From 86fae16ed298518ea851d6accc48643e6bdf8ed1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 20 Feb 2024 16:06:19 +0000 Subject: [PATCH] hw/core/reset: Add qemu_{register, unregister}_resettable() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Implement new functions qemu_register_resettable() and qemu_unregister_resettable(). These are intended to be three-phase-reset aware equivalents of the old qemu_register_reset() and qemu_unregister_reset(). Instead of passing in a function pointer and opaque, you register any QOM object that implements the Resettable interface. The implementation is simple: we have a single global instance of a ResettableContainer, which we reset in qemu_devices_reset(), and the Resettable objects passed to qemu_register_resettable() are added to it. Signed-off-by: Peter Maydell Reviewed-by: Michael S. Tsirkin Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Daniel P. Berrangé Message-id: 20240220160622.114437-8-peter.maydell@linaro.org Reviewed-by: Zhao Liu --- hw/core/reset.c | 31 +++++++++++++++++++++++++++++-- include/sysemu/reset.h | 37 ++++++++++++++++++++++++++++++++++--- 2 files changed, 63 insertions(+), 5 deletions(-) diff --git a/hw/core/reset.c b/hw/core/reset.c index d3263b613e..a9b30e705f 100644 --- a/hw/core/reset.c +++ b/hw/core/reset.c @@ -26,8 +26,23 @@ #include "qemu/osdep.h" #include "qemu/queue.h" #include "sysemu/reset.h" +#include "hw/resettable.h" +#include "hw/core/resetcontainer.h" -/* reset/shutdown handler */ +/* + * Return a pointer to the singleton container that holds all the Resettable + * items that will be reset when qemu_devices_reset() is called. + */ +static ResettableContainer *get_root_reset_container(void) +{ + static ResettableContainer *root_reset_container; + + if (!root_reset_container) { + root_reset_container = + RESETTABLE_CONTAINER(object_new(TYPE_RESETTABLE_CONTAINER)); + } + return root_reset_container; +} typedef struct QEMUResetEntry { QTAILQ_ENTRY(QEMUResetEntry) entry; @@ -71,6 +86,16 @@ void qemu_unregister_reset(QEMUResetHandler *func, void *opaque) } } +void qemu_register_resettable(Object *obj) +{ + resettable_container_add(get_root_reset_container(), obj); +} + +void qemu_unregister_resettable(Object *obj) +{ + resettable_container_remove(get_root_reset_container(), obj); +} + void qemu_devices_reset(ShutdownCause reason) { QEMUResetEntry *re, *nre; @@ -83,5 +108,7 @@ void qemu_devices_reset(ShutdownCause reason) } re->func(re->opaque); } -} + /* Reset the simulation */ + resettable_reset(OBJECT(get_root_reset_container()), RESET_TYPE_COLD); +} diff --git a/include/sysemu/reset.h b/include/sysemu/reset.h index 658a7e091e..ef2c595e29 100644 --- a/include/sysemu/reset.h +++ b/include/sysemu/reset.h @@ -31,6 +31,36 @@ typedef void QEMUResetHandler(void *opaque); +/** + * qemu_register_resettable: Register an object to be reset + * @obj: object to be reset: it must implement the Resettable interface + * + * Register @obj on the list of objects which will be reset when the + * simulation is reset. These objects will be reset in the order + * they were added, using the three-phase Resettable protocol, + * so first all objects go through the enter phase, then all objects + * go through the hold phase, and then finally all go through the + * exit phase. + * + * It is not permitted to register or unregister reset functions or + * resettable objects from within any of the reset phase methods of @obj. + * + * We assume that the caller holds the BQL. + */ +void qemu_register_resettable(Object *obj); + +/** + * qemu_unregister_resettable: Unregister an object to be reset + * @obj: object to unregister + * + * Remove @obj from the list of objects which are reset when the + * simulation is reset. It must have been previously added to + * the list via qemu_register_resettable(). + * + * We assume that the caller holds the BQL. + */ +void qemu_unregister_resettable(Object *obj); + /** * qemu_register_reset: Register a callback for system reset * @func: function to call @@ -44,8 +74,8 @@ typedef void QEMUResetHandler(void *opaque); * for instance, device model reset is better accomplished using the * methods on DeviceState. * - * It is not permitted to register or unregister reset functions from - * within the @func callback. + * It is not permitted to register or unregister reset functions or + * resettable objects from within the @func callback. * * We assume that the caller holds the BQL. */ @@ -81,7 +111,8 @@ void qemu_unregister_reset(QEMUResetHandler *func, void *opaque); * * This function performs the low-level work needed to do a complete reset * of the system (calling all the callbacks registered with - * qemu_register_reset()). It should only be called by the code in a + * qemu_register_reset() and resetting all the Resettable objects registered + * with qemu_register_resettable()). It should only be called by the code in a * MachineClass reset method. * * If you want to trigger a system reset from, for instance, a device