target-arm: Move aarch64_cpu_do_interrupt() to helper.c

Move the aarch64_cpu_do_interrupt() function to helper.c. We want
to be able to call this from code that isn't AArch64-only, and
the move allows us to avoid awkward #ifdeffery at the callsite.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 6c5dcfd..573e155 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -12,6 +12,7 @@
 #include "arm_ldst.h"
 #include <zlib.h> /* For crc32 */
 #include "exec/semihost.h"
+#include "sysemu/kvm.h"
 
 #define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */
 
@@ -5902,6 +5903,105 @@
     cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
 }
 
+/* Handle a CPU exception.  */
+void aarch64_cpu_do_interrupt(CPUState *cs)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    CPUARMState *env = &cpu->env;
+    unsigned int new_el = env->exception.target_el;
+    target_ulong addr = env->cp15.vbar_el[new_el];
+    unsigned int new_mode = aarch64_pstate_mode(new_el, true);
+
+    if (arm_current_el(env) < new_el) {
+        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 to EL%d\n", arm_current_el(env),
+                  new_el);
+    if (qemu_loglevel_mask(CPU_LOG_INT)
+        && !excp_is_internal(cs->exception_index)) {
+        qemu_log_mask(CPU_LOG_INT, "...with ESR %x/0x%" PRIx32 "\n",
+                      env->exception.syndrome >> ARM_EL_EC_SHIFT,
+                      env->exception.syndrome);
+    }
+
+    if (arm_is_psci_call(cpu, cs->exception_index)) {
+        arm_handle_psci_call(cpu);
+        qemu_log_mask(CPU_LOG_INT, "...handled as PSCI call\n");
+        return;
+    }
+
+    switch (cs->exception_index) {
+    case EXCP_PREFETCH_ABORT:
+    case EXCP_DATA_ABORT:
+        env->cp15.far_el[new_el] = env->exception.vaddress;
+        qemu_log_mask(CPU_LOG_INT, "...with FAR 0x%" PRIx64 "\n",
+                      env->cp15.far_el[new_el]);
+        /* fall through */
+    case EXCP_BKPT:
+    case EXCP_UDEF:
+    case EXCP_SWI:
+    case EXCP_HVC:
+    case EXCP_HYP_TRAP:
+    case EXCP_SMC:
+        env->cp15.esr_el[new_el] = env->exception.syndrome;
+        break;
+    case EXCP_IRQ:
+    case EXCP_VIRQ:
+        addr += 0x80;
+        break;
+    case EXCP_FIQ:
+    case EXCP_VFIQ:
+        addr += 0x100;
+        break;
+    case EXCP_SEMIHOST:
+        qemu_log_mask(CPU_LOG_INT,
+                      "...handling as semihosting call 0x%" PRIx64 "\n",
+                      env->xregs[0]);
+        env->xregs[0] = do_arm_semihosting(env);
+        return;
+    default:
+        cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
+    }
+
+    if (is_a64(env)) {
+        env->banked_spsr[aarch64_banked_spsr_index(new_el)] = pstate_read(env);
+        aarch64_save_sp(env, arm_current_el(env));
+        env->elr_el[new_el] = env->pc;
+    } else {
+        env->banked_spsr[aarch64_banked_spsr_index(new_el)] = cpsr_read(env);
+        if (!env->thumb) {
+            env->cp15.esr_el[new_el] |= 1 << 25;
+        }
+        env->elr_el[new_el] = env->regs[15];
+
+        aarch64_sync_32_to_64(env);
+
+        env->condexec_bits = 0;
+    }
+    qemu_log_mask(CPU_LOG_INT, "...with ELR 0x%" PRIx64 "\n",
+                  env->elr_el[new_el]);
+
+    pstate_write(env, PSTATE_DAIF | new_mode);
+    env->aarch64 = 1;
+    aarch64_restore_sp(env, new_el);
+
+    env->pc = addr;
+
+    qemu_log_mask(CPU_LOG_INT, "...to EL%d PC 0x%" PRIx64 " PSTATE 0x%x\n",
+                  new_el, env->pc, pstate_read(env));
+
+    if (!kvm_enabled()) {
+        cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
+    }
+}
 
 /* Return the exception level which controls this address translation regime */
 static inline uint32_t regime_el(CPUARMState *env, ARMMMUIdx mmu_idx)