s390/scm_block: force cluster writes
Force writes to Storage Class Memory (SCM) to be in done in clusters. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott
Martin Schwidefsky
Родитель
f30664e2c8
Коммит
0d804b2073
|
|
@ -81,3 +81,10 @@ config SCM_BLOCK
|
|||
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called scm_block.
|
||||
|
||||
config SCM_BLOCK_CLUSTER_WRITE
|
||||
def_bool y
|
||||
prompt "SCM force cluster writes"
|
||||
depends on SCM_BLOCK
|
||||
help
|
||||
Force writes to Storage Class Memory (SCM) to be in done in clusters.
|
||||
|
|
|
|||
|
|
@ -19,4 +19,7 @@ obj-$(CONFIG_BLK_DEV_XPRAM) += xpram.o
|
|||
obj-$(CONFIG_DCSSBLK) += dcssblk.o
|
||||
|
||||
scm_block-objs := scm_drv.o scm_blk.o
|
||||
ifdef CONFIG_SCM_BLOCK_CLUSTER_WRITE
|
||||
scm_block-objs += scm_blk_cluster.o
|
||||
endif
|
||||
obj-$(CONFIG_SCM_BLOCK) += scm_block.o
|
||||
|
|
|
|||
|
|
@ -37,6 +37,7 @@ static void __scm_free_rq(struct scm_request *scmrq)
|
|||
|
||||
free_page((unsigned long) scmrq->aob);
|
||||
free_page((unsigned long) scmrq->aidaw);
|
||||
__scm_free_rq_cluster(scmrq);
|
||||
kfree(aobrq);
|
||||
}
|
||||
|
||||
|
|
@ -70,6 +71,12 @@ static int __scm_alloc_rq(void)
|
|||
__scm_free_rq(scmrq);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
if (__scm_alloc_rq_cluster(scmrq)) {
|
||||
__scm_free_rq(scmrq);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
INIT_LIST_HEAD(&scmrq->list);
|
||||
spin_lock_irq(&list_lock);
|
||||
list_add(&scmrq->list, &inactive_requests);
|
||||
|
|
@ -170,6 +177,7 @@ static inline void scm_request_init(struct scm_blk_dev *bdev,
|
|||
scmrq->bdev = bdev;
|
||||
scmrq->retries = 4;
|
||||
scmrq->error = 0;
|
||||
scm_request_cluster_init(scmrq);
|
||||
}
|
||||
|
||||
static void scm_ensure_queue_restart(struct scm_blk_dev *bdev)
|
||||
|
|
@ -181,17 +189,19 @@ static void scm_ensure_queue_restart(struct scm_blk_dev *bdev)
|
|||
blk_delay_queue(bdev->rq, SCM_QUEUE_DELAY);
|
||||
}
|
||||
|
||||
static void scm_request_requeue(struct scm_request *scmrq)
|
||||
void scm_request_requeue(struct scm_request *scmrq)
|
||||
{
|
||||
struct scm_blk_dev *bdev = scmrq->bdev;
|
||||
|
||||
scm_release_cluster(scmrq);
|
||||
blk_requeue_request(bdev->rq, scmrq->request);
|
||||
scm_request_done(scmrq);
|
||||
scm_ensure_queue_restart(bdev);
|
||||
}
|
||||
|
||||
static void scm_request_finish(struct scm_request *scmrq)
|
||||
void scm_request_finish(struct scm_request *scmrq)
|
||||
{
|
||||
scm_release_cluster(scmrq);
|
||||
blk_end_request_all(scmrq->request, scmrq->error);
|
||||
scm_request_done(scmrq);
|
||||
}
|
||||
|
|
@ -215,6 +225,16 @@ static void scm_blk_request(struct request_queue *rq)
|
|||
return;
|
||||
}
|
||||
scm_request_init(bdev, scmrq, req);
|
||||
if (!scm_reserve_cluster(scmrq)) {
|
||||
SCM_LOG(5, "cluster busy");
|
||||
scm_request_done(scmrq);
|
||||
return;
|
||||
}
|
||||
if (scm_need_cluster_request(scmrq)) {
|
||||
blk_start_request(req);
|
||||
scm_initiate_cluster_request(scmrq);
|
||||
return;
|
||||
}
|
||||
scm_request_prepare(scmrq);
|
||||
blk_start_request(req);
|
||||
|
||||
|
|
@ -282,6 +302,13 @@ static void scm_blk_tasklet(struct scm_blk_dev *bdev)
|
|||
spin_lock_irqsave(&bdev->lock, flags);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (scm_test_cluster_request(scmrq)) {
|
||||
scm_cluster_request_irq(scmrq);
|
||||
spin_lock_irqsave(&bdev->lock, flags);
|
||||
continue;
|
||||
}
|
||||
|
||||
scm_request_finish(scmrq);
|
||||
atomic_dec(&bdev->queued_reqs);
|
||||
spin_lock_irqsave(&bdev->lock, flags);
|
||||
|
|
@ -325,6 +352,7 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
|
|||
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);
|
||||
scm_blk_dev_cluster_setup(bdev);
|
||||
|
||||
bdev->gendisk = alloc_disk(SCM_NR_PARTS);
|
||||
if (!bdev->gendisk)
|
||||
|
|
@ -370,7 +398,10 @@ void scm_blk_dev_cleanup(struct scm_blk_dev *bdev)
|
|||
|
||||
static int __init scm_blk_init(void)
|
||||
{
|
||||
int ret;
|
||||
int ret = -EINVAL;
|
||||
|
||||
if (!scm_cluster_size_valid())
|
||||
goto out;
|
||||
|
||||
ret = register_blkdev(0, "scm");
|
||||
if (ret < 0)
|
||||
|
|
|
|||
|
|
@ -22,6 +22,9 @@ struct scm_blk_dev {
|
|||
spinlock_t lock; /* guard the rest of the blockdev */
|
||||
atomic_t queued_reqs;
|
||||
struct list_head finished_requests;
|
||||
#ifdef CONFIG_SCM_BLOCK_CLUSTER_WRITE
|
||||
struct list_head cluster_list;
|
||||
#endif
|
||||
};
|
||||
|
||||
struct scm_request {
|
||||
|
|
@ -32,6 +35,13 @@ struct scm_request {
|
|||
struct list_head list;
|
||||
u8 retries;
|
||||
int error;
|
||||
#ifdef CONFIG_SCM_BLOCK_CLUSTER_WRITE
|
||||
struct {
|
||||
enum {CLUSTER_NONE, CLUSTER_READ, CLUSTER_WRITE} state;
|
||||
struct list_head list;
|
||||
void **buf;
|
||||
} cluster;
|
||||
#endif
|
||||
};
|
||||
|
||||
#define to_aobrq(rq) container_of((void *) rq, struct aob_rq_header, data)
|
||||
|
|
@ -40,9 +50,37 @@ int scm_blk_dev_setup(struct scm_blk_dev *, struct scm_device *);
|
|||
void scm_blk_dev_cleanup(struct scm_blk_dev *);
|
||||
void scm_blk_irq(struct scm_device *, void *, int);
|
||||
|
||||
void scm_request_finish(struct scm_request *);
|
||||
void scm_request_requeue(struct scm_request *);
|
||||
|
||||
int scm_drv_init(void);
|
||||
void scm_drv_cleanup(void);
|
||||
|
||||
#ifdef CONFIG_SCM_BLOCK_CLUSTER_WRITE
|
||||
void __scm_free_rq_cluster(struct scm_request *);
|
||||
int __scm_alloc_rq_cluster(struct scm_request *);
|
||||
void scm_request_cluster_init(struct scm_request *);
|
||||
bool scm_reserve_cluster(struct scm_request *);
|
||||
void scm_release_cluster(struct scm_request *);
|
||||
void scm_blk_dev_cluster_setup(struct scm_blk_dev *);
|
||||
bool scm_need_cluster_request(struct scm_request *);
|
||||
void scm_initiate_cluster_request(struct scm_request *);
|
||||
void scm_cluster_request_irq(struct scm_request *);
|
||||
bool scm_test_cluster_request(struct scm_request *);
|
||||
bool scm_cluster_size_valid(void);
|
||||
#else
|
||||
#define __scm_free_rq_cluster(scmrq) {}
|
||||
#define __scm_alloc_rq_cluster(scmrq) 0
|
||||
#define scm_request_cluster_init(scmrq) {}
|
||||
#define scm_reserve_cluster(scmrq) true
|
||||
#define scm_release_cluster(scmrq) {}
|
||||
#define scm_blk_dev_cluster_setup(bdev) {}
|
||||
#define scm_need_cluster_request(scmrq) false
|
||||
#define scm_initiate_cluster_request(scmrq) {}
|
||||
#define scm_cluster_request_irq(scmrq) {}
|
||||
#define scm_test_cluster_request(scmrq) false
|
||||
#define scm_cluster_size_valid() true
|
||||
#endif
|
||||
|
||||
extern debug_info_t *scm_debug;
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,228 @@
|
|||
/*
|
||||
* 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 (scm_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)
|
||||
{
|
||||
return write_cluster_size == 0 || write_cluster_size == 32 ||
|
||||
write_cluster_size == 64 || write_cluster_size == 128;
|
||||
}
|
||||
Загрузка…
Ссылка в новой задаче