diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-26 16:55:27 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-26 16:55:27 -0800 |
commit | 654451748b779b28077d9058442d0f354251870d (patch) | |
tree | ff889a2f6226e16b1121789f809927666a9ccf13 /drivers/s390/scsi/zfcp_reqlist.h | |
parent | 64d497f55379b1e320a08ec2426468d96f5642ec (diff) | |
parent | 77c9cfc51b0d732b2524799810fb30018074fd60 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (158 commits)
[SCSI] Fix printing of failed 32-byte commands
[SCSI] Fix printing of variable length commands
[SCSI] libsrp: fix bug in ADDITIONAL CDB LENGTH interpretation
[SCSI] scsi_dh_alua: Add IBM Power Virtual SCSI ALUA device to dev list
[SCSI] scsi_dh_alua: add netapp to dev list
[SCSI] qla2xxx: Update version number to 8.03.02-k1.
[SCSI] qla2xxx: EEH: Restore PCI saved state during pci slot reset.
[SCSI] qla2xxx: Add firmware ETS burst support.
[SCSI] qla2xxx: Correct loop-resync issues during SNS scans.
[SCSI] qla2xxx: Correct use-after-free issue in terminate_rport_io callback.
[SCSI] qla2xxx: Correct EH bus-reset handling.
[SCSI] qla2xxx: Proper clean-up of BSG requests when request times out.
[SCSI] qla2xxx: Initialize payload receive length in failure path of vendor commands
[SCSI] fix duplicate removal on error path in scsi_sysfs_add_sdev
[SCSI] fix refcounting bug in scsi_get_host_dev
[SCSI] fix memory leak in scsi_report_lun_scan
[SCSI] lpfc: correct PPC build failure
[SCSI] raid_class: add raid1e
[SCSI] mpt2sas: Do not call sas_is_tlr_enabled for RAID volumes.
[SCSI] zfcp: Introduce header file for qdio structs and inline functions
...
Diffstat (limited to 'drivers/s390/scsi/zfcp_reqlist.h')
-rw-r--r-- | drivers/s390/scsi/zfcp_reqlist.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/s390/scsi/zfcp_reqlist.h b/drivers/s390/scsi/zfcp_reqlist.h new file mode 100644 index 00000000000..a72d1b730ab --- /dev/null +++ b/drivers/s390/scsi/zfcp_reqlist.h @@ -0,0 +1,183 @@ +/* + * zfcp device driver + * + * Data structure and helper functions for tracking pending FSF + * requests. + * + * Copyright IBM Corporation 2009 + */ + +#ifndef ZFCP_REQLIST_H +#define ZFCP_REQLIST_H + +/* number of hash buckets */ +#define ZFCP_REQ_LIST_BUCKETS 128 + +/** + * struct zfcp_reqlist - Container for request list (reqlist) + * @lock: Spinlock for protecting the hash list + * @list: Array of hashbuckets, each is a list of requests in this bucket + */ +struct zfcp_reqlist { + spinlock_t lock; + struct list_head buckets[ZFCP_REQ_LIST_BUCKETS]; +}; + +static inline int zfcp_reqlist_hash(unsigned long req_id) +{ + return req_id % ZFCP_REQ_LIST_BUCKETS; +} + +/** + * zfcp_reqlist_alloc - Allocate and initialize reqlist + * + * Returns pointer to allocated reqlist on success, or NULL on + * allocation failure. + */ +static inline struct zfcp_reqlist *zfcp_reqlist_alloc(void) +{ + unsigned int i; + struct zfcp_reqlist *rl; + + rl = kzalloc(sizeof(struct zfcp_reqlist), GFP_KERNEL); + if (!rl) + return NULL; + + spin_lock_init(&rl->lock); + + for (i = 0; i < ZFCP_REQ_LIST_BUCKETS; i++) + INIT_LIST_HEAD(&rl->buckets[i]); + + return rl; +} + +/** + * zfcp_reqlist_isempty - Check whether the request list empty + * @rl: pointer to reqlist + * + * Returns: 1 if list is empty, 0 if not + */ +static inline int zfcp_reqlist_isempty(struct zfcp_reqlist *rl) +{ + unsigned int i; + + for (i = 0; i < ZFCP_REQ_LIST_BUCKETS; i++) + if (!list_empty(&rl->buckets[i])) + return 0; + return 1; +} + +/** + * zfcp_reqlist_free - Free allocated memory for reqlist + * @rl: The reqlist where to free memory + */ +static inline void zfcp_reqlist_free(struct zfcp_reqlist *rl) +{ + /* sanity check */ + BUG_ON(!zfcp_reqlist_isempty(rl)); + + kfree(rl); +} + +static inline struct zfcp_fsf_req * +_zfcp_reqlist_find(struct zfcp_reqlist *rl, unsigned long req_id) +{ + struct zfcp_fsf_req *req; + unsigned int i; + + i = zfcp_reqlist_hash(req_id); + list_for_each_entry(req, &rl->buckets[i], list) + if (req->req_id == req_id) + return req; + return NULL; +} + +/** + * zfcp_reqlist_find - Lookup FSF request by its request id + * @rl: The reqlist where to lookup the FSF request + * @req_id: The request id to look for + * + * Returns a pointer to the FSF request with the specified request id + * or NULL if there is no known FSF request with this id. + */ +static inline struct zfcp_fsf_req * +zfcp_reqlist_find(struct zfcp_reqlist *rl, unsigned long req_id) +{ + unsigned long flags; + struct zfcp_fsf_req *req; + + spin_lock_irqsave(&rl->lock, flags); + req = _zfcp_reqlist_find(rl, req_id); + spin_unlock_irqrestore(&rl->lock, flags); + + return req; +} + +/** + * zfcp_reqlist_find_rm - Lookup request by id and remove it from reqlist + * @rl: reqlist where to search and remove entry + * @req_id: The request id of the request to look for + * + * This functions tries to find the FSF request with the specified + * id and then removes it from the reqlist. The reqlist lock is held + * during both steps of the operation. + * + * Returns: Pointer to the FSF request if the request has been found, + * NULL if it has not been found. + */ +static inline struct zfcp_fsf_req * +zfcp_reqlist_find_rm(struct zfcp_reqlist *rl, unsigned long req_id) +{ + unsigned long flags; + struct zfcp_fsf_req *req; + + spin_lock_irqsave(&rl->lock, flags); + req = _zfcp_reqlist_find(rl, req_id); + if (req) + list_del(&req->list); + spin_unlock_irqrestore(&rl->lock, flags); + + return req; +} + +/** + * zfcp_reqlist_add - Add entry to reqlist + * @rl: reqlist where to add the entry + * @req: The entry to add + * + * The request id always increases. As an optimization new requests + * are added here with list_add_tail at the end of the bucket lists + * while old requests are looked up starting at the beginning of the + * lists. + */ +static inline void zfcp_reqlist_add(struct zfcp_reqlist *rl, + struct zfcp_fsf_req *req) +{ + unsigned int i; + unsigned long flags; + + i = zfcp_reqlist_hash(req->req_id); + + spin_lock_irqsave(&rl->lock, flags); + list_add_tail(&req->list, &rl->buckets[i]); + spin_unlock_irqrestore(&rl->lock, flags); +} + +/** + * zfcp_reqlist_move - Move all entries from reqlist to simple list + * @rl: The zfcp_reqlist where to remove all entries + * @list: The list where to move all entries + */ +static inline void zfcp_reqlist_move(struct zfcp_reqlist *rl, + struct list_head *list) +{ + unsigned int i; + unsigned long flags; + + spin_lock_irqsave(&rl->lock, flags); + for (i = 0; i < ZFCP_REQ_LIST_BUCKETS; i++) + list_splice_init(&rl->buckets[i], list); + spin_unlock_irqrestore(&rl->lock, flags); +} + +#endif /* ZFCP_REQLIST_H */ |