net: Define enum for net device features.

Define feature values by bit position instead of direct 2**i values
and force the values to be of type netdev_features_t.

Cleaned and extended from patch by Mahesh Bandewar <maheshb@google.com>:
+ added netdev_features_t casts
+ included bits under NETIF_F_GSO_MASK
+ moved feature #defines out of struct net_device definition

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 93 insertions, 40 deletions

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index af5238121826..04ac8f8433e9 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -14,52 +14,105 @@
 
 typedef u32 netdev_features_t;
 
-/* Net device feature bits; if you change something,
- * also update netdev_features_strings[] in ethtool.c */
-
-#define NETIF_F_SG              1       /* Scatter/gather IO. */
-#define NETIF_F_IP_CSUM         2       /* Can checksum TCP/UDP over IPv4. */
-#define NETIF_F_NO_CSUM         4       /* Does not require checksum. F.e. loopack. */
-#define NETIF_F_HW_CSUM         8       /* Can checksum all the packets. */
-#define NETIF_F_IPV6_CSUM       16      /* Can checksum TCP/UDP over IPV6 */
-#define NETIF_F_HIGHDMA         32      /* Can DMA to high memory. */
-#define NETIF_F_FRAGLIST        64      /* Scatter/gather IO. */
-#define NETIF_F_HW_VLAN_TX      128     /* Transmit VLAN hw acceleration */
-#define NETIF_F_HW_VLAN_RX      256     /* Receive VLAN hw acceleration */
-#define NETIF_F_HW_VLAN_FILTER  512     /* Receive filtering on VLAN */
-#define NETIF_F_VLAN_CHALLENGED 1024    /* Device cannot handle VLAN packets */
-#define NETIF_F_GSO             2048    /* Enable software GSO. */
-#define NETIF_F_LLTX            4096    /* LockLess TX - deprecated. Please */
+enum {
+        NETIF_F_SG_BIT,                 /* Scatter/gather IO. */
+        NETIF_F_IP_CSUM_BIT,            /* Can checksum TCP/UDP over IPv4. */
+        NETIF_F_NO_CSUM_BIT,            /* Does not require checksum. F.e. loopack. */
+        NETIF_F_HW_CSUM_BIT,            /* Can checksum all the packets. */
+        NETIF_F_IPV6_CSUM_BIT,          /* Can checksum TCP/UDP over IPV6 */
+        NETIF_F_HIGHDMA_BIT,            /* Can DMA to high memory. */
+        NETIF_F_FRAGLIST_BIT,           /* Scatter/gather IO. */
+        NETIF_F_HW_VLAN_TX_BIT,         /* Transmit VLAN hw acceleration */
+        NETIF_F_HW_VLAN_RX_BIT,         /* Receive VLAN hw acceleration */
+        NETIF_F_HW_VLAN_FILTER_BIT,     /* Receive filtering on VLAN */
+        NETIF_F_VLAN_CHALLENGED_BIT,    /* Device cannot handle VLAN packets */
+        NETIF_F_GSO_BIT,                /* Enable software GSO. */
+        NETIF_F_LLTX_BIT,               /* LockLess TX - deprecated. Please */
                                         /* do not use LLTX in new drivers */
-#define NETIF_F_NETNS_LOCAL     8192    /* Does not change network namespaces */
-#define NETIF_F_GRO             16384   /* Generic receive offload */
-#define NETIF_F_LRO             32768   /* large receive offload */
-
-/* the GSO_MASK reserves bits 16 through 23 */
-#define NETIF_F_FCOE_CRC        (1 << 24) /* FCoE CRC32 */
-#define NETIF_F_SCTP_CSUM       (1 << 25) /* SCTP checksum offload */
-#define NETIF_F_FCOE_MTU        (1 << 26) /* Supports max FCoE MTU, 2158 bytes*/
-#define NETIF_F_NTUPLE          (1 << 27) /* N-tuple filters supported */
-#define NETIF_F_RXHASH          (1 << 28) /* Receive hashing offload */
-#define NETIF_F_RXCSUM          (1 << 29) /* Receive checksumming offload */
-#define NETIF_F_NOCACHE_COPY    (1 << 30) /* Use no-cache copyfromuser */
-#define NETIF_F_LOOPBACK        (1 << 31) /* Enable loopback */
-
-/* Segmentation offload features */
-#define NETIF_F_GSO_SHIFT       16
-#define NETIF_F_GSO_MASK        0x00ff0000
-#define NETIF_F_TSO             (SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT)
-#define NETIF_F_UFO             (SKB_GSO_UDP << NETIF_F_GSO_SHIFT)
-#define NETIF_F_GSO_ROBUST      (SKB_GSO_DODGY << NETIF_F_GSO_SHIFT)
-#define NETIF_F_TSO_ECN         (SKB_GSO_TCP_ECN << NETIF_F_GSO_SHIFT)
-#define NETIF_F_TSO6            (SKB_GSO_TCPV6 << NETIF_F_GSO_SHIFT)
-#define NETIF_F_FSO             (SKB_GSO_FCOE << NETIF_F_GSO_SHIFT)
+        NETIF_F_NETNS_LOCAL_BIT,        /* Does not change network namespaces */
+        NETIF_F_GRO_BIT,                /* Generic receive offload */
+        NETIF_F_LRO_BIT,                /* large receive offload */
+
+        /**/NETIF_F_GSO_SHIFT,          /* keep the order of SKB_GSO_* bits */
+        NETIF_F_TSO_BIT                 /* ... TCPv4 segmentation */
+                = NETIF_F_GSO_SHIFT,
+        NETIF_F_UFO_BIT,                /* ... UDPv4 fragmentation */
+        NETIF_F_GSO_ROBUST_BIT,         /* ... ->SKB_GSO_DODGY */
+        NETIF_F_TSO_ECN_BIT,            /* ... TCP ECN support */
+        NETIF_F_TSO6_BIT,               /* ... TCPv6 segmentation */
+        NETIF_F_FSO_BIT,                /* ... FCoE segmentation */
+        NETIF_F_GSO_RESERVED1,          /* ... free (fill GSO_MASK to 8 bits) */
+        /**/NETIF_F_GSO_LAST,           /* [can't be last bit, see GSO_MASK] */
+        NETIF_F_GSO_RESERVED2           /* ... free (fill GSO_MASK to 8 bits) */
+                = NETIF_F_GSO_LAST,
+
+        NETIF_F_FCOE_CRC_BIT,           /* FCoE CRC32 */
+        NETIF_F_SCTP_CSUM_BIT,          /* SCTP checksum offload */
+        NETIF_F_FCOE_MTU_BIT,           /* Supports max FCoE MTU, 2158 bytes*/
+        NETIF_F_NTUPLE_BIT,             /* N-tuple filters supported */
+        NETIF_F_RXHASH_BIT,             /* Receive hashing offload */
+        NETIF_F_RXCSUM_BIT,             /* Receive checksumming offload */
+        NETIF_F_NOCACHE_COPY_BIT,       /* Use no-cache copyfromuser */
+        NETIF_F_LOOPBACK_BIT,           /* Enable loopback */
+
+        /*
+         * Add your fresh new feature above and remember to update
+         * netdev_features_strings[] in net/core/ethtool.c and maybe
+         * some feature mask #defines below. Please also describe it
+         * in Documentation/networking/netdev-features.txt.
+         */
+
+        /**/NETDEV_FEATURE_COUNT
+};
+
+/* copy'n'paste compression ;) */
+#define __NETIF_F_BIT(bit)      ((netdev_features_t)1 << (bit))
+#define __NETIF_F(name)         __NETIF_F_BIT(NETIF_F_##name##_BIT)
+
+#define NETIF_F_FCOE_CRC        __NETIF_F(FCOE_CRC)
+#define NETIF_F_FCOE_MTU        __NETIF_F(FCOE_MTU)
+#define NETIF_F_FRAGLIST        __NETIF_F(FRAGLIST)
+#define NETIF_F_FSO             __NETIF_F(FSO)
+#define NETIF_F_GRO             __NETIF_F(GRO)
+#define NETIF_F_GSO             __NETIF_F(GSO)
+#define NETIF_F_GSO_ROBUST      __NETIF_F(GSO_ROBUST)
+#define NETIF_F_HIGHDMA         __NETIF_F(HIGHDMA)
+#define NETIF_F_HW_CSUM         __NETIF_F(HW_CSUM)
+#define NETIF_F_HW_VLAN_FILTER  __NETIF_F(HW_VLAN_FILTER)
+#define NETIF_F_HW_VLAN_RX      __NETIF_F(HW_VLAN_RX)
+#define NETIF_F_HW_VLAN_TX      __NETIF_F(HW_VLAN_TX)
+#define NETIF_F_IP_CSUM         __NETIF_F(IP_CSUM)
+#define NETIF_F_IPV6_CSUM       __NETIF_F(IPV6_CSUM)
+#define NETIF_F_LLTX            __NETIF_F(LLTX)
+#define NETIF_F_LOOPBACK        __NETIF_F(LOOPBACK)
+#define NETIF_F_LRO             __NETIF_F(LRO)
+#define NETIF_F_NETNS_LOCAL     __NETIF_F(NETNS_LOCAL)
+#define NETIF_F_NOCACHE_COPY    __NETIF_F(NOCACHE_COPY)
+#define NETIF_F_NO_CSUM         __NETIF_F(NO_CSUM)
+#define NETIF_F_NTUPLE          __NETIF_F(NTUPLE)
+#define NETIF_F_RXCSUM          __NETIF_F(RXCSUM)
+#define NETIF_F_RXHASH          __NETIF_F(RXHASH)
+#define NETIF_F_SCTP_CSUM       __NETIF_F(SCTP_CSUM)
+#define NETIF_F_SG              __NETIF_F(SG)
+#define NETIF_F_TSO6            __NETIF_F(TSO6)
+#define NETIF_F_TSO_ECN         __NETIF_F(TSO_ECN)
+#define NETIF_F_TSO             __NETIF_F(TSO)
+#define NETIF_F_UFO             __NETIF_F(UFO)
+#define NETIF_F_VLAN_CHALLENGED __NETIF_F(VLAN_CHALLENGED)
 
 /* Features valid for ethtool to change */
 /* = all defined minus driver/device-class-related */
 #define NETIF_F_NEVER_CHANGE    (NETIF_F_VLAN_CHALLENGED | \
                                  NETIF_F_LLTX | NETIF_F_NETNS_LOCAL)
-#define NETIF_F_ETHTOOL_BITS    (0xff3fffff & ~NETIF_F_NEVER_CHANGE)
+
+/* remember that ((t)1 << t_BITS) is undefined in C99 */
+#define NETIF_F_ETHTOOL_BITS    ((__NETIF_F_BIT(NETDEV_FEATURE_COUNT - 1) | \
+                (__NETIF_F_BIT(NETDEV_FEATURE_COUNT - 1) - 1)) & \
+                ~NETIF_F_NEVER_CHANGE)
+
+/* Segmentation offload feature mask */
+#define NETIF_F_GSO_MASK        (__NETIF_F_BIT(NETIF_F_GSO_LAST + 1) - \
+                __NETIF_F_BIT(NETIF_F_GSO_SHIFT))
 
 /* List of features with software fallbacks. */
 #define NETIF_F_GSO_SOFTWARE    (NETIF_F_TSO | NETIF_F_TSO_ECN | \