/*
Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
<http://rt2x00.serialmonkey.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
Module: rt2x00
Abstract: rt2x00 queue datastructures and routines
*/
#ifndef RT2X00QUEUE_H
#define RT2X00QUEUE_H
#include <linux/prefetch.h>
/**
* DOC: Entrie frame size
*
* Ralink PCI devices demand the Frame size to be a multiple of 128 bytes,
* for USB devices this restriction does not apply, but the value of
* 2432 makes sense since it is big enough to contain the maximum fragment
* size according to the ieee802.11 specs.
*/
#define DATA_FRAME_SIZE 2432
#define MGMT_FRAME_SIZE 256
/**
* DOC: Number of entries per queue
*
* Under normal load without fragmentation 12 entries are sufficient
* without the queue being filled up to the maximum. When using fragmentation
* and the queue threshold code we need to add some additional margins to
* make sure the queue will never (or only under extreme load) fill up
* completely.
* Since we don't use preallocated DMA having a large number of queue entries
* will have only minimal impact on the memory requirements for the queue.
*/
#define RX_ENTRIES 24
#define TX_ENTRIES 24
#define BEACON_ENTRIES 1
#define ATIM_ENTRIES 8
/**
* enum data_queue_qid: Queue identification
*
* @QID_AC_BE: AC BE queue
* @QID_AC_BK: AC BK queue
* @QID_AC_VI: AC VI queue
* @QID_AC_VO: AC VO queue
* @QID_HCCA: HCCA queue
* @QID_MGMT: MGMT queue (prio queue)
* @QID_RX: RX queue
* @QID_OTHER: None of the above (don't use, only present for completeness)
* @QID_BEACON: Beacon queue (value unspecified, don't send it to device)
* @QID_ATIM: Atim queue (value unspeficied, don't send it to device)
*/
enum data_queue_qid {
QID_AC_BE = 0,
QID_AC_BK = 1,
QID_AC_VI = 2,
QID_AC_VO = 3,
QID_HCCA = 4,
QID_MGMT = 13,
QID_RX = 14,
QID_OTHER = 15,
QID_BEACON,
QID_ATIM,
};
/**
* enum skb_frame_desc_flags: Flags for &struct skb_frame_desc
*
* @SKBDESC_DMA_MAPPED_RX: &skb_dma field has been mapped for RX
* @SKBDESC_DMA_MAPPED_TX: &skb_dma field has been mapped for TX
*/
enum skb_frame_desc_flags {
SKBDESC_DMA_MAPPED_RX = (1 << 0),
SKBDESC_DMA_MAPPED_TX = (1 << 1),
};
/**
* struct skb_frame_desc: Descriptor information for the skb buffer
*
* This structure is placed over the driver_data array, this means that
* this structure should not exceed the size of that array (40 bytes).
*
* @flags: Frame flags, see &enum skb_frame_desc_flags.
* @desc_len: Length of the frame descriptor.
* @desc: Pointer to descriptor part of the frame.
* Note that this pointer could point to something outside
* of the scope of the skb->data pointer.
* @skb_dma: (PCI-only) the DMA address associated with the sk buffer.
* @entry: The entry to which this sk buffer belongs.
*/
struct skb_frame_desc {
unsigned int flags;
unsigned int desc_len;
void *desc;
dma_addr_t skb_dma;
struct queue_entry *entry;
};
/**
* get_skb_frame_desc - Obtain the rt2x00 frame descriptor from a sk_buff.
* @skb: &struct sk_buff from where we obtain the &struct skb_frame_desc
*/
static inline struct skb_frame_desc* get_skb_frame_desc(struct sk_buff *skb)
{
BUILD_BUG_ON(sizeof(struct skb_frame_desc) >
IEEE80211_TX_INFO_DRIVER_DATA_SIZE);
return (struct skb_frame_desc *)&IEEE80211_SKB_CB(skb)->driver_data;
}
/**
* enum rxdone_entry_desc_flags: Flags for &struct rxdone_entry_desc
*
* @RXDONE_SIGNAL_PLCP: Does the signal field contain the plcp value,
* or does it contain the bitrate itself.
* @RXDONE_MY_BSS: Does this frame originate from device's BSS.
*/
enum rxdone_entry_desc_flags {
RXDONE_SIGNAL_PLCP = 1 << 0,
RXDONE_MY_BSS = 1 << 1,
};
/**
* struct rxdone_entry_desc: RX Entry descriptor
*
* Summary of information that has been read from the RX frame descriptor.
*
* @timestamp: RX Timestamp
* @signal: Signal of the received frame.
* @rssi: RSSI of the received frame.
* @size: Data size of the received frame.
* @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
* @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
*/
struct rxdone_entry_desc {
u64 timestamp;
int signal;
int rssi;
int size;
int flags;
int dev_flags;
};
/**
* enum txdone_entry_desc_flags: Flags for &struct txdone_entry_desc
*
* @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
* @TXDONE_SUCCESS: Frame was successfully send
* @TXDONE_FAILURE: Frame was not successfully send
* @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
* frame transmission failed due to excessive retries.
*/
enum txdone_entry_desc_flags {
TXDONE_UNKNOWN = 1 << 0,
TXDONE_SUCCESS = 1 << 1,
TXDONE_FAILURE = 1 << 2,
TXDONE_EXCESSIVE_RETRY = 1 << 3,
};
/**
* struct txdone_entry_desc: TX done entry descriptor
*
* Summary of information that has been read from the TX frame descriptor
* after the device is done with transmission.
*
* @flags: TX done flags (See &enum txdone_entry_desc_flags).
* @retry: Retry count.
*/
struct txdone_entry_desc {
unsigned long flags;
int retry;
};
/**
* enum txentry_desc_flags: Status flags for TX entry descriptor
*
* @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
* @ENTRY_TXD_CTS_FRAME: This frame is a CTS-to-self frame.
* @ENTRY_TXD_OFDM_RATE: This frame is send out with an OFDM rate.
* @ENTRY_TXD_GENERATE_SEQ: This frame requires sequence counter.
* @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
* @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
* @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
* @ENTRY_TXD_BURST: This frame belongs to the same burst event.
* @ENTRY_TXD_ACK: An ACK is required for this frame.
* @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
*/
enum txentry_desc_flags {
ENTRY_TXD_RTS_FRAME,
ENTRY_TXD_CTS_FRAME,
ENTRY_TXD_OFDM_RATE,
ENTRY_TXD_GENERATE_SEQ,
ENTRY_TXD_FIRST_FRAGMENT,
ENTRY_TXD_MORE_FRAG,
ENTRY_TXD_REQ_TIMESTAMP,
ENTRY_TXD_BURST,
ENTRY_TXD_ACK,
ENTRY_TXD_RETRY_MODE,
};
/**
* struct txentry_desc: TX Entry descriptor
*
* Summary of information for the frame descriptor before sending a TX frame.
*
* @flags: Descriptor flags (See &enum queue_entry_flags).
* @queue: Queue identification (See &enum data_queue_qid).
* @length_high: PLCP length high word.
* @length_low: PLCP length low word.
* @signal: PLCP signal.
* @service: PLCP service.
* @retry_limit: Max number of retries.
* @aifs: AIFS value.
* @ifs: IFS value.
* @cw_min: cwmin value.
* @cw_max: cwmax value.
*/
struct txentry_desc {
unsigned long flags;
enum data_queue_qid queue;
u16 length_high;
u16 length_low;
u16 signal;
u16 service;
short retry_limit;
short aifs;
short ifs;
short cw_min;
short cw_max;
};
/**
* enum queue_entry_flags: Status flags for queue entry
*
* @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
* As long as this bit is set, this entry may only be touched
* through the interface structure.
* @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
* transfer (either TX or RX depending on the queue). The entry should
* only be touched after the device has signaled it is done with it.
* @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
* encryption or decryption. The entry should only be touched after
* the device has signaled it is done with it.
* @ENTRY_DATA_PENDING: This entry contains a valid frame and is waiting
* for the signal to start sending.
*/
enum queue_entry_flags {
ENTRY_BCN_ASSIGNED,
ENTRY_OWNER_DEVICE_DATA,
ENTRY_OWNER_DEVICE_CRYPTO,
ENTRY_DATA_PENDING,
};
/**
* struct queue_entry: Entry inside the &struct data_queue
*
* @flags: Entry flags, see &enum queue_entry_flags.
* @queue: The data queue (&struct data_queue) to which this entry belongs.
* @skb: The buffer which is currently being transmitted (for TX queue),
* or used to directly recieve data in (for RX queue).
* @entry_idx: The entry index number.
* @priv_data: Private data belonging to this queue entry. The pointer
* points to data specific to a particular driver and queue type.
*/
struct queue_entry {
unsigned long flags;
struct data_queue *queue;
struct sk_buff *skb;
unsigned int entry_idx;
void *priv_data;
};
/**
* enum queue_index: Queue index type
*
* @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
* owned by the hardware then the queue is considered to be full.
* @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
* the hardware and for which we need to run the txdone handler. If this
* entry is not owned by the hardware the queue is considered to be empty.
* @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
* will be completed by the hardware next.
* @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
* of the index array.
*/
enum queue_index {
Q_INDEX,
Q_INDEX_DONE,
Q_INDEX_CRYPTO,
Q_INDEX_MAX,
};
/**
* struct data_queue: Data queue
*
* @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
* @entries: Base address of the &struct queue_entry which are
* part of this queue.
* @qid: The queue identification, see &enum data_queue_qid.
* @lock: Spinlock to protect index handling. Whenever @index, @index_done or
* @index_crypt needs to be changed this lock should be grabbed to prevent
* index corruption due to concurrency.
* @count: Number of frames handled in the queue.
* @limit: Maximum number of entries in the queue.
* @threshold: Minimum number of free entries before queue is kicked by force.
* @length: Number of frames in queue.
* @index: Index pointers to entry positions in the queue,
* use &enum queue_index to get a specific index field.
* @aifs: The aifs value for outgoing frames (field ignored in RX queue).
* @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
* @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
* @data_size: Maximum data size for the frames in this queue.
* @desc_size: Hardware descriptor size for the data in this queue.
*/
struct data_queue {
struct rt2x00_dev *rt2x00dev;
struct queue_entry *entries;
enum data_queue_qid qid;
spinlock_t lock;
unsigned int count;
unsigned short limit;
unsigned short threshold;
unsigned short length;
unsigned short index[Q_INDEX_MAX];
unsigned short aifs;
unsigned short cw_min;
unsigned short cw_max;
unsigned short data_size;
unsigned short desc_size;
};
/**
* struct data_queue_desc: Data queue description
*
* The information in this structure is used by drivers
* to inform rt2x00lib about the creation of the data queue.
*
* @entry_num: Maximum number of entries for a queue.
* @data_size: Maximum data size for the frames in this queue.
* @desc_size: Hardware descriptor size for the data in this queue.
* @priv_size: Size of per-queue_entry private data.
*/
struct data_queue_desc {
unsigned short entry_num;
unsigned short data_size;
unsigned short desc_size;
unsigned short priv_size;
};
/**
* queue_end - Return pointer to the last queue (HELPER MACRO).
* @__dev: Pointer to &struct rt2x00_dev
*
* Using the base rx pointer and the maximum number of available queues,
* this macro will return the address of 1 position beyond the end of the
* queues array.
*/
#define queue_end(__dev) \
&(__dev)->rx[(__dev)->data_queues]
/**
* tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
* @__dev: Pointer to &struct rt2x00_dev
*
* Using the base tx pointer and the maximum number of available TX
* queues, this macro will return the address of 1 position beyond
* the end of the TX queue array.
*/
#define tx_queue_end(__dev) \
&(__dev)->tx[(__dev)->ops->tx_queues]
/**
* queue_loop - Loop through the queues within a specific range (HELPER MACRO).
* @__entry: Pointer where the current queue entry will be stored in.
* @__start: Start queue pointer.
* @__end: End queue pointer.
*
* This macro will loop through all queues between &__start and &__end.
*/
#define queue_loop(__entry, __start, __end) \
for ((__entry) = (__start); \
prefetch(&(__entry)[1]), (__entry) != (__end); \
(__entry) = &(__entry)[1])
/**
* queue_for_each - Loop through all queues
* @__dev: Pointer to &struct rt2x00_dev
* @__entry: Pointer where the current queue entry will be stored in.
*
* This macro will loop through all available queues.
*/
#define queue_for_each(__dev, __entry) \
queue_loop(__entry, (__dev)->rx, queue_end(__dev))
/**
* tx_queue_for_each - Loop through the TX queues
* @__dev: Pointer to &struct rt2x00_dev
* @__entry: Pointer where the current queue entry will be stored in.
*
* This macro will loop through all TX related queues excluding
* the Beacon and Atim queues.
*/
#define tx_queue_for_each(__dev, __entry) \
queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
/**
* txall_queue_for_each - Loop through all TX related queues
* @__dev: Pointer to &struct rt2x00_dev
* @__entry: Pointer where the current queue entry will be stored in.
*
* This macro will loop through all TX related queues including
* the Beacon and Atim queues.
*/
#define txall_queue_for_each(__dev, __entry) \
queue_loop(__entry, (__dev)->tx, queue_end(__dev))
/**
* rt2x00queue_empty - Check if the queue is empty.
* @queue: Queue to check if empty.
*/
static inline int rt2x00queue_empty(struct data_queue *queue)
{
return queue->length == 0;
}
/**
* rt2x00queue_full - Check if the queue is full.
* @queue: Queue to check if full.
*/
static inline int rt2x00queue_full(struct data_queue *queue)
{
return queue->length == queue->limit;
}
/**
* rt2x00queue_free - Check the number of available entries in queue.
* @queue: Queue to check.
*/
static inline int rt2x00queue_available(struct data_queue *queue)
{
return queue->limit - queue->length;
}
/**
* rt2x00queue_threshold - Check if the queue is below threshold
* @queue: Queue to check.
*/
static inline int rt2x00queue_threshold(struct data_queue *queue)
{
return rt2x00queue_available(queue) < queue->threshold;
}
/**
* rt2x00_desc_read - Read a word from the hardware descriptor.
* @desc: Base descriptor address
* @word: Word index from where the descriptor should be read.
* @value: Address where the descriptor value should be written into.
*/
static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
{
*value = le32_to_cpu(desc[word]);
}
/**
* rt2x00_desc_write - wrote a word to the hardware descriptor.
* @desc: Base descriptor address
* @word: Word index from where the descriptor should be written.
* @value: Value that should be written into the descriptor.
*/
static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
{
desc[word] = cpu_to_le32(value);
}
#endif /* RT2X00QUEUE_H */
