s390/dasd: move dasd_ccw_req to per request data

Let the block layer allocate per request data to store
struct dasd_ccw_req. We still need extra preallocated
memory for usage by ccw programs (which vary in length)
and for requests which don't originate from the block
layer.

Link: https://lkml.kernel.org/r/20180530074130.GA6927@infradead.org
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

5 files changed, 57 insertions, 47 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 790b1fa3fec0..01a1d1dabb43 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1267,35 +1267,37 @@ struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
 }
 EXPORT_SYMBOL(dasd_kmalloc_request);
 
-struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
-                                          int datasize,
-                                          struct dasd_device *device)
+struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
+                                          struct dasd_device *device,
+                                          struct dasd_ccw_req *cqr)
 {
         unsigned long flags;
-        struct dasd_ccw_req *cqr;
-        char *data;
-        int size;
+        char *data, *chunk;
+        int size = 0;
 
-        size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
         if (cplength > 0)
                 size += cplength * sizeof(struct ccw1);
         if (datasize > 0)
                 size += datasize;
+        if (!cqr)
+                size += (sizeof(*cqr) + 7L) & -8L;
+
         spin_lock_irqsave(&device->mem_lock, flags);
-        cqr = (struct dasd_ccw_req *)
-                dasd_alloc_chunk(&device->ccw_chunks, size);
+        data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
         spin_unlock_irqrestore(&device->mem_lock, flags);
-        if (cqr == NULL)
+        if (!chunk)
                 return ERR_PTR(-ENOMEM);
-        memset(cqr, 0, sizeof(struct dasd_ccw_req));
-        data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
-        cqr->cpaddr = NULL;
+        if (!cqr) {
+                cqr = (void *) data;
+                data += (sizeof(*cqr) + 7L) & -8L;
+        }
+        memset(cqr, 0, sizeof(*cqr));
+        cqr->mem_chunk = chunk;
         if (cplength > 0) {
-                cqr->cpaddr = (struct ccw1 *) data;
-                data += cplength*sizeof(struct ccw1);
-                memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
+                cqr->cpaddr = data;
+                data += cplength * sizeof(struct ccw1);
+                memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
         }
-        cqr->data = NULL;
         if (datasize > 0) {
                 cqr->data = data;
                 memset(cqr->data, 0, datasize);
@@ -1333,7 +1335,7 @@ void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
         unsigned long flags;
 
         spin_lock_irqsave(&device->mem_lock, flags);
-        dasd_free_chunk(&device->ccw_chunks, cqr);
+        dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
         spin_unlock_irqrestore(&device->mem_lock, flags);
         dasd_put_device(device);
 }
@@ -3046,7 +3048,6 @@ static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
         cqr->callback_data = req;
         cqr->status = DASD_CQR_FILLED;
         cqr->dq = dq;
-        *((struct dasd_ccw_req **) blk_mq_rq_to_pdu(req)) = cqr;
 
         blk_mq_start_request(req);
         spin_lock(&block->queue_lock);
@@ -3077,7 +3078,7 @@ enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
         unsigned long flags;
         int rc = 0;
 
-        cqr = *((struct dasd_ccw_req **) blk_mq_rq_to_pdu(req));
+        cqr = blk_mq_rq_to_pdu(req);
         if (!cqr)
                 return BLK_EH_DONE;
 
@@ -3179,7 +3180,7 @@ static int dasd_alloc_queue(struct dasd_block *block)
         int rc;
 
         block->tag_set.ops = &dasd_mq_ops;
-        block->tag_set.cmd_size = sizeof(struct dasd_ccw_req *);
+        block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
         block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES;
         block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV;
         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
@@ -4043,7 +4044,8 @@ static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
         struct ccw1 *ccw;
         unsigned long *idaw;
 
-        cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
+        cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
+                                   NULL);
 
         if (IS_ERR(cqr)) {
                 /* internal error 13 - Allocating the RDC request failed*/
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index 131f1989f6f3..e1fe02477ea8 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -536,7 +536,8 @@ static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
         /* Build the request */
         datasize = sizeof(struct dasd_diag_req) +
                 count*sizeof(struct dasd_diag_bio);
-        cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev);
+        cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev,
+                                   blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
 
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index be208e7adcb4..bbf95b78ef5d 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -886,7 +886,7 @@ static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
         }
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* RCD */,
                                    0, /* use rcd_buf as data ara */
-                                   device);
+                                   device, NULL);
         if (IS_ERR(cqr)) {
                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                               "Could not allocate RCD request");
@@ -1442,7 +1442,7 @@ static int dasd_eckd_read_features(struct dasd_device *device)
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
                                    (sizeof(struct dasd_psf_prssd_data) +
                                     sizeof(struct dasd_rssd_features)),
-                                   device);
+                                   device, NULL);
         if (IS_ERR(cqr)) {
                 DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s", "Could not "
                                 "allocate initialization request");
@@ -1504,7 +1504,7 @@ static struct dasd_ccw_req *dasd_eckd_build_psf_ssc(struct dasd_device *device,
 
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
                                   sizeof(struct dasd_psf_ssc_data),
-                                  device);
+                                   device, NULL);
 
         if (IS_ERR(cqr)) {
                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
@@ -1815,7 +1815,8 @@ dasd_eckd_analysis_ccw(struct dasd_device *device)
 
         cplength = 8;
         datasize = sizeof(struct DE_eckd_data) + 2*sizeof(struct LO_eckd_data);
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize, device);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize, device,
+                                   NULL);
         if (IS_ERR(cqr))
                 return cqr;
         ccw = cqr->cpaddr;
@@ -2092,7 +2093,8 @@ dasd_eckd_build_check_tcw(struct dasd_device *base, struct format_data_t *fdata,
          */
         itcw_size = itcw_calc_size(0, count, 0);
 
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev,
+                                   NULL);
         if (IS_ERR(cqr))
                 return cqr;
 
@@ -2186,7 +2188,7 @@ dasd_eckd_build_check(struct dasd_device *base, struct format_data_t *fdata,
         cplength += count;
 
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
-                                  startdev);
+                                   startdev, NULL);
         if (IS_ERR(cqr))
                 return cqr;
 
@@ -2332,7 +2334,7 @@ dasd_eckd_build_format(struct dasd_device *base,
         }
         /* Allocate the format ccw request. */
         fcp = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
-                                   datasize, startdev);
+                                   datasize, startdev, NULL);
         if (IS_ERR(fcp))
                 return fcp;
 
@@ -3103,7 +3105,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
         }
         /* Allocate the ccw request. */
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
-                                   startdev);
+                                   startdev, blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
         ccw = cqr->cpaddr;
@@ -3262,7 +3264,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track(
 
         /* Allocate the ccw request. */
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
-                                   startdev);
+                                   startdev, blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
         ccw = cqr->cpaddr;
@@ -3595,7 +3597,8 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_track(
 
         /* Allocate the ccw request. */
         itcw_size = itcw_calc_size(0, ctidaw, 0);
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev,
+                                   blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
 
@@ -3862,7 +3865,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_raw(struct dasd_device *startdev,
 
         /* Allocate the ccw request. */
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
-                                   datasize, startdev);
+                                   datasize, startdev, blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
 
@@ -4102,7 +4105,7 @@ dasd_eckd_release(struct dasd_device *device)
                 return -EACCES;
 
         useglobal = 0;
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
         if (IS_ERR(cqr)) {
                 mutex_lock(&dasd_reserve_mutex);
                 useglobal = 1;
@@ -4157,7 +4160,7 @@ dasd_eckd_reserve(struct dasd_device *device)
                 return -EACCES;
 
         useglobal = 0;
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
         if (IS_ERR(cqr)) {
                 mutex_lock(&dasd_reserve_mutex);
                 useglobal = 1;
@@ -4211,7 +4214,7 @@ dasd_eckd_steal_lock(struct dasd_device *device)
                 return -EACCES;
 
         useglobal = 0;
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
         if (IS_ERR(cqr)) {
                 mutex_lock(&dasd_reserve_mutex);
                 useglobal = 1;
@@ -4271,7 +4274,8 @@ static int dasd_eckd_snid(struct dasd_device *device,
 
         useglobal = 0;
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1,
-                                   sizeof(struct dasd_snid_data), device);
+                                   sizeof(struct dasd_snid_data), device,
+                                   NULL);
         if (IS_ERR(cqr)) {
                 mutex_lock(&dasd_reserve_mutex);
                 useglobal = 1;
@@ -4331,7 +4335,7 @@ dasd_eckd_performance(struct dasd_device *device, void __user *argp)
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */  + 1 /* RSSD */,
                                    (sizeof(struct dasd_psf_prssd_data) +
                                     sizeof(struct dasd_rssd_perf_stats_t)),
-                                   device);
+                                   device, NULL);
         if (IS_ERR(cqr)) {
                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                             "Could not allocate initialization request");
@@ -4477,7 +4481,7 @@ static int dasd_symm_io(struct dasd_device *device, void __user *argp)
         psf1 = psf_data[1];
 
         /* setup CCWs for PSF + RSSD */
-        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 , 0, device);
+        cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2, 0, device, NULL);
         if (IS_ERR(cqr)) {
                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                         "Could not allocate initialization request");
@@ -5037,7 +5041,7 @@ static int dasd_eckd_read_message_buffer(struct dasd_device *device,
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
                                    (sizeof(struct dasd_psf_prssd_data) +
                                     sizeof(struct dasd_rssd_messages)),
-                                   device);
+                                   device, NULL);
         if (IS_ERR(cqr)) {
                 DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                 "Could not allocate read message buffer request");
@@ -5126,7 +5130,7 @@ static int dasd_eckd_query_host_access(struct dasd_device *device,
 
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
                                    sizeof(struct dasd_psf_prssd_data) + 1,
-                                   device);
+                                   device, NULL);
         if (IS_ERR(cqr)) {
                 DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
                                 "Could not allocate read message buffer request");
@@ -5284,8 +5288,8 @@ dasd_eckd_psf_cuir_response(struct dasd_device *device, int response,
         int rc;
 
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
-                                  sizeof(struct dasd_psf_cuir_response),
-                                  device);
+                                   sizeof(struct dasd_psf_cuir_response),
+                                   device, NULL);
 
         if (IS_ERR(cqr)) {
                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index a6b132f7e869..56007a3e7f11 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -356,7 +356,8 @@ static struct dasd_ccw_req *dasd_fba_build_cp_discard(
         datasize = sizeof(struct DE_fba_data) +
                 nr_ccws * (sizeof(struct LO_fba_data) + sizeof(struct ccw1));
 
-        cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev);
+        cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev,
+                                   blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
 
@@ -490,7 +491,8 @@ static struct dasd_ccw_req *dasd_fba_build_cp_regular(
                 datasize += (count - 1)*sizeof(struct LO_fba_data);
         }
         /* Allocate the ccw request. */
-        cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev);
+        cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev,
+                                   blk_mq_rq_to_pdu(req));
         if (IS_ERR(cqr))
                 return cqr;
         ccw = cqr->cpaddr;
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 96709b1a7bf8..0844e5e2f566 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -184,6 +184,7 @@ struct dasd_ccw_req {
         struct irb irb;                 /* device status in case of an error */
         struct dasd_ccw_req *refers;    /* ERP-chain queueing. */
         void *function;                 /* originating ERP action */
+        void *mem_chunk;
 
         /* these are for statistics only */
         unsigned long buildclk;         /* TOD-clock of request generation */
@@ -716,7 +717,7 @@ extern struct kmem_cache *dasd_page_cache;
 struct dasd_ccw_req *
 dasd_kmalloc_request(int , int, int, struct dasd_device *);
 struct dasd_ccw_req *
-dasd_smalloc_request(int , int, int, struct dasd_device *);
+dasd_smalloc_request(int, int, int, struct dasd_device *, struct dasd_ccw_req *);
 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
 void dasd_wakeup_cb(struct dasd_ccw_req *, void *);