- rxb->skb = NULL;
-
- iwl4965_tx_queue_reclaim(priv, txq_id, index);
-
- if (!(cmd->meta.flags & CMD_ASYNC)) {
- clear_bit(STATUS_HCMD_ACTIVE, &priv->status);
- wake_up_interruptible(&priv->wait_command_queue);
- }
-}
-
-/************************** RX-FUNCTIONS ****************************/
-/*
- * Rx theory of operation
- *
- * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
- * each of which point to Receive Buffers to be filled by 4965. These get
- * used not only for Rx frames, but for any command response or notification
- * from the 4965. The driver and 4965 manage the Rx buffers by means
- * of indexes into the circular buffer.
- *
- * Rx Queue Indexes
- * The host/firmware share two index registers for managing the Rx buffers.
- *
- * The READ index maps to the first position that the firmware may be writing
- * to -- the driver can read up to (but not including) this position and get
- * good data.
- * The READ index is managed by the firmware once the card is enabled.
- *
- * The WRITE index maps to the last position the driver has read from -- the
- * position preceding WRITE is the last slot the firmware can place a packet.
- *
- * The queue is empty (no good data) if WRITE = READ - 1, and is full if
- * WRITE = READ.
- *
- * During initialization, the host sets up the READ queue position to the first
- * INDEX position, and WRITE to the last (READ - 1 wrapped)
- *
- * When the firmware places a packet in a buffer, it will advance the READ index
- * and fire the RX interrupt. The driver can then query the READ index and
- * process as many packets as possible, moving the WRITE index forward as it
- * resets the Rx queue buffers with new memory.
- *
- * The management in the driver is as follows:
- * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When
- * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
- * to replenish the iwl->rxq->rx_free.
- * + In iwl4965_rx_replenish (scheduled) if 'processed' != 'read' then the
- * iwl->rxq is replenished and the READ INDEX is updated (updating the
- * 'processed' and 'read' driver indexes as well)
- * + A received packet is processed and handed to the kernel network stack,
- * detached from the iwl->rxq. The driver 'processed' index is updated.
- * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
- * list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
- * INDEX is not incremented and iwl->status(RX_STALLED) is set. If there
- * were enough free buffers and RX_STALLED is set it is cleared.
- *
- *
- * Driver sequence:
- *
- * iwl4965_rx_queue_alloc() Allocates rx_free
- * iwl4965_rx_replenish() Replenishes rx_free list from rx_used, and calls
- * iwl4965_rx_queue_restock
- * iwl4965_rx_queue_restock() Moves available buffers from rx_free into Rx
- * queue, updates firmware pointers, and updates
- * the WRITE index. If insufficient rx_free buffers
- * are available, schedules iwl4965_rx_replenish
- *
- * -- enable interrupts --
- * ISR - iwl4965_rx() Detach iwl4965_rx_mem_buffers from pool up to the
- * READ INDEX, detaching the SKB from the pool.
- * Moves the packet buffer from queue to rx_used.
- * Calls iwl4965_rx_queue_restock to refill any empty
- * slots.
- * ...
- *
- */
-
-/**
- * iwl4965_rx_queue_space - Return number of free slots available in queue.
- */
-static int iwl4965_rx_queue_space(const struct iwl4965_rx_queue *q)
-{
- int s = q->read - q->write;
- if (s <= 0)
- s += RX_QUEUE_SIZE;
- /* keep some buffer to not confuse full and empty queue */
- s -= 2;
- if (s < 0)
- s = 0;
- return s;
-}
-
-/**
- * iwl4965_rx_queue_update_write_ptr - Update the write pointer for the RX queue
- */
-int iwl4965_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl4965_rx_queue *q)
-{
- u32 reg = 0;
- int rc = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&q->lock, flags);
-
- if (q->need_update == 0)
- goto exit_unlock;
-
- /* If power-saving is in use, make sure device is awake */
- if (test_bit(STATUS_POWER_PMI, &priv->status)) {
- reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
-
- if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
- iwl_set_bit(priv, CSR_GP_CNTRL,
- CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
- goto exit_unlock;
- }
-
- rc = iwl_grab_nic_access(priv);
- if (rc)
- goto exit_unlock;
-
- /* Device expects a multiple of 8 */
- iwl_write_direct32(priv, FH_RSCSR_CHNL0_WPTR,
- q->write & ~0x7);
- iwl_release_nic_access(priv);
-
- /* Else device is assumed to be awake */
- } else
- /* Device expects a multiple of 8 */
- iwl_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7);
-
-
- q->need_update = 0;
-
- exit_unlock:
- spin_unlock_irqrestore(&q->lock, flags);
- return rc;
-}
-
-/**
- * iwl4965_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
- */
-static inline __le32 iwl4965_dma_addr2rbd_ptr(struct iwl_priv *priv,
- dma_addr_t dma_addr)
-{
- return cpu_to_le32((u32)(dma_addr >> 8));
-}
-
-
-/**
- * iwl4965_rx_queue_restock - refill RX queue from pre-allocated pool
- *
- * If there are slots in the RX queue that need to be restocked,
- * and we have free pre-allocated buffers, fill the ranks as much
- * as we can, pulling from rx_free.
- *
- * This moves the 'write' index forward to catch up with 'processed', and
- * also updates the memory address in the firmware to reference the new
- * target buffer.
- */
-static int iwl4965_rx_queue_restock(struct iwl_priv *priv)
-{
- struct iwl4965_rx_queue *rxq = &priv->rxq;
- struct list_head *element;
- struct iwl4965_rx_mem_buffer *rxb;
- unsigned long flags;
- int write, rc;
-
- spin_lock_irqsave(&rxq->lock, flags);
- write = rxq->write & ~0x7;
- while ((iwl4965_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
- /* Get next free Rx buffer, remove from free list */
- element = rxq->rx_free.next;
- rxb = list_entry(element, struct iwl4965_rx_mem_buffer, list);
- list_del(element);
-
- /* Point to Rx buffer via next RBD in circular buffer */
- rxq->bd[rxq->write] = iwl4965_dma_addr2rbd_ptr(priv, rxb->dma_addr);
- rxq->queue[rxq->write] = rxb;
- rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
- rxq->free_count--;
- }
- spin_unlock_irqrestore(&rxq->lock, flags);
- /* If the pre-allocated buffer pool is dropping low, schedule to
- * refill it */
- if (rxq->free_count <= RX_LOW_WATERMARK)
- queue_work(priv->workqueue, &priv->rx_replenish);
-
-
- /* If we've added more space for the firmware to place data, tell it.
- * Increment device's write pointer in multiples of 8. */
- if ((write != (rxq->write & ~0x7))
- || (abs(rxq->write - rxq->read) > 7)) {
- spin_lock_irqsave(&rxq->lock, flags);
- rxq->need_update = 1;
- spin_unlock_irqrestore(&rxq->lock, flags);
- rc = iwl4965_rx_queue_update_write_ptr(priv, rxq);
- if (rc)
- return rc;
- }
-
- return 0;
-}
-
-/**
- * iwl4965_rx_replenish - Move all used packet from rx_used to rx_free
- *
- * When moving to rx_free an SKB is allocated for the slot.
- *
- * Also restock the Rx queue via iwl4965_rx_queue_restock.
- * This is called as a scheduled work item (except for during initialization)
- */
-static void iwl4965_rx_allocate(struct iwl_priv *priv)
-{
- struct iwl4965_rx_queue *rxq = &priv->rxq;
- struct list_head *element;
- struct iwl4965_rx_mem_buffer *rxb;
- unsigned long flags;
- spin_lock_irqsave(&rxq->lock, flags);
- while (!list_empty(&rxq->rx_used)) {
- element = rxq->rx_used.next;
- rxb = list_entry(element, struct iwl4965_rx_mem_buffer, list);
-
- /* Alloc a new receive buffer */
- rxb->skb =
- alloc_skb(priv->hw_params.rx_buf_size,
- __GFP_NOWARN | GFP_ATOMIC);
- if (!rxb->skb) {
- if (net_ratelimit())
- printk(KERN_CRIT DRV_NAME
- ": Can not allocate SKB buffers\n");
- /* We don't reschedule replenish work here -- we will
- * call the restock method and if it still needs
- * more buffers it will schedule replenish */
- break;
- }
- priv->alloc_rxb_skb++;
- list_del(element);
-
- /* Get physical address of RB/SKB */
- rxb->dma_addr =
- pci_map_single(priv->pci_dev, rxb->skb->data,
- priv->hw_params.rx_buf_size, PCI_DMA_FROMDEVICE);
- list_add_tail(&rxb->list, &rxq->rx_free);
- rxq->free_count++;
- }
- spin_unlock_irqrestore(&rxq->lock, flags);
-}
-
-/*
- * this should be called while priv->lock is locked
-*/
-static void __iwl4965_rx_replenish(void *data)
-{
- struct iwl_priv *priv = data;
-
- iwl4965_rx_allocate(priv);
- iwl4965_rx_queue_restock(priv);
-}
-
-
-void iwl4965_rx_replenish(void *data)
-{
- struct iwl_priv *priv = data;
- unsigned long flags;
-
- iwl4965_rx_allocate(priv);
-
- spin_lock_irqsave(&priv->lock, flags);
- iwl4965_rx_queue_restock(priv);
- spin_unlock_irqrestore(&priv->lock, flags);
-}
-
-/* Assumes that the skb field of the buffers in 'pool' is kept accurate.
- * If an SKB has been detached, the POOL needs to have its SKB set to NULL
- * This free routine walks the list of POOL entries and if SKB is set to
- * non NULL it is unmapped and freed
- */
-static void iwl4965_rx_queue_free(struct iwl_priv *priv, struct iwl4965_rx_queue *rxq)
-{
- int i;
- for (i = 0; i < RX_QUEUE_SIZE + RX_FREE_BUFFERS; i++) {
- if (rxq->pool[i].skb != NULL) {
- pci_unmap_single(priv->pci_dev,
- rxq->pool[i].dma_addr,
- priv->hw_params.rx_buf_size,
- PCI_DMA_FROMDEVICE);
- dev_kfree_skb(rxq->pool[i].skb);
- }
- }
-
- pci_free_consistent(priv->pci_dev, 4 * RX_QUEUE_SIZE, rxq->bd,
- rxq->dma_addr);
- rxq->bd = NULL;
-}
-
-int iwl4965_rx_queue_alloc(struct iwl_priv *priv)
-{
- struct iwl4965_rx_queue *rxq = &priv->rxq;
- struct pci_dev *dev = priv->pci_dev;
- int i;
-
- spin_lock_init(&rxq->lock);
- INIT_LIST_HEAD(&rxq->rx_free);
- INIT_LIST_HEAD(&rxq->rx_used);
-
- /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
- rxq->bd = pci_alloc_consistent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr);
- if (!rxq->bd)
- return -ENOMEM;
-
- /* Fill the rx_used queue with _all_ of the Rx buffers */
- for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
- list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
-
- /* Set us so that we have processed and used all buffers, but have
- * not restocked the Rx queue with fresh buffers */
- rxq->read = rxq->write = 0;
- rxq->free_count = 0;
- rxq->need_update = 0;
- return 0;
-}
-
-void iwl4965_rx_queue_reset(struct iwl_priv *priv, struct iwl4965_rx_queue *rxq)
-{
- unsigned long flags;
- int i;
- spin_lock_irqsave(&rxq->lock, flags);
- INIT_LIST_HEAD(&rxq->rx_free);
- INIT_LIST_HEAD(&rxq->rx_used);
- /* Fill the rx_used queue with _all_ of the Rx buffers */
- for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) {
- /* In the reset function, these buffers may have been allocated
- * to an SKB, so we need to unmap and free potential storage */
- if (rxq->pool[i].skb != NULL) {
- pci_unmap_single(priv->pci_dev,
- rxq->pool[i].dma_addr,
- priv->hw_params.rx_buf_size,
- PCI_DMA_FROMDEVICE);
- priv->alloc_rxb_skb--;
- dev_kfree_skb(rxq->pool[i].skb);
- rxq->pool[i].skb = NULL;
- }
- list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
- }
-
- /* Set us so that we have processed and used all buffers, but have
- * not restocked the Rx queue with fresh buffers */
- rxq->read = rxq->write = 0;
- rxq->free_count = 0;
- spin_unlock_irqrestore(&rxq->lock, flags);
-}
-
-/* Convert linear signal-to-noise ratio into dB */
-static u8 ratio2dB[100] = {
-/* 0 1 2 3 4 5 6 7 8 9 */
- 0, 0, 6, 10, 12, 14, 16, 17, 18, 19, /* 00 - 09 */
- 20, 21, 22, 22, 23, 23, 24, 25, 26, 26, /* 10 - 19 */
- 26, 26, 26, 27, 27, 28, 28, 28, 29, 29, /* 20 - 29 */
- 29, 30, 30, 30, 31, 31, 31, 31, 32, 32, /* 30 - 39 */
- 32, 32, 32, 33, 33, 33, 33, 33, 34, 34, /* 40 - 49 */
- 34, 34, 34, 34, 35, 35, 35, 35, 35, 35, /* 50 - 59 */
- 36, 36, 36, 36, 36, 36, 36, 37, 37, 37, /* 60 - 69 */
- 37, 37, 37, 37, 37, 38, 38, 38, 38, 38, /* 70 - 79 */
- 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, /* 80 - 89 */
- 39, 39, 39, 39, 39, 40, 40, 40, 40, 40 /* 90 - 99 */
-};
-
-/* Calculates a relative dB value from a ratio of linear
- * (i.e. not dB) signal levels.
- * Conversion assumes that levels are voltages (20*log), not powers (10*log). */
-int iwl4965_calc_db_from_ratio(int sig_ratio)
-{
- /* 1000:1 or higher just report as 60 dB */
- if (sig_ratio >= 1000)
- return 60;
-
- /* 100:1 or higher, divide by 10 and use table,
- * add 20 dB to make up for divide by 10 */
- if (sig_ratio >= 100)
- return (20 + (int)ratio2dB[sig_ratio/10]);
-
- /* We shouldn't see this */
- if (sig_ratio < 1)
- return 0;
-
- /* Use table for ratios 1:1 - 99:1 */
- return (int)ratio2dB[sig_ratio];
-}
-
-#define PERFECT_RSSI (-20) /* dBm */
-#define WORST_RSSI (-95) /* dBm */
-#define RSSI_RANGE (PERFECT_RSSI - WORST_RSSI)
-
-/* Calculate an indication of rx signal quality (a percentage, not dBm!).
- * See http://www.ces.clemson.edu/linux/signal_quality.shtml for info
- * about formulas used below. */
-int iwl4965_calc_sig_qual(int rssi_dbm, int noise_dbm)
-{
- int sig_qual;
- int degradation = PERFECT_RSSI - rssi_dbm;
-
- /* If we get a noise measurement, use signal-to-noise ratio (SNR)
- * as indicator; formula is (signal dbm - noise dbm).
- * SNR at or above 40 is a great signal (100%).
- * Below that, scale to fit SNR of 0 - 40 dB within 0 - 100% indicator.
- * Weakest usable signal is usually 10 - 15 dB SNR. */
- if (noise_dbm) {
- if (rssi_dbm - noise_dbm >= 40)
- return 100;
- else if (rssi_dbm < noise_dbm)
- return 0;
- sig_qual = ((rssi_dbm - noise_dbm) * 5) / 2;