/****************************************************************************** * * 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 "iwl-dev.h" #include "iwl-agn.h" #include "iwl-core.h" #include "iwl-io.h" #include "iwl-helpers.h" #include "iwl-trans-int-pcie.h" /****************************************************************************** * * RX path 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. */ static 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; } /** * 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 reg; spin_lock_irqsave(&q->lock, flags); if (q->need_update == 0) goto exit_unlock; if (priv->cfg->base_params->shadow_reg_enable) { /* shadow register enabled */ /* Device expects a multiple of 8 */ q->write_actual = (q->write & ~0x7); iwl_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write_actual); } else { /* 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, FH_RSCSR_CHNL0_WPTR, 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, FH_RSCSR_CHNL0_WPTR, q->write_actual); } } q->need_update = 0; exit_unlock: spin_unlock_irqrestore(&q->lock, flags); } /** * iwlagn_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr */ static inline __le32 iwlagn_dma_addr2rbd_ptr(struct iwl_priv *priv, dma_addr_t dma_addr) { return cpu_to_le32((u32)(dma_addr >> 8)); } /** * iwlagn_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. */ static void iwlagn_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; spin_lock_irqsave(&rxq->lock, flags); while ((iwl_rx_queue_space(rxq) > 0) && (rxq->free_count)) { /* The overwritten rxb must be a used one */ rxb = rxq->queue[rxq->write]; BUG_ON(rxb && rxb->page); /* 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] = iwlagn_dma_addr2rbd_ptr(priv, rxb->page_dma); 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 (rxq->write_actual != (rxq->write & ~0x7)) { spin_lock_irqsave(&rxq->lock, flags); rxq->need_update = 1; spin_unlock_irqrestore(&rxq->lock, flags); iwl_rx_queue_update_write_ptr(priv, rxq); } } /** * iwlagn_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) */ static void iwlagn_rx_allocate(struct iwl_priv *priv, gfp_t priority) { struct iwl_rx_queue *rxq = &priv->rxq; struct list_head *element; struct iwl_rx_mem_buffer *rxb; struct page *page; unsigned long flags; gfp_t gfp_mask = priority; while (1) { spin_lock_irqsave(&rxq->lock, flags); if (list_empty(&rxq->rx_used)) { spin_unlock_irqrestore(&rxq->lock, flags); return; } spin_unlock_irqrestore(&rxq->lock, flags); if (rxq->free_count > RX_LOW_WATERMARK) gfp_mask |= __GFP_NOWARN; if (priv->hw_params.rx_page_order > 0) gfp_mask |= __GFP_COMP; /* Alloc a new receive buffer */ page = alloc_pages(gfp_mask, priv->hw_params.rx_page_order); if (!page) { if (net_ratelimit()) IWL_DEBUG_INFO(priv, "alloc_pages failed, " "order: %d\n", priv->hw_params.rx_page_order); if ((rxq->free_count <= RX_LOW_WATERMARK) && net_ratelimit()) IWL_CRIT(priv, "Failed to alloc_pages with %s." "Only %u free buffers remaining.\n", priority == GFP_ATOMIC ? "GFP_ATOMIC" : "GFP_KERNEL", rxq->free_count); /* We don't reschedule replenish work here -- we will * call the restock method and if it still needs * more buffers it will schedule replenish */ return; } spin_lock_irqsave(&rxq->lock, flags); if (list_empty(&rxq->rx_used)) { spin_unlock_irqrestore(&rxq->lock, flags); __free_pages(page, priv->hw_params.rx_page_order); return; } element = rxq->rx_used.next; rxb = list_entry(element, struct iwl_rx_mem_buffer, list); list_del(element); spin_unlock_irqrestore(&rxq->lock, flags); BUG_ON(rxb->page); rxb->page = page; /* Get physical address of the RB */ rxb->page_dma = dma_map_page(priv->bus.dev, page, 0, PAGE_SIZE << priv->hw_params.rx_page_order, DMA_FROM_DEVICE); /* dma address must be no more than 36 bits */ BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36)); /* and also 256 byte aligned! */ BUG_ON(rxb->page_dma & DMA_BIT_MASK(8)); spin_lock_irqsave(&rxq->lock, flags); list_add_tail(&rxb->list, &rxq->rx_free); rxq->free_count++; spin_unlock_irqrestore(&rxq->lock, flags); } } void iwlagn_rx_replenish(struct iwl_priv *priv) { unsigned long flags; iwlagn_rx_allocate(priv, GFP_KERNEL); spin_lock_irqsave(&priv->lock, flags); iwlagn_rx_queue_restock(priv); spin_unlock_irqrestore(&priv->lock, flags); } static void iwlagn_rx_replenish_now(struct iwl_priv *priv) { iwlagn_rx_allocate(priv, GFP_ATOMIC); iwlagn_rx_queue_restock(priv); } void iwl_bg_rx_replenish(struct work_struct *data) { struct iwl_priv *priv = container_of(data, struct iwl_priv, rx_replenish); if (test_bit(STATUS_EXIT_PENDING, &priv->status)) return; mutex_lock(&priv->mutex); iwlagn_rx_replenish(priv); mutex_unlock(&priv->mutex); } /** * iwl_rx_handle - Main entry function for receiving responses from uCode * * Uses the priv->rx_handlers callback function array to invoke * the appropriate handlers, including command responses, * frame-received notifications, and other notifications. */ static void iwl_rx_handle(struct iwl_priv *priv) { struct iwl_rx_mem_buffer *rxb; struct iwl_rx_packet *pkt; struct iwl_rx_queue *rxq = &priv->rxq; u32 r, i; int reclaim; unsigned long flags; u8 fill_rx = 0; u32 count = 8; int total_empty; /* uCode's read index (stored in shared DRAM) indicates the last Rx * buffer that the driver may process (last buffer filled by ucode). */ r = le16_to_cpu(rxq->rb_stts->closed_rb_num) & 0x0FFF; i = rxq->read; /* Rx interrupt, but nothing sent from uCode */ if (i == r) IWL_DEBUG_RX(priv, "r = %d, i = %d\n", r, i); /* calculate total frames need to be restock after handling RX */ total_empty = r - rxq->write_actual; if (total_empty < 0) total_empty += RX_QUEUE_SIZE; if (total_empty > (RX_QUEUE_SIZE / 2)) fill_rx = 1; while (i != r) { int len; rxb = rxq->queue[i]; /* If an RXB doesn't have a Rx queue slot associated with it, * then a bug has been introduced in the queue refilling * routines -- catch it here */ if (WARN_ON(rxb == NULL)) { i = (i + 1) & RX_QUEUE_MASK; continue; } rxq->queue[i] = NULL; dma_unmap_page(priv->bus.dev, rxb->page_dma, PAGE_SIZE << priv->hw_params.rx_page_order, DMA_FROM_DEVICE); pkt = rxb_addr(rxb); IWL_DEBUG_RX(priv, "r = %d, i = %d, %s, 0x%02x\n", r, i, get_cmd_string(pkt->hdr.cmd), pkt->hdr.cmd); len = le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK; len += sizeof(u32); /* account for status word */ trace_iwlwifi_dev_rx(priv, pkt, len); /* Reclaim a command buffer only if this packet is a response * to a (driver-originated) command. * If the packet (e.g. Rx frame) originated from uCode, * there is no command buffer to reclaim. * Ucode should set SEQ_RX_FRAME bit if ucode-originated, * but apparently a few don't get set; catch them here. */ reclaim = !(pkt->hdr.sequence & SEQ_RX_FRAME) && (pkt->hdr.cmd != REPLY_RX_PHY_CMD) && (pkt->hdr.cmd != REPLY_RX) && (pkt->hdr.cmd != REPLY_RX_MPDU_CMD) && (pkt->hdr.cmd != REPLY_COMPRESSED_BA) && (pkt->hdr.cmd != STATISTICS_NOTIFICATION) && (pkt->hdr.cmd != REPLY_TX); iwl_rx_dispatch(priv, rxb); /* * XXX: After here, we should always check rxb->page * against NULL before touching it or its virtual * memory (pkt). Because some rx_handler might have * already taken or freed the pages. */ if (reclaim) { /* Invoke any callbacks, transfer the buffer to caller, * and fire off the (possibly) blocking * trans_send_cmd() * as we reclaim the driver command queue */ if (rxb->page) iwl_tx_cmd_complete(priv, rxb); else IWL_WARN(priv, "Claim null rxb?\n"); } /* Reuse the page if possible. For notification packets and * SKBs that fail to Rx correctly, add them back into the * rx_free list for reuse later. */ spin_lock_irqsave(&rxq->lock, flags); if (rxb->page != NULL) { rxb->page_dma = dma_map_page(priv->bus.dev, rxb->page, 0, PAGE_SIZE << priv->hw_params.rx_page_order, DMA_FROM_DEVICE); list_add_tail(&rxb->list, &rxq->rx_free); rxq->free_count++; } else list_add_tail(&rxb->list, &rxq->rx_used); spin_unlock_irqrestore(&rxq->lock, flags); i = (i + 1) & RX_QUEUE_MASK; /* If there are a lot of unused frames, * restock the Rx queue so ucode wont assert. */ if (fill_rx) { count++; if (count >= 8) { rxq->read = i; iwlagn_rx_replenish_now(priv); count = 0; } } } /* Backtrack one entry */ rxq->read = i; if (fill_rx) iwlagn_rx_replenish_now(priv); else iwlagn_rx_queue_restock(priv); } /* tasklet for iwlagn interrupt */ void iwl_irq_tasklet(struct iwl_priv *priv) { u32 inta = 0; u32 handled = 0; unsigned long flags; u32 i; #ifdef CONFIG_IWLWIFI_DEBUG u32 inta_mask; #endif spin_lock_irqsave(&priv->lock, flags); /* Ack/clear/reset pending uCode interrupts. * Note: Some bits in CSR_INT are "OR" of bits in CSR_FH_INT_STATUS, */ /* There is a hardware bug in the interrupt mask function that some * interrupts (i.e. CSR_INT_BIT_SCD) can still be generated even if * they are disabled in the CSR_INT_MASK register. Furthermore the * ICT interrupt handling mechanism has another bug that might cause * these unmasked interrupts fail to be detected. We workaround the * hardware bugs here by ACKing all the possible interrupts so that * interrupt coalescing can still be achieved. */ iwl_write32(priv, CSR_INT, priv->_agn.inta | ~priv->inta_mask); inta = priv->_agn.inta; #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_get_debug_level(priv) & IWL_DL_ISR) { /* just for debug */ inta_mask = iwl_read32(priv, CSR_INT_MASK); IWL_DEBUG_ISR(priv, "inta 0x%08x, enabled 0x%08x\n ", inta, inta_mask); } #endif spin_unlock_irqrestore(&priv->lock, flags); /* saved interrupt in inta variable now we can reset priv->_agn.inta */ priv->_agn.inta = 0; /* Now service all interrupt bits discovered above. */ if (inta & CSR_INT_BIT_HW_ERR) { IWL_ERR(priv, "Hardware error detected. Restarting.\n"); /* Tell the device to stop sending interrupts */ iwl_disable_interrupts(priv); priv->isr_stats.hw++; iwl_irq_handle_error(priv); handled |= CSR_INT_BIT_HW_ERR; return; } #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_get_debug_level(priv) & (IWL_DL_ISR)) { /* NIC fires this, but we don't use it, redundant with WAKEUP */ if (inta & CSR_INT_BIT_SCD) { IWL_DEBUG_ISR(priv, "Scheduler finished to transmit " "the frame/frames.\n"); priv->isr_stats.sch++; } /* Alive notification via Rx interrupt will do the real work */ if (inta & CSR_INT_BIT_ALIVE) { IWL_DEBUG_ISR(priv, "Alive interrupt\n"); priv->isr_stats.alive++; } } #endif /* Safely ignore these bits for debug checks below */ inta &= ~(CSR_INT_BIT_SCD | CSR_INT_BIT_ALIVE); /* HW RF KILL switch toggled */ if (inta & CSR_INT_BIT_RF_KILL) { int hw_rf_kill = 0; if (!(iwl_read32(priv, CSR_GP_CNTRL) & CSR_GP_CNTRL_REG_FLAG_HW_RF_KILL_SW)) hw_rf_kill = 1; IWL_WARN(priv, "RF_KILL bit toggled to %s.\n", hw_rf_kill ? "disable radio" : "enable radio"); priv->isr_stats.rfkill++; /* driver only loads ucode once setting the interface up. * the driver allows loading the ucode even if the radio * is killed. Hence update the killswitch state here. The * rfkill handler will care about restarting if needed. */ if (!test_bit(STATUS_ALIVE, &priv->status)) { if (hw_rf_kill) set_bit(STATUS_RF_KILL_HW, &priv->status); else clear_bit(STATUS_RF_KILL_HW, &priv->status); wiphy_rfkill_set_hw_state(priv->hw->wiphy, hw_rf_kill); } handled |= CSR_INT_BIT_RF_KILL; } /* Chip got too hot and stopped itself */ if (inta & CSR_INT_BIT_CT_KILL) { IWL_ERR(priv, "Microcode CT kill error detected.\n"); priv->isr_stats.ctkill++; handled |= CSR_INT_BIT_CT_KILL; } /* Error detected by uCode */ if (inta & CSR_INT_BIT_SW_ERR) { IWL_ERR(priv, "Microcode SW error detected. " " Restarting 0x%X.\n", inta); priv->isr_stats.sw++; iwl_irq_handle_error(priv); handled |= CSR_INT_BIT_SW_ERR; } /* uCode wakes up after power-down sleep */ if (inta & CSR_INT_BIT_WAKEUP) { IWL_DEBUG_ISR(priv, "Wakeup interrupt\n"); iwl_rx_queue_update_write_ptr(priv, &priv->rxq); for (i = 0; i < priv->hw_params.max_txq_num; i++) iwl_txq_update_write_ptr(priv, &priv->txq[i]); priv->isr_stats.wakeup++; handled |= CSR_INT_BIT_WAKEUP; } /* All uCode command responses, including Tx command responses, * Rx "responses" (frame-received notification), and other * notifications from uCode come through here*/ if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX | CSR_INT_BIT_RX_PERIODIC)) { IWL_DEBUG_ISR(priv, "Rx interrupt\n"); if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX)) { handled |= (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX); iwl_write32(priv, CSR_FH_INT_STATUS, CSR_FH_INT_RX_MASK); } if (inta & CSR_INT_BIT_RX_PERIODIC) { handled |= CSR_INT_BIT_RX_PERIODIC; iwl_write32(priv, CSR_INT, CSR_INT_BIT_RX_PERIODIC); } /* Sending RX interrupt require many steps to be done in the * the device: * 1- write interrupt to current index in ICT table. * 2- dma RX frame. * 3- update RX shared data to indicate last write index. * 4- send interrupt. * This could lead to RX race, driver could receive RX interrupt * but the shared data changes does not reflect this; * periodic interrupt will detect any dangling Rx activity. */ /* Disable periodic interrupt; we use it as just a one-shot. */ iwl_write8(priv, CSR_INT_PERIODIC_REG, CSR_INT_PERIODIC_DIS); iwl_rx_handle(priv); /* * Enable periodic interrupt in 8 msec only if we received * real RX interrupt (instead of just periodic int), to catch * any dangling Rx interrupt. If it was just the periodic * interrupt, there was no dangling Rx activity, and no need * to extend the periodic interrupt; one-shot is enough. */ if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX)) iwl_write8(priv, CSR_INT_PERIODIC_REG, CSR_INT_PERIODIC_ENA); priv->isr_stats.rx++; } /* This "Tx" DMA channel is used only for loading uCode */ if (inta & CSR_INT_BIT_FH_TX) { iwl_write32(priv, CSR_FH_INT_STATUS, CSR_FH_INT_TX_MASK); IWL_DEBUG_ISR(priv, "uCode load interrupt\n"); priv->isr_stats.tx++; handled |= CSR_INT_BIT_FH_TX; /* Wake up uCode load routine, now that load is complete */ priv->ucode_write_complete = 1; wake_up_interruptible(&priv->wait_command_queue); } if (inta & ~handled) { IWL_ERR(priv, "Unhandled INTA bits 0x%08x\n", inta & ~handled); priv->isr_stats.unhandled++; } if (inta & ~(priv->inta_mask)) { IWL_WARN(priv, "Disabled INTA bits 0x%08x were pending\n", inta & ~priv->inta_mask); } /* Re-enable all interrupts */ /* only Re-enable if disabled by irq */ if (test_bit(STATUS_INT_ENABLED, &priv->status)) iwl_enable_interrupts(priv); /* Re-enable RF_KILL if it occurred */ else if (handled & CSR_INT_BIT_RF_KILL) iwl_enable_rfkill_int(priv); }