MSR IA32_CORE_CAPABILITY is a feature-enumerating MSR, which only
enumerates the feature split lock detection (via bit 5) by now.
The existence of MSR IA32_CORE_CAPABILITY is enumerated by CPUID.7_0:EDX[30].
The latest kernel patches about them can be found here:
https://lkml.org/lkml/2019/4/24/1909
Backports commit 597360c0d8ebda9ca6f239db724a25bddec62b2f from qemu
In commit 1120827fa182f0e7622 we accidentally put the
"UNDEF unless FPU has double-precision support" check in
the single-precision VFM function. Put it in the dp
function where it belongs.
Backports commit 34bea4edb9bbe8edf4b8606276482acdff5ca58b from qemu
The architecture permits FPUs which have only single-precision
support, not double-precision; Cortex-M4 and Cortex-M33 are
both like that. Add the necessary checks on the MVFR0 FPDP
field so that we UNDEF any double-precision instructions on
CPUs like this.
Note that even if FPDP==0 the insns like VMOV-to/from-gpreg,
VLDM/VSTM, VLDR/VSTR which take double precision registers
still exist.
Backports commit 1120827fa182f0e76226df7ffe7a86598d1df54f from qemu
In several places cut and paste errors meant we were using the wrong
type for the 'arg' struct in trans_ functions called by the
decodetree decoder, because we were using the _sp version of the
struct in the _dp function. These were harmless, because the two
structs were identical and so decodetree made them typedefs of the
same underlying structure (and we'd have had a compile error if they
were not harmless), but we should clean them up anyway.
Backports commit 83655223ac6143a563e981906ce13fd6f2cfbefd from qemu
Remove the now unused TCG globals cpu_F0s, cpu_F0d, cpu_F1s, cpu_F1d.
cpu_M0 is still used by the iwmmxt code, and cpu_V0 and
cpu_V1 are used by both iwmmxt and Neon.
Backports commit d9eea52c67c04c58ecceba6ffe5a93d1d02051fa from qemu
Remove some old constructns from NEON_2RM_VCVT_F16_F32 code:
* don't use CPU_F0s
* don't use tcg_gen_st_f32
Backports commit b66f6b9981004bbf120b8d17c20f92785179bdf2 from qemu
Remove some old constructs from NEON_2RM_VCVT_F16_F32 code:
* don't use cpu_F0s
* don't use tcg_gen_ld_f32
Backports commit 58f2682eee738e8890f9cfe858e0f4f68b00d45d from qemu
Stop using cpu_F0s for the Neon f32/s32 VCVT operations.
Since this is the last user of cpu_F0s in the Neon 2rm-op
loop, we can remove the handling code for it too.
Backports commit 60737ed5785b9c1c6f1c85575dfdd1e9eec91878 from qemu
Where Neon instructions are floating point operations, we
mostly use the old VFP utility functions like gen_vfp_abs()
which work on the TCG globals cpu_F0s and cpu_F1s. The
Neon for-each-element loop conditionally loads the inputs
into either a plain old TCG temporary for most operations
or into cpu_F0s for float operations, and similarly stores
back either cpu_F0s or the temporary.
Switch NEON_2RM_VABS_F away from using cpu_F0s, and
update neon_2rm_is_float_op() accordingly.
Backports commit fd8a68cdcf81d70eebf866a132e9780d4108da9c from qemu
The AArch32 VMOV (immediate) instruction uses the same VFP encoded
immediate format we already handle in vfp_expand_imm(). Use that
function rather than hand-decoding it.
Backports commit 9bee50b498410ed6466018b26464d7384c7879e9 from qemu
We want to use vfp_expand_imm() in the AArch32 VFP decode;
move it from the a64-only header/source file to the
AArch32 one (which is always compiled even for AArch64).
Backports commit d6a092d479333b5f20a647a912a31b0102d37335 from qemu
For VFP short vectors, the VFP registers are divided into a
series of banks: for single-precision these are s0-s7, s8-s15,
s16-s23 and s24-s31; for double-precision they are d0-d3,
d4-d7, ... d28-d31. Some banks are "scalar" meaning that
use of a register within them triggers a pure-scalar or
mixed vector-scalar operation rather than a full vector
operation. The scalar banks are s0-s7, d0-d3 and d16-d19.
When using a bank as part of a vector operation, we
iterate through it, increasing the register number by
the specified stride each time, and wrapping around to
the beginning of the bank.
Unfortunately our calculation of the "increment" part of this
was incorrect:
vd = ((vd + delta_d) & (bank_mask - 1)) | (vd & bank_mask)
will only do the intended thing if bank_mask has exactly
one set high bit. For instance for doubles (bank_mask = 0xc),
if we start with vd = 6 and delta_d = 2 then vd is updated
to 12 rather than the intended 4.
This only causes problems in the unlikely case that the
starting register is not the first in its bank: if the
register number doesn't have to wrap around then the
expression happens to give the right answer.
Fix this bug by abstracting out the "check whether register
is in a scalar bank" and "advance register within bank"
operations to utility functions which use the right
bit masking operations
Backports commit 18cf951af9a27ae573a6fa17f9d0c103f7b7679b from qemu
Convert the float-to-integer VCVT instructions to decodetree.
Since these are the last unconverted instructions, we can
delete the old decoder structure entirely now.
Backports commit 3111bfc2da6ba0c8396dc97ca479942d711c6146 from qemu
Convert the VCVT (between floating-point and fixed-point) instructions
to decodetree.
Backports commit e3d6f4290c788e850c64815f0b3e331600a4bcc0 from qemu
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 sparc_env_get_cpu with env_archcpu. The combination
CPU(sparc_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 5a59fbce9141c40db0f0a5a6e17583ad9189b48b from qemu
Cleanup in the boilerplate that each target must define.
Replace riscv_env_get_cpu with env_archcpu. The combination
CPU(riscv_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 3109cd98a6c0c618189b38a83a8aa29cb20acbce from qemu
Cleanup in the boilerplate that each target must define.
Replace mips_env_get_cpu with env_archcpu. The combination
CPU(mips_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 5a7330b35cabc9e2fd3a8577b7004b63af8c57f3 from qemu
Cleanup in the boilerplate that each target must define.
The combination CPU(m68k_env_get_cpu) should have used
ENV_GET_CPU to begin; use env_cpu now.
Backports commit a8d92fd869c601f723b82d9736a2d78ae640b8a2 from qemu
Cleanup in the boilerplate that each target must define.
Replace x86_env_get_cpu with env_archcpu. The combination
CPU(x86_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 6aa9e42f27331be34e06d4d66f92f2272868f96a 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
Outline places for future MSA helpers to follow the same organization
as in MSA tests.
Backports commit 7471df9f9eaca7c4495d77265864d56644a08b23 from qemu
The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR
IA32_MISC_ENABLE MWAIT bit and as userspace has control of them
both, it is userspace's job to configure both bits to match on
the initial setup.
Backports commit 4cfd7bab3f5564f6c1a23b06f73d5aa2f957cd16 from qemu
Add emulation of MMI instruction PCPYUD. The emulation is implemented
using TCG front end operations directly to achieve better performance.
Backports commit fd487f83ea92d790559813c5a0a719c30ca9ecde from qemu
Add emulation of MMI instruction PCPYLD. The emulation is implemented
using TCG front end operations directly to achieve better performance.
Backports commit b87eef31f2f8047077d79c3180e9c8e762d2a50f from qemu
Add emulation of MMI instruction PCPYH. The emulation is implemented
using TCG front end operations directly to achieve better performance.
Backports commit d3434d9f785ddaf40e0fd521ded400643ac4be09 from qemu
Realign comments to fix warnings issued by checkpatc.pl tool
"WARNING: Block comments use a leading /* on a separate line"
within "target/mips/cpu.h" file.
Backports commit 9e72f33d854b0a817c0d2fe4bca693b76f0fe776 from qemu
Add or remove space to fix errors issued by checkpatch.pl tool
"ERROR: spaces required around that..."
"ERROR: space required after that..."
"ERROR: space required before the open parenthesis"
"ERROR: space required after that..."
"ERROR: space prohibited between function name and open parenthesis"
"ERROR: code indent should never use tabs"
"ERROR: line over 90 characters"
within "target/mips/cpu.h" file.
Backports commit 8ebf2e1a68408068c0bcd0d02a783fd12f6a9cb5 from qemu
This commit addresses QEMU Bug #1825311:
mips_cpu_handle_mmu_fault renders all accessed pages executable
It allows finer-grained control over whether the accessed page should
be executable by moving the decision to the underlying map_address
function, which has more information for this.
As a result, pages that have the XI bit set in the TLB and are accessed
for read/write, don't suddenly end up being executable.
Fixes: https://bugs.launchpad.net/qemu/+bug/1825311
Fixes: 2fb58b73746e ('target-mips: add RI and XI fields to TLB entry')
Backports commit 7353113fa482e697a77575086a41f429a01f8dc0 from qemu
The old version of the helper for the INSERT.<B|H|W|D> MSA instructions
has been replaced with four helpers that don't use switch, and change
the endianness of the given index, when executed on a big endian host.
Backports commit c1c9a10fb1f7a6782711817c167a2c20b000fc12 from qemu
The old version of the helper for the COPY_U.<B|H|W> MSA instructions
has been replaced with four helpers that don't use switch, and change
the endianness of the given index, when executed on a big endian host.
Backports commit 41d288582782cf8d63241ecb6efa1e4160fe78f7 from qemu
The old version of the helper for the COPY_S.<B|H|W|D> MSA instructions
has been replaced with four helpers that don't use switch, and change
the endianness of the given index, when executed on a big endian host.
Backports commit 631c467461496dcf6d6a3e4c3d27a1433e96868e from qemu
Fix the case when the host is a big endian machine, and change
the approach toward ST.<B|H|W|D> instruction helpers.
Backports commit 6decc572dcedbf298ae30f8213b39c8b842a595a from qemu
Fix the case when the host is a big endian machine, and change
the approach toward LD.<B|H|W|D> instruction helpers.
Backports commit 83be6b54123a8f3c529554139f1d1e43356edf8d from qemu
MSA instructions MOD_<U|S>.<B|H|W|D> when dividing by zero,
didn't return the same value when executed on a referent hardware
(FPGA MIPS 64 r6, little endian) and when executed on QEMU, which
is not a real bug, because the result when dividing by zero is
UNPREDICTABLE [1] (page 255, 256).
[1] MIPS Architecture for Programmers
Volume IV-j: The MIPS64 SIMD
Architecture Module, Revision 1.12
Backports commit cf122bf8d2732d5d8647901ebaea596668aaaa3a from qemu
MSA instructions DIV_<U|S>.<B|H|W|D> when dividing by zero,
didn't return the same value when executed on a referent hardware
(FPGA MIPS 64 r6, little endian) and when executed on QEMU, which
is not a real bug, because the result when dividing by zero is
UNPREDICTABLE [1] (page 141, 142).
[1] MIPS Architecture for Programmers
Volume IV-j: The MIPS64 SIMD
Architecture Module, Revision 1.12
Backports commit d2a40a5f6938f30f44b536e997e1e89bb62b971c from qemu
According to the spec, "All bits besides SSIP, USIP, and UEIP in the sip
register are read-only." Further, if an interrupt is not delegated to mode x,
then "the corresponding bits in xip [...] should appear to be hardwired to
zero. This patch implements both of those requirements.
Backports commit 087b051a51a0c2a5bc1e8d435a484a8896b4176b from qemu
C.ADDI16SP, C.LWSP, C.JR, C.ADDIW, C.LDSP all have reserved
operands that were not diagnosed.
Backports commit 4cc16b3b9282e04fab8e84d136540757e82af019 from qemu
At the same time deprecate the ISA string CPUs.
It is dobtful anyone specifies the CPUs, but we are keeping them for the
Spike machine (which is about to be depreated) so we may as well just
mark them as deprecated.
Backports commit 8903bf6e6d73d03b988b4a8197132de2ad681ff5 from qemu
The tcg_gen_fooi_tl functions have some immediate constant
folding built in, which match up with some of the riscv asm
builtin macros, like mv and not.
Backports commit 598aa1160c3d17ab9271daf1f69d093ebada3f25 from qemu
This eliminates all functions in insn_trans/trans_rvc.inc.c,
so the entire file can be removed.
Backports commit 0e68e240a9bd3b44a91cd6012f0e2bf2a43b9fe2 from qemu
This eliminates about half of the complicated decode
bits within insn_trans/trans_rvc.inc.c.
Backports commit c2cfb97c01a3636867c1a4a24f8a99fd8c6bed28 from qemu
Special handling for IMM==0 is the only difference between
RVC shifti and RVI shifti. This can be handled with !function.
Backports commit 6cafec92f1c862a9754ef6a28be68ba7178a284d from qemu
In some cases this allows us to directly use the insn32
translator function. In some cases we still need a shim.
Backports commit e1d455dd91c935c714412dafeb24db947429a929 from qemu
The generated functions are only used within translate.c
and do not need to be global, or declared.
Backports commit 81770255581bd210c57b86a6e808628ab8d0c543 from qemu
This patch introduces wrappers around the tcg_gen_exit_tb() and
tcg_gen_lookup_and_goto_ptr() functions that handle single stepping,
i.e. call gen_exception_debug() when single stepping is enabled.
Theses functions are then used instead of the originals, bringing single
stepping handling in places where it was previously ignored such as jalr
and system branch instructions (ecall, mret, sret, etc.).
Backports commit 6e2716d8ca4edf3597307accef7af36e8ad966eb from qemu
The 'sfence.vma' instruction is privileged, and should only ever be allowed
when executing in supervisor mode or higher.
Backports commit b86f4167630802128d94f3c89043d97d2f4c2546 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
We now have an interface for guest visible random numbers.
Backports commit 369fd5ca66810b2ddb16e23a497eabe59385eceb from qemu with
the actual RNG portion disabled for the time being.
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).
Microarchitectural Data Sampling is a hardware vulnerability which allows
unprivileged speculative access to data which is available in various CPU
internal buffers.
Some Intel processors use the ARCH_CAP_MDS_NO bit in the
IA32_ARCH_CAPABILITIES
MSR to report that they are not vulnerable, make it available to
guests.
Backports commit 20140a82c67467f53814ca197403d5e1b561a5e5 from qemu
md-clear is a new CPUID bit which is set when microcode provides the
mechanism to invoke a flush of various exploitable CPU buffers by invoking
the VERW instruction.
Backports commit b2ae52101fca7f9547ac2f388085dbc58f8fe1c0 from qemu
Optimize rotate_x() using tcg_gen_extract_i32(). We can now free the
'sz' tcg_temp earlier. Since it is allocated with tcg_const_i32(),
free it with tcg_temp_free_i32().
Backports commit 60d3d0cfeb1658d2827d6a4f0df27252bb36baba from qemu
The function gen_get_ccr() returns a tcg_temp created with
tcg_temp_new(). Free it with tcg_temp_free().
Backports commit 44c64e90950adf9efe7f4235a32eb868d1290ebb from qemu
Switch the m68k target from the old unassigned_access hook
to the transaction_failed hook.
The notable difference is that rather than it being called
for all physical memory accesses which fail (including
those made by DMA devices or by the gdbstub), it is only
called for those made by the CPU via its MMU. (In previous
commits we put in explicit checks for the direct physical
loads made by the target/m68k code which will no longer
be handled by calling the unassigned_access hook.)
Backports commit e1aaf3a88e95ab007445281e2b2f6e3c8da47f22 from qemu
In get_physical_address(), use address_space_ldl() and
address_space_stl() instead of ldl_phys() and stl_phys().
This allows us to check whether the memory access failed.
For the moment, we simply return -1 in this case;
add a TODO comment that we should ideally generate the
appropriate kind of fault.
Backports commit adcf0bf017351776510121e47b9226095836023c from qemu
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
Note that env->pc is removed from the qemu_log as that value is garbage.
The PC isn't recovered until cpu_restore_state, called from
cpu_loop_exit_restore, called from riscv_raise_exception.
Backports commit 8a4ca3c10a96be6ed7f023b685b688c4d409bbcb from qemu
Note that env->active_tc.PC is removed from the qemu_log as that value
is garbage. The PC isn't recovered until cpu_restore_state, called from
cpu_loop_exit_restore, called from do_raise_exception_err.
Backports commit 931d019f5b2e7bbacb162869497123be402ddd86 from qemu
Since the only non-negative TLBRET_* value is TLBRET_MATCH,
the subsequent test for ret < 0 is useless. Use early return
to allow subsequent blocks to be unindented.
Backports commit e38f4eb63020075432cb77bf48398187809cf4a3 from qemu
At present we give ret = 0, or TLBRET_MATCH. This gets matched
by the default case, which falls through to TLBRET_BADADDR.
However, it makes more sense to use a proper value. All of the
tlb-related exceptions are handled identically in cpu_loop.c,
so TLBRET_BADADDR is as good as any other. Retain it.
Backports commit 995ffde9622c01f5b307cab47f9bd7962ac09db2 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
Leading underscores are ill-advised because such identifiers are
reserved. Trailing underscores are merely ugly. Strip both.
Our header guards commonly end in _H. Normalize the exceptions.
Done with scripts/clean-header-guards.pl.
Backports commit a8b991b52dcde75ab5065046653626951aac666d 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 87d757d60d66d5ee1608460b0f1e07e2b758db9c from qemu
Thereby decoupling the resulting translated code from the current state
of the system.
Backports commit f0ddf11b23260f0af84fb529486a8f9ba2d19401 from qemu
Thereby decoupling the resulting translated code from the current state
of the system.
Backports commit b5e3b4c2aca8eb5a9cfeedfb273af623f17c3731 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
Add a new base CPU model called 'Dhyana' to model processors from Hygon
Dhyana(family 18h), which derived from AMD EPYC(family 17h).
The following features bits have been removed compare to AMD EPYC:
aes, pclmulqdq, sha_ni
The Hygon Dhyana support to KVM in Linux is already accepted upstream[1].
So add Hygon Dhyana support to Qemu is necessary to create Hygon's own
CPU model.
Reference:
[1] https://git.kernel.org/tip/fec98069fb72fb656304a3e52265e0c2fc9adf87
Backports commit 8d031cec366f26669807eb43f61eb335973b7053 from qemu
Use inline functions rather than macros for cpu_ld/st accessors
for the *-user configurations, as we already do for softmmu.
This has a two advantages:
* we can actually typecheck our arguments
* we don't need to leak the _raw macros everywhere
Since the _kernel functions were only used by target-i386/seg_helper.c,
put the definitions for them in that file too. (It already has the
similar template include code to define them for the softmmu case,
so it makes sense to have it deal with defining them for user-only.)
Backports commit 9220fe54c679d145232a28df6255e166ebf91bab 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.
Fix a TCG crash due to attempting an atomic increment
operation without having set up the address first.
This is a similar case to that dealt with in commit
e84fcd7f662a0d8198703, and we fix it in the same way.
Fixes: https://bugs.launchpad.net/qemu/+bug/1807675
Backports commit 8cb2ca3d7479748587313f0b34034a3f8aa08c92 from qemu
While running the GCC test suite against 4.0.0-rc0, Kito found a
regression introduced by the decodetree conversion that caused divuw and
remuw to sign-extend their inputs. The ISA manual says they are
supposed to be zero extended:
DIVW and DIVUW instructions are only valid for RV64, and divide the
lower 32 bits of rs1 by the lower 32 bits of rs2, treating them as
signed and unsigned integers respectively, placing the 32-bit
quotient in rd, sign-extended to 64 bits. REMW and REMUW
instructions are only valid for RV64, and provide the corresponding
signed and unsigned remainder operations respectively. Both REMW
and REMUW always sign-extend the 32-bit result to 64 bits, including
on a divide by zero.
Here's Kito's reduced test case from the GCC test suite
unsigned calc_mp(unsigned mod)
{
unsigned a,b,c;
c=-1;
a=c/mod;
b=0-a*mod;
if (b > mod) { a += 1; b-=mod; }
return b;
}
int main(int argc, char *argv[])
{
unsigned x = 1234;
unsigned y = calc_mp(x);
if ((sizeof (y) == 4 && y != 680)
|| (sizeof (y) == 2 && y != 134))
abort ();
exit (0);
}
I haven't done any other testing on this, but it does fix the test case.
Backports commit f17e02cd3731bdfe2942d1d0b2a92f26da02408c from qemu
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
