[SCSI] zfcp: create private slab caches to guarantee proper data alignment

Create private slab caches in order to guarantee proper alignment of
data structures that get passed to hardware.

Sidenote: with this patch slab cache debugging will finally work on s390
(at least no known problems left).

Furthermore this patch does some minor cleanups:
- store ptr for transport template in struct zfcp_data

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Compile fix ups and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

5 files changed, 92 insertions, 39 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index adc9d8f2c28f..d2b094d9c34f 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -299,11 +299,45 @@ zfcp_init_device_configure(void)
         return;
 }
 
+static int calc_alignment(int size)
+{
+        int align = 1;
+
+        if (!size)
+                return 0;
+
+        while ((size - align) > 0)
+                align <<= 1;
+
+        return align;
+}
+
 static int __init
 zfcp_module_init(void)
 {
+        int retval = -ENOMEM;
+        int size, align;
+
+        size = sizeof(struct zfcp_fsf_req_qtcb);
+        align = calc_alignment(size);
+        zfcp_data.fsf_req_qtcb_cache =
+                kmem_cache_create("zfcp_fsf", size, align, 0, NULL, NULL);
+        if (!zfcp_data.fsf_req_qtcb_cache)
+                goto out;
 
-        int retval = 0;
+        size = sizeof(struct fsf_status_read_buffer);
+        align = calc_alignment(size);
+        zfcp_data.sr_buffer_cache =
+                kmem_cache_create("zfcp_sr", size, align, 0, NULL, NULL);
+        if (!zfcp_data.sr_buffer_cache)
+                goto out_sr_cache;
+
+        size = sizeof(struct zfcp_gid_pn_data);
+        align = calc_alignment(size);
+        zfcp_data.gid_pn_cache =
+                kmem_cache_create("zfcp_gid", size, align, 0, NULL, NULL);
+        if (!zfcp_data.gid_pn_cache)
+                goto out_gid_cache;
 
         atomic_set(&zfcp_data.loglevel, loglevel);
 
@@ -313,15 +347,16 @@ zfcp_module_init(void)
         /* initialize adapters to be removed list head */
         INIT_LIST_HEAD(&zfcp_data.adapter_remove_lh);
 
-        zfcp_transport_template = fc_attach_transport(&zfcp_transport_functions);
-        if (!zfcp_transport_template)
-                return -ENODEV;
+        zfcp_data.scsi_transport_template =
+                fc_attach_transport(&zfcp_transport_functions);
+        if (!zfcp_data.scsi_transport_template)
+                goto out_transport;
 
         retval = misc_register(&zfcp_cfdc_misc);
         if (retval != 0) {
                 ZFCP_LOG_INFO("registration of misc device "
                               "zfcp_cfdc failed\n");
-                goto out;
+                goto out_misc;
         }
 
         ZFCP_LOG_TRACE("major/minor for zfcp_cfdc: %d/%d\n",
@@ -333,9 +368,6 @@ zfcp_module_init(void)
         /* initialise configuration rw lock */
         rwlock_init(&zfcp_data.config_lock);
 
-        /* save address of data structure managing the driver module */
-        zfcp_data.scsi_host_template.module = THIS_MODULE;
-
         /* setup dynamic I/O */
         retval = zfcp_ccw_register();
         if (retval) {
@@ -350,6 +382,14 @@ zfcp_module_init(void)
 
  out_ccw_register:
         misc_deregister(&zfcp_cfdc_misc);
+ out_misc:
+        fc_release_transport(zfcp_data.scsi_transport_template);
+ out_transport:
+        kmem_cache_destroy(zfcp_data.gid_pn_cache);
+ out_gid_cache:
+        kmem_cache_destroy(zfcp_data.sr_buffer_cache);
+ out_sr_cache:
+        kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
  out:
         return retval;
 }
@@ -935,20 +975,20 @@ static int
 zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 {
         adapter->pool.fsf_req_erp =
-                mempool_create_kmalloc_pool(ZFCP_POOL_FSF_REQ_ERP_NR,
-                                sizeof(struct zfcp_fsf_req_pool_element));
+                mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_ERP_NR,
+                                         zfcp_data.fsf_req_qtcb_cache);
         if (!adapter->pool.fsf_req_erp)
                 return -ENOMEM;
 
         adapter->pool.fsf_req_scsi =
-                mempool_create_kmalloc_pool(ZFCP_POOL_FSF_REQ_SCSI_NR,
-                                sizeof(struct zfcp_fsf_req_pool_element));
+                mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_SCSI_NR,
+                                         zfcp_data.fsf_req_qtcb_cache);
         if (!adapter->pool.fsf_req_scsi)
                 return -ENOMEM;
 
         adapter->pool.fsf_req_abort =
-                mempool_create_kmalloc_pool(ZFCP_POOL_FSF_REQ_ABORT_NR,
-                                sizeof(struct zfcp_fsf_req_pool_element));
+                mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_ABORT_NR,
+                                         zfcp_data.fsf_req_qtcb_cache);
         if (!adapter->pool.fsf_req_abort)
                 return -ENOMEM;
 
@@ -959,14 +999,14 @@ zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
                 return -ENOMEM;
 
         adapter->pool.data_status_read =
-                mempool_create_kmalloc_pool(ZFCP_POOL_STATUS_READ_NR,
-                                        sizeof(struct fsf_status_read_buffer));
+                mempool_create_slab_pool(ZFCP_POOL_STATUS_READ_NR,
+                                         zfcp_data.sr_buffer_cache);
         if (!adapter->pool.data_status_read)
                 return -ENOMEM;
 
         adapter->pool.data_gid_pn =
-                mempool_create_kmalloc_pool(ZFCP_POOL_DATA_GID_PN_NR,
-                                            sizeof(struct zfcp_gid_pn_data));
+                mempool_create_slab_pool(ZFCP_POOL_DATA_GID_PN_NR,
+                                         zfcp_data.gid_pn_cache);
         if (!adapter->pool.data_gid_pn)
                 return -ENOMEM;
 
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 7c84b3d4bd94..ef1cd49184e8 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -19,7 +19,6 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
  */ 
 
-
 #ifndef ZFCP_DEF_H
 #define ZFCP_DEF_H
 
@@ -32,6 +31,10 @@
 #include <linux/blkdev.h>
 #include <linux/delay.h>
 #include <linux/timer.h>
+#include <linux/slab.h>
+#include <linux/mempool.h>
+#include <linux/syscalls.h>
+#include <linux/ioctl.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi_cmnd.h>
@@ -39,14 +42,11 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_transport.h>
 #include <scsi/scsi_transport_fc.h>
-#include "zfcp_fsf.h"
 #include <asm/ccwdev.h>
 #include <asm/qdio.h>
 #include <asm/debug.h>
 #include <asm/ebcdic.h>
-#include <linux/mempool.h>
-#include <linux/syscalls.h>
-#include <linux/ioctl.h>
+#include "zfcp_fsf.h"
 
 
 /********************* GENERAL DEFINES *********************************/
@@ -1016,6 +1016,7 @@ typedef void zfcp_fsf_req_handler_t(struct zfcp_fsf_req*);
 /* driver data */
 struct zfcp_data {
         struct scsi_host_template scsi_host_template;
+        struct scsi_transport_template *scsi_transport_template;
         atomic_t                status;             /* Module status flags */
         struct list_head        adapter_list_head;  /* head of adapter list */
         struct list_head        adapter_remove_lh;  /* head of adapters to be
@@ -1031,6 +1032,9 @@ struct zfcp_data {
         wwn_t                   init_wwpn;
         fcp_lun_t               init_fcp_lun;
         char                    *driver_version;
+        kmem_cache_t            *fsf_req_qtcb_cache;
+        kmem_cache_t            *sr_buffer_cache;
+        kmem_cache_t            *gid_pn_cache;
 };
 
 /**
@@ -1051,7 +1055,7 @@ struct zfcp_sg_list {
 #define ZFCP_POOL_DATA_GID_PN_NR        1
 
 /* struct used by memory pools for fsf_requests */
-struct zfcp_fsf_req_pool_element {
+struct zfcp_fsf_req_qtcb {
         struct zfcp_fsf_req fsf_req;
         struct fsf_qtcb qtcb;
 };
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index b45d1bf297a8..4f4ef0c4ca7b 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -130,7 +130,6 @@ extern int zfcp_scsi_command_async(struct zfcp_adapter *,struct zfcp_unit *,
                                    struct scsi_cmnd *, struct timer_list *);
 extern int zfcp_scsi_command_sync(struct zfcp_unit *, struct scsi_cmnd *,
                                   struct timer_list *);
-extern struct scsi_transport_template *zfcp_transport_template;
 extern struct fc_function_template zfcp_transport_functions;
 
 /******************************** ERP ****************************************/
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index ff2eacf5ec8c..4913ffbb2fc8 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -100,14 +100,19 @@ zfcp_fsf_req_alloc(mempool_t *pool, int req_flags)
         if (req_flags & ZFCP_REQ_NO_QTCB)
                 size = sizeof(struct zfcp_fsf_req);
         else
-                size = sizeof(struct zfcp_fsf_req_pool_element);
+                size = sizeof(struct zfcp_fsf_req_qtcb);
 
-        if (likely(pool != NULL))
+        if (likely(pool))
                 ptr = mempool_alloc(pool, GFP_ATOMIC);
-        else
-                ptr = kmalloc(size, GFP_ATOMIC);
+        else {
+                if (req_flags & ZFCP_REQ_NO_QTCB)
+                        ptr = kmalloc(size, GFP_ATOMIC);
+                else
+                        ptr = kmem_cache_alloc(zfcp_data.fsf_req_qtcb_cache,
+                                               SLAB_ATOMIC);
+        }
 
-        if (unlikely(NULL == ptr))
+        if (unlikely(!ptr))
                 goto out;
 
         memset(ptr, 0, size);
@@ -115,9 +120,8 @@ zfcp_fsf_req_alloc(mempool_t *pool, int req_flags)
         if (req_flags & ZFCP_REQ_NO_QTCB) {
                 fsf_req = (struct zfcp_fsf_req *) ptr;
         } else {
-                fsf_req = &((struct zfcp_fsf_req_pool_element *) ptr)->fsf_req;
-                fsf_req->qtcb =
-                        &((struct zfcp_fsf_req_pool_element *) ptr)->qtcb;
+                fsf_req = &((struct zfcp_fsf_req_qtcb *) ptr)->fsf_req;
+                fsf_req->qtcb = &((struct zfcp_fsf_req_qtcb *) ptr)->qtcb;
         }
 
         fsf_req->pool = pool;
@@ -139,10 +143,17 @@ zfcp_fsf_req_alloc(mempool_t *pool, int req_flags)
 void
 zfcp_fsf_req_free(struct zfcp_fsf_req *fsf_req)
 {
-        if (likely(fsf_req->pool != NULL))
+        if (likely(fsf_req->pool)) {
                 mempool_free(fsf_req, fsf_req->pool);
-        else
-                kfree(fsf_req);
+                return;
+        }
+
+        if (fsf_req->qtcb) {
+                kmem_cache_free(zfcp_data.fsf_req_qtcb_cache, fsf_req);
+                return;
+        }
+
+        kfree(fsf_req);
 }
 
 /**
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 1bb55086db9f..4857cccb1d5b 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -39,11 +39,10 @@ static struct zfcp_unit *zfcp_unit_lookup(struct zfcp_adapter *, int,
 
 static struct device_attribute *zfcp_sysfs_sdev_attrs[];
 
-struct scsi_transport_template *zfcp_transport_template;
-
 struct zfcp_data zfcp_data = {
         .scsi_host_template = {
                 .name                   = ZFCP_NAME,
+                .module                 = THIS_MODULE,
                 .proc_name              = "zfcp",
                 .slave_alloc            = zfcp_scsi_slave_alloc,
                 .slave_configure        = zfcp_scsi_slave_configure,
@@ -607,7 +606,7 @@ zfcp_adapter_scsi_register(struct zfcp_adapter *adapter)
         adapter->scsi_host->max_channel = 0;
         adapter->scsi_host->unique_id = unique_id++;    /* FIXME */
         adapter->scsi_host->max_cmd_len = ZFCP_MAX_SCSI_CMND_LENGTH;
-        adapter->scsi_host->transportt = zfcp_transport_template;
+        adapter->scsi_host->transportt = zfcp_data.scsi_transport_template;
 
         /*
          * save a pointer to our own adapter data structure within