nvme: Nvme controller generated events

Interface for the nvme driver notifying its children of different
events: async notifications, namespace events and device failure. These
aren't yet connected.

Sponsored by:		Netflix
Reviewed by:	dab
Differential Revision:	https://reviews.freebsd.org/D51386

2 files changed, 56 insertions, 0 deletions

diff --git a/sys/conf/files b/sys/conf/files
index 3314274b47a8..9c5220c7befa 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -2571,6 +2571,7 @@ dev/nvme/nvme_sim.c		optional nvme scbus
 dev/nvme/nvme_sysctl.c		optional nvme
 dev/nvme/nvme_test.c		optional nvme
 dev/nvme/nvme_util.c		optional nvme | scbus
+dev/nvme/nvme_if.m		optional nvme
 dev/nvmem/nvmem.c		optional nvmem fdt
 dev/nvmem/nvmem_if.m		optional nvmem
 dev/nvmf/controller/ctl_frontend_nvmf.c		optional nvmft
diff --git a/sys/dev/nvme/nvme_if.m b/sys/dev/nvme/nvme_if.m
new file mode 100644
index 000000000000..a89381d165f7
--- /dev/null
+++ b/sys/dev/nvme/nvme_if.m
@@ -0,0 +1,55 @@
+# Copyright (c) 2025 Netlix, Inc
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+# Interface from the NVME controller to its children to notify it of certain
+# interesting events.
+
+INTERFACE nvme;
+
+HEADER {
+	#include "dev/nvme/nvme_private.h"
+};
+
+#
+# A new namespace is now available
+#
+METHOD int ns_added {
+	device_t	dev;		/* nvme device */
+	struct nvme_namespace *ns;	/* information about the namespace */
+};
+
+#
+# A namespace has been removed
+#
+METHOD int ns_removed {
+	device_t	dev;		/* nvme device */
+	struct nvme_namespace *ns;	/* information about the namespace */
+};
+
+#
+# A namespace has been changed somehow
+#
+METHOD int ns_changed {
+	device_t	dev;		/* nvme device */
+	struct nvme_namespace *ns;	/* information about the namespace */
+};
+
+#
+# The controller has failed
+#
+METHOD int controller_failed {
+	device_t	dev;		/* nvme device */
+};
+
+#
+# Async completion
+#
+METHOD int handle_aen {
+	device_t	dev;		/* nvme device */
+	const struct nvme_completion *cpl; /* Completion for this async event */
+	uint32_t	pg_nr;		/* Page number reported by async event */
+	void		*page;		/* Contents of the page */
+	uint32_t	page_len;	/* Length of the page */
+};