aboutsummaryrefslogtreecommitdiff
path: root/drivers/s390/scsi/zfcp_reqlist.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-02-26 16:55:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-02-26 16:55:27 -0800
commit654451748b779b28077d9058442d0f354251870d (patch)
treeff889a2f6226e16b1121789f809927666a9ccf13 /drivers/s390/scsi/zfcp_reqlist.h
parent64d497f55379b1e320a08ec2426468d96f5642ec (diff)
parent77c9cfc51b0d732b2524799810fb30018074fd60 (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.h183
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 */