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