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authorJohannes Berg <johannes.berg@intel.com>2012-05-16 19:13:54 +0200
committerJohannes Berg <johannes.berg@intel.com>2012-06-06 13:09:30 +0200
commit6468a01a7181f3572a3e686910016f89ee71ff45 (patch)
treef0c3749d16bb34d8e033281d981779517aab06d3 /drivers/net/wireless/iwlwifi/pcie/rx.c
parent76a3aa89937cf0b9a560e4c778e54e993018da60 (diff)
iwlwifi: move PCIe into subdirectory
Structure the code a bit more and move all PCIe code including the hardware configuration files into a PCIe specific subdirectory. Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'drivers/net/wireless/iwlwifi/pcie/rx.c')
-rw-r--r--drivers/net/wireless/iwlwifi/pcie/rx.c1058
1 files changed, 1058 insertions, 0 deletions
diff --git a/drivers/net/wireless/iwlwifi/pcie/rx.c b/drivers/net/wireless/iwlwifi/pcie/rx.c
new file mode 100644
index 00000000000..d6860c070c1
--- /dev/null
+++ b/drivers/net/wireless/iwlwifi/pcie/rx.c
@@ -0,0 +1,1058 @@
+/******************************************************************************
+ *
+ * Copyright(c) 2003 - 2012 Intel Corporation. All rights reserved.
+ *
+ * Portions of this file are derived from the ipw3945 project, as well
+ * as portions of the ieee80211 subsystem header files.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
+ *
+ * The full GNU General Public License is included in this distribution in the
+ * file called LICENSE.
+ *
+ * Contact Information:
+ * Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ *****************************************************************************/
+#include <linux/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"
+
+#ifdef CONFIG_IWLWIFI_IDI
+#include "iwl-amfh.h"
+#endif
+
+/******************************************************************************
+ *
+ * RX path functions
+ *
+ ******************************************************************************/
+
+/*
+ * Rx theory of operation
+ *
+ * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
+ * each of which point to Receive Buffers to be filled by the NIC. These get
+ * used not only for Rx frames, but for any command response or notification
+ * from the NIC. The driver and NIC manage the Rx buffers by means
+ * of indexes into the circular buffer.
+ *
+ * Rx Queue Indexes
+ * The host/firmware share two index registers for managing the Rx buffers.
+ *
+ * The READ index maps to the first position that the firmware may be writing
+ * to -- the driver can read up to (but not including) this position and get
+ * good data.
+ * The READ index is managed by the firmware once the card is enabled.
+ *
+ * The WRITE index maps to the last position the driver has read from -- the
+ * position preceding WRITE is the last slot the firmware can place a packet.
+ *
+ * The queue is empty (no good data) if WRITE = READ - 1, and is full if
+ * WRITE = READ.
+ *
+ * During initialization, the host sets up the READ queue position to the first
+ * INDEX position, and WRITE to the last (READ - 1 wrapped)
+ *
+ * When the firmware places a packet in a buffer, it will advance the READ index
+ * and fire the RX interrupt. The driver can then query the READ index and
+ * process as many packets as possible, moving the WRITE index forward as it
+ * resets the Rx queue buffers with new memory.
+ *
+ * The management in the driver is as follows:
+ * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When
+ * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
+ * to replenish the iwl->rxq->rx_free.
+ * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the
+ * iwl->rxq is replenished and the READ INDEX is updated (updating the
+ * 'processed' and 'read' driver indexes as well)
+ * + A received packet is processed and handed to the kernel network stack,
+ * detached from the iwl->rxq. The driver 'processed' index is updated.
+ * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
+ * list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
+ * INDEX is not incremented and iwl->status(RX_STALLED) is set. If there
+ * were enough free buffers and RX_STALLED is set it is cleared.
+ *
+ *
+ * Driver sequence:
+ *
+ * iwl_rx_queue_alloc() Allocates rx_free
+ * iwl_rx_replenish() Replenishes rx_free list from rx_used, and calls
+ * iwl_rx_queue_restock
+ * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx
+ * queue, updates firmware pointers, and updates
+ * the WRITE index. If insufficient rx_free buffers
+ * are available, schedules iwl_rx_replenish
+ *
+ * -- enable interrupts --
+ * ISR - iwl_rx() Detach iwl_rx_mem_buffers from pool up to the
+ * READ INDEX, detaching the SKB from the pool.
+ * Moves the packet buffer from queue to rx_used.
+ * Calls iwl_rx_queue_restock to refill any empty
+ * slots.
+ * ...
+ *
+ */
+
+/**
+ * iwl_rx_queue_space - Return number of free slots available in queue.
+ */
+static int iwl_rx_queue_space(const struct iwl_rx_queue *q)
+{
+ int s = q->read - q->write;
+ if (s <= 0)
+ s += RX_QUEUE_SIZE;
+ /* keep some buffer to not confuse full and empty queue */
+ s -= 2;
+ if (s < 0)
+ s = 0;
+ return s;
+}
+
+/**
+ * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue
+ */
+void iwl_rx_queue_update_write_ptr(struct iwl_trans *trans,
+ struct iwl_rx_queue *q)
+{
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ if (q->need_update == 0)
+ goto exit_unlock;
+
+ if (trans->cfg->base_params->shadow_reg_enable) {
+ /* shadow register enabled */
+ /* Device expects a multiple of 8 */
+ q->write_actual = (q->write & ~0x7);
+ iwl_write32(trans, FH_RSCSR_CHNL0_WPTR, q->write_actual);
+ } else {
+ struct iwl_trans_pcie *trans_pcie =
+ IWL_TRANS_GET_PCIE_TRANS(trans);
+
+ /* If power-saving is in use, make sure device is awake */
+ if (test_bit(STATUS_TPOWER_PMI, &trans_pcie->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);
+ goto exit_unlock;
+ }
+
+ q->write_actual = (q->write & ~0x7);
+ iwl_write_direct32(trans, FH_RSCSR_CHNL0_WPTR,
+ q->write_actual);
+
+ /* Else device is assumed to be awake */
+ } else {
+ /* Device expects a multiple of 8 */
+ q->write_actual = (q->write & ~0x7);
+ iwl_write_direct32(trans, FH_RSCSR_CHNL0_WPTR,
+ q->write_actual);
+ }
+ }
+ q->need_update = 0;
+
+ exit_unlock:
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+
+/**
+ * iwlagn_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
+ */
+static inline __le32 iwlagn_dma_addr2rbd_ptr(dma_addr_t dma_addr)
+{
+ return cpu_to_le32((u32)(dma_addr >> 8));
+}
+
+/**
+ * iwlagn_rx_queue_restock - refill RX queue from pre-allocated pool
+ *
+ * If there are slots in the RX queue that need to be restocked,
+ * and we have free pre-allocated buffers, fill the ranks as much
+ * as we can, pulling from rx_free.
+ *
+ * This moves the 'write' index forward to catch up with 'processed', and
+ * also updates the memory address in the firmware to reference the new
+ * target buffer.
+ */
+static void iwlagn_rx_queue_restock(struct iwl_trans *trans)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ struct iwl_rx_queue *rxq = &trans_pcie->rxq;
+ struct list_head *element;
+ struct iwl_rx_mem_buffer *rxb;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rxq->lock, flags);
+ while ((iwl_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
+ /* The overwritten rxb must be a used one */
+ rxb = rxq->queue[rxq->write];
+ BUG_ON(rxb && rxb->page);
+
+ /* Get next free Rx buffer, remove from free list */
+ element = rxq->rx_free.next;
+ rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
+ list_del(element);
+
+ /* Point to Rx buffer via next RBD in circular buffer */
+ rxq->bd[rxq->write] = iwlagn_dma_addr2rbd_ptr(rxb->page_dma);
+ rxq->queue[rxq->write] = rxb;
+ rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
+ rxq->free_count--;
+ }
+ spin_unlock_irqrestore(&rxq->lock, flags);
+ /* If the pre-allocated buffer pool is dropping low, schedule to
+ * refill it */
+ if (rxq->free_count <= RX_LOW_WATERMARK)
+ schedule_work(&trans_pcie->rx_replenish);
+
+
+ /* If we've added more space for the firmware to place data, tell it.
+ * Increment device's write pointer in multiples of 8. */
+ if (rxq->write_actual != (rxq->write & ~0x7)) {
+ spin_lock_irqsave(&rxq->lock, flags);
+ rxq->need_update = 1;
+ spin_unlock_irqrestore(&rxq->lock, flags);
+ iwl_rx_queue_update_write_ptr(trans, rxq);
+ }
+}
+
+/**
+ * iwlagn_rx_replenish - Move all used packet from rx_used to rx_free
+ *
+ * When moving to rx_free an SKB is allocated for the slot.
+ *
+ * Also restock the Rx queue via iwl_rx_queue_restock.
+ * This is called as a scheduled work item (except for during initialization)
+ */
+static void iwlagn_rx_allocate(struct iwl_trans *trans, gfp_t priority)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ struct iwl_rx_queue *rxq = &trans_pcie->rxq;
+ struct list_head *element;
+ struct iwl_rx_mem_buffer *rxb;
+ struct page *page;
+ unsigned long flags;
+ gfp_t gfp_mask = priority;
+
+ while (1) {
+ spin_lock_irqsave(&rxq->lock, flags);
+ if (list_empty(&rxq->rx_used)) {
+ spin_unlock_irqrestore(&rxq->lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&rxq->lock, flags);
+
+ if (rxq->free_count > RX_LOW_WATERMARK)
+ gfp_mask |= __GFP_NOWARN;
+
+ if (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);
+
+ if ((rxq->free_count <= RX_LOW_WATERMARK) &&
+ net_ratelimit())
+ IWL_CRIT(trans, "Failed to alloc_pages with %s."
+ "Only %u free buffers remaining.\n",
+ priority == GFP_ATOMIC ?
+ "GFP_ATOMIC" : "GFP_KERNEL",
+ rxq->free_count);
+ /* We don't reschedule replenish work here -- we will
+ * call the restock method and if it still needs
+ * more buffers it will schedule replenish */
+ return;
+ }
+
+ spin_lock_irqsave(&rxq->lock, flags);
+
+ if (list_empty(&rxq->rx_used)) {
+ spin_unlock_irqrestore(&rxq->lock, flags);
+ __free_pages(page, trans_pcie->rx_page_order);
+ return;
+ }
+ element = rxq->rx_used.next;
+ rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
+ list_del(element);
+
+ spin_unlock_irqrestore(&rxq->lock, flags);
+
+ BUG_ON(rxb->page);
+ rxb->page = page;
+ /* Get physical address of the RB */
+ rxb->page_dma =
+ dma_map_page(trans->dev, page, 0,
+ PAGE_SIZE << trans_pcie->rx_page_order,
+ DMA_FROM_DEVICE);
+ /* dma address must be no more than 36 bits */
+ BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
+ /* and also 256 byte aligned! */
+ BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));
+
+ spin_lock_irqsave(&rxq->lock, flags);
+
+ list_add_tail(&rxb->list, &rxq->rx_free);
+ rxq->free_count++;
+
+ spin_unlock_irqrestore(&rxq->lock, flags);
+ }
+}
+
+void iwlagn_rx_replenish(struct iwl_trans *trans)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ unsigned long flags;
+
+ iwlagn_rx_allocate(trans, GFP_KERNEL);
+
+ spin_lock_irqsave(&trans_pcie->irq_lock, flags);
+ iwlagn_rx_queue_restock(trans);
+ spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
+}
+
+static void iwlagn_rx_replenish_now(struct iwl_trans *trans)
+{
+ iwlagn_rx_allocate(trans, GFP_ATOMIC);
+
+ iwlagn_rx_queue_restock(trans);
+}
+
+void iwl_bg_rx_replenish(struct work_struct *data)
+{
+ struct iwl_trans_pcie *trans_pcie =
+ container_of(data, struct iwl_trans_pcie, rx_replenish);
+
+ iwlagn_rx_replenish(trans_pcie->trans);
+}
+
+static void iwl_rx_handle_rxbuf(struct iwl_trans *trans,
+ struct iwl_rx_mem_buffer *rxb)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ struct iwl_rx_queue *rxq = &trans_pcie->rxq;
+ struct iwl_tx_queue *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,
+ ._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,
+ trans_pcie_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, 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);
+
+ /*
+ * 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_tx_cmd_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);
+ 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_rx_handle - Main entry function for receiving responses from uCode
+ *
+ * Uses the priv->rx_handlers callback function array to invoke
+ * the appropriate handlers, including command responses,
+ * frame-received notifications, and other notifications.
+ */
+static void iwl_rx_handle(struct iwl_trans *trans)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ struct iwl_rx_queue *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(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_rx_handle_rxbuf(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;
+ iwlagn_rx_replenish_now(trans);
+ count = 0;
+ }
+ }
+ }
+
+ /* Backtrack one entry */
+ rxq->read = i;
+ if (fill_rx)
+ iwlagn_rx_replenish_now(trans);
+ else
+ iwlagn_rx_queue_restock(trans);
+}
+
+/**
+ * iwl_irq_handle_error - called for HW or SW error interrupt from card
+ */
+static void iwl_irq_handle_error(struct iwl_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))) {
+ struct iwl_trans_pcie *trans_pcie =
+ IWL_TRANS_GET_PCIE_TRANS(trans);
+
+ clear_bit(STATUS_HCMD_ACTIVE, &trans_pcie->status);
+ iwl_op_mode_wimax_active(trans->op_mode);
+ wake_up(&trans->wait_command_queue);
+ return;
+ }
+
+ iwl_dump_csr(trans);
+ iwl_dump_fh(trans, NULL, false);
+
+ iwl_op_mode_nic_error(trans->op_mode);
+}
+
+/* tasklet for iwlagn interrupt */
+void iwl_irq_tasklet(struct iwl_trans *trans)
+{
+ 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
+
+ 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_irq_handle_error(trans);
+
+ handled |= CSR_INT_BIT_HW_ERR;
+
+ return;
+ }
+
+#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);
+
+ 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_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_rx_queue_update_write_ptr(trans, &trans_pcie->rxq);
+ for (i = 0; i < trans->cfg->base_params->num_of_queues; i++)
+ iwl_txq_update_write_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);
+#ifdef CONFIG_IWLWIFI_IDI
+ iwl_amfh_rx_handler();
+#else
+ iwl_rx_handle(trans);
+#endif
+ /*
+ * 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);
+}
+
+/******************************************************************************
+ *
+ * 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_free_isr_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_alloc_isr_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_free_isr_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_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_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);
+}
+
+static irqreturn_t iwl_isr(int irq, void *data)
+{
+ struct iwl_trans *trans = data;
+ struct iwl_trans_pcie *trans_pcie;
+ u32 inta, inta_mask;
+ unsigned long flags;
+#ifdef CONFIG_IWLWIFI_DEBUG
+ u32 inta_fh;
+#endif
+ if (!trans)
+ return IRQ_NONE;
+
+ trace_iwlwifi_dev_irq(trans->dev);
+
+ trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+ spin_lock_irqsave(&trans_pcie->irq_lock, flags);
+
+ /* 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); /* just for debug */
+ iwl_write32(trans, CSR_INT_MASK, 0x00000000);
+
+ /* Discover which interrupts are active/pending */
+ inta = iwl_read32(trans, CSR_INT);
+
+ /* 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);
+ goto unplugged;
+ }
+
+#ifdef CONFIG_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;
+ /* iwl_irq_tasklet() will service interrupts and re-enable them */
+ if (likely(inta))
+ tasklet_schedule(&trans_pcie->irq_tasklet);
+ else if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
+ !trans_pcie->inta)
+ iwl_enable_interrupts(trans);
+
+ unplugged:
+ 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 and no schedules tasklet. */
+ 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;
+}
+
+/* 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_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);
+
+ /* dram interrupt table not set yet,
+ * use legacy interrupt.
+ */
+ if (!trans_pcie->use_ict)
+ return iwl_isr(irq, data);
+
+ trace_iwlwifi_dev_irq(trans->dev);
+
+ spin_lock_irqsave(&trans_pcie->irq_lock, flags);
+
+ /* 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); /* just for debug */
+ 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_irq_tasklet() will service interrupts and re-enable them */
+ if (likely(inta))
+ tasklet_schedule(&trans_pcie->irq_tasklet);
+ 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;
+}