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* hw/core: deprecate old reset functions and introduce new onesDamien Hedde2020-01-301-0/+9
| | | | | | | | | | | | | | | | | | | | | Deprecate device_legacy_reset(), qdev_reset_all() and qbus_reset_all() to be replaced by new functions device_cold_reset() and bus_cold_reset() which uses resettable API. Also introduce resettable_cold_reset_fn() which may be used as a replacement for qdev_reset_all_fn and qbus_reset_all_fn(). Following patches will be needed to look at legacy reset call sites and switch to resettable api. The legacy functions will be removed when unused. Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200123132823.1117486-9-damien.hedde@greensocs.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
* hw/core/qdev: update hotplug reset regarding resettableDamien Hedde2020-01-301-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | This commit make use of the resettable API to reset the device being hotplugged when it is realized. Also it ensures it is put in a reset state coherent with the parent it is plugged into. Note that there is a difference in the reset. Instead of resetting only the hotplugged device, we reset also its subtree (switch to resettable API). This is not expected to be a problem because sub-buses are just realized too. If a hotplugged device has any sub-buses it is logical to reset them too at this point. The recently added should_be_hidden and PCI's partially_hotplugged mechanisms do not interfere with realize operation: + In the should_be_hidden use case, device creation is delayed. + The partially_hotplugged mechanism prevents a device to be unplugged and unrealized from qdev POV and unrealized. Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200123132823.1117486-8-damien.hedde@greensocs.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
* hw/core/resettable: add support for changing parentDamien Hedde2020-01-301-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | Add a function resettable_change_parent() to do the required plumbing when changing the parent a of Resettable object. We need to make sure that the reset state of the object remains coherent with the reset state of the new parent. We make the 2 following hypothesis: + when an object is put in a parent under reset, the object goes in reset. + when an object is removed from a parent under reset, the object leaves reset. The added function avoids any glitch if both old and new parent are already in reset. Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200123132823.1117486-6-damien.hedde@greensocs.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
* hw/core: create Resettable QOM interfaceDamien Hedde2020-01-301-0/+211
This commit defines an interface allowing multi-phase reset. This aims to solve a problem of the actual single-phase reset (built in DeviceClass and BusClass): reset behavior is dependent on the order in which reset handlers are called. In particular doing external side-effect (like setting an qemu_irq) is problematic because receiving object may not be reset yet. The Resettable interface divides the reset in 3 well defined phases. To reset an object tree, all 1st phases are executed then all 2nd then all 3rd. See the comments in include/hw/resettable.h for a more complete description. The interface defines 3 phases to let the future possibility of holding an object into reset for some time. The qdev/qbus reset in DeviceClass and BusClass will be modified in following commits to use this interface. A mechanism is provided to allow executing a transitional reset handler in place of the 2nd phase which is executed in children-then-parent order inside a tree. This will allow to transition devices and buses smoothly while keeping the exact current qdev/qbus reset behavior for now. Documentation will be added in a following commit. Signed-off-by: Damien Hedde <damien.hedde@greensocs.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200123132823.1117486-4-damien.hedde@greensocs.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>