MIPS64R6-generic gradually gets closer to I6400 CPU, feature-wise. Rename
it to make it clear which MIPS processor it is supposed to emulate.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
This patch implements read and write access rules for Mips floating
point control and status register (FCR31). The change can be divided
into following parts:
- Add fields that will keep FCR31's R/W bitmask in procesor
definitions and processor float_status structure.
- Add appropriate value for FCR31's R/W bitmask for each supported
processor.
- Add function for setting snan_bit_is_one, and integrate it in
appropriate places.
- Modify handling of CTC1 (case 31) instruction to use FCR31's R/W
bitmask.
- Modify handling user mode executables for Mips, in relation to the
bit EF_MIPS_NAN2008 from ELF header, that is in turn related to
reading and writing to FCR31.
- Modify gdb behavior in relation to FCR31.
Signed-off-by: Thomas Schwinge <thomas@codesourcery.com>
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Function msa_reset() is updated so that flag snan_bit_is_one is
properly set to 0.
By applying this patch, a number of incorrect MSA behaviors that
require IEEE 754-2008 compliance will be fixed. Those are behaviors
that (up to the moment of applying this patch) did not get the desired
functionality from SoftFloat library with respect to distinguishing
between quiet and signaling NaN, getting default NaN values (both
quiet and signaling), establishing if a floating point number is NaN
or not, etc.
Two examples:
* FMAX, FMIN will now correctly detect and propagate NaNs.
* FCLASS.D ans FCLASS.S will now correcty detect NaN flavors.
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
This patch modifies SoftFloat library so that it can be configured in
run-time in relation to the meaning of signaling NaN bit, while, at the
same time, strictly preserving its behavior on all existing platforms.
Background:
In floating-point calculations, there is a need for denoting undefined or
unrepresentable values. This is achieved by defining certain floating-point
numerical values to be NaNs (which stands for "not a number"). For additional
reasons, virtually all modern floating-point unit implementations use two
kinds of NaNs: quiet and signaling. The binary representations of these two
kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally,
the first bit of mantissa).
Up to 2008, standards for floating-point did not specify all details about
binary representation of NaNs. More specifically, the meaning of the bit
that is used for distinguishing between signaling and quiet NaNs was not
strictly prescribed. (IEEE 754-2008 was the first floating-point standard
that defined that meaning clearly, see [1], p. 35) As a result, different
platforms took different approaches, and that presented considerable
challenge for multi-platform emulators like QEMU.
Mips platform represents the most complex case among QEMU-supported
platforms regarding signaling NaN bit. Up to the Release 6 of Mips
architecture, "1" in signaling NaN bit denoted signaling NaN, which is
opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture
adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of
that, Mips architecture for SIMD (also known as MSA, or vector instructions)
also specifies signaling bit in accordance to IEEE standard. MSA unit can be
implemented with both pre-Release 6 and Release 6 main processor units.
QEMU uses SoftFloat library to implement various floating-point-related
instructions on all platforms. The current QEMU implementation allows for
defining meaning of signaling NaN bit during build time, and is implemented
via preprocessor macro called SNAN_BIT_IS_ONE.
On the other hand, the change in this patch enables SoftFloat library to be
configured in run-time. This configuration is meant to occur during CPU
initialization, at the moment when it is definitely known what desired
behavior for particular CPU (or any additional FPUs) is.
The change is implemented so that it is consistent with existing
implementation of similar cases. This means that structure float_status is
used for passing the information about desired signaling NaN bit on each
invocation of SoftFloat functions. The additional field in float_status is
called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE.
IMPORTANT:
This change is not meant to create any change in emulator behavior or
functionality on any platform. It just provides the means for SoftFloat
library to be used in a more flexible way - in other words, it will just
prepare SoftFloat library for usage related to Mips platform and its
specifics regarding signaling bit meaning, which is done in some of
subsequent patches from this series.
Further break down of changes:
1) Added field snan_bit_is_one to the structure float_status, and
correspondent setter function set_snan_bit_is_one().
2) Constants <float16|float32|float64|floatx80|float128>_default_nan
(used both internally and externally) converted to functions
<float16|float32|float64|floatx80|float128>_default_nan(float_status*).
This is necessary since they are dependent on signaling bit meaning.
At the same time, for the sake of code cleanup and simplicity, constants
<floatx80|float128>_default_nan_<low|high> (used only internally within
SoftFloat library) are removed, as not needed.
3) Added a float_status* argument to SoftFloat library functions
XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_),
XXX_maybe_silence_nan(XXX a_). This argument must be present in
order to enable correct invocation of new version of functions
XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128>
here)
4) Updated code for all platforms to reflect changes in SoftFloat library.
This change is twofolds: it includes modifications of SoftFloat library
functions invocations, and an addition of invocation of function
set_snan_bit_is_one() during CPU initialization, with arguments that
are appropriate for each particular platform. It was established that
all platforms zero their main CPU data structures, so snan_bit_is_one(0)
in appropriate places is not added, as it is not needed.
[1] "IEEE Standard for Floating-Point Arithmetic",
IEEE Computer Society, August 29, 2008.
Signed-off-by: Thomas Schwinge <thomas@codesourcery.com>
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Tested-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[leon.alrae@imgtec.com:
* cherry-picked 2 chunks from patch #2 to fix compilation warnings]
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
The MAAR register is a read/write register included in Release 5
of the architecture that defines the accessibility attributes of
physical address regions. In particular, MAAR defines whether an
instruction fetch or data load can speculatively access a memory
region within the physical address bounds specified by MAAR.
As QEMU doesn't do speculative access, hence this patch only
provides ability to access the registers.
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Indicate that in the MIPS64R6-generic CPU the memory-mapped
Global Configuration Register Space is implemented.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
MIPS Release 6 and MIPS SIMD Architecture make it mandatory to have IEEE
754-2008 FPU which is indicated by CP1 FIR.HAS2008, FCSR.ABS2008 and
FCSR.NAN2008 bits set to 1.
In QEMU we still keep these bits cleared as there is no 2008-NaN support.
However, this now causes problems preventing from running R6 Linux with
the v4.5 kernel. Kernel refuses to execute 2008-NaN ELFs on a CPU
whose FPU does not support 2008-NaN encoding:
(...)
VFS: Mounted root (ext4 filesystem) readonly on device 8:0.
devtmpfs: mounted
Freeing unused kernel memory: 256K (ffffffff806f0000 - ffffffff80730000)
request_module: runaway loop modprobe binfmt-464c
Starting init: /sbin/init exists but couldn't execute it (error -8)
request_module: runaway loop modprobe binfmt-464c
Starting init: /bin/sh exists but couldn't execute it (error -8)
Kernel panic - not syncing: No working init found. Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
Therefore always indicate presence of 2008-NaN support in R6 as well as in
R5+MSA CPUs, even though this feature is not yet supported by MIPS in QEMU.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
MIPS Release 6 provides multi-threading features which replace
pre-R6 MT Module. CP0.Config3.MT is always 0 in R6, instead there is new
CP0.Config5.VP (Virtual Processor) bit which indicates presence of
multi-threading support which includes CP0.GlobalNumber register and
DVP/EVP instructions.
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Set Config5.XNP for R6 cores to indicate the extended LL/SC family
of instructions NOT present.
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
As full specification of P5600 is available, mips32r5-generic should
be renamed to P5600 and corrected as its intention.
Correct PRid and detail of configuration.
Features which are not currently supported are described as FIXME.
Fix Config.MM bit location
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
[leon.alrae@imgtec.com: correct cache line sizes and LLAddr shift]
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Fix core configuration for MIPS64R6-generic to make it as close as
I6400.
I6400 core has 48-bit of Virtual Address available (SEGBITS).
MIPS SIMD Architecture is available.
Rearrange order of bits to match the specification.
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Define a new CPU definition supporting MIPS32 Release 6 ISA and
microMIPS32 Release 6 ISA.
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Enable XPA in MIPS32R5-generic and LPA in MIPS64R6-generic.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
PABITS are not hardcoded to 36 bits and we do not model 59 PABITS (which is
the architectural limit) in QEMU.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
ERETNC is identical to ERET except that an ERETNC will not clear the LLbit
that is set by execution of an LL instruction, and thus when placed between
an LL and SC sequence, will never cause the SC to fail.
Presence of ERETNC is denoted by the Config5.LLB.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Release 6 requires misaligned memory access support for all ordinary memory
access instructions (for example, LW/SW, LWC1/SWC1).
However misaligned support is not provided for certain special memory accesses
such as atomics (for example, LL/SC).
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
This relatively small architectural feature adds the following:
FIR.FREP: Read-only. If FREP=1, then Config5.FRE and Config5.UFE are
available.
Config5.FRE: When enabled all single-precision FP arithmetic instructions,
LWC1/LWXC1/MTC1, SWC1/SWXC1/MFC1 cause a Reserved Instructions
exception.
Config5.UFE: Allows user to write/read Config5.FRE using CTC1/CFC1
instructions.
Enable the feature in MIPS64R6-generic CPU.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Save MSACSR state. Also remove fp_status, msa_fp_status, hflags and restore
them in post_load() from the architectural registers.
Float exception flags are not present in vmstate. Information they carry
is used only by softfloat caller who translates them into MIPS FCSR.Cause,
FCSR.Flags and then they are cleared. Therefore there is no need for saving
them in vmstate.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Enable vectored interrupt support for the 74Kf CPU, reflecting hardware.
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Add the M14K and M14Kc processors from MIPS Technologies that are the
original implementation of the microMIPS ISA. They are dual instruction
set processors, implementing both the microMIPS and the standard MIPSr32
ISA.
These processors correspond to the M4K and 4KEc CPUs respectively,
except with support for the microMIPS instruction set added, support for
the MCU ASE added and two extra interrupt lines, making a total of 8
hardware interrupts plus 2 software interrupts. The remaining parts of
the microarchitecture, in particular the pipeline, stayed unchanged.
The presence of the microMIPS ASE is is reflected in the configuration
added. We currently have no support for the MCU ASE, including in
particular the ACLR, ASET and IRET instructions in either encoding, and
we have no support for the extra interrupt lines, including bits in
CP0.Status and CP0.Cause registers, so these features are not marked,
making our support diverge from real hardware.
Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Add the 5KEc and 5KEf processors from MIPS Technologies that are the
original implementation of the MIPS64r2 ISA.
Silicon for these processors has never been taped out and no soft cores
were released even. They do exist though, a CP0.PRId value has been
assigned and experimental RTLs produced at the time the MIPS64r2 ISA has
been finalized. The settings introduced here faithfully reproduce that
hardware.
As far the implementation goes these processors are the same as the 5Kc
and the 5Kf CPUs respectively, except implementing the MIPS64r2 rather
than the original MIPS64 instruction set. There must have been some
updates to the CP0 architecture as mandated by the ISA, such as the
addition of the EBase register, although I am not sure about the exact
details, no documentation has ever been produced for these processors.
The remaining parts of the microarchitecture, in particular the
pipeline, stayed unchanged. Or to put it another way, the difference
between a 5K and a 5KE CPU corresponds to one between a 4K and a 4KE
CPU, except for the 64-bit rather than 32-bit ISA.
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Set the CP0.Config3.DSP2P bit for the 74kf processor and both that bit
and the CP0.Config3.DSP bit for the artificial mips32r5-generic and
mips64dspr2 processors. They have the DSPr2 ASE enabled in `insn_flags'
and CPUs that implement that ASE need to have both CP0.Config3.DSP and
CP0.Config3.DSP2P set or software won't detect its presence.
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
[leon.alrae@imgtec.com: remove DSP flags from mips32r5-generic]
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
add MSA support to mips32r5-generic core definition
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
add msa_reset() and global msa register (d type only)
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
For Standard TLB configuration (Config.MT=1):
TLBINV invalidates a set of TLB entries based on ASID. The virtual address is
ignored in the entry match. TLB entries which have their G bit set to 1 are not
modified.
TLBINVF causes all entries to be invalidated.
Single TLB entry can be marked as invalid on TLB entry write by having
EntryHi.EHINV set to 1.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
PageGrain needs rw bitmask which differs between MIPS architectures.
In pre-R6 if RIXI is supported, PageGrain.XIE and PageGrain.RIE are writeable,
whereas in R6 they are read-only 1.
On MIPS64 mtc0 instruction left shifts bits 31:30 for MIPS32 backward
compatiblity, therefore there are separate mtc0 and dmtc0 helpers.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Add U suffix to various places where we shift a 1 left by 31,
to avoid undefined behaviour.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Description of UFR feature:
Required in MIPS32r5 if floating point is implemented and user-mode FR
switching is supported. The UFR register allows user-mode to clear StatusFR
by executing a CTC1 to UFR with GPR[0] as input, and read StatusFR by
executing a CFC1 to UFR.
helper_ctc1 has been extended with an additional parameter rt to check
requirements for UFR feature.
Definition of mips32r5-generic has been modified to include support for UFR.
Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
Reviewed-by: Eric Johnson <eric.johnson@imgtec.com>
Add CP0_Config5, define rw_bitmask and enable modifications.
Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
Reviewed-by: Eric Johnson <eric.johnson@imgtec.com>
Add mips32r5-generic among CPU definitions for MIPS.
Define ISA_MIPS32R3 and ISA_MIPS32R5.
Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
Reviewed-by: Eric Johnson <eric.johnson@imgtec.com>
34Kf core does support DSP ASE.
CP0_Config3 configuration for 34Kf and description are wrong.
Please refer to MIPS32(R) 34Kf(TM) Processor Core Datasheet
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
fprintf_function uses format checking with GCC_FMT_ATTR.
Format errors were fixed in
* target-i386/helper.c
* target-mips/translate.c
* target-ppc/translate.c
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Fix regression introduced by d19954f46d.
4Kc and 4KEc don't support MIPS16.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
4Kc, 4KEc cores do not support MIPS16, so not only the
CP0_Config1 had to be fixed (see previous patch),
but also MIPS16 instructions must not be executed.
(Hint from Nathan Froyd, thanks).
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Running programs with the MIPS user-mode emulator fails during dynamic
loading, as floating-point instructions are not enabled in in
env->hflags. Move the code for doing so from fpu_init to cpu_reset so
the MIPS_HFLAG_{FPU,F64} setting doesn't get clobbered by cpu_reset
setting env->hflags to MIPS_HFLAG_UM.
The same end can be achieved by swapping the ordering of fpu_init and
cpu_reset in cpu_mips_init, but it seemed better to consolidate the
CONFIG_USER_ONLY code into a single location.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
