iwlwifi: move under intel vendor directory

Part of reorganising wireless drivers directory and Kconfig.

Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 1548 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
new file mode 100644
index 000000000000..e06591f625c4
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -0,0 +1,1548 @@
+/******************************************************************************
+ *
+ * Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved.
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
+ *
+ * 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/sched.h>
+#include <linux/wait.h>
+#include <linux/gfp.h>
+
+#include "iwl-prph.h"
+#include "iwl-io.h"
+#include "internal.h"
+#include "iwl-op-mode.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 RBDs is stored in iwl->rxq->rx_free.
+ *   When the interrupt handler is called, the request is processed.
+ *   The page is either stolen - transferred to the upper layer
+ *   or reused - added immediately to the iwl->rxq->rx_free list.
+ * + When the page is stolen - the driver updates the matching queue's used
+ *   count, detaches the RBD and transfers it to the queue used list.
+ *   When there are two used RBDs - they are transferred to the allocator empty
+ *   list. Work is then scheduled for the allocator to start allocating
+ *   eight buffers.
+ *   When there are another 6 used RBDs - they are transferred to the allocator
+ *   empty list and the driver tries to claim the pre-allocated buffers and
+ *   add them to iwl->rxq->rx_free. If it fails - it continues to claim them
+ *   until ready.
+ *   When there are 8+ buffers in the free list - either from allocation or from
+ *   8 reused unstolen pages - restock is called to update the FW and indexes.
+ * + In order to make sure the allocator always has RBDs to use for allocation
+ *   the allocator has initial pool in the size of num_queues*(8-2) - the
+ *   maximum missing RBDs per allocation request (request posted with 2
+ *    empty RBDs, there is no guarantee when the other 6 RBDs are supplied).
+ *   The queues supplies the recycle of the rest of the RBDs.
+ * + A received packet is processed and handed to the kernel network stack,
+ *   detached from the iwl->rxq.  The driver 'processed' index is updated.
+ * + 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_rxq_alloc()            Allocates rx_free
+ * iwl_pcie_rx_replenish()    Replenishes rx_free list from rx_used, and calls
+ *                            iwl_pcie_rxq_restock.
+ *                            Used only during initialization.
+ * iwl_pcie_rxq_restock()     Moves available buffers from rx_free into Rx
+ *                            queue, updates firmware pointers, and updates
+ *                            the WRITE index.
+ * iwl_pcie_rx_allocator()     Background work for allocating pages.
+ *
+ * -- 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.
+ *                            Posts and claims requests to the allocator.
+ *                            Calls iwl_pcie_rxq_restock to refill any empty
+ *                            slots.
+ *
+ * RBD life-cycle:
+ *
+ * Init:
+ * rxq.pool -> rxq.rx_used -> rxq.rx_free -> rxq.queue
+ *
+ * Regular Receive interrupt:
+ * Page Stolen:
+ * rxq.queue -> rxq.rx_used -> allocator.rbd_empty ->
+ * allocator.rbd_allocated -> rxq.rx_free -> rxq.queue
+ * Page not Stolen:
+ * rxq.queue -> rxq.rx_free -> rxq.queue
+ * ...
+ *
+ */
+
+/*
+ * iwl_rxq_space - Return number of free slots available in queue.
+ */
+static int iwl_rxq_space(const struct iwl_rxq *rxq)
+{
+	/* Make sure RX_QUEUE_SIZE is a power of 2 */
+	BUILD_BUG_ON(RX_QUEUE_SIZE & (RX_QUEUE_SIZE - 1));
+
+	/*
+	 * There can be up to (RX_QUEUE_SIZE - 1) free slots, to avoid ambiguity
+	 * between empty and completely full queues.
+	 * The following is equivalent to modulo by RX_QUEUE_SIZE and is well
+	 * defined for negative dividends.
+	 */
+	return (rxq->read - rxq->write - 1) & (RX_QUEUE_SIZE - 1);
+}
+
+/*
+ * iwl_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
+ */
+static inline __le32 iwl_pcie_dma_addr2rbd_ptr(dma_addr_t dma_addr)
+{
+	return cpu_to_le32((u32)(dma_addr >> 8));
+}
+
+/*
+ * iwl_pcie_rx_stop - stops the Rx DMA
+ */
+int iwl_pcie_rx_stop(struct iwl_trans *trans)
+{
+	iwl_write_direct32(trans, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
+	return iwl_poll_direct_bit(trans, FH_MEM_RSSR_RX_STATUS_REG,
+				   FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE, 1000);
+}
+
+/*
+ * iwl_pcie_rxq_inc_wr_ptr - Update the write pointer for the RX queue
+ */
+static void iwl_pcie_rxq_inc_wr_ptr(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	u32 reg;
+
+	lockdep_assert_held(&rxq->lock);
+
+	/*
+	 * explicitly wake up the NIC if:
+	 * 1. shadow registers aren't enabled
+	 * 2. there is a chance that the NIC is asleep
+	 */
+	if (!trans->cfg->base_params->shadow_reg_enable &&
+	    test_bit(STATUS_TPOWER_PMI, &trans->status)) {
+		reg = iwl_read32(trans, CSR_UCODE_DRV_GP1);
+
+		if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
+			IWL_DEBUG_INFO(trans, "Rx queue requesting wakeup, GP1 = 0x%x\n",
+				       reg);
+			iwl_set_bit(trans, CSR_GP_CNTRL,
+				    CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
+			rxq->need_update = true;
+			return;
+		}
+	}
+
+	rxq->write_actual = round_down(rxq->write, 8);
+	iwl_write32(trans, FH_RSCSR_CHNL0_WPTR, rxq->write_actual);
+}
+
+static void iwl_pcie_rxq_check_wrptr(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+
+	spin_lock(&rxq->lock);
+
+	if (!rxq->need_update)
+		goto exit_unlock;
+
+	iwl_pcie_rxq_inc_wr_ptr(trans);
+	rxq->need_update = false;
+
+ exit_unlock:
+	spin_unlock(&rxq->lock);
+}
+
+/*
+ * iwl_pcie_rxq_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 iwl_pcie_rxq_restock(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	struct iwl_rx_mem_buffer *rxb;
+
+	/*
+	 * If the device isn't enabled - not need to try to add buffers...
+	 * This can happen when we stop the device and still have an interrupt
+	 * pending. We stop the APM before we sync the interrupts because we
+	 * have to (see comment there). On the other hand, since the APM is
+	 * stopped, we cannot access the HW (in particular not prph).
+	 * So don't try to restock if the APM has been already stopped.
+	 */
+	if (!test_bit(STATUS_DEVICE_ENABLED, &trans->status))
+		return;
+
+	spin_lock(&rxq->lock);
+	while ((iwl_rxq_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 */
+		rxb = list_first_entry(&rxq->rx_free, struct iwl_rx_mem_buffer,
+				       list);
+		list_del(&rxb->list);
+
+		/* Point to Rx buffer via next RBD in circular buffer */
+		rxq->bd[rxq->write] = iwl_pcie_dma_addr2rbd_ptr(rxb->page_dma);
+		rxq->queue[rxq->write] = rxb;
+		rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
+		rxq->free_count--;
+	}
+	spin_unlock(&rxq->lock);
+
+	/* 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(&rxq->lock);
+		iwl_pcie_rxq_inc_wr_ptr(trans);
+		spin_unlock(&rxq->lock);
+	}
+}
+
+/*
+ * iwl_pcie_rx_alloc_page - allocates and returns a page.
+ *
+ */
+static struct page *iwl_pcie_rx_alloc_page(struct iwl_trans *trans,
+					   gfp_t priority)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	struct page *page;
+	gfp_t gfp_mask = priority;
+
+	if (rxq->free_count > RX_LOW_WATERMARK)
+		gfp_mask |= __GFP_NOWARN;
+
+	if (trans_pcie->rx_page_order > 0)
+		gfp_mask |= __GFP_COMP;
+
+	/* Alloc a new receive buffer */
+	page = alloc_pages(gfp_mask, trans_pcie->rx_page_order);
+	if (!page) {
+		if (net_ratelimit())
+			IWL_DEBUG_INFO(trans, "alloc_pages failed, order: %d\n",
+				       trans_pcie->rx_page_order);
+		/* Issue an error if the hardware has consumed more than half
+		 * of its free buffer list and we don't have enough
+		 * pre-allocated buffers.
+`		 */
+		if (rxq->free_count <= RX_LOW_WATERMARK &&
+		    iwl_rxq_space(rxq) > (RX_QUEUE_SIZE / 2) &&
+		    net_ratelimit())
+			IWL_CRIT(trans,
+				 "Failed to alloc_pages with GFP_KERNEL. Only %u free buffers remaining.\n",
+				 rxq->free_count);
+		return NULL;
+	}
+	return page;
+}
+
+/*
+ * iwl_pcie_rxq_alloc_rbs - allocate a page for each used RBD
+ *
+ * A used RBD is an Rx buffer that has been given to the stack. To use it again
+ * a page must be allocated and the RBD must point to the page. This function
+ * doesn't change the HW pointer but handles the list of pages that is used by
+ * iwl_pcie_rxq_restock. The latter function will update the HW to use the newly
+ * allocated buffers.
+ */
+static void iwl_pcie_rxq_alloc_rbs(struct iwl_trans *trans, gfp_t priority)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	struct iwl_rx_mem_buffer *rxb;
+	struct page *page;
+
+	while (1) {
+		spin_lock(&rxq->lock);
+		if (list_empty(&rxq->rx_used)) {
+			spin_unlock(&rxq->lock);
+			return;
+		}
+		spin_unlock(&rxq->lock);
+
+		/* Alloc a new receive buffer */
+		page = iwl_pcie_rx_alloc_page(trans, priority);
+		if (!page)
+			return;
+
+		spin_lock(&rxq->lock);
+
+		if (list_empty(&rxq->rx_used)) {
+			spin_unlock(&rxq->lock);
+			__free_pages(page, trans_pcie->rx_page_order);
+			return;
+		}
+		rxb = list_first_entry(&rxq->rx_used, struct iwl_rx_mem_buffer,
+				       list);
+		list_del(&rxb->list);
+		spin_unlock(&rxq->lock);
+
+		BUG_ON(rxb->page);
+		rxb->page = page;
+		/* Get physical address of the RB */
+		rxb->page_dma =
+			dma_map_page(trans->dev, page, 0,
+				     PAGE_SIZE << trans_pcie->rx_page_order,
+				     DMA_FROM_DEVICE);
+		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
+			rxb->page = NULL;
+			spin_lock(&rxq->lock);
+			list_add(&rxb->list, &rxq->rx_used);
+			spin_unlock(&rxq->lock);
+			__free_pages(page, trans_pcie->rx_page_order);
+			return;
+		}
+		/* 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(&rxq->lock);
+
+		list_add_tail(&rxb->list, &rxq->rx_free);
+		rxq->free_count++;
+
+		spin_unlock(&rxq->lock);
+	}
+}
+
+static void iwl_pcie_rxq_free_rbs(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	int i;
+
+	lockdep_assert_held(&rxq->lock);
+
+	for (i = 0; i < RX_QUEUE_SIZE; i++) {
+		if (!rxq->pool[i].page)
+			continue;
+		dma_unmap_page(trans->dev, rxq->pool[i].page_dma,
+			       PAGE_SIZE << trans_pcie->rx_page_order,
+			       DMA_FROM_DEVICE);
+		__free_pages(rxq->pool[i].page, trans_pcie->rx_page_order);
+		rxq->pool[i].page = NULL;
+	}
+}
+
+/*
+ * iwl_pcie_rx_replenish - Move all used buffers from rx_used to rx_free
+ *
+ * When moving to rx_free an page is allocated for the slot.
+ *
+ * Also restock the Rx queue via iwl_pcie_rxq_restock.
+ * This is called only during initialization
+ */
+static void iwl_pcie_rx_replenish(struct iwl_trans *trans)
+{
+	iwl_pcie_rxq_alloc_rbs(trans, GFP_KERNEL);
+
+	iwl_pcie_rxq_restock(trans);
+}
+
+/*
+ * iwl_pcie_rx_allocator - Allocates pages in the background for RX queues
+ *
+ * Allocates for each received request 8 pages
+ * Called as a scheduled work item.
+ */
+static void iwl_pcie_rx_allocator(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+	struct list_head local_empty;
+	int pending = atomic_xchg(&rba->req_pending, 0);
+
+	IWL_DEBUG_RX(trans, "Pending allocation requests = %d\n", pending);
+
+	/* If we were scheduled - there is at least one request */
+	spin_lock(&rba->lock);
+	/* swap out the rba->rbd_empty to a local list */
+	list_replace_init(&rba->rbd_empty, &local_empty);
+	spin_unlock(&rba->lock);
+
+	while (pending) {
+		int i;
+		struct list_head local_allocated;
+
+		INIT_LIST_HEAD(&local_allocated);
+
+		for (i = 0; i < RX_CLAIM_REQ_ALLOC;) {
+			struct iwl_rx_mem_buffer *rxb;
+			struct page *page;
+
+			/* List should never be empty - each reused RBD is
+			 * returned to the list, and initial pool covers any
+			 * possible gap between the time the page is allocated
+			 * to the time the RBD is added.
+			 */
+			BUG_ON(list_empty(&local_empty));
+			/* Get the first rxb from the rbd list */
+			rxb = list_first_entry(&local_empty,
+					       struct iwl_rx_mem_buffer, list);
+			BUG_ON(rxb->page);
+
+			/* Alloc a new receive buffer */
+			page = iwl_pcie_rx_alloc_page(trans, GFP_KERNEL);
+			if (!page)
+				continue;
+			rxb->page = page;
+
+			/* Get physical address of the RB */
+			rxb->page_dma = dma_map_page(trans->dev, page, 0,
+					PAGE_SIZE << trans_pcie->rx_page_order,
+					DMA_FROM_DEVICE);
+			if (dma_mapping_error(trans->dev, rxb->page_dma)) {
+				rxb->page = NULL;
+				__free_pages(page, trans_pcie->rx_page_order);
+				continue;
+			}
+			/* 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));
+
+			/* move the allocated entry to the out list */
+			list_move(&rxb->list, &local_allocated);
+			i++;
+		}
+
+		pending--;
+		if (!pending) {
+			pending = atomic_xchg(&rba->req_pending, 0);
+			IWL_DEBUG_RX(trans,
+				     "Pending allocation requests = %d\n",
+				     pending);
+		}
+
+		spin_lock(&rba->lock);
+		/* add the allocated rbds to the allocator allocated list */
+		list_splice_tail(&local_allocated, &rba->rbd_allocated);
+		/* get more empty RBDs for current pending requests */
+		list_splice_tail_init(&rba->rbd_empty, &local_empty);
+		spin_unlock(&rba->lock);
+
+		atomic_inc(&rba->req_ready);
+	}
+
+	spin_lock(&rba->lock);
+	/* return unused rbds to the allocator empty list */
+	list_splice_tail(&local_empty, &rba->rbd_empty);
+	spin_unlock(&rba->lock);
+}
+
+/*
+ * iwl_pcie_rx_allocator_get - Returns the pre-allocated pages
+.*
+.* Called by queue when the queue posted allocation request and
+ * has freed 8 RBDs in order to restock itself.
+ */
+static int iwl_pcie_rx_allocator_get(struct iwl_trans *trans,
+				     struct iwl_rx_mem_buffer
+				     *out[RX_CLAIM_REQ_ALLOC])
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+	int i;
+
+	/*
+	 * atomic_dec_if_positive returns req_ready - 1 for any scenario.
+	 * If req_ready is 0 atomic_dec_if_positive will return -1 and this
+	 * function will return -ENOMEM, as there are no ready requests.
+	 * atomic_dec_if_positive will perofrm the *actual* decrement only if
+	 * req_ready > 0, i.e. - there are ready requests and the function
+	 * hands one request to the caller.
+	 */
+	if (atomic_dec_if_positive(&rba->req_ready) < 0)
+		return -ENOMEM;
+
+	spin_lock(&rba->lock);
+	for (i = 0; i < RX_CLAIM_REQ_ALLOC; i++) {
+		/* Get next free Rx buffer, remove it from free list */
+		out[i] = list_first_entry(&rba->rbd_allocated,
+			       struct iwl_rx_mem_buffer, list);
+		list_del(&out[i]->list);
+	}
+	spin_unlock(&rba->lock);
+
+	return 0;
+}
+
+static void iwl_pcie_rx_allocator_work(struct work_struct *data)
+{
+	struct iwl_rb_allocator *rba_p =
+		container_of(data, struct iwl_rb_allocator, rx_alloc);
+	struct iwl_trans_pcie *trans_pcie =
+		container_of(rba_p, struct iwl_trans_pcie, rba);
+
+	iwl_pcie_rx_allocator(trans_pcie->trans);
+}
+
+static int iwl_pcie_rx_alloc(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+	struct device *dev = trans->dev;
+
+	memset(&trans_pcie->rxq, 0, sizeof(trans_pcie->rxq));
+
+	spin_lock_init(&rxq->lock);
+	spin_lock_init(&rba->lock);
+
+	if (WARN_ON(rxq->bd || rxq->rb_stts))
+		return -EINVAL;
+
+	/* Allocate the circular buffer of Read Buffer Descriptors (RBDs) */
+	rxq->bd = dma_zalloc_coherent(dev, sizeof(__le32) * RX_QUEUE_SIZE,
+				      &rxq->bd_dma, GFP_KERNEL);
+	if (!rxq->bd)
+		goto err_bd;
+
+	/*Allocate the driver's pointer to receive buffer status */
+	rxq->rb_stts = dma_zalloc_coherent(dev, sizeof(*rxq->rb_stts),
+					   &rxq->rb_stts_dma, GFP_KERNEL);
+	if (!rxq->rb_stts)
+		goto err_rb_stts;
+
+	return 0;
+
+err_rb_stts:
+	dma_free_coherent(dev, sizeof(__le32) * RX_QUEUE_SIZE,
+			  rxq->bd, rxq->bd_dma);
+	rxq->bd_dma = 0;
+	rxq->bd = NULL;
+err_bd:
+	return -ENOMEM;
+}
+
+static void iwl_pcie_rx_hw_init(struct iwl_trans *trans, struct iwl_rxq *rxq)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	u32 rb_size;
+	const u32 rfdnlog = RX_QUEUE_SIZE_LOG; /* 256 RBDs */
+
+	if (trans_pcie->rx_buf_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(trans, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
+	/* reset and flush pointers */
+	iwl_write_direct32(trans, FH_MEM_RCSR_CHNL0_RBDCB_WPTR, 0);
+	iwl_write_direct32(trans, FH_MEM_RCSR_CHNL0_FLUSH_RB_REQ, 0);
+	iwl_write_direct32(trans, FH_RSCSR_CHNL0_RDPTR, 0);
+
+	/* Reset driver's Rx queue write index */
+	iwl_write_direct32(trans, FH_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);
+
+	/* Tell device where to find RBD circular buffer in DRAM */
+	iwl_write_direct32(trans, FH_RSCSR_CHNL0_RBDCB_BASE_REG,
+			   (u32)(rxq->bd_dma >> 8));
+
+	/* Tell device where in DRAM to update its Rx status */
+	iwl_write_direct32(trans, FH_RSCSR_CHNL0_STTS_WPTR_REG,
+			   rxq->rb_stts_dma >> 4);
+
+	/* Enable Rx DMA
+	 * FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY is set because 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(trans, 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|
+			   (RX_RB_TIMEOUT << FH_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS)|
+			   (rfdnlog << FH_RCSR_RX_CONFIG_RBDCB_SIZE_POS));
+
+	/* Set interrupt coalescing timer to default (2048 usecs) */
+	iwl_write8(trans, CSR_INT_COALESCING, IWL_HOST_INT_TIMEOUT_DEF);
+
+	/* W/A for interrupt coalescing bug in 7260 and 3160 */
+	if (trans->cfg->host_interrupt_operation_mode)
+		iwl_set_bit(trans, CSR_INT_COALESCING, IWL_HOST_INT_OPER_MODE);
+}
+
+static void iwl_pcie_rx_init_rxb_lists(struct iwl_rxq *rxq)
+{
+	int i;
+
+	lockdep_assert_held(&rxq->lock);
+
+	INIT_LIST_HEAD(&rxq->rx_free);
+	INIT_LIST_HEAD(&rxq->rx_used);
+	rxq->free_count = 0;
+	rxq->used_count = 0;
+
+	for (i = 0; i < RX_QUEUE_SIZE; i++)
+		list_add(&rxq->pool[i].list, &rxq->rx_used);
+}
+
+static void iwl_pcie_rx_init_rba(struct iwl_rb_allocator *rba)
+{
+	int i;
+
+	lockdep_assert_held(&rba->lock);
+
+	INIT_LIST_HEAD(&rba->rbd_allocated);
+	INIT_LIST_HEAD(&rba->rbd_empty);
+
+	for (i = 0; i < RX_POOL_SIZE; i++)
+		list_add(&rba->pool[i].list, &rba->rbd_empty);
+}
+
+static void iwl_pcie_rx_free_rba(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+	int i;
+
+	lockdep_assert_held(&rba->lock);
+
+	for (i = 0; i < RX_POOL_SIZE; i++) {
+		if (!rba->pool[i].page)
+			continue;
+		dma_unmap_page(trans->dev, rba->pool[i].page_dma,
+			       PAGE_SIZE << trans_pcie->rx_page_order,
+			       DMA_FROM_DEVICE);
+		__free_pages(rba->pool[i].page, trans_pcie->rx_page_order);
+		rba->pool[i].page = NULL;
+	}
+}
+
+int iwl_pcie_rx_init(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+	int i, err;
+
+	if (!rxq->bd) {
+		err = iwl_pcie_rx_alloc(trans);
+		if (err)
+			return err;
+	}
+	if (!rba->alloc_wq)
+		rba->alloc_wq = alloc_workqueue("rb_allocator",
+						WQ_HIGHPRI | WQ_UNBOUND, 1);
+	INIT_WORK(&rba->rx_alloc, iwl_pcie_rx_allocator_work);
+
+	spin_lock(&rba->lock);
+	atomic_set(&rba->req_pending, 0);
+	atomic_set(&rba->req_ready, 0);
+	/* free all first - we might be reconfigured for a different size */
+	iwl_pcie_rx_free_rba(trans);
+	iwl_pcie_rx_init_rba(rba);
+	spin_unlock(&rba->lock);
+
+	spin_lock(&rxq->lock);
+
+	/* free all first - we might be reconfigured for a different size */
+	iwl_pcie_rxq_free_rbs(trans);
+	iwl_pcie_rx_init_rxb_lists(rxq);
+
+	for (i = 0; i < RX_QUEUE_SIZE; i++)
+		rxq->queue[i] = NULL;
+
+	/* 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;
+	memset(rxq->rb_stts, 0, sizeof(*rxq->rb_stts));
+	spin_unlock(&rxq->lock);
+
+	iwl_pcie_rx_replenish(trans);
+
+	iwl_pcie_rx_hw_init(trans, rxq);
+
+	spin_lock(&rxq->lock);
+	iwl_pcie_rxq_inc_wr_ptr(trans);
+	spin_unlock(&rxq->lock);
+
+	return 0;
+}
+
+void iwl_pcie_rx_free(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rxq *rxq = &trans_pcie->rxq;
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+
+	/*if rxq->bd is NULL, it means that nothing has been allocated,
+	 * exit now */
+	if (!rxq->bd) {
+		IWL_DEBUG_INFO(trans, "Free NULL rx context\n");
+		return;
+	}
+
+	cancel_work_sync(&rba->rx_alloc);
+	if (rba->alloc_wq) {
+		destroy_workqueue(rba->alloc_wq);
+		rba->alloc_wq = NULL;
+	}
+
+	spin_lock(&rba->lock);
+	iwl_pcie_rx_free_rba(trans);
+	spin_unlock(&rba->lock);
+
+	spin_lock(&rxq->lock);
+	iwl_pcie_rxq_free_rbs(trans);
+	spin_unlock(&rxq->lock);
+
+	dma_free_coherent(trans->dev, sizeof(__le32) * RX_QUEUE_SIZE,
+			  rxq->bd, rxq->bd_dma);
+	rxq->bd_dma = 0;
+	rxq->bd = NULL;
+
+	if (rxq->rb_stts)
+		dma_free_coherent(trans->dev,
+				  sizeof(struct iwl_rb_status),
+				  rxq->rb_stts, rxq->rb_stts_dma);
+	else
+		IWL_DEBUG_INFO(trans, "Free rxq->rb_stts which is NULL\n");
+	rxq->rb_stts_dma = 0;
+	rxq->rb_stts = NULL;
+}
+
+/*
+ * iwl_pcie_rx_reuse_rbd - Recycle used RBDs
+ *
+ * Called when a RBD can be reused. The RBD is transferred to the allocator.
+ * When there are 2 empty RBDs - a request for allocation is posted
+ */
+static void iwl_pcie_rx_reuse_rbd(struct iwl_trans *trans,
+				  struct iwl_rx_mem_buffer *rxb,
+				  struct iwl_rxq *rxq, bool emergency)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_rb_allocator *rba = &trans_pcie->rba;
+
+	/* Move the RBD to the used list, will be moved to allocator in batches
+	 * before claiming or posting a request*/
+	list_add_tail(&rxb->list, &rxq->rx_used);
+
+	if (unlikely(emergency))
+		return;
+
+	/* Count the allocator owned RBDs */
+	rxq->used_count++;
+
+	/* If we have RX_POST_REQ_ALLOC new released rx buffers -
+	 * issue a request for allocator. Modulo RX_CLAIM_REQ_ALLOC is
+	 * used for the case we failed to claim RX_CLAIM_REQ_ALLOC,
+	 * after but we still need to post another request.
+	 */
+	if ((rxq->used_count % RX_CLAIM_REQ_ALLOC) == RX_POST_REQ_ALLOC) {
+		/* Move the 2 RBDs to the allocator ownership.
+		 Allocator has another 6 from pool for the request completion*/
+		spin_lock(&rba->lock);
+		list_splice_tail_init(&rxq->rx_used, &rba->rbd_empty);
+		spin_unlock(&rba->lock);
+
+		atomic_inc(&rba->req_pending);
+		queue_work(rba->alloc_wq, &rba->rx_alloc);
+	}
+}
+
+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,
+			     get_cmd_string(trans_pcie, pkt->hdr.cmd),
+			     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 (%p)\n",
+			     r, i, rxb);
+		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;
+}
+
+/* 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))
+
+/* 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.
+ */
+static u32 iwl_pcie_int_cause_ict(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	u32 inta;
+	u32 val = 0;
+	u32 read;
+
+	trace_iwlwifi_dev_irq(trans->dev);
+
+	/* 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)
+		return 0;
+
+	/*
+	 * 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 =
+			((trans_pcie->ict_index + 1) & (ICT_COUNT - 1));
+
+		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);
+	return inta;
+}
+
+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;
+
+	lock_map_acquire(&trans->sync_cmd_lockdep_map);
+
+	spin_lock(&trans_pcie->irq_lock);
+
+	/* dram interrupt table not set yet,
+	 * use legacy interrupt.
+	 */
+	if (likely(trans_pcie->use_ict))
+		inta = iwl_pcie_int_cause_ict(trans);
+	else
+		inta = iwl_pcie_int_cause_non_ict(trans);
+
+	if (iwl_have_debug_level(IWL_DL_ISR)) {
+		IWL_DEBUG_ISR(trans,
+			      "ISR inta 0x%08x, enabled 0x%08x(sw), enabled(hw) 0x%08x, fh 0x%08x\n",
+			      inta, trans_pcie->inta_mask,
+			      iwl_read32(trans, CSR_INT_MASK),
+			      iwl_read32(trans, CSR_FH_INT_STATUS));
+		if (inta & (~trans_pcie->inta_mask))
+			IWL_DEBUG_ISR(trans,
+				      "We got a masked interrupt (0x%08x)\n",
+				      inta & (~trans_pcie->inta_mask));
+	}
+
+	inta &= trans_pcie->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 (unlikely(!inta)) {
+		IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n");
+		/*
+		 * Re-enable interrupts here since we don't
+		 * have anything to service
+		 */
+		if (test_bit(STATUS_INT_ENABLED, &trans->status))
+			iwl_enable_interrupts(trans);
+		spin_unlock(&trans_pcie->irq_lock);
+		lock_map_release(&trans->sync_cmd_lockdep_map);
+		return IRQ_NONE;
+	}
+
+	if (unlikely(inta == 0xFFFFFFFF || (inta & 0xFFFFFFF0) == 0xa5a5a5a0)) {
+		/*
+		 * Hardware disappeared. It might have
+		 * already raised an interrupt.
+		 */
+		IWL_WARN(trans, "HARDWARE GONE?? INTA == 0x%08x\n", inta);
+		spin_unlock(&trans_pcie->irq_lock);
+		goto out;
+	}
+
+	/* 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, inta | ~trans_pcie->inta_mask);
+
+	if (iwl_have_debug_level(IWL_DL_ISR))
+		IWL_DEBUG_ISR(trans, "inta 0x%08x, enabled 0x%08x\n",
+			      inta, iwl_read32(trans, CSR_INT_MASK));
+
+	spin_unlock(&trans_pcie->irq_lock);
+
+	/* 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;
+	}
+
+	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++;
+		}
+	}
+
+	/* 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++;
+
+		mutex_lock(&trans_pcie->mutex);
+		iwl_trans_pcie_rf_kill(trans, hw_rfkill);
+		mutex_unlock(&trans_pcie->mutex);
+		if (hw_rfkill) {
+			set_bit(STATUS_RFKILL, &trans->status);
+			if (test_and_clear_bit(STATUS_SYNC_HCMD_ACTIVE,
+					       &trans->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->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_check_wrptr(trans);
+		iwl_pcie_txq_check_wrptrs(trans);
+
+		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);
+
+		/*
+		 * 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++;
+
+		local_bh_disable();
+		iwl_pcie_rx_handle(trans);
+		local_bh_enable();
+	}
+
+	/* 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->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
+ *
+ ******************************************************************************/
+
+/* 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_zalloc_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 ict vir addr %p\n",
+		      (unsigned long long)trans_pcie->ict_tbl_dma,
+		      trans_pcie->ict_tbl);
+
+	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;
+
+	if (!trans_pcie->ict_tbl)
+		return;
+
+	spin_lock(&trans_pcie->irq_lock);
+	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 |
+	       CSR_DRAM_INIT_TBL_WRAP_CHECK |
+	       CSR_DRAM_INIT_TBL_WRITE_POINTER;
+
+	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(&trans_pcie->irq_lock);
+}
+
+/* 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);
+
+	spin_lock(&trans_pcie->irq_lock);
+	trans_pcie->use_ict = false;
+	spin_unlock(&trans_pcie->irq_lock);
+}
+
+irqreturn_t iwl_pcie_isr(int irq, void *data)
+{
+	struct iwl_trans *trans = data;
+
+	if (!trans)
+		return IRQ_NONE;
+
+	/* 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.
+	 */
+	iwl_write32(trans, CSR_INT_MASK, 0x00000000);
+
+	return IRQ_WAKE_THREAD;
+}