The specification says:
0x00 TIME_LOW R: Get current time, then return low-order 32-bits.
0x04 TIME_HIGH R: Return high 32-bits from previous TIME_LOW read.
...
To read the value, the kernel must perform an IO_READ(TIME_LOW),
which returns an unsigned 32-bit value, before an IO_READ(TIME_HIGH),
which returns a signed 32-bit value, corresponding to the higher half
of the full value.
However, we were just returning the current time for both. If the guest
is unlucky enough to read TIME_LOW and TIME_HIGH either side of an
overflow of the lower half, it will see time be in the future, before
jumping backwards on the next read, and Linux currently relies on the
atomicity guaranteed by the spec so is affected by this. Fix this
violation of the spec by caching the correct value for TIME_HIGH
whenever TIME_LOW is read, and returning that value for any TIME_HIGH
read.
Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200718004934.83174-1-jrtc27@jrtc27.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Add and use RTC_ISA_BASE define instead of hardcoding 0x70.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20200429140003.7336-7-kraxel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Allwinner System-on-Chips usually contain a Real Time Clock (RTC)
for non-volatile system date and time keeping. This commit adds a generic
Allwinner RTC device that supports the RTC devices found in Allwinner SoC
family sun4i (A10), sun7i (A20) and sun6i and newer (A31, H2+, H3, etc).
The following RTC functionality and features are implemented:
* Year-Month-Day read/write
* Hour-Minute-Second read/write
* General Purpose storage
The following boards are extended with the RTC device:
* Cubieboard (hw/arm/cubieboard.c)
* Orange Pi PC (hw/arm/orangepi.c)
Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200311221854.30370-13-nieklinnenbank@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch adds model for Google Goldfish virtual platform RTC device.
We will be adding Goldfish RTC device to the QEMU RISC-V virt machine
for providing real date-time to Guest Linux. The corresponding Linux
driver for Goldfish RTC device is already available in upstream Linux.
For now, VM migration support is available but untested for Goldfish RTC
device. It will be hardened in-future when we implement VM migration for
KVM RISC-V.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
The system <stdint.h> include is already provided by "osdep.h"
(the scripts/clean-includes file clean such headers).
Commit 64552b6be4 suggests we don't need to include "hw/irq.h":
Move the qemu_irq and qemu_irq_handler typedefs from hw/irq.h to
qemu/typedefs.h, and then include hw/irq.h only where it's still
needed.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20191003230404.19384-15-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Only 2 source files require the "mc146818rtc_regs.h" header.
Instead of having it processed 12 times, by all objects
using "mc146818rtc.h", include it directly where used.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191003230404.19384-13-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Move RTC devices under the hw/rtc/ subdirectory.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20191003230404.19384-12-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The M48T59 is a Real Time Clock, not a timer.
Move it under the hw/rtc/ subdirectory.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191003230404.19384-5-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The MC146818 is a Real Time Clock, not a timer.
Move it under the hw/rtc/ subdirectory.
Use copyright statement from 80cabfad16 for "hw/rtc/mc146818rtc.h".
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191003230404.19384-4-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The PL031 is a Real Time Clock, not a timer.
Move it under the hw/rtc/ subdirectory.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20191003230404.19384-3-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
