From 52e60cdd342dc48116edb81b443ba8c0a0c6f1a3 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Tue, 15 Apr 2014 19:18:44 +0100 Subject: target-arm: Implement AArch64 EL1 exception handling Implement exception handling for AArch64 EL1. Exceptions from AArch64 or AArch32 EL0 are supported. Signed-off-by: Rob Herring [PMM: fixed minor style nits; updated to match changes in previous patches; added some of the simpler cases of illegal-exception-return support] Signed-off-by: Peter Maydell Reviewed-by: Peter Crosthwaite --- target-arm/cpu-qom.h | 2 ++ target-arm/cpu64.c | 1 + target-arm/helper-a64.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++ target-arm/helper.h | 1 + target-arm/op_helper.c | 60 ++++++++++++++++++++++++++++++++++++ target-arm/translate-a64.c | 3 ++ 6 files changed, 143 insertions(+) diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h index 41caa6c..afdee9d 100644 --- a/target-arm/cpu-qom.h +++ b/target-arm/cpu-qom.h @@ -202,6 +202,8 @@ void aarch64_cpu_dump_state(CPUState *cs, FILE *f, fprintf_function cpu_fprintf, int flags); int aarch64_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg); int aarch64_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg); + +void aarch64_cpu_do_interrupt(CPUState *cs); #endif #endif diff --git a/target-arm/cpu64.c b/target-arm/cpu64.c index fccecc2..d4fb1de 100644 --- a/target-arm/cpu64.c +++ b/target-arm/cpu64.c @@ -85,6 +85,7 @@ static void aarch64_cpu_class_init(ObjectClass *oc, void *data) { CPUClass *cc = CPU_CLASS(oc); + cc->do_interrupt = aarch64_cpu_do_interrupt; cc->dump_state = aarch64_cpu_dump_state; cc->set_pc = aarch64_cpu_set_pc; cc->gdb_read_register = aarch64_cpu_gdb_read_register; diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c index ec02582..bf921cc 100644 --- a/target-arm/helper-a64.c +++ b/target-arm/helper-a64.c @@ -23,6 +23,7 @@ #include "qemu/host-utils.h" #include "sysemu/sysemu.h" #include "qemu/bitops.h" +#include "internals.h" /* C2.4.7 Multiply and divide */ /* special cases for 0 and LLONG_MIN are mandated by the standard */ @@ -436,3 +437,78 @@ float32 HELPER(fcvtx_f64_to_f32)(float64 a, CPUARMState *env) set_float_exception_flags(exflags, fpst); return r; } + +/* Handle a CPU exception. */ +void aarch64_cpu_do_interrupt(CPUState *cs) +{ + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + target_ulong addr = env->cp15.c12_vbar; + int i; + + if (arm_current_pl(env) == 0) { + if (env->aarch64) { + addr += 0x400; + } else { + addr += 0x600; + } + } else if (pstate_read(env) & PSTATE_SP) { + addr += 0x200; + } + + arm_log_exception(cs->exception_index); + qemu_log_mask(CPU_LOG_INT, "...from EL%d\n", arm_current_pl(env)); + if (qemu_loglevel_mask(CPU_LOG_INT) + && !excp_is_internal(cs->exception_index)) { + qemu_log_mask(CPU_LOG_INT, "...with ESR 0x%" PRIx32 "\n", + env->exception.syndrome); + } + + env->cp15.esr_el1 = env->exception.syndrome; + env->cp15.far_el1 = env->exception.vaddress; + + switch (cs->exception_index) { + case EXCP_PREFETCH_ABORT: + case EXCP_DATA_ABORT: + qemu_log_mask(CPU_LOG_INT, "...with FAR 0x%" PRIx64 "\n", + env->cp15.far_el1); + break; + case EXCP_BKPT: + case EXCP_UDEF: + case EXCP_SWI: + break; + case EXCP_IRQ: + addr += 0x80; + break; + case EXCP_FIQ: + addr += 0x100; + break; + default: + cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index); + } + + if (is_a64(env)) { + env->banked_spsr[0] = pstate_read(env); + env->sp_el[arm_current_pl(env)] = env->xregs[31]; + env->xregs[31] = env->sp_el[1]; + env->elr_el1 = env->pc; + } else { + env->banked_spsr[0] = cpsr_read(env); + if (!env->thumb) { + env->cp15.esr_el1 |= 1 << 25; + } + env->elr_el1 = env->regs[15]; + + for (i = 0; i < 15; i++) { + env->xregs[i] = env->regs[i]; + } + + env->condexec_bits = 0; + } + + pstate_write(env, PSTATE_DAIF | PSTATE_MODE_EL1h); + env->aarch64 = 1; + + env->pc = addr; + cs->interrupt_request |= CPU_INTERRUPT_EXITTB; +} diff --git a/target-arm/helper.h b/target-arm/helper.h index 5977169..a5449e7 100644 --- a/target-arm/helper.h +++ b/target-arm/helper.h @@ -66,6 +66,7 @@ DEF_HELPER_3(set_cp_reg64, void, env, ptr, i64) DEF_HELPER_2(get_cp_reg64, i64, env, ptr) DEF_HELPER_3(msr_i_pstate, void, env, i32, i32) +DEF_HELPER_1(exception_return, void, env) DEF_HELPER_2(get_r13_banked, i32, env, i32) DEF_HELPER_3(set_r13_banked, void, env, i32, i32) diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c index 64a33dd..57e7d9c 100644 --- a/target-arm/op_helper.c +++ b/target-arm/op_helper.c @@ -384,6 +384,66 @@ void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm) } } +void HELPER(exception_return)(CPUARMState *env) +{ + uint32_t spsr = env->banked_spsr[0]; + int new_el, i; + + if (env->pstate & PSTATE_SP) { + env->sp_el[1] = env->xregs[31]; + } else { + env->sp_el[0] = env->xregs[31]; + } + + env->exclusive_addr = -1; + + if (spsr & PSTATE_nRW) { + env->aarch64 = 0; + new_el = 0; + env->uncached_cpsr = 0x10; + cpsr_write(env, spsr, ~0); + for (i = 0; i < 15; i++) { + env->regs[i] = env->xregs[i]; + } + + env->regs[15] = env->elr_el1 & ~0x1; + } else { + new_el = extract32(spsr, 2, 2); + if (new_el > 1) { + /* Return to unimplemented EL */ + goto illegal_return; + } + if (extract32(spsr, 1, 1)) { + /* Return with reserved M[1] bit set */ + goto illegal_return; + } + if (new_el == 0 && (spsr & PSTATE_SP)) { + /* Return to EL1 with M[0] bit set */ + goto illegal_return; + } + env->aarch64 = 1; + pstate_write(env, spsr); + env->xregs[31] = env->sp_el[new_el]; + env->pc = env->elr_el1; + } + + return; + +illegal_return: + /* Illegal return events of various kinds have architecturally + * mandated behaviour: + * restore NZCV and DAIF from SPSR_ELx + * set PSTATE.IL + * restore PC from ELR_ELx + * no change to exception level, execution state or stack pointer + */ + env->pstate |= PSTATE_IL; + env->pc = env->elr_el1; + spsr &= PSTATE_NZCV | PSTATE_DAIF; + spsr |= pstate_read(env) & ~(PSTATE_NZCV | PSTATE_DAIF); + pstate_write(env, spsr); +} + /* ??? Flag setting arithmetic is awkward because we need to do comparisons. The only way to do that in TCG is a conditional branch, which clobbers all our temporaries. For now implement these as helper functions. */ diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 4c5402a..188287d 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -1512,6 +1512,9 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn) tcg_gen_movi_i64(cpu_reg(s, 30), s->pc); break; case 4: /* ERET */ + gen_helper_exception_return(cpu_env); + s->is_jmp = DISAS_JUMP; + return; case 5: /* DRPS */ if (rn != 0x1f) { unallocated_encoding(s); -- cgit v1.1