
and so treated some kinds of LDC/STC and MRRC/MCRR rather
than UNDEFing them.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-7-peter.maydell@linaro.org
2020-08-24 10:15:08 +01:00
Peter Maydell a3494d4671 target/arm: Do M-profile NOCP checks early and via decodetree
For M-profile CPUs, the architecture specifies that the NOCP
exception when a coprocessor is not present or disabled should cover
the entire wide range of coprocessor-space encodings, and should take
precedence over UNDEF exceptions.  (This is the opposite of
A-profile, where checking for a disabled FPU has to happen last.)

Implement this with decodetree patterns that cover the specified
ranges of the encoding space.  There are a few instructions (VLLDM,
VLSTM, and in v8.1 also VSCCLRM) which are in copro-space but must
not be NOCP'd: these must be handled also in the new m-nocp.decode so
they take precedence.

This is a minor behaviour change: for unallocated insn patterns in
the VFP area (cp=10,11) we will now NOCP rather than UNDEF when the
FPU is disabled.

As well as giving us the correct architectural behaviour for v8.1M
and the recommended behaviour for v8.0M, this refactoring also
removes the old NOCP handling from the remains of the 'legacy
decoder' in disas_thumb2_insn(), paving the way for cleaning that up.

Since we don't currently have a v8.1M feature bit or any v8.1M CPUs,
the minor changes to this logic that we'll need for v8.1M are marked
up with TODO comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-6-peter.maydell@linaro.org
2020-08-24 10:05:12 +01:00
Peter Maydell 8198c071bc target/arm: Tidy up disas_arm_insn()
The only thing left in the "legacy decoder" is the handling
of disas_xscale_insn(), and we can simplify the code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-5-peter.maydell@linaro.org
2020-08-24 10:02:07 +01:00
Peter Maydell cd8be50e58 target/arm: Convert A32 coprocessor insns to decodetree
Convert the A32 coprocessor instructions to decodetree.

Note that this corrects an underdecoding: for the 64-bit access case
(MRRC/MCRR) we did not check that bits [24:21] were 0b0010, so we
would incorrectly treat LDC/STC as MRRC/MCRR rather than UNDEFing
them.

The decodetree versions of these insns assume the coprocessor
is in the range 0..7 or 14..15. This is architecturally sensible
(as per the comments) and OK in practice for QEMU because the only
uses of the ARMCPRegInfo infrastructure we have that aren't
for coprocessors 14 or 15 are the pxa2xx use of coprocessor 6.
We add an assertion to the define_one_arm_cp_reg_with_opaque()
function to catch any accidental future attempts to use it to
define coprocessor registers for invalid coprocessors.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-4-peter.maydell@linaro.org
2020-08-24 10:02:07 +01:00
Peter Maydell 19c23a9baa target/arm: Separate decode from handling of coproc insns
As a prelude to making coproc insns use decodetree, split out the
part of disas_coproc_insn() which does instruction decoding from the
part which does the actual work, and make do_coproc_insn() handle the
UNDEF-on-bad-permissions and similar cases itself rather than
returning 1 to eventually percolate up to a callsite that calls
unallocated_encoding() for it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-3-peter.maydell@linaro.org
2020-08-24 10:02:06 +01:00
Peter Maydell 7b4f933db8 target/arm: Pull handling of XScale insns out of disas_coproc_insn()
At the moment we check for XScale/iwMMXt insns inside
disas_coproc_insn(): for CPUs with ARM_FEATURE_XSCALE all copro insns
with cp 0 or 1 are handled specially.  This works, but is an odd
place for this check, because disas_coproc_insn() is called from both
the Arm and Thumb decoders but the XScale case never applies for
Thumb (all the XScale CPUs were ARMv5, which has only Thumb1, not
Thumb2 with the 32-bit coprocessor insn encodings).  It also makes it
awkward to convert the real copro access insns to decodetree.

Move the identification of XScale out to its own function
which is only called from disas_arm_insn().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-2-peter.maydell@linaro.org
2020-08-24 10:02:06 +01:00
Paolo Bonzini 139c1837db meson: rename included C source files to .c.inc
With Makefiles that have automatically generated dependencies, you
generated includes are set as dependencies of the Makefile, so that they
are built before everything else and they are available when first
building the .c files.

Alternatively you can use a fine-grained dependency, e.g.

        target/arm/translate.o: target/arm/decode-neon-shared.inc.c

With Meson you have only one choice and it is a third option, namely
"build at the beginning of the corresponding target"; the way you
express it is to list the includes in the sources of that target.

The problem is that Meson decides if something is a source vs. a
generated include by looking at the extension: '.c', '.cc', '.m', '.C'
are sources, while everything else is considered an include---including
'.inc.c'.

Use '.c.inc' to avoid this, as it is consistent with our other convention
of using '.rst.inc' for included reStructuredText files.  The editorconfig
file is adjusted.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:18:30 -04:00
Richard Henderson 329833286d target/arm: Add DISAS_UPDATE_NOCHAIN
Add an option that writes back the PC, like DISAS_UPDATE_EXIT,
but does not exit back to the main loop.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-06-26 14:31:12 +01:00
Richard Henderson 14407ec200 target/arm: Rename DISAS_UPDATE to DISAS_UPDATE_EXIT
Emphasize that the is_jmp option exits to the main loop.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-06-26 14:31:12 +01:00
Peter Maydell 55c812b742 target/arm: Remove unnecessary gen_io_end() calls
Since commit ba3e792669 it has been unnecessary for target code
to call gen_io_end() after an IO instruction in icount mode; it is
sufficient to call gen_io_start() before it and to force the end of
the TB.

Many now-unnecessary calls to gen_io_end() were removed in commit
9e9b10c649, but some were missed or accidentally added later.
Remove unneeded calls from the arm target:

 * the call in the handling of exception-return-via-LDM is
   unnecessary, and the code is already forcing end-of-TB
 * the call in the VFP access check code is more complicated:
   we weren't ending the TB, so we need to add the code to
   force that by setting DISAS_UPDATE
 * the doc comment for ARM_CP_IO doesn't need to mention
   gen_io_end() any more

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-id: 20200619170324.12093-1-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00
Peter Maydell 6fb5787898 target/arm: Move some functions used only in translate-neon.inc.c to that file
The functions neon_element_offset(), neon_load_element(),
neon_load_element64(), neon_store_element() and
neon_store_element64() are used only in the translate-neon.inc.c
file, so move their definitions there.

Since the .inc.c file is #included in translate.c this doesn't make
much difference currently, but it's a more logical place to put the
functions and it might be helpful if we ever decide to try to make
the .inc.c files genuinely separate compilation units.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200616170844.13318-22-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00
Peter Maydell d4366190f8 target/arm: Convert Neon VTRN to decodetree
Convert the Neon VTRN insn to decodetree. This is the last insn in the
Neon data-processing group, so we can remove all the now-unused old
decoder framework.

It's possible that there's a more efficient implementation of
VTRN, but for this conversion we just copy the existing approach.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200616170844.13318-21-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00
Peter Maydell 8ab3a227a0 target/arm: Convert Neon VSWP to decodetree
Convert the Neon VSWP insn to decodetree. Since the new implementation
doesn't have to share a pass-loop with the other 2-reg-misc operations
we can implement the swap with 64-bit accesses rather than 32-bits
(which brings us into line with the pseudocode and is more efficient).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200616170844.13318-20-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00
Peter Maydell a183d5fb38 target/arm: Convert Neon 2-reg-misc VCVT insns to decodetree
Convert the VCVT instructions in the 2-reg-misc grouping to
decodetree.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200616170844.13318-19-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00
Peter Maydell 128123ea34 target/arm: Convert Neon 2-reg-misc VRINT insns to decodetree
Convert the Neon 2-reg-misc VRINT insns to decodetree.
Giving these insns their own do_vrint() function allows us
to change the rounding mode just once at the start and end
rather than doing it for every element in the vector.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200616170844.13318-18-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00
Peter Maydell baa59323e8 target/arm: Convert Neon 2-reg-misc fp-compare-with-zero insns to decodetree
Convert the fp-compare-with-zero insns in the Neon 2-reg-misc group to
decodetree.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200616170844.13318-17-peter.maydell@linaro.org
2020-06-23 11:39:47 +01:00