The Exclusive Instructions provide a general-purpose mechanism for
atomic updates of memory-based synchronization variables that can be
used for exclusion algorithms.
Use cmpxchg-based implementation that is sufficient for the typical use
of exclusive access in atomic operations.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
INTERRUPT special register may be changed both by the core (by writing
to INTSET and INTCLEAR registers) and by external events (by triggering
and clearing HW IRQs). In MTTCG this state must be protected from
concurrent access, otherwise interrupts may be lost or spurious
interrupts may be detected.
Use atomic operations to change INTSET SR.
Fix wsr.intset so that it soesn't clear any bits.
Fix wsr.intclear so that it doesn't clear bit that corresponds to NMI.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Move helper functions related to interrupt and exception handling from
op_helper.c and helper.c to exc_helper.c. No functional changes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Move HELPER functions related to native debugging from op_helper.c to
dbg_helper.c. No functional changes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Move MMU-related helper functions from op_helper.c and helper.c to
mmu_helper.c. No functional changes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Move helper functions related to register windows from op_helper.c to
win_helper.c. No functional changes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Don't invalidate TB with the end of zero overhead loop when LBEG or LEND
change. Instead encode the distance from the start of the page where the
TB starts to the LEND in the TB cs_base and generate loopback code when
the next PC matches encoded LEND. Distance to a destination within the
same page and up to a maximum instruction length into the next page is
encoded literally, otherwise it's zero. The distance from LEND to LBEG
is also encoded in the cs_base: it's encoded literally when less than
256 or as 0 otherwise. This allows for TB chaining for the loopback
branch at the end of a loop for the most common loop sizes.
With this change the resulting emulation speed is about 10% higher in
softmmu mode on uClibc-ng and LTP tests. Emulation speed in linux
user mode is a few percent lower because there's no direct TB chaining
between different memory pages. Testing with lower limit on direct TB
chaining range shows gradual slowdown to ~15% for the block size of 64
bytes and ~50% for the block size of 32 bytes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
- mark retw and retw.n instructions;
- extract window inderflow test from retw helper;
- put underflow exception check generation right after the overflow
check;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- add ps.callinc to the TB flags, that allows testing all instructions
for window overflow statically;
- drop gen_window_check* functions; replace them with get_window_check
that accepts bitmask of used registers;
- add XtensaOpcodeOps::test_overflow that returns bitmask of implicitly
used registers; use it for entry and call{,x}{4,8,12};
- drop window overflow test from the entry helper;
- drop parameter 0 from translate_[di]cache and use translate_nop for
d/i cache opcodes that don't need memory accessibility check;
- add bitmask XtensaOpcodeOps::windowed_register_op that marks opcode
arguments that refer to windowed registers;
- translate windowed_register_op mask to a mask of actually used
registers in the disassembly loop;
- add check for window overflow right after the check for debug
exception;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- TB flags: add XTENSA_TBFLAG_CWOE that corresponds to the architectural
CWOE state;
- entry: move CWOE check from the helper to the test_ill_entry;
- retw: move CWOE check from the helper to the test_ill_retw;
- separate instruction disassembly loop and translation loop; save
disassembly results in local array;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
The xtensa frontend calls get_page_addr_code() from its
itlb_hit_test helper function. This function is really part
of the TCG core's internals, and calling it from a target
helper makes it awkward to make changes to that core code.
It also means that we don't pass the correct retaddr to
tlb_fill(), so we won't correctly handle the case where
an exception is generated.
The helper is used for the instructions IHI, IHU and IPFL.
Change it to call cpu_ldb_code_ra() instead.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Place them in exec.c, exec-all.h and ram_addr.h. This removes
knowledge of translate-all.h (which is an internal header) from
several files outside accel/tcg and removes knowledge of
AddressSpace from translate-all.c (as it only operates on ram_addr_t).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As part of plumbing MemTxAttrs down to the IOMMU translate method,
add MemTxAttrs as an argument to tb_invalidate_phys_addr().
Its callers either have an attrs value to hand, or don't care
and can use MEMTXATTRS_UNSPECIFIED.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180521140402.23318-3-peter.maydell@linaro.org
In icount mode, instructions that access io memory spaces in the middle
of the translation block invoke TB recompilation. After recompilation,
such instructions become last in the TB and are allowed to access io
memory spaces.
When the code includes instruction like i386 'xchg eax, 0xffffd080'
which accesses APIC, QEMU goes into an infinite loop of the recompilation.
This instruction includes two memory accesses - one read and one write.
After the first access, APIC calls cpu_report_tpr_access, which restores
the CPU state to get the current eip. But cpu_restore_state_from_tb
resets the cpu->can_do_io flag which makes the second memory access invalid.
Therefore the second memory access causes a recompilation of the block.
Then these operations repeat again and again.
This patch moves resetting cpu->can_do_io flag from
cpu_restore_state_from_tb to cpu_loop_exit* functions.
It also adds a parameter for cpu_restore_state which controls restoring
icount. There is no need to restore icount when we only query CPU state
without breaking the TB. Restoring it in such cases leads to the
incorrect flow of the virtual time.
In most cases new parameter is true (icount should be recalculated).
But there are two cases in i386 and openrisc when the CPU state is only
queried without the need to break the TB. This patch fixes both of
these cases.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180409091320.12504.35329.stgit@pasha-VirtualBox>
[rth: Make can_do_io setting unconditional; move from cpu_exec;
make cpu_loop_exit_{noexc,restore} call cpu_loop_exit.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Import list of syscalls from the kernel source. Conditionalize code/data
that is only used with softmmu. Implement exception handlers. Implement
signal hander (only the core registers for now, no coprocessors or TIE).
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
As cpu.h is another typically widely included file which doesn't need
full access to the softfloat API we can remove the includes from here
as well. Where they do need types it's typically for float_status and
the rounding modes so we move that to softfloat-types.h as well.
As a result of not having softfloat in every cpu.h call we now need to
add it to various helpers that do need the full softfloat.h
definitions.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[For PPC parts]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
The MC68040 MMU provides the size of the access that
triggers the page fault.
This size is set in the Special Status Word which
is written in the stack frame of the access fault
exception.
So we need the size in m68k_cpu_unassigned_access() and
m68k_cpu_handle_mmu_fault().
To be able to do that, this patch modifies the prototype of
handle_mmu_fault handler, tlb_fill() and probe_write().
do_unassigned_access() already includes a size parameter.
This patch also updates handle_mmu_fault handlers and
tlb_fill() of all targets (only parameter, no code change).
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180118193846.24953-2-laurent@vivier.eu>
Currently 'entry' opcode helper accepts frame size divided by 8, as it
is encoded in the opcode. Make it more natural and accept actual frame
size instead.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Instead of using the hardcoded (MemTxAttrs){0} for no memory attributes
let's use the already defined MEMTXATTRS_UNSPECIFIED macro instead.
This is technically a change of behaviour as MEMTXATTRS_UNSPECIFIED sets
the unspecified field to 1, but it doesn't look like anything is
checking this field.
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Make sure we have the BQL held when processing interrupts.
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
RER and WER are privileged instructions for accessing external
registers. External register address space is local to processor core.
There's no alignment requirements, addressable units are 32-bit wide
registers.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Delimit each instruction that may access timers or IRQ state with
qemu_io_start/qemu_io_end, so that qemu-system-xtensa could be run with
-icount option.
Raise EXCP_YIELD after CCOMPARE reprogramming to let tcg_cpu_exec
recalculate how long this CPU is allowed to run.
RSR now may need to terminate TB, but it can't be done in RSR handler
because the same handler is used for XSR together with WSR handler, which
may also need to terminate TB. Change RSR and WSR handlers return type
to bool indicating whether TB termination is needed (RSR) or has been
done (WSR), and add TB termination after RSR/WSR dispatcher call.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Xtensa cores may have a register (CCOUNT) that counts core clock cycles.
It may also have a number of registers (CCOMPAREx); when CCOUNT value
passes the value of CCOMPAREx, timer interrupt x is raised.
Currently xtensa target counts a number of completed instructions and
assumes that for CCOUNT one instruction takes one cycle to complete.
It calls helper function to update CCOUNT register at every TB end and
raise timer interrupts. This scheme works very predictably and doesn't
have noticeable performance impact, but it is hard to use with multiple
synchronized processors, especially with coming MTTCG.
Derive CCOUNT from the virtual simulation time, QEMU_CLOCK_VIRTUAL.
Use native QEMU timers for CCOMPARE timers, one timer for each register.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
We have never has the concept of global TLB entries which would avoid
the flush so we never actually use this flag. Drop it and make clear
that tlb_flush is the sledge-hammer it has always been.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
[DG: ppc portions]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
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> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Max Filippov