From: Emmanuel Grumbach Date: Mon, 6 Feb 2012 14:41:58 +0000 (+0200) Subject: iwlwifi: document the transport layer X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=60396183a4e7adce7aa71f801e47b063fe1f70a8;p=mv-sheeva.git iwlwifi: document the transport layer Fix a few typos in the existing comments too. Enforce the comments with might_sleep. Signed-off-by: Emmanuel Grumbach Signed-off-by: Wey-Yi Guy --- diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h index 7ea5f7733d2..2a2941f9fd2 100644 --- a/drivers/net/wireless/iwlwifi/iwl-trans.h +++ b/drivers/net/wireless/iwlwifi/iwl-trans.h @@ -70,17 +70,72 @@ #include "iwl-commands.h" #include "iwl-ucode.h" - /*This file includes the declaration that are exported from the transport - * layer */ +/** + * DOC: Transport layer - what is it ? + * + * The tranport layer is the layer that deals with the HW directly. It provides + * an abstraction of the underlying HW to the upper layer. The transport layer + * doesn't provide any policy, algorithm or anything of this kind, but only + * mechanisms to make the HW do something.It is not completely stateless but + * close to it. + * We will have an implementation for each different supported bus. + */ + +/** + * DOC: Life cycle of the transport layer + * + * The transport layer has a very precise life cycle. + * + * 1) A helper function is called during the module initialization and + * registers the bus driver's ops with the transport's alloc function. + * 2) Bus's probe calls to the transport layer's allocation functions. + * Of course this function is bus specific. + * 3) This allocation functions will spawn the upper layer which will + * register mac80211. + * + * 4) At some point (i.e. mac80211's start call), the op_mode will call + * the following sequence: + * start_hw + * start_fw + * + * 5) Then when finished (or reset): + * stop_fw (a.k.a. stop device for the moment) + * stop_hw + * + * 6) Eventually, the free function will be called. + */ + +/** + * DOC: API needed by the transport layer from the op_mode + * + * TODO + */ struct iwl_priv; struct iwl_shared; +/** + * DOC: Host command section + * + * A host command is a commaned issued by the upper layer to the fw. There are + * several versions of fw that have several APIs. The transport layer is + * completely agnostic to these differences. + * The transport does provide helper functionnality (i.e. SYNC / ASYNC mode), + */ #define SEQ_TO_SN(seq) (((seq) & IEEE80211_SCTL_SEQ) >> 4) #define SN_TO_SEQ(ssn) (((ssn) << 4) & IEEE80211_SCTL_SEQ) #define MAX_SN ((IEEE80211_SCTL_SEQ) >> 4) -enum { +/** + * enum CMD_MODE - how to send the host commands ? + * + * @CMD_SYNC: The caller will be stalled until the fw responds to the command + * @CMD_ASYNC: Return right away and don't want for the response + * @CMD_WANT_SKB: valid only with CMD_SYNC. The caller needs the buffer of the + * response. + * @CMD_ON_DEMAND: This command is sent by the test mode pipe. + */ +enum CMD_MODE { CMD_SYNC = 0, CMD_ASYNC = BIT(0), CMD_WANT_SKB = BIT(1), @@ -105,20 +160,29 @@ struct iwl_device_cmd { #define IWL_MAX_CMD_TFDS 2 +/** + * struct iwl_hcmd_dataflag - flag for each one of the chunks of the command + * + * IWL_HCMD_DFL_NOCOPY: By default, the command is copied to the host command's + * ring. The transport layer doesn't map the command's buffer to DMA, but + * rather copies it to an previously allocated DMA buffer. This flag tells + * the transport layer not to copy the command, but to map the existing + * buffer. This can save memcpy and is worth with very big comamnds. + */ enum iwl_hcmd_dataflag { IWL_HCMD_DFL_NOCOPY = BIT(0), }; /** * struct iwl_host_cmd - Host command to the uCode + * * @data: array of chunks that composes the data of the host command * @reply_page: pointer to the page that holds the response to the host command * @handler_status: return value of the handler of the command * (put in setup_rx_handlers) - valid for SYNC mode only - * @callback: - * @flags: can be CMD_* note CMD_WANT_SKB is incompatible withe CMD_ASYNC + * @flags: can be CMD_* * @len: array of the lenths of the chunks in data - * @dataflags: + * @dataflags: IWL_HCMD_DFL_* * @id: id of the host command */ struct iwl_host_cmd { @@ -134,26 +198,43 @@ struct iwl_host_cmd { /** * struct iwl_trans_ops - transport specific operations + * + * All the handlers MUST be implemented + * * @start_hw: starts the HW- from that point on, the HW can send interrupts + * May sleep * @stop_hw: stops the HW- from that point on, the HW will be in low power but * will still issue interrupt if the HW RF kill is triggered. + * May sleep * @start_fw: allocates and inits all the resources for the transport - * layer. Also kick a fw image. This handler may sleep. + * layer. Also kick a fw image. + * May sleep * @fw_alive: called when the fw sends alive notification + * May sleep * @wake_any_queue: wake all the queues of a specfic context IWL_RXON_CTX_* * @stop_device:stops the whole device (embedded CPU put to reset) + * May sleep * @send_cmd:send a host command + * May sleep only if CMD_SYNC is set * @tx: send an skb + * Must be atomic * @reclaim: free packet until ssn. Returns a list of freed packets. + * Must be atomic * @tx_agg_alloc: allocate resources for a TX BA session + * May sleep * @tx_agg_setup: setup a tx queue for AMPDU - will be called once the HW is - * ready and a successful ADDBA response has been received. + * ready and a successful ADDBA response has been received. + * May sleep * @tx_agg_disable: de-configure a Tx queue to send AMPDUs + * May sleep * @free: release all the ressource for the transport layer itself such as - * irq, tasklet etc... + * irq, tasklet etc... From this point on, the device may not issue + * any interrupt (incl. RFKILL). + * May sleep * @stop_queue: stop a specific queue * @check_stuck_queue: check if a specific queue is stuck * @wait_tx_queue_empty: wait until all tx queues are empty + * May sleep * @dbgfs_register: add the dbgfs files under this directory. Files will be * automatically deleted. * @suspend: stop the device unless WoWLAN is configured @@ -217,6 +298,7 @@ struct iwl_calib_result { /** * struct iwl_trans - transport common data + * * @ops - pointer to iwl_trans_ops * @shrd - pointer to iwl_shared which holds shared data from the upper layer * @hcmd_lock: protects HCMD @@ -224,7 +306,7 @@ struct iwl_calib_result { * @dev - pointer to struct device * that represents the device * @irq - the irq number for the device * @hw_id: a u32 with the ID of the device / subdevice. - * Set during transport alloaction. + * Set during transport allocation. * @hw_id_str: a string with info about HW ID. Set during transport allocation. * @ucode_write_complete: indicates that the ucode has been copied. * @ucode_rt: run time ucode image @@ -246,13 +328,11 @@ struct iwl_trans { u32 hw_id; char hw_id_str[52]; - u8 ucode_write_complete; /* the image write is complete */ + u8 ucode_write_complete; - /* eeprom related variables */ int nvm_device_type; bool pm_support; - /* init calibration results */ struct list_head calib_results; /* pointer to trans specific struct */ @@ -262,16 +342,22 @@ struct iwl_trans { static inline int iwl_trans_start_hw(struct iwl_trans *trans) { + might_sleep(); + return trans->ops->start_hw(trans); } static inline void iwl_trans_stop_hw(struct iwl_trans *trans) { + might_sleep(); + trans->ops->stop_hw(trans); } static inline void iwl_trans_fw_alive(struct iwl_trans *trans) { + might_sleep(); + trans->ops->fw_alive(trans); } @@ -284,6 +370,8 @@ static inline int iwl_trans_start_fw(struct iwl_trans *trans, struct fw_img *fw) static inline void iwl_trans_stop_device(struct iwl_trans *trans) { + might_sleep(); + trans->ops->stop_device(trans); } @@ -322,12 +410,16 @@ static inline int iwl_trans_reclaim(struct iwl_trans *trans, int sta_id, static inline int iwl_trans_tx_agg_disable(struct iwl_trans *trans, int sta_id, int tid) { + might_sleep(); + return trans->ops->tx_agg_disable(trans, sta_id, tid); } static inline int iwl_trans_tx_agg_alloc(struct iwl_trans *trans, int sta_id, int tid) { + might_sleep(); + return trans->ops->tx_agg_alloc(trans, sta_id, tid); } @@ -337,6 +429,8 @@ static inline void iwl_trans_tx_agg_setup(struct iwl_trans *trans, int sta_id, int tid, int frame_limit, u16 ssn) { + might_sleep(); + trans->ops->tx_agg_setup(trans, ctx, sta_id, tid, frame_limit, ssn); }