[PATCH 2/2] modules/firmware: add a new option to denote a firmware group to choose one.

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

This adds a tag that will go into the module info, only one firmware from
the group given needs to be available for this driver to work. This allows
dracut to avoid adding in firmware that aren't needed.

This just brackets a module list in the modinfo, the modules in the list
will get entries in reversed order so the last module in the list is the
preferred one.

The corresponding dracut code it at:
https://github.com/dracutdevs/dracut/pull/2309

Cc: Luis Chamberlain <mcgrof at kernel.org>
Cc: linux-modules at vger.kernel.org
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 include/linux/module.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/include/linux/module.h b/include/linux/module.h
index f9d072a7e198..d3e7085cedd0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -306,6 +306,28 @@ extern typeof(name) __mod_##type##__##name##_device_table		\
  */
 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 
+/**
+ * MODULE_FIRMWARE_GROUP_ONLY_ONE - Create a need only one firmware group
+ * @_grpname: group name
+ *
+ * This creates a group of which the driver only needs one firmware installed.
+ * This is to allow dracut to limit the number of firmwares in the initramfs.
+ * This just creates a new entry in the modinfo section, there should be one
+ * of these entries bracketing the group of MODULE_INFO lines.
+ * Due to how modinfo is constructed the ordering of the modinfo means the
+ * last module info in the group will end up being the first one dracut will
+ * search for, so place the newest firmware last.
+ *
+ * ``MODULE_FIRMWARE_GROUP_ONLY_ONE("mygroup")``
+ *
+ * ``MODULE_FIRMWARE("firmwarev1")``
+ *
+ * ``MODULE_FIRMWARE("firmwarev2")``
+ *
+ * ``MODULE_FIRMWARE_GROUP_ONLY_ONE("mygroup")``
+ */
+#define MODULE_FIRMWARE_GROUP_ONLY_ONE(_grpname) MODULE_INFO(firmware_group_only_one, _grpname)
+
 /**
  * MODULE_IMPORT_NS - Set the symbol namespace for the module.
  * @ns: symbol namespace to import the module into.
-- 
2.39.2