示例#1
0
static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
				struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	struct iwl_txq *txq = &trans_pcie->txq[trans_pcie->cmd_queue];
	unsigned long flags;
	bool page_stolen = false;
	int max_len = PAGE_SIZE << trans_pcie->rx_page_order;
	u32 offset = 0;

	if (WARN_ON(!rxb))
		return;

	dma_unmap_page(trans->dev, rxb->page_dma, max_len, DMA_FROM_DEVICE);

	while (offset + sizeof(u32) + sizeof(struct iwl_cmd_header) < max_len) {
		struct iwl_rx_packet *pkt;
		struct iwl_device_cmd *cmd;
		u16 sequence;
		bool reclaim;
		int index, cmd_index, err, len;
		struct iwl_rx_cmd_buffer rxcb = {
			._offset = offset,
			._rx_page_order = trans_pcie->rx_page_order,
			._page = rxb->page,
			._page_stolen = false,
			.truesize = max_len,
		};

		pkt = rxb_addr(&rxcb);

		if (pkt->len_n_flags == cpu_to_le32(FH_RSCSR_FRAME_INVALID))
			break;

		IWL_DEBUG_RX(trans, "cmd at offset %d: %s (0x%.2x)\n",
			rxcb._offset, get_cmd_string(trans_pcie, 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(trans->dev, trans, pkt, len);
		trace_iwlwifi_dev_rx_data(trans->dev, trans, 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);
		if (reclaim) {
			int i;

			for (i = 0; i < trans_pcie->n_no_reclaim_cmds; i++) {
				if (trans_pcie->no_reclaim_cmds[i] ==
							pkt->hdr.cmd) {
					reclaim = false;
					break;
				}
			}
		}

		sequence = le16_to_cpu(pkt->hdr.sequence);
		index = SEQ_TO_INDEX(sequence);
		cmd_index = get_cmd_index(&txq->q, index);

		if (reclaim)
			cmd = txq->entries[cmd_index].cmd;
		else
			cmd = NULL;

		err = iwl_op_mode_rx(trans->op_mode, &rxcb, cmd);

		if (reclaim) {
			kfree(txq->entries[cmd_index].free_buf);
			txq->entries[cmd_index].free_buf = NULL;
		}

		/*
		 * After here, we should always check rxcb._page_stolen,
		 * if it is true then one of the handlers took the page.
		 */

		if (reclaim) {
			/* Invoke any callbacks, transfer the buffer to caller,
			 * and fire off the (possibly) blocking
			 * iwl_trans_send_cmd()
			 * as we reclaim the driver command queue */
			if (!rxcb._page_stolen)
				iwl_pcie_hcmd_complete(trans, &rxcb, err);
			else
				IWL_WARN(trans, "Claim null rxb?\n");
		}

		page_stolen |= rxcb._page_stolen;
		offset += ALIGN(len, FH_RSCSR_FRAME_ALIGN);
	}

	/* page was stolen from us -- free our reference */
	if (page_stolen) {
		__free_pages(rxb->page, trans_pcie->rx_page_order);
		rxb->page = NULL;
	}

	/* 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(trans->dev, rxb->page, 0,
				     PAGE_SIZE << trans_pcie->rx_page_order,
				     DMA_FROM_DEVICE);
		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
			/*
			 * free the page(s) as well to not break
			 * the invariant that the items on the used
			 * list have no page(s)
			 */
			__free_pages(rxb->page, trans_pcie->rx_page_order);
			rxb->page = NULL;
			list_add_tail(&rxb->list, &rxq->rx_used);
		} else {
			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);
}

/*
 * iwl_pcie_rx_handle - Main entry function for receiving responses from fw
 */
static void iwl_pcie_rx_handle(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	u32 r, i;
	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(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
	i = rxq->read;

	/* Rx interrupt, but nothing sent from uCode */
	if (i == r)
		IWL_DEBUG_RX(trans, "HW = SW = %d\n", r);

	/* 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) {
		struct iwl_rx_mem_buffer *rxb;

		rxb = rxq->queue[i];
		rxq->queue[i] = NULL;

		IWL_DEBUG_RX(trans, "rxbuf: HW = %d, SW = %d (%p)\n",
			     r, i, rxb);
		iwl_pcie_rx_handle_rb(trans, rxb);

		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;
				iwl_pcie_rx_replenish_now(trans);
				count = 0;
			}
		}
	}

	/* Backtrack one entry */
	rxq->read = i;
	if (fill_rx)
		iwl_pcie_rx_replenish_now(trans);
	else
		iwl_pcie_rxq_restock(trans);
}

/*
 * iwl_pcie_irq_handle_error - called for HW or SW error interrupt from card
 */
static void iwl_pcie_irq_handle_error(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	/* W/A for WiFi/WiMAX coex and WiMAX own the RF */
	if (trans->cfg->internal_wimax_coex &&
	    (!(iwl_read_prph(trans, APMG_CLK_CTRL_REG) &
			     APMS_CLK_VAL_MRB_FUNC_MODE) ||
	     (iwl_read_prph(trans, APMG_PS_CTRL_REG) &
			    APMG_PS_CTRL_VAL_RESET_REQ))) {
		clear_bit(STATUS_HCMD_ACTIVE, &trans_pcie->status);
		iwl_op_mode_wimax_active(trans->op_mode);
		wake_up(&trans_pcie->wait_command_queue);
		return;
	}

	iwl_pcie_dump_csr(trans);
	iwl_pcie_dump_fh(trans, NULL);

	set_bit(STATUS_FW_ERROR, &trans_pcie->status);
	clear_bit(STATUS_HCMD_ACTIVE, &trans_pcie->status);
	wake_up(&trans_pcie->wait_command_queue);

	local_bh_disable();
	iwl_op_mode_nic_error(trans->op_mode);
	local_bh_enable();
}

irqreturn_t iwl_pcie_irq_handler(int irq, void *dev_id)
{
	struct iwl_trans *trans = dev_id;
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct isr_statistics *isr_stats = &trans_pcie->isr_stats;
	u32 inta = 0;
	u32 handled = 0;
	unsigned long flags;
	u32 i;
#ifdef CPTCFG_IWLWIFI_DEBUG
	u32 inta_mask;
#endif

	lock_map_acquire(&trans->sync_cmd_lockdep_map);

	spin_lock_irqsave(&trans_pcie->irq_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(trans, CSR_INT,
		    trans_pcie->inta | ~trans_pcie->inta_mask);

	inta = trans_pcie->inta;

#ifdef CPTCFG_IWLWIFI_DEBUG
	if (iwl_have_debug_level(IWL_DL_ISR)) {
		/* just for debug */
		inta_mask = iwl_read32(trans, CSR_INT_MASK);
		IWL_DEBUG_ISR(trans, "inta 0x%08x, enabled 0x%08x\n",
			      inta, inta_mask);
	}
#endif

	/* saved interrupt in inta variable now we can reset trans_pcie->inta */
	trans_pcie->inta = 0;

	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);

	/* Now service all interrupt bits discovered above. */
	if (inta & CSR_INT_BIT_HW_ERR) {
		IWL_ERR(trans, "Hardware error detected.  Restarting.\n");

		/* Tell the device to stop sending interrupts */
		iwl_disable_interrupts(trans);

		isr_stats->hw++;
		iwl_pcie_irq_handle_error(trans);

		handled |= CSR_INT_BIT_HW_ERR;

		goto out;
	}

#ifdef CPTCFG_IWLWIFI_DEBUG
	if (iwl_have_debug_level(IWL_DL_ISR)) {
		/* NIC fires this, but we don't use it, redundant with WAKEUP */
		if (inta & CSR_INT_BIT_SCD) {
			IWL_DEBUG_ISR(trans, "Scheduler finished to transmit "
				      "the frame/frames.\n");
			isr_stats->sch++;
		}

		/* Alive notification via Rx interrupt will do the real work */
		if (inta & CSR_INT_BIT_ALIVE) {
			IWL_DEBUG_ISR(trans, "Alive interrupt\n");
			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) {
		bool hw_rfkill;

		hw_rfkill = iwl_is_rfkill_set(trans);
		IWL_WARN(trans, "RF_KILL bit toggled to %s.\n",
			 hw_rfkill ? "disable radio" : "enable radio");

		isr_stats->rfkill++;

		iwl_op_mode_hw_rf_kill(trans->op_mode, hw_rfkill);
		if (hw_rfkill) {
			set_bit(STATUS_RFKILL, &trans_pcie->status);
			if (test_and_clear_bit(STATUS_HCMD_ACTIVE,
					       &trans_pcie->status))
				IWL_DEBUG_RF_KILL(trans,
						  "Rfkill while SYNC HCMD in flight\n");
			wake_up(&trans_pcie->wait_command_queue);
		} else {
			clear_bit(STATUS_RFKILL, &trans_pcie->status);
		}

		handled |= CSR_INT_BIT_RF_KILL;
	}

	/* Chip got too hot and stopped itself */
	if (inta & CSR_INT_BIT_CT_KILL) {
		IWL_ERR(trans, "Microcode CT kill error detected.\n");
		isr_stats->ctkill++;
		handled |= CSR_INT_BIT_CT_KILL;
	}

	/* Error detected by uCode */
	if (inta & CSR_INT_BIT_SW_ERR) {
		IWL_ERR(trans, "Microcode SW error detected. "
			" Restarting 0x%X.\n", inta);
		isr_stats->sw++;
		iwl_pcie_irq_handle_error(trans);
		handled |= CSR_INT_BIT_SW_ERR;
	}

	/* uCode wakes up after power-down sleep */
	if (inta & CSR_INT_BIT_WAKEUP) {
		IWL_DEBUG_ISR(trans, "Wakeup interrupt\n");
		iwl_pcie_rxq_inc_wr_ptr(trans, &trans_pcie->rxq);
		for (i = 0; i < trans->cfg->base_params->num_of_queues; i++)
			iwl_pcie_txq_inc_wr_ptr(trans, &trans_pcie->txq[i]);

		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(trans, "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(trans, CSR_FH_INT_STATUS,
					CSR_FH_INT_RX_MASK);
		}
		if (inta & CSR_INT_BIT_RX_PERIODIC) {
			handled |= CSR_INT_BIT_RX_PERIODIC;
			iwl_write32(trans,
				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(trans, CSR_INT_PERIODIC_REG,
			    CSR_INT_PERIODIC_DIS);

		iwl_pcie_rx_handle(trans);

		/*
		 * 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(trans, CSR_INT_PERIODIC_REG,
				   CSR_INT_PERIODIC_ENA);

		isr_stats->rx++;
	}

	/* This "Tx" DMA channel is used only for loading uCode */
	if (inta & CSR_INT_BIT_FH_TX) {
		iwl_write32(trans, CSR_FH_INT_STATUS, CSR_FH_INT_TX_MASK);
		IWL_DEBUG_ISR(trans, "uCode load interrupt\n");
		isr_stats->tx++;
		handled |= CSR_INT_BIT_FH_TX;
		/* Wake up uCode load routine, now that load is complete */
		trans_pcie->ucode_write_complete = true;
		wake_up(&trans_pcie->ucode_write_waitq);
	}

	if (inta & ~handled) {
		IWL_ERR(trans, "Unhandled INTA bits 0x%08x\n", inta & ~handled);
		isr_stats->unhandled++;
	}

	if (inta & ~(trans_pcie->inta_mask)) {
		IWL_WARN(trans, "Disabled INTA bits 0x%08x were pending\n",
			 inta & ~trans_pcie->inta_mask);
	}

	/* Re-enable all interrupts */
	/* only Re-enable if disabled by irq */
	if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status))
		iwl_enable_interrupts(trans);
	/* Re-enable RF_KILL if it occurred */
	else if (handled & CSR_INT_BIT_RF_KILL)
		iwl_enable_rfkill_int(trans);

out:
	lock_map_release(&trans->sync_cmd_lockdep_map);
	return IRQ_HANDLED;
}

/******************************************************************************
 *
 * ICT functions
 *
 ******************************************************************************/

/* a device (PCI-E) page is 4096 bytes long */
#define ICT_SHIFT	12
#define ICT_SIZE	(1 << ICT_SHIFT)
#define ICT_COUNT	(ICT_SIZE / sizeof(u32))

/* Free dram table */
void iwl_pcie_free_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	if (trans_pcie->ict_tbl) {
		dma_free_coherent(trans->dev, ICT_SIZE,
				  trans_pcie->ict_tbl,
				  trans_pcie->ict_tbl_dma);
		trans_pcie->ict_tbl = NULL;
		trans_pcie->ict_tbl_dma = 0;
	}
}

/*
 * allocate dram shared table, it is an aligned memory
 * block of ICT_SIZE.
 * also reset all data related to ICT table interrupt.
 */
int iwl_pcie_alloc_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	trans_pcie->ict_tbl =
		dma_alloc_coherent(trans->dev, ICT_SIZE,
				   &trans_pcie->ict_tbl_dma,
				   GFP_KERNEL);
	if (!trans_pcie->ict_tbl)
		return -ENOMEM;

	/* just an API sanity check ... it is guaranteed to be aligned */
	if (WARN_ON(trans_pcie->ict_tbl_dma & (ICT_SIZE - 1))) {
		iwl_pcie_free_ict(trans);
		return -EINVAL;
	}

	IWL_DEBUG_ISR(trans, "ict dma addr %Lx\n",
		      (unsigned long long)trans_pcie->ict_tbl_dma);

	IWL_DEBUG_ISR(trans, "ict vir addr %p\n", trans_pcie->ict_tbl);

	/* reset table and index to all 0 */
	memset(trans_pcie->ict_tbl, 0, ICT_SIZE);
	trans_pcie->ict_index = 0;

	/* add periodic RX interrupt */
	trans_pcie->inta_mask |= CSR_INT_BIT_RX_PERIODIC;
	return 0;
}

/* Device is going up inform it about using ICT interrupt table,
 * also we need to tell the driver to start using ICT interrupt.
 */
void iwl_pcie_reset_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	u32 val;
	unsigned long flags;

	if (!trans_pcie->ict_tbl)
		return;

	spin_lock_irqsave(&trans_pcie->irq_lock, flags);
	iwl_disable_interrupts(trans);

	memset(trans_pcie->ict_tbl, 0, ICT_SIZE);

	val = trans_pcie->ict_tbl_dma >> ICT_SHIFT;

	val |= CSR_DRAM_INT_TBL_ENABLE;
	val |= CSR_DRAM_INIT_TBL_WRAP_CHECK;

	IWL_DEBUG_ISR(trans, "CSR_DRAM_INT_TBL_REG =0x%x\n", val);

	iwl_write32(trans, CSR_DRAM_INT_TBL_REG, val);
	trans_pcie->use_ict = true;
	trans_pcie->ict_index = 0;
	iwl_write32(trans, CSR_INT, trans_pcie->inta_mask);
	iwl_enable_interrupts(trans);
	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
}

/* Device is going down disable ict interrupt usage */
void iwl_pcie_disable_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	unsigned long flags;

	spin_lock_irqsave(&trans_pcie->irq_lock, flags);
	trans_pcie->use_ict = false;
	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
}

/* legacy (non-ICT) ISR. Assumes that trans_pcie->irq_lock is held */
static irqreturn_t iwl_pcie_isr(int irq, void *data)
{
	struct iwl_trans *trans = data;
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	u32 inta, inta_mask;
#ifdef CPTCFG_IWLWIFI_DEBUG
	u32 inta_fh;
#endif

	lockdep_assert_held(&trans_pcie->irq_lock);

	trace_iwlwifi_dev_irq(trans->dev);

	/* Disable (but don't clear!) interrupts here to avoid
	 *    back-to-back ISRs and sporadic interrupts from our NIC.
	 * If we have something to service, the irq thread will re-enable ints.
	 * If we *don't* have something, we'll re-enable before leaving here. */
	inta_mask = iwl_read32(trans, CSR_INT_MASK);
	iwl_write32(trans, CSR_INT_MASK, 0x00000000);

	/* Discover which interrupts are active/pending */
	inta = iwl_read32(trans, CSR_INT);

	if (inta & (~inta_mask)) {
		IWL_DEBUG_ISR(trans,
			      "We got a masked interrupt (0x%08x)...Ack and ignore\n",
			      inta & (~inta_mask));
		iwl_write32(trans, CSR_INT, inta & (~inta_mask));
		inta &= inta_mask;
	}

	/* Ignore interrupt if there's nothing in NIC to service.
	 * This may be due to IRQ shared with another device,
	 * or due to sporadic interrupts thrown from our NIC. */
	if (!inta) {
		IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n");
		goto none;
	}

	if ((inta == 0xFFFFFFFF) || ((inta & 0xFFFFFFF0) == 0xa5a5a5a0)) {
		/* Hardware disappeared. It might have already raised
		 * an interrupt */
		IWL_WARN(trans, "HARDWARE GONE?? INTA == 0x%08x\n", inta);
		return IRQ_HANDLED;
	}

#ifdef CPTCFG_IWLWIFI_DEBUG
	if (iwl_have_debug_level(IWL_DL_ISR)) {
		inta_fh = iwl_read32(trans, CSR_FH_INT_STATUS);
		IWL_DEBUG_ISR(trans, "ISR inta 0x%08x, enabled 0x%08x, "
			      "fh 0x%08x\n", inta, inta_mask, inta_fh);
	}
#endif

	trans_pcie->inta |= inta;
	/* the thread will service interrupts and re-enable them */
	if (likely(inta))
		return IRQ_WAKE_THREAD;
	else if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
		 !trans_pcie->inta)
		iwl_enable_interrupts(trans);
	return IRQ_HANDLED;

none:
	/* re-enable interrupts here since we don't have anything to service. */
	/* only Re-enable if disabled by irq  and no schedules tasklet. */
	if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
	    !trans_pcie->inta)
		iwl_enable_interrupts(trans);

	return IRQ_NONE;
}

/* interrupt handler using ict table, with this interrupt driver will
 * stop using INTA register to get device's interrupt, reading this register
 * is expensive, device will write interrupts in ICT dram table, increment
 * index then will fire interrupt to driver, driver will OR all ICT table
 * entries from current index up to table entry with 0 value. the result is
 * the interrupt we need to service, driver will set the entries back to 0 and
 * set index.
 */
irqreturn_t iwl_pcie_isr_ict(int irq, void *data)
{
	struct iwl_trans *trans = data;
	struct iwl_trans_pcie *trans_pcie;
	u32 inta, inta_mask;
	u32 val = 0;
	u32 read;
	unsigned long flags;

	if (!trans)
		return IRQ_NONE;

	trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	spin_lock_irqsave(&trans_pcie->irq_lock, flags);

	/* dram interrupt table not set yet,
	 * use legacy interrupt.
	 */
	if (unlikely(!trans_pcie->use_ict)) {
		irqreturn_t ret = iwl_pcie_isr(irq, data);
		spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
		return ret;
	}

	trace_iwlwifi_dev_irq(trans->dev);

	/* Disable (but don't clear!) interrupts here to avoid
	 * back-to-back ISRs and sporadic interrupts from our NIC.
	 * If we have something to service, the tasklet will re-enable ints.
	 * If we *don't* have something, we'll re-enable before leaving here.
	 */
	inta_mask = iwl_read32(trans, CSR_INT_MASK);
	iwl_write32(trans, CSR_INT_MASK, 0x00000000);

	/* Ignore interrupt if there's nothing in NIC to service.
	 * This may be due to IRQ shared with another device,
	 * or due to sporadic interrupts thrown from our NIC. */
	read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
	trace_iwlwifi_dev_ict_read(trans->dev, trans_pcie->ict_index, read);
	if (!read) {
		IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n");
		goto none;
	}

	/*
	 * Collect all entries up to the first 0, starting from ict_index;
	 * note we already read at ict_index.
	 */
	do {
		val |= read;
		IWL_DEBUG_ISR(trans, "ICT index %d value 0x%08X\n",
				trans_pcie->ict_index, read);
		trans_pcie->ict_tbl[trans_pcie->ict_index] = 0;
		trans_pcie->ict_index =
			iwl_queue_inc_wrap(trans_pcie->ict_index, ICT_COUNT);

		read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
		trace_iwlwifi_dev_ict_read(trans->dev, trans_pcie->ict_index,
					   read);
	} while (read);

	/* We should not get this value, just ignore it. */
	if (val == 0xffffffff)
		val = 0;

	/*
	 * this is a w/a for a h/w bug. the h/w bug may cause the Rx bit
	 * (bit 15 before shifting it to 31) to clear when using interrupt
	 * coalescing. fortunately, bits 18 and 19 stay set when this happens
	 * so we use them to decide on the real state of the Rx bit.
	 * In order words, bit 15 is set if bit 18 or bit 19 are set.
	 */
	if (val & 0xC0000)
		val |= 0x8000;

	inta = (0xff & val) | ((0xff00 & val) << 16);
	IWL_DEBUG_ISR(trans, "ISR inta 0x%08x, enabled 0x%08x ict 0x%08x\n",
		      inta, inta_mask, val);

	inta &= trans_pcie->inta_mask;
	trans_pcie->inta |= inta;

	/* iwl_pcie_tasklet() will service interrupts and re-enable them */
	if (likely(inta)) {
		spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
		return IRQ_WAKE_THREAD;
	} else if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
		 !trans_pcie->inta) {
		/* Allow interrupt if was disabled by this handler and
		 * no tasklet was schedules, We should not enable interrupt,
		 * tasklet will enable it.
		 */
		iwl_enable_interrupts(trans);
	}

	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
	return IRQ_HANDLED;

 none:
	/* re-enable interrupts here since we don't have anything to service.
	 * only Re-enable if disabled by irq.
	 */
	if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
	    !trans_pcie->inta)
		iwl_enable_interrupts(trans);

	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
	return IRQ_NONE;
}
示例#2
0
文件: rx.c 项目: andy-shev/linux
static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
				struct iwl_rx_mem_buffer *rxb,
				bool emergency)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	struct iwl_txq *txq = &trans_pcie->txq[trans_pcie->cmd_queue];
	bool page_stolen = false;
	int max_len = PAGE_SIZE << trans_pcie->rx_page_order;
	u32 offset = 0;

	if (WARN_ON(!rxb))
		return;

	dma_unmap_page(trans->dev, rxb->page_dma, max_len, DMA_FROM_DEVICE);

	while (offset + sizeof(u32) + sizeof(struct iwl_cmd_header) < max_len) {
		struct iwl_rx_packet *pkt;
		u16 sequence;
		bool reclaim;
		int index, cmd_index, len;
		struct iwl_rx_cmd_buffer rxcb = {
			._offset = offset,
			._rx_page_order = trans_pcie->rx_page_order,
			._page = rxb->page,
			._page_stolen = false,
			.truesize = max_len,
		};

		pkt = rxb_addr(&rxcb);

		if (pkt->len_n_flags == cpu_to_le32(FH_RSCSR_FRAME_INVALID))
			break;

		IWL_DEBUG_RX(trans,
			     "cmd at offset %d: %s (0x%.2x, seq 0x%x)\n",
			     rxcb._offset,
			     iwl_get_cmd_string(trans,
						iwl_cmd_id(pkt->hdr.cmd,
							   pkt->hdr.group_id,
							   0)),
			     pkt->hdr.cmd, le16_to_cpu(pkt->hdr.sequence));

		len = iwl_rx_packet_len(pkt);
		len += sizeof(u32); /* account for status word */
		trace_iwlwifi_dev_rx(trans->dev, trans, pkt, len);
		trace_iwlwifi_dev_rx_data(trans->dev, trans, 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);
		if (reclaim) {
			int i;

			for (i = 0; i < trans_pcie->n_no_reclaim_cmds; i++) {
				if (trans_pcie->no_reclaim_cmds[i] ==
							pkt->hdr.cmd) {
					reclaim = false;
					break;
				}
			}
		}

		sequence = le16_to_cpu(pkt->hdr.sequence);
		index = SEQ_TO_INDEX(sequence);
		cmd_index = get_cmd_index(&txq->q, index);

		iwl_op_mode_rx(trans->op_mode, &trans_pcie->napi, &rxcb);

		if (reclaim) {
			kzfree(txq->entries[cmd_index].free_buf);
			txq->entries[cmd_index].free_buf = NULL;
		}

		/*
		 * After here, we should always check rxcb._page_stolen,
		 * if it is true then one of the handlers took the page.
		 */

		if (reclaim) {
			/* Invoke any callbacks, transfer the buffer to caller,
			 * and fire off the (possibly) blocking
			 * iwl_trans_send_cmd()
			 * as we reclaim the driver command queue */
			if (!rxcb._page_stolen)
				iwl_pcie_hcmd_complete(trans, &rxcb);
			else
				IWL_WARN(trans, "Claim null rxb?\n");
		}

		page_stolen |= rxcb._page_stolen;
		offset += ALIGN(len, FH_RSCSR_FRAME_ALIGN);
	}

	/* page was stolen from us -- free our reference */
	if (page_stolen) {
		__free_pages(rxb->page, trans_pcie->rx_page_order);
		rxb->page = NULL;
	}

	/* 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. */
	if (rxb->page != NULL) {
		rxb->page_dma =
			dma_map_page(trans->dev, rxb->page, 0,
				     PAGE_SIZE << trans_pcie->rx_page_order,
				     DMA_FROM_DEVICE);
		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
			/*
			 * free the page(s) as well to not break
			 * the invariant that the items on the used
			 * list have no page(s)
			 */
			__free_pages(rxb->page, trans_pcie->rx_page_order);
			rxb->page = NULL;
			iwl_pcie_rx_reuse_rbd(trans, rxb, rxq, emergency);
		} else {
			list_add_tail(&rxb->list, &rxq->rx_free);
			rxq->free_count++;
		}
	} else
		iwl_pcie_rx_reuse_rbd(trans, rxb, rxq, emergency);
}

/*
 * iwl_pcie_rx_handle - Main entry function for receiving responses from fw
 */
static void iwl_pcie_rx_handle(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	u32 r, i, j, count = 0;
	bool emergency = false;

restart:
	spin_lock(&rxq->lock);
	/* 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(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
	i = rxq->read;

	/* Rx interrupt, but nothing sent from uCode */
	if (i == r)
		IWL_DEBUG_RX(trans, "HW = SW = %d\n", r);

	while (i != r) {
		struct iwl_rx_mem_buffer *rxb;

		if (unlikely(rxq->used_count == RX_QUEUE_SIZE / 2))
			emergency = true;

		rxb = rxq->queue[i];
		rxq->queue[i] = NULL;

		IWL_DEBUG_RX(trans, "rxbuf: HW = %d, SW = %d\n", r, i);
		iwl_pcie_rx_handle_rb(trans, rxb, emergency);

		i = (i + 1) & RX_QUEUE_MASK;

		/* If we have RX_CLAIM_REQ_ALLOC released rx buffers -
		 * try to claim the pre-allocated buffers from the allocator */
		if (rxq->used_count >= RX_CLAIM_REQ_ALLOC) {
			struct iwl_rb_allocator *rba = &trans_pcie->rba;
			struct iwl_rx_mem_buffer *out[RX_CLAIM_REQ_ALLOC];

			if (rxq->used_count % RX_CLAIM_REQ_ALLOC == 0 &&
			    !emergency) {
				/* Add the remaining 6 empty RBDs
				* for allocator use
				 */
				spin_lock(&rba->lock);
				list_splice_tail_init(&rxq->rx_used,
						      &rba->rbd_empty);
				spin_unlock(&rba->lock);
			}

			/* If not ready - continue, will try to reclaim later.
			* No need to reschedule work - allocator exits only on
			* success */
			if (!iwl_pcie_rx_allocator_get(trans, out)) {
				/* If success - then RX_CLAIM_REQ_ALLOC
				 * buffers were retrieved and should be added
				 * to free list */
				rxq->used_count -= RX_CLAIM_REQ_ALLOC;
				for (j = 0; j < RX_CLAIM_REQ_ALLOC; j++) {
					list_add_tail(&out[j]->list,
						      &rxq->rx_free);
					rxq->free_count++;
				}
			}
		}
		if (emergency) {
			count++;
			if (count == 8) {
				count = 0;
				if (rxq->used_count < RX_QUEUE_SIZE / 3)
					emergency = false;
				spin_unlock(&rxq->lock);
				iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC);
				spin_lock(&rxq->lock);
			}
		}
		/* handle restock for three cases, can be all of them at once:
		* - we just pulled buffers from the allocator
		* - we have 8+ unstolen pages accumulated
		* - we are in emergency and allocated buffers
		 */
		if (rxq->free_count >=  RX_CLAIM_REQ_ALLOC) {
			rxq->read = i;
			spin_unlock(&rxq->lock);
			iwl_pcie_rxq_restock(trans);
			goto restart;
		}
	}

	/* Backtrack one entry */
	rxq->read = i;
	spin_unlock(&rxq->lock);

	/*
	 * handle a case where in emergency there are some unallocated RBDs.
	 * those RBDs are in the used list, but are not tracked by the queue's
	 * used_count which counts allocator owned RBDs.
	 * unallocated emergency RBDs must be allocated on exit, otherwise
	 * when called again the function may not be in emergency mode and
	 * they will be handed to the allocator with no tracking in the RBD
	 * allocator counters, which will lead to them never being claimed back
	 * by the queue.
	 * by allocating them here, they are now in the queue free list, and
	 * will be restocked by the next call of iwl_pcie_rxq_restock.
	 */
	if (unlikely(emergency && count))
		iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC);

	if (trans_pcie->napi.poll)
		napi_gro_flush(&trans_pcie->napi, false);
}

/*
 * iwl_pcie_irq_handle_error - called for HW or SW error interrupt from card
 */
static void iwl_pcie_irq_handle_error(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	int i;

	/* W/A for WiFi/WiMAX coex and WiMAX own the RF */
	if (trans->cfg->internal_wimax_coex &&
	    !trans->cfg->apmg_not_supported &&
	    (!(iwl_read_prph(trans, APMG_CLK_CTRL_REG) &
			     APMS_CLK_VAL_MRB_FUNC_MODE) ||
	     (iwl_read_prph(trans, APMG_PS_CTRL_REG) &
			    APMG_PS_CTRL_VAL_RESET_REQ))) {
		clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
		iwl_op_mode_wimax_active(trans->op_mode);
		wake_up(&trans_pcie->wait_command_queue);
		return;
	}

	iwl_pcie_dump_csr(trans);
	iwl_dump_fh(trans, NULL);

	local_bh_disable();
	/* The STATUS_FW_ERROR bit is set in this function. This must happen
	 * before we wake up the command caller, to ensure a proper cleanup. */
	iwl_trans_fw_error(trans);
	local_bh_enable();

	for (i = 0; i < trans->cfg->base_params->num_of_queues; i++)
		del_timer(&trans_pcie->txq[i].stuck_timer);

	clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
	wake_up(&trans_pcie->wait_command_queue);
}

static u32 iwl_pcie_int_cause_non_ict(struct iwl_trans *trans)
{
	u32 inta;

	lockdep_assert_held(&IWL_TRANS_GET_PCIE_TRANS(trans)->irq_lock);

	trace_iwlwifi_dev_irq(trans->dev);

	/* Discover which interrupts are active/pending */
	inta = iwl_read32(trans, CSR_INT);

	/* the thread will service interrupts and re-enable them */
	return inta;
}
示例#3
0
文件: rx.c 项目: 383530895/linux
static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
				struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	struct iwl_txq *txq = &trans_pcie->txq[trans_pcie->cmd_queue];
	bool page_stolen = false;
	int max_len = PAGE_SIZE << trans_pcie->rx_page_order;
	u32 offset = 0;

	if (WARN_ON(!rxb))
		return;

	dma_unmap_page(trans->dev, rxb->page_dma, max_len, DMA_FROM_DEVICE);

	while (offset + sizeof(u32) + sizeof(struct iwl_cmd_header) < max_len) {
		struct iwl_rx_packet *pkt;
		struct iwl_device_cmd *cmd;
		u16 sequence;
		bool reclaim;
		int index, cmd_index, err, len;
		struct iwl_rx_cmd_buffer rxcb = {
			._offset = offset,
			._rx_page_order = trans_pcie->rx_page_order,
			._page = rxb->page,
			._page_stolen = false,
			.truesize = max_len,
		};

		pkt = rxb_addr(&rxcb);

		if (pkt->len_n_flags == cpu_to_le32(FH_RSCSR_FRAME_INVALID))
			break;

		IWL_DEBUG_RX(trans, "cmd at offset %d: %s (0x%.2x)\n",
			rxcb._offset, get_cmd_string(trans_pcie, pkt->hdr.cmd),
			pkt->hdr.cmd);

		len = iwl_rx_packet_len(pkt);
		len += sizeof(u32); /* account for status word */
		trace_iwlwifi_dev_rx(trans->dev, trans, pkt, len);
		trace_iwlwifi_dev_rx_data(trans->dev, trans, 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);
		if (reclaim) {
			int i;

			for (i = 0; i < trans_pcie->n_no_reclaim_cmds; i++) {
				if (trans_pcie->no_reclaim_cmds[i] ==
							pkt->hdr.cmd) {
					reclaim = false;
					break;
				}
			}
		}

		sequence = le16_to_cpu(pkt->hdr.sequence);
		index = SEQ_TO_INDEX(sequence);
		cmd_index = get_cmd_index(&txq->q, index);

		if (reclaim)
			cmd = txq->entries[cmd_index].cmd;
		else
			cmd = NULL;

		err = iwl_op_mode_rx(trans->op_mode, &rxcb, cmd);

		if (reclaim) {
			kzfree(txq->entries[cmd_index].free_buf);
			txq->entries[cmd_index].free_buf = NULL;
		}

		/*
		 * After here, we should always check rxcb._page_stolen,
		 * if it is true then one of the handlers took the page.
		 */

		if (reclaim) {
			/* Invoke any callbacks, transfer the buffer to caller,
			 * and fire off the (possibly) blocking
			 * iwl_trans_send_cmd()
			 * as we reclaim the driver command queue */
			if (!rxcb._page_stolen)
				iwl_pcie_hcmd_complete(trans, &rxcb, err);
			else
				IWL_WARN(trans, "Claim null rxb?\n");
		}

		page_stolen |= rxcb._page_stolen;
		offset += ALIGN(len, FH_RSCSR_FRAME_ALIGN);
	}

	/* page was stolen from us -- free our reference */
	if (page_stolen) {
		__free_pages(rxb->page, trans_pcie->rx_page_order);
		rxb->page = NULL;
	}

	/* 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. */
	if (rxb->page != NULL) {
		rxb->page_dma =
			dma_map_page(trans->dev, rxb->page, 0,
				     PAGE_SIZE << trans_pcie->rx_page_order,
				     DMA_FROM_DEVICE);
		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
			/*
			 * free the page(s) as well to not break
			 * the invariant that the items on the used
			 * list have no page(s)
			 */
			__free_pages(rxb->page, trans_pcie->rx_page_order);
			rxb->page = NULL;
			list_add_tail(&rxb->list, &rxq->rx_used);
		} else {
			list_add_tail(&rxb->list, &rxq->rx_free);
			rxq->free_count++;
		}
	} else
		list_add_tail(&rxb->list, &rxq->rx_used);
}

/*
 * iwl_pcie_rx_handle - Main entry function for receiving responses from fw
 */
static void iwl_pcie_rx_handle(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	u32 r, i;
	u8 fill_rx = 0;
	u32 count = 8;
	int total_empty;

restart:
	spin_lock(&rxq->lock);
	/* 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(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
	i = rxq->read;

	/* Rx interrupt, but nothing sent from uCode */
	if (i == r)
		IWL_DEBUG_RX(trans, "HW = SW = %d\n", r);

	/* 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) {
		struct iwl_rx_mem_buffer *rxb;

		rxb = rxq->queue[i];
		rxq->queue[i] = NULL;

		IWL_DEBUG_RX(trans, "rxbuf: HW = %d, SW = %d (%p)\n",
			     r, i, rxb);
		iwl_pcie_rx_handle_rb(trans, rxb);

		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;
				spin_unlock(&rxq->lock);
				iwl_pcie_rx_replenish(trans, GFP_ATOMIC);
				count = 0;
				goto restart;
			}
		}
	}

	/* Backtrack one entry */
	rxq->read = i;
	spin_unlock(&rxq->lock);

	if (fill_rx)
		iwl_pcie_rx_replenish(trans, GFP_ATOMIC);
	else
		iwl_pcie_rxq_restock(trans);

	if (trans_pcie->napi.poll)
		napi_gro_flush(&trans_pcie->napi, false);
}

/*
 * iwl_pcie_irq_handle_error - called for HW or SW error interrupt from card
 */
static void iwl_pcie_irq_handle_error(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	/* W/A for WiFi/WiMAX coex and WiMAX own the RF */
	if (trans->cfg->internal_wimax_coex &&
	    (!(iwl_read_prph(trans, APMG_CLK_CTRL_REG) &
			     APMS_CLK_VAL_MRB_FUNC_MODE) ||
	     (iwl_read_prph(trans, APMG_PS_CTRL_REG) &
			    APMG_PS_CTRL_VAL_RESET_REQ))) {
		clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
		iwl_op_mode_wimax_active(trans->op_mode);
		wake_up(&trans_pcie->wait_command_queue);
		return;
	}

	iwl_pcie_dump_csr(trans);
	iwl_dump_fh(trans, NULL);

	local_bh_disable();
	/* The STATUS_FW_ERROR bit is set in this function. This must happen
	 * before we wake up the command caller, to ensure a proper cleanup. */
	iwl_trans_fw_error(trans);
	local_bh_enable();

	clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
	wake_up(&trans_pcie->wait_command_queue);
}

static u32 iwl_pcie_int_cause_non_ict(struct iwl_trans *trans)
{
	u32 inta;

	lockdep_assert_held(&IWL_TRANS_GET_PCIE_TRANS(trans)->irq_lock);

	trace_iwlwifi_dev_irq(trans->dev);

	/* Discover which interrupts are active/pending */
	inta = iwl_read32(trans, CSR_INT);

	/* the thread will service interrupts and re-enable them */
	return inta;
}
示例#4
0
static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
				struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	struct iwl_txq *txq = &trans_pcie->txq[trans_pcie->cmd_queue];
	unsigned long flags;
	bool page_stolen = false;
	int max_len = PAGE_SIZE << trans_pcie->rx_page_order;
	u32 offset = 0;

	if (WARN_ON(!rxb))
		return;

	dma_unmap_page(trans->dev, rxb->page_dma, max_len, DMA_FROM_DEVICE);

	while (offset + sizeof(u32) + sizeof(struct iwl_cmd_header) < max_len) {
		struct iwl_rx_packet *pkt;
		struct iwl_device_cmd *cmd;
		u16 sequence;
		bool reclaim;
		int index, cmd_index, err, len;
		struct iwl_rx_cmd_buffer rxcb = {
			._offset = offset,
			._rx_page_order = trans_pcie->rx_page_order,
			._page = rxb->page,
			._page_stolen = false,
			.truesize = max_len,
		};

		pkt = rxb_addr(&rxcb);

		if (pkt->len_n_flags == cpu_to_le32(FH_RSCSR_FRAME_INVALID))
			break;

		IWL_DEBUG_RX(trans, "cmd at offset %d: %s (0x%.2x)\n",
			rxcb._offset, get_cmd_string(trans_pcie, 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(trans->dev, trans, pkt, len);
		trace_iwlwifi_dev_rx_data(trans->dev, trans, 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);
		if (reclaim) {
			int i;

			for (i = 0; i < trans_pcie->n_no_reclaim_cmds; i++) {
				if (trans_pcie->no_reclaim_cmds[i] ==
							pkt->hdr.cmd) {
					reclaim = false;
					break;
				}
			}
		}

		sequence = le16_to_cpu(pkt->hdr.sequence);
		index = SEQ_TO_INDEX(sequence);
		cmd_index = get_cmd_index(&txq->q, index);

		if (reclaim)
			cmd = txq->entries[cmd_index].cmd;
		else
			cmd = NULL;

		err = iwl_op_mode_rx(trans->op_mode, &rxcb, cmd);

		if (reclaim) {
			kfree(txq->entries[cmd_index].free_buf);
			txq->entries[cmd_index].free_buf = NULL;
		}

		/*
		 * After here, we should always check rxcb._page_stolen,
		 * if it is true then one of the handlers took the page.
		 */

		if (reclaim) {
			/* Invoke any callbacks, transfer the buffer to caller,
			 * and fire off the (possibly) blocking
			 * iwl_trans_send_cmd()
			 * as we reclaim the driver command queue */
			if (!rxcb._page_stolen)
				iwl_pcie_hcmd_complete(trans, &rxcb, err);
			else
				IWL_WARN(trans, "Claim null rxb?\n");
		}

		page_stolen |= rxcb._page_stolen;
		offset += ALIGN(len, FH_RSCSR_FRAME_ALIGN);
	}

	/* page was stolen from us -- free our reference */
	if (page_stolen) {
		__free_pages(rxb->page, trans_pcie->rx_page_order);
		rxb->page = NULL;
	}

	/* 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(trans->dev, rxb->page, 0,
				     PAGE_SIZE << trans_pcie->rx_page_order,
				     DMA_FROM_DEVICE);
		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
			/*
			 * free the page(s) as well to not break
			 * the invariant that the items on the used
			 * list have no page(s)
			 */
			__free_pages(rxb->page, trans_pcie->rx_page_order);
			rxb->page = NULL;
			list_add_tail(&rxb->list, &rxq->rx_used);
		} else {
			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);
}

/*
 * iwl_pcie_rx_handle - Main entry function for receiving responses from fw
 */
static void iwl_pcie_rx_handle(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq;
	u32 r, i;
	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(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
	i = rxq->read;

	/* Rx interrupt, but nothing sent from uCode */
	if (i == r)
		IWL_DEBUG_RX(trans, "HW = SW = %d\n", r);

	/* 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) {
		struct iwl_rx_mem_buffer *rxb;

		rxb = rxq->queue[i];
		rxq->queue[i] = NULL;

		IWL_DEBUG_RX(trans, "rxbuf: HW = %d, SW = %d (%p)\n",
			     r, i, rxb);
		iwl_pcie_rx_handle_rb(trans, rxb);

		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;
				iwl_pcie_rx_replenish_now(trans);
				count = 0;
			}
		}
	}

	/* Backtrack one entry */
	rxq->read = i;
	if (fill_rx)
		iwl_pcie_rx_replenish_now(trans);
	else
		iwl_pcie_rxq_restock(trans);
}

/*
 * iwl_pcie_irq_handle_error - called for HW or SW error interrupt from card
 */
static void iwl_pcie_irq_handle_error(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	/* W/A for WiFi/WiMAX coex and WiMAX own the RF */
	if (trans->cfg->internal_wimax_coex &&
	    (!(iwl_read_prph(trans, APMG_CLK_CTRL_REG) &
			     APMS_CLK_VAL_MRB_FUNC_MODE) ||
	     (iwl_read_prph(trans, APMG_PS_CTRL_REG) &
			    APMG_PS_CTRL_VAL_RESET_REQ))) {
		clear_bit(STATUS_HCMD_ACTIVE, &trans_pcie->status);
		iwl_op_mode_wimax_active(trans->op_mode);
		wake_up(&trans_pcie->wait_command_queue);
		return;
	}

	iwl_pcie_dump_csr(trans);
	iwl_pcie_dump_fh(trans, NULL);

	set_bit(STATUS_FW_ERROR, &trans_pcie->status);
	clear_bit(STATUS_HCMD_ACTIVE, &trans_pcie->status);
	wake_up(&trans_pcie->wait_command_queue);

	local_bh_disable();
	iwl_op_mode_nic_error(trans->op_mode);
	local_bh_enable();
}

irqreturn_t iwl_pcie_irq_handler(int irq, void *dev_id)
{
	struct iwl_trans *trans = dev_id;
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct isr_statistics *isr_stats = &trans_pcie->isr_stats;
	u32 inta = 0;
	u32 handled = 0;
	unsigned long flags;
	u32 i;
#ifdef CONFIG_IWLWIFI_DEBUG
	u32 inta_mask;
#endif

	lock_map_acquire(&trans->sync_cmd_lockdep_map);

	spin_lock_irqsave(&trans_pcie->irq_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(trans, CSR_INT,
		    trans_pcie->inta | ~trans_pcie->inta_mask);

	inta = trans_pcie->inta;

#ifdef CONFIG_IWLWIFI_DEBUG
	if (iwl_have_debug_level(IWL_DL_ISR)) {
		/* just for debug */
		inta_mask = iwl_read32(trans, CSR_INT_MASK);
		IWL_DEBUG_ISR(trans, "inta 0x%08x, enabled 0x%08x\n",
			      inta, inta_mask);
	}
#endif

	/* saved interrupt in inta variable now we can reset trans_pcie->inta */
	trans_pcie->inta = 0;

	spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);

	/* Now service all interrupt bits discovered above. */
	if (inta & CSR_INT_BIT_HW_ERR) {
		IWL_ERR(trans, "Hardware error detected.  Restarting.\n");

		/* Tell the device to stop sending interrupts */
		iwl_disable_interrupts(trans);

		isr_stats->hw++;
		iwl_pcie_irq_handle_error(trans);

		handled |= CSR_INT_BIT_HW_ERR;

		goto out;
	}

#ifdef CONFIG_IWLWIFI_DEBUG
	if (iwl_have_debug_level(IWL_DL_ISR)) {
		/* NIC fires this, but we don't use it, redundant with WAKEUP */
		if (inta & CSR_INT_BIT_SCD) {
			IWL_DEBUG_ISR(trans, "Scheduler finished to transmit "
				      "the frame/frames.\n");
			isr_stats->sch++;
		}

		/* Alive notification via Rx interrupt will do the real work */
		if (inta & CSR_INT_BIT_ALIVE) {
			IWL_DEBUG_ISR(trans, "Alive interrupt\n");
			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) {
		bool hw_rfkill;

		hw_rfkill = iwl_is_rfkill_set(trans);
		IWL_WARN(trans, "RF_KILL bit toggled to %s.\n",
			 hw_rfkill ? "disable radio" : "enable radio");

		isr_stats->rfkill++;

		iwl_op_mode_hw_rf_kill(trans->op_mode, hw_rfkill);
		if (hw_rfkill) {
			set_bit(STATUS_RFKILL, &trans_pcie->status);
			if (test_and_clear_bit(STATUS_HCMD_ACTIVE,
					       &trans_pcie->status))
				IWL_DEBUG_RF_KILL(trans,
						  "Rfkill while SYNC HCMD in flight\n");
			wake_up(&trans_pcie->wait_command_queue);
		} else {
			clear_bit(STATUS_RFKILL, &trans_pcie->status);
		}

		handled |= CSR_INT_BIT_RF_KILL;
	}

	/* Chip got too hot and stopped itself */
	if (inta & CSR_INT_BIT_CT_KILL) {
		IWL_ERR(trans, "Microcode CT kill error detected.\n");
		isr_stats->ctkill++;
		handled |= CSR_INT_BIT_CT_KILL;
	}

	/* Error detected by uCode */
	if (inta & CSR_INT_BIT_SW_ERR) {
		IWL_ERR(trans, "Microcode SW error detected. "
			" Restarting 0x%X.\n", inta);
		isr_stats->sw++;
		iwl_pcie_irq_handle_error(trans);
		handled |= CSR_INT_BIT_SW_ERR;
	}

	/* uCode wakes up after power-down sleep */
	if (inta & CSR_INT_BIT_WAKEUP) {
		IWL_DEBUG_ISR(trans, "Wakeup interrupt\n");
		iwl_pcie_rxq_inc_wr_ptr(trans, &trans_pcie->rxq);
		for (i = 0; i < trans->cfg->base_params->num_of_queues; i++)
			iwl_pcie_txq_inc_wr_ptr(trans, &trans_pcie->txq[i]);

		isr_stats->wakeup++;