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Commit 8622384f authored by Sebastian Ott's avatar Sebastian Ott Committed by Martin Schwidefsky
Browse files

s390/scm_block: make the number of reqs per HW req configurable 



Introduce a module parameter to specify the number of requests
we try to handle with one HW request.

Suggested-by: default avatarPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent bbc610a9

drivers/s390/block/scm_blk.c

+33 −15
Original line number Diff line number Diff line
@@ -25,10 +25,14 @@ static mempool_t *aidaw_pool; 
static DEFINE_SPINLOCK(list_lock);

static LIST_HEAD(inactive_requests);

static unsigned int nr_requests = 64;

static unsigned int nr_requests_per_io = 8;

static atomic_t nr_devices = ATOMIC_INIT(0);

module_param(nr_requests, uint, S_IRUGO);

MODULE_PARM_DESC(nr_requests, "Number of parallel requests.");



module_param(nr_requests_per_io, uint, S_IRUGO);

MODULE_PARM_DESC(nr_requests_per_io, "Number of requests per IO.");



MODULE_DESCRIPTION("Block driver for s390 storage class memory.");

MODULE_LICENSE("GPL");

MODULE_ALIAS("scm:scmdev*");
@@ -39,6 +43,7 @@ static void __scm_free_rq(struct scm_request *scmrq) 


	free_page((unsigned long) scmrq->aob);

	__scm_free_rq_cluster(scmrq);

	kfree(scmrq->request);

	kfree(aobrq);

}
@@ -69,15 +74,16 @@ static int __scm_alloc_rq(void) 


	scmrq = (void *) aobrq->data;

	scmrq->aob = (void *) get_zeroed_page(GFP_DMA);

	if (!scmrq->aob) {

		__scm_free_rq(scmrq);

		return -ENOMEM;

	}

	if (!scmrq->aob)

		goto free;



	if (__scm_alloc_rq_cluster(scmrq)) {

		__scm_free_rq(scmrq);

		return -ENOMEM;

	}

	scmrq->request = kcalloc(nr_requests_per_io, sizeof(scmrq->request[0]),

				 GFP_KERNEL);

	if (!scmrq->request)

		goto free;



	if (__scm_alloc_rq_cluster(scmrq))

		goto free;



	INIT_LIST_HEAD(&scmrq->list);

	spin_lock_irq(&list_lock);
@@ -85,6 +91,9 @@ static int __scm_alloc_rq(void) 
	spin_unlock_irq(&list_lock);



	return 0;

free:

	__scm_free_rq(scmrq);

	return -ENOMEM;

}



static int scm_alloc_rqs(unsigned int nrqs)
@@ -122,7 +131,7 @@ static void scm_request_done(struct scm_request *scmrq) 
	u64 aidaw;

	int i;



	for (i = 0; i < SCM_RQ_PER_IO && scmrq->request[i]; i++) {

	for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {

		msb = &scmrq->aob->msb[i];

		aidaw = msb->data_addr;
@@ -214,7 +223,8 @@ static inline void scm_request_init(struct scm_blk_dev *bdev, 
	struct aob_rq_header *aobrq = to_aobrq(scmrq);

	struct aob *aob = scmrq->aob;



	memset(scmrq->request, 0, sizeof(scmrq->request));

	memset(scmrq->request, 0,

	       nr_requests_per_io * sizeof(scmrq->request[0]));

	memset(aob, 0, sizeof(*aob));

	aobrq->scmdev = bdev->scmdev;

	aob->request.cmd_code = ARQB_CMD_MOVE;
@@ -223,7 +233,7 @@ static inline void scm_request_init(struct scm_blk_dev *bdev, 
	scmrq->retries = 4;

	scmrq->error = 0;

	/* We don't use all msbs - place aidaws at the end of the aob page. */

	scmrq->next_aidaw = (void *) &aob->msb[SCM_RQ_PER_IO];

	scmrq->next_aidaw = (void *) &aob->msb[nr_requests_per_io];

	scm_request_cluster_init(scmrq);

}
@@ -242,7 +252,7 @@ void scm_request_requeue(struct scm_request *scmrq) 
	int i;



	scm_release_cluster(scmrq);

	for (i = 0; i < SCM_RQ_PER_IO && scmrq->request[i]; i++)

	for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++)

		blk_requeue_request(bdev->rq, scmrq->request[i]);



	atomic_dec(&bdev->queued_reqs);
@@ -256,7 +266,7 @@ void scm_request_finish(struct scm_request *scmrq) 
	int i;



	scm_release_cluster(scmrq);

	for (i = 0; i < SCM_RQ_PER_IO && scmrq->request[i]; i++)

	for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++)

		blk_end_request_all(scmrq->request[i], scmrq->error);



	atomic_dec(&bdev->queued_reqs);
@@ -342,7 +352,7 @@ static void scm_blk_request(struct request_queue *rq) 
		}

		blk_start_request(req);



		if (scmrq->aob->request.msb_count < SCM_RQ_PER_IO)

		if (scmrq->aob->request.msb_count < nr_requests_per_io)

			continue;



		if (scm_request_start(scmrq))
@@ -551,11 +561,19 @@ void scm_blk_set_available(struct scm_blk_dev *bdev) 
	spin_unlock_irqrestore(&bdev->lock, flags);

}



static bool __init scm_blk_params_valid(void)

{

	if (!nr_requests_per_io || nr_requests_per_io > 64)

		return false;



	return scm_cluster_size_valid();

}



static int __init scm_blk_init(void)

{

	int ret = -EINVAL;



	if (!scm_cluster_size_valid())

	if (!scm_blk_params_valid())

		goto out;



	ret = register_blkdev(0, "scm");

drivers/s390/block/scm_blk.h

+1 −2
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#include <asm/eadm.h>



#define SCM_NR_PARTS 8

#define SCM_RQ_PER_IO 8

#define SCM_QUEUE_DELAY 5



struct scm_blk_dev {
@@ -32,7 +31,7 @@ struct scm_blk_dev { 
struct scm_request {

	struct scm_blk_dev *bdev;

	struct aidaw *next_aidaw;

	struct request *request[SCM_RQ_PER_IO];

	struct request **request;

	struct aob *aob;

	struct list_head list;

	u8 retries;