Commit Graph

26 Commits

Author SHA1 Message Date
James Hogan
d673a68db6 target/mips: Fix RDHWR CC with icount
RDHWR CC reads the CPU timer like MFC0 CP0_Count, so with icount enabled
it must set can_do_io while it calls the helper to avoid the "Bad icount
read" error. It should also break out of the translation loop to ensure
that timer interrupts are immediately handled.

Fixes: 2e70f6efa8 ("Add instruction counter.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-08-02 22:18:13 +01:00
James Hogan
51ca717b07 target/mips: Drop redundant gen_io_start/stop()
DMTC0 CP0_Cause does a redundant gen_io_start() and gen_io_end() pair,
even though this is done for all DMTC0 operations outside of the switch
statement. Remove these redundant calls.

Fixes: 5dc5d9f055 ("mips: more fixes to the MIPS interrupt glue logic")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-08-02 22:18:13 +01:00
James Hogan
b74cddcbf6 target/mips: Use BS_EXCP where interrupts are expected
Commit e350d8ca3a ("target/mips: optimize indirect branches") made
indirect branches able to directly find the next TB and jump straight to
it without breaking out of translated code and going around the main
execution loop. This breaks the assumption in target/mips/translate.c
that BS_STOP is sufficient to cause pending interrupts to be handled,
since interrupts are only checked in the main loop.

Fix a few of these assumptions by using gen_save_pc to update the saved
PC and using BS_EXCP instead of BS_STOP:

 - [D]MFC0 CP0_Count may trigger a timer interrupt which should be
   immediately handled.

 - [D]MTC0 CP0_Cause may trigger an interrupt (but in fact translation
   was only even being stopped in the DMTC0 case).

 - [D]MTC0 CP0_<any> when icount is used is assumed could potentially
   cause interrupts.

 - EI may trigger an interrupt which was pending. I specifically hit
   this case when running KVM nested in mipsel-softmmu. A timer
   interrupt while the 2nd guest was executing is caught by KVM which
   switches back to the normal Linux exception base and re-enables
   interrupts with EI. Since the above commit QEMU doesn't leave
   translated code until the nested KVM has already restored the KVM
   exception base and returned to the 2nd guest, at which point it is
   too late to check for pending interrupts and it gets stuck in an
   infinite loop of unhandled interrupts.

Something similar was needed for ARM in commit b29fd33db5
("target/arm: use DISAS_EXIT for eret handling").

Fixes: e350d8ca3a ("target/mips: optimize indirect branches")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-08-02 22:18:12 +01:00
James Hogan
d3d93c6c1e mips: Add KVM T&E segment support for TCG
MIPS KVM trap & emulate guest kernels have a different segment layout
compared with traditional MIPS kernels, to allow both the user and
kernel code to run from the user address segment without repeatedly
trapping to KVM.

QEMU currently supports this layout only for KVM, but its sometimes
useful to be able to run these kernels in QEMU on a PC, so enable it for
TCG too.

This also paves the way for MIPS KVM VZ support (which uses the normal
virtual memory layout) by abstracting whether user mode kernel segments
are in use.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
[Yongbok Kim:
  minor change]
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-08-02 22:18:06 +01:00
James Hogan
cb539fd241 target-mips: Don't stop on [d]mtc0 DESAVE/KScratch
Writing to the MIPS DESAVE register (and now the KScratch registers)
will stop translation, supposedly due to risk of execution mode
switches. However these registers are basically RW scratch registers
with no side effects so there is no risk of them triggering execution
mode changes.

Drop the bstate = BS_STOP for these registers for both mtc0 and dmtc0.

Fixes: 7a387fffce ("Add MIPS32R2 instructions, and generally straighten out the instruction decoding. This is also the first percent towards MIPS64 support.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-08-02 17:01:27 +01:00
James Hogan
cec56a733d target/mips: Add segmentation control registers
The optional segmentation control registers CP0_SegCtl0, CP0_SegCtl1 &
CP0_SegCtl2 control the behaviour and required privilege of the legacy
virtual memory segments.

Add them to the CP0 interface so they can be read and written when
CP0_Config3.SC=1, and initialise them to describe the standard legacy
layout so they can be used in future patches regardless of whether they
are exposed to the guest.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
James Hogan
b0fc600322 target/mips: Abstract mmu_idx from hflags
The MIPS mmu_idx is sometimes calculated from hflags without an env
pointer available as cpu_mmu_index() requires.

Create a common hflags_mmu_index() for the purpose of this calculation
which can operate on any hflags, not just with an env pointer, and
update cpu_mmu_index() itself and gen_intermediate_code() to use it.

Also update debug_post_eret() and helper_mtc0_status() to log the MMU
mode with the status change (SM, UM, or nothing for kernel mode) based
on cpu_mmu_index() rather than directly testing hflags.

This will also allow the logic to be more easily updated when a new MMU
mode is added.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
James Hogan
8fffc64696 target/mips: Decode microMIPS EVA load & store instructions
Implement decoding of microMIPS EVA load and store instruction groups in
the POOL31C pool. These use the same gen_ld(), gen_st(), gen_st_cond()
helpers as the MIPS32 decoding, passing the equivalent MIPS32 opcodes as
opc.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
James Hogan
7696414729 target/mips: Decode MIPS32 EVA load & store instructions
Implement decoding of MIPS32 EVA loads and stores. These access the user
address space from kernel mode when implemented, so for each instruction
we need to check that EVA is available from Config5.EVA & check for
sufficient COP0 privilege (with the new check_eva()), and then override
the mem_idx used for the operation.

Unfortunately some Loongson 2E instructions use overlapping encodings,
so we must be careful not to prevent those from being decoded when EVA
is absent.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
James Hogan
dd4096cd2c target/mips: Prepare loads/stores for EVA
EVA load and store instructions access the user mode address map, so
they need to use mem_idx of MIPS_HFLAG_UM. Update the various utility
functions to allow mem_idx to be more easily overridden from the
decoding logic.

Specifically we add a mem_idx argument to the op_ld/st_* helpers used
for atomics, and a mem_idx local variable to gen_ld(), gen_st(), and
gen_st_cond().

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
James Hogan
74dbf824a1 target/mips: Add CP0_Ebase.WG (write gate) support
Add support for the CP0_EBase.WG bit, which allows upper bits to be
written (bits 31:30 on MIPS32, or bits 63:30 on MIPS64), along with the
CP0_Config5.CV bit to control whether the exception vector for Cache
Error exceptions is forced into KSeg1.

This is necessary on MIPS32 to support Segmentation Control and Enhanced
Virtual Addressing (EVA) extensions (where KSeg1 addresses may not
represent an unmapped uncached segment).

It is also useful on MIPS64 to allow the exception base to reside in
XKPhys, and possibly out of range of KSEG0 and KSEG1.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
[yongbok.kim@imgtec.com:
  minor changes]
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
James Hogan
e40df9a80b target/mips: Fix MIPS64 MFC0 UserLocal on BE host
Using MFC0 to read CP0_UserLocal uses tcg_gen_ld32s_tl, however
CP0_UserLocal is a target_ulong. On a big endian host with a MIPS64
target this reads and sign extends the more significant half of the
64-bit register.

Fix this by using ld_tl to load the whole target_ulong and ext32s_tl to
sign extend it, as done for various other target_ulong COP0 registers.

Fixes: d279279e2b ("target-mips: implement UserLocal Register")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-20 22:42:26 +01:00
Lluís Vilanova
9c489ea6be tcg: Pass generic CPUState to gen_intermediate_code()
Needed to implement a target-agnostic gen_intermediate_code()
in the future.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Benneé <alex.benee@linaro.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-Id: <150002025498.22386.18051908483085660588.stgit@frigg.lan>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-07-19 14:45:16 -07:00
Aurelien Jarno
06a57e5cc7 target/mips: optimize WSBH, DSBH and DSHD
Use the same mask to avoid having to load two different constants.

Suggested-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2017-07-17 16:48:21 +02:00
Miodrag Dinic
cab4888136 target/mips: fix msa copy_[s|u]_df rd = 0 corner case
This patch fixes the msa copy_[s|u]_df instruction emulation when
the destination register rd is zero. Without this patch the zero
register would get clobbered, which should never happen because it
is supposed to be hardwired to 0.

Fix this corner case by explicitly checking rd = 0 and effectively
making these instructions emulation no-op in that case.

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-07-11 15:06:34 +01:00
Aurelien Jarno
e350d8ca3a target/mips: optimize indirect branches
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20170430145254.25616-4-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-06-05 09:25:42 -07:00
Aurelien Jarno
d9a9acde64 target/mips: optimize cross-page direct jumps in softmmu
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20170430145254.25616-3-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-06-05 09:25:42 -07:00
Yongbok Kim
075a1fe788 target/mips: fix delay slot detection in gen_msa_branch()
It is unnecessary to test R6 from delay/forbidden slot check
in gen_msa_branch().

https://bugs.launchpad.net/qemu/+bug/1663287

Reported-by: Brian Campbell <bacam@z273.org.uk>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-03-20 11:19:14 +00:00
Philippe Mathieu-Daudé
b44a7fb14e target-mips: replace few LOG_DISAS() with trace points
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-03-20 11:06:32 +00:00
Philippe Mathieu-Daudé
3570d7f667 target-mips: replace break by goto cp0_unimplemented
this fixes many warnings like:

target/mips/translate.c:6253:13: warning: Value stored to 'rn' is never read
            rn = "invalid sel";
            ^    ~~~~~~~~~~~~~

Reported-by: Clang Static Analyzer
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-03-20 11:06:32 +00:00
Philippe Mathieu-Daudé
965447eecb target-mips: log bad coprocessor0 register accesses with LOG_UNIMP
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-03-20 11:06:32 +00:00
Philippe Mathieu-Daudé
989f2aa9af target-mips: remove old & unuseful comments
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-03-20 11:06:32 +00:00
Paul Burton
bed9e5ceb1 target-mips: Provide function to test if a CPU supports an ISA
Provide a new cpu_supports_isa function which allows callers to
determine whether a CPU supports one of the ISA_ flags, by testing
whether the associated struct mips_def_t sets the ISA flags in its
insn_flags field.

An example use of this is to allow boards which generate bootloader code
to determine the properties of the CPU that will be used, for example
whether the CPU is 64 bit or which architecture revision it implements.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-02-21 22:24:58 +00:00
Richard Henderson
1a0196c5c7 target-mips: Use clz opcode
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-01-10 08:06:11 -08:00
Richard Henderson
6eebb7a438 target-mips: Use the new extract op
Use extract for EXT and DEXT.

Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-01-10 08:06:10 -08:00
Thomas Huth
fcf5ef2ab5 Move target-* CPU file into a target/ folder
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.

Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [cris&microblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
2016-12-20 21:52:12 +01:00