From: Leon Romanovsky <leonro@mellanox.com>
Date: Wed, 21 Feb 2018 18:12:43 +0200
Subject: RDMA/uverbs: Reduce number of command header flags checks
Patch-mainline: v4.17-rc1
Git-commit: 372e15c5db5f3f15423a2e6e6a71b77b39026ecf
References: bsc#1103992 FATE#326009

Simplify the code by directly checking the availability of extended
command flog instead of doing multiple shift operations.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/uverbs_main.c |   11 ++---------
 include/uapi/rdma/ib_user_verbs.h     |    5 +----
 2 files changed, 3 insertions(+), 13 deletions(-)

--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -657,19 +657,12 @@ static bool verify_command_idx(u32 comma
 static ssize_t process_hdr(struct ib_uverbs_cmd_hdr *hdr,
 			   u32 *command, bool *extended)
 {
-	u32 flags;
-
-	if (hdr->command & ~(u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
+	if (hdr->command & ~(u32)(IB_USER_VERBS_CMD_FLAG_EXTENDED |
 				   IB_USER_VERBS_CMD_COMMAND_MASK))
 		return -EINVAL;
 
 	*command = hdr->command & IB_USER_VERBS_CMD_COMMAND_MASK;
-	flags = (hdr->command &
-		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
-
-	*extended = flags & IB_USER_VERBS_CMD_FLAG_EXTENDED;
-	if (flags & ~IB_USER_VERBS_CMD_FLAG_EXTENDED)
-		return -EINVAL;
+	*extended = hdr->command & IB_USER_VERBS_CMD_FLAG_EXTENDED;
 
 	if (!verify_command_idx(*command, *extended))
 		return -EOPNOTSUPP;
--- a/include/uapi/rdma/ib_user_verbs.h
+++ b/include/uapi/rdma/ib_user_verbs.h
@@ -140,10 +140,7 @@ struct ib_uverbs_cq_moderation_caps {
  */
 
 #define IB_USER_VERBS_CMD_COMMAND_MASK 0xff
-#define IB_USER_VERBS_CMD_FLAGS_MASK 0xff000000u
-#define IB_USER_VERBS_CMD_FLAGS_SHIFT 24
-
-#define IB_USER_VERBS_CMD_FLAG_EXTENDED 0x80
+#define IB_USER_VERBS_CMD_FLAG_EXTENDED 0x80000000u
 
 struct ib_uverbs_cmd_hdr {
 	__u32 command;