/******************************************************************************
*
* Copyright(c) 2003 - 2008 Intel Corporation. All rights reserved.
*
* Portions of this file are derived from the ipw3945 project, as well
* as portions of the ieee80211 subsystem header files.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License 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, USA
*
* The full GNU General Public License is included in this distribution in the
* file called LICENSE.
*
* Contact Information:
* James P. Ketrenos <ipw2100-admin@linux.intel.com>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*
*****************************************************************************/
#include <net/mac80211.h>
#include "iwl-eeprom.h"
#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-io.h"
#include "iwl-calib.h"
#include "iwl-helpers.h"
/************************** 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 the NIC. These get
* used not only for Rx frames, but for any command response or notification
* from the NIC. The driver and NIC 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 iwl_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:
*
* iwl_rx_queue_alloc() Allocates rx_free
* iwl_rx_replenish() Replenishes rx_free list from rx_used, and calls
* iwl_rx_queue_restock
* iwl_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 iwl_rx_replenish
*
* -- enable interrupts --
* ISR - iwl_rx() Detach iwl_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 iwl_rx_queue_restock to refill any empty
* slots.
* ...
*
*/
/**
* iwl_rx_queue_space - Return number of free slots available in queue.
*/
int iwl_rx_queue_space(const struct iwl_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;
}
EXPORT_SYMBOL(iwl_rx_queue_space);
/**
* iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue
*/
int iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q)
{
u32 reg = 0;
int ret = 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;
}
ret = iwl_grab_nic_access(priv);
if (ret)
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 ret;
}
EXPORT_SYMBOL(iwl_rx_queue_update_write_ptr);
/**
* iwl_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
*/
static inline __le32 iwl_dma_addr2rbd_ptr(struct iwl_priv *priv,
dma_addr_t dma_addr)
{
return cpu_to_le32((u32)(dma_addr >> 8));
}
/**
* iwl_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.
*/
int iwl_rx_queue_restock(struct iwl_priv *priv)
{
struct iwl_rx_queue *rxq = &priv->rxq;
struct list_head *element;
struct iwl_rx_mem_buffer *rxb;
unsigned long flags;
int write;
int ret = 0;
spin_lock_irqsave(&rxq->lock, flags);
write = rxq->write & ~0x7;
while ((iwl_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 iwl_rx_mem_buffer, list);
list_del(element);
/* Point to Rx buffer via next RBD in circular buffer */
rxq->bd[rxq->write] = iwl_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);
ret = iwl_rx_queue_update_write_ptr(priv, rxq);
}
return ret;
}
EXPORT_SYMBOL(iwl_rx_queue_restock);
/**
* iwl_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 iwl_rx_queue_restock.
* This is called as a scheduled work item (except for during initialization)
*/
void iwl_rx_allocate(struct iwl_priv *priv)
{
struct iwl_rx_queue *rxq = &priv->rxq;
struct list_head *element;
struct iwl_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 iwl_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);
}
EXPORT_SYMBOL(iwl_rx_allocate);
void iwl_rx_replenish(struct iwl_priv *priv)
{
unsigned long flags;
iwl_rx_allocate(priv);
spin_lock_irqsave(&priv->lock, flags);
iwl_rx_queue_restock(priv);
spin_unlock_irqrestore(&priv->lock, flags);
}
EXPORT_SYMBOL(iwl_rx_replenish);
/* 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
*/
void iwl_rx_queue_free(struct iwl_priv *priv, struct iwl_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;
}
EXPORT_SYMBOL(iwl_rx_queue_free);
int iwl_rx_queue_alloc(struct iwl_priv *priv)
{
struct iwl_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;
}
EXPORT_SYMBOL(iwl_rx_queue_alloc);
void iwl_rx_queue_reset(struct iwl_priv *priv, struct iwl_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);
}
EXPORT_SYMBOL(iwl_rx_queue_reset);
int iwl_rx_init(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
{
int ret;
unsigned long flags;
unsigned int rb_size;
spin_lock_irqsave(&priv->lock, flags);
ret = iwl_grab_nic_access(priv);
if (ret) {
spin_unlock_irqrestore(&priv->lock, flags);
return ret;
}
if (priv->cfg->mod_params->amsdu_size_8K)
rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_8K;
else
rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;
/* Stop Rx DMA */
iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
/* Reset driver's Rx queue write index */
iwl_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);
/* Tell device where to find RBD circular buffer in DRAM */
iwl_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_BASE_REG,
rxq->dma_addr >> 8);
/* Tell device where in DRAM to update its Rx status */
iwl_write_direct32(priv, FH_RSCSR_CHNL0_STTS_WPTR_REG,
(priv->shared_phys + priv->rb_closed_offset) >> 4);
/* Enable Rx DMA, enable host interrupt, Rx buffer size 4k, 256 RBDs */
iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG,
FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
rb_size |
/* 0x10 << 4 | */
(RX_QUEUE_SIZE_LOG <<
FH_RCSR_RX_CONFIG_RBDCB_SIZE_BITSHIFT));
/*
* iwl_write32(priv,CSR_INT_COAL_REG,0);
*/
iwl_release_nic_access(priv);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
int iwl_rxq_stop(struct iwl_priv *priv)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
ret = iwl_grab_nic_access(priv);
if (unlikely(ret)) {
spin_unlock_irqrestore(&priv->lock, flags);
return ret;
}
/* stop Rx DMA */
iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
ret = iwl_poll_direct_bit(priv, FH_MEM_RSSR_RX_STATUS_REG,
(1 << 24), 1000);
if (ret < 0)
IWL_ERROR("Can't stop Rx DMA.\n");
iwl_release_nic_access(priv);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
EXPORT_SYMBOL(iwl_rxq_stop);
void iwl_rx_missed_beacon_notif(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
struct iwl4965_missed_beacon_notif *missed_beacon;
missed_beacon = &pkt->u.missed_beacon;
if (le32_to_cpu(missed_beacon->consequtive_missed_beacons) > 5) {
IWL_DEBUG_CALIB("missed bcn cnsq %d totl %d rcd %d expctd %d\n",
le32_to_cpu(missed_beacon->consequtive_missed_beacons),
le32_to_cpu(missed_beacon->total_missed_becons),
le32_to_cpu(missed_beacon->num_recvd_beacons),
le32_to_cpu(missed_beacon->num_expected_beacons));
if (!test_bit(STATUS_SCANNING, &priv->status))
iwl_init_sensitivity(priv);
}
}
EXPORT_SYMBOL(iwl_rx_missed_beacon_notif);
