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authorEmmanuel Grumbach <emmanuel.grumbach@intel.com>2011-07-11 10:35:34 -0400
committerWey-Yi Guy <wey-yi.w.guy@intel.com>2011-07-16 10:38:46 -0400
commitab697a9f1e73ba817955e15bd899a8a0627f9fd6 (patch)
tree238ec4488413f008da43ee9914484500f81df60f /drivers/net/wireless/iwlwifi/iwl-rx.c
parent4caab328eeea02b244765c355f9d875f8f5f6093 (diff)
iwlagn: move rx transport functions to iwl-trans-rx-pcie.c
Also create a new file: iwl-trans-int-pcie.h which will include the non static functions that are shared among the current pcie transport layer. Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Diffstat (limited to 'drivers/net/wireless/iwlwifi/iwl-rx.c')
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-rx.c136
1 files changed, 0 insertions, 136 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index bd63b785f68..05fd75fb59a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -41,142 +41,6 @@
41#include "iwl-agn-calib.h" 41#include "iwl-agn-calib.h"
42#include "iwl-agn.h" 42#include "iwl-agn.h"
43 43
44/******************************************************************************
45 *
46 * RX path functions
47 *
48 ******************************************************************************/
49
50/*
51 * Rx theory of operation
52 *
53 * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
54 * each of which point to Receive Buffers to be filled by the NIC. These get
55 * used not only for Rx frames, but for any command response or notification
56 * from the NIC. The driver and NIC manage the Rx buffers by means
57 * of indexes into the circular buffer.
58 *
59 * Rx Queue Indexes
60 * The host/firmware share two index registers for managing the Rx buffers.
61 *
62 * The READ index maps to the first position that the firmware may be writing
63 * to -- the driver can read up to (but not including) this position and get
64 * good data.
65 * The READ index is managed by the firmware once the card is enabled.
66 *
67 * The WRITE index maps to the last position the driver has read from -- the
68 * position preceding WRITE is the last slot the firmware can place a packet.
69 *
70 * The queue is empty (no good data) if WRITE = READ - 1, and is full if
71 * WRITE = READ.
72 *
73 * During initialization, the host sets up the READ queue position to the first
74 * INDEX position, and WRITE to the last (READ - 1 wrapped)
75 *
76 * When the firmware places a packet in a buffer, it will advance the READ index
77 * and fire the RX interrupt. The driver can then query the READ index and
78 * process as many packets as possible, moving the WRITE index forward as it
79 * resets the Rx queue buffers with new memory.
80 *
81 * The management in the driver is as follows:
82 * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When
83 * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
84 * to replenish the iwl->rxq->rx_free.
85 * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the
86 * iwl->rxq is replenished and the READ INDEX is updated (updating the
87 * 'processed' and 'read' driver indexes as well)
88 * + A received packet is processed and handed to the kernel network stack,
89 * detached from the iwl->rxq. The driver 'processed' index is updated.
90 * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
91 * list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
92 * INDEX is not incremented and iwl->status(RX_STALLED) is set. If there
93 * were enough free buffers and RX_STALLED is set it is cleared.
94 *
95 *
96 * Driver sequence:
97 *
98 * iwl_rx_queue_alloc() Allocates rx_free
99 * iwl_rx_replenish() Replenishes rx_free list from rx_used, and calls
100 * iwl_rx_queue_restock
101 * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx
102 * queue, updates firmware pointers, and updates
103 * the WRITE index. If insufficient rx_free buffers
104 * are available, schedules iwl_rx_replenish
105 *
106 * -- enable interrupts --
107 * ISR - iwl_rx() Detach iwl_rx_mem_buffers from pool up to the
108 * READ INDEX, detaching the SKB from the pool.
109 * Moves the packet buffer from queue to rx_used.
110 * Calls iwl_rx_queue_restock to refill any empty
111 * slots.
112 * ...
113 *
114 */
115
116/**
117 * iwl_rx_queue_space - Return number of free slots available in queue.
118 */
119int iwl_rx_queue_space(const struct iwl_rx_queue *q)
120{
121 int s = q->read - q->write;
122 if (s <= 0)
123 s += RX_QUEUE_SIZE;
124 /* keep some buffer to not confuse full and empty queue */
125 s -= 2;
126 if (s < 0)
127 s = 0;
128 return s;
129}
130
131/**
132 * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue
133 */
134void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q)
135{
136 unsigned long flags;
137 u32 reg;
138
139 spin_lock_irqsave(&q->lock, flags);
140
141 if (q->need_update == 0)
142 goto exit_unlock;
143
144 if (priv->cfg->base_params->shadow_reg_enable) {
145 /* shadow register enabled */
146 /* Device expects a multiple of 8 */
147 q->write_actual = (q->write & ~0x7);
148 iwl_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write_actual);
149 } else {
150 /* If power-saving is in use, make sure device is awake */
151 if (test_bit(STATUS_POWER_PMI, &priv->status)) {
152 reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
153
154 if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
155 IWL_DEBUG_INFO(priv,
156 "Rx queue requesting wakeup,"
157 " GP1 = 0x%x\n", reg);
158 iwl_set_bit(priv, CSR_GP_CNTRL,
159 CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
160 goto exit_unlock;
161 }
162
163 q->write_actual = (q->write & ~0x7);
164 iwl_write_direct32(priv, FH_RSCSR_CHNL0_WPTR,
165 q->write_actual);
166
167 /* Else device is assumed to be awake */
168 } else {
169 /* Device expects a multiple of 8 */
170 q->write_actual = (q->write & ~0x7);
171 iwl_write_direct32(priv, FH_RSCSR_CHNL0_WPTR,
172 q->write_actual);
173 }
174 }
175 q->need_update = 0;
176
177 exit_unlock:
178 spin_unlock_irqrestore(&q->lock, flags);
179}
180 44
181/****************************************************************************** 45/******************************************************************************
182 * 46 *