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path: root/drivers/net/wireless/iwlegacy/iwl-rx.c
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Diffstat (limited to 'drivers/net/wireless/iwlegacy/iwl-rx.c')
-rw-r--r--drivers/net/wireless/iwlegacy/iwl-rx.c302
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/net/wireless/iwlegacy/iwl-rx.c b/drivers/net/wireless/iwlegacy/iwl-rx.c
new file mode 100644
index 000000000000..654cf233a384
--- /dev/null
+++ b/drivers/net/wireless/iwlegacy/iwl-rx.c
@@ -0,0 +1,302 @@
+/******************************************************************************
+ *
+ * Copyright(c) 2003 - 2011 Intel Corporation. All rights reserved.
+ *
+ * Portions of this file are derived from the ipw3945 project, as well
+ * as portions of the ieee80211 subsystem header files.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
+ *
+ * The full GNU General Public License is included in this distribution in the
+ * file called LICENSE.
+ *
+ * Contact Information:
+ * Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ *****************************************************************************/
+
+#include <linux/etherdevice.h>
+#include <linux/slab.h>
+#include <net/mac80211.h>
+#include <asm/unaligned.h>
+#include "iwl-eeprom.h"
+#include "iwl-dev.h"
+#include "iwl-core.h"
+#include "iwl-sta.h"
+#include "iwl-io.h"
+#include "iwl-helpers.h"
+/************************** RX-FUNCTIONS ****************************/
+/*
+ * Rx theory of operation
+ *
+ * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
+ * each of which point to Receive Buffers to be filled by the NIC. These get
+ * used not only for Rx frames, but for any command response or notification
+ * from the NIC. The driver and NIC manage the Rx buffers by means
+ * of indexes into the circular buffer.
+ *
+ * Rx Queue Indexes
+ * The host/firmware share two index registers for managing the Rx buffers.
+ *
+ * The READ index maps to the first position that the firmware may be writing
+ * to -- the driver can read up to (but not including) this position and get
+ * good data.
+ * The READ index is managed by the firmware once the card is enabled.
+ *
+ * The WRITE index maps to the last position the driver has read from -- the
+ * position preceding WRITE is the last slot the firmware can place a packet.
+ *
+ * The queue is empty (no good data) if WRITE = READ - 1, and is full if
+ * WRITE = READ.
+ *
+ * During initialization, the host sets up the READ queue position to the first
+ * INDEX position, and WRITE to the last (READ - 1 wrapped)
+ *
+ * When the firmware places a packet in a buffer, it will advance the READ index
+ * and fire the RX interrupt. The driver can then query the READ index and
+ * process as many packets as possible, moving the WRITE index forward as it
+ * resets the Rx queue buffers with new memory.
+ *
+ * The management in the driver is as follows:
+ * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When
+ * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
+ * to replenish the iwl->rxq->rx_free.
+ * + In 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_legacy_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_legacy_rx_queue_space - Return number of free slots available in queue.
+ */
+int iwl_legacy_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;
+}
+EXPORT_SYMBOL(iwl_legacy_rx_queue_space);
+
+/**
+ * iwl_legacy_rx_queue_update_write_ptr - Update the write pointer for the RX queue
+ */
+void
+iwl_legacy_rx_queue_update_write_ptr(struct iwl_priv *priv,
+ struct iwl_rx_queue *q)
+{
+ unsigned long flags;
+ u32 rx_wrt_ptr_reg = priv->hw_params.rx_wrt_ptr_reg;
+ u32 reg;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ if (q->need_update == 0)
+ goto exit_unlock;
+
+ /* If power-saving is in use, make sure device is awake */
+ if (test_bit(STATUS_POWER_PMI, &priv->status)) {
+ reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
+
+ if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
+ IWL_DEBUG_INFO(priv,
+ "Rx queue requesting wakeup,"
+ " GP1 = 0x%x\n", reg);
+ iwl_legacy_set_bit(priv, CSR_GP_CNTRL,
+ CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
+ goto exit_unlock;
+ }
+
+ q->write_actual = (q->write & ~0x7);
+ iwl_legacy_write_direct32(priv, rx_wrt_ptr_reg,
+ q->write_actual);
+
+ /* Else device is assumed to be awake */
+ } else {
+ /* Device expects a multiple of 8 */
+ q->write_actual = (q->write & ~0x7);
+ iwl_legacy_write_direct32(priv, rx_wrt_ptr_reg,
+ q->write_actual);
+ }
+
+ q->need_update = 0;
+
+ exit_unlock:
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(iwl_legacy_rx_queue_update_write_ptr);
+
+int iwl_legacy_rx_queue_alloc(struct iwl_priv *priv)
+{
+ struct iwl_rx_queue *rxq = &priv->rxq;
+ struct device *dev = &priv->pci_dev->dev;
+ int i;
+
+ spin_lock_init(&rxq->lock);
+ INIT_LIST_HEAD(&rxq->rx_free);
+ INIT_LIST_HEAD(&rxq->rx_used);
+
+ /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
+ rxq->bd = dma_alloc_coherent(dev, 4 * RX_QUEUE_SIZE, &rxq->bd_dma,
+ GFP_KERNEL);
+ if (!rxq->bd)
+ goto err_bd;
+
+ rxq->rb_stts = dma_alloc_coherent(dev, sizeof(struct iwl_rb_status),
+ &rxq->rb_stts_dma, GFP_KERNEL);
+ if (!rxq->rb_stts)
+ goto err_rb;
+
+ /* Fill the rx_used queue with _all_ of the Rx buffers */
+ for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
+ list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
+
+ /* Set us so that we have processed and used all buffers, but have
+ * not restocked the Rx queue with fresh buffers */
+ rxq->read = rxq->write = 0;
+ rxq->write_actual = 0;
+ rxq->free_count = 0;
+ rxq->need_update = 0;
+ return 0;
+
+err_rb:
+ dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
+ rxq->bd_dma);
+err_bd:
+ return -ENOMEM;
+}
+EXPORT_SYMBOL(iwl_legacy_rx_queue_alloc);
+
+
+void iwl_legacy_rx_spectrum_measure_notif(struct iwl_priv *priv,
+ struct iwl_rx_mem_buffer *rxb)
+{
+ struct iwl_rx_packet *pkt = rxb_addr(rxb);
+ struct iwl_spectrum_notification *report = &(pkt->u.spectrum_notif);
+
+ if (!report->state) {
+ IWL_DEBUG_11H(priv,
+ "Spectrum Measure Notification: Start\n");
+ return;
+ }
+
+ memcpy(&priv->measure_report, report, sizeof(*report));
+ priv->measurement_status |= MEASUREMENT_READY;
+}
+EXPORT_SYMBOL(iwl_legacy_rx_spectrum_measure_notif);
+
+void iwl_legacy_recover_from_statistics(struct iwl_priv *priv,
+ struct iwl_rx_packet *pkt)
+{
+ if (test_bit(STATUS_EXIT_PENDING, &priv->status))
+ return;
+ if (iwl_legacy_is_any_associated(priv)) {
+ if (priv->cfg->ops->lib->check_plcp_health) {
+ if (!priv->cfg->ops->lib->check_plcp_health(
+ priv, pkt)) {
+ /*
+ * high plcp error detected
+ * reset Radio
+ */
+ iwl_legacy_force_reset(priv,
+ IWL_RF_RESET, false);
+ }
+ }
+ }
+}
+EXPORT_SYMBOL(iwl_legacy_recover_from_statistics);
+
+/*
+ * returns non-zero if packet should be dropped
+ */
+int iwl_legacy_set_decrypted_flag(struct iwl_priv *priv,
+ struct ieee80211_hdr *hdr,
+ u32 decrypt_res,
+ struct ieee80211_rx_status *stats)
+{
+ u16 fc = le16_to_cpu(hdr->frame_control);
+
+ /*
+ * All contexts have the same setting here due to it being
+ * a module parameter, so OK to check any context.
+ */
+ if (priv->contexts[IWL_RXON_CTX_BSS].active.filter_flags &
+ RXON_FILTER_DIS_DECRYPT_MSK)
+ return 0;
+
+ if (!(fc & IEEE80211_FCTL_PROTECTED))
+ return 0;
+
+ IWL_DEBUG_RX(priv, "decrypt_res:0x%x\n", decrypt_res);
+ switch (decrypt_res & RX_RES_STATUS_SEC_TYPE_MSK) {
+ case RX_RES_STATUS_SEC_TYPE_TKIP:
+ /* The uCode has got a bad phase 1 Key, pushes the packet.
+ * Decryption will be done in SW. */
+ if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
+ RX_RES_STATUS_BAD_KEY_TTAK)
+ break;
+
+ case RX_RES_STATUS_SEC_TYPE_WEP:
+ if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
+ RX_RES_STATUS_BAD_ICV_MIC) {
+ /* bad ICV, the packet is destroyed since the
+ * decryption is inplace, drop it */
+ IWL_DEBUG_RX(priv, "Packet destroyed\n");
+ return -1;
+ }
+ case RX_RES_STATUS_SEC_TYPE_CCMP:
+ if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
+ RX_RES_STATUS_DECRYPT_OK) {
+ IWL_DEBUG_RX(priv, "hw decrypt successfully!!!\n");
+ stats->flag |= RX_FLAG_DECRYPTED;
+ }
+ break;
+
+ default:
+ break;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(iwl_legacy_set_decrypted_flag);