rtc: Move RTC function prototypes to their own header

[PATCH for-7.0] rtc: Move RTC function prototypes to their own header

Posted by Peter Maydell 2 years, 4 months ago

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>
---
I have added documentation comments for the two functions, but
since my understanding of them and their purpose is little shaky
review would be welcome.
---
 include/qemu-common.h    |  3 ---
 include/sysemu/rtc.h     | 58 ++++++++++++++++++++++++++++++++++++++++
 hw/arm/omap1.c           |  2 +-
 hw/arm/pxa2xx.c          |  2 +-
 hw/arm/strongarm.c       |  2 +-
 hw/misc/mac_via.c        |  2 +-
 hw/misc/macio/cuda.c     |  2 +-
 hw/misc/macio/pmu.c      |  2 +-
 hw/ppc/spapr_rtc.c       |  2 +-
 hw/rtc/allwinner-rtc.c   |  2 +-
 hw/rtc/aspeed_rtc.c      |  2 +-
 hw/rtc/ds1338.c          |  2 +-
 hw/rtc/exynos4210_rtc.c  |  2 +-
 hw/rtc/goldfish_rtc.c    |  2 +-
 hw/rtc/m41t80.c          |  2 +-
 hw/rtc/m48t59.c          |  2 +-
 hw/rtc/mc146818rtc.c     |  2 +-
 hw/rtc/pl031.c           |  2 +-
 hw/rtc/twl92230.c        |  2 +-
 hw/rtc/xlnx-zynqmp-rtc.c |  2 +-
 hw/s390x/tod-tcg.c       |  2 +-
 hw/scsi/megasas.c        |  2 +-
 net/dump.c               |  2 +-
 softmmu/rtc.c            |  2 +-
 24 files changed, 80 insertions(+), 25 deletions(-)
 create mode 100644 include/sysemu/rtc.h

diff --git a/include/qemu-common.h b/include/qemu-common.h
index 73bcf763ed8..bed0b06a3d2 100644
--- a/include/qemu-common.h
+++ b/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)
diff --git a/include/sysemu/rtc.h b/include/sysemu/rtc.h
new file mode 100644
index 00000000000..159702b45b5
--- /dev/null
+++ b/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
diff --git a/hw/arm/omap1.c b/hw/arm/omap1.c
index 180d3788f89..9852c2a07ec 100644
--- a/hw/arm/omap1.c
+++ b/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"
diff --git a/hw/arm/pxa2xx.c b/hw/arm/pxa2xx.c
index 15a247efae2..a6f938f1152 100644
--- a/hw/arm/pxa2xx.c
+++ b/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"
diff --git a/hw/arm/strongarm.c b/hw/arm/strongarm.c
index 939a57dda55..39b8f01ac48 100644
--- a/hw/arm/strongarm.c
+++ b/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"
diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
index b378e6b3055..71b74c33721 100644
--- a/hw/misc/mac_via.c
+++ b/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"
 
diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
index e917a6a095b..233daf1405f 100644
--- a/hw/misc/macio/cuda.c
+++ b/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"
diff --git a/hw/misc/macio/pmu.c b/hw/misc/macio/pmu.c
index eb39c64694a..76c608ee19d 100644
--- a/hw/misc/macio/pmu.c
+++ b/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"
diff --git a/hw/ppc/spapr_rtc.c b/hw/ppc/spapr_rtc.c
index fba4dfca358..94a5510e4eb 100644
--- a/hw/ppc/spapr_rtc.c
+++ b/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"
diff --git a/hw/rtc/allwinner-rtc.c b/hw/rtc/allwinner-rtc.c
index 5606a51d5c5..7e493f0e79d 100644
--- a/hw/rtc/allwinner-rtc.c
+++ b/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 */
diff --git a/hw/rtc/aspeed_rtc.c b/hw/rtc/aspeed_rtc.c
index 3ca1183558b..f6da7b666d6 100644
--- a/hw/rtc/aspeed_rtc.c
+++ b/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"
 
diff --git a/hw/rtc/ds1338.c b/hw/rtc/ds1338.c
index bc5ce1a9f46..36d8121ddda 100644
--- a/hw/rtc/ds1338.c
+++ b/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.
diff --git a/hw/rtc/exynos4210_rtc.c b/hw/rtc/exynos4210_rtc.c
index 45c0a951c44..ae67641de66 100644
--- a/hw/rtc/exynos4210_rtc.c
+++ b/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
 
diff --git a/hw/rtc/goldfish_rtc.c b/hw/rtc/goldfish_rtc.c
index e07ff0164e0..35e493be312 100644
--- a/hw/rtc/goldfish_rtc.c
+++ b/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"
 
diff --git a/hw/rtc/m41t80.c b/hw/rtc/m41t80.c
index 396d110ba2d..a00971a67e1 100644
--- a/hw/rtc/m41t80.c
+++ b/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)
diff --git a/hw/rtc/m48t59.c b/hw/rtc/m48t59.c
index 690f4e071a1..74345d9d900 100644
--- a/hw/rtc/m48t59.c
+++ b/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"
diff --git a/hw/rtc/mc146818rtc.c b/hw/rtc/mc146818rtc.c
index 4fbafddb226..e61a0cced4c 100644
--- a/hw/rtc/mc146818rtc.c
+++ b/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"
diff --git a/hw/rtc/pl031.c b/hw/rtc/pl031.c
index e7ced90b025..38d9d3c2f38 100644
--- a/hw/rtc/pl031.c
+++ b/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"
diff --git a/hw/rtc/twl92230.c b/hw/rtc/twl92230.c
index 0922df5ad30..e8d5eda3fcf 100644
--- a/hw/rtc/twl92230.c
+++ b/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"
diff --git a/hw/rtc/xlnx-zynqmp-rtc.c b/hw/rtc/xlnx-zynqmp-rtc.c
index 2bcd14d7795..3e7d61a41c1 100644
--- a/hw/rtc/xlnx-zynqmp-rtc.c
+++ b/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"
diff --git a/hw/s390x/tod-tcg.c b/hw/s390x/tod-tcg.c
index 9bb94ff72bc..7646b4aa380 100644
--- a/hw/s390x/tod-tcg.c
+++ b/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)
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 4ff51221d4c..77a570233e5 100644
--- a/hw/scsi/megasas.c
+++ b/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"
diff --git a/net/dump.c b/net/dump.c
index a07ba624011..6a63b153595 100644
--- a/net/dump.c
+++ b/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;
diff --git a/softmmu/rtc.c b/softmmu/rtc.c
index 5632684fc9d..7e2956f81e9 100644
--- a/softmmu/rtc.c
+++ b/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,
-- 
2.25.1

Re: [PATCH for-7.0] rtc: Move RTC function prototypes to their own header

Posted by Peter Maydell 2 years, 2 months ago

On Mon, 29 Nov 2021 at 20:55, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> 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>
> ---
> I have added documentation comments for the two functions, but
> since my understanding of them and their purpose is little shaky
> review would be welcome.

I forgot about this patch from November; since Philippe has reviewed
it I'll take it via target-arm.next.

thanks
-- PMM

Re: [PATCH for-7.0] rtc: Move RTC function prototypes to their own header

Posted by Philippe Mathieu-Daudé 2 years, 4 months ago

On 11/29/21 21:55, Peter Maydell wrote:
> 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>
> ---
> I have added documentation comments for the two functions, but
> since my understanding of them and their purpose is little shaky
> review would be welcome.
> ---
>  include/qemu-common.h    |  3 ---
>  include/sysemu/rtc.h     | 58 ++++++++++++++++++++++++++++++++++++++++
>  hw/arm/omap1.c           |  2 +-
>  hw/arm/pxa2xx.c          |  2 +-
>  hw/arm/strongarm.c       |  2 +-
>  hw/misc/mac_via.c        |  2 +-
>  hw/misc/macio/cuda.c     |  2 +-
>  hw/misc/macio/pmu.c      |  2 +-
>  hw/ppc/spapr_rtc.c       |  2 +-
>  hw/rtc/allwinner-rtc.c   |  2 +-
>  hw/rtc/aspeed_rtc.c      |  2 +-
>  hw/rtc/ds1338.c          |  2 +-
>  hw/rtc/exynos4210_rtc.c  |  2 +-
>  hw/rtc/goldfish_rtc.c    |  2 +-
>  hw/rtc/m41t80.c          |  2 +-
>  hw/rtc/m48t59.c          |  2 +-
>  hw/rtc/mc146818rtc.c     |  2 +-
>  hw/rtc/pl031.c           |  2 +-
>  hw/rtc/twl92230.c        |  2 +-
>  hw/rtc/xlnx-zynqmp-rtc.c |  2 +-
>  hw/s390x/tod-tcg.c       |  2 +-
>  hw/scsi/megasas.c        |  2 +-
>  net/dump.c               |  2 +-
>  softmmu/rtc.c            |  2 +-
>  24 files changed, 80 insertions(+), 25 deletions(-)
>  create mode 100644 include/sysemu/rtc.h
> 
> diff --git a/include/qemu-common.h b/include/qemu-common.h
> index 73bcf763ed8..bed0b06a3d2 100644
> --- a/include/qemu-common.h
> +++ b/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)
> diff --git a/include/sysemu/rtc.h b/include/sysemu/rtc.h
> new file mode 100644
> index 00000000000..159702b45b5
> --- /dev/null
> +++ b/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);

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>