Most of them use guard symbols like CPU_$target_H, but we also have
__MIPS_CPU_H__ and __TRICORE_CPU_H__. They all upset
scripts/clean-header-guards.pl.
The script dislikes CPU_$target_H because they don't match their file
name (they should, to make guard collisions less likely). The others
are reserved identifiers.
Clean them all up: use guard symbol $target_CPU_H for
target-$target/cpu.h.
Backports commit 07f5a258750b3b9a6e10fd5ec3e29c9a943b650e from qemu
There are functions tlb_fill(), cpu_unaligned_access() and
do_unaligned_access() that are called with access type and mmu index
arguments. But these arguments are named 'is_write' and 'is_user' in their
declarations. The patches fix the arguments to avoid a confusion.
Backports commit b35399bb4e9968296a12303b00f9f2066470e987 from qemu
ASID currently has uint8_t type which is too small since some processors
support more than 8 bits ASID. Therefore change its type to uint16_t.
Backports commit 2d72e7b047d800c9f99262466f65a98684ecca14 from qemu
Replace hardcoded 0xbfc00000 with exception_base which is initialized with
this default address so there is no functional change here.
However, it is now exposed and consequently it will be possible to modify
it from outside of the CPU.
Backports commit 89777fd10fc3dd573c3b4d1b2efdd10af823c001 from qemu
Add preprocessor definition of FCR31's FS bit, and update related
code for setting this bit.
Backports commit 77be419980114d75605811e1681115d0919cfa1a from qemu
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.
Backports commit 599bc5e89c46f95f86ccad0d747d041c89a28806 from qemu
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.
Backports commit af39bc8c49224771ec0d38f1b693ea78e221d7bc from qemu
exec-all.h contains TCG-specific definitions. It is not needed outside
TCG-specific files such as translate.c, exec.c or *helper.c.
One generic function had snuck into include/exec/exec-all.h; move it to
include/qom/cpu.h.
Backports commit 63c915526d6a54a95919ebece83fa9ca631b2508 from qemu
These are here for historical reasons: they are needed from both gdbstub.c
and op_helper.c, and the latter was compiled with fixed AREG0. It is
not needed anymore, so uninline them.
Backports commit e6623d88f44aae9e9c78276c0cb7bd352283d50a from qemu
Make MIPSCPU an opaque type within cpu-qom.h, and move all definitions of
private methods, as well as all type definitions that require knowledge
of the layout to cpu.h. This helps making files independent of NEED_CPU_H
if they only need to pass around CPU pointers.
Backports commit 416bf936864f16caad6993b9ebd452fb34f801bd from qemu
We are inconsistent with the type of tb->flags: usage varies loosely
between int and uint64_t. Settle to uint32_t everywhere, which is
superior to both: at least one target (aarch64) uses the most significant
bit in the u32, and uint64_t is wasteful.
Compile-tested for all targets.
Backports commit 89fee74a0f066dfd73830a7b5fa137e87888c870 from qemu
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.
Backports commit ba5c79f26221c0fd7139c883a34a4e75d993f732 from qemu
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.
Backports commit f6d4dd810983fdf3d1c9fb81838167efef63d1c8 from qemu
Physical base address for the memory-mapped Coherency Manager Global
Configuration Register space.
The MIPS default location for the GCR_BASE address is 0x1FBF_8.
This register only exists if Config3 CMGCR is set to one.
Backports commit c870e3f52cac0c8a4a1377398327c4ff20d49d41 from qemu
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.
Backports commit 01bc435b44b8802cc4697faa07d908684afbce4e from qemu
The r4k_tlb_t structure uses the uint_fast*_t types. Most of these
uses are in bitfields and are thus pointless, because the bitfield
itself specifies the width of the type; just use 'unsigned int'
instead. (On glibc uint_fast16_t is defined as either 32 or 64 bits,
so we know the code is not reliant on it being exactly 16 bits.)
There is also one use of uint_fast8_t, which we replace with uint8_t,
because both are exactly 8 bits on glibc and this is the only
place outside the softfloat code which uses an int_fast*_t type.
Backports commit d783f78933b212537ece77c7ec66866cc2bc0f4d from qemu
The TARGET_HAS_ICE #define is intended to indicate whether a target-*
guest CPU implementation supports the breakpoint handling. However,
all our guest CPUs have that support (the only two which do not
define TARGET_HAS_ICE are unicore32 and openrisc, and in both those
cases the bp support is present and the lack of the #define is just
a bug). So remove the #define entirely: all new guest CPU support
should include breakpoint handling as part of the basic implementation.
Backports commit ec53b45bcd1f74f7a4c31331fa6d50b402cd6d26 from qemu
CP0.Status.KX/SX/UX bits are responsible for enabling access to 64-bit
Kernel/Supervisor/User Segments. If bit is cleared an access to
corresponding segment should generate Address Error Exception.
However, the guest may still be able to access some pages belonging to
the disabled 64-bit segment because we forget to flush QEMU TLB.
This patch fixes it.
Backports commit f93c3a8d0c0c1038dbe1e957eb8ab92671137975 from qemu
Add Performance Counter (4) and XNP (5) register numbers to RDHWR.
Add check_hwrena() to simplify access control checkings.
Add RDHWR support to microMIPS R6.
Backports commit b00c72180c36510bf9b124e190bd520e3b7e1358 from qemu
Implement the relationship between CP0.Status.KX, SX and UX. It should not
be possible to set UX bit if SX is 0, the same applies for setting SX if
KX is 0.
Backports commit 2dcf7908d9e0274c08911400beb7ed14276bb170 from qemu
The only generic code relying on this is linux-user, but linux users'
default behaviour of defaulting ELF_MACHINE to ELF_ARCH will handle
this.
The bootloaders can just pass EM_MIPS directly, as that is
architecture specific code.
This removes another architecture specific definition from the global
namespace.
Backports commit 04ce380e9e3fad1dbf4e86ebdf9315573a06b30e from qemu
This patch improves exception handling in MIPS.
Instructions generate several types of exceptions.
When exception is generated, it breaks the execution of the current
translation block. Implementation of the exceptions handling does not
correctly restore icount for the instruction which caused the exception.
In most cases icount will be decreased by the value equal to the size of
TB. This patch passes pointer to the translation block internals to the
exception handler. It allows correct restoring of the icount value.
Backports commit 9c708c7f9fbb813a3fac02f2728e51e62f2f5ffc from qemu
This is set to true when the index is for an instruction fetch
translation.
The core get_page_addr_code() sets it, as do the SOFTMMU_CODE_ACCESS
acessors.
All targets ignore it for now, and all other callers pass "false".
This will allow targets who wish to split the mmu index between
instruction and data accesses to do so. A subsequent patch will
do just that for PowerPC.
Backports commit 97ed5ccdee95f0b98bedc601ff979e368583472c from qemu
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
Backports commit aff2bc6dc6d839caf6df0900437cc2cc9e180605 from qemu
Remove un-needed usages of ENV_GET_CPU() by converting the APIs to use
CPUState pointers and retrieving the env_ptr as minimally needed.
Scripted conversion for target-* change:
for I in target-*/cpu.h; do
sed -i \
's/\(^int cpu_[^_]*_exec(\)[^ ][^ ]* \*s);$/\1CPUState *cpu);/' \
$I;
done
Backports commit ea3e9847408131abc840240bd61e892d28459452 from qemu
Implement MTHC0 and MFHC0 instructions. In MIPS32 they are used to access
upper word of extended to 64-bits CP0 registers.
In MIPS64, when CP0 destination register specified is the EntryLo0 or
EntryLo1, bits 1:0 of the GPR appear at bits 31:30 of EntryLo0 or
EntryLo1. This is to compensate for RI and XI, which were shifted to bits
63:62 by MTC0 to EntryLo0 or EntryLo1. Therefore creating separate
functions for EntryLo0 and EntryLo1.
Backports commit 5204ea79ea739b557f47fc4db96c94edcb33a5d6 from qemu
CP0.PageGrain.ELPA enables support for large physical addresses. This field
is encoded as follows:
0: Large physical address support is disabled.
1: Large physical address support is enabled.
If this bit is a 1, the following changes occur to coprocessor 0 registers:
- The PFNX field of the EntryLo0 and EntryLo1 registers is writable and
concatenated with the PFN field to form the full page frame number.
- Access to optional COP0 registers with PA extension, LLAddr, TagLo is
defined.
P5600 can operate in 32-bit or 40-bit Physical Address Mode. Therefore if
XPA is disabled (CP0.PageGrain.ELPA = 0) then assume 32-bit Address Mode.
In MIPS64 assume 36 as default PABITS (when CP0.PageGrain.ELPA = 0).
env->PABITS value is constant and indicates maximum PABITS available on
a core, whereas env->PAMask is calculated from env->PABITS and is also
affected by CP0.PageGrain.ELPA.
Backports commit e117f52636d04502fab28bd3abe93347c29f39a5 from qemu
Extend EntryLo0, EntryLo1, LLAddr and TagLo from 32 to 64 bits in MIPS32.
Introduce gen_move_low32() function which moves low 32 bits from 64-bit
temp to GPR; it sign extends 32-bit value on MIPS64 and truncates on
MIPS32.
Backports commit 284b731a6ae47b9ebabb9613e753c4d83cf75dd3 from qemu
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.
Backports commit ce9782f40ac16660ea9437bfaa2c9c34d5ed8110 from qemu
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.
Backports commit 7c979afd11b09a16634699dd6344e3ba10c9677e from qemu
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.
Backports commit 644511117e7ca9f26d633a59c202a297113a796c from qemu
Add missing calls to synchronise the SoftFloat status with the CP1.FSCR:
+ for the rounding and flush-to-zero modes upon processor reset,
+ for the flush-to-zero mode on FSCR updates through the GDB stub.
Refactor code accordingly and remove the redundant RESTORE_ROUNDING_MODE
macro.
Backports commit bb962386b82c1b0e9e12fdb6b9bb62106bf1f822 from qemu
Make sure the address space is unconditionally wrapped on 32-bit
processors, that is ones that do not implement at least the MIPS III
ISA.
Also make MIPS16 SAVE and RESTORE instructions use address calculation
rather than plain arithmetic operations for stack pointer manipulation
so that their semantics for stack accesses follows the architecture
specification. That in particular applies to user software run on
64-bit processors with the CP0.Status.UX bit clear where the address
space is wrapped to 32 bits.
Backports commit c48245f0c62405f27266fcf08722d8c290520418 from qemu
Tighten ISA level checks down to MIPS II that many of our instructions
are missing. Also make sure any 64-bit instruction enables are only
applied to 64-bit processors, that is ones that implement at least the
MIPS III ISA.
Backports commit d9224450208e0de62323b64ace91f98bc31d6e2c from qemu
Make writes to CP0.Status and CP0.Cause have the same effect as
executing corresponding MTC0 instructions would in Kernel Mode. Also
ignore writes in the user emulation mode.
Currently for requests from the GDB stub we write all the bits across
both registers, ignoring any read-only locations, and do not synchronise
the environment to evaluate side effects. We also write these registers
in the user emulation mode even though a real kernel presents them as
read only.
Backports commit 81a423e6c6d3ccaa79de4e58024369c660c1eeb4 from qemu
Make the data type used for the CP0.Config4 and CP0.Config5 registers
and their mask signed, for consistency with the remaining 32-bit CP0
registers, like CP0.Config0, etc.
Backports commit 8280b12c0e4b515d707509dde4ddde05d9bda4ef from qemu
