rtc: Move RTC function prototypes to their own header

softmmu/rtc.c defines two public functions: qemu_get_timedate() and
qemu_timedate_diff().  Currently we keep the prototypes for these in
qemu-common.h, but most files don't need them.  Move them to their
own header, a new include/sysemu/rtc.h.

Since the C files using these two functions did not need to include
qemu-common.h for any other reason, we can remove those include lines
when we add the include of the new rtc.h.

The license for the .h file follows that of the softmmu/rtc.c
where both the functions are defined.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/arm/omap1.c

@@ -21,7 +21,6 @@
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qapi/error.h"
-#include "qemu-common.h"
 #include "cpu.h"
 #include "exec/address-spaces.h"
 #include "hw/hw.h"
@@ -35,6 +34,7 @@
 #include "sysemu/qtest.h"
 #include "sysemu/reset.h"
 #include "sysemu/runstate.h"
+#include "sysemu/rtc.h"
 #include "qemu/range.h"
 #include "hw/sysbus.h"
 #include "qemu/cutils.h"

hw/arm/pxa2xx.c

@@ -8,7 +8,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
@@ -27,6 +26,7 @@
 #include "chardev/char-fe.h"
 #include "sysemu/blockdev.h"
 #include "sysemu/qtest.h"
+#include "sysemu/rtc.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"
 #include "qom/object.h"

hw/arm/strongarm.c

@@ -28,7 +28,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "cpu.h"
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
@@ -41,6 +40,7 @@
 #include "chardev/char-fe.h"
 #include "chardev/char-serial.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 #include "hw/ssi/ssi.h"
 #include "qapi/error.h"
 #include "qemu/cutils.h"

hw/misc/mac_via.c

@@ -16,7 +16,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "migration/vmstate.h"
 #include "hw/sysbus.h"
 #include "hw/irq.h"
@@ -30,6 +29,7 @@
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/rtc.h"
 #include "trace.h"
 #include "qemu/log.h"
 

hw/misc/macio/cuda.c

@@ -24,7 +24,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/ppc/mac.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
@@ -34,6 +33,7 @@
 #include "qapi/error.h"
 #include "qemu/timer.h"
 #include "sysemu/runstate.h"
+#include "sysemu/rtc.h"
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"

hw/misc/macio/pmu.c

@@ -29,7 +29,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/ppc/mac.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
@@ -41,6 +40,7 @@
 #include "qapi/error.h"
 #include "qemu/timer.h"
 #include "sysemu/runstate.h"
+#include "sysemu/rtc.h"
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"

hw/ppc/spapr_rtc.c

@@ -26,9 +26,9 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 #include "hw/ppc/spapr.h"
 #include "migration/vmstate.h"
 #include "qapi/error.h"

hw/rtc/allwinner-rtc.c

@@ -23,9 +23,9 @@
 #include "migration/vmstate.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
-#include "qemu-common.h"
 #include "hw/qdev-properties.h"
 #include "hw/rtc/allwinner-rtc.h"
+#include "sysemu/rtc.h"
 #include "trace.h"
 
 /* RTC registers */

hw/rtc/aspeed_rtc.c

@@ -7,11 +7,11 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/rtc/aspeed_rtc.h"
 #include "migration/vmstate.h"
 #include "qemu/log.h"
 #include "qemu/timer.h"
+#include "sysemu/rtc.h"
 
 #include "trace.h"
 

hw/rtc/ds1338.c

@@ -11,12 +11,12 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/i2c/i2c.h"
 #include "migration/vmstate.h"
 #include "qemu/bcd.h"
 #include "qemu/module.h"
 #include "qom/object.h"
+#include "sysemu/rtc.h"
 
 /* Size of NVRAM including both the user-accessible area and the
  * secondary register area.

hw/rtc/exynos4210_rtc.c

@@ -26,7 +26,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 #include "hw/sysbus.h"
@@ -39,6 +38,7 @@
 
 #include "hw/arm/exynos4210.h"
 #include "qom/object.h"
+#include "sysemu/rtc.h"
 
 #define DEBUG_RTC 0
 

hw/rtc/goldfish_rtc.c

@@ -20,7 +20,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/rtc/goldfish_rtc.h"
 #include "migration/vmstate.h"
 #include "hw/irq.h"
@@ -29,6 +28,7 @@
 #include "qemu/bitops.h"
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"
 

hw/rtc/m41t80.c

@@ -8,13 +8,13 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 #include "qemu/timer.h"
 #include "qemu/bcd.h"
 #include "hw/i2c/i2c.h"
 #include "qom/object.h"
+#include "sysemu/rtc.h"
 
 #define TYPE_M41T80 "m41t80"
 OBJECT_DECLARE_SIMPLE_TYPE(M41t80State, M41T80)

hw/rtc/m48t59.c

@@ -24,12 +24,12 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
 #include "hw/rtc/m48t59.h"
 #include "qemu/timer.h"
 #include "sysemu/runstate.h"
+#include "sysemu/rtc.h"
 #include "sysemu/sysemu.h"
 #include "hw/sysbus.h"
 #include "qapi/error.h"

hw/rtc/mc146818rtc.c

@@ -23,7 +23,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/cutils.h"
 #include "qemu/module.h"
 #include "qemu/bcd.h"
@@ -36,6 +35,7 @@
 #include "sysemu/replay.h"
 #include "sysemu/reset.h"
 #include "sysemu/runstate.h"
+#include "sysemu/rtc.h"
 #include "hw/rtc/mc146818rtc.h"
 #include "hw/rtc/mc146818rtc_regs.h"
 #include "migration/vmstate.h"

hw/rtc/pl031.c

@@ -12,7 +12,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/rtc/pl031.h"
 #include "migration/vmstate.h"
 #include "hw/irq.h"
@@ -20,6 +19,7 @@
 #include "hw/sysbus.h"
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"
 #include "qemu/module.h"

hw/rtc/twl92230.c

@@ -20,13 +20,13 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/timer.h"
 #include "hw/i2c/i2c.h"
 #include "hw/irq.h"
 #include "migration/qemu-file-types.h"
 #include "migration/vmstate.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 #include "qemu/bcd.h"
 #include "qemu/module.h"
 #include "qom/object.h"

hw/rtc/xlnx-zynqmp-rtc.c

@@ -25,7 +25,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/sysbus.h"
 #include "hw/register.h"
 #include "qemu/bitops.h"
@@ -34,6 +33,7 @@
 #include "hw/irq.h"
 #include "qemu/cutils.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 #include "trace.h"
 #include "hw/rtc/xlnx-zynqmp-rtc.h"
 #include "migration/vmstate.h"

hw/s390x/tod-tcg.c

@@ -9,7 +9,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qapi/error.h"
 #include "hw/s390x/tod.h"
 #include "qemu/timer.h"
@@ -17,6 +16,7 @@
 #include "qemu/module.h"
 #include "cpu.h"
 #include "tcg/tcg_s390x.h"
+#include "sysemu/rtc.h"
 
 static void qemu_s390_tod_get(const S390TODState *td, S390TOD *tod,
                               Error **errp)

hw/scsi/megasas.c

@@ -19,11 +19,11 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "hw/pci/pci.h"
 #include "hw/qdev-properties.h"
 #include "sysemu/dma.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/rtc.h"
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
 #include "qemu/iov.h"

include/qemu-common.h

@@ -26,9 +26,6 @@
 int qemu_main(int argc, char **argv, char **envp);
 #endif
 
-void qemu_get_timedate(struct tm *tm, int offset);
-int qemu_timedate_diff(struct tm *tm);
-
 void *qemu_oom_check(void *ptr);
 
 ssize_t qemu_write_full(int fd, const void *buf, size_t count)

include/sysemu/rtc.h

@@ -0,0 +1,58 @@
+/*
+ * RTC configuration and clock read
+ *
+ * Copyright (c) 2003-2021 QEMU contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef SYSEMU_RTC_H
+#define SYSEMU_RTC_H
+
+/**
+ * qemu_get_timedate: Get the current RTC time
+ * @tm: struct tm to fill in with RTC time
+ * @offset: offset in seconds to adjust the RTC time by before
+ *          converting to struct tm format.
+ *
+ * This function fills in @tm with the current RTC time, as adjusted
+ * by @offset (for example, if @offset is 3600 then the returned time/date
+ * will be one hour further ahead than the current RTC time).
+ *
+ * The usual use is by RTC device models, which should call this function
+ * to find the time/date value that they should return to the guest
+ * when it reads the RTC registers.
+ *
+ * The behaviour of the clock whose value this function returns will
+ * depend on the -rtc command line option passed by the user.
+ */
+void qemu_get_timedate(struct tm *tm, int offset);
+
+/**
+ * qemu_timedate_diff: Return difference between a struct tm and the RTC
+ * @tm: struct tm containing the date/time to compare against
+ *
+ * Returns the difference in seconds between the RTC clock time
+ * and the date/time specified in @tm. For example, if @tm specifies
+ * a timestamp one hour further ahead than the current RTC time
+ * then this function will return 3600.
+ */
+int qemu_timedate_diff(struct tm *tm);
+
+#endif

net/dump.c

@@ -23,7 +23,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "clients.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
@@ -33,6 +32,7 @@
 #include "qapi/visitor.h"
 #include "net/filter.h"
 #include "qom/object.h"
+#include "sysemu/rtc.h"
 
 typedef struct DumpState {
     int64_t start_ts;

softmmu/rtc.c

@@ -23,7 +23,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
@@ -33,6 +32,7 @@
 #include "qom/object.h"
 #include "sysemu/replay.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/rtc.h"
 
 static enum {
     RTC_BASE_UTC,