Commit Graph

126 Commits

Author SHA1 Message Date
Peter Maydell
34a8a07e57 target/arm: Implement the HFGITR_EL2.SVC_EL0 and SVC_EL1 traps
Implement the HFGITR_EL2.SVC_EL0 and SVC_EL1 fine-grained traps.
These trap execution of the SVC instruction from AArch32 and AArch64.
(As usual, AArch32 can only trap from EL0, as fine grained traps are
disabled with an AArch32 EL1.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-22-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-22-peter.maydell@linaro.org
2023-02-03 12:59:24 +00:00
Peter Maydell
5572f7557f target/arm: Implement the HFGITR_EL2.ERET trap
Implement the HFGITR_EL2.ERET fine-grained trap.  This traps
execution from AArch64 EL1 of ERET, ERETAA and ERETAB.  The trap is
reported with a syndrome value of 0x1a.

The trap must take precedence over a possible pointer-authentication
trap for ERETAA and ERETAB.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-21-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-21-peter.maydell@linaro.org
2023-02-03 12:59:24 +00:00
Peter Maydell
361c33f6b8 target/arm: Implement FGT trapping infrastructure
Implement the machinery for fine-grained traps on normal sysregs.
Any sysreg with a fine-grained trap will set the new field to
indicate which FGT register bit it should trap on.

FGT traps only happen when an AArch64 EL2 enables them for
an AArch64 EL1. They therefore are only relevant for AArch32
cpregs when the cpreg can be accessed from EL0. The logic
in access_check_cp_reg() will check this, so it is safe to
add a .fgt marking to an ARM_CP_STATE_BOTH ARMCPRegInfo.

The DO_BIT and DO_REV_BIT macros define enum constants FGT_##bitname
which can be used to specify the FGT bit, eg
   .fgt = FGT_AFSR0_EL1
(We assume that there is no bit name duplication across the FGT
registers, for brevity's sake.)

Subsequent commits will add the .fgt fields to the relevant register
definitions and define the FGT_nnn values for them.

Note that some of the FGT traps are for instructions that we don't
handle via the cpregs mechanisms (mostly these are instruction traps).
Those we will have to handle separately.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-10-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-10-peter.maydell@linaro.org
2023-02-03 12:59:23 +00:00
Richard Henderson
3b07a936d3 target/arm: Look up ARMCPRegInfo at runtime
Do not encode the pointer as a constant in the opcode stream.
This pointer is specific to the cpu that first generated the
translation, which runs into problems with both hot-pluggable
cpus and user-only threads, as cpus are removed. It's also a
potential correctness issue in the theoretical case of a
slightly-heterogenous system, because if CPU 0 generates a
TB and then CPU 1 executes it, CPU 1 will end up using CPU 0's
hash table, which might have a wrong set of registers in it.
(All our current systems are either completely homogenous,
M-profile, or have CPUs sufficiently different that they
wouldn't be sharing TBs anyway because the differences would
show up in the TB flags, so the correctness issue is only
theoretical, not practical.)

Perform the lookup in either helper_access_check_cp_reg,
or a new helper_lookup_cp_reg.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230106194451.1213153-3-richard.henderson@linaro.org
[PMM: added note in commit message about correctness issue]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-01-23 13:32:38 +00:00
Richard Henderson
abb80995d7 target/arm: Enable TARGET_TB_PCREL
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221020030641.2066807-10-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-10-20 11:28:29 +01:00
Richard Henderson
55086e628f target/arm: Change gen_exception_insn* to work on displacements
In preparation for TARGET_TB_PCREL, reduce reliance on absolute values.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221020030641.2066807-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-10-20 11:27:52 +01:00
Richard Henderson
c44c8b8b99 target/arm: Change gen_*set_pc_im to gen_*update_pc
In preparation for TARGET_TB_PCREL, reduce reliance on
absolute values by passing in pc difference.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221020030641.2066807-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-10-20 11:27:52 +01:00
Richard Henderson
8df8727973 target/arm: Introduce curr_insn_len
A simple helper to retrieve the length of the current insn.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221020030641.2066807-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-10-20 11:27:52 +01:00
Richard Henderson
e9ad3ef19e target/arm: Implement SME MOVA
We can reuse the SVE functions for implementing moves to/from
horizontal tile slices, but we need new ones for moves to/from
vertical tile slices.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-07-11 13:19:35 +01:00
Richard Henderson
7160c8c55a target/arm: Mark ADR as non-streaming
Mark ADR as a non-streaming instruction, which should trap
if full a64 support is not enabled in streaming mode.

Removing entries from sme-fa64.decode is an easy way to see
what remains to be done.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-07-11 13:19:35 +01:00
Richard Henderson
75fe83564a target/arm: Trap non-streaming usage when Streaming SVE is active
This new behaviour is in the ARM pseudocode function
AArch64.CheckFPAdvSIMDEnabled, which applies to AArch32
via AArch32.CheckAdvSIMDOrFPEnabled when the EL to which
the trap would be delivered is in AArch64 mode.

Given that ARMv9 drops support for AArch32 outside EL0, the trap EL
detection ought to be trivially true, but the pseudocode still contains
a number of conditions, and QEMU has not yet committed to dropping A32
support for EL[12] when v9 features are present.

Since the computation of SME_TRAP_NONSTREAMING is necessarily different
for the two modes, we might as well preserve bits within TBFLAG_ANY and
allocate separate bits within TBFLAG_A32 and TBFLAG_A64 instead.

Note that DDI0616A.a has typos for bits [22:21] of LD1RO in the table
of instructions illegal in streaming mode.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-07-11 13:19:35 +01:00
Richard Henderson
5d7953adcf target/arm: Add SVL to TB flags
We need SVL separate from VL for RDSVL et al, as well as
ZA storage loads and stores, which do not require PSTATE.SM.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220620175235.60881-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-27 11:18:17 +01:00
Richard Henderson
a3637e8882 target/arm: Add PSTATE.{SM,ZA} to TB flags
These are required to determine if various insns
are allowed to issue.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220620175235.60881-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-27 11:18:17 +01:00
Richard Henderson
6b2ca83e4c target/arm: Add SMEEXC_EL to TB flags
This is CheckSMEAccess, which is the basis for a set of
related tests for various SME cpregs and instructions.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220620175235.60881-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-27 11:18:17 +01:00
Richard Henderson
82303761c6 target/arm: Remove default_exception_el
This function is no longer used.  At the same time, remove
DisasContext.secure_routed_to_el3, as it in turn becomes unused.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:34 +01:00
Richard Henderson
cc5e672b85 target/arm: Move gen_exception to translate.c
This function is not required by any other translation file.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-16-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:33 +01:00
Richard Henderson
8480e933ed target/arm: Remove TBFLAG_ANY.DEBUG_TARGET_EL
We no longer need this value during translation,
as it is now handled within the helpers.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:33 +01:00
Richard Henderson
f0d7c2054a target/arm: Create helper_exception_swstep
Move the computation from gen_swstep_exception into a helper.

This fixes a bug when:
  - MDSCR_EL1.KDE == 1 to enable debug exceptions within EL_D itself
  - we singlestep an ERET from EL_D to some lower EL

Previously we were computing 'same el' based on the EL which
executed the ERET instruction, whereas it ought to be computed
based on the EL to which ERET returned.  This happens naturally
with the new helper, which runs after EL has been changed.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:32 +01:00
Richard Henderson
486d6c9699 target/arm: Introduce gen_exception_insn
Create a new wrapper function that passes the default
exception target to gen_exception_insn_el.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:32 +01:00
Richard Henderson
8c5d24dc7d target/arm: Rename gen_exception_insn to gen_exception_insn_el
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:32 +01:00
Richard Henderson
d3c5d50a5c target/arm: Rename helper_exception_with_syndrome
Rename to helper_exception_with_syndrome_el, to emphasize
that the target el is a parameter.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-10 14:32:31 +01:00
Richard Henderson
f45ce4c35f target/arm: Rename TBFLAG_A64 ZCR_LEN to VL
With SME, the vector length does not only come from ZCR_ELx.
Comment that this is either NVL or SVL, like the pseudocode.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220607203306.657998-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-06-08 19:38:54 +01:00
Richard Henderson
05a546429f target/arm: Introduce TRANS, TRANS_FEAT
Steal the idea for these leaf function expanders from PowerPC.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220527181907.189259-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-05-30 17:05:04 +01:00
Richard Henderson
2c2c65c01e target/arm: Use tcg_constant_i32 in translate.h
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-04-22 14:44:55 +01:00
Richard Henderson
2ab370873f target/arm: Change DisasContext.thumb to bool
Bool is a more appropriate type for this value.
Move the member down in the struct to keep the
bool type members together and remove a hole.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-04-22 14:44:54 +01:00
Richard Henderson
a3bc906f8e target/arm: Change DisasContext.aarch64 to bool
Bool is a more appropriate type for this value.
Move the member down in the struct to keep the
bool type members together and remove a hole.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-04-22 14:44:54 +01:00
Peter Maydell
2670221397 target/arm: Add TB flag for "MVE insns not predicated"
Our current codegen for MVE always calls out to helper functions,
because some byte lanes might be predicated.  The common case is that
in fact there is no predication active and all lanes should be
updated together, so we can produce better code by detecting that and
using the TCG generic vector infrastructure.

Add a TB flag that is set when we can guarantee that there is no
active MVE predication, and a bool in the DisasContext.  Subsequent
patches will use this flag to generate improved code for some
instructions.

In most cases when the predication state changes we simply end the TB
after that instruction.  For the code called from vfp_access_check()
that handles lazy state preservation and creating a new FP context,
we can usually avoid having to try to end the TB because luckily the
new value of the flag following the register changes in those
sequences doesn't depend on any runtime decisions.  We do have to end
the TB if the guest has enabled lazy FP state preservation but not
automatic state preservation, but this is an odd corner case that is
not going to be common in real-world code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210913095440.13462-4-peter.maydell@linaro.org
2021-09-21 16:28:27 +01:00
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
1e35cd9166 target/arm: Implement MVE VADD (floating-point)
Implement the MVE VADD (floating-point) insn.  Handling of this is
similar to the 2-operand integer insns, except that we must take care
to only update the floating point exception status if the least
significant bit of the predicate mask for each element is active.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-09-01 11:08:16 +01:00
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
3394116f47 target/arm: Implement MVE vector shift right by immediate insns
Implement the MVE vector shift right by immediate insns VSHRI and
VRSHRI.  As with Neon, we implement these by using helper functions
which perform left shifts but allow negative shift counts to indicate
right shifts.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-9-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
Peter Maydell
1d2386f70a target/arm: Implement MVE VMLALDAV
Implement the MVE VMLALDAV insn, which multiplies pairs of integer
elements, accumulating them into a 64-bit result in a pair of
general-purpose registers.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210617121628.20116-20-peter.maydell@linaro.org
2021-06-21 17:12:51 +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
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
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
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
a378206a20 target/arm: Move mode specific TB flags to tb->cs_base
Now that we have all of the proper macros defined, expanding
the CPUARMTBFlags structure and populating the two TB fields
is relatively simple.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-7-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
8a40fe5f1b target/arm: Rearrange {sve,fp}_check_access assert
We want to ensure that access is checked by the time we ask
for a specific fp/vector register.  We want to ensure that
we do not emit two lots of code to raise an exception.

But sometimes it's difficult to cleanly organize the code
such that we never pass through sve_check_access exactly once.
Allow multiple calls so long as the result is true, that is,
no exception to be raised.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200815013145.539409-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-08-28 10:02:47 +01:00
Peter Maydell
aaae563bc7 target/arm: Implement FPST_STD_F16 fpstatus
Architecturally, Neon FP16 operations use the "standard FPSCR" like
all other Neon operations.  However, this is defined in the Arm ARM
pseudocode as "a fixed value, except that FZ16 (and AHP) follow the
FPSCR bits". In QEMU, the softfloat float_status doesn't include
separate flush-to-zero for FP16 operations, so we must keep separate
fp_status for "Neon non-FP16" and "Neon fp16" operations, in the
same way we do already for the non-Neon "fp_status" vs "fp_status_f16".

Add the extra float_status field to the CPU state structure,
ensure it is correctly initialized and updated on FPSCR writes,
and make fpstatus_ptr(FPST_STD_F16) return a pointer to it.

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: 20200806104453.30393-4-peter.maydell@linaro.org
2020-08-24 10:15:11 +01:00
Peter Maydell
cdfb22bb73 target/arm: Replace A64 get_fpstatus_ptr() with generic fpstatus_ptr()
We currently have two versions of get_fpstatus_ptr(), which both take
an effectively boolean argument:
 * the one for A64 takes "bool is_f16" to distinguish fp16 from other ops
 * the one for A32/T32 takes "int neon" to distinguish Neon from other ops

This is confusing, and to implement ARMv8.2-FP16 the A32/T32 one will
need to make a four-way distinction between "non-Neon, FP16",
"non-Neon, single/double", "Neon, FP16" and "Neon, single/double".
The A64 version will then be a strict subset of the A32/T32 version.

To clean this all up, we want to go to a single implementation which
takes an enum argument with values FPST_FPCR, FPST_STD,
FPST_FPCR_F16, and FPST_STD_F16.  We rename the function to
fpstatus_ptr() so that unconverted code gets a compilation error
rather than silently passing the wrong thing to the new function.

This commit implements that new API, and converts A64 to use it:
 get_fpstatus_ptr(false) -> fpstatus_ptr(FPST_FPCR)
 get_fpstatus_ptr(true) -> fpstatus_ptr(FPST_FPCR_F16)

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: 20200806104453.30393-2-peter.maydell@linaro.org
2020-08-24 10:15:11 +01:00
Richard Henderson
5f716a8238 target/arm: Implement the LDGM, STGM, STZGM instructions
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-06-26 14:31:12 +01:00