[PATCH v3 06/10] introduce cpu_test_interrupt() that will replace open coded checks

[Igor Mammedov <imammedo@redhat.com>]

the helper forms load-acquire/store-release pair with
tcg_handle_interrupt/generic_handle_interrupt and can be used
for checking interrupts outside of BQL

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 include/hw/core/cpu.h     | 12 ++++++++++++
 accel/tcg/tcg-accel-ops.c |  3 ++-
 system/cpus.c             |  3 ++-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 5eaf41a566..d0460c01cf 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -942,6 +942,18 @@ CPUState *cpu_by_arch_id(int64_t id);
 
 void cpu_interrupt(CPUState *cpu, int mask);
 
+/**
+ * cpu_test_interrupt:
+ * @cpu: The CPU to check interrupt(s) on.
+ * @mask: The interrupts to check.
+ *
+ * Checks if any of interrupts in @mask are pending on @cpu.
+ */
+static inline bool cpu_test_interrupt(CPUState *cpu, int mask)
+{
+    return qatomic_load_acquire(&cpu->interrupt_request) & mask;
+}
+
 /**
  * cpu_set_pc:
  * @cpu: The CPU to set the program counter for.
diff --git a/accel/tcg/tcg-accel-ops.c b/accel/tcg/tcg-accel-ops.c
index 3b0d7d298e..02c7600bb7 100644
--- a/accel/tcg/tcg-accel-ops.c
+++ b/accel/tcg/tcg-accel-ops.c
@@ -97,7 +97,8 @@ static void tcg_cpu_reset_hold(CPUState *cpu)
 /* mask must never be zero, except for A20 change call */
 void tcg_handle_interrupt(CPUState *cpu, int mask)
 {
-    cpu->interrupt_request |= mask;
+    qatomic_store_release(&cpu->interrupt_request,
+        cpu->interrupt_request | mask);
 
     /*
      * If called from iothread context, wake the target cpu in
diff --git a/system/cpus.c b/system/cpus.c
index 256723558d..8e543488c3 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -256,7 +256,8 @@ int64_t cpus_get_elapsed_ticks(void)
 
 void generic_handle_interrupt(CPUState *cpu, int mask)
 {
-    cpu->interrupt_request |= mask;
+    qatomic_store_release(&cpu->interrupt_request,
+        cpu->interrupt_request | mask);
 
     if (!qemu_cpu_is_self(cpu)) {
         qemu_cpu_kick(cpu);
-- 
2.47.1