blk_queue_dma_alignment – set dma length and memory alignment Synopsis void blk_queue_dma_alignment(struct request_queue *q, int mask); Arguments q the request queue for the device mask alignment mask Description set required memory and length alignment for direct dma transactions. this is used when building direct io requests for the queue. Copyright
blk_queue_chunk_sectors – set size of the chunk for this queue Synopsis void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors); Arguments q the request queue for the device chunk_sectors chunk sectors in the usual 512b unit Description If a driver doesn’t want IOs to cross a given chunk size, it can set this limit and prevent merging…
blk_queue_bypass_start – enter queue bypass mode Synopsis void blk_queue_bypass_start(struct request_queue *q); Arguments q queue of interest Description In bypass mode, only the dispatch FIFO queue of q is used. This function makes q enter bypass mode and drains all requests which were throttled or issued before. On return, it’s guaranteed that no request is being…
blk_queue_bypass_end – leave queue bypass mode Synopsis void blk_queue_bypass_end(struct request_queue *q); Arguments q queue of interest Description Leave bypass mode and restore the normal queueing behavior. Copyright
blk_queue_bounce_limit – set bounce buffer limit for queue Synopsis void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr); Arguments q the request queue for the device max_addr the maximum address the device can handle Description Different hardware can have different requirements as to what pages it can do I/O directly to. A low level driver can call blk_queue_bounce_limit…
blk_queue_alignment_offset – set physical block alignment offset Synopsis void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset); Arguments q the request queue for the device offset alignment offset in bytes Description Some devices are naturally misaligned to compensate for things like the legacy DOS partition table 63-sector offset. Low-level drivers should call this function for devices whose…
blk_pre_runtime_suspend – Pre runtime suspend check Synopsis int blk_pre_runtime_suspend(struct request_queue *q); Arguments q the queue of the device Description This function will check if runtime suspend is allowed for the device by examining if there are any requests pending in the queue. If there are requests pending, the device can not be runtime suspended; otherwise,…
blk_pre_runtime_resume – Pre runtime resume processing Synopsis void blk_pre_runtime_resume(struct request_queue *q); Arguments q the queue of the device Description Update the queue’s runtime status to RESUMING in preparation for the runtime resume of the device. This function should be called near the start of the device’s runtime_resume callback. Copyright
blk_post_runtime_suspend – Post runtime suspend processing Synopsis void blk_post_runtime_suspend(struct request_queue *q, int err); Arguments q the queue of the device err return value of the device’s runtime_suspend function Description Update the queue’s runtime status according to the return value of the device’s runtime suspend function and mark last busy for the device so that PM…
blk_post_runtime_resume – Post runtime resume processing Synopsis void blk_post_runtime_resume(struct request_queue *q, int err); Arguments q the queue of the device err return value of the device’s runtime_resume function Description Update the queue’s runtime status according to the return value of the device’s runtime_resume function. If it is successfully resumed, process the requests that are queued…
blk_pm_runtime_init – Block layer runtime PM initialization routine Synopsis void blk_pm_runtime_init(struct request_queue *q, struct device *dev); Arguments q the queue of the device dev the device the queue belongs to Description Initialize runtime-PM-related fields for q and start auto suspend for dev. Drivers that want to take advantage of request-based runtime PM should call this…
blk_peek_request – peek at the top of a request queue Synopsis struct request *blk_peek_request(struct request_queue *q); Arguments q request queue to peek at Description Return the request at the top of q. The returned request should be started using blk_start_request before LLD starts processing it. Return Pointer to the request at the top of q…
blk_mangle_minor – scatter minor numbers apart Synopsis int blk_mangle_minor(int minor); Arguments minor minor number to mangle Description Scatter consecutively allocated minor number apart if MANGLE_DEVT is enabled. Mangling twice gives the original value. Return Mangled value. Context Don’t care. Copyright
blk_lld_busy – Check if underlying low-level drivers of a device are busy Synopsis int blk_lld_busy(struct request_queue *q); Arguments q the queue of the device being checked Description Check if underlying low-level drivers of a device are busy. If the drivers want to export their busy state, they must set own exporting function using blk_queue_lld_busy first….
blk_limits_io_opt – set optimal request size for a device Synopsis void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); Arguments limits the queue limits opt smallest I/O size in bytes Description Storage devices may report an optimal I/O size, which is the device’s preferred unit for sustained I/O. This is rarely reported for disk drives. For RAID…
blk_limits_io_min – set minimum request size for a device Synopsis void blk_limits_io_min(struct queue_limits *limits, unsigned int min); Arguments limits the queue limits min smallest I/O size in bytes Description Some devices have an internal block size bigger than the reported hardware sector size. This function can be used to signal the smallest I/O the device…
blk_integrity_unregister – Unregister block integrity profile Synopsis void blk_integrity_unregister(struct gendisk *disk); Arguments disk disk whose integrity profile to unregister Description This function unregisters the integrity capability from a block device. Copyright
blk_integrity_register – Register a gendisk as being integrity-capable Synopsis void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template); Arguments disk struct gendisk pointer to make integrity-aware template block integrity profile to register Description When a device needs to advertise itself as being able to send/receive integrity metadata it must use this function to register the capability with…
blk_integrity_compare – Compare integrity profile of two disks Synopsis int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2); Arguments gd1 Disk to compare gd2 Disk to compare Description Meta-devices like DM and MD need to verify that all sub-devices use the same integrity format before advertising to upper layers that they can send/receive integrity metadata. This function…
blk_insert_cloned_request – Helper for stacking drivers to submit a request Synopsis int blk_insert_cloned_request(struct request_queue *q, struct request *rq); Arguments q the queue to submit the request rq the request being queued Copyright