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linux/drivers/net/wireless/iwlwifi/iwl-rx.c

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/******************************************************************************
*
* Copyright(c) 2003 - 2010 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:
* Intel Linux Wireless <ilw@linux.intel.com>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*
*****************************************************************************/
#include <linux/etherdevice.h>
#include <net/mac80211.h>
#include <asm/unaligned.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
*/
void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q)
{
unsigned long flags;
u32 rx_wrt_ptr_reg = priv->hw_params.rx_wrt_ptr_reg;
u32 reg;
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_DEBUG_INFO(priv, "Rx queue requesting wakeup, GP1 = 0x%x\n",
reg);
iwl_set_bit(priv, CSR_GP_CNTRL,
CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
goto exit_unlock;
}
q->write_actual = (q->write & ~0x7);
iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
/* Else device is assumed to be awake */
} else {
/* Device expects a multiple of 8 */
q->write_actual = (q->write & ~0x7);
iwl_write_direct32(priv, rx_wrt_ptr_reg, q->write_actual);
}
q->need_update = 0;
exit_unlock:
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(iwl_rx_queue_update_write_ptr);
int iwl_rx_queue_alloc(struct iwl_priv *priv)
{
struct iwl_rx_queue *rxq = &priv->rxq;
struct device *dev = &priv->pci_dev->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 = dma_alloc_coherent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr,
GFP_KERNEL);
if (!rxq->bd)
goto err_bd;
rxq->rb_stts = dma_alloc_coherent(dev, sizeof(struct iwl_rb_status),
&rxq->rb_stts_dma, GFP_KERNEL);
if (!rxq->rb_stts)
goto err_rb;
/* 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->write_actual = 0;
rxq->free_count = 0;
rxq->need_update = 0;
return 0;
err_rb:
dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
rxq->dma_addr);
err_bd:
return -ENOMEM;
}
EXPORT_SYMBOL(iwl_rx_queue_alloc);
void iwl_rx_missed_beacon_notif(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = rxb_addr(rxb);
struct iwl_missed_beacon_notif *missed_beacon;
missed_beacon = &pkt->u.missed_beacon;
if (le32_to_cpu(missed_beacon->consecutive_missed_beacons) >
priv->missed_beacon_threshold) {
IWL_DEBUG_CALIB(priv, "missed bcn cnsq %d totl %d rcd %d expctd %d\n",
le32_to_cpu(missed_beacon->consecutive_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);
void iwl_rx_spectrum_measure_notif(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = rxb_addr(rxb);
struct iwl_spectrum_notification *report = &(pkt->u.spectrum_notif);
if (!report->state) {
IWL_DEBUG_11H(priv,
"Spectrum Measure Notification: Start\n");
return;
}
memcpy(&priv->measure_report, report, sizeof(*report));
priv->measurement_status |= MEASUREMENT_READY;
}
EXPORT_SYMBOL(iwl_rx_spectrum_measure_notif);
/* Calculate noise level, based on measurements during network silence just
* before arriving beacon. This measurement can be done only if we know
* exactly when to expect beacons, therefore only when we're associated. */
static void iwl_rx_calc_noise(struct iwl_priv *priv)
{
struct statistics_rx_non_phy *rx_info
= &(priv->statistics.rx.general);
int num_active_rx = 0;
int total_silence = 0;
int bcn_silence_a =
le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
int bcn_silence_b =
le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
int bcn_silence_c =
le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;
int last_rx_noise;
if (bcn_silence_a) {
total_silence += bcn_silence_a;
num_active_rx++;
}
if (bcn_silence_b) {
total_silence += bcn_silence_b;
num_active_rx++;
}
if (bcn_silence_c) {
total_silence += bcn_silence_c;
num_active_rx++;
}
/* Average among active antennas */
if (num_active_rx)
last_rx_noise = (total_silence / num_active_rx) - 107;
else
last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
IWL_DEBUG_CALIB(priv, "inband silence a %u, b %u, c %u, dBm %d\n",
bcn_silence_a, bcn_silence_b, bcn_silence_c,
last_rx_noise);
}
#ifdef CONFIG_IWLWIFI_DEBUG
/*
* based on the assumption of all statistics counter are in DWORD
* FIXME: This function is for debugging, do not deal with
* the case of counters roll-over.
*/
static void iwl_accumulative_statistics(struct iwl_priv *priv,
__le32 *stats)
{
int i;
__le32 *prev_stats;
u32 *accum_stats;
u32 *delta, *max_delta;
prev_stats = (__le32 *)&priv->statistics;
accum_stats = (u32 *)&priv->accum_statistics;
delta = (u32 *)&priv->delta_statistics;
max_delta = (u32 *)&priv->max_delta;
for (i = sizeof(__le32); i < sizeof(struct iwl_notif_statistics);
i += sizeof(__le32), stats++, prev_stats++, delta++,
max_delta++, accum_stats++) {
if (le32_to_cpu(*stats) > le32_to_cpu(*prev_stats)) {
*delta = (le32_to_cpu(*stats) -
le32_to_cpu(*prev_stats));
*accum_stats += *delta;
if (*delta > *max_delta)
*max_delta = *delta;
}
}
/* reset accumulative statistics for "no-counter" type statistics */
priv->accum_statistics.general.temperature =
priv->statistics.general.temperature;
priv->accum_statistics.general.temperature_m =
priv->statistics.general.temperature_m;
priv->accum_statistics.general.ttl_timestamp =
priv->statistics.general.ttl_timestamp;
priv->accum_statistics.tx.tx_power.ant_a =
priv->statistics.tx.tx_power.ant_a;
priv->accum_statistics.tx.tx_power.ant_b =
priv->statistics.tx.tx_power.ant_b;
priv->accum_statistics.tx.tx_power.ant_c =
priv->statistics.tx.tx_power.ant_c;
}
#endif
#define REG_RECALIB_PERIOD (60)
/**
* iwl_good_plcp_health - checks for plcp error.
*
* When the plcp error is exceeding the thresholds, reset the radio
* to improve the throughput.
*/
bool iwl_good_plcp_health(struct iwl_priv *priv,
struct iwl_rx_packet *pkt)
{
bool rc = true;
int combined_plcp_delta;
unsigned int plcp_msec;
unsigned long plcp_received_jiffies;
/*
* check for plcp_err and trigger radio reset if it exceeds
* the plcp error threshold plcp_delta.
*/
plcp_received_jiffies = jiffies;
plcp_msec = jiffies_to_msecs((long) plcp_received_jiffies -
(long) priv->plcp_jiffies);
priv->plcp_jiffies = plcp_received_jiffies;
/*
* check to make sure plcp_msec is not 0 to prevent division
* by zero.
*/
if (plcp_msec) {
combined_plcp_delta =
(le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err) -
le32_to_cpu(priv->statistics.rx.ofdm.plcp_err)) +
(le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err) -
le32_to_cpu(priv->statistics.rx.ofdm_ht.plcp_err));
if ((combined_plcp_delta > 0) &&
((combined_plcp_delta * 100) / plcp_msec) >
priv->cfg->plcp_delta_threshold) {
/*
* if plcp_err exceed the threshold,
* the following data is printed in csv format:
* Text: plcp_err exceeded %d,
* Received ofdm.plcp_err,
* Current ofdm.plcp_err,
* Received ofdm_ht.plcp_err,
* Current ofdm_ht.plcp_err,
* combined_plcp_delta,
* plcp_msec
*/
IWL_DEBUG_RADIO(priv, "plcp_err exceeded %u, "
"%u, %u, %u, %u, %d, %u mSecs\n",
priv->cfg->plcp_delta_threshold,
le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err),
le32_to_cpu(priv->statistics.rx.ofdm.plcp_err),
le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err),
le32_to_cpu(
priv->statistics.rx.ofdm_ht.plcp_err),
combined_plcp_delta, plcp_msec);
rc = false;
}
}
return rc;
}
EXPORT_SYMBOL(iwl_good_plcp_health);
static void iwl_recover_from_statistics(struct iwl_priv *priv,
struct iwl_rx_packet *pkt)
{
if (test_bit(STATUS_EXIT_PENDING, &priv->status))
return;
if (iwl_is_associated(priv)) {
if (priv->cfg->ops->lib->check_ack_health) {
if (!priv->cfg->ops->lib->check_ack_health(
priv, pkt)) {
/*
* low ack count detected
* restart Firmware
*/
IWL_ERR(priv, "low ack count detected, "
"restart firmware\n");
iwl_force_reset(priv, IWL_FW_RESET);
}
} else if (priv->cfg->ops->lib->check_plcp_health) {
if (!priv->cfg->ops->lib->check_plcp_health(
priv, pkt)) {
/*
* high plcp error detected
* reset Radio
*/
iwl_force_reset(priv, IWL_RF_RESET);
}
}
}
}
void iwl_rx_statistics(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
int change;
struct iwl_rx_packet *pkt = rxb_addr(rxb);
IWL_DEBUG_RX(priv, "Statistics notification received (%d vs %d).\n",
(int)sizeof(priv->statistics),
le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK);
change = ((priv->statistics.general.temperature !=
pkt->u.stats.general.temperature) ||
((priv->statistics.flag &
STATISTICS_REPLY_FLG_HT40_MODE_MSK) !=
(pkt->u.stats.flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK)));
#ifdef CONFIG_IWLWIFI_DEBUG
iwl_accumulative_statistics(priv, (__le32 *)&pkt->u.stats);
#endif
iwl_recover_from_statistics(priv, pkt);
memcpy(&priv->statistics, &pkt->u.stats, sizeof(priv->statistics));
set_bit(STATUS_STATISTICS, &priv->status);
/* Reschedule the statistics timer to occur in
* REG_RECALIB_PERIOD seconds to ensure we get a
* thermal update even if the uCode doesn't give
* us one */
mod_timer(&priv->statistics_periodic, jiffies +
msecs_to_jiffies(REG_RECALIB_PERIOD * 1000));
if (unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
(pkt->hdr.cmd == STATISTICS_NOTIFICATION)) {
iwl_rx_calc_noise(priv);
queue_work(priv->workqueue, &priv->run_time_calib_work);
}
if (priv->cfg->ops->lib->temp_ops.temperature && change)
priv->cfg->ops->lib->temp_ops.temperature(priv);
}
EXPORT_SYMBOL(iwl_rx_statistics);
void iwl_reply_statistics(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = rxb_addr(rxb);
if (le32_to_cpu(pkt->u.stats.flag) & UCODE_STATISTICS_CLEAR_MSK) {
#ifdef CONFIG_IWLWIFI_DEBUG
memset(&priv->accum_statistics, 0,
sizeof(struct iwl_notif_statistics));
memset(&priv->delta_statistics, 0,
sizeof(struct iwl_notif_statistics));
memset(&priv->max_delta, 0,
sizeof(struct iwl_notif_statistics));
#endif
IWL_DEBUG_RX(priv, "Statistics have been cleared\n");
}
iwl_rx_statistics(priv, rxb);
}
EXPORT_SYMBOL(iwl_reply_statistics);
/*
* returns non-zero if packet should be dropped
*/
int iwl_set_decrypted_flag(struct iwl_priv *priv,
struct ieee80211_hdr *hdr,
u32 decrypt_res,
struct ieee80211_rx_status *stats)
{
u16 fc = le16_to_cpu(hdr->frame_control);
if (priv->active_rxon.filter_flags & RXON_FILTER_DIS_DECRYPT_MSK)
return 0;
if (!(fc & IEEE80211_FCTL_PROTECTED))
return 0;
IWL_DEBUG_RX(priv, "decrypt_res:0x%x\n", decrypt_res);
switch (decrypt_res & RX_RES_STATUS_SEC_TYPE_MSK) {
case RX_RES_STATUS_SEC_TYPE_TKIP:
/* The uCode has got a bad phase 1 Key, pushes the packet.
* Decryption will be done in SW. */
if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
RX_RES_STATUS_BAD_KEY_TTAK)
break;
case RX_RES_STATUS_SEC_TYPE_WEP:
if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
RX_RES_STATUS_BAD_ICV_MIC) {
/* bad ICV, the packet is destroyed since the
* decryption is inplace, drop it */
IWL_DEBUG_RX(priv, "Packet destroyed\n");
return -1;
}
case RX_RES_STATUS_SEC_TYPE_CCMP:
if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
RX_RES_STATUS_DECRYPT_OK) {
IWL_DEBUG_RX(priv, "hw decrypt successfully!!!\n");
stats->flag |= RX_FLAG_DECRYPTED;
}
break;
default:
break;
}
return 0;
}
EXPORT_SYMBOL(iwl_set_decrypted_flag);
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