linux/drivers/s390/block/scm_blk.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Block driver for s390 storage class memory.
*
* Copyright IBM Corp. 2012
* Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
*/
#define KMSG_COMPONENT "scm_block"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <asm/eadm.h>
#include "scm_blk.h"
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;
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*");
static void __scm_free_rq(struct scm_request *scmrq)
{
struct aob_rq_header *aobrq = to_aobrq(scmrq);
free_page((unsigned long) scmrq->aob);
kfree(scmrq->request);
kfree(aobrq);
}
static void scm_free_rqs(void)
{
struct list_head *iter, *safe;
struct scm_request *scmrq;
spin_lock_irq(&list_lock);
list_for_each_safe(iter, safe, &inactive_requests) {
scmrq = list_entry(iter, struct scm_request, list);
list_del(&scmrq->list);
__scm_free_rq(scmrq);
}
spin_unlock_irq(&list_lock);
mempool_destroy(aidaw_pool);
}
static int __scm_alloc_rq(void)
{
struct aob_rq_header *aobrq;
struct scm_request *scmrq;
aobrq = kzalloc(sizeof(*aobrq) + sizeof(*scmrq), GFP_KERNEL);
if (!aobrq)
return -ENOMEM;
scmrq = (void *) aobrq->data;
scmrq->aob = (void *) get_zeroed_page(GFP_DMA);
if (!scmrq->aob)
goto free;
scmrq->request = kcalloc(nr_requests_per_io, sizeof(scmrq->request[0]),
GFP_KERNEL);
if (!scmrq->request)
goto free;
INIT_LIST_HEAD(&scmrq->list);
spin_lock_irq(&list_lock);
list_add(&scmrq->list, &inactive_requests);
spin_unlock_irq(&list_lock);
return 0;
free:
__scm_free_rq(scmrq);
return -ENOMEM;
}
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();
return ret;
}
static struct scm_request *scm_request_fetch(void)
{
struct scm_request *scmrq = NULL;
spin_lock_irq(&list_lock);
if (list_empty(&inactive_requests))
goto out;
scmrq = list_first_entry(&inactive_requests, struct scm_request, list);
list_del(&scmrq->list);
out:
spin_unlock_irq(&list_lock);
return scmrq;
}
static void scm_request_done(struct scm_request *scmrq)
{
unsigned long flags;
struct msb *msb;
u64 aidaw;
int i;
for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {
msb = &scmrq->aob->msb[i];
aidaw = msb->data_addr;
if ((msb->flags & MSB_FLAG_IDA) && aidaw &&
IS_ALIGNED(aidaw, PAGE_SIZE))
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);
}
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 inline struct aidaw *scm_aidaw_alloc(void)
{
struct page *page = mempool_alloc(aidaw_pool, GFP_ATOMIC);
return page ? page_address(page) : NULL;
}
static inline unsigned long scm_aidaw_bytes(struct aidaw *aidaw)
{
unsigned long _aidaw = (unsigned long) aidaw;
unsigned long bytes = ALIGN(_aidaw, PAGE_SIZE) - _aidaw;
return (bytes / sizeof(*aidaw)) * PAGE_SIZE;
}
struct aidaw *scm_aidaw_fetch(struct scm_request *scmrq, unsigned int bytes)
{
struct aidaw *aidaw;
if (scm_aidaw_bytes(scmrq->next_aidaw) >= bytes)
return scmrq->next_aidaw;
aidaw = scm_aidaw_alloc();
if (aidaw)
memset(aidaw, 0, PAGE_SIZE);
return aidaw;
}
static int scm_request_prepare(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
struct scm_device *scmdev = bdev->gendisk->private_data;
int pos = scmrq->aob->request.msb_count;
struct msb *msb = &scmrq->aob->msb[pos];
struct request *req = scmrq->request[pos];
struct req_iterator iter;
struct aidaw *aidaw;
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>
2013-11-24 09:19:00 +08:00
struct bio_vec bv;
aidaw = scm_aidaw_fetch(scmrq, blk_rq_bytes(req));
if (!aidaw)
return -ENOMEM;
msb->bs = MSB_BS_4K;
scmrq->aob->request.msb_count++;
msb->scm_addr = scmdev->address + ((u64) blk_rq_pos(req) << 9);
msb->oc = (rq_data_dir(req) == READ) ? MSB_OC_READ : MSB_OC_WRITE;
msb->flags |= MSB_FLAG_IDA;
msb->data_addr = (u64) aidaw;
rq_for_each_segment(bv, req, iter) {
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>
2013-11-24 09:19:00 +08:00
WARN_ON(bv.bv_offset);
msb->blk_count += bv.bv_len >> 12;
aidaw->data_addr = (u64) page_address(bv.bv_page);
aidaw++;
}
scmrq->next_aidaw = aidaw;
return 0;
}
static inline void scm_request_set(struct scm_request *scmrq,
struct request *req)
{
scmrq->request[scmrq->aob->request.msb_count] = req;
}
static inline void scm_request_init(struct scm_blk_dev *bdev,
struct scm_request *scmrq)
{
struct aob_rq_header *aobrq = to_aobrq(scmrq);
struct aob *aob = scmrq->aob;
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;
aob->request.data = (u64) aobrq;
scmrq->bdev = bdev;
scmrq->retries = 4;
scmrq->error = BLK_STS_OK;
/* We don't use all msbs - place aidaws at the end of the aob page. */
scmrq->next_aidaw = (void *) &aob->msb[nr_requests_per_io];
}
static void scm_request_requeue(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
int i;
for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++)
blk_mq_requeue_request(scmrq->request[i], false);
atomic_dec(&bdev->queued_reqs);
scm_request_done(scmrq);
blk_mq_kick_requeue_list(bdev->rq);
}
static void scm_request_finish(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
blk_status_t *error;
int i;
for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {
error = blk_mq_rq_to_pdu(scmrq->request[i]);
*error = scmrq->error;
blk_mq_complete_request(scmrq->request[i]);
}
atomic_dec(&bdev->queued_reqs);
scm_request_done(scmrq);
}
static void scm_request_start(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
atomic_inc(&bdev->queued_reqs);
if (eadm_start_aob(scmrq->aob)) {
SCM_LOG(5, "no subchannel");
scm_request_requeue(scmrq);
}
}
struct scm_queue {
struct scm_request *scmrq;
spinlock_t lock;
};
static blk_status_t scm_blk_request(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *qd)
{
struct scm_device *scmdev = hctx->queue->queuedata;
struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
struct scm_queue *sq = hctx->driver_data;
struct request *req = qd->rq;
struct scm_request *scmrq;
spin_lock(&sq->lock);
if (!scm_permit_request(bdev, req)) {
spin_unlock(&sq->lock);
return BLK_STS_RESOURCE;
}
scmrq = sq->scmrq;
if (!scmrq) {
scmrq = scm_request_fetch();
if (!scmrq) {
SCM_LOG(5, "no request");
spin_unlock(&sq->lock);
return BLK_STS_RESOURCE;
}
scm_request_init(bdev, scmrq);
sq->scmrq = scmrq;
}
scm_request_set(scmrq, req);
if (scm_request_prepare(scmrq)) {
SCM_LOG(5, "aidaw alloc failed");
scm_request_set(scmrq, NULL);
if (scmrq->aob->request.msb_count)
scm_request_start(scmrq);
sq->scmrq = NULL;
spin_unlock(&sq->lock);
return BLK_STS_RESOURCE;
}
blk_mq_start_request(req);
if (qd->last || scmrq->aob->request.msb_count == nr_requests_per_io) {
scm_request_start(scmrq);
sq->scmrq = NULL;
}
spin_unlock(&sq->lock);
return BLK_STS_OK;
}
static int scm_blk_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int idx)
{
struct scm_queue *qd = kzalloc(sizeof(*qd), GFP_KERNEL);
if (!qd)
return -ENOMEM;
spin_lock_init(&qd->lock);
hctx->driver_data = qd;
return 0;
}
static void scm_blk_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
{
struct scm_queue *qd = hctx->driver_data;
WARN_ON(qd->scmrq);
kfree(hctx->driver_data);
hctx->driver_data = NULL;
}
static void __scmrq_log_error(struct scm_request *scmrq)
{
struct aob *aob = scmrq->aob;
if (scmrq->error == BLK_STS_TIMEOUT)
SCM_LOG(1, "Request timeout");
else {
SCM_LOG(1, "Request error");
SCM_LOG_HEX(1, &aob->response, sizeof(aob->response));
}
if (scmrq->retries)
SCM_LOG(1, "Retry request");
else
pr_err("An I/O operation to SCM failed with rc=%d\n",
scmrq->error);
}
static void scm_blk_handle_error(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
unsigned long flags;
if (scmrq->error != BLK_STS_IOERR)
goto restart;
/* For -EIO the response block is valid. */
switch (scmrq->aob->response.eqc) {
case EQC_WR_PROHIBIT:
spin_lock_irqsave(&bdev->lock, flags);
if (bdev->state != SCM_WR_PROHIBIT)
pr_info("%lx: Write access to the SCM increment is suspended\n",
(unsigned long) bdev->scmdev->address);
bdev->state = SCM_WR_PROHIBIT;
spin_unlock_irqrestore(&bdev->lock, flags);
goto requeue;
default:
break;
}
restart:
if (!eadm_start_aob(scmrq->aob))
return;
requeue:
scm_request_requeue(scmrq);
}
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The bulk of the s390 patches for 4.13. Some new things but mostly bug fixes and cleanups. Noteworthy changes: - The SCM block driver is converted to blk-mq - Switch s390 to 5 level page tables. The virtual address space for a user space process can now have up to 16EB-4KB. - Introduce a ELF phdr flag for qemu to avoid the global vm.alloc_pgste which forces all processes to large page tables - A couple of PCI improvements to improve error recovery - Included is the merge of the base support for proper machine checks for KVM" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits) s390/dasd: Fix faulty ENODEV for RO sysfs attribute s390/pci: recognize name clashes with uids s390/pci: provide more debug information s390/pci: fix handling of PEC 306 s390/pci: improve pci hotplug s390/pci: introduce clp_get_state s390/pci: improve error handling during fmb (de)registration s390/pci: improve unreg_ioat error handling s390/pci: improve error handling during interrupt deregistration s390/pci: don't cleanup in arch_setup_msi_irqs KVM: s390: Backup the guest's machine check info s390/nmi: s390: New low level handling for machine check happening in guest s390/fpu: export save_fpu_regs for all configs s390/kvm: avoid global config of vm.alloc_pgste=1 s390: rename struct psw_bits members s390: rename psw_bits enums s390/mm: use correct address space when enabling DAT s390/cio: introduce io_subchannel_type s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL s390/dumpstack: remove raw stack dump ...
2017-07-04 06:39:36 +08:00
void scm_blk_irq(struct scm_device *scmdev, void *data, blk_status_t error)
{
struct scm_request *scmrq = data;
scmrq->error = error;
if (error) {
__scmrq_log_error(scmrq);
if (scmrq->retries-- > 0) {
scm_blk_handle_error(scmrq);
return;
}
}
scm_request_finish(scmrq);
}
static void scm_blk_request_done(struct request *req)
{
blk_status_t *error = blk_mq_rq_to_pdu(req);
blk_mq_end_request(req, *error);
}
static const struct block_device_operations scm_blk_devops = {
.owner = THIS_MODULE,
};
static const struct blk_mq_ops scm_mq_ops = {
.queue_rq = scm_blk_request,
.complete = scm_blk_request_done,
.init_hctx = scm_blk_init_hctx,
.exit_hctx = scm_blk_exit_hctx,
};
int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
{
unsigned int devindex, nr_max_blk;
struct request_queue *rq;
int len, ret;
devindex = atomic_inc_return(&nr_devices) - 1;
/* scma..scmz + scmaa..scmzz */
if (devindex > 701) {
ret = -ENODEV;
goto out;
}
bdev->scmdev = scmdev;
bdev->state = SCM_OPER;
spin_lock_init(&bdev->lock);
atomic_set(&bdev->queued_reqs, 0);
bdev->tag_set.ops = &scm_mq_ops;
bdev->tag_set.cmd_size = sizeof(blk_status_t);
bdev->tag_set.nr_hw_queues = nr_requests;
bdev->tag_set.queue_depth = nr_requests_per_io * nr_requests;
bdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
ret = blk_mq_alloc_tag_set(&bdev->tag_set);
if (ret)
goto out;
rq = blk_mq_init_queue(&bdev->tag_set);
if (IS_ERR(rq)) {
ret = PTR_ERR(rq);
goto out_tag;
}
bdev->rq = rq;
nr_max_blk = min(scmdev->nr_max_block,
(unsigned int) (PAGE_SIZE / sizeof(struct aidaw)));
blk_queue_logical_block_size(rq, 1 << 12);
blk_queue_max_hw_sectors(rq, nr_max_blk << 3); /* 8 * 512 = blk_size */
blk_queue_max_segments(rq, nr_max_blk);
blk_queue_flag_set(QUEUE_FLAG_NONROT, rq);
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, rq);
bdev->gendisk = alloc_disk(SCM_NR_PARTS);
if (!bdev->gendisk) {
ret = -ENOMEM;
goto out_queue;
}
rq->queuedata = scmdev;
bdev->gendisk->private_data = scmdev;
bdev->gendisk->fops = &scm_blk_devops;
bdev->gendisk->queue = rq;
bdev->gendisk->major = scm_major;
bdev->gendisk->first_minor = devindex * SCM_NR_PARTS;
len = snprintf(bdev->gendisk->disk_name, DISK_NAME_LEN, "scm");
if (devindex > 25) {
len += snprintf(bdev->gendisk->disk_name + len,
DISK_NAME_LEN - len, "%c",
'a' + (devindex / 26) - 1);
devindex = devindex % 26;
}
snprintf(bdev->gendisk->disk_name + len, DISK_NAME_LEN - len, "%c",
'a' + devindex);
/* 512 byte sectors */
set_capacity(bdev->gendisk, scmdev->size >> 9);
device_add_disk(&scmdev->dev, bdev->gendisk);
return 0;
out_queue:
blk_cleanup_queue(rq);
out_tag:
blk_mq_free_tag_set(&bdev->tag_set);
out:
atomic_dec(&nr_devices);
return ret;
}
void scm_blk_dev_cleanup(struct scm_blk_dev *bdev)
{
del_gendisk(bdev->gendisk);
blk_cleanup_queue(bdev->gendisk->queue);
blk_mq_free_tag_set(&bdev->tag_set);
put_disk(bdev->gendisk);
}
void scm_blk_set_available(struct scm_blk_dev *bdev)
{
unsigned long flags;
spin_lock_irqsave(&bdev->lock, flags);
if (bdev->state == SCM_WR_PROHIBIT)
pr_info("%lx: Write access to the SCM increment is restored\n",
(unsigned long) bdev->scmdev->address);
bdev->state = SCM_OPER;
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 true;
}
static int __init scm_blk_init(void)
{
int ret = -EINVAL;
if (!scm_blk_params_valid())
goto out;
ret = register_blkdev(0, "scm");
if (ret < 0)
goto out;
scm_major = ret;
ret = scm_alloc_rqs(nr_requests);
if (ret)
goto out_free;
scm_debug = debug_register("scm_log", 16, 1, 16);
if (!scm_debug) {
ret = -ENOMEM;
goto out_free;
}
debug_register_view(scm_debug, &debug_hex_ascii_view);
debug_set_level(scm_debug, 2);
ret = scm_drv_init();
if (ret)
goto out_dbf;
return ret;
out_dbf:
debug_unregister(scm_debug);
out_free:
scm_free_rqs();
unregister_blkdev(scm_major, "scm");
out:
return ret;
}
module_init(scm_blk_init);
static void __exit scm_blk_cleanup(void)
{
scm_drv_cleanup();
debug_unregister(scm_debug);
scm_free_rqs();
unregister_blkdev(scm_major, "scm");
}
module_exit(scm_blk_cleanup);