[RFC PATCH v5 1/4] lib: sbi_domain: Add domain register finalize notifier

[Rahul Pathak]

sbi domain registeration notifier is invoked when
memory regions of the domains are not finalized. The root
domain is registered early and the drivers keep adding
the regions until sbi_domain_finalize() is called. Such regions
are added to the root after root domain is already registered
and notification for that has already been sent.

Per-domain configuration which is based on the final memory
regions of the domains especially the root domain is not
possible only with a domain register notifier.

Add a domain finalize notifier for such case which is called
for every domain once all the domains are already registered and
their memory regions are finalized.

Signed-off-by: Rahul Pathak <rahul.pathak at oss.qualcomm.com>
---
 include/sbi/sbi_domain.h | 16 ++++++++
 lib/sbi/sbi_domain.c     | 80 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/include/sbi/sbi_domain.h b/include/sbi/sbi_domain.h
index 39e6fc81..a96d709d 100644
--- a/include/sbi/sbi_domain.h
+++ b/include/sbi/sbi_domain.h
@@ -362,10 +362,26 @@ int sbi_domain_init(struct sbi_scratch *scratch, u32 cold_hartid);
 typedef void (*sbi_domain_notifier_fn)(const struct sbi_domain *dom,
                                       void *priv);
 
+/**
+ * Domain finalize notifier callback
+ *
+ * Invoked from sbi_domain_finalize  function after every domain gets
+ * registered and memory regions of all domains are finalized.
+ */
+typedef int (*sbi_domain_finalize_notifier_fn)(struct sbi_domain *dom, void *priv);
+
 /** Regitser domain notifier */
 int sbi_domain_register_notifier(sbi_domain_notifier_fn notifier, void *priv);
 
 /** Unregitser domain notifier */
 int sbi_domain_unregister_notifier(sbi_domain_notifier_fn notifier, void *priv);
 
+/** Register domain finalize notifier */
+int sbi_domain_register_finalize_notifier(sbi_domain_finalize_notifier_fn notifier,
+					  void *priv);
+
+/** Unregister domain finalize notifier */
+int sbi_domain_unregister_finalize_notifier(sbi_domain_finalize_notifier_fn notifier,
+					    void *priv);
+
 #endif
diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
index c0583efc..913f8142 100644
--- a/lib/sbi/sbi_domain.c
+++ b/lib/sbi/sbi_domain.c
@@ -42,8 +42,15 @@ struct sbi_domain_notifier_entry {
 };
 
 
+struct sbi_domain_finalize_notifier_entry {
+	struct sbi_dlist			node;
+	sbi_domain_finalize_notifier_fn		fn;
+	void					*priv;
+};
+
 static unsigned long domain_hart_ptr_offset;
 static SBI_LIST_HEAD(domain_notifier_list);
+static SBI_LIST_HEAD(domain_finalize_notifier_list);
 
 int sbi_domain_register_notifier(sbi_domain_notifier_fn notifier, void *priv)
 {
@@ -95,6 +102,67 @@ void sbi_domain_notify_all(const struct sbi_domain *dom)
 	}
 }
 
+int sbi_domain_register_finalize_notifier(sbi_domain_finalize_notifier_fn notifier, void *priv)
+{
+	struct sbi_domain_finalize_notifier_entry *entry;
+
+	if (!notifier)
+		return SBI_EINVAL;
+
+	sbi_list_for_each_entry(entry, &domain_finalize_notifier_list, node) {
+		if (entry->fn == notifier && entry->priv == priv)
+			return SBI_OK;
+	}
+
+	entry = sbi_zalloc(sizeof(*entry));
+	if (!entry)
+		return SBI_ENOMEM;
+
+	entry->fn = notifier;
+	entry->priv = priv;
+	sbi_list_add_tail(&entry->node, &domain_finalize_notifier_list);
+
+	return SBI_OK;
+}
+
+int sbi_domain_unregister_finalize_notifier(sbi_domain_finalize_notifier_fn notifier, void *priv)
+{
+	struct sbi_domain_finalize_notifier_entry *entry, *tmp;
+
+	if (!notifier)
+		return SBI_EINVAL;
+
+	sbi_list_for_each_entry_safe(entry, tmp, &domain_finalize_notifier_list, node) {
+		if (entry->fn == notifier && entry->priv == priv) {
+			sbi_list_del(&entry->node);
+			sbi_free(entry);
+			return SBI_OK;
+		}
+	}
+
+	return SBI_ENODEV;
+}
+
+static int sbi_domain_notify_finalize_all(void)
+{
+	struct sbi_domain_finalize_notifier_entry *entry;
+	struct sbi_domain *dom;
+	int rc;
+
+	sbi_list_for_each_entry(entry, &domain_finalize_notifier_list, node) {
+		if (!entry->fn)
+			continue;
+
+		sbi_domain_for_each(dom) {
+			rc = entry->fn(dom, entry->priv);
+			if (rc)
+				return rc;
+		}
+	}
+
+	return 0;
+}
+
 struct sbi_domain *sbi_hartindex_to_domain(u32 hartindex)
 {
 	struct sbi_scratch *scratch;
@@ -924,6 +992,18 @@ int sbi_domain_finalize(struct sbi_scratch *scratch)
 	 */
 	domain_finalized = true;
 
+	/*
+	 * All domains are registered and their memory regions are final
+	 * so notify the subsystems which derive per-domain configuration
+	 * from the domain memory regions.
+	 */
+	rc = sbi_domain_notify_finalize_all();
+	if (rc) {
+		sbi_printf("%s: domain finalize notifier failed (error %d)\n",
+			   __func__, rc);
+		return rc;
+	}
+
 	return 0;
 }
 
-- 
2.53.0