The exception return address for nios2 is the instruction
after the one that was executing at the time of the exception.
We have so far implemented this by advancing the pc during the
process of raising the exception. It is perhaps a little less
confusing to do this advance in the translator (and helpers)
when raising the exception in the first place, so that we may
more closely match kernel sources.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-58-richard.henderson@linaro.org>
This is the cpu side of the operation. Register one irq line,
called EIC. Split out the rather different processing to a
separate function.
Delay initialization of gpio irqs until realize. We need to
provide a window after init in which the board can set eic_present.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-57-richard.henderson@linaro.org>
When CRS = 0, we restore from estatus; otherwise from sstatus.
Update for the new CRS.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-56-richard.henderson@linaro.org>
Implement these out of line, so that tcg global temps
(aka the architectural registers) are synced back to
tcg storage as required. This makes sure that we get
the proper results when status.PRS == status.CRS.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-55-richard.henderson@linaro.org>
Do not actually enable them so far, in terms of being able
to change the current register set, but add all of the
plumbing to address them. Do not enable them for user-only.
Add an env->regs pointer that handles the indirection to
the current register set. The naming of the pointer hides
the difference between old and new, user-only and sysemu.
From the notes on wrprs, which states that r0 must be initialized
before use in shadow register sets, infer that R_ZERO is *not*
hardwired to zero in shadow register sets, but that it is still
read-only. Introduce tbflags bit R0_0 to track that it has been
properly set to zero. Adjust load_gpr to reflect this.
At the same time we might as well special case crs == 0 to avoid
the indirection through env->regs during translation as well; this
is intended to be the most common case for non-interrupt handlers.
Init env->regs at reset.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-54-richard.henderson@linaro.org>
Indirect branches, plus eret and bret optionally raise
an exception when branching to a misaligned address.
The exception is required when an mmu is enabled, but
enable it always because the fallback behaviour is not
documented (though presumably it discards low bits).
For the purposes of the linux-user cpu loop, if EXCP_UNALIGN
(misaligned data) were to arrive, it would be treated the
same as EXCP_UNALIGND (misaligned destination). See the
!defined(CONFIG_NIOS2_ALIGNMENT_TRAP) block in kernel/traps.c.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-53-richard.henderson@linaro.org>
Use lookup_and_goto_ptr for indirect chaining between TBs.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-52-richard.henderson@linaro.org>
Depending on the reason for ending the TB, we can chain
to the next TB because the PC is constant.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-51-richard.henderson@linaro.org>
Rather than force all callers to set this, do it
within the subroutine.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-50-richard.henderson@linaro.org>
Split out a function to perform an indirect branch.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-49-richard.henderson@linaro.org>
Unaligned traps are optional, but required with an mmu.
Turn them on always, because the fallback behaviour undefined.
Enable alignment checks in the config file.
Unwind the guest pc properly from do_unaligned_access.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-48-richard.henderson@linaro.org>
There's nothing about EH that affects translation,
so there's no need to include it in tb->flags.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-47-richard.henderson@linaro.org>
Constrain all references to cpu_R[] to load_gpr and dest_gpr.
This will be required for supporting shadow register sets.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-46-richard.henderson@linaro.org>
Do as little work as possible within the macro.
Split out helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Rename the macro from gen_r_mul, because these are the multiply
variants that produce a high-part result. Do as little work as
possible within the macro; split out helper functions and pass
in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split the macro in two, one for reg/imm and one for reg/reg.
Do as little work as possible within the macros; split out
helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do as little work as possible within the macro.
Split out helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do as little work as possible within the macro.
Split out helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Currently the structures are anonymous within the macro.
Pull them out to standalone types.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-44-richard.henderson@linaro.org>
Replace current uses of tcg_const_tl, and remove the frees.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-43-richard.henderson@linaro.org>
Division may (optionally) raise a division exception.
Since the linux kernel has been prepared for this for
some time, enable it by default.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-42-richard.henderson@linaro.org>
This interrupt bit is never set, so testing it in
nios2_cpu_has_work is pointless.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-41-richard.henderson@linaro.org>
Without EIC, this bit is RES1. So set the bit at reset,
and add it to the readonly fields of CR_STATUS.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-40-richard.henderson@linaro.org>
Copy the existing cpu_index into the space reserved for CR_CPUID.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-39-richard.henderson@linaro.org>
Create an array of masks which detail the writable and readonly
bits for each control register. Apply them when writing to
control registers, including the write to status during eret.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-38-richard.henderson@linaro.org>
The 4 lower bits, D, PERM, BAD, DBL, are unconditionally set on any
exception with EH=0, or so says Table 42 (Processor Status After
Taking Exception).
We currently do not set PERM or BAD at all, and only set/clear
DBL for tlb miss, and do not clear DBL for any other exception.
It is a bit confusing to set D in tlb_fill and the rest during
do_interrupt, so move the setting of D to do_interrupt as well.
To do this, split EXP_TLBD into two cases, EXCP_TLB_X and EXCP_TLB_D,
which allows us to distinguish them during do_interrupt. Choose
a value for EXCP_TLB_D such that when truncated it produces the
correct value for exception.CAUSE.
Rename EXCP_TLB[RWX] to EXCP_PERM_[RWX], to emphasize that the
exception is permissions related. Rename EXCP_SUPER[AD] to
EXCP_SUPERA_[DX] to emphasize that they are both "supervisor
address" exceptions, data and execute.
Retain the setting of tlbmisc.WE for the fast-tlb-miss path, as it
is being relied upon, but remove it from the permission path.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-37-richard.henderson@linaro.org>
The register is entirely read-only for software, and we do not
implement ECC, so we need not deposit the cause into an existing
value; just create a new value from scratch.
Furthermore, exception.CAUSE is not written for break exceptions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-36-richard.henderson@linaro.org>
While some of the plumbing for misaligned data is present, in the form
of nios2_cpu_do_unaligned_access, the hook will not be called because
TARGET_ALIGNED_ONLY is not set in configs/targets/nios2-softmmu.mak.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-35-richard.henderson@linaro.org>
Performing this early means that we can merge more cases
within the non-logging switch statement.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-34-richard.henderson@linaro.org>
Split out do_exception and do_iic_irq to handle bulk of the interrupt and
exception processing. Parameterize the changes required to cpu state.
The status.EH bit, which protects some data against double-faults,
is only present with the MMU. Several exception cases did not check
for status.EH being set, as required.
The status.IH bit, which had been set by EXCP_IRQ, is exclusive to
the external interrupt controller, which we do not yet implement.
The internal interrupt controller, when the MMU is also present,
sets the status.EH bit.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-33-richard.henderson@linaro.org>
Decode 'break 1' during translation, rather than doing
it again during exception processing.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-32-richard.henderson@linaro.org>
These symbols become available to the debugger.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-31-richard.henderson@linaro.org>
Use FIELD_EX32 and FIELD_DP32 instead of managing the
masking by hand.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-30-richard.henderson@linaro.org>
WE is the architectural name of the field, not WR.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-29-richard.henderson@linaro.org>
Retain the helper macros for single bit fields as aliases to
the longer R_*_MASK names. Use FIELD_EX32 and FIELD_DP32
instead of manually manipulating the fields.
Since we're rewriting the references to CR_TLBACC_IGN_* anyway,
we correct the name of this field to IG, which is its name in
the official CPU documentation.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-28-richard.henderson@linaro.org>
Use FIELD_EX32 and FIELD_DP32 instead of manual manipulation
of the fields.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-27-richard.henderson@linaro.org>
Use FIELD_DP32 instead of manual shifting and masking.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-26-richard.henderson@linaro.org>
Add all fields; retain the helper macros for single bit fields.
So far there are no uses of the multi-bit status fields.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-25-richard.henderson@linaro.org>
Do not print control registers for user-only mode.
Rename reserved control registers to "resN", where
N is the control register index.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-24-richard.henderson@linaro.org>
Place the control registers into their own array, env->ctrl[].
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-23-richard.henderson@linaro.org>
This function is unused. The real computation of this value
is located in nios2_cpu_exec_interrupt.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-22-richard.henderson@linaro.org>
We don't need to reference them often, and when we do it
is just as easy to load/store from cpu_env directly.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-20-richard.henderson@linaro.org>
We had failed to copy BSTATUS back to STATUS, and diagnose
supervisor-only. The spec is light on the specifics of the
implementation of bret, but it is an easy assumption that
the restore into STATUS should work the same as eret.
Therefore, reuse the existing helper_eret.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-19-richard.henderson@linaro.org>
The implementation of eret will become much more complex
with the introduction of shadow registers.
[rth: Split out of a larger patch for shadow register sets.
Directly exit to the cpu loop from the helper.]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Amir Gonnen <amir.gonnen@neuroblade.ai>
Message-Id: <20220303153906.2024748-3-amir.gonnen@neuroblade.ai>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-18-richard.henderson@linaro.org>
It is cleaner to have a separate name for this variable.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-17-richard.henderson@linaro.org>
Split NUM_CORE_REGS into components that can be used elsewhere.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Amir Gonnen <amir.gonnen@neuroblade.ai>
Message-Id: <20220303153906.2024748-3-amir.gonnen@neuroblade.ai>
[rth: Split out of a larger patch for shadow register sets.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-16-richard.henderson@linaro.org>
Whether the cpu is in user-mode or not is something that we
know at translation-time. We do not need to generate code
after having raised an exception.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-15-richard.henderson@linaro.org>
eret instruction is only allowed in supervisor mode.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Amir Gonnen <amir.gonnen@neuroblade.ai>
Message-Id: <20220303153906.2024748-2-amir.gonnen@neuroblade.ai>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-14-richard.henderson@linaro.org>
Remove the #ifdef !defined(CONFIG_USER_ONLY) that surrounds
the whole file, and move helper.c to nios2_softmmu_ss.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-12-richard.henderson@linaro.org>
Since f5ef0e518d, we have a real page mapped for kuser,
which means the special casing for SIGSEGV can go away.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-11-richard.henderson@linaro.org>
