Load/store opcodes may raise MMU exceptions. Normally exceptions should
be checked in priority order before any actual operations, but since MMU
exceptions are tightly coupled with actual memory access, there's
currently no way to do it.
Approximate this behavior by executing all load, then all store, and
then all other opcodes in the FLIX bundles. Use opcode dependency
mechanism to express ordering. Mark load/store opcodes with
XTENSA_OP_{LOAD,STORE} flags. Newer libisa has classifier functions that
can tell whether opcode is a load or store, but this information is not
available in the existing overlays.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Currently topologic opcode sorting stops at the first detected
dependency loop. Introduce struct opcode_arg_copy that describes
temporary register copy. Scan remaining opcodes searching for
dependencies that can be broken, break them by introducing temporary
register copies and record them in an array. In case of success
create local temporaries and initialize them with current register
values. Share single temporary copy between all register users. Delete
temporaries after translation.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
libisa represents boolean registers b0..b16 as a BR register file and as
BR4 and BR8 register groups. Add these register files and use
OpcodeArg::{in,out} parameters to access boolean registers in
translators.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
libisa represents MAC16 registers m0..m3 as an MR register file. Add
this register file and reference its registers directly from the
translate_mac16. Drop translator parameter that indicates whether opcode
argument is in ar or in mr.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
To support circular register dependencies in FLIX bundles opcode inputs
and outputs must be separate and adjustable. Circular dependencies can
be broken by making temporary copies of opcode inputs and substituting
them into the arguments array instead of the original registers.
E.g. the circular register dependency in the following bundle:
{ mov a2, a3 ; mov a3, a2 }
can be resolved by making copy a2' = a2 and substituting it as input
argument of the second opcode:
{ mov a2, a3 ; mov a3, a2' }
Change opcode translator prototype to accept OpcodeArg array as
argument. For each register argument initialize OpcodeArg::{in,out} with
TCGv_* of the respective register. Don't explicitly use cpu_R in the
opcode translators, use OpcodeArg::{in,out} instead.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Move return address calculation and WINDOW_START adjustment out of the
retw helper to simplify logic a bit and avoid using registers directly.
Pass a0 as a parameter to the helper.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Opcodes that modify WINDOW_BASE SR don't have dependency on opcodes that
use windowed registers. If such opcodes are combined in a single
instruction they may not be correctly ordered. Instead of adding said
dependency use temporary register to store changed WINDOW_BASE value and
do actual register window rotation as a postprocessing step.
Not all opcodes that change WINDOW_BASE need this: retw, rfwo and rfwu
are also jump opcodes, so they are guaranteed to be translated last and
thus will not affect other opcodes in the same instruction.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Some opcodes may need additional actions at every exit from the
translated instruction or may need to amend TB exit slots available to
jumps generated for the instruction. Add gen_postprocess function and
call it from the gen_jump_slot and from the disas_xtensa_insn.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Opcodes in different slots may read and write same resources (registers,
states). In the absence of resource dependency loops it must be possible
to sort opcodes to avoid interference.
Record resources used by each opcode in the bundle. Build opcode
dependency graph and use topological sort to order its nodes. In case of
success translate opcodes in sort order. In case of failure report and
raise invalid opcode exception.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
FLIX adds branch and loop instruction variants with 15- and 18-bit wide
target offset. Implement them as additional names for the ordinary
branch/loop opcodes.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There are opcodes that differ only in encoding or possible range of
immediate arguments. Allow multiple names for single opcode translation
table entry to reduce code duplication in that case.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Requirement for alphabetical opcode sorting in opcode tables is awkward
and does not allow sharing implementation between multiple opcodes.
Use hash tables to find opcodes by name. Move implementation from the
translate.c to the helper.c to its only user and remove declaration from
the cpu.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Don't run xtensa_finalize_config at the time of core registration,
instead run it at the CPU class initialization.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa-modules part of the test_mmuhifi_c3 core is missing fixes that
returns XTENSA_UNDEFINED for undefined opcodes and marks all data
structures static. Run sed script from target/xtensa/import_core.sh on
it. This fixes test_sr tests for missing special registers.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Merge gen_callwi and gen_callw into their only users, translate_callw
and translate_callxw. Extract jump slot adjustment logic into a separate
function and use it in gen_jumpi and translate_callw.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Use libisa to extract whether opcode uses windowed registers and
construct mask based on that. This only leaves special case for the
'entry' opcode, as it needs to probe a register dynamically.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa-modules.c produced by recent Tensilica tools have
Opcode_*_encode_fns arrays defined as static. Don't add extra 'static'
in front of them when importing.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Runstall signal looks very much like a level-triggered IRQ line. Provide
xtensa_get_runstall function that returns runstall IRQ.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Replace xtensa_get_extint that returns single external IRQ descriptor
with xtensa_get_extints that returns a vector of all external IRQs.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
It's a one-liner used in a single place, move its implementation there
and remove its declaration.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
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>
When xtensa_runstall is called to unstall a core it needs to kick it
after clearing runstall flag, otherwise the core doesn't start
immediately. There's also no point in clearing CPU_INTERRUPT_HALT, drop
it.
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>
Now that xtensa_count_regs does the right thing, remove manual
initialization of these fields from the affected configurations and let
xtensa_finalize_config initialize them. Add XTREG_END to terminate
register lists.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
In order to communicate correctly with gdb xtensa gdbstub must provide
expected number of registers in 'g' packet response. xtensa-elf-gdb
expects both nonprivileged and privileged registers. xtensa-linux-gdb
only expects nonprivileged registers. gdb only counts one contiguous
stretch of registers, do the same for the core registers in the
xtensa_count_regs.
With this change qemu-system-xtensa is able to communicate with all
xtensa-elf-gdb versions (versions prior to 8.2 require overlay fixup),
and qemu-xtensa is able to communicate with all xtensa-linux-gdb
versions, except 8.2.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- mark instructions that affect active IRQ level;
- put call for gen_check_interrupts right after the instruction
translation; when FLIX is enabled it will need to appear before
other exits from the TB as well;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Now that all logic for TB termination is extracted from rsr/wsr their
return value is not used and may be dropped.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- mark instructions that require TB termination via slot 0;
- put TB termination right after the instruction translation loop, if
termination w/o TB linking wasn't requested;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Currently we only end TB in icount mode, because access to CCOUNT or
write to CCOMPARE are IO operations. Simplify the behaviour a bit and
end TB unconditionally.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Opcode decoding with libisa takes care about range of valid group SRs,
like CCOMPARE, IBREAKA, DBREAKA or DBREAKC. Turn range checks in wsr
implementations into assertions.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- mark all instructions that exit TB and require dynamic search for the
next TB;
- put TB termination right after the instruction translation loop;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- mark quos/quou/rems/remu instructions;
- drop parameter 0 from the translate_quou and split translate_remu from
it;
- put test for division by zero exception right after the coprocessor
exception test;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- add XtensaOpcodeOps::coprocessor with bitmask of coprocessors used by
the instruction;
- replace coprocessor id parameter of gen_check_cpenable with the
bitmask of used coprocessors;
- collect coprocessor IDs used by an instruction in the disassembly
loop;
- put test for coprocessor disabled exception after the alloca test;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- 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>
- mark break and break.n instructions;
- collect debug cause bits from parameter 0 of instructions marked for
debug exception;
- put debug exception check right after syscall check;
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- mark privileged instructions;
- put single privileged instruction check after disassembly loop;
- translate_[di]cache: drop parameter 0, shift parameters one down;
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>
Complete xtensa-semi chardev console implementation: allow reading input
characters from file descriptor 0 and call sys_select_one simcall on it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
