From: Israel Rukshin <israelr@mellanox.com>
Date: Tue, 19 May 2020 17:05:54 +0300
Subject: [PATCH] nvme: introduce NVME_INLINE_METADATA_SG_CNT
Git-commit: ba7ca2ae029607c7eb2c18e37e8bc0d2252d3d12
Patch-mainline: v5.8-rc1
References: jsc#SLE-15608

SGL size of metadata is usually small. Thus, 1 inline sg should cover
most cases. The macro will be used for pre-allocate a single SGL entry
for metadata. The preallocation of small inline SGLs depends on SG_CHAIN
capability so if the ARCH doesn't support SG_CHAIN, use the runtime
allocation for the SGL. This patch is a preparation for adding metadata
(T10-PI) over fabric support.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/host/nvme.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 5b5ed128fd9e..fa5c75501049 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -31,8 +31,10 @@ extern unsigned int admin_timeout;
 
 #ifdef CONFIG_ARCH_NO_SG_CHAIN
 #define  NVME_INLINE_SG_CNT  0
+#define  NVME_INLINE_METADATA_SG_CNT  0
 #else
 #define  NVME_INLINE_SG_CNT  2
+#define  NVME_INLINE_METADATA_SG_CNT  1
 #endif
 
 extern struct workqueue_struct *nvme_wq;
-- 
2.16.4