URL
https://opencores.org/ocsvn/or1k_old/or1k_old/trunk
Subversion Repositories or1k_old
[/] [or1k_old/] [trunk/] [rc203soc/] [sw/] [uClinux/] [arch/] [armnommu/] [drivers/] [scsi/] [queue.c] - Rev 1782
Compare with Previous | Blame | View Log
/* * queue.c: queue handling primitives * * (c) 1997 Russell King * * Changelog: * 15-Sep-1997 RMK Created. * 11-Oct-1997 RMK Corrected problem with queue_remove_exclude * not updating internal linked list properly * (was causing commands to go missing). */ #define SECTOR_SIZE 512 #define __NO_VERSION__ #include <linux/module.h> #include <linux/blk.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/malloc.h> #include "scsi.h" typedef struct queue_entry { struct queue_entry *next; struct queue_entry *prev; unsigned long magic; Scsi_Cmnd *SCpnt; } QE_t; #define QUEUE_MAGIC_FREE 0xf7e1c9a3 #define QUEUE_MAGIC_USED 0xf7e1cc33 #include "queue.h" /* * Function: void queue_initialise (Queue_t *queue) * Purpose : initialise a queue * Params : queue - queue to initialise */ int queue_initialise (Queue_t *queue) { unsigned int nqueues; QE_t *q; queue->alloc = queue->free = q = (QE_t *) kmalloc (SECTOR_SIZE, GFP_KERNEL); if (q) { nqueues = SECTOR_SIZE / sizeof (QE_t); for (; nqueues; q++, nqueues--) { q->next = q + 1; q->prev = NULL; q->magic = QUEUE_MAGIC_FREE; q->SCpnt = NULL; } q -= 1; q->next = NULL; } return q != NULL; } /* * Function: void queue_free (Queue_t *queue) * Purpose : free a queue * Params : queue - queue to free */ void queue_free (Queue_t *queue) { if (queue->alloc) kfree (queue->alloc); } /* * Function: int queue_add_cmd_ordered (Queue_t *queue, Scsi_Cmnd *SCpnt) * Purpose : Add a new command onto a queue, adding REQUEST_SENSE to head. * Params : queue - destination queue * SCpnt - command to add * Returns : 0 on error, !0 on success */ int queue_add_cmd_ordered (Queue_t *queue, Scsi_Cmnd *SCpnt) { unsigned long flags; QE_t *q; save_flags_cli (flags); q = queue->free; if (q) queue->free = q->next; if (q) { if (q->magic != QUEUE_MAGIC_FREE) { restore_flags (flags); panic ("scsi queues corrupted - queue entry %p not free", q); } q->magic = QUEUE_MAGIC_USED; q->SCpnt = SCpnt; if (SCpnt->cmnd[0] == REQUEST_SENSE) { /* request_sense gets put on the queue head */ if (queue->head) { q->prev = NULL; q->next = queue->head; queue->head->prev = q; queue->head = q; } else { q->next = q->prev = NULL; queue->head = queue->tail = q; } } else { /* others get put on the tail */ if (queue->tail) { q->next = NULL; q->prev = queue->tail; queue->tail->next = q; queue->tail = q; } else { q->next = q->prev = NULL; queue->head = queue->tail = q; } } } restore_flags (flags); return q != NULL; } /* * Function: int queue_add_cmd_tail (Queue_t *queue, Scsi_Cmnd *SCpnt) * Purpose : Add a new command onto a queue, adding onto tail of list * Params : queue - destination queue * SCpnt - command to add * Returns : 0 on error, !0 on success */ int queue_add_cmd_tail (Queue_t *queue, Scsi_Cmnd *SCpnt) { unsigned long flags; QE_t *q; save_flags_cli (flags); q = queue->free; if (q) queue->free = q->next; if (q) { if (q->magic != QUEUE_MAGIC_FREE) { restore_flags (flags); panic ("scsi queues corrupted - queue entry %p not free", q); } q->magic = QUEUE_MAGIC_USED; q->SCpnt = SCpnt; if (queue->tail) { q->next = NULL; q->prev = queue->tail; queue->tail->next = q; queue->tail = q; } else { q->next = q->prev = NULL; queue->head = queue->tail = q; } } restore_flags (flags); return q != NULL; } /* * Function: Scsi_Cmnd *queue_remove_exclude (queue, exclude) * Purpose : remove a SCSI command from a queue * Params : queue - queue to remove command from * exclude - bit array of target&lun which is busy * Returns : Scsi_Cmnd if successful (and a reference), or NULL if no command available */ Scsi_Cmnd *queue_remove_exclude (Queue_t *queue, unsigned char *exclude) { unsigned long flags; Scsi_Cmnd *SCpnt; QE_t *q, *prev; save_flags_cli (flags); for (q = queue->head, prev = NULL; q; q = q->next) { if (exclude && !test_bit (q->SCpnt->target * 8 + q->SCpnt->lun, exclude)) break; prev = q; } if (q) { if (q->magic != QUEUE_MAGIC_USED) { restore_flags (flags); panic ("q_remove_exclude: scsi queues corrupted - queue entry not used"); } if (q->prev != prev) panic ("q_remove_exclude: scsi queues corrupted - q->prev != prev"); if (!prev) { queue->head = q->next; if (queue->head) queue->head->prev = NULL; else queue->tail = NULL; } else { prev->next = q->next; if (prev->next) prev->next->prev = prev; else queue->tail = prev; } SCpnt = q->SCpnt; q->next = queue->free; queue->free = q; q->magic = QUEUE_MAGIC_FREE; } else SCpnt = NULL; restore_flags (flags); return SCpnt; } /* * Function: Scsi_Cmnd *queue_remove (queue) * Purpose : removes first SCSI command from a queue * Params : queue - queue to remove command from * Returns : Scsi_Cmnd if successful (and a reference), or NULL if no command available */ Scsi_Cmnd *queue_remove (Queue_t *queue) { unsigned long flags; Scsi_Cmnd *SCpnt; QE_t *q; save_flags_cli (flags); q = queue->head; if (q) { queue->head = q->next; if (queue->head) queue->head->prev = NULL; else queue->tail = NULL; if (q->magic != QUEUE_MAGIC_USED) { restore_flags (flags); panic ("scsi queues corrupted - queue entry not used"); } SCpnt = q->SCpnt; q->next = queue->free; queue->free = q; q->magic = QUEUE_MAGIC_FREE; } else SCpnt = NULL; restore_flags (flags); return SCpnt; } /* * Function: Scsi_Cmnd *queue_remove_tgtluntag (queue, target, lun, tag) * Purpose : remove a SCSI command from the queue for a specified target/lun/tag * Params : queue - queue to remove command from * target - target that we want * lun - lun on device * tag - tag on device * Returns : Scsi_Cmnd if successful, or NULL if no command satisfies requirements */ Scsi_Cmnd *queue_remove_tgtluntag (Queue_t *queue, int target, int lun, int tag) { unsigned long flags; Scsi_Cmnd *SCpnt; QE_t *q, *prev; save_flags_cli (flags); for (q = queue->head, prev = NULL; q; q = q->next) { if (q->SCpnt->target == target && q->SCpnt->lun == lun && q->SCpnt->tag == tag) break; prev = q; } if (q) { if (q->magic != QUEUE_MAGIC_USED) { restore_flags (flags); panic ("q_remove_tgtluntag: scsi queues corrupted - queue entry not used"); } if (q->prev != prev) panic ("q_remove_tgtluntag: scsi queues corrupted - q->prev != prev"); if (!prev) { queue->head = q->next; if (queue->head) queue->head->prev = NULL; else queue->tail = NULL; } else { prev->next = q->next; if (prev->next) prev->next->prev = prev; else queue->tail = prev; } SCpnt = q->SCpnt; q->magic = QUEUE_MAGIC_FREE; q->next = queue->free; queue->free = q; } else SCpnt = NULL; restore_flags (flags); return SCpnt; } /* * Function: int queue_probetgtlun (queue, target, lun) * Purpose : check to see if we have a command in the queue for the specified * target/lun. * Params : queue - queue to look in * target - target we want to probe * lun - lun on target * Returns : 0 if not found, != 0 if found */ int queue_probetgtlun (Queue_t *queue, int target, int lun) { QE_t *q; for (q = queue->head; q; q = q->next) if (q->SCpnt->target == target && q->SCpnt->lun == lun) break; return q != NULL; } /* * Function: int queue_cmdonqueue (queue, SCpnt) * Purpose : check to see if we have a command on the queue * Params : queue - queue to look in * SCpnt - command to find * Returns : 0 if not found, != 0 if found */ int queue_cmdonqueue (Queue_t *queue, Scsi_Cmnd *SCpnt) { QE_t *q; for (q = queue->head; q; q = q->next) if (q->SCpnt == SCpnt) break; return q != NULL; } /* * Function: int queue_removecmd (Queue_t *queue, Scsi_Cmnd *SCpnt) * Purpose : remove a specific command from the queues * Params : queue - queue to look in * SCpnt - command to find * Returns : 0 if not found */ int queue_removecmd (Queue_t *queue, Scsi_Cmnd *SCpnt) { unsigned long flags; QE_t *q, *prev; save_flags_cli (flags); for (q = queue->head, prev = NULL; q; q = q->next) { if (q->SCpnt == SCpnt) break; prev = q; } if (q) { if (q->magic != QUEUE_MAGIC_USED) { restore_flags (flags); panic ("q_removecmd: scsi queues corrupted - queue entry not used"); } if (q->prev != prev) panic ("q_removecmd: scsi queues corrupted - q->prev != prev"); if (!prev) { queue->head = q->next; if (queue->head) queue->head->prev = NULL; else queue->tail = NULL; } else { prev->next = q->next; if (prev->next) prev->next->prev = prev; else queue->tail = prev; } q->magic = QUEUE_MAGIC_FREE; q->next = queue->free; queue->free = q; } restore_flags (flags); return q != NULL; }