cxgb4 : Update ipv6 address handling api

This patch improves on previously added support for ipv6 addresses. The code
is consolidated to a single file and adds an api for use by dependent upper
level drivers such as cxgb4i/iw_cxgb4 etc.

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Deepak Singh <deepak.s@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/Makefile

@@ -4,6 +4,6 @@
 
 obj-$(CONFIG_CHELSIO_T4) += cxgb4.o
 
-cxgb4-objs := cxgb4_main.o l2t.o t4_hw.o sge.o
+cxgb4-objs := cxgb4_main.o l2t.o t4_hw.o sge.o clip_tbl.o
 cxgb4-$(CONFIG_CHELSIO_T4_DCB) +=  cxgb4_dcb.o
 cxgb4-$(CONFIG_DEBUG_FS) += cxgb4_debugfs.o

drivers/net/ethernet/chelsio/cxgb4/clip_tbl.c

@@ -0,0 +1,314 @@
+/*
+ *  This file is part of the Chelsio T4 Ethernet driver for Linux.
+ *  Copyright (C) 2003-2014 Chelsio Communications.  All rights reserved.
+ *
+ *  Written by Deepak (deepak.s@chelsio.com)
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the LICENSE file included in this
+ *  release for licensing terms and conditions.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/jhash.h>
+#include <linux/if_vlan.h>
+#include <net/addrconf.h>
+#include "cxgb4.h"
+#include "clip_tbl.h"
+
+static inline unsigned int ipv4_clip_hash(struct clip_tbl *c, const u32 *key)
+{
+	unsigned int clipt_size_half = c->clipt_size / 2;
+
+	return jhash_1word(*key, 0) % clipt_size_half;
+}
+
+static inline unsigned int ipv6_clip_hash(struct clip_tbl *d, const u32 *key)
+{
+	unsigned int clipt_size_half = d->clipt_size / 2;
+	u32 xor = key[0] ^ key[1] ^ key[2] ^ key[3];
+
+	return clipt_size_half +
+		(jhash_1word(xor, 0) % clipt_size_half);
+}
+
+static unsigned int clip_addr_hash(struct clip_tbl *ctbl, const u32 *addr,
+				   int addr_len)
+{
+	return addr_len == 4 ? ipv4_clip_hash(ctbl, addr) :
+				ipv6_clip_hash(ctbl, addr);
+}
+
+static int clip6_get_mbox(const struct net_device *dev,
+			  const struct in6_addr *lip)
+{
+	struct adapter *adap = netdev2adap(dev);
+	struct fw_clip_cmd c;
+
+	memset(&c, 0, sizeof(c));
+	c.op_to_write = htonl(FW_CMD_OP_V(FW_CLIP_CMD) |
+			      FW_CMD_REQUEST_F | FW_CMD_WRITE_F);
+	c.alloc_to_len16 = htonl(FW_CLIP_CMD_ALLOC_F | FW_LEN16(c));
+	*(__be64 *)&c.ip_hi = *(__be64 *)(lip->s6_addr);
+	*(__be64 *)&c.ip_lo = *(__be64 *)(lip->s6_addr + 8);
+	return t4_wr_mbox_meat(adap, adap->mbox, &c, sizeof(c), &c, false);
+}
+
+static int clip6_release_mbox(const struct net_device *dev,
+			      const struct in6_addr *lip)
+{
+	struct adapter *adap = netdev2adap(dev);
+	struct fw_clip_cmd c;
+
+	memset(&c, 0, sizeof(c));
+	c.op_to_write = htonl(FW_CMD_OP_V(FW_CLIP_CMD) |
+			      FW_CMD_REQUEST_F | FW_CMD_READ_F);
+	c.alloc_to_len16 = htonl(FW_CLIP_CMD_FREE_F | FW_LEN16(c));
+	*(__be64 *)&c.ip_hi = *(__be64 *)(lip->s6_addr);
+	*(__be64 *)&c.ip_lo = *(__be64 *)(lip->s6_addr + 8);
+	return t4_wr_mbox_meat(adap, adap->mbox, &c, sizeof(c), &c, false);
+}
+
+int cxgb4_clip_get(const struct net_device *dev, const u32 *lip, u8 v6)
+{
+	struct adapter *adap = netdev2adap(dev);
+	struct clip_tbl *ctbl = adap->clipt;
+	struct clip_entry *ce, *cte;
+	u32 *addr = (u32 *)lip;
+	int hash;
+	int addr_len;
+	int ret = 0;
+
+	if (v6)
+		addr_len = 16;
+	else
+		addr_len = 4;
+
+	hash = clip_addr_hash(ctbl, addr, addr_len);
+
+	read_lock_bh(&ctbl->lock);
+	list_for_each_entry(cte, &ctbl->hash_list[hash], list) {
+		if (addr_len == cte->addr_len &&
+		    memcmp(lip, cte->addr, cte->addr_len) == 0) {
+			ce = cte;
+			read_unlock_bh(&ctbl->lock);
+			goto found;
+		}
+	}
+	read_unlock_bh(&ctbl->lock);
+
+	write_lock_bh(&ctbl->lock);
+	if (!list_empty(&ctbl->ce_free_head)) {
+		ce = list_first_entry(&ctbl->ce_free_head,
+				      struct clip_entry, list);
+		list_del(&ce->list);
+		INIT_LIST_HEAD(&ce->list);
+		spin_lock_init(&ce->lock);
+		atomic_set(&ce->refcnt, 0);
+		atomic_dec(&ctbl->nfree);
+		ce->addr_len = addr_len;
+		memcpy(ce->addr, lip, addr_len);
+		list_add_tail(&ce->list, &ctbl->hash_list[hash]);
+		if (v6) {
+			ret = clip6_get_mbox(dev, (const struct in6_addr *)lip);
+			if (ret) {
+				write_unlock_bh(&ctbl->lock);
+				return ret;
+			}
+		}
+	} else {
+		write_unlock_bh(&ctbl->lock);
+		return -ENOMEM;
+	}
+	write_unlock_bh(&ctbl->lock);
+found:
+	atomic_inc(&ce->refcnt);
+
+	return 0;
+}
+EXPORT_SYMBOL(cxgb4_clip_get);
+
+void cxgb4_clip_release(const struct net_device *dev, const u32 *lip, u8 v6)
+{
+	struct adapter *adap = netdev2adap(dev);
+	struct clip_tbl *ctbl = adap->clipt;
+	struct clip_entry *ce, *cte;
+	u32 *addr = (u32 *)lip;
+	int hash;
+	int addr_len;
+
+	if (v6)
+		addr_len = 16;
+	else
+		addr_len = 4;
+
+	hash = clip_addr_hash(ctbl, addr, addr_len);
+
+	read_lock_bh(&ctbl->lock);
+	list_for_each_entry(cte, &ctbl->hash_list[hash], list) {
+		if (addr_len == cte->addr_len &&
+		    memcmp(lip, cte->addr, cte->addr_len) == 0) {
+			ce = cte;
+			read_unlock_bh(&ctbl->lock);
+			goto found;
+		}
+	}
+	read_unlock_bh(&ctbl->lock);
+
+	return;
+found:
+	write_lock_bh(&ctbl->lock);
+	spin_lock_bh(&ce->lock);
+	if (atomic_dec_and_test(&ce->refcnt)) {
+		list_del(&ce->list);
+		INIT_LIST_HEAD(&ce->list);
+		list_add_tail(&ce->list, &ctbl->ce_free_head);
+		atomic_inc(&ctbl->nfree);
+		if (v6)
+			clip6_release_mbox(dev, (const struct in6_addr *)lip);
+	}
+	spin_unlock_bh(&ce->lock);
+	write_unlock_bh(&ctbl->lock);
+}
+EXPORT_SYMBOL(cxgb4_clip_release);
+
+/* Retrieves IPv6 addresses from a root device (bond, vlan) associated with
+ * a physical device.
+ * The physical device reference is needed to send the actul CLIP command.
+ */
+static int cxgb4_update_dev_clip(struct net_device *root_dev,
+				 struct net_device *dev)
+{
+	struct inet6_dev *idev = NULL;
+	struct inet6_ifaddr *ifa;
+	int ret = 0;
+
+	idev = __in6_dev_get(root_dev);
+	if (!idev)
+		return ret;
+
+	read_lock_bh(&idev->lock);
+	list_for_each_entry(ifa, &idev->addr_list, if_list) {
+		ret = cxgb4_clip_get(dev, (const u32 *)ifa->addr.s6_addr, 1);
+		if (ret < 0)
+			break;
+	}
+	read_unlock_bh(&idev->lock);
+
+	return ret;
+}
+
+int cxgb4_update_root_dev_clip(struct net_device *dev)
+{
+	struct net_device *root_dev = NULL;
+	int i, ret = 0;
+
+	/* First populate the real net device's IPv6 addresses */
+	ret = cxgb4_update_dev_clip(dev, dev);
+	if (ret)
+		return ret;
+
+	/* Parse all bond and vlan devices layered on top of the physical dev */
+	root_dev = netdev_master_upper_dev_get_rcu(dev);
+	if (root_dev) {
+		ret = cxgb4_update_dev_clip(root_dev, dev);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < VLAN_N_VID; i++) {
+		root_dev = __vlan_find_dev_deep_rcu(dev, htons(ETH_P_8021Q), i);
+		if (!root_dev)
+			continue;
+
+		ret = cxgb4_update_dev_clip(root_dev, dev);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(cxgb4_update_root_dev_clip);
+
+int clip_tbl_show(struct seq_file *seq, void *v)
+{
+	struct adapter *adapter = seq->private;
+	struct clip_tbl *ctbl = adapter->clipt;
+	struct clip_entry *ce;
+	char ip[60];
+	int i;
+
+	read_lock_bh(&ctbl->lock);
+
+	seq_puts(seq, "IP Address                  Users\n");
+	for (i = 0 ; i < ctbl->clipt_size;  ++i) {
+		list_for_each_entry(ce, &ctbl->hash_list[i], list) {
+			ip[0] = '\0';
+			if (ce->addr_len == 16)
+				sprintf(ip, "%pI6c", ce->addr);
+			else
+				sprintf(ip, "%pI4c", ce->addr);
+			seq_printf(seq, "%-25s   %u\n", ip,
+				   atomic_read(&ce->refcnt));
+		}
+	}
+	seq_printf(seq, "Free clip entries : %d\n", atomic_read(&ctbl->nfree));
+
+	read_unlock_bh(&ctbl->lock);
+
+	return 0;
+}
+
+struct clip_tbl *t4_init_clip_tbl(unsigned int clipt_start,
+				  unsigned int clipt_end)
+{
+	struct clip_entry *cl_list;
+	struct clip_tbl *ctbl;
+	unsigned int clipt_size;
+	int i;
+
+	if (clipt_start >= clipt_end)
+		return NULL;
+	clipt_size = clipt_end - clipt_start + 1;
+	if (clipt_size < CLIPT_MIN_HASH_BUCKETS)
+		return NULL;
+
+	ctbl = t4_alloc_mem(sizeof(*ctbl) +
+			    clipt_size*sizeof(struct list_head));
+	if (!ctbl)
+		return NULL;
+
+	ctbl->clipt_start = clipt_start;
+	ctbl->clipt_size = clipt_size;
+	INIT_LIST_HEAD(&ctbl->ce_free_head);
+
+	atomic_set(&ctbl->nfree, clipt_size);
+	rwlock_init(&ctbl->lock);
+
+	for (i = 0; i < ctbl->clipt_size; ++i)
+		INIT_LIST_HEAD(&ctbl->hash_list[i]);
+
+	cl_list = t4_alloc_mem(clipt_size*sizeof(struct clip_entry));
+	ctbl->cl_list = (void *)cl_list;
+
+	for (i = 0; i < clipt_size; i++) {
+		INIT_LIST_HEAD(&cl_list[i].list);
+		list_add_tail(&cl_list[i].list, &ctbl->ce_free_head);
+	}
+
+	return ctbl;
+}
+
+void t4_cleanup_clip_tbl(struct adapter *adap)
+{
+	struct clip_tbl *ctbl = adap->clipt;
+
+	if (ctbl) {
+		if (ctbl->cl_list)
+			t4_free_mem(ctbl->cl_list);
+		t4_free_mem(ctbl);
+	}
+}
+EXPORT_SYMBOL(t4_cleanup_clip_tbl);

drivers/net/ethernet/chelsio/cxgb4/clip_tbl.h

@@ -0,0 +1,41 @@
+/*
+ *  This file is part of the Chelsio T4 Ethernet driver for Linux.
+ *  Copyright (C) 2003-2014 Chelsio Communications.  All rights reserved.
+ *
+ *  Written by Deepak (deepak.s@chelsio.com)
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the LICENSE file included in this
+ *  release for licensing terms and conditions.
+ */
+
+struct clip_entry {
+	spinlock_t lock;	/* Hold while modifying clip reference */
+	atomic_t refcnt;
+	struct list_head list;
+	u32 addr[4];
+	int addr_len;
+};
+
+struct clip_tbl {
+	unsigned int clipt_start;
+	unsigned int clipt_size;
+	rwlock_t lock;
+	atomic_t nfree;
+	struct list_head ce_free_head;
+	void *cl_list;
+	struct list_head hash_list[0];
+};
+
+enum {
+	CLIPT_MIN_HASH_BUCKETS = 2,
+};
+
+struct clip_tbl *t4_init_clip_tbl(unsigned int clipt_start,
+				  unsigned int clipt_end);
+int cxgb4_clip_get(const struct net_device *dev, const u32 *lip, u8 v6);
+void cxgb4_clip_release(const struct net_device *dev, const u32 *lip, u8 v6);
+int clip_tbl_show(struct seq_file *seq, void *v);
+int cxgb4_update_root_dev_clip(struct net_device *dev);
+void t4_cleanup_clip_tbl(struct adapter *adap);

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -668,6 +668,9 @@ struct adapter {
 	unsigned int l2t_start;
 	unsigned int l2t_end;
 	struct l2t_data *l2t;
+	unsigned int clipt_start;
+	unsigned int clipt_end;
+	struct clip_tbl *clipt;
 	void *uld_handle[CXGB4_ULD_MAX];
 	struct list_head list_node;
 	struct list_head rcu_node;