diff options
Diffstat (limited to 'drivers/net/wireless/iwlegacy/iwl-rx.c')
| -rw-r--r-- | drivers/net/wireless/iwlegacy/iwl-rx.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/net/wireless/iwlegacy/iwl-rx.c b/drivers/net/wireless/iwlegacy/iwl-rx.c new file mode 100644 index 000000000000..654cf233a384 --- /dev/null +++ b/drivers/net/wireless/iwlegacy/iwl-rx.c @@ -0,0 +1,302 @@ +/****************************************************************************** + * + * Copyright(c) 2003 - 2011 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 <linux/slab.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-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_legacy_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_legacy_rx_queue_space - Return number of free slots available in queue. + */ +int iwl_legacy_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_legacy_rx_queue_space); + +/** + * iwl_legacy_rx_queue_update_write_ptr - Update the write pointer for the RX queue + */ +void +iwl_legacy_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_legacy_set_bit(priv, CSR_GP_CNTRL, + CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ); + goto exit_unlock; + } + + q->write_actual = (q->write & ~0x7); + iwl_legacy_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_legacy_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_legacy_rx_queue_update_write_ptr); + +int iwl_legacy_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->bd_dma, + 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->bd_dma); +err_bd: + return -ENOMEM; +} +EXPORT_SYMBOL(iwl_legacy_rx_queue_alloc); + + +void iwl_legacy_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_legacy_rx_spectrum_measure_notif); + +void iwl_legacy_recover_from_statistics(struct iwl_priv *priv, + struct iwl_rx_packet *pkt) +{ + if (test_bit(STATUS_EXIT_PENDING, &priv->status)) + return; + if (iwl_legacy_is_any_associated(priv)) { + 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_legacy_force_reset(priv, + IWL_RF_RESET, false); + } + } + } +} +EXPORT_SYMBOL(iwl_legacy_recover_from_statistics); + +/* + * returns non-zero if packet should be dropped + */ +int iwl_legacy_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); + + /* + * All contexts have the same setting here due to it being + * a module parameter, so OK to check any context. + */ + if (priv->contexts[IWL_RXON_CTX_BSS].active.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_legacy_set_decrypted_flag); |