[PATCH] opal: Use empty structure when not defined

From: Keith Busch <keith.busch@intel.com>
To: linux-block@vger.kernel.org, Scott Bauer <scott.bauer@intel.com>,
	Jonathan Derrick <jonathan.derrick@intel.com>
Cc: Jens Axboe <axboe@fb.com>, Keith Busch <keith.busch@intel.com>
Subject: [PATCH] opal: Use empty structure when not defined
Date: Wed, 15 Feb 2017 19:16:27 -0500	[thread overview]
Message-ID: <1487204187-4004-1-git-send-email-keith.busch@intel.com> (raw)

No need to use space if it can't be used. This reduces the size of struct
nvme_ctrl by a little over 4k when CONFIG_BLK_SED_OPAL is not set.

Signed-off-by: Keith Busch <keith.busch@intel.com>
---
 include/linux/sed-opal.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/sed-opal.h b/include/linux/sed-opal.h
index 205d520..ed19902 100644
--- a/include/linux/sed-opal.h
+++ b/include/linux/sed-opal.h
@@ -91,6 +91,7 @@ struct parsed_resp {
 	struct opal_resp_tok toks[MAX_TOKS];
 };
 
+#ifdef CONFIG_BLK_SED_OPAL
 /**
  * struct opal_dev - The structure representing a OPAL enabled SED.
  * @supported: Whether or not OPAL is supported on this controller.
@@ -129,7 +130,6 @@ struct opal_dev {
 	struct list_head unlk_lst;
 };
 
-#ifdef CONFIG_BLK_SED_OPAL
 bool opal_unlock_from_suspend(struct opal_dev *dev);
 void init_opal_dev(struct opal_dev *opal_dev, sec_send_recv *send_recv);
 int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *ioctl_ptr);
@@ -154,6 +154,9 @@ static inline bool is_sed_ioctl(unsigned int cmd)
 	return false;
 }
 #else
+struct opal_dev {
+};
+
 static inline bool is_sed_ioctl(unsigned int cmd)
 {
 	return false;
@@ -171,8 +174,6 @@ static inline bool opal_unlock_from_suspend(struct opal_dev *dev)
 static inline void init_opal_dev(struct opal_dev *opal_dev,
 				 sec_send_recv *send_recv)
 {
-	opal_dev->supported = false;
-	opal_dev->initialized = true;
 }
 #endif /* CONFIG_BLK_SED_OPAL */
 #endif /* LINUX_OPAL_H */
-- 
2.5.5
