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linux/drivers/net/wireless/iwlwifi/iwl-rx.c
Johannes Berg 4018517a1a iwlagn: fix RX skb alignment 
So I dug deeper into the DMA problems I had with iwlagn and a kind soul
helped me in that he said something about pci-e alignment and mentioned
the iwl_rx_allocate function to check for crossing 4KB boundaries. Since
there's 8KB A-MPDU support, crossing 4k boundaries didn't seem like
something the device would fail with, but when I looked into the
function for a minute anyway I stumbled over this little gem:

	BUG_ON(rxb->dma_addr & (~DMA_BIT_MASK(36) & 0xff));

Clearly, that is a totally bogus check, one would hope the compiler
removes it entirely. (Think about it)

After fixing it, I obviously ran into it, nothing guarantees the
alignment the way you want it,  because of the way skbs and their
headroom are allocated. I won't explain that here nor double-check that
I'm right, that goes beyond what most of the CC'ed people care about.

So then I came up with the patch below, and so far my system has
survived minutes with 64K pages, when it would previously fail in
seconds. And I haven't seen a single instance of the TX bug either. But
when you see the patch it'll be pretty obvious to you why.

This should fix the following reported kernel bugs:

http://bugzilla.kernel.org/show_bug.cgi?id=11596
http://bugzilla.kernel.org/show_bug.cgi?id=11393
http://bugzilla.kernel.org/show_bug.cgi?id=11983

I haven't checked if there are any elsewhere, but I suppose RHBZ will
have a few instances too...

I'd like to ask anyone who is CC'ed (those are people I know ran into
the bug) to try this patch.

I am convinced that this patch is correct in spirit, but I haven't
understood why, for example, there are so many unmap calls. I'm not
entirely convinced that this is the only bug leading to the TX reply
errors.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-11-18 17:26:26 -05:00

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/******************************************************************************
*
* 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 <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
*/
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->aligned_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 + 256,
__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->real_dma_addr = pci_map_single(
priv->pci_dev,
rxb->skb->data,
priv->hw_params.rx_buf_size + 256,
PCI_DMA_FROMDEVICE);
/* dma address must be no more than 36 bits */
BUG_ON(rxb->real_dma_addr & ~DMA_BIT_MASK(36));
/* and also 256 byte aligned! */
rxb->aligned_dma_addr = ALIGN(rxb->real_dma_addr, 256);
skb_reserve(rxb->skb, rxb->aligned_dma_addr - rxb->real_dma_addr);
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].real_dma_addr,
priv->hw_params.rx_buf_size + 256,
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].real_dma_addr,
priv->hw_params.rx_buf_size + 256,
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;
u32 rb_size;
const u32 rfdnlog = RX_QUEUE_SIZE_LOG; /* 256 RBDs */
const u32 rb_timeout = 0; /* FIXME: RX_RB_TIMEOUT why this stalls RX */
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,
(u32)(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
* FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY is set becuase of HW bug in
* the credit mechanism in 5000 HW RX FIFO
* Direct rx interrupts to hosts
* Rx buffer size 4 or 8k
* RB timeout 0x10
* 256 RBDs
*/
iwl_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG,
FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY |
FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
rb_size|
(rb_timeout << FH_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS)|
(rfdnlog << FH_RCSR_RX_CONFIG_RBDCB_SIZE_POS));
iwl_release_nic_access(priv);
iwl_write32(priv, CSR_INT_COALESCING, 0x40);
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);
int iwl_rx_agg_start(struct iwl_priv *priv, const u8 *addr, int tid, u16 ssn)
{
unsigned long flags;
int sta_id;
sta_id = iwl_find_station(priv, addr);
if (sta_id == IWL_INVALID_STATION)
return -ENXIO;
spin_lock_irqsave(&priv->sta_lock, flags);
priv->stations[sta_id].sta.station_flags_msk = 0;
priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_ADDBA_TID_MSK;
priv->stations[sta_id].sta.add_immediate_ba_tid = (u8)tid;
priv->stations[sta_id].sta.add_immediate_ba_ssn = cpu_to_le16(ssn);
priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
spin_unlock_irqrestore(&priv->sta_lock, flags);
return iwl_send_add_sta(priv, &priv->stations[sta_id].sta,
CMD_ASYNC);
}
EXPORT_SYMBOL(iwl_rx_agg_start);
int iwl_rx_agg_stop(struct iwl_priv *priv, const u8 *addr, int tid)
{
unsigned long flags;
int sta_id;
sta_id = iwl_find_station(priv, addr);
if (sta_id == IWL_INVALID_STATION)
return -ENXIO;
spin_lock_irqsave(&priv->sta_lock, flags);
priv->stations[sta_id].sta.station_flags_msk = 0;
priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_DELBA_TID_MSK;
priv->stations[sta_id].sta.remove_immediate_ba_tid = (u8)tid;
priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
spin_unlock_irqrestore(&priv->sta_lock, flags);
return iwl_send_add_sta(priv, &priv->stations[sta_id].sta,
CMD_ASYNC);
}
EXPORT_SYMBOL(iwl_rx_agg_stop);
/* 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;
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)
priv->last_rx_noise = (total_silence / num_active_rx) - 107;
else
priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
IWL_DEBUG_CALIB("inband silence a %u, b %u, c %u, dBm %d\n",
bcn_silence_a, bcn_silence_b, bcn_silence_c,
priv->last_rx_noise);
}
#define REG_RECALIB_PERIOD (60)
void iwl_rx_statistics(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
int change;
struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
IWL_DEBUG_RX("Statistics notification received (%d vs %d).\n",
(int)sizeof(priv->statistics), pkt->len);
change = ((priv->statistics.general.temperature !=
pkt->u.stats.general.temperature) ||
((priv->statistics.flag &
STATISTICS_REPLY_FLG_FAT_MODE_MSK) !=
(pkt->u.stats.flag & STATISTICS_REPLY_FLG_FAT_MODE_MSK)));
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);
}
iwl_leds_background(priv);
if (priv->cfg->ops->lib->temperature && change)
priv->cfg->ops->lib->temperature(priv);
}
EXPORT_SYMBOL(iwl_rx_statistics);
#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. */
static int iwl_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;
/* Else use just the signal level.
* This formula is a least squares fit of data points collected and
* compared with a reference system that had a percentage (%) display
* for signal quality. */
} else
sig_qual = (100 * (RSSI_RANGE * RSSI_RANGE) - degradation *
(15 * RSSI_RANGE + 62 * degradation)) /
(RSSI_RANGE * RSSI_RANGE);
if (sig_qual > 100)
sig_qual = 100;
else if (sig_qual < 1)
sig_qual = 0;
return sig_qual;
}
#ifdef CONFIG_IWLWIFI_DEBUG
/**
* iwl_dbg_report_frame - dump frame to syslog during debug sessions
*
* You may hack this function to show different aspects of received frames,
* including selective frame dumps.
* group100 parameter selects whether to show 1 out of 100 good frames.
*
* TODO: This was originally written for 3945, need to audit for
* proper operation with 4965.
*/
static void iwl_dbg_report_frame(struct iwl_priv *priv,
struct iwl_rx_packet *pkt,
struct ieee80211_hdr *header, int group100)
{
u32 to_us;
u32 print_summary = 0;
u32 print_dump = 0; /* set to 1 to dump all frames' contents */
u32 hundred = 0;
u32 dataframe = 0;
__le16 fc;
u16 seq_ctl;
u16 channel;
u16 phy_flags;
int rate_sym;
u16 length;
u16 status;
u16 bcn_tmr;
u32 tsf_low;
u64 tsf;
u8 rssi;
u8 agc;
u16 sig_avg;
u16 noise_diff;
struct iwl4965_rx_frame_stats *rx_stats = IWL_RX_STATS(pkt);
struct iwl4965_rx_frame_hdr *rx_hdr = IWL_RX_HDR(pkt);
struct iwl4965_rx_frame_end *rx_end = IWL_RX_END(pkt);
u8 *data = IWL_RX_DATA(pkt);
if (likely(!(priv->debug_level & IWL_DL_RX)))
return;
/* MAC header */
fc = header->frame_control;
seq_ctl = le16_to_cpu(header->seq_ctrl);
/* metadata */
channel = le16_to_cpu(rx_hdr->channel);
phy_flags = le16_to_cpu(rx_hdr->phy_flags);
rate_sym = rx_hdr->rate;
length = le16_to_cpu(rx_hdr->len);
/* end-of-frame status and timestamp */
status = le32_to_cpu(rx_end->status);
bcn_tmr = le32_to_cpu(rx_end->beacon_timestamp);
tsf_low = le64_to_cpu(rx_end->timestamp) & 0x0ffffffff;
tsf = le64_to_cpu(rx_end->timestamp);
/* signal statistics */
rssi = rx_stats->rssi;
agc = rx_stats->agc;
sig_avg = le16_to_cpu(rx_stats->sig_avg);
noise_diff = le16_to_cpu(rx_stats->noise_diff);
to_us = !compare_ether_addr(header->addr1, priv->mac_addr);
/* if data frame is to us and all is good,
* (optionally) print summary for only 1 out of every 100 */
if (to_us && (fc & ~cpu_to_le16(IEEE80211_FCTL_PROTECTED)) ==
cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FTYPE_DATA)) {
dataframe = 1;
if (!group100)
print_summary = 1; /* print each frame */
else if (priv->framecnt_to_us < 100) {
priv->framecnt_to_us++;
print_summary = 0;
} else {
priv->framecnt_to_us = 0;
print_summary = 1;
hundred = 1;
}
} else {
/* print summary for all other frames */
print_summary = 1;
}
if (print_summary) {
char *title;
int rate_idx;
u32 bitrate;
if (hundred)
title = "100Frames";
else if (ieee80211_has_retry(fc))
title = "Retry";
else if (ieee80211_is_assoc_resp(fc))
title = "AscRsp";
else if (ieee80211_is_reassoc_resp(fc))
title = "RasRsp";
else if (ieee80211_is_probe_resp(fc)) {
title = "PrbRsp";
print_dump = 1; /* dump frame contents */
} else if (ieee80211_is_beacon(fc)) {
title = "Beacon";
print_dump = 1; /* dump frame contents */
} else if (ieee80211_is_atim(fc))
title = "ATIM";
else if (ieee80211_is_auth(fc))
title = "Auth";
else if (ieee80211_is_deauth(fc))
title = "DeAuth";
else if (ieee80211_is_disassoc(fc))
title = "DisAssoc";
else
title = "Frame";
rate_idx = iwl_hwrate_to_plcp_idx(rate_sym);
if (unlikely(rate_idx == -1))
bitrate = 0;
else
bitrate = iwl_rates[rate_idx].ieee / 2;
/* print frame summary.
* MAC addresses show just the last byte (for brevity),
* but you can hack it to show more, if you'd like to. */
if (dataframe)
IWL_DEBUG_RX("%s: mhd=0x%04x, dst=0x%02x, "
"len=%u, rssi=%d, chnl=%d, rate=%u, \n",
title, le16_to_cpu(fc), header->addr1[5],
length, rssi, channel, bitrate);
else {
/* src/dst addresses assume managed mode */
IWL_DEBUG_RX("%s: 0x%04x, dst=0x%02x, "
"src=0x%02x, rssi=%u, tim=%lu usec, "
"phy=0x%02x, chnl=%d\n",
title, le16_to_cpu(fc), header->addr1[5],
header->addr3[5], rssi,
tsf_low - priv->scan_start_tsf,
phy_flags, channel);
}
}
if (print_dump)
iwl_print_hex_dump(priv, IWL_DL_RX, data, length);
}
#else
static inline void iwl_dbg_report_frame(struct iwl_priv *priv,
struct iwl_rx_packet *pkt,
struct ieee80211_hdr *header,
int group100)
{
}
#endif
static void iwl_update_rx_stats(struct iwl_priv *priv, u16 fc, u16 len)
{
/* 0 - mgmt, 1 - cnt, 2 - data */
int idx = (fc & IEEE80211_FCTL_FTYPE) >> 2;
priv->rx_stats[idx].cnt++;
priv->rx_stats[idx].bytes += len;
}
/*
* returns non-zero if packet should be dropped
*/
static 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("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("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("hw decrypt successfully!!!\n");
stats->flag |= RX_FLAG_DECRYPTED;
}
break;
default:
break;
}
return 0;
}
static u32 iwl_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in)
{
u32 decrypt_out = 0;
if ((decrypt_in & RX_RES_STATUS_STATION_FOUND) ==
RX_RES_STATUS_STATION_FOUND)
decrypt_out |= (RX_RES_STATUS_STATION_FOUND |
RX_RES_STATUS_NO_STATION_INFO_MISMATCH);
decrypt_out |= (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK);
/* packet was not encrypted */
if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
RX_RES_STATUS_SEC_TYPE_NONE)
return decrypt_out;
/* packet was encrypted with unknown alg */
if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
RX_RES_STATUS_SEC_TYPE_ERR)
return decrypt_out;
/* decryption was not done in HW */
if ((decrypt_in & RX_MPDU_RES_STATUS_DEC_DONE_MSK) !=
RX_MPDU_RES_STATUS_DEC_DONE_MSK)
return decrypt_out;
switch (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) {
case RX_RES_STATUS_SEC_TYPE_CCMP:
/* alg is CCM: check MIC only */
if (!(decrypt_in & RX_MPDU_RES_STATUS_MIC_OK))
/* Bad MIC */
decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
else
decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
break;
case RX_RES_STATUS_SEC_TYPE_TKIP:
if (!(decrypt_in & RX_MPDU_RES_STATUS_TTAK_OK)) {
/* Bad TTAK */
decrypt_out |= RX_RES_STATUS_BAD_KEY_TTAK;
break;
}
/* fall through if TTAK OK */
default:
if (!(decrypt_in & RX_MPDU_RES_STATUS_ICV_OK))
decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
else
decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
break;
};
IWL_DEBUG_RX("decrypt_in:0x%x decrypt_out = 0x%x\n",
decrypt_in, decrypt_out);
return decrypt_out;
}
static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
int include_phy,
struct iwl_rx_mem_buffer *rxb,
struct ieee80211_rx_status *stats)
{
struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
struct iwl_rx_phy_res *rx_start = (include_phy) ?
(struct iwl_rx_phy_res *)&(pkt->u.raw[0]) : NULL;
struct ieee80211_hdr *hdr;
u16 len;
__le32 *rx_end;
unsigned int skblen;
u32 ampdu_status;
u32 ampdu_status_legacy;
if (!include_phy && priv->last_phy_res[0])
rx_start = (struct iwl_rx_phy_res *)&priv->last_phy_res[1];
if (!rx_start) {
IWL_ERROR("MPDU frame without a PHY data\n");
return;
}
if (include_phy) {
hdr = (struct ieee80211_hdr *)((u8 *) &rx_start[1] +
rx_start->cfg_phy_cnt);
len = le16_to_cpu(rx_start->byte_count);
rx_end = (__le32 *)((u8 *) &pkt->u.raw[0] +
sizeof(struct iwl_rx_phy_res) +
rx_start->cfg_phy_cnt + len);
} else {
struct iwl4965_rx_mpdu_res_start *amsdu =
(struct iwl4965_rx_mpdu_res_start *)pkt->u.raw;
hdr = (struct ieee80211_hdr *)(pkt->u.raw +
sizeof(struct iwl4965_rx_mpdu_res_start));
len = le16_to_cpu(amsdu->byte_count);
rx_start->byte_count = amsdu->byte_count;
rx_end = (__le32 *) (((u8 *) hdr) + len);
}
ampdu_status = le32_to_cpu(*rx_end);
skblen = ((u8 *) rx_end - (u8 *) &pkt->u.raw[0]) + sizeof(u32);
if (!include_phy) {
/* New status scheme, need to translate */
ampdu_status_legacy = ampdu_status;
ampdu_status = iwl_translate_rx_status(priv, ampdu_status);
}
/* start from MAC */
skb_reserve(rxb->skb, (void *)hdr - (void *)pkt);
skb_put(rxb->skb, len); /* end where data ends */
/* We only process data packets if the interface is open */
if (unlikely(!priv->is_open)) {
IWL_DEBUG_DROP_LIMIT
("Dropping packet while interface is not open.\n");
return;
}
hdr = (struct ieee80211_hdr *)rxb->skb->data;
/* in case of HW accelerated crypto and bad decryption, drop */
if (!priv->hw_params.sw_crypto &&
iwl_set_decrypted_flag(priv, hdr, ampdu_status, stats))
return;
iwl_update_rx_stats(priv, le16_to_cpu(hdr->frame_control), len);
ieee80211_rx_irqsafe(priv->hw, rxb->skb, stats);
priv->alloc_rxb_skb--;
rxb->skb = NULL;
}
/* Calc max signal level (dBm) among 3 possible receivers */
static inline int iwl_calc_rssi(struct iwl_priv *priv,
struct iwl_rx_phy_res *rx_resp)
{
return priv->cfg->ops->utils->calc_rssi(priv, rx_resp);
}
static void iwl_sta_modify_ps_wake(struct iwl_priv *priv, int sta_id)
{
unsigned long flags;
spin_lock_irqsave(&priv->sta_lock, flags);
priv->stations[sta_id].sta.station_flags &= ~STA_FLG_PWR_SAVE_MSK;
priv->stations[sta_id].sta.station_flags_msk = STA_FLG_PWR_SAVE_MSK;
priv->stations[sta_id].sta.sta.modify_mask = 0;
priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
spin_unlock_irqrestore(&priv->sta_lock, flags);
iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);
}
static void iwl_update_ps_mode(struct iwl_priv *priv, u16 ps_bit, u8 *addr)
{
/* FIXME: need locking over ps_status ??? */
u8 sta_id = iwl_find_station(priv, addr);
if (sta_id != IWL_INVALID_STATION) {
u8 sta_awake = priv->stations[sta_id].
ps_status == STA_PS_STATUS_WAKE;
if (sta_awake && ps_bit)
priv->stations[sta_id].ps_status = STA_PS_STATUS_SLEEP;
else if (!sta_awake && !ps_bit) {
iwl_sta_modify_ps_wake(priv, sta_id);
priv->stations[sta_id].ps_status = STA_PS_STATUS_WAKE;
}
}
}
/* This is necessary only for a number of statistics, see the caller. */
static int iwl_is_network_packet(struct iwl_priv *priv,
struct ieee80211_hdr *header)
{
/* Filter incoming packets to determine if they are targeted toward
* this network, discarding packets coming from ourselves */
switch (priv->iw_mode) {
case NL80211_IFTYPE_ADHOC: /* Header: Dest. | Source | BSSID */
/* packets to our IBSS update information */
return !compare_ether_addr(header->addr3, priv->bssid);
case NL80211_IFTYPE_STATION: /* Header: Dest. | AP{BSSID} | Source */
/* packets to our IBSS update information */
return !compare_ether_addr(header->addr2, priv->bssid);
default:
return 1;
}
}
/* Called for REPLY_RX (legacy ABG frames), or
* REPLY_RX_MPDU_CMD (HT high-throughput N frames). */
void iwl_rx_reply_rx(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct ieee80211_hdr *header;
struct ieee80211_rx_status rx_status;
struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
/* Use phy data (Rx signal strength, etc.) contained within
* this rx packet for legacy frames,
* or phy data cached from REPLY_RX_PHY_CMD for HT frames. */
int include_phy = (pkt->hdr.cmd == REPLY_RX);
struct iwl_rx_phy_res *rx_start = (include_phy) ?
(struct iwl_rx_phy_res *)&(pkt->u.raw[0]) :
(struct iwl_rx_phy_res *)&priv->last_phy_res[1];
__le32 *rx_end;
unsigned int len = 0;
u16 fc;
u8 network_packet;
rx_status.mactime = le64_to_cpu(rx_start->timestamp);
rx_status.freq =
ieee80211_channel_to_frequency(le16_to_cpu(rx_start->channel));
rx_status.band = (rx_start->phy_flags & RX_RES_PHY_FLAGS_BAND_24_MSK) ?
IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ;
rx_status.rate_idx =
iwl_hwrate_to_plcp_idx(le32_to_cpu(rx_start->rate_n_flags));
if (rx_status.band == IEEE80211_BAND_5GHZ)
rx_status.rate_idx -= IWL_FIRST_OFDM_RATE;
rx_status.flag = 0;
/* TSF isn't reliable. In order to allow smooth user experience,
* this W/A doesn't propagate it to the mac80211 */
/*rx_status.flag |= RX_FLAG_TSFT;*/
if ((unlikely(rx_start->cfg_phy_cnt > 20))) {
IWL_DEBUG_DROP("dsp size out of range [0,20]: %d/n",
rx_start->cfg_phy_cnt);
return;
}
if (!include_phy) {
if (priv->last_phy_res[0])
rx_start = (struct iwl_rx_phy_res *)
&priv->last_phy_res[1];
else
rx_start = NULL;
}
if (!rx_start) {
IWL_ERROR("MPDU frame without a PHY data\n");
return;
}
if (include_phy) {
header = (struct ieee80211_hdr *)((u8 *) &rx_start[1]
+ rx_start->cfg_phy_cnt);
len = le16_to_cpu(rx_start->byte_count);
rx_end = (__le32 *)(pkt->u.raw + rx_start->cfg_phy_cnt +
sizeof(struct iwl_rx_phy_res) + len);
} else {
struct iwl4965_rx_mpdu_res_start *amsdu =
(struct iwl4965_rx_mpdu_res_start *)pkt->u.raw;
header = (void *)(pkt->u.raw +
sizeof(struct iwl4965_rx_mpdu_res_start));
len = le16_to_cpu(amsdu->byte_count);
rx_end = (__le32 *) (pkt->u.raw +
sizeof(struct iwl4965_rx_mpdu_res_start) + len);
}
if (!(*rx_end & RX_RES_STATUS_NO_CRC32_ERROR) ||
!(*rx_end & RX_RES_STATUS_NO_RXE_OVERFLOW)) {
IWL_DEBUG_RX("Bad CRC or FIFO: 0x%08X.\n",
le32_to_cpu(*rx_end));
return;
}
priv->ucode_beacon_time = le32_to_cpu(rx_start->beacon_time_stamp);
/* Find max signal strength (dBm) among 3 antenna/receiver chains */
rx_status.signal = iwl_calc_rssi(priv, rx_start);
/* Meaningful noise values are available only from beacon statistics,
* which are gathered only when associated, and indicate noise
* only for the associated network channel ...
* Ignore these noise values while scanning (other channels) */
if (iwl_is_associated(priv) &&
!test_bit(STATUS_SCANNING, &priv->status)) {
rx_status.noise = priv->last_rx_noise;
rx_status.qual = iwl_calc_sig_qual(rx_status.signal,
rx_status.noise);
} else {
rx_status.noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
rx_status.qual = iwl_calc_sig_qual(rx_status.signal, 0);
}
/* Reset beacon noise level if not associated. */
if (!iwl_is_associated(priv))
priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
/* Set "1" to report good data frames in groups of 100 */
/* FIXME: need to optimze the call: */
iwl_dbg_report_frame(priv, pkt, header, 1);
IWL_DEBUG_STATS_LIMIT("Rssi %d, noise %d, qual %d, TSF %llu\n",
rx_status.signal, rx_status.noise, rx_status.signal,
(unsigned long long)rx_status.mactime);
/*
* "antenna number"
*
* It seems that the antenna field in the phy flags value
* is actually a bitfield. This is undefined by radiotap,
* it wants an actual antenna number but I always get "7"
* for most legacy frames I receive indicating that the
* same frame was received on all three RX chains.
*
* I think this field should be removed in favour of a
* new 802.11n radiotap field "RX chains" that is defined
* as a bitmask.
*/
rx_status.antenna = le16_to_cpu(rx_start->phy_flags &
RX_RES_PHY_FLAGS_ANTENNA_MSK) >> 4;
/* set the preamble flag if appropriate */
if (rx_start->phy_flags & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
rx_status.flag |= RX_FLAG_SHORTPRE;
/* Take shortcut when only in monitor mode */
if (priv->iw_mode == NL80211_IFTYPE_MONITOR) {
iwl_pass_packet_to_mac80211(priv, include_phy,
rxb, &rx_status);
return;
}
network_packet = iwl_is_network_packet(priv, header);
if (network_packet) {
priv->last_rx_rssi = rx_status.signal;
priv->last_beacon_time = priv->ucode_beacon_time;
priv->last_tsf = le64_to_cpu(rx_start->timestamp);
}
fc = le16_to_cpu(header->frame_control);
switch (fc & IEEE80211_FCTL_FTYPE) {
case IEEE80211_FTYPE_MGMT:
case IEEE80211_FTYPE_DATA:
if (priv->iw_mode == NL80211_IFTYPE_AP)
iwl_update_ps_mode(priv, fc & IEEE80211_FCTL_PM,
header->addr2);
/* fall through */
default:
iwl_pass_packet_to_mac80211(priv, include_phy, rxb,
&rx_status);
break;
}
}
EXPORT_SYMBOL(iwl_rx_reply_rx);
/* Cache phy data (Rx signal strength, etc) for HT frame (REPLY_RX_PHY_CMD).
* This will be used later in iwl_rx_reply_rx() for REPLY_RX_MPDU_CMD. */
void iwl_rx_reply_rx_phy(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
priv->last_phy_res[0] = 1;
memcpy(&priv->last_phy_res[1], &(pkt->u.raw[0]),
sizeof(struct iwl_rx_phy_res));
}
EXPORT_SYMBOL(iwl_rx_reply_rx_phy);
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