netdev - [PATCH v2 net 1/4] net/ncsi: Avoid if statements in ncsi_suspend

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 20 Oct 2016 11:45:49 +1100
From:   Gavin Shan <gwshan@...ux.vnet.ibm.com>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, joel@....id.au,
        Gavin Shan <gwshan@...ux.vnet.ibm.com>
Subject: [PATCH v2 net 1/4] net/ncsi: Avoid if statements in ncsi_suspend_channel()

There are several if/else statements in the state machine implemented
by switch/case in ncsi_suspend_channel() to avoid duplicated code. It
makes the code a bit hard to be understood.

This drops if/else statements in ncsi_suspend_channel() to improve the
code readability as Joel Stanley suggested. Also, it becomes easy to
add more states in the state machine without affecting current code.
No logical changes introduced by this.

Suggested-by: Joel Stanley <joel@....id.au>
Signed-off-by: Gavin Shan <gwshan@...ux.vnet.ibm.com>
---
 net/ncsi/ncsi-manage.c | 78 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 50 insertions(+), 28 deletions(-)

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 5e509e5..655d0d6 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -540,42 +540,60 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 		nd->state = ncsi_dev_state_suspend_select;
 		/* Fall through */
 	case ncsi_dev_state_suspend_select:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_SP;
+		nca.package = np->id;
+		nca.channel = NCSI_RESERVED_CHANNEL;
+		if (ndp->flags & NCSI_DEV_HWA)
+			nca.bytes[0] = 0;
+		else
+			nca.bytes[0] = 1;
+
+		nd->state = ncsi_dev_state_suspend_dcnt;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			goto error;
+
+		break;
 	case ncsi_dev_state_suspend_dcnt:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_DCNT;
+		nca.package = np->id;
+		nca.channel = nc->id;
+
+		nd->state = ncsi_dev_state_suspend_dc;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			goto error;
+
+		break;
 	case ncsi_dev_state_suspend_dc:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_DC;
+		nca.package = np->id;
+		nca.channel = nc->id;
+		nca.bytes[0] = 1;
+
+		nd->state = ncsi_dev_state_suspend_deselect;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			goto error;
+
+		break;
 	case ncsi_dev_state_suspend_deselect:
 		ndp->pending_req_num = 1;
 
-		np = ndp->active_package;
-		nc = ndp->active_channel;
+		nca.type = NCSI_PKT_CMD_DP;
 		nca.package = np->id;
-		if (nd->state == ncsi_dev_state_suspend_select) {
-			nca.type = NCSI_PKT_CMD_SP;
-			nca.channel = NCSI_RESERVED_CHANNEL;
-			if (ndp->flags & NCSI_DEV_HWA)
-				nca.bytes[0] = 0;
-			else
-				nca.bytes[0] = 1;
-			nd->state = ncsi_dev_state_suspend_dcnt;
-		} else if (nd->state == ncsi_dev_state_suspend_dcnt) {
-			nca.type = NCSI_PKT_CMD_DCNT;
-			nca.channel = nc->id;
-			nd->state = ncsi_dev_state_suspend_dc;
-		} else if (nd->state == ncsi_dev_state_suspend_dc) {
-			nca.type = NCSI_PKT_CMD_DC;
-			nca.channel = nc->id;
-			nca.bytes[0] = 1;
-			nd->state = ncsi_dev_state_suspend_deselect;
-		} else if (nd->state == ncsi_dev_state_suspend_deselect) {
-			nca.type = NCSI_PKT_CMD_DP;
-			nca.channel = NCSI_RESERVED_CHANNEL;
-			nd->state = ncsi_dev_state_suspend_done;
-		}
+		nca.channel = NCSI_RESERVED_CHANNEL;
 
+		nd->state = ncsi_dev_state_suspend_done;
 		ret = ncsi_xmit_cmd(&nca);
-		if (ret) {
-			nd->state = ncsi_dev_state_functional;
-			return;
-		}
+		if (ret)
+			goto error;
 
 		break;
 	case ncsi_dev_state_suspend_done:
@@ -589,6 +607,10 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 		netdev_warn(nd->dev, "Wrong NCSI state 0x%x in suspend\n",
 			    nd->state);
 	}
+
+	return;
+error:
+	nd->state = ncsi_dev_state_functional;
 }
 
 static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
-- 
2.1.0