[PATCH 01/16] hw/core/cpu: Let CPU object have a clock source

[Philippe Mathieu-Daudé]

Let CPUState have a clock source (named 'clk') and CPUClass
have a clock_update() callback. The clock can be optionally
set Using qdev_connect_clock_in() from the Clock API.
If the clock changes, the optional clock_update() will be
called.

Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
---
 include/hw/core/cpu.h |  5 +++++
 hw/core/cpu.c         | 12 ++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 6c34798c8b3..6989d90c193 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -31,6 +31,7 @@
 #include "qemu/thread.h"
 #include "qemu/plugin.h"
 #include "qom/object.h"
+#include "hw/clock.h"
 
 typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,
                                      void *opaque);
@@ -155,6 +156,7 @@ struct TranslationBlock;
  * @disas_set_info: Setup architecture specific components of disassembly info
  * @adjust_watchpoint_address: Perform a target-specific adjustment to an
  * address before attempting to match it against watchpoints.
+ * @clock_update: Callback for input clock changes
  *
  * Represents a CPU family or model.
  */
@@ -176,6 +178,7 @@ struct CPUClass {
                                   unsigned size, MMUAccessType access_type,
                                   int mmu_idx, MemTxAttrs attrs,
                                   MemTxResult response, uintptr_t retaddr);
+    void (*clock_update)(CPUState *cpu);
     bool (*virtio_is_big_endian)(CPUState *cpu);
     int (*memory_rw_debug)(CPUState *cpu, vaddr addr,
                            uint8_t *buf, int len, bool is_write);
@@ -316,6 +319,7 @@ struct qemu_work_item;
  *   QOM parent.
  * @nr_cores: Number of cores within this CPU package.
  * @nr_threads: Number of threads within this CPU.
+ * @clock: this CPU source clock (an output clock of another device)
  * @running: #true if CPU is currently running (lockless).
  * @has_waiter: #true if a CPU is currently waiting for the cpu_exec_end;
  * valid under cpu_list_lock.
@@ -400,6 +404,7 @@ struct CPUState {
     int num_ases;
     AddressSpace *as;
     MemoryRegion *memory;
+    Clock *clock;
 
     void *env_ptr; /* CPUArchState */
     IcountDecr *icount_decr_ptr;
diff --git a/hw/core/cpu.c b/hw/core/cpu.c
index c55c09f734c..37fcff3ec64 100644
--- a/hw/core/cpu.c
+++ b/hw/core/cpu.c
@@ -30,6 +30,7 @@
 #include "qemu/qemu-print.h"
 #include "sysemu/tcg.h"
 #include "hw/boards.h"
+#include "hw/qdev-clock.h"
 #include "hw/qdev-properties.h"
 #include "trace/trace-root.h"
 #include "qemu/plugin.h"
@@ -247,6 +248,16 @@ void cpu_reset(CPUState *cpu)
     trace_guest_cpu_reset(cpu);
 }
 
+static void cpu_clk_update(void *opaque)
+{
+    CPUState *cpu = opaque;
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
+    if (cc->clock_update) {
+        cc->clock_update(cpu);
+    }
+}
+
 static void cpu_common_reset(DeviceState *dev)
 {
     CPUState *cpu = CPU(dev);
@@ -367,6 +378,7 @@ static void cpu_common_initfn(Object *obj)
     /* the default value is changed by qemu_init_vcpu() for softmmu */
     cpu->nr_cores = 1;
     cpu->nr_threads = 1;
+    cpu->clock = qdev_init_clock_in(DEVICE(obj), "clk", cpu_clk_update, cpu);
 
     qemu_mutex_init(&cpu->work_mutex);
     QSIMPLEQ_INIT(&cpu->work_list);
-- 
2.26.2