linux/drivers/s390/block/scm_blk_cluster.c
Kent Overstreet 7988613b0e block: Convert bio_for_each_segment() to bvec_iter
More prep work for immutable biovecs - with immutable bvecs drivers
won't be able to use the biovec directly, they'll need to use helpers
that take into account bio->bi_iter.bi_bvec_done.

This updates callers for the new usage without changing the
implementation yet.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: Jim Paris <jim@jtan.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: support@lsi.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
Cc: cbe-oss-dev@lists.ozlabs.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: DL-MPTFusionLinux@lsi.com
Cc: linux-scsi@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-fsdevel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mm@kvack.org
Acked-by: Geoff Levand <geoff@infradead.org>
2013-11-23 22:33:49 -08:00

231 lines
5.4 KiB
C

/*
* Block driver for s390 storage class memory.
*
* Copyright IBM Corp. 2012
* Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <asm/eadm.h>
#include "scm_blk.h"
static unsigned int write_cluster_size = 64;
module_param(write_cluster_size, uint, S_IRUGO);
MODULE_PARM_DESC(write_cluster_size,
"Number of pages used for contiguous writes.");
#define CLUSTER_SIZE (write_cluster_size * PAGE_SIZE)
void __scm_free_rq_cluster(struct scm_request *scmrq)
{
int i;
if (!scmrq->cluster.buf)
return;
for (i = 0; i < 2 * write_cluster_size; i++)
free_page((unsigned long) scmrq->cluster.buf[i]);
kfree(scmrq->cluster.buf);
}
int __scm_alloc_rq_cluster(struct scm_request *scmrq)
{
int i;
scmrq->cluster.buf = kzalloc(sizeof(void *) * 2 * write_cluster_size,
GFP_KERNEL);
if (!scmrq->cluster.buf)
return -ENOMEM;
for (i = 0; i < 2 * write_cluster_size; i++) {
scmrq->cluster.buf[i] = (void *) get_zeroed_page(GFP_DMA);
if (!scmrq->cluster.buf[i])
return -ENOMEM;
}
INIT_LIST_HEAD(&scmrq->cluster.list);
return 0;
}
void scm_request_cluster_init(struct scm_request *scmrq)
{
scmrq->cluster.state = CLUSTER_NONE;
}
static bool clusters_intersect(struct scm_request *A, struct scm_request *B)
{
unsigned long firstA, lastA, firstB, lastB;
firstA = ((u64) blk_rq_pos(A->request) << 9) / CLUSTER_SIZE;
lastA = (((u64) blk_rq_pos(A->request) << 9) +
blk_rq_bytes(A->request) - 1) / CLUSTER_SIZE;
firstB = ((u64) blk_rq_pos(B->request) << 9) / CLUSTER_SIZE;
lastB = (((u64) blk_rq_pos(B->request) << 9) +
blk_rq_bytes(B->request) - 1) / CLUSTER_SIZE;
return (firstB <= lastA && firstA <= lastB);
}
bool scm_reserve_cluster(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
struct scm_request *iter;
if (write_cluster_size == 0)
return true;
spin_lock(&bdev->lock);
list_for_each_entry(iter, &bdev->cluster_list, cluster.list) {
if (clusters_intersect(scmrq, iter) &&
(rq_data_dir(scmrq->request) == WRITE ||
rq_data_dir(iter->request) == WRITE)) {
spin_unlock(&bdev->lock);
return false;
}
}
list_add(&scmrq->cluster.list, &bdev->cluster_list);
spin_unlock(&bdev->lock);
return true;
}
void scm_release_cluster(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
unsigned long flags;
if (write_cluster_size == 0)
return;
spin_lock_irqsave(&bdev->lock, flags);
list_del(&scmrq->cluster.list);
spin_unlock_irqrestore(&bdev->lock, flags);
}
void scm_blk_dev_cluster_setup(struct scm_blk_dev *bdev)
{
INIT_LIST_HEAD(&bdev->cluster_list);
blk_queue_io_opt(bdev->rq, CLUSTER_SIZE);
}
static void 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 bio_vec bv;
int i = 0;
u64 addr;
switch (scmrq->cluster.state) {
case CLUSTER_NONE:
scmrq->cluster.state = CLUSTER_READ;
/* fall through */
case CLUSTER_READ:
scmrq->aob->request.msb_count = 1;
msb->bs = MSB_BS_4K;
msb->oc = MSB_OC_READ;
msb->flags = MSB_FLAG_IDA;
msb->data_addr = (u64) aidaw;
msb->blk_count = write_cluster_size;
addr = scmdev->address + ((u64) blk_rq_pos(req) << 9);
msb->scm_addr = round_down(addr, CLUSTER_SIZE);
if (msb->scm_addr !=
round_down(addr + (u64) blk_rq_bytes(req) - 1,
CLUSTER_SIZE))
msb->blk_count = 2 * write_cluster_size;
for (i = 0; i < msb->blk_count; i++) {
aidaw->data_addr = (u64) scmrq->cluster.buf[i];
aidaw++;
}
break;
case CLUSTER_WRITE:
msb->oc = MSB_OC_WRITE;
for (addr = msb->scm_addr;
addr < scmdev->address + ((u64) blk_rq_pos(req) << 9);
addr += PAGE_SIZE) {
aidaw->data_addr = (u64) scmrq->cluster.buf[i];
aidaw++;
i++;
}
rq_for_each_segment(bv, req, iter) {
aidaw->data_addr = (u64) page_address(bv.bv_page);
aidaw++;
i++;
}
for (; i < msb->blk_count; i++) {
aidaw->data_addr = (u64) scmrq->cluster.buf[i];
aidaw++;
}
break;
}
}
bool scm_need_cluster_request(struct scm_request *scmrq)
{
if (rq_data_dir(scmrq->request) == READ)
return false;
return blk_rq_bytes(scmrq->request) < CLUSTER_SIZE;
}
/* Called with queue lock held. */
void scm_initiate_cluster_request(struct scm_request *scmrq)
{
scm_prepare_cluster_request(scmrq);
if (eadm_start_aob(scmrq->aob))
scm_request_requeue(scmrq);
}
bool scm_test_cluster_request(struct scm_request *scmrq)
{
return scmrq->cluster.state != CLUSTER_NONE;
}
void scm_cluster_request_irq(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
unsigned long flags;
switch (scmrq->cluster.state) {
case CLUSTER_NONE:
BUG();
break;
case CLUSTER_READ:
if (scmrq->error) {
scm_request_finish(scmrq);
break;
}
scmrq->cluster.state = CLUSTER_WRITE;
spin_lock_irqsave(&bdev->rq_lock, flags);
scm_initiate_cluster_request(scmrq);
spin_unlock_irqrestore(&bdev->rq_lock, flags);
break;
case CLUSTER_WRITE:
scm_request_finish(scmrq);
break;
}
}
bool scm_cluster_size_valid(void)
{
if (write_cluster_size == 1 || write_cluster_size > 128)
return false;
return !(write_cluster_size & (write_cluster_size - 1));
}