target/ppc: introduce ppc_maybe_interrupt

This new method will check if any pending interrupt was unmasked and
then call cpu_interrupt/cpu_reset_interrupt accordingly. Code that
raises/lowers or masks/unmasks interrupts should call this method to
keep CPU_INTERRUPT_HARD coherent with env->pending_interrupts.

Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20221021142156.4134411-2-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 14bec2490f..07480079f7 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -390,6 +390,7 @@ static void powerpc_set_excp_state(PowerPCCPU *cpu, target_ulong vector,
     env->nip = vector;
     env->msr = msr;
     hreg_compute_hflags(env);
+    ppc_maybe_interrupt(env);
 
     powerpc_reset_excp_state(cpu);
 
@@ -2044,6 +2045,40 @@ static int ppc_next_unmasked_interrupt(CPUPPCState *env)
     }
 }
 
+/*
+ * Sets CPU_INTERRUPT_HARD if there is at least one unmasked interrupt to be
+ * delivered and clears CPU_INTERRUPT_HARD otherwise.
+ *
+ * This method is called by ppc_set_interrupt when an interrupt is raised or
+ * lowered, and should also be called whenever an interrupt masking condition
+ * is changed, e.g.:
+ *  - When relevant bits of MSR are altered, like EE, HV, PR, etc.;
+ *  - When relevant bits of LPCR are altered, like PECE, HDICE, HVICE, etc.;
+ *  - When PSSCR[EC] or env->resume_as_sreset are changed;
+ *  - When cs->halted is changed and the CPU has a different interrupt masking
+ *    logic in power-saving mode (e.g., POWER7/8/9/10);
+ */
+void ppc_maybe_interrupt(CPUPPCState *env)
+{
+    CPUState *cs = env_cpu(env);
+    bool locked = false;
+
+    if (!qemu_mutex_iothread_locked()) {
+        locked = true;
+        qemu_mutex_lock_iothread();
+    }
+
+    if (ppc_next_unmasked_interrupt(env)) {
+        cpu_interrupt(cs, CPU_INTERRUPT_HARD);
+    } else {
+        cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
+    }
+
+    if (locked) {
+        qemu_mutex_unlock_iothread();
+    }
+}
+
 #if defined(TARGET_PPC64)
 static void p7_deliver_interrupt(CPUPPCState *env, int interrupt)
 {
@@ -2479,6 +2514,11 @@ void helper_store_msr(CPUPPCState *env, target_ulong val)
     }
 }
 
+void helper_ppc_maybe_interrupt(CPUPPCState *env)
+{
+    ppc_maybe_interrupt(env);
+}
+
 #if defined(TARGET_PPC64)
 void helper_scv(CPUPPCState *env, uint32_t lev)
 {
@@ -2499,6 +2539,8 @@ void helper_pminsn(CPUPPCState *env, powerpc_pm_insn_t insn)
     /* Condition for waking up at 0x100 */
     env->resume_as_sreset = (insn != PPC_PM_STOP) ||
         (env->spr[SPR_PSSCR] & PSSCR_EC);
+
+    ppc_maybe_interrupt(env);
 }
 #endif /* defined(TARGET_PPC64) */