Convert the VFP round-to-integer instructions VRINTR, VRINTZ and
VRINTX to decodetree.
These instructions were only introduced as part of the "VFP misc"
additions in v8A, so we check this. The old decoder's implementation
was incorrectly providing them even for v7A CPUs.
Backports commit e25155f55dc4abb427a88dfe58bbbc550fe7d643 from qemu
Convert the VCVTT and VCVTB instructions which convert from
f32 and f64 to f16 to decodetree.
Since we're no longer constrained to the old decoder's style
using cpu_F0s and cpu_F0d we can perform a direct 16 bit
store of the right half of the input single-precision register
rather than doing a load/modify/store sequence on the full
32 bits.
Backports commit cdfd14e86ab0b1ca29a702d13a8e4af2e902a9bf from qemu
Convert the VCVTT, VCVTB instructions that deal with conversion
from half-precision floats to f32 or 64 to decodetree.
Since we're no longer constrained to the old decoder's style
using cpu_F0s and cpu_F0d we can perform a direct 16 bit
load of the right half of the input single-precision register
rather than loading the full 32 bits and then doing a
separate shift or sign-extension.
Backports commit b623d803dda805f07aadcbf098961fde27315c19 from qemu
Convert the VFP comparison instructions to decodetree.
Note that comparison instructions should not honour the VFP
short-vector length and stride information: they are scalar-only
operations. This applies to all the 2-operand instructions except
for VMOV, VABS, VNEG and VSQRT. (In the old decoder this is
implemented via the "if (op == 15 && rn > 3) { veclen = 0; }" check.)
Backports commit 386bba2368842fc74388a3c1651c6c0c0c70adbd from qemu
Convert the VFP VABS instruction to decodetree.
Unlike the 3-op versions, we don't pass fpst to the VFPGen2OpSPFn or
VFPGen2OpDPFn because none of the operations which use this format
and support short vectors will need it.
Backports commit 90287e22c987e9840704345ed33d237cbe759dd9 from qemu
Convert the VFP fused multiply-add instructions (VFNMA, VFNMS,
VFMA, VFMS) to decodetree.
Note that in the old decode structure we were implementing
these to honour the VFP vector stride/length. These instructions
were introduced in VFPv4, and in the v7A architecture they
are UNPREDICTABLE if the vector stride or length are non-zero.
In v8A they must UNDEF if stride or length are non-zero, like
all VFP instructions; we choose to UNDEF always.
Backports commit d4893b01d23060845ee3855bc96626e16aad9ab5 from qemu
Convert the VFP VMLA instruction to decodetree.
This is the first of the VFP 3-operand data processing instructions,
so we include in this patch the code which loops over the elements
for an old-style VFP vector operation. The existing code to do this
looping uses the deprecated cpu_F0s/F0d/F1s/F1d TCG globals; since
we are going to be converting instructions one at a time anyway
we can take the opportunity to make the new loop use TCG temporaries,
which means we can do that conversion one operation at a time
rather than needing to do it all in one go.
We include an UNDEF check which was missing in the old code:
short-vector operations (with stride or length non-zero) were
deprecated in v7A and must UNDEF in v8A, so if the MVFR0 FPShVec
field does not indicate that support for short vectors is present
we UNDEF the operations that would use them. (This is a change
of behaviour for Cortex-A7, Cortex-A15 and the v8 CPUs, which
previously were all incorrectly allowing short-vector operations.)
Note that the conversion fixes a bug in the old code for the
case of VFP short-vector "mixed scalar/vector operations". These
happen where the destination register is in a vector bank but
but the second operand is in a scalar bank. For example
vmla.f64 d10, d1, d16 with length 2 stride 2
is equivalent to the pair of scalar operations
vmla.f64 d10, d1, d16
vmla.f64 d8, d3, d16
where the destination and first input register cycle through
their vector but the second input is scalar (d16). In the
old decoder the gen_vfp_F1_mul() operation uses cpu_F1{s,d}
as a temporary output for the multiply, which trashes the
second input operand. For the fully-scalar case (where we
never do a second iteration) and the fully-vector case
(where the loop loads the new second input operand) this
doesn't matter, but for the mixed scalar/vector case we
will end up using the wrong value for later loop iterations.
In the new code we use TCG temporaries and so avoid the bug.
This bug is present for all the multiply-accumulate insns
that operate on short vectors: VMLA, VMLS, VNMLA, VNMLS.
Note 2: the expression used to calculate the next register
number in the vector bank is not in fact correct; we leave
this behaviour unchanged from the old decoder and will
fix this bug later in the series.
Backports commit 266bd25c485597c94209bfdb3891c1d0c573c164 from qemu
Expand out the sequences in the new decoder VLDR/VSTR/VLDM/VSTM trans
functions which perform the memory accesses by going via the TCG
globals cpu_F0s and cpu_F0d, to use local TCG temps instead.
Backports commit 3993d0407dff7233e42f2251db971e126a0497e9 from qemu
Convert the VFP load/store multiple insns to decodetree.
This includes tightening up the UNDEF checking for pre-VFPv3
CPUs which only have D0-D15 : they now UNDEF for any access
to D16-D31, not merely when the smallest register in the
transfer list is in D16-D31.
This conversion does not try to share code between the single
precision and the double precision versions; this looks a bit
duplicative of code, but it leaves the door open for a future
refactoring which gets rid of the use of the "F0" registers
by inlining the various functions like gen_vfp_ld() and
gen_mov_F0_reg() which are hiding "if (dp) { ... } else { ... }"
conditionalisation.
Backports commit fa288de272c5c8a66d5eb683b123706a52bc7ad6 from qemu
Convert the VFP two-register transfer instructions to decodetree
(in the v8 Arm ARM these are the "Advanced SIMD and floating-point
64-bit move" encoding group).
Again, we expand out the sequences involving gen_vfp_msr() and
gen_msr_vfp().
Backports commit 81f681106eabe21c55118a5a41999fb7387fb714 from qemu
Convert the "single-precision" register moves to decodetree:
* VMSR
* VMRS
* VMOV between general purpose register and single precision
Note that the VMSR/VMRS conversions make our handling of
the "should this UNDEF?" checks consistent between the two
instructions:
* VMSR to MVFR0, MVFR1, MVFR2 now UNDEF from EL0
(previously was a nop)
* VMSR to FPSID now UNDEFs from EL0 or if VFPv3 or better
(previously was a nop)
* VMSR to FPINST and FPINST2 now UNDEF if VFPv3 or better
(previously would write to the register, which had no
guest-visible effect because we always UNDEF reads)
We also tighten up the decode: we were previously underdecoding
some SBZ or SBO bits.
The conversion of VMOV_single includes the expansion out of the
gen_mov_F0_vreg()/gen_vfp_mrs() and gen_mov_vreg_F0()/gen_vfp_msr()
sequences into the simpler direct load/store of the TCG temp via
neon_{load,store}_reg32(): we know in the new function that we're
always single-precision, we don't need to use the old-and-deprecated
cpu_F0* TCG globals, and we don't happen to have the declaration of
gen_vfp_msr() and gen_vfp_mrs() at the point in the file where the
new function is.
Backports commit a9ab50011aeda2dd012da99069e078379315ea18 from qemu
Convert the "double-precision" register moves to decodetree:
this covers VMOV scalar-to-gpreg, VMOV gpreg-to-scalar and VDUP.
Note that the conversion process has tightened up a few of the
UNDEF encoding checks: we now correctly forbid:
* VMOV-to-gpr with U:opc1:opc2 == 10x00 or x0x10
* VMOV-from-gpr with opc1:opc2 == 0x10
* VDUP with B:E == 11
* VDUP with Q == 1 and Vn<0> == 1
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
The accesses of elements < 32 bits could be improved by doing
direct ld/st of the right size rather than 32-bit read-and-shift
or read-modify-write, but we leave this for later cleanup,
since this series is generally trying to stick to fixing
the decode.
Backports commit 9851ed9269d214c0c6feba960dd14ff09e6c34b4 from qemu
The current VFP code has two different idioms for
loading and storing from the VFP register file:
1 using the gen_mov_F0_vreg() and similar functions,
which load and store to a fixed set of TCG globals
cpu_F0s, CPU_F0d, etc
2 by direct calls to tcg_gen_ld_f64() and friends
We want to phase out idiom 1 (because the use of the
fixed globals is a relic of a much older version of TCG),
but idiom 2 is quite longwinded:
tcg_gen_ld_f64(tmp, cpu_env, vfp_reg_offset(true, reg))
requires us to specify the 64-bitness twice, once in
the function name and once by passing 'true' to
vfp_reg_offset(). There's no guard against accidentally
passing the wrong flag.
Instead, let's move to a convention of accessing 64-bit
registers via the existing neon_load_reg64() and
neon_store_reg64(), and provide new neon_load_reg32()
and neon_store_reg32() for the 32-bit equivalents.
Implement the new functions and use them in the code in
translate-vfp.inc.c. We will convert the rest of the VFP
code as we do the decodetree conversion in subsequent
commits.
Backports commit 160f3b64c5cc4c8a09a1859edc764882ce6ad6bf from qemu
Move the trans_*() functions we've just created from translate.c
to translate-vfp.inc.c. This is pure code motion with no textual
changes (this can be checked with 'git show --color-moved').
Backports commit f7bbb8f31f0761edbf0c64b7ab3c3f49c13612ea from qemu
Convert the VCVTA/VCVTN/VCVTP/VCVTM instructions to decodetree.
trans_VCVT() is temporarily left in translate.c.
Backports commit c2a46a914cd5c38fd0ee57ff0befc1c5bde27bcf from qemu
Convert the VRINTA/VRINTN/VRINTP/VRINTM instructions to decodetree.
Again, trans_VRINT() is temporarily left in translate.c.
Backports commit e3bb599d16e4678b228d80194cee328f894b1ceb from qemu
Convert the VMINNM and VMAXNM instructions to decodetree.
As with VSEL, we leave the trans_VMINMAXNM() function
in translate.c for the moment.
Backports commit f65988a1efdb42f9058db44297591491842e697c from qemu
Convert the VSEL instructions to decodetree.
We leave trans_VSEL() in translate.c for now as this allows
the patch to show just the changes from the old handle_vsel().
In the old code the check for "do D16-D31 exist" was hidden in
the VFP_DREG macro, and assumed that VFPv3 always implied that
D16-D31 exist. In the new code we do the correct ID register test.
This gives identical behaviour for most of our CPUs, and fixes
previously incorrect handling for Cortex-R5F, Cortex-M4 and
Cortex-M33, which all implement VFPv3 or better with only 16
double-precision registers.
Backports commit b3ff4b87b4ae08120a51fe12592725e1dca8a085 from qemu
At the moment our -cpu max for AArch32 supports VFP short-vectors
because we always implement them, even for CPUs which should
not have them. The following commits are going to switch to
using the correct ID-register-check to enable or disable short
vector support, so we need to turn it on explicitly for -cpu max,
because Cortex-A15 doesn't implement it.
We don't enable this for the AArch64 -cpu max, because the v8A
architecture never supports short-vectors.
Backports commit 973751fd798d41402d34f9f705c0c6d1633d0cda from qemu
The Cortex-R5F initfn was not correctly setting up the MVFR
ID register values. Fill these in, since some subsequent patches
will use ID register checks rather than CPU feature bit checks.
Backports commit 3de79d335c9aa7d726865e3933d9b21781032183 from qemu
Factor out the VFP access checking code so that we can use it in the
leaf functions of the decodetree decoder.
We call the function full_vfp_access_check() so we can keep
the more natural vfp_access_check() for a version which doesn't
have the 'ignore_vfp_enabled' flag -- that way almost all VFP
insns will be able to use vfp_access_check(s) and only the
special-register access function will have to use
full_vfp_access_check(s, ignore_vfp_enabled).
Backports commit 06db8196bba34776829020192ed623a0b22e6557 from qemu
Add the infrastructure for building and invoking a decodetree decoder
for the AArch32 VFP encodings. At the moment the new decoder covers
nothing, so we always fall back to the existing hand-written decode.
We need to have one decoder for the unconditional insns and one for
the conditional insns, as otherwise the patterns for conditional
insns would incorrectly match against the unconditional ones too.
Since translate.c is over 14,000 lines long and we're going to be
touching pretty much every line of the VFP code as part of the
decodetree conversion, we create a new translate-vfp.inc.c to hold
the code which deals with VFP in the new scheme. It should be
possible to convert this into a standalone translation unit
eventually, but the conversion process will be much simpler if we
simply #include it midway through translate.c to start with.
Backports commit 78e138bc1f672c145ef6ace74617db00eebaa2ba from qemu
The ARM pseudocode installs the error_code into the original
pointer, not the encrypted pointer. The difference applies
within the 7 bits of pac data; the result should be the sign
extension of bit 55.
Add a testcase to that effect.
Backports commit d67ebada159148bfdfde84871338738e4465e985 from qemu
The NSACR register allows secure code to configure the FPU
to be inaccessible to non-secure code. If the NSACR.CP10
bit is set then:
* NS accesses to the FPU trap as UNDEF (ie to NS EL1 or EL2)
* CPACR.{CP10,CP11} behave as if RAZ/WI
* HCPTR.{TCP11,TCP10} behave as if RAO/WI
Note that we do not implement the NSACR.NSASEDIS bit which
gates only access to Advanced SIMD, in the same way that
we don't implement the equivalent CPACR.ASEDIS and HCPTR.TASE.
Backports commit fc1120a7f5f2d4b601003205c598077d3eb11ad2 from qemu
Nothing in there so far, but all of the plumbing done
within the target ArchCPU state.
Backports commit 5b146dc716cfd247f99556c04e6e46fbd67565a0 from qemu
Now that we have ArchCPU, we can define this generically,
in the one place that needs it.
Backports commit 677c4d69ac21961e76a386f9bfc892a44923acc0 from qemu
Cleanup in the boilerplate that each target must define.
Replace arm_env_get_cpu with env_archcpu. The combination
CPU(arm_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 2fc0cc0e1e034582f4718b1a2d57691474ccb6aa from qemu
Now that we have both ArchCPU and CPUArchState, we can define
this generically instead of via macro in each target's cpu.h.
Backports commit 29a0af618ddd21f55df5753c3e16b0625f534b3c from qemu
For all targets, into this new file move TARGET_LONG_BITS,
TARGET_PAGE_BITS, TARGET_PHYS_ADDR_SPACE_BITS,
TARGET_VIRT_ADDR_SPACE_BITS, and NB_MMU_MODES.
Include this new file from exec/cpu-defs.h.
This now removes the somewhat odd requirement that target/arch/cpu.h
defines TARGET_LONG_BITS before including exec/cpu-defs.h, so push the
bulk of the includes within target/arch/cpu.h to the top.
Backports commit 74433bf083b0766aba81534f92de13194f23ff3e from qemu
Commit 89e68b575 "target/arm: Use vector operations for saturation"
causes this abort() when booting QEMU ARM with a Cortex-A15:
0 0x00007ffff4c2382f in raise () at /usr/lib/libc.so.6
1 0x00007ffff4c0e672 in abort () at /usr/lib/libc.so.6
2 0x00005555559c1839 in disas_neon_data_insn (insn=<optimized out>, s=<optimized out>) at ./target/arm/translate.c:6673
3 0x00005555559c1839 in disas_neon_data_insn (s=<optimized out>, insn=<optimized out>) at ./target/arm/translate.c:6386
4 0x00005555559cd8a4 in disas_arm_insn (insn=4081107068, s=0x7fffe59a9510) at ./target/arm/translate.c:9289
5 0x00005555559cd8a4 in arm_tr_translate_insn (dcbase=0x7fffe59a9510, cpu=<optimized out>) at ./target/arm/translate.c:13612
6 0x00005555558d1d39 in translator_loop (ops=0x5555561cc580 <arm_translator_ops>, db=0x7fffe59a9510, cpu=0x55555686a2f0, tb=<optimized out>, max_insns=<optimized out>) at ./accel/tcg/translator.c:96
7 0x00005555559d10d4 in gen_intermediate_code (cpu=cpu@entry=0x55555686a2f0, tb=tb@entry=0x7fffd7840080 <code_gen_buffer+126091347>, max_insns=max_insns@entry=512) at ./target/arm/translate.c:13901
8 0x00005555558d06b9 in tb_gen_code (cpu=cpu@entry=0x55555686a2f0, pc=3067096216, cs_base=0, flags=192, cflags=-16252928, cflags@entry=524288) at ./accel/tcg/translate-all.c:1736
9 0x00005555558ce467 in tb_find (cf_mask=524288, tb_exit=1, last_tb=0x7fffd783e640 <code_gen_buffer+126084627>, cpu=0x1) at ./accel/tcg/cpu-exec.c:407
10 0x00005555558ce467 in cpu_exec (cpu=cpu@entry=0x55555686a2f0) at ./accel/tcg/cpu-exec.c:728
11 0x000055555588b0cf in tcg_cpu_exec (cpu=0x55555686a2f0) at ./cpus.c:1431
12 0x000055555588d223 in qemu_tcg_cpu_thread_fn (arg=0x55555686a2f0) at ./cpus.c:1735
13 0x000055555588d223 in qemu_tcg_cpu_thread_fn (arg=arg@entry=0x55555686a2f0) at ./cpus.c:1709
14 0x0000555555d2629a in qemu_thread_start (args=<optimized out>) at ./util/qemu-thread-posix.c:502
15 0x00007ffff4db8a92 in start_thread () at /usr/lib/libpthread.
This patch ensures that we don't hit the abort() in the second switch
case in disas_neon_data_insn() as we will return from the first case.
Backports commit 2f143d3ad1c05e91cf2cdf5de06d59a80a95e6c8 from qemu
The mask implied by the extract is redundant with the one
implied by the deposit. Also, fix spelling of BFXIL.
Backports commit 87eb65a3c45c788a309986d48170a54a0d1c0705 from qemu
Use the newly introduced infrastructure for guest random numbers.
Backports commit de390645675966cce113bf5394445bc1f8d07c85 from qemu
(with the actual RNG portion disabled to preserve determinism for the
time being).
Most of the existing users would continue around a loop which
would fault the tlb entry in via a normal load/store.
But for AArch64 SVE we have an existing emulation bug wherein we
would mark the first element of a no-fault vector load as faulted
(within the FFR, not via exception) just because we did not have
its address in the TLB. Now we can properly only mark it as faulted
if there really is no valid, readable translation, while still not
raising an exception. (Note that beyond the first element of the
vector, the hardware may report a fault for any reason whatsoever;
with at least one element loaded, forward progress is guaranteed.)
Backports commit 4811e9095c0491bc6f5450e5012c9c4796b9e59d from qemu
We can now use the CPUClass hook instead of a named function.
Create a static tlb_fill function to avoid other changes within
cputlb.c. This also isolates the asserts within. Remove the
named tlb_fill function from all of the targets.
Backports commit c319dc13579a92937bffe02ad2c9f1a550e73973 from qemu
Remove a function of the same name from target/arm/.
Use a branchless implementation of abs gleaned from gcc.
Backports commit ff1f11f7f8710a768f9313f24bd7f509d3db27e5 from qemu
Replace the single opcode in .opc with a null-terminated
array in .opt_opc. We still require that all opcodes be
used with the same .vece.
Validate the contents of this list with CONFIG_DEBUG_TCG.
All tcg_gen_*_vec functions will check any list active
during .fniv expansion. Swap the active list in and out
as we expand other opcodes, or take control away from the
front-end function.
Convert all existing vector aware front ends.
Backports commit 53229a7703eeb2bbe101a19a33ef22aaf960c65b from qemu
Currently the dc_zva helper function uses a variable length
array. In fact we know (as the comment above remarks) that
the length of this array is bounded because the architecture
limits the block size and QEMU limits the target page size.
Use a fixed array size and assert that we don't run off it.
Backports commit 63159601fb3e396b28da14cbb71e50ed3f5a0331 from qemu
In the M-profile architecture, if the CPU implements the DSP extension
then the XPSR has GE bits, in the same way as the A-profile CPSR. When
we added DSP extension support we forgot to add support for reading
and writing the GE bits, which are stored in env->GE. We did put in
the code to add XPSR_GE to the mask of bits to update in the v7m_msr
helper, but forgot it in v7m_mrs. We also must not allow the XPSR we
pull off the stack on exception return to set the nonexistent GE bits.
Correct these errors:
* read and write env->GE in xpsr_read() and xpsr_write()
* only set GE bits on exception return if DSP present
* read GE bits for MRS if DSP present
Backports commit f1e2598c46d480c9e21213a244bc514200762828 from qemu
Thereby decoupling the resulting translated code from the current state
of the system.
Backports commit 2399d4e7cec22ecf1c51062d2ebfd45220dbaace from qemu
The M-profile architecture floating point system supports
lazy FP state preservation, where FP registers are not
pushed to the stack when an exception occurs but are instead
only saved if and when the first FP instruction in the exception
handler is executed. Implement this in QEMU, corresponding
to the check of LSPACT in the pseudocode ExecuteFPCheck().
Backports commit e33cf0f8d8c9998a7616684f9d6aa0d181b88803 from qemu
Pushing registers to the stack for v7M needs to handle three cases:
* the "normal" case where we pend exceptions
* an "ignore faults" case where we set FSR bits but
do not pend exceptions (this is used when we are
handling some kinds of derived exception on exception entry)
* a "lazy FP stacking" case, where different FSR bits
are set and the exception is pended differently
Implement this by changing the existing flag argument that
tells us whether to ignore faults or not into an enum that
specifies which of the 3 modes we should handle.
Backports commit a356dacf647506bccdf8ecd23574246a8bf615ac from qemu
In the v7M architecture, if an exception is generated in the process
of doing the lazy stacking of FP registers, the handling of
possible escalation to HardFault is treated differently to the normal
approach: it works based on the saved information about exception
readiness that was stored in the FPCCR when the stack frame was
created. Provide a new function armv7m_nvic_set_pending_lazyfp()
which pends exceptions during lazy stacking, and implements
this logic.
This corresponds to the pseudocode TakePreserveFPException().
Backports the relevant parts of commit
a99ba8ab1601904e0fa20325192fc850362ce80e from qemu
Add a new helper function which returns the MMU index to use
for v7M, where the caller specifies all of the security
state, privilege level and whether the execution priority
is negative, and reimplement the existing
arm_v7m_mmu_idx_for_secstate_and_priv() in terms of it.
We are going to need this for the lazy-FP-stacking code.
Backports commit fa6252a988dbe440cd6087bf93cbe0887f0c401b from qemu
The M-profile FPCCR.ASPEN bit indicates that automatic floating-point
context preservation is enabled. Before executing any floating-point
instruction, if FPCCR.ASPEN is set and the CONTROL FPCA/SFPA bits
indicate that there is no active floating point context then we
must create a new context (by initializing FPSCR and setting
FPCA/SFPA to indicate that the context is now active). In the
pseudocode this is handled by ExecuteFPCheck().
Implement this with a new TB flag which tracks whether we
need to create a new FP context.
Backports commit 6000531e19964756673a5f4b694a649ef883605a from qemu
The M-profile FPCCR.S bit indicates the security status of
the floating point context. In the pseudocode ExecuteFPCheck()
function it is unconditionally set to match the current
security state whenever a floating point instruction is
executed.
Implement this by adding a new TB flag which tracks whether
FPCCR.S is different from the current security state, so
that we only need to emit the code to update it in the
less-common case when it is not already set correctly.
Note that we will add the handling for the other work done
by ExecuteFPCheck() in later commits.
Backports commit 6d60c67a1a03be32c3342aff6604cdc5095088d1 from qemu
We are close to running out of TB flags for AArch32; we could
start using the cs_base word, but before we do that we can
economise on our usage by sharing the same bits for the VFP
VECSTRIDE field and the XScale XSCALE_CPAR field. This
works because no XScale CPU ever had VFP.
Backports commit ea7ac69d124c94c6e5579145e727adec9ccbefef from qemu
Move the NS TBFLAG down from bit 19 to bit 6, which has not
been used since commit c1e3781090b9d36c60 in 2015, when we
started passing the entire MMU index in the TB flags rather
than just a 'privilege level' bit.
This rearrangement is not strictly necessary, but means that
we can put M-profile-only bits next to each other rather
than scattered across the flag word.
Backports commit 7fbb535f7aeb22896fedfcf18a1eeff48165f1d7 from qemu
Handle floating point registers in exception return.
This corresponds to pseudocode functions ValidateExceptionReturn(),
ExceptionReturn(), PopStack() and ConsumeExcStackFrame().
Backports commit 6808c4d2d2826920087533f517472c09edc7b0d2 from qemu
The magic value pushed onto the callee stack as an integrity
check is different if floating point is present.
Backports commit 0dc51d66fcfcc4c72011cdafb401fd876ca216e7 from qemu
The TailChain() pseudocode specifies that a tail chaining
exception should sanitize the excReturn all-ones bits and
(if there is no FPU) the excReturn FType bits; we weren't
doing this.
Backports commit 60fba59a2f9a092a44b688df5d058cdd6dd9c276 from qemu
For v8M floating point support, transitions from Secure
to Non-secure state via BLNS and BLXNS must clear the
CONTROL.SFPA bit. (This corresponds to the pseudocode
BranchToNS() function.)
Backports commit 3cd6726f0ba7cc77342ee721bd86094e13b2a42a from qemu
Implement the code which updates the FPCCR register on an
exception entry where we are going to use lazy FP stacking.
We have to defer to the NVIC to determine whether the
various exceptions are currently ready or not.
Backports commit b593c2b81287040ab6f452afec6281e2f7ee487b from qemu
Handle floating point registers in exception entry.
This corresponds to the FP-specific parts of the pseudocode
functions ActivateException() and PushStack().
We defer the code corresponding to UpdateFPCCR() to a later patch.
Backports commit 0ed377a8013f40653a83f6ad2c9693897522d7dc from qemu
Currently the code in v7m_push_stack() which detects a violation
of the v8M stack limit simply returns early if it does so. This
is OK for the current integer-only code, but won't work for the
floating point handling we're about to add. We need to continue
executing the rest of the function so that we check for other
exceptions like not having permission to use the FPU and so
that we correctly set the FPCCR state if we are doing lazy
stacking. Refactor to avoid the early return.
Backports commit 3432c79a4e7345818d2defcf9e61a1bcb2907f9f from qemu
The M-profile CONTROL register has two bits -- SFPA and FPCA --
which relate to floating-point support, and should be RES0 otherwise.
Handle them correctly in the MSR/MRS register access code.
Neither is banked between security states, so they are stored
in v7m.control[M_REG_S] regardless of current security state.
Backports commit 2e1c5bcd32014c9ede1b604ae6c2c653de17fc53 from qemu
If the floating point extension is present, then the SG instruction
must clear the CONTROL_S.SFPA bit. Implement this.
(On a no-FPU system the bit will always be zero, so we don't need
to make the clearing of the bit conditional on ARM_FEATURE_VFP.)
Backports commit 1702071302934af77a072b7ee7c5eadc45b37573 from qemu
Correct the decode of the M-profile "coprocessor and
floating-point instructions" space:
* op0 == 0b11 is always unallocated
* if the CPU has an FPU then all insns with op1 == 0b101
are floating point and go to disas_vfp_insn()
For the moment we leave VLLDM and VLSTM as NOPs; in
a later commit we will fill in the proper implementation
for the case where an FPU is present.
Backports commit 8859ba3c9625e7ceb5599f457a344bcd7c5e112b from qemu
Like AArch64, M-profile floating point has no FPEXC enable
bit to gate floating point; so always set the VFPEN TB flag.
M-profile also has CPACR and NSACR similar to A-profile;
they behave slightly differently:
* the CPACR is banked between Secure and Non-Secure
* if the NSACR forces a trap then this is taken to
the Secure state, not the Non-Secure state
Honour the CPACR and NSACR settings. The NSACR handling
requires us to borrow the exception.target_el field
(usually meaningless for M profile) to distinguish the
NOCP UsageFault taken to Secure state from the more
usual fault taken to the current security state.
Backports commit d87513c0abcbcd856f8e1dee2f2d18903b2c3ea2 from qemu
The only "system register" that M-profile floating point exposes
via the VMRS/VMRS instructions is FPSCR, and it does not have
the odd special case for rd==15. Add a check to ensure we only
expose FPSCR.
Backports commit ef9aae2522c22c05df17dd898099dd5c3f20d688 from qemu
The M-profile floating point support has three associated config
registers: FPCAR, FPCCR and FPDSCR. It also makes the registers
CPACR and NSACR have behaviour other than reads-as-zero.
Add support for all of these as simple reads-as-written registers.
We will hook up actual functionality later.
The main complexity here is handling the FPCCR register, which
has a mix of banked and unbanked bits.
Note that we don't share storage with the A-profile
cpu->cp15.nsacr and cpu->cp15.cpacr_el1, though the behaviour
is quite similar, for two reasons:
* the M profile CPACR is banked between security states
* it preserves the invariant that M profile uses no state
inside the cp15 substruct
Backports commit d33abe82c7c9847284a23e575e1078cccab540b5 from qemu
Enforce that for M-profile various FPSCR bits which are RES0 there
but have defined meanings on A-profile are never settable. This
ensures that M-profile code can't enable the A-profile behaviour
(notably vector length/stride handling) by accident.
Backports commit 5bcf8ed9401e62c73158ba110864ee1375558bf7 from qemu
In order to handle TB's that translate to too much code, we
need to place the control of the length of the translation
in the hands of the code gen master loop.
Backports commit 8b86d6d25807e13a63ab6ea879f976b9f18cc45a from qemu
This wasn't subtracting the size of the instruction off the PC like how
the ARM mode tracing was performing the tracing. This simplifies it and
makes the behavior identical.
Allows non-AArch64 environments to always access coprocessors initially.
Removes the need to do avoidable register management when testing
floating-point code.
cortex-a7 and cortex-a15 have pmus (PMUv2) and they advertise
them in ID_DFR0. Let's allow them to function. This also enables
the pmu cpu property to work with these cpu types, i.e. we can
now do '-cpu cortex-a15,pmu=off' to remove the pmu.
Backports commit a46118fc16537a593119e5b316052a98514046bb from qemu
Fix a QEMU NULL derefence that occurs when the guest attempts to
enable PMU counters with a non-v8 cpu model or a v8 cpu model
which has not configured a PMU.
Backports commit cbbb3041fe2f57a475cef5d6b0ef836118aad106 from qemu
The second word has been loaded from the unincremented
address since the first commit.
Backports commit a036f5302c13634f3d375615b2949fd1fa1657b6 from qemu
These instructions do not trap when SVE is disabled in EL0,
causing them to be executed with wrong size information.
Backports commit 5de56742a3c91de3d646326bec43a989bba83ca4 from qemu
Some generic arch timer registers are Config-RW in the EL0,
which means the EL0 exception level can have write permission
if it is appropriately configured.
When VM access registers, QEMU firstly checks whether they have RW
permission, then check whether it is appropriately configured.
If they are defined to read only in EL0, even though they have been
appropriately configured, they still do not have write permission.
So need to add the write permission according to ARMV8 spec when
define it.
Backports commit daf1dc5f82cefe2a57f184d5053e8b274ad2ba9a from qemu
These changes were mostly made in upstream unicorn for what I can guess,
was to support old versions of MSVC's compiler.
This is also a pain to maintain, since everything needs to be done
manually and can be a source of errors. It also makes it take more work
than it needs to, to backport changes from qemu.
Because of that, this change restores Qemu's organization of the
coprocessor registers.
This decoding more closely matches the ARMv8.4 Table C4-6,
Encoding table for Data Processing - Register Group.
In particular, op2 == 0 is now more than just Add/sub (with carry).
Backports commit 2fba34f70d9a81bab56e61bb99a4d6632bdfe531 from qemu
We do not need an out-of-line helper for manipulating bits in pstate.
While changing things, share the implementation of gen_ss_advance.
Backports commit 22ac3c49641f6eed93dca5b852030b4d3eacf6c4 from qemu
The EL0+UMA check is unique to DAIF. While SPSel had avoided the
check by nature of already checking EL >= 1, the other post v8.0
extensions to MSR (imm) allow EL0 and do not require UMA. Avoid
the unconditional write to pc and use raise_exception_ra to unwind.
Backports commit ff730e9666a716b669ac4a8ca7c521177d1d2b15 from qemu
Minimize the number of places that will need updating when
the virtual host extensions are added.
Backports commit 64e40755cd41fbe8cd266cf387e42ddc57a449ef from qemu
Found by inspection: Rn is the base register against which the
load began; I is the register within the mask being processed.
The exception return should of course be processed from the loaded PC.
Backports commit 9d090d17234058f55c3c439d285db78c94d7d4de from qemu
Previously we'd be checking prior to the actual decoding if we were at
the ending address. This worked fine using the old model of the
translation process in qemu. However, this causes the wrong behavior to
occur in both ARM and Thumb/Thumb-2 modes using the newer translator
model.
Given the translator itself checks for the end address already, this
needs to be placed within arm_post_translate_insn().
This prevents the emulation process being off-by-one as well when it
comes to actually executing the instructions.
1. Create an enum name for the IPSR register.
2. Implement read and write of the IPSR via the xpsr helper functions.
Fixes#1065
Backports commit 6c319941a5462ee3a4af4593c371f5674394d6ce from unicorn.
Note that float16_to_float32 rightly squashes SNaN to QNaN.
But of course pickNaNMulAdd, for ARM, selects SNaNs first.
So we have to preserve SNaN long enough for the correct NaN
to be selected. Thus float16_to_float32_by_bits.
Backports commit a4e943a716d5fac923d82df3eabc65d1e3624019 from qemu
There is a set of VFP instructions which we implement in
disas_vfp_v8_insn() and gate on the ARM_FEATURE_V8 bit.
These were all first introduced in v8 for A-profile, but in
M-profile they appeared in v7M. Gate them on the MVFR2
FPMisc field instead, and rename the function appropriately.
Backports commit c0c760afe800b60b48c80ddf3509fec413594778 from qemu
Instead of gating the A32/T32 FP16 conversion instructions on
the ARM_FEATURE_VFP_FP16 flag, switch to our new approach of
looking at ID register bits. In this case MVFR1 fields FPHP
and SIMDHP indicate the presence of these insns.
This change doesn't alter behaviour for any of our CPUs.
Backports commit 602f6e42cfbfe9278be34e9b91d2ceb695837e02 from qemu
There are lots of special cases within these insns. Split the
major argument decode/loading/saving into no_output (compares),
rd_is_dp, and rm_is_dp.
We still need to special case argument load for compare (rd as
input, rm as zero) and vcvt fixed (rd as input+output), but lots
of special cases do disappear.
Now that we have a full switch at the beginning, hoist the ISA
checks from the code generation.
Backports commit e80941bd64cc388554770fd72334e9e7d459a1ef from qemu
Move all of the fp helpers out of helper.c into a new file.
This is code movement only. Since helper.c has no copyright
header, take the one from cpu.h for the new file.
Backports commit 37356079fcdb34e13abbed8ea0c00ca880c31247 from qemu
For opcodes 0-5, move some if conditions into the structure
of a switch statement. For opcodes 6 & 7, decode everything
at once with a second switch.
Backports commit 3c3ff68492c2d00bd8cb39ed2d02bdaf5caf5cb8 from qemu
This was introduced by
commit bf8d09694ccc07487cd73d7562081fdaec3370c8
target/arm: Don't clear supported PMU events when initializing PMCEID1
and identified by Coverity (CID 1398645).
Backports commit 67da43d668320e1bcb0a0195aaf2de4ff2a001a0 from qemu
The "background region" for a v8M MPU is a default which will be used
(if enabled, and if the access is privileged) if the access does
not match any specific MPU region. We were incorrectly using it
always (by putting the condition at the wrong nesting level). This
meant that we would always return the default background permissions
rather than the correct permissions for a specific region, and also
that we would not return the right information in response to a
TT instruction.
Move the check for the background region to the same place in the
logic as the equivalent v8M MPUCheck() pseudocode puts it.
This in turn means we must adjust the condition we use to detect
matches in multiple regions to avoid false-positives.
Backports commit cff21316c666c8053b1f425577e324038d0ca30d from qemu
Fortunately, the functions affected are so far only called from SVE,
so there is no tail to be cleared. But as we convert more of AdvSIMD
to gvec, this will matter.
Backports commit d8efe78e8039511b95c23d75bb48eca6873fbb0f from qemu
For same-sign saturation, we have tcg vector operations. We can
compute the QC bit by comparing the saturated value against the
unsaturated value.
Backports commit 89e68b575e138d0af1435f11a8ffcd8779c237bd from qemu
Change the representation of this field such that it is easy
to set from vector code.
Backports commit a4d5846245c5e029e5aa3945a9bda1de1c3fedbf from qemu
Given that we mask bits properly on set, there is no reason
to mask them again on get. We failed to clear the exception
status bits, 0x9f, which means that the wrong value would be
returned on get. Except in the (probably normal) case in which
the set clears all of the bits.
Simplify the code in set to also clear the RES0 bits.
Backports commit 18aaa59c622208743565307668a2100ab24f7de9 from qemu
Minimize the code within a macro by splitting out a helper function.
Use deposit32 instead of manual bit manipulation.
Backports commit 55a889456ef78f3f9b8eae9846c2f1453b1dd77b from qemu
The 32-bit PMIN/PMAX has been decomposed to scalars,
and so can be trivially expanded inline.
Backports commit 9ecd3c5c1651fa7f9adbedff4806a2da0b50490c from qemu
Since we're now handling a == b generically, we no longer need
to do it by hand within target/arm/.
Backports commit 2900847ff4c862887af750935a875059615f509a from qemu
There are a whole bunch more registers in the CPUID space which are
currently not used but are exposed as RAZ. To avoid too much
duplication we expand ARMCPRegUserSpaceInfo to understand glob
patterns so we only need one entry to tweak whole ranges of registers.
Backports commit d040242effe47850060d2ef1c461ff637d88a84d from qemu
As this is a single register we could expose it with a simple ifdef
but we use the existing modify_arm_cp_regs mechanism for consistency.
Backports commit 522641660c3de64ed8322b8636c58625cd564a3f from qemu
