[PATCH] zd1211rw: Support for multicast addresses

[PATCH] zd1211rw: Support for multicast addresses

[Daniel Drake]

From: Ulrich Kunitz <kune@deine-taler.de>

Support for multicast adresses is implemented by supporting the
set_multicast_list() function of the network device. Address
filtering is supported by a group hash table in the device.

This is based on earlier work by Benoit Papillaut. Fixes multicast packet
reception and ipv6 connectivity:
http://bugzilla.kernel.org/show_bug.cgi?id=7424
http://bugzilla.kernel.org/show_bug.cgi?id=7425

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Daniel Drake <dsd@gentoo.org>
---
 zd_chip.c   |   13 +++++++++++++
 zd_chip.h   |   43 ++++++++++++++++++++++++++++++++++++++++++-
 zd_mac.c    |   44 +++++++++++++++++++++++++++++++++++++++++++-
 zd_mac.h    |    3 +++
 zd_netdev.c |    2 +-
 5 files changed, 102 insertions(+), 3 deletions(-)

Index: linux-2.6/drivers/net/wireless/zd1211rw/zd_chip.c
===================================================================
--- linux-2.6.orig/drivers/net/wireless/zd1211rw/zd_chip.c
+++ linux-2.6/drivers/net/wireless/zd1211rw/zd_chip.c
@@ -1673,3 +1673,16 @@ int zd_rfwritev_cr_locked(struct zd_chip
 
 	return 0;
 }
+
+int zd_chip_set_multicast_hash(struct zd_chip *chip,
+	                       struct zd_mc_hash *hash)
+{
+	struct zd_ioreq32 ioreqs[] = {
+		{ CR_GROUP_HASH_P1, hash->low },
+		{ CR_GROUP_HASH_P2, hash->high },
+	};
+
+	dev_dbg_f(zd_chip_dev(chip), "hash l 0x%08x h 0x%08x\n",
+		ioreqs[0].value, ioreqs[1].value);
+	return zd_iowrite32a(chip, ioreqs, ARRAY_SIZE(ioreqs));
+}
Index: linux-2.6/drivers/net/wireless/zd1211rw/zd_chip.h
===================================================================
--- linux-2.6.orig/drivers/net/wireless/zd1211rw/zd_chip.h
+++ linux-2.6/drivers/net/wireless/zd1211rw/zd_chip.h
@@ -390,10 +390,19 @@
 #define CR_BSSID_P1			CTL_REG(0x0618)
 #define CR_BSSID_P2			CTL_REG(0x061C)
 #define CR_BCN_PLCP_CFG			CTL_REG(0x0620)
+
+/* Group hash table for filtering incoming packets.
+ *
+ * The group hash table is 64 bit large and split over two parts. The first
+ * part is the lower part. The upper 6 bits of the last byte of the target
+ * address are used as index. Packets are received if the hash table bit is
+ * set. This is used for multicast handling, but for broadcasts (address
+ * ff:ff:ff:ff:ff:ff) the highest bit in the second table must also be set.
+ */
 #define CR_GROUP_HASH_P1		CTL_REG(0x0624)
 #define CR_GROUP_HASH_P2		CTL_REG(0x0628)
-#define CR_RX_TIMEOUT			CTL_REG(0x062C)
 
+#define CR_RX_TIMEOUT			CTL_REG(0x062C)
 /* Basic rates supported by the BSS. When producing ACK or CTS messages, the
  * device will use a rate in this table that is less than or equal to the rate
  * of the incoming frame which prompted the response */
@@ -864,4 +873,36 @@ u8 zd_rx_strength_percent(u8 rssi);
 
 u16 zd_rx_rate(const void *rx_frame, const struct rx_status *status);
 
+struct zd_mc_hash {
+	u32 low;
+	u32 high;
+};
+
+static inline void zd_mc_clear(struct zd_mc_hash *hash)
+{
+	hash->low = 0;
+	/* The interfaces must always received broadcasts.
+	 * The hash of the broadcast address ff:ff:ff:ff:ff:ff is 63.
+	 */
+	hash->high = 0x80000000;
+}
+
+static inline void zd_mc_add_all(struct zd_mc_hash *hash)
+{
+	hash->low = hash->high = 0xffffffff;
+}
+
+static inline void zd_mc_add_addr(struct zd_mc_hash *hash, u8 *addr)
+{
+	unsigned int i = addr[5] >> 2;
+	if (i < 32) {
+		hash->low |= 1 << i;
+	} else {
+		hash->high |= 1 << (i-32);
+	}
+}
+
+int zd_chip_set_multicast_hash(struct zd_chip *chip,
+	                       struct zd_mc_hash *hash);
+
 #endif /* _ZD_CHIP_H */
Index: linux-2.6/drivers/net/wireless/zd1211rw/zd_mac.c
===================================================================
--- linux-2.6.orig/drivers/net/wireless/zd1211rw/zd_mac.c
+++ linux-2.6/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -39,6 +39,8 @@ static void housekeeping_init(struct zd_
 static void housekeeping_enable(struct zd_mac *mac);
 static void housekeeping_disable(struct zd_mac *mac);
 
+static void set_multicast_hash_handler(void *mac_ptr);
+
 int zd_mac_init(struct zd_mac *mac,
 	        struct net_device *netdev,
 	        struct usb_interface *intf)
@@ -55,6 +57,8 @@ int zd_mac_init(struct zd_mac *mac,
 	softmac_init(ieee80211_priv(netdev));
 	zd_chip_init(&mac->chip, netdev, intf);
 	housekeeping_init(mac);
+	INIT_WORK(&mac->set_multicast_hash_work, set_multicast_hash_handler,
+		  mac);
 	return 0;
 }
 
@@ -136,6 +140,7 @@ out:
 
 void zd_mac_clear(struct zd_mac *mac)
 {
+	flush_workqueue(zd_workqueue);
 	zd_chip_clear(&mac->chip);
 	ZD_ASSERT(!spin_is_locked(&mac->lock));
 	ZD_MEMCLEAR(mac, sizeof(struct zd_mac));
@@ -256,6 +261,42 @@ int zd_mac_set_mac_address(struct net_de
 	return 0;
 }
 
+static void set_multicast_hash_handler(void *mac_ptr)
+{
+	struct zd_mac *mac = mac_ptr;
+	struct zd_mc_hash hash;
+
+	spin_lock_irq(&mac->lock);
+	hash = mac->multicast_hash;
+	spin_unlock_irq(&mac->lock);
+
+	zd_chip_set_multicast_hash(&mac->chip, &hash);
+}
+
+void zd_mac_set_multicast_list(struct net_device *dev)
+{
+	struct zd_mc_hash hash;
+	struct zd_mac *mac = zd_netdev_mac(dev);
+	struct dev_mc_list *mc;
+	unsigned long flags;
+
+	if (dev->flags & (IFF_PROMISC|IFF_ALLMULTI)) {
+		zd_mc_add_all(&hash);
+	} else {
+		zd_mc_clear(&hash);
+		for (mc = dev->mc_list; mc; mc = mc->next) {
+			dev_dbg_f(zd_mac_dev(mac), "mc addr " MAC_FMT "\n",
+				  MAC_ARG(mc->dmi_addr));
+			zd_mc_add_addr(&hash, mc->dmi_addr);
+		}
+	}
+
+	spin_lock_irqsave(&mac->lock, flags);
+	mac->multicast_hash = hash;
+	spin_unlock_irqrestore(&mac->lock, flags);
+	queue_work(zd_workqueue, &mac->set_multicast_hash_work);
+}
+
 int zd_mac_set_regdomain(struct zd_mac *mac, u8 regdomain)
 {
 	int r;
@@ -930,7 +971,8 @@ static int is_data_packet_for_us(struct 
 	}
 
 	return memcmp(hdr->addr1, netdev->dev_addr, ETH_ALEN) == 0 ||
-	       is_multicast_ether_addr(hdr->addr1) ||
+	       (is_multicast_ether_addr(hdr->addr1) &&
+		memcmp(hdr->addr3, netdev->dev_addr, ETH_ALEN) != 0) ||
 	       (netdev->flags & IFF_PROMISC);
 }
 
Index: linux-2.6/drivers/net/wireless/zd1211rw/zd_mac.h
===================================================================
--- linux-2.6.orig/drivers/net/wireless/zd1211rw/zd_mac.h
+++ linux-2.6/drivers/net/wireless/zd1211rw/zd_mac.h
@@ -133,6 +133,8 @@ struct zd_mac {
 	struct iw_statistics iw_stats;
 
 	struct housekeeping housekeeping;
+	struct work_struct set_multicast_hash_work;
+	struct zd_mc_hash multicast_hash;
 	struct work_struct set_rts_cts_work;
 	struct work_struct set_basic_rates_work;
 
@@ -189,6 +191,7 @@ int zd_mac_init_hw(struct zd_mac *mac, u
 int zd_mac_open(struct net_device *netdev);
 int zd_mac_stop(struct net_device *netdev);
 int zd_mac_set_mac_address(struct net_device *dev, void *p);
+void zd_mac_set_multicast_list(struct net_device *netdev);
 
 int zd_mac_rx(struct zd_mac *mac, const u8 *buffer, unsigned int length);
 
Index: linux-2.6/drivers/net/wireless/zd1211rw/zd_netdev.c
===================================================================
--- linux-2.6.orig/drivers/net/wireless/zd1211rw/zd_netdev.c
+++ linux-2.6/drivers/net/wireless/zd1211rw/zd_netdev.c
@@ -242,7 +242,7 @@ struct net_device *zd_netdev_alloc(struc
 	netdev->open = zd_mac_open;
 	netdev->stop = zd_mac_stop;
 	/* netdev->get_stats = */
-	/* netdev->set_multicast_list = */
+	netdev->set_multicast_list = zd_mac_set_multicast_list;
 	netdev->set_mac_address = zd_mac_set_mac_address;
 	netdev->wireless_handlers = &iw_handler_def;
 	/* netdev->ethtool_ops = */

Re: [PATCH] zd1211rw: Support for multicast addresses

[Stephen Hemminger]

On Fri,  1 Dec 2006 00:58:07 +0000 (GMT)
Daniel Drake <dsd@gentoo.org> wrote:

> From: Ulrich Kunitz <kune@deine-taler.de>
> 
> Support for multicast adresses is implemented by supporting the
> set_multicast_list() function of the network device. Address
> filtering is supported by a group hash table in the device.
> 
> This is based on earlier work by Benoit Papillaut. Fixes multicast packet
> reception and ipv6 connectivity:
> http://bugzilla.kernel.org/show_bug.cgi?id=7424
> http://bugzilla.kernel.org/show_bug.cgi?id=7425
> 
> Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
> Signed-off-by: Daniel Drake <dsd@gentoo.org>


Why all the trouble do it off work queue? Is someone calling
set_multicast_list with IRQ's disabled?

Re: [PATCH] zd1211rw: Support for multicast addresses

[Daniel Drake]

Stephen Hemminger wrote:
> Why all the trouble do it off work queue? Is someone calling
> set_multicast_list with IRQ's disabled?

Register I/O involves sleeping, so we need to be in process context.

in_atomic() returns non-zero in the set_multicast_list handler. I 
couldn't tell you which codepath this is in.

Daniel

Re: [PATCH] zd1211rw: Support for multicast addresses

[Ulrich Kunitz]

On 06-11-30 20:57 Daniel Drake wrote:

> Stephen Hemminger wrote:
> >Why all the trouble do it off work queue? Is someone calling
> >set_multicast_list with IRQ's disabled?
> 
> Register I/O involves sleeping, so we need to be in process context.
> 
> in_atomic() returns non-zero in the set_multicast_list handler. I 
> couldn't tell you which codepath this is in.
> 
> Daniel

The function dev_mc_upload() (net/core/dev_mcast.c) calls
netif_tx_lock_bh() which locks the tx spinlock.

The ZD1211 is a USB chip. Register reads will always require
sleeping, if the driver should not spend CPU cycles on polling in
atomic mode. One could implement register writes without waiting
for completion of the writes, but asynchronous error messages for
the writes would make debugging difficult. Additionally hardware
register accesses includes setting a firmware lock, which reqires
a register read. Given all that the driver is always sleeping in
the register access paths. RX and TX paths don't require register
access and work in atomic mode. 

-- 
Uli Kunitz