8 files changed, 203 insertions, 98 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 9d0c941b7d33..f42da9d57093 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -32,6 +32,7 @@
 #include <linux/seq_file.h>
 #include "zfcp_ext.h"
 #include "zfcp_fc.h"
+#include "zfcp_reqlist.h"
 
 #define ZFCP_BUS_ID_SIZE        20
 
@@ -49,36 +50,6 @@ static struct kmem_cache *zfcp_cache_hw_align(const char *name,
         return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
 }
 
-static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
-{
-        int idx;
-
-        adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
-                                    GFP_KERNEL);
-        if (!adapter->req_list)
-                return -ENOMEM;
-
-        for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
-                INIT_LIST_HEAD(&adapter->req_list[idx]);
-        return 0;
-}
-
-/**
- * zfcp_reqlist_isempty - is the request list empty
- * @adapter: pointer to struct zfcp_adapter
- *
- * Returns: true if list is empty, false otherwise
- */
-int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
-{
-        unsigned int idx;
-
-        for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
-                if (!list_empty(&adapter->req_list[idx]))
-                        return 0;
-        return 1;
-}
-
 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
 {
         struct ccw_device *cdev;
@@ -539,7 +510,8 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
         if (zfcp_allocate_low_mem_buffers(adapter))
                 goto failed;
 
-        if (zfcp_reqlist_alloc(adapter))
+        adapter->req_list = zfcp_reqlist_alloc();
+        if (!adapter->req_list)
                 goto failed;
 
         if (zfcp_dbf_adapter_register(adapter))
@@ -560,8 +532,6 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
         INIT_LIST_HEAD(&adapter->erp_ready_head);
         INIT_LIST_HEAD(&adapter->erp_running_head);
 
-        spin_lock_init(&adapter->req_list_lock);
-
         rwlock_init(&adapter->erp_lock);
         rwlock_init(&adapter->abort_lock);
 
diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c
index c22cb72a5ae8..6f65a2179537 100644
--- a/drivers/s390/scsi/zfcp_ccw.c
+++ b/drivers/s390/scsi/zfcp_ccw.c
@@ -10,6 +10,7 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include "zfcp_ext.h"
+#include "zfcp_reqlist.h"
 
 #define ZFCP_MODEL_PRIV 0x4
 
@@ -162,7 +163,7 @@ static int zfcp_ccw_set_online(struct ccw_device *cdev)
         }
 
         /* initialize request counter */
-        BUG_ON(!zfcp_reqlist_isempty(adapter));
+        BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
         adapter->req_no = 0;
 
         zfcp_erp_modify_adapter_status(adapter, "ccsonl1", NULL,
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 6ed48654c299..ff4e2ca19beb 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -39,9 +39,7 @@
 #include <asm/sysinfo.h>
 #include "zfcp_fsf.h"
 
-/********************* GENERAL DEFINES *********************************/
-
-#define REQUEST_LIST_SIZE 128
+struct zfcp_reqlist;
 
 /********************* SCSI SPECIFIC DEFINES *********************************/
 #define ZFCP_SCSI_ER_TIMEOUT                    (10*HZ)
@@ -206,8 +204,7 @@ struct zfcp_adapter {
         struct list_head        port_list;         /* remote port list */
         rwlock_t                port_list_lock;    /* port list lock */
         unsigned long           req_no;            /* unique FSF req number */
-        struct list_head        *req_list;         /* list of pending reqs */
-        spinlock_t              req_list_lock;     /* request list lock */
+        struct zfcp_reqlist     *req_list;
         u32                     fsf_req_seq_no;    /* FSF cmnd seq number */
         rwlock_t                abort_lock;        /* Protects against SCSI
                                                       stack abort/command
@@ -351,31 +348,4 @@ struct zfcp_data {
 #define ZFCP_SET                0x00000100
 #define ZFCP_CLEAR              0x00000200
 
-/*
- * Helper functions for request ID management.
- */
-static inline int zfcp_reqlist_hash(unsigned long req_id)
-{
-        return req_id % REQUEST_LIST_SIZE;
-}
-
-static inline void zfcp_reqlist_remove(struct zfcp_adapter *adapter,
-                                       struct zfcp_fsf_req *fsf_req)
-{
-        list_del(&fsf_req->list);
-}
-
-static inline struct zfcp_fsf_req *
-zfcp_reqlist_find(struct zfcp_adapter *adapter, unsigned long req_id)
-{
-        struct zfcp_fsf_req *request;
-        unsigned int idx;
-
-        idx = zfcp_reqlist_hash(req_id);
-        list_for_each_entry(request, &adapter->req_list[idx], list)
-                if (request->req_id == req_id)
-                        return request;
-        return NULL;
-}
-
 #endif /* ZFCP_DEF_H */
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index d40d5b0f263f..fe8e4c2b9563 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -11,6 +11,7 @@
 
 #include <linux/kthread.h>
 #include "zfcp_ext.h"
+#include "zfcp_reqlist.h"
 
 #define ZFCP_MAX_ERPS                   3
 
@@ -483,8 +484,8 @@ static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
         if (!act->fsf_req_id)
                 return;
 
-        spin_lock(&adapter->req_list_lock);
-        req = zfcp_reqlist_find(adapter, act->fsf_req_id);
+        spin_lock(&adapter->req_list->lock);
+        req = _zfcp_reqlist_find(adapter->req_list, act->fsf_req_id);
         if (req && req->erp_action == act) {
                 if (act->status & (ZFCP_STATUS_ERP_DISMISSED |
                                    ZFCP_STATUS_ERP_TIMEDOUT)) {
@@ -498,7 +499,7 @@ static void zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *act)
                         act->fsf_req_id = 0;
         } else
                 act->fsf_req_id = 0;
-        spin_unlock(&adapter->req_list_lock);
+        spin_unlock(&adapter->req_list->lock);
 }
 
 /**
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 66bdb34143cb..85cb135d5e7f 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -21,7 +21,6 @@ extern struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *);
 extern struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *, u64, u32,
                                            u32);
 extern struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *, u64);
-extern int zfcp_reqlist_isempty(struct zfcp_adapter *);
 extern void zfcp_sg_free_table(struct scatterlist *, int);
 extern int zfcp_sg_setup_table(struct scatterlist *, int);
 extern void zfcp_device_unregister(struct device *,
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index fd2371b69489..36a6f4a7b8d7 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -14,6 +14,7 @@
 #include "zfcp_ext.h"
 #include "zfcp_fc.h"
 #include "zfcp_dbf.h"
+#include "zfcp_reqlist.h"
 
 static void zfcp_fsf_request_timeout_handler(unsigned long data)
 {
@@ -457,15 +458,10 @@ static void zfcp_fsf_req_complete(struct zfcp_fsf_req *req)
 void zfcp_fsf_req_dismiss_all(struct zfcp_adapter *adapter)
 {
         struct zfcp_fsf_req *req, *tmp;
-        unsigned long flags;
         LIST_HEAD(remove_queue);
-        unsigned int i;
 
         BUG_ON(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP);
-        spin_lock_irqsave(&adapter->req_list_lock, flags);
-        for (i = 0; i < REQUEST_LIST_SIZE; i++)
-                list_splice_init(&adapter->req_list[i], &remove_queue);
-        spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+        zfcp_reqlist_move(adapter->req_list, &remove_queue);
 
         list_for_each_entry_safe(req, tmp, &remove_queue, list) {
                 list_del(&req->list);
@@ -770,27 +766,17 @@ static int zfcp_fsf_req_send(struct zfcp_fsf_req *req)
 {
         struct zfcp_adapter *adapter = req->adapter;
         struct zfcp_qdio *qdio = adapter->qdio;
-        unsigned long        flags;
-        int                  idx;
-        int                  with_qtcb = (req->qtcb != NULL);
+        int with_qtcb = (req->qtcb != NULL);
         int req_id = req->req_id;
 
-        /* put allocated FSF request into hash table */
-        spin_lock_irqsave(&adapter->req_list_lock, flags);
-        idx = zfcp_reqlist_hash(req_id);
-        list_add_tail(&req->list, &adapter->req_list[idx]);
-        spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+        zfcp_reqlist_add(adapter->req_list, req);
 
         req->queue_req.qdio_outb_usage = atomic_read(&qdio->req_q.count);
         req->issued = get_clock();
         if (zfcp_qdio_send(qdio, &req->queue_req)) {
                 del_timer(&req->timer);
-                spin_lock_irqsave(&adapter->req_list_lock, flags);
                 /* lookup request again, list might have changed */
-                req = zfcp_reqlist_find(adapter, req_id);
-                if (req)
-                        zfcp_reqlist_remove(adapter, req);
-                spin_unlock_irqrestore(&adapter->req_list_lock, flags);
+                zfcp_reqlist_find_rm(adapter->req_list, req_id);
                 zfcp_erp_adapter_reopen(adapter, 0, "fsrs__1", req);
                 return -EIO;
         }
@@ -2518,15 +2504,14 @@ void zfcp_fsf_reqid_check(struct zfcp_qdio *qdio, int sbal_idx)
         struct qdio_buffer *sbal = qdio->resp_q.sbal[sbal_idx];
         struct qdio_buffer_element *sbale;
         struct zfcp_fsf_req *fsf_req;
-        unsigned long flags, req_id;
+        unsigned long req_id;
         int idx;
 
         for (idx = 0; idx < QDIO_MAX_ELEMENTS_PER_BUFFER; idx++) {
 
                 sbale = &sbal->element[idx];
                 req_id = (unsigned long) sbale->addr;
-                spin_lock_irqsave(&adapter->req_list_lock, flags);
-                fsf_req = zfcp_reqlist_find(adapter, req_id);
+                fsf_req = zfcp_reqlist_find_rm(adapter->req_list, req_id);
 
                 if (!fsf_req)
                         /*
@@ -2536,9 +2521,6 @@ void zfcp_fsf_reqid_check(struct zfcp_qdio *qdio, int sbal_idx)
                         panic("error: unknown req_id (%lx) on adapter %s.\n",
                               req_id, dev_name(&adapter->ccw_device->dev));
 
-                list_del(&fsf_req->list);
-                spin_unlock_irqrestore(&adapter->req_list_lock, flags);
-
                 fsf_req->queue_req.sbal_response = sbal_idx;
                 fsf_req->queue_req.qdio_inb_usage =
                         atomic_read(&qdio->resp_q.count);
diff --git a/drivers/s390/scsi/zfcp_reqlist.h b/drivers/s390/scsi/zfcp_reqlist.h
new file mode 100644
index 000000000000..a72d1b730aba
--- /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 */
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 8e6fc68d6bd4..e1e56f523116 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -15,6 +15,7 @@
 #include "zfcp_ext.h"
 #include "zfcp_dbf.h"
 #include "zfcp_fc.h"
+#include "zfcp_reqlist.h"
 
 static unsigned int default_depth = 32;
 module_param_named(queue_depth, default_depth, uint, 0600);
@@ -189,9 +190,7 @@ static int zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
         /* avoid race condition between late normal completion and abort */
         write_lock_irqsave(&adapter->abort_lock, flags);
 
-        spin_lock(&adapter->req_list_lock);
-        old_req = zfcp_reqlist_find(adapter, old_reqid);
-        spin_unlock(&adapter->req_list_lock);
+        old_req = zfcp_reqlist_find(adapter->req_list, old_reqid);
         if (!old_req) {
                 write_unlock_irqrestore(&adapter->abort_lock, flags);
                 zfcp_dbf_scsi_abort("lte1", adapter->dbf, scpnt, NULL,