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2017-09-06target/arm: [tcg] Port to generic translation frameworkLluís Vilanova1-87/+22
Tested-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-Id: <150002631325.22386.10348327185029496649.stgit@frigg.lan> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to disas_logLluís Vilanova1-5/+13
Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Benneé <alex.benee@linaro.org> Message-Id: <150002582711.22386.191527630537864599.stgit@frigg.lan> [rth: Move tb->size computation and use that result.] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to tb_stopLluís Vilanova1-77/+84
Incrementally paves the way towards using the generic instruction translation loop. Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-Id: <150002534291.22386.13499916738708680298.stgit@frigg.lan> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to translate_insnLluís Vilanova1-75/+90
Incrementally paves the way towards using the generic instruction translation loop. Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-Id: <150002485863.22386.13949856269576226529.stgit@frigg.lan> [rth: Adjust for translate_insn interface change.] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg,a64] Port to insn_startLluís Vilanova1-20/+35
Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Benneé <alex.benee@linaro.org> Message-Id: <150002413187.22386.156315485813606121.stgit@frigg.lan> [rth: Use DISAS_TOO_MANY for "execute only one more" after bp.] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to insn_startLluís Vilanova1-4/+11
Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Benneé <alex.benee@linaro.org> Message-Id: <150002388959.22386.12439646324427589940.stgit@frigg.lan> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to tb_startLluís Vilanova1-38/+44
Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Benneé <alex.benee@linaro.org> Message-Id: <150002364681.22386.1701754996184325808.stgit@frigg.lan> [rth: Adjust for tb_start interface change.] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to init_disas_contextLluís Vilanova1-38/+50
Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Benneé <alex.benee@linaro.org> Message-Id: <150002316201.22386.12115078843605656029.stgit@frigg.lan> [rth: Adjust for max_insns interface change.] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: [tcg] Port to DisasContextBaseLluís Vilanova1-59/+58
Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Benneé <alex.benee@linaro.org> Message-Id: <150002291931.22386.11441154993010495674.stgit@frigg.lan> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: Delay check for magic kernel pageRichard Henderson1-11/+11
There's nothing magic about the exception that we generate in order to execute the magic kernel page. We can and should allow gdb to set a breakpoint at this location. Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target: [tcg] Use a generic enum for DISAS_ valuesLluís Vilanova1-1/+1
Used later. An enum makes expected values explicit and bounds the value space of switches. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-Id: <150002049746.22386.2316077281615710615.stgit@frigg.lan> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-06target/arm: Use DISAS_NORETURNRichard Henderson1-6/+8
Fold DISAS_EXC and DISAS_TB_JUMP into DISAS_NORETURN. In both cases all following code is dead. In the first case because we have exited the TB via exception; in the second case because we have exited the TB via goto_tb and its associated machinery. Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-09-04target/arm: Make arm_cpu_dump_state() handle the M-profile XPSRPeter Maydell1-18/+40
Make the arm_cpu_dump_state() debug logging handle the M-profile XPSR rather than assuming it's an A-profile CPSR. On M profile the PSR line of a register dump will now look like this: XPSR=41000000 -Z-- T priv-thread Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 1501692241-23310-12-git-send-email-peter.maydell@linaro.org
2017-09-04target/arm: Tighten up Thumb decode where new v8M insns will bePeter Maydell1-9/+39
Tighten up the T32 decoder in the places where new v8M instructions will be: * TT/TTT/TTA/TTAT are in what was nominally LDREX/STREX r15, ... which is UNPREDICTABLE: make the UNPREDICTABLE behaviour be to UNDEF * BXNS/BLXNS are distinguished from BX/BLX via the low 3 bits, which in previous architectural versions are SBZ: enforce the SBZ via UNDEF rather than ignoring it, and move the "ARCH(5)" UNDEF case up so we don't leak a TCG temporary * SG is in the encoding which would be LDRD/STRD with rn = r15; this is UNPREDICTABLE and we currently UNDEF: move this check further up the code so that we don't leak TCG temporaries in the UNDEF case and have a better place to put the SG decode. This means that if a v8M binary is accidentally run on v7M or if a test case hits something that we haven't implemented yet the behaviour will be obvious (UNDEF) rather than obscure (plough on treating it as a different instruction). In the process, add some comments about the instruction patterns at these points in the decode. Our Thumb and ARM decoders are very difficult to understand currently, but gradually adding comments like this should help to clarify what exactly has been decoded when. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 1501692241-23310-5-git-send-email-peter.maydell@linaro.org
2017-07-19tcg: Pass generic CPUState to gen_intermediate_code()Lluís Vilanova1-3/+3
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>
2017-07-19target/arm: optimize aarch32 rev16Aurelien Jarno1-2/+4
Use the same mask to avoid having to load two different constants, as suggested by Richard Henderson. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-Id: <20170516230159.4195-2-aurelien@aurel32.net> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-07-17target/arm: use DISAS_EXIT for eret handlingAlex Bennée1-2/+4
Previously DISAS_JUMP did ensure this but with the optimisation of 8a6b28c7 (optimize indirect branches) we might not leave the loop. This means if any pending interrupts are cleared by changing IRQ flags we might never get around to servicing them. You usually notice this by seeing the lookup_tb_ptr() helper gainfully chaining TBs together while cpu->interrupt_request remains high and the exit_request has not been set. This breaks amongst other things the OPTEE test suite which executes an eret from the secure world after a non-secure world IRQ has gone pending which then never gets serviced. Instead of using the previously implied semantics of DISAS_JUMP we use DISAS_EXIT which will always exit the run-loop. CC: Etienne Carriere <etienne.carriere@linaro.org> CC: Joakim Bech <joakim.bech@linaro.org> CC: Jaroslaw Pelczar <j.pelczar@samsung.com> CC: Peter Maydell <peter.maydell@linaro.org> CC: Emilio G. Cota <cota@braap.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 20170713141928.25419-7-alex.bennee@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-07-17target/arm: use gen_goto_tb for ISB handlingAlex Bennée1-2/+2
While an ISB will ensure any raised IRQs happen on the next instruction it doesn't cause any to get raised by itself. We can therefore use a simple tb exit for ISB instructions and rely on the exit_request check at the top of each TB to deal with exiting if needed. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 20170713141928.25419-6-alex.bennee@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-07-17target/arm/translate: ensure gen_goto_tb sets exit flagsAlex Bennée1-1/+5
As the gen_goto_tb function can do both static and dynamic jumps it should also set the is_jmp field. This matches the behaviour of the a64 code. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 20170713141928.25419-5-alex.bennee@linaro.org [tweak to multiline comment formatting] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-07-17target/arm/translate: make DISAS_UPDATE match declared semanticsAlex Bennée1-3/+3
DISAS_UPDATE should be used when the wider CPU state other than just the PC has been updated and we should therefore exit the TCG runtime and return to the main execution loop rather assuming DISAS_JUMP would do that. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 20170713141928.25419-3-alex.bennee@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-05target/arm: optimize indirect branchesEmilio G. Cota1-9/+16
Speed up indirect branches by jumping to the target if it is valid. Softmmu measurements (see later commit for user-mode results): Note: baseline (i.e. speedup == 1x) is QEMU v2.9.0. - Impact on Boot time | setup | ARM debian jessie boot+shutdown time | stddev | |--------+--------------------------------------+--------| | v2.9.0 | 8.84 | 0.07 | | +cross | 8.85 | 0.03 | | +jr | 8.83 | 0.06 | - NBench, arm-softmmu (debian jessie guest). Host: Intel i7-4790K @ 4.00GHz 1.3x +-+-------------------------------------------------------------------------------------------------------------+-+ | | | cross #### | 1.25x +cross+jr..........................................................#++#.........................................+-+ | #### # # | | +++# # # # | | +++ **** # # # | 1.2x +-+...................................####............*..*..#......#..#.........................................+-+ | **** # * * # # # #### | | * * # * * # # # # # | 1.15x +-+................................*..*..#............*..*..#......#..#.....#..#................................+-+ | * * # * * # # # # # | | * * # #### * * # # # # # | | * * # # # * * # # # # # #### | 1.1x +-+................................*..*..#......#..#..*..*..#......#..#.....#..#.........................#..#...+-+ | * * # # # * * # # # # # # # | | * * # # # * * # # # # # # # | 1.05x +-+..........................####..*..*..#......#..#..*..*..#......#..#.....#..#......+++............*****..#...+-+ | ***** # * * # # # * * # ***** # # # +++ | ****### * * # | | *+++* # * * # # # * * # *+++* # **** # *****### * * # * * # | | *****### +++#### * * # * * # ***** # * * # * * # * * # * | *++# * * # * * # | 1x +-++-+*+++*-+#++****++#++*+-+*++#+-*++*++#-+*+++*-+#++*++*++#++*+-+*++#+-*++*++#-+*+++*-+#++*++*++#++*+-+*++#+-++-+ | * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # | | * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # | 0.95x +-+---*****###--****###--*****###--****###--*****###--****###--*****###--****###--*****###--****###--*****###---+-+ ASSIGNMENT BITFIELD FOURFP EMULATION HUFFMAN LU DECOMPOSITIONEURAL NNUMERIC SOSTRING SORT hmean png: http://imgur.com/eOLmZNR NB. 'cross' represents the previous commit. Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <1493263764-18657-8-git-send-email-cota@braap.org> [rth: Replace gen_jr global variable with DISAS_EXIT state.] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-06-05target/arm: optimize cross-page direct jumps in softmmuEmilio G. Cota1-1/+5
Instead of unconditionally exiting to the exec loop, use the lookup_and_goto_ptr helper to jump to the target if it is valid. Perf impact: see next commit's log. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <1493263764-18657-7-git-send-email-cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-06-02arm: Implement HFNMIENA support for M profile MPUPeter Maydell1-0/+1
Implement HFNMIENA support for the M profile MPU. This bit controls whether the MPU is treated as enabled when executing at execution priorities of less than zero (in NMI, HardFault or with the FAULTMASK bit set). Doing this requires us to use a different MMU index for "running at execution priority < 0", because we will have different access permissions for that case versus the normal case. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1493122030-32191-14-git-send-email-peter.maydell@linaro.org
2017-06-02arm: Use different ARMMMUIdx values for M profilePeter Maydell1-0/+3
Make M profile use completely separate ARMMMUIdx values from those that A profile CPUs use. This is a prelude to adding support for the MPU and for v8M, which together will require 6 MMU indexes which don't map cleanly onto the A profile uses: non secure User non secure Privileged non secure Privileged, execution priority < 0 secure User secure Privileged secure Privileged, execution priority < 0 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1493122030-32191-4-git-send-email-peter.maydell@linaro.org
2017-06-02arm: Add support for M profile CPUs having different MMU index semanticsPeter Maydell1-5/+5
The M profile CPU's MPU has an awkward corner case which we would like to implement with a different MMU index. We can avoid having to bump the number of MMU modes ARM uses, because some of our existing MMU indexes are only used by non-M-profile CPUs, so we can borrow one. To avoid that getting too confusing, clean up the code to try to keep the two meanings of the index separate. Instead of ARMMMUIdx enum values being identical to core QEMU MMU index values, they are now the core index values with some high bits set. Any particular CPU always uses the same high bits (so eventually A profile cores and M profile cores will use different bits). New functions arm_to_core_mmu_idx() and core_to_arm_mmu_idx() convert between the two. In general core index values are stored in 'int' types, and ARM values are stored in ARMMMUIdx types. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1493122030-32191-3-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Remove workarounds for old M-profile exception return implementationPeter Maydell1-8/+0
Now that we've rewritten M-profile exception return so that the magic PC values are not visible to other parts of QEMU, we can delete the special casing of them elsewhere. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1491844419-12485-10-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Implement M profile exception return properlyPeter Maydell1-6/+60
On M profile, return from exceptions happen when code in Handler mode executes one of the following function call return instructions: * POP or LDM which loads the PC * LDR to PC * BX register and the new PC value is 0xFFxxxxxx. QEMU tries to implement this by not treating the instruction specially but then catching the attempt to execute from the magic address value. This is not ideal, because: * there are guest visible differences from the architecturally specified behaviour (for instance jumping to 0xFFxxxxxx via a different instruction should not cause an exception return but it will in the QEMU implementation) * we have to account for it in various places (like refusing to take an interrupt if the PC is at a magic value, and making sure that the MPU doesn't deny execution at the magic value addresses) Drop these hacks, and instead implement exception return the way the architecture specifies -- by having the relevant instructions check for the magic value and raise the 'do an exception return' QEMU internal exception immediately. The effect on the generated code is minor: bx lr, old code (and new code for Thread mode): TCG: mov_i32 tmp5,r14 movi_i32 tmp6,$0xfffffffffffffffe and_i32 pc,tmp5,tmp6 movi_i32 tmp6,$0x1 and_i32 tmp5,tmp5,tmp6 st_i32 tmp5,env,$0x218 exit_tb $0x0 set_label $L0 exit_tb $0x7f2aabd61993 x86_64 generated code: 0x7f2aabe87019: mov %ebx,%ebp 0x7f2aabe8701b: and $0xfffffffffffffffe,%ebp 0x7f2aabe8701e: mov %ebp,0x3c(%r14) 0x7f2aabe87022: and $0x1,%ebx 0x7f2aabe87025: mov %ebx,0x218(%r14) 0x7f2aabe8702c: xor %eax,%eax 0x7f2aabe8702e: jmpq 0x7f2aabe7c016 bx lr, new code when in Handler mode: TCG: mov_i32 tmp5,r14 movi_i32 tmp6,$0xfffffffffffffffe and_i32 pc,tmp5,tmp6 movi_i32 tmp6,$0x1 and_i32 tmp5,tmp5,tmp6 st_i32 tmp5,env,$0x218 movi_i32 tmp5,$0xffffffffff000000 brcond_i32 pc,tmp5,geu,$L1 exit_tb $0x0 set_label $L1 movi_i32 tmp5,$0x8 call exception_internal,$0x0,$0,env,tmp5 x86_64 generated code: 0x7fe8fa1264e3: mov %ebp,%ebx 0x7fe8fa1264e5: and $0xfffffffffffffffe,%ebx 0x7fe8fa1264e8: mov %ebx,0x3c(%r14) 0x7fe8fa1264ec: and $0x1,%ebp 0x7fe8fa1264ef: mov %ebp,0x218(%r14) 0x7fe8fa1264f6: cmp $0xff000000,%ebx 0x7fe8fa1264fc: jae 0x7fe8fa126509 0x7fe8fa126502: xor %eax,%eax 0x7fe8fa126504: jmpq 0x7fe8fa122016 0x7fe8fa126509: mov %r14,%rdi 0x7fe8fa12650c: mov $0x8,%esi 0x7fe8fa126511: mov $0x56095dbeccf5,%r10 0x7fe8fa12651b: callq *%r10 which is a difference of one cmp/branch-not-taken. This will be lost in the noise of having to exit generated code and look up the next TB anyway. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1491844419-12485-9-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Track M profile handler mode state in TB flagsPeter Maydell1-0/+1
For M profile exception-return handling we'd like to generate different code for some instructions depending on whether we are in Handler mode or Thread mode. This isn't the same as "are we privileged or user", so we need an extra bit in the TB flags to distinguish. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1491844419-12485-8-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Abstract out "are we singlestepping" test to utility functionPeter Maydell1-5/+15
We now test for "are we singlestepping" in several places and it's not a trivial check because we need to care about both architectural singlestep and QEMU gdbstub singlestep. We're also about to add another place that needs to make this check, so pull the condition out into a function. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1491844419-12485-7-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Move condition-failed codepath generation out of if()Peter Maydell1-13/+11
Move the code to generate the "condition failed" instruction codepath out of the if (singlestepping) {} else {}. This will allow adding support for handling a new is_jmp type which can't be neatly split into "singlestepping case" versus "not singlestepping case". Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1491844419-12485-6-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Move gen_set_condexec() and gen_set_pc_im() up in the filePeter Maydell1-16/+15
Move the utility routines gen_set_condexec() and gen_set_pc_im() up in the file, as we will want to use them from a function placed earlier in the file than their current location. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1491844419-12485-5-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Factor out "generate right kind of step exception"Peter Maydell1-12/+16
We currently have two places that do: if (dc->ss_active) { gen_step_complete_exception(dc); } else { gen_exception_internal(EXCP_DEBUG); } Factor this out into its own function, as we're about to add a third place that needs the same logic. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1491844419-12485-4-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Thumb shift operations should not permit interworking branchesPeter Maydell1-1/+1
In Thumb mode, the only instructions which can cause an interworking branch by writing the PC are BLX, BX, BXJ, LDR, POP and LDM. Unlike ARM mode, data processing instructions which target the PC do not cause interworking branches. When we added support for doing interworking branches on writes to PC from data processing instructions in commit 21aeb3430ce7ba, we accidentally changed a Thumb instruction to have interworking branch behaviour for writes to PC. (MOV, MOVS register-shifted register, encoding T2; this is the standard encoding for LSL/LSR/ASR/ROR (register).) For this encoding, behaviour with Rd == R15 is specified as UNPREDICTABLE, so allowing an interworking branch is within spec, but it's confusing and differs from our handling of this class of UNPREDICTABLE for other Thumb ALU operations. Make it perform a simple (non-interworking) branch like the others. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 1491844419-12485-3-git-send-email-peter.maydell@linaro.org
2017-04-20arm: Don't implement BXJ on M-profile CPUsPeter Maydell1-1/+6
For M-profile CPUs, the BXJ instruction does not exist at all, and the encoding should always UNDEF. We were accidentally implementing it to behave like A-profile BXJ; correct the error. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1491844419-12485-2-git-send-email-peter.maydell@linaro.org
2017-03-20arm: Fix APSR writes via M profile MSRPeter Maydell1-1/+2
Our implementation of writes to the APSR for M-profile via the MSR instruction was badly broken. First and worst, we had the sense wrong on the test of bit 2 of the SYSm field -- this is supposed to request an APSR write if bit 2 is 0 but we were doing it if bit 2 was 1. This bug was introduced in commit 58117c9bb429cd, so hasn't been in a QEMU release. Secondly, the choice of exactly which parts of APSR should be written is defined by bits in the 'mask' field. We were not passing these through from instruction decode, making it impossible to check them in the helper. Pass the mask bits through from the instruction decode to the helper function and process them appropriately; fix the wrong sense of the SYSm bit 2 check. Invalid mask values and invalid combinations of mask and register number are UNPREDICTABLE; we choose to treat them as if the mask values were valid. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1487616072-9226-5-git-send-email-peter.maydell@linaro.org Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-03-20arm: Enforce should-be-1 bits in MRS decodingPeter Maydell1-0/+14
The MRS instruction requires that bits [19..16] are all 1s, and for A/R profile also that bits [7..0] are all 0s. At this point in the decode tree we have checked all of the rest of the instruction but were allowing these to be any value. If these bits are not set then the result is architecturally UNPREDICTABLE, but choosing to UNDEF is more helpful to the user and avoids unexpected odd behaviour if the encodings are used for some purpose in future architecture versions. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 1487616072-9226-4-git-send-email-peter.maydell@linaro.org
2017-03-20arm: Don't decode MRS(banked) or MSR(banked) for M profilePeter Maydell1-2/+4
M profile doesn't have the MSR(banked) and MRS(banked) instructions and uses the encodings for different kinds of M-profile MRS/MSR. Guard the relevant bits of the decode logic to make sure we don't accidentally fall into them by accident on M-profile. (The bit being checked for this (bit 5) is part of the SYSm field on M-profile, but since no currently allocated system registers have encodings with bit 5 of SYSm set, this hasn't been a problem in practice.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 1487616072-9226-3-git-send-email-peter.maydell@linaro.org
2017-03-20arm: HVC and SMC encodings don't exist for M profilePeter Maydell1-0/+3
M profile doesn't have the HVC or SMC encodings, so make them always UNDEF rather than generating calls to helper functions that assume A/R profile. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 1487616072-9226-2-git-send-email-peter.maydell@linaro.org
2017-02-28armv7m: Raise correct kind of UsageFault for attempts to execute ARM codePeter Maydell1-2/+6
M profile doesn't implement ARM, and the architecturally required behaviour for attempts to execute with the Thumb bit clear is to generate a UsageFault with the CFSR INVSTATE bit set. We were incorrectly implementing this as generating an UNDEFINSTR UsageFault; fix this. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-24target-arm: don't generate WFE/YIELD calls for MTTCGAlex Bennée1-4/+16
The WFE and YIELD instructions are really only hints and in TCG's case they were useful to move the scheduling on from one vCPU to the next. In the parallel context (MTTCG) this just causes an unnecessary cpu_exit and contention of the BQL. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2017-02-07target/arm: A32, T32: Create Instruction Syndromes for Data AbortsPeter Maydell1-49/+135
Add support for generating the ISS (Instruction Specific Syndrome) for Data Abort exceptions taken from AArch32. These syndromes are used by hypervisors for example to trap and emulate memory accesses. This is the equivalent for AArch32 guests of the work done for AArch64 guests in commit aaa1f954d4cab243. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-02-07target/arm: Abstract out pbit/wbit tests in ARM ldr/str decodePeter Maydell1-3/+6
In the ARM ldr/str decode path, rather than directly testing "insn & (1 << 21)" and "insn & (1 << 24)", abstract these bits out into wbit and pbit local flags. (We will want to do more tests against them to determine whether we need to provide syndrome information.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-01-27armv7m: Report no-coprocessor faults correctlyPeter Maydell1-0/+8
For v7M attempts to access a nonexistent coprocessor are reported differently from plain undefined instructions (as UsageFaults of type NOCP rather than type UNDEFINSTR). Split them out into a new EXCP_NOCP so we can report the FSR value correctly. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 1485285380-10565-8-git-send-email-peter.maydell@linaro.org
2017-01-27armv7m: Replace armv7m.hack with unassigned_access handlerMichael Davidsaver1-6/+6
For v7m we need to catch attempts to execute from special addresses at 0xfffffff0 and above. Previously we did this with the aid of a hacky special purpose lump of memory in the address space and a check in translate.c for whether we were translating code at those addresses. We can implement this more cleanly using a CPU unassigned access handler which throws the exception if the unassigned access is for one of the special addresses. Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 1484937883-1068-3-git-send-email-peter.maydell@linaro.org [PMM: * drop the deletion of the "don't interrupt if PC is magic" code in arm_v7m_cpu_exec_interrupt() -- this is still required * don't generate an exception for unassigned accesses which aren't to the magic address -- although doing this is in theory correct in practice it will break currently working guests which rely on the RAZ/WI behaviour when they touch devices which we haven't modelled. * trigger EXCP_EXCEPTION_EXIT on is_exec, not !is_write ] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-10target-arm: Use clz opcodeRichard Henderson1-3/+3
Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-01-10target-arm: Use new deposit and extract opsRichard Henderson1-29/+8
Use the new primitives for UBFX and SBFX. Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-12-20Move target-* CPU file into a target/ folderThomas Huth1-0/+12055
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>
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