Commit Graph

194 Commits

Author SHA1 Message Date
Philippe Mathieu-Daudé
6d2d454a88 target/cpu: Restrict cpu_get_phys_page_debug() handlers to sysemu
The 'hwaddr' type is only available / meaningful on system emulation.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221216215519.5522-5-philmd@linaro.org>
2023-02-27 22:29:01 +01:00
Markus Armbruster
a67dfa660b Drop duplicate #include
Tracked down with the help of scripts/clean-includes.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230202133830.2152150-21-armbru@redhat.com>
2023-02-08 07:28:05 +01:00
Peter Maydell
4245a71662 target/nios2: Convert to 3-phase reset
Convert the nios2 CPU class to use 3-phase reset, so it doesn't
need to use device_class_set_parent_reset() any more.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Edgar E. Iglesias <edgar@zeroasic.com>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Message-id: 20221124115023.2437291-12-peter.maydell@linaro.org
2022-12-16 15:58:15 +00:00
Richard Henderson
3d419a4dd2 accel/tcg: Remove will_exit argument from cpu_restore_state
The value passed is always true, and if the target's
synchronize_from_tb hook is non-trivial, not exiting
may be erroneous.

Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-11-01 08:31:41 +11:00
Richard Henderson
fbd5bd4ebc target/nios2: Convert to tcg_ops restore_state_to_opc
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-10-26 11:11:28 +10:00
Richard Henderson
e4fdf9df5b hw/core: Add CPUClass.get_pc
Populate this new method for all targets.  Always match
the result that would be given by cpu_get_tb_cpu_state,
as we will want these values to correspond in the logs.

Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> (target/sparc)
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Eduardo Habkost <eduardo@habkost.net> (supporter:Machine core)
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com> (supporter:Machine core)
Cc: "Philippe Mathieu-Daudé" <f4bug@amsat.org> (reviewer:Machine core)
Cc: Yanan Wang <wangyanan55@huawei.com> (reviewer:Machine core)
Cc: Michael Rolnik <mrolnik@gmail.com> (maintainer:AVR TCG CPUs)
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com> (maintainer:CRIS TCG CPUs)
Cc: Taylor Simpson <tsimpson@quicinc.com> (supporter:Hexagon TCG CPUs)
Cc: Song Gao <gaosong@loongson.cn> (maintainer:LoongArch TCG CPUs)
Cc: Xiaojuan Yang <yangxiaojuan@loongson.cn> (maintainer:LoongArch TCG CPUs)
Cc: Laurent Vivier <laurent@vivier.eu> (maintainer:M68K TCG CPUs)
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> (reviewer:MIPS TCG CPUs)
Cc: Aleksandar Rikalo <aleksandar.rikalo@syrmia.com> (reviewer:MIPS TCG CPUs)
Cc: Chris Wulff <crwulff@gmail.com> (maintainer:NiosII TCG CPUs)
Cc: Marek Vasut <marex@denx.de> (maintainer:NiosII TCG CPUs)
Cc: Stafford Horne <shorne@gmail.com> (odd fixer:OpenRISC TCG CPUs)
Cc: Yoshinori Sato <ysato@users.sourceforge.jp> (reviewer:RENESAS RX CPUs)
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> (maintainer:SPARC TCG CPUs)
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> (maintainer:TriCore TCG CPUs)
Cc: Max Filippov <jcmvbkbc@gmail.com> (maintainer:Xtensa TCG CPUs)
Cc: qemu-arm@nongnu.org (open list:ARM TCG CPUs)
Cc: qemu-ppc@nongnu.org (open list:PowerPC TCG CPUs)
Cc: qemu-riscv@nongnu.org (open list:RISC-V TCG CPUs)
Cc: qemu-s390x@nongnu.org (open list:S390 TCG CPUs)
2022-10-04 12:13:12 -07:00
Peter Maydell
cab9f19370 target/nios2: Honour -semihosting-config userspace=on
Honour the commandline -semihosting-config userspace=on option,
instead of always permitting userspace semihosting calls in system
emulation mode, by passing the correct value to the is_userspace
argument of semihosting_enabled().

Note that this is a behaviour change: if the user wants to
do semihosting calls from userspace they must now specifically
enable them on the command line.

nios2 semihosting is not implemented for linux-user builds.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-6-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-09-13 17:18:21 +01:00
Peter Maydell
5202861b20 semihosting: Allow optional use of semihosting from userspace
Currently our semihosting implementations generally prohibit use of
semihosting calls in system emulation from the guest userspace.  This
is a very long standing behaviour justified originally "to provide
some semblance of security" (since code with access to the
semihosting ABI can do things like read and write arbitrary files on
the host system).  However, it is sometimes useful to be able to run
trusted guest code which performs semihosting calls from guest
userspace, notably for test code.  Add a command line suboption to
the existing semihosting-config option group so that you can
explicitly opt in to semihosting from guest userspace with
 -semihosting-config userspace=on

(There is no equivalent option for the user-mode emulator, because
there by definition all code runs in userspace and has access to
semihosting already.)

This commit adds the infrastructure for the command line option and
adds a bool 'is_user' parameter to the function
semihosting_userspace_enabled() that target code can use to check
whether it should be permitting the semihosting call for userspace.
It mechanically makes all the callsites pass 'false', so they
continue checking "is semihosting enabled in general".  Subsequent
commits will make each target that implements semihosting honour the
userspace=on option by passing the correct value and removing
whatever "don't do this for userspace" checking they were doing by
hand.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-2-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-09-13 17:18:21 +01:00
Richard Henderson
78c2c68dda target/nios2: Convert semihosting errno to gdb remote errno
The semihosting abi used by nios2 uses the gdb remote
protocol filesys errnos.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-09-13 17:18:20 +01:00
Richard Henderson
d1e23cbaa4 target/nios2: Use semihosting/syscalls.h
This separates guest file descriptors from host file descriptors,
and utilizes shared infrastructure for integration with gdbstub.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-09-13 17:18:20 +01:00
Richard Henderson
306c872103 accel/tcg: Add pc and host_pc params to gen_intermediate_code
Pass these along to translator_loop -- pc may be used instead
of tb->pc, and host_pc is currently unused.  Adjust all targets
at one time.

Acked-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-09-06 08:04:26 +01:00
Richard Henderson
ca97e0ef99 target/nios2: Move nios2-semi.c to nios2_softmmu_ss
Semihosting is not enabled for nios2-linux-user.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 10:18:57 +05:30
Richard Henderson
79cc9724c2 target/nios2: Eliminate nios2_semi_is_lseek
Reorg nios2_semi_return_* to gdb_syscall_complete_cb.
Use the 32-bit version normally, and the 64-bit version
for HOSTED_LSEEK.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 10:18:47 +05:30
Richard Henderson
64c8c6a992 gdbstub: Adjust gdb_syscall_complete_cb declaration
Change 'ret' to uint64_t.  This resolves a FIXME in the
m68k and nios2 semihosting that we've lost data.
Change 'err' to int.  There is nothing target-specific
about the width of the errno value.

Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 04:35:52 +05:30
Richard Henderson
7c56c2d3da include/exec: Move gdb_stat and gdb_timeval to gdbstub.h
We have two copies of these structures, and require them
in semihosting/ going forward.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 04:35:07 +05:30
Richard Henderson
94b14fe08f include/exec: Move gdb open flags to gdbstub.h
There were 3 copies of these flags.  Place them in the
file with gdb_do_syscall, with which they belong.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 04:35:07 +05:30
Richard Henderson
c89a14ad2c semihosting: Move exec/softmmu-semi.h to semihosting/softmmu-uaccess.h
We have a subdirectory for semihosting; move this file out of exec.
Rename to emphasize the contents are a replacement for the functions
in linux-user/bsd-user uaccess.c.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-28 04:35:06 +05:30
Markus Armbruster
4f31b54bfe Normalize header guard symbol definition
We commonly define the header guard symbol without an explicit value.
Normalize the exceptions.

Done with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220506134911.2856099-4-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2022-05-11 16:50:26 +02:00
Richard Henderson
e84f176844 target/nios2: Advance pc when raising exceptions
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
a25c4eff32 target/nios2: Implement EIC interrupt processing
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
6bcc59cafa target/nios2: Update helper_eret for shadow registers
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
3a03087019 target/nios2: Implement rdprs, wrprs
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
945a5bd3f8 target/nios2: Introduce shadow register sets
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
410c6aaa3b target/nios2: Implement Misaligned destination exception
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
0e6f22c561 target/nios2: Use tcg_gen_lookup_and_goto_ptr
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
5b843284d8 target/nios2: Use gen_goto_tb for DISAS_TOO_MANY
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
3ad5935c58 target/nios2: Hoist set of is_jmp into gen_goto_tb
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
bd9154aa2b target/nios2: Create gen_jumpr
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
0706ac0f86 target/nios2: Enable unaligned traps for system mode
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
d2293ebb04 target/nios2: Drop CR_STATUS_EH from tb->flags
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
7eed8e4003 target/nios2: Introduce dest_gpr
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>
2022-04-26 08:17:05 -07:00
Richard Henderson
541cb627da target/nios2: Split out helpers for gen_rr_shift
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>
2022-04-26 08:17:02 -07:00
Richard Henderson
3099c41bee target/nios2: Split out helpers for gen_rr_mul_high
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>
2022-04-26 08:16:58 -07:00
Richard Henderson
7c849046af target/nios2: Split out helpers for gen_r_math_logic
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>
2022-04-26 08:16:55 -07:00
Richard Henderson
cd419bc63d target/nios2: Split out helpers for gen_i_math_logic
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>
2022-04-26 08:16:52 -07:00
Richard Henderson
3d1f63d019 target/nios2: Split out helpers for gen_i_cmpxx
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
1746338ed6 target/nios2: Split out named structs for [IRJ]_TYPE
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
718db07714 target/nios2: Use tcg_constant_tl
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
345b7a8757 target/nios2: Support division error exception
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
e8d12542ee target/nios2: Remove CPU_INTERRUPT_NMI
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
2de70d2d96 target/nios2: Implement CR_STATUS.RSIE
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
b05550af11 target/nios2: Implement cpuid
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
796945d596 target/nios2: Prevent writes to read-only or reserved control fields
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
be77e1d5fe target/nios2: Clean up handling of tlbmisc in do_exception
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
34cccb7462 target/nios2: Cleanup set of CR_EXCEPTION for do_interrupt
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
af95a70a06 target/nios2: Handle EXCP_UNALIGN and EXCP_UNALIGND
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
0e0824a1a9 target/nios2: Hoist CPU_LOG_INT logging
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
d8c5521cc4 target/nios2: Clean up nios2_cpu_do_interrupt
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
24ca31346e target/nios2: Create EXCP_SEMIHOST for semi-hosting
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>
2022-04-26 08:16:41 -07:00
Richard Henderson
bdb307b4d8 target/nios2: Move R_FOO and CR_BAR into enumerations
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>
2022-04-26 08:16:41 -07:00