aboutsummaryrefslogtreecommitdiff
path: root/hw
diff options
context:
space:
mode:
authorDamien Hedde <damien.hedde@greensocs.com>2020-01-30 16:02:04 +0000
committerPeter Maydell <peter.maydell@linaro.org>2020-01-30 16:02:04 +0000
commit614f731adb9cc86bd45ce749f597e68dbde253b1 (patch)
tree4e0162e867fff4b649b6d9ae25eb1a691eb5e8dd /hw
parentc11256aa6fdd3971ef1dff23dfd8422049558d77 (diff)
hw/core/resettable: add support for changing parent
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>
Diffstat (limited to 'hw')
-rw-r--r--hw/core/resettable.c62
-rw-r--r--hw/core/trace-events1
2 files changed, 61 insertions, 2 deletions
diff --git a/hw/core/resettable.c b/hw/core/resettable.c
index 9133208487..6e0b0f492f 100644
--- a/hw/core/resettable.c
+++ b/hw/core/resettable.c
@@ -28,12 +28,16 @@ static void resettable_phase_exit(Object *obj, void *opaque, ResetType type);
* enter_phase_in_progress:
* True if we are currently in reset enter phase.
*
- * Note: This flag is only used to guarantee (using asserts) that the reset
- * API is used correctly. We can use a global variable because we rely on the
+ * exit_phase_in_progress:
+ * count the number of exit phase we are in.
+ *
+ * Note: These flags are only used to guarantee (using asserts) that the reset
+ * API is used correctly. We can use global variables because we rely on the
* iothread mutex to ensure only one reset operation is in a progress at a
* given time.
*/
static bool enter_phase_in_progress;
+static unsigned exit_phase_in_progress;
void resettable_reset(Object *obj, ResetType type)
{
@@ -65,7 +69,9 @@ void resettable_release_reset(Object *obj, ResetType type)
trace_resettable_reset_release_begin(obj, type);
assert(!enter_phase_in_progress);
+ exit_phase_in_progress += 1;
resettable_phase_exit(obj, NULL, type);
+ exit_phase_in_progress -= 1;
trace_resettable_reset_release_end(obj);
}
@@ -206,6 +212,58 @@ static void resettable_phase_exit(Object *obj, void *opaque, ResetType type)
trace_resettable_phase_exit_end(obj, obj_typename, s->count);
}
+/*
+ * resettable_get_count:
+ * Get the count of the Resettable object @obj. Return 0 if @obj is NULL.
+ */
+static unsigned resettable_get_count(Object *obj)
+{
+ if (obj) {
+ ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+ return rc->get_state(obj)->count;
+ }
+ return 0;
+}
+
+void resettable_change_parent(Object *obj, Object *newp, Object *oldp)
+{
+ ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+ ResettableState *s = rc->get_state(obj);
+ unsigned newp_count = resettable_get_count(newp);
+ unsigned oldp_count = resettable_get_count(oldp);
+
+ /*
+ * Ensure we do not change parent when in enter or exit phase.
+ * During these phases, the reset subtree being updated is partly in reset
+ * and partly not in reset (it depends on the actual position in
+ * resettable_child_foreach()s). We are not able to tell in which part is a
+ * leaving or arriving device. Thus we cannot set the reset count of the
+ * moving device to the proper value.
+ */
+ assert(!enter_phase_in_progress && !exit_phase_in_progress);
+ trace_resettable_change_parent(obj, oldp, oldp_count, newp, newp_count);
+
+ /*
+ * At most one of the two 'for' loops will be executed below
+ * in order to cope with the difference between the two counts.
+ */
+ /* if newp is more reset than oldp */
+ for (unsigned i = oldp_count; i < newp_count; i++) {
+ resettable_assert_reset(obj, RESET_TYPE_COLD);
+ }
+ /*
+ * if obj is leaving a bus under reset, we need to ensure
+ * hold phase is not pending.
+ */
+ if (oldp_count && s->hold_phase_pending) {
+ resettable_phase_hold(obj, NULL, RESET_TYPE_COLD);
+ }
+ /* if oldp is more reset than newp */
+ for (unsigned i = newp_count; i < oldp_count; i++) {
+ resettable_release_reset(obj, RESET_TYPE_COLD);
+ }
+}
+
void resettable_class_set_parent_phases(ResettableClass *rc,
ResettableEnterPhase enter,
ResettableHoldPhase hold,
diff --git a/hw/core/trace-events b/hw/core/trace-events
index 77d61cb66e..aecd8e160e 100644
--- a/hw/core/trace-events
+++ b/hw/core/trace-events
@@ -16,6 +16,7 @@ resettable_reset_assert_begin(void *obj, int cold) "obj=%p cold=%d"
resettable_reset_assert_end(void *obj) "obj=%p"
resettable_reset_release_begin(void *obj, int cold) "obj=%p cold=%d"
resettable_reset_release_end(void *obj) "obj=%p"
+resettable_change_parent(void *obj, void *o, unsigned oc, void *n, unsigned nc) "obj=%p from=%p(%d) to=%p(%d)"
resettable_phase_enter_begin(void *obj, const char *objtype, unsigned count, int type) "obj=%p(%s) count=%d type=%d"
resettable_phase_enter_exec(void *obj, const char *objtype, int type, int has_method) "obj=%p(%s) type=%d method=%d"
resettable_phase_enter_end(void *obj, const char *objtype, unsigned count) "obj=%p(%s) count=%d"