3 files changed, 55 insertions, 12 deletions

diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index 56046ab39629..5b2abadea094 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -10,6 +10,7 @@
 
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
+#include <linux/mempool.h>
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/genhd.h>
@@ -20,6 +21,7 @@
 
 debug_info_t *scm_debug;
 static int scm_major;
+static mempool_t *aidaw_pool;
 static DEFINE_SPINLOCK(list_lock);
 static LIST_HEAD(inactive_requests);
 static unsigned int nr_requests = 64;
@@ -36,7 +38,6 @@ static void __scm_free_rq(struct scm_request *scmrq)
 	struct aob_rq_header *aobrq = to_aobrq(scmrq);
 
 	free_page((unsigned long) scmrq->aob);
-	free_page((unsigned long) scmrq->aidaw);
 	__scm_free_rq_cluster(scmrq);
 	kfree(aobrq);
 }
@@ -53,6 +54,8 @@ static void scm_free_rqs(void)
 		__scm_free_rq(scmrq);
 	}
 	spin_unlock_irq(&list_lock);
+
+	mempool_destroy(aidaw_pool);
 }
 
 static int __scm_alloc_rq(void)
@@ -65,9 +68,8 @@ static int __scm_alloc_rq(void)
 		return -ENOMEM;
 
 	scmrq = (void *) aobrq->data;
-	scmrq->aidaw = (void *) get_zeroed_page(GFP_DMA);
 	scmrq->aob = (void *) get_zeroed_page(GFP_DMA);
-	if (!scmrq->aob || !scmrq->aidaw) {
+	if (!scmrq->aob) {
 		__scm_free_rq(scmrq);
 		return -ENOMEM;
 	}
@@ -89,6 +91,10 @@ static int scm_alloc_rqs(unsigned int nrqs)
 {
 	int ret = 0;
 
+	aidaw_pool = mempool_create_page_pool(max(nrqs/8, 1U), 0);
+	if (!aidaw_pool)
+		return -ENOMEM;
+
 	while (nrqs-- && !ret)
 		ret = __scm_alloc_rq();
 
@@ -111,8 +117,13 @@ out:
 
 static void scm_request_done(struct scm_request *scmrq)
 {
+	struct msb *msb = &scmrq->aob->msb[0];
+	u64 aidaw = msb->data_addr;
 	unsigned long flags;
 
+	if ((msb->flags & MSB_FLAG_IDA) && aidaw)
+		mempool_free(virt_to_page(aidaw), aidaw_pool);
+
 	spin_lock_irqsave(&list_lock, flags);
 	list_add(&scmrq->list, &inactive_requests);
 	spin_unlock_irqrestore(&list_lock, flags);
@@ -123,15 +134,26 @@ static bool scm_permit_request(struct scm_blk_dev *bdev, struct request *req)
 	return rq_data_dir(req) != WRITE || bdev->state != SCM_WR_PROHIBIT;
 }
 
-static void scm_request_prepare(struct scm_request *scmrq)
+struct aidaw *scm_aidaw_alloc(void)
+{
+	struct page *page = mempool_alloc(aidaw_pool, GFP_ATOMIC);
+
+	return page ? page_address(page) : NULL;
+}
+
+static int scm_request_prepare(struct scm_request *scmrq)
 {
 	struct scm_blk_dev *bdev = scmrq->bdev;
 	struct scm_device *scmdev = bdev->gendisk->private_data;
-	struct aidaw *aidaw = scmrq->aidaw;
+	struct aidaw *aidaw = scm_aidaw_alloc();
 	struct msb *msb = &scmrq->aob->msb[0];
 	struct req_iterator iter;
 	struct bio_vec bv;
 
+	if (!aidaw)
+		return -ENOMEM;
+
+	memset(aidaw, 0, PAGE_SIZE);
 	msb->bs = MSB_BS_4K;
 	scmrq->aob->request.msb_count = 1;
 	msb->scm_addr = scmdev->address +
@@ -147,6 +169,8 @@ static void scm_request_prepare(struct scm_request *scmrq)
 		aidaw->data_addr = (u64) page_address(bv.bv_page);
 		aidaw++;
 	}
+
+	return 0;
 }
 
 static inline void scm_request_init(struct scm_blk_dev *bdev,
@@ -157,7 +181,6 @@ static inline void scm_request_init(struct scm_blk_dev *bdev,
 	struct aob *aob = scmrq->aob;
 
 	memset(aob, 0, sizeof(*aob));
-	memset(scmrq->aidaw, 0, PAGE_SIZE);
 	aobrq->scmdev = bdev->scmdev;
 	aob->request.cmd_code = ARQB_CMD_MOVE;
 	aob->request.data = (u64) aobrq;
@@ -236,7 +259,15 @@ static void scm_blk_request(struct request_queue *rq)
 			scm_initiate_cluster_request(scmrq);
 			return;
 		}
-		scm_request_prepare(scmrq);
+
+		if (scm_request_prepare(scmrq)) {
+			SCM_LOG(5, "no aidaw");
+			scm_release_cluster(scmrq);
+			scm_request_done(scmrq);
+			scm_ensure_queue_restart(bdev);
+			return;
+		}
+
 		atomic_inc(&bdev->queued_reqs);
 		blk_start_request(req);
 
diff --git a/drivers/s390/block/scm_blk.h b/drivers/s390/block/scm_blk.h
index e59331e6c2e5..a315ef0e96f5 100644
--- a/drivers/s390/block/scm_blk.h
+++ b/drivers/s390/block/scm_blk.h
@@ -31,7 +31,6 @@ struct scm_blk_dev {
 struct scm_request {
 	struct scm_blk_dev *bdev;
 	struct request *request;
-	struct aidaw *aidaw;
 	struct aob *aob;
 	struct list_head list;
 	u8 retries;
@@ -55,6 +54,8 @@ void scm_blk_irq(struct scm_device *, void *, int);
 void scm_request_finish(struct scm_request *);
 void scm_request_requeue(struct scm_request *);
 
+struct aidaw *scm_aidaw_alloc(void);
+
 int scm_drv_init(void);
 void scm_drv_cleanup(void);
 
diff --git a/drivers/s390/block/scm_blk_cluster.c b/drivers/s390/block/scm_blk_cluster.c
index 9aae909d47a5..4787f80e5537 100644
--- a/drivers/s390/block/scm_blk_cluster.c
+++ b/drivers/s390/block/scm_blk_cluster.c
@@ -114,14 +114,14 @@ void scm_blk_dev_cluster_setup(struct scm_blk_dev *bdev)
 	blk_queue_io_opt(bdev->rq, CLUSTER_SIZE);
 }
 
-static void scm_prepare_cluster_request(struct scm_request *scmrq)
+static int scm_prepare_cluster_request(struct scm_request *scmrq)
 {
 	struct scm_blk_dev *bdev = scmrq->bdev;
 	struct scm_device *scmdev = bdev->gendisk->private_data;
 	struct request *req = scmrq->request;
-	struct aidaw *aidaw = scmrq->aidaw;
 	struct msb *msb = &scmrq->aob->msb[0];
 	struct req_iterator iter;
+	struct aidaw *aidaw;
 	struct bio_vec bv;
 	int i = 0;
 	u64 addr;
@@ -131,6 +131,11 @@ static void scm_prepare_cluster_request(struct scm_request *scmrq)
 		scmrq->cluster.state = CLUSTER_READ;
 		/* fall through */
 	case CLUSTER_READ:
+		aidaw = scm_aidaw_alloc();
+		if (!aidaw)
+			return -ENOMEM;
+
+		memset(aidaw, 0, PAGE_SIZE);
 		scmrq->aob->request.msb_count = 1;
 		msb->bs = MSB_BS_4K;
 		msb->oc = MSB_OC_READ;
@@ -153,6 +158,7 @@ static void scm_prepare_cluster_request(struct scm_request *scmrq)
 
 		break;
 	case CLUSTER_WRITE:
+		aidaw = (void *) msb->data_addr;
 		msb->oc = MSB_OC_WRITE;
 
 		for (addr = msb->scm_addr;
@@ -173,6 +179,7 @@ static void scm_prepare_cluster_request(struct scm_request *scmrq)
 		}
 		break;
 	}
+	return 0;
 }
 
 bool scm_need_cluster_request(struct scm_request *scmrq)
@@ -186,9 +193,13 @@ bool scm_need_cluster_request(struct scm_request *scmrq)
 /* Called with queue lock held. */
 void scm_initiate_cluster_request(struct scm_request *scmrq)
 {
-	scm_prepare_cluster_request(scmrq);
+	if (scm_prepare_cluster_request(scmrq))
+		goto requeue;
 	if (eadm_start_aob(scmrq->aob))
-		scm_request_requeue(scmrq);
+		goto requeue;
+	return;
+requeue:
+	scm_request_requeue(scmrq);
 }
 
 bool scm_test_cluster_request(struct scm_request *scmrq)