uwb: add the WiMedia LLC Protocol stack

Add the generic code for the WiMedia Logical Link Control Protocol (WLP).

This has been split into several patches for easier review.

core (this patch):
  - everything else

messages:
  - WLP message construction/decode

wss:
  - Wireless Service Set support

build-system:
  - Kconfig and Kbuild files

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 449 insertions, 0 deletions

diff --git a/drivers/uwb/wlp/eda.c b/drivers/uwb/wlp/eda.c
new file mode 100644
index 00000000000..cdfe8dfc434
--- /dev/null
+++ b/drivers/uwb/wlp/eda.c
@@ -0,0 +1,449 @@
+/*
+ * WUSB Wire Adapter: WLP interface
+ * Ethernet to device address cache
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * We need to be able to map ethernet addresses to device addresses
+ * and back because there is not explicit relationship between the eth
+ * addresses used in the ETH frames and the device addresses (no, it
+ * would not have been simpler to force as ETH address the MBOA MAC
+ * address...no, not at all :).
+ *
+ * A device has one MBOA MAC address and one device address. It is possible
+ * for a device to have more than one virtual MAC address (although a
+ * virtual address can be the same as the MBOA MAC address). The device
+ * address is guaranteed to be unique among the devices in the extended
+ * beacon group (see ECMA 17.1.1). We thus use the device address as index
+ * to this cache. We do allow searching based on virtual address as this
+ * is how Ethernet frames will be addressed.
+ *
+ * We need to support virtual EUI-48. Although, right now the virtual
+ * EUI-48 will always be the same as the MAC SAP address. The EDA cache
+ * entry thus contains a MAC SAP address as well as the virtual address
+ * (used to map the network stack address to a neighbor). When we move
+ * to support more than one virtual MAC on a host then this organization
+ * will have to change. Perhaps a neighbor has a list of WSSs, each with a
+ * tag and virtual EUI-48.
+ *
+ * On data transmission
+ * it is used to determine if the neighbor is connected and what WSS it
+ * belongs to. With this we know what tag to add to the WLP frame. Storing
+ * the WSS in the EDA cache may be overkill because we only support one
+ * WSS. Hopefully we will support more than one WSS at some point.
+ * On data reception it is used to determine the WSS based on
+ * the tag and address of the transmitting neighbor.
+ */
+
+#define D_LOCAL 5
+#include <linux/netdevice.h>
+#include <linux/uwb/debug.h>
+#include <linux/etherdevice.h>
+#include <linux/wlp.h>
+#include "wlp-internal.h"
+
+
+/* FIXME: cache is not purged, only on device close */
+
+/* FIXME: does not scale, change to dynamic array */
+
+/*
+ * Initialize the EDA cache
+ *
+ * @returns 0 if ok, < 0 errno code on error
+ *
+ * Call when the interface is being brought up
+ *
+ * NOTE: Keep it as a separate function as the implementation will
+ *       change and be more complex.
+ */
+void wlp_eda_init(struct wlp_eda *eda)
+{
+	INIT_LIST_HEAD(&eda->cache);
+	spin_lock_init(&eda->lock);
+}
+
+/*
+ * Release the EDA cache
+ *
+ * @returns 0 if ok, < 0 errno code on error
+ *
+ * Called when the interface is brought down
+ */
+void wlp_eda_release(struct wlp_eda *eda)
+{
+	unsigned long flags;
+	struct wlp_eda_node *itr, *next;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry_safe(itr, next, &eda->cache, list_node) {
+		list_del(&itr->list_node);
+		kfree(itr);
+	}
+	spin_unlock_irqrestore(&eda->lock, flags);
+}
+
+/*
+ * Add an address mapping
+ *
+ * @returns 0 if ok, < 0 errno code on error
+ *
+ * An address mapping is initially created when the neighbor device is seen
+ * for the first time (it is "onair"). At this time the neighbor is not
+ * connected or associated with a WSS so we only populate the Ethernet and
+ * Device address fields.
+ *
+ */
+int wlp_eda_create_node(struct wlp_eda *eda,
+			const unsigned char eth_addr[ETH_ALEN],
+			const struct uwb_dev_addr *dev_addr)
+{
+	int result = 0;
+	struct wlp_eda_node *itr;
+	unsigned long flags;
+
+	BUG_ON(dev_addr == NULL || eth_addr == NULL);
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry(itr, &eda->cache, list_node) {
+		if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
+			printk(KERN_ERR "EDA cache already contains entry "
+			       "for neighbor %02x:%02x\n",
+			       dev_addr->data[1], dev_addr->data[0]);
+			result = -EEXIST;
+			goto out_unlock;
+		}
+	}
+	itr = kzalloc(sizeof(*itr), GFP_ATOMIC);
+	if (itr != NULL) {
+		memcpy(itr->eth_addr, eth_addr, sizeof(itr->eth_addr));
+		itr->dev_addr = *dev_addr;
+		list_add(&itr->list_node, &eda->cache);
+	} else
+		result = -ENOMEM;
+out_unlock:
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+
+/*
+ * Remove entry from EDA cache
+ *
+ * This is done when the device goes off air.
+ */
+void wlp_eda_rm_node(struct wlp_eda *eda, const struct uwb_dev_addr *dev_addr)
+{
+	struct wlp_eda_node *itr, *next;
+	unsigned long flags;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry_safe(itr, next, &eda->cache, list_node) {
+		if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
+			list_del(&itr->list_node);
+			kfree(itr);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&eda->lock, flags);
+}
+
+/*
+ * Update an address mapping
+ *
+ * @returns 0 if ok, < 0 errno code on error
+ */
+int wlp_eda_update_node(struct wlp_eda *eda,
+			const struct uwb_dev_addr *dev_addr,
+			struct wlp_wss *wss,
+			const unsigned char virt_addr[ETH_ALEN],
+			const u8 tag, const enum wlp_wss_connect state)
+{
+	int result = -ENOENT;
+	struct wlp_eda_node *itr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry(itr, &eda->cache, list_node) {
+		if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
+			/* Found it, update it */
+			itr->wss = wss;
+			memcpy(itr->virt_addr, virt_addr,
+			       sizeof(itr->virt_addr));
+			itr->tag = tag;
+			itr->state = state;
+			result = 0;
+			goto out_unlock;
+		}
+	}
+	/* Not found */
+out_unlock:
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+
+/*
+ * Update only state field of an address mapping
+ *
+ * @returns 0 if ok, < 0 errno code on error
+ */
+int wlp_eda_update_node_state(struct wlp_eda *eda,
+			      const struct uwb_dev_addr *dev_addr,
+			      const enum wlp_wss_connect state)
+{
+	int result = -ENOENT;
+	struct wlp_eda_node *itr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry(itr, &eda->cache, list_node) {
+		if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
+			/* Found it, update it */
+			itr->state = state;
+			result = 0;
+			goto out_unlock;
+		}
+	}
+	/* Not found */
+out_unlock:
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+
+/*
+ * Return contents of EDA cache entry
+ *
+ * @dev_addr: index to EDA cache
+ * @eda_entry: pointer to where contents of EDA cache will be copied
+ */
+int wlp_copy_eda_node(struct wlp_eda *eda, struct uwb_dev_addr *dev_addr,
+		      struct wlp_eda_node *eda_entry)
+{
+	int result = -ENOENT;
+	struct wlp_eda_node *itr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry(itr, &eda->cache, list_node) {
+		if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
+			*eda_entry = *itr;
+			result = 0;
+			goto out_unlock;
+		}
+	}
+	/* Not found */
+out_unlock:
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+
+/*
+ * Execute function for every element in the cache
+ *
+ * @function: function to execute on element of cache (must be atomic)
+ * @priv:     private data of function
+ * @returns:  result of first function that failed, or last function
+ *            executed if no function failed.
+ *
+ * Stop executing when function returns error for any element in cache.
+ *
+ * IMPORTANT: We are using a spinlock here: the function executed on each
+ * element has to be atomic.
+ */
+int wlp_eda_for_each(struct wlp_eda *eda, wlp_eda_for_each_f function,
+		     void *priv)
+{
+	int result = 0;
+	struct wlp *wlp = container_of(eda, struct wlp, eda);
+	struct wlp_eda_node *entry;
+	unsigned long flags;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry(entry, &eda->cache, list_node) {
+		result = (*function)(wlp, entry, priv);
+		if (result < 0)
+			break;
+	}
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+
+/*
+ * Execute function for single element in the cache (return dev addr)
+ *
+ * @virt_addr: index into EDA cache used to determine which element to
+ *             execute the function on
+ * @dev_addr: device address of element in cache will be returned using
+ *            @dev_addr
+ * @function: function to execute on element of cache (must be atomic)
+ * @priv:     private data of function
+ * @returns:  result of function
+ *
+ * IMPORTANT: We are using a spinlock here: the function executed on the
+ * element has to be atomic.
+ */
+int wlp_eda_for_virtual(struct wlp_eda *eda,
+			const unsigned char virt_addr[ETH_ALEN],
+			struct uwb_dev_addr *dev_addr,
+			wlp_eda_for_each_f function,
+			void *priv)
+{
+	int result = 0;
+	struct wlp *wlp = container_of(eda, struct wlp, eda);
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	struct wlp_eda_node *itr;
+	unsigned long flags;
+	int found = 0;
+
+	spin_lock_irqsave(&eda->lock, flags);
+	list_for_each_entry(itr, &eda->cache, list_node) {
+		if (!memcmp(itr->virt_addr, virt_addr,
+			   sizeof(itr->virt_addr))) {
+			d_printf(6, dev, "EDA: looking for "
+			       "%02x:%02x:%02x:%02x:%02x:%02x hit %02x:%02x "
+			       "wss %p tag 0x%02x state %u\n",
+			       virt_addr[0], virt_addr[1],
+			       virt_addr[2], virt_addr[3],
+			       virt_addr[4], virt_addr[5],
+			       itr->dev_addr.data[1],
+			       itr->dev_addr.data[0], itr->wss,
+			       itr->tag, itr->state);
+			result = (*function)(wlp, itr, priv);
+			*dev_addr = itr->dev_addr;
+			found = 1;
+			break;
+		} else
+			d_printf(6, dev, "EDA: looking for "
+			       "%02x:%02x:%02x:%02x:%02x:%02x "
+			       "against "
+			       "%02x:%02x:%02x:%02x:%02x:%02x miss\n",
+			       virt_addr[0], virt_addr[1],
+			       virt_addr[2], virt_addr[3],
+			       virt_addr[4], virt_addr[5],
+			       itr->virt_addr[0], itr->virt_addr[1],
+			       itr->virt_addr[2], itr->virt_addr[3],
+			       itr->virt_addr[4], itr->virt_addr[5]);
+	}
+	if (!found) {
+		if (printk_ratelimit())
+			dev_err(dev, "EDA: Eth addr %02x:%02x:%02x"
+				":%02x:%02x:%02x not found.\n",
+				virt_addr[0], virt_addr[1],
+				virt_addr[2], virt_addr[3],
+				virt_addr[4], virt_addr[5]);
+		result = -ENODEV;
+	}
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+
+static const char *__wlp_wss_connect_state[] = { "WLP_WSS_UNCONNECTED",
+					  "WLP_WSS_CONNECTED",
+					  "WLP_WSS_CONNECT_FAILED",
+};
+
+static const char *wlp_wss_connect_state_str(unsigned id)
+{
+	if (id >= ARRAY_SIZE(__wlp_wss_connect_state))
+		return "unknown WSS connection state";
+	return __wlp_wss_connect_state[id];
+}
+
+/*
+ * View EDA cache from user space
+ *
+ * A debugging feature to give user visibility into the EDA cache. Also
+ * used to display members of WSS to user (called from wlp_wss_members_show())
+ */
+ssize_t wlp_eda_show(struct wlp *wlp, char *buf)
+{
+	ssize_t result = 0;
+	struct wlp_eda_node *entry;
+	unsigned long flags;
+	struct wlp_eda *eda = &wlp->eda;
+	spin_lock_irqsave(&eda->lock, flags);
+	result = scnprintf(buf, PAGE_SIZE, "#eth_addr dev_addr wss_ptr "
+			   "tag state virt_addr\n");
+	list_for_each_entry(entry, &eda->cache, list_node) {
+		result += scnprintf(buf + result, PAGE_SIZE - result,
+				    "%02x:%02x:%02x:%02x:%02x:%02x %02x:%02x "
+				    "%p 0x%02x %s "
+				    "%02x:%02x:%02x:%02x:%02x:%02x\n",
+				    entry->eth_addr[0], entry->eth_addr[1],
+				    entry->eth_addr[2], entry->eth_addr[3],
+				    entry->eth_addr[4], entry->eth_addr[5],
+				    entry->dev_addr.data[1],
+				    entry->dev_addr.data[0], entry->wss,
+				    entry->tag,
+				    wlp_wss_connect_state_str(entry->state),
+				    entry->virt_addr[0], entry->virt_addr[1],
+				    entry->virt_addr[2], entry->virt_addr[3],
+				    entry->virt_addr[4], entry->virt_addr[5]);
+		if (result >= PAGE_SIZE)
+			break;
+	}
+	spin_unlock_irqrestore(&eda->lock, flags);
+	return result;
+}
+EXPORT_SYMBOL_GPL(wlp_eda_show);
+
+/*
+ * Add new EDA cache entry based on user input in sysfs
+ *
+ * Should only be used for debugging.
+ *
+ * The WSS is assumed to be the only WSS supported. This needs to be
+ * redesigned when we support more than one WSS.
+ */
+ssize_t wlp_eda_store(struct wlp *wlp, const char *buf, size_t size)
+{
+	ssize_t result;
+	struct wlp_eda *eda = &wlp->eda;
+	u8 eth_addr[6];
+	struct uwb_dev_addr dev_addr;
+	u8 tag;
+	unsigned state;
+
+	result = sscanf(buf, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx "
+			"%02hhx:%02hhx %02hhx %u\n",
+			&eth_addr[0], &eth_addr[1],
+			&eth_addr[2], &eth_addr[3],
+			&eth_addr[4], &eth_addr[5],
+			&dev_addr.data[1], &dev_addr.data[0], &tag, &state);
+	switch (result) {
+	case 6: /* no dev addr specified -- remove entry NOT IMPLEMENTED */
+		/*result = wlp_eda_rm(eda, eth_addr, &dev_addr);*/
+		result = -ENOSYS;
+		break;
+	case 10:
+		state = state >= 1 ? 1 : 0;
+		result = wlp_eda_create_node(eda, eth_addr, &dev_addr);
+		if (result < 0 && result != -EEXIST)
+			goto error;
+		/* Set virtual addr to be same as MAC */
+		result = wlp_eda_update_node(eda, &dev_addr, &wlp->wss,
+					     eth_addr, tag, state);
+		if (result < 0)
+			goto error;
+		break;
+	default: /* bad format */
+		result = -EINVAL;
+	}
+error:
+	return result < 0 ? result : size;
+}
+EXPORT_SYMBOL_GPL(wlp_eda_store);