linux/drivers/s390/block/scm_blk.c
Greg Kroah-Hartman 6a55d2cdf1 s390: block: add SPDX identifiers to the remaining files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/s390/block/ files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-24 14:28:37 +01:00

591 lines
14 KiB
C

// 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;
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) {
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);
}
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);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, rq);
queue_flag_clear_unlocked(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);