/****************************************************************************** * * 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 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 * *****************************************************************************/ #include #include #include #include #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 il_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: * * il_rx_queue_alloc() Allocates rx_free * il_rx_replenish() Replenishes rx_free list from rx_used, and calls * il_rx_queue_restock * il_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 il_rx_replenish * * -- enable interrupts -- * ISR - il_rx() Detach il_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 il_rx_queue_restock to refill any empty * slots. * ... * */ /** * il_rx_queue_space - Return number of free slots available in queue. */ int il_rx_queue_space(const struct il_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(il_rx_queue_space); /** * il_rx_queue_update_write_ptr - Update the write pointer for the RX queue */ void il_rx_queue_update_write_ptr(struct il_priv *il, struct il_rx_queue *q) { unsigned long flags; u32 rx_wrt_ptr_reg = il->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, &il->status)) { reg = _il_rd(il, CSR_UCODE_DRV_GP1); if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) { D_INFO( "Rx queue requesting wakeup," " GP1 = 0x%x\n", reg); il_set_bit(il, CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ); goto exit_unlock; } q->write_actual = (q->write & ~0x7); il_wr(il, 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); il_wr(il, rx_wrt_ptr_reg, q->write_actual); } q->need_update = 0; exit_unlock: spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(il_rx_queue_update_write_ptr); int il_rx_queue_alloc(struct il_priv *il) { struct il_rx_queue *rxq = &il->rxq; struct device *dev = &il->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 il_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(&il->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd, rxq->bd_dma); err_bd: return -ENOMEM; } EXPORT_SYMBOL(il_rx_queue_alloc); void il_rx_spectrum_measure_notif(struct il_priv *il, struct il_rx_mem_buffer *rxb) { struct il_rx_packet *pkt = rxb_addr(rxb); struct il_spectrum_notification *report = &(pkt->u.spectrum_notif); if (!report->state) { D_11H( "Spectrum Measure Notification: Start\n"); return; } memcpy(&il->measure_report, report, sizeof(*report)); il->measurement_status |= MEASUREMENT_READY; } EXPORT_SYMBOL(il_rx_spectrum_measure_notif); /* * returns non-zero if packet should be dropped */ int il_set_decrypted_flag(struct il_priv *il, 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 (il->contexts[IL_RXON_CTX_BSS].active.filter_flags & RXON_FILTER_DIS_DECRYPT_MSK) return 0; if (!(fc & IEEE80211_FCTL_PROTECTED)) return 0; D_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 */ D_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) { D_RX("hw decrypt successfully!!!\n"); stats->flag |= RX_FLAG_DECRYPTED; } break; default: break; } return 0; } EXPORT_SYMBOL(il_set_decrypted_flag);