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[PATCH] remove magic '31' for netdev priv. alignment

To: netdev <netdev@xxxxxxxxxxx>
Subject: [PATCH] remove magic '31' for netdev priv. alignment
From: "Randy.Dunlap" <rddunlap@xxxxxxxx>
Date: Mon, 5 Apr 2004 15:56:54 -0700
Cc: jgarzik <jgarzik@xxxxxxxxx>
Organization: OSDL
Sender: netdev-bounce@xxxxxxxxxxx
[resend/rediff]

// linux-2.6.5
// remove magic number of '31' from net_device and private alignment;

diffstat:=
 drivers/net/net_init.c    |    8 +++++---
 include/linux/netdevice.h |    7 ++++++-
 2 files changed, 11 insertions(+), 4 deletions(-)


diff -Naurp ./drivers/net/net_init.c.orig ./drivers/net/net_init.c
--- ./drivers/net/net_init.c.orig       2004-04-03 19:36:16.000000000 -0800
+++ ./drivers/net/net_init.c    2004-04-05 15:46:26.000000000 -0700
@@ -79,8 +79,9 @@ struct net_device *alloc_netdev(int size
 
        /* ensure 32-byte alignment of both the device and private area */
 
-       alloc_size = (sizeof(struct net_device) + 31) & ~31;
-       alloc_size += sizeof_priv + 31;
+       alloc_size = (sizeof(struct net_device) + NETDEV_ALIGN_CONST)
+                       & ~NETDEV_ALIGN_CONST;
+       alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;
 
        p = kmalloc (alloc_size, GFP_KERNEL);
        if (!p) {
@@ -90,7 +91,8 @@ struct net_device *alloc_netdev(int size
 
        memset(p, 0, alloc_size);
 
-       dev = (struct net_device *)(((long)p + 31) & ~31);
+       dev = (struct net_device *)(((long)p + NETDEV_ALIGN_CONST)
+                               & ~NETDEV_ALIGN_CONST);
        dev->padded = (char *)dev - (char *)p;
 
        if (sizeof_priv)
diff -Naurp ./include/linux/netdevice.h.orig ./include/linux/netdevice.h
--- ./include/linux/netdevice.h.orig    2004-04-03 19:38:18.000000000 -0800
+++ ./include/linux/netdevice.h 2004-04-05 15:46:26.000000000 -0700
@@ -484,9 +484,14 @@ struct net_device
        int padded;
 };
 
+#define        NETDEV_ALIGN            32
+#define        NETDEV_ALIGN_CONST      (NETDEV_ALIGN - 1)
+
 static inline void *netdev_priv(struct net_device *dev)
 {
-       return (char *)dev + ((sizeof(struct net_device) + 31) & ~31);
+       return (char *)dev + ((sizeof(struct net_device)
+                                       + NETDEV_ALIGN_CONST)
+                               & ~NETDEV_ALIGN_CONST);
 }
 
 #define SET_MODULE_OWNER(dev) do { } while (0)


--
~Randy
"We have met the enemy and he is us."  -- Pogo (by Walt Kelly)

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