From f30664e2c85c7804f07c636bbe99f35e0b2d4c76 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Tue, 28 Aug 2012 16:50:38 +0200 Subject: s390: add scm block driver Block device driver for Storage Class Memory (SCM). This driver provides a block device interface for each available SCM increment. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/block/Kconfig | 11 ++ drivers/s390/block/Makefile | 3 + drivers/s390/block/scm_blk.c | 414 +++++++++++++++++++++++++++++++++++++++++++ drivers/s390/block/scm_blk.h | 79 +++++++++ drivers/s390/block/scm_drv.c | 90 ++++++++++ 5 files changed, 597 insertions(+) create mode 100644 drivers/s390/block/scm_blk.c create mode 100644 drivers/s390/block/scm_blk.h create mode 100644 drivers/s390/block/scm_drv.c (limited to 'drivers/s390') diff --git a/drivers/s390/block/Kconfig b/drivers/s390/block/Kconfig index 8e477bb1f3f6..18178b64e89a 100644 --- a/drivers/s390/block/Kconfig +++ b/drivers/s390/block/Kconfig @@ -70,3 +70,14 @@ config DASD_EER This driver provides a character device interface to the DASD extended error reporting. This is only needed if you want to use applications written for the EER facility. + +config SCM_BLOCK + def_tristate m + prompt "Support for Storage Class Memory" + depends on S390 && BLOCK && EADM_SCH && SCM_BUS + help + Block device driver for Storage Class Memory (SCM). This driver + provides a block device interface for each available SCM increment. + + To compile this driver as a module, choose M here: the + module will be called scm_block. diff --git a/drivers/s390/block/Makefile b/drivers/s390/block/Makefile index 0a89e080b389..b64e2b32c753 100644 --- a/drivers/s390/block/Makefile +++ b/drivers/s390/block/Makefile @@ -17,3 +17,6 @@ obj-$(CONFIG_DASD_ECKD) += dasd_eckd_mod.o obj-$(CONFIG_DASD_FBA) += dasd_fba_mod.o obj-$(CONFIG_BLK_DEV_XPRAM) += xpram.o obj-$(CONFIG_DCSSBLK) += dcssblk.o + +scm_block-objs := scm_drv.o scm_blk.o +obj-$(CONFIG_SCM_BLOCK) += scm_block.o diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c new file mode 100644 index 000000000000..634ad58cbef6 --- /dev/null +++ b/drivers/s390/block/scm_blk.c @@ -0,0 +1,414 @@ +/* + * Block driver for s390 storage class memory. + * + * Copyright IBM Corp. 2012 + * Author(s): Sebastian Ott + */ + +#define KMSG_COMPONENT "scm_block" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include "scm_blk.h" + +debug_info_t *scm_debug; +static int scm_major; +static DEFINE_SPINLOCK(list_lock); +static LIST_HEAD(inactive_requests); +static unsigned int nr_requests = 64; +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_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); + free_page((unsigned long) scmrq->aidaw); + 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); +} + +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->aidaw = (void *) get_zeroed_page(GFP_DMA); + scmrq->aob = (void *) get_zeroed_page(GFP_DMA); + if (!scmrq->aob || !scmrq->aidaw) { + __scm_free_rq(scmrq); + return -ENOMEM; + } + INIT_LIST_HEAD(&scmrq->list); + spin_lock_irq(&list_lock); + list_add(&scmrq->list, &inactive_requests); + spin_unlock_irq(&list_lock); + + return 0; +} + +static int scm_alloc_rqs(unsigned int nrqs) +{ + int ret = 0; + + while (nrqs-- && !ret) + ret = __scm_alloc_rq(); + + return ret; +} + +static struct scm_request *scm_request_fetch(void) +{ + struct scm_request *scmrq = NULL; + + spin_lock(&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(&list_lock); + return scmrq; +} + +static void scm_request_done(struct scm_request *scmrq) +{ + unsigned long flags; + + spin_lock_irqsave(&list_lock, flags); + list_add(&scmrq->list, &inactive_requests); + spin_unlock_irqrestore(&list_lock, flags); +} + +static int scm_open(struct block_device *blkdev, fmode_t mode) +{ + return scm_get_ref(); +} + +static int scm_release(struct gendisk *gendisk, fmode_t mode) +{ + scm_put_ref(); + return 0; +} + +static const struct block_device_operations scm_blk_devops = { + .owner = THIS_MODULE, + .open = scm_open, + .release = scm_release, +}; + +static void scm_request_prepare(struct scm_request *scmrq) +{ + struct scm_blk_dev *bdev = scmrq->bdev; + struct scm_device *scmdev = bdev->gendisk->private_data; + struct aidaw *aidaw = scmrq->aidaw; + struct msb *msb = &scmrq->aob->msb[0]; + struct req_iterator iter; + struct bio_vec *bv; + + msb->bs = MSB_BS_4K; + scmrq->aob->request.msb_count = 1; + msb->scm_addr = scmdev->address + + ((u64) blk_rq_pos(scmrq->request) << 9); + msb->oc = (rq_data_dir(scmrq->request) == READ) ? + MSB_OC_READ : MSB_OC_WRITE; + msb->flags |= MSB_FLAG_IDA; + msb->data_addr = (u64) aidaw; + + rq_for_each_segment(bv, scmrq->request, iter) { + WARN_ON(bv->bv_offset); + msb->blk_count += bv->bv_len >> 12; + aidaw->data_addr = (u64) page_address(bv->bv_page); + aidaw++; + } +} + +static inline void scm_request_init(struct scm_blk_dev *bdev, + struct scm_request *scmrq, + struct request *req) +{ + struct aob_rq_header *aobrq = to_aobrq(scmrq); + struct aob *aob = scmrq->aob; + + memset(aob, 0, sizeof(*aob)); + memset(scmrq->aidaw, 0, PAGE_SIZE); + aobrq->scmdev = bdev->scmdev; + aob->request.cmd_code = ARQB_CMD_MOVE; + aob->request.data = (u64) aobrq; + scmrq->request = req; + scmrq->bdev = bdev; + scmrq->retries = 4; + scmrq->error = 0; +} + +static void scm_ensure_queue_restart(struct scm_blk_dev *bdev) +{ + if (atomic_read(&bdev->queued_reqs)) { + /* Queue restart is triggered by the next interrupt. */ + return; + } + blk_delay_queue(bdev->rq, SCM_QUEUE_DELAY); +} + +static void scm_request_requeue(struct scm_request *scmrq) +{ + struct scm_blk_dev *bdev = scmrq->bdev; + + 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) +{ + blk_end_request_all(scmrq->request, scmrq->error); + scm_request_done(scmrq); +} + +static void scm_blk_request(struct request_queue *rq) +{ + struct scm_device *scmdev = rq->queuedata; + struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev); + struct scm_request *scmrq; + struct request *req; + int ret; + + while ((req = blk_peek_request(rq))) { + if (req->cmd_type != REQ_TYPE_FS) + continue; + + scmrq = scm_request_fetch(); + if (!scmrq) { + SCM_LOG(5, "no request"); + scm_ensure_queue_restart(bdev); + return; + } + scm_request_init(bdev, scmrq, req); + scm_request_prepare(scmrq); + blk_start_request(req); + + ret = scm_start_aob(scmrq->aob); + if (ret) { + SCM_LOG(5, "no subchannel"); + scm_request_requeue(scmrq); + return; + } + atomic_inc(&bdev->queued_reqs); + } +} + +static void __scmrq_log_error(struct scm_request *scmrq) +{ + struct aob *aob = scmrq->aob; + + if (scmrq->error == -ETIMEDOUT) + 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); +} + +void scm_blk_irq(struct scm_device *scmdev, void *data, int error) +{ + struct scm_request *scmrq = data; + struct scm_blk_dev *bdev = scmrq->bdev; + + scmrq->error = error; + if (error) + __scmrq_log_error(scmrq); + + spin_lock(&bdev->lock); + list_add_tail(&scmrq->list, &bdev->finished_requests); + spin_unlock(&bdev->lock); + tasklet_hi_schedule(&bdev->tasklet); +} + +static void scm_blk_tasklet(struct scm_blk_dev *bdev) +{ + struct scm_request *scmrq; + unsigned long flags; + + spin_lock_irqsave(&bdev->lock, flags); + while (!list_empty(&bdev->finished_requests)) { + scmrq = list_first_entry(&bdev->finished_requests, + struct scm_request, list); + list_del(&scmrq->list); + spin_unlock_irqrestore(&bdev->lock, flags); + + if (scmrq->error && scmrq->retries-- > 0) { + if (scm_start_aob(scmrq->aob)) { + spin_lock_irqsave(&bdev->rq_lock, flags); + scm_request_requeue(scmrq); + spin_unlock_irqrestore(&bdev->rq_lock, flags); + } + /* Request restarted or requeued, handle next. */ + spin_lock_irqsave(&bdev->lock, flags); + continue; + } + scm_request_finish(scmrq); + atomic_dec(&bdev->queued_reqs); + spin_lock_irqsave(&bdev->lock, flags); + } + spin_unlock_irqrestore(&bdev->lock, flags); + /* Look out for more requests. */ + blk_run_queue(bdev->rq); +} + +int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev) +{ + struct request_queue *rq; + int len, ret = -ENOMEM; + unsigned int devindex, nr_max_blk; + + devindex = atomic_inc_return(&nr_devices) - 1; + /* scma..scmz + scmaa..scmzz */ + if (devindex > 701) { + ret = -ENODEV; + goto out; + } + + bdev->scmdev = scmdev; + spin_lock_init(&bdev->rq_lock); + spin_lock_init(&bdev->lock); + INIT_LIST_HEAD(&bdev->finished_requests); + atomic_set(&bdev->queued_reqs, 0); + tasklet_init(&bdev->tasklet, + (void (*)(unsigned long)) scm_blk_tasklet, + (unsigned long) bdev); + + rq = blk_init_queue(scm_blk_request, &bdev->rq_lock); + if (!rq) + goto out; + + 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); + + bdev->gendisk = alloc_disk(SCM_NR_PARTS); + if (!bdev->gendisk) + goto out_queue; + + rq->queuedata = scmdev; + bdev->gendisk->driverfs_dev = &scmdev->dev; + 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); + add_disk(bdev->gendisk); + return 0; + +out_queue: + blk_cleanup_queue(rq); +out: + atomic_dec(&nr_devices); + return ret; +} + +void scm_blk_dev_cleanup(struct scm_blk_dev *bdev) +{ + tasklet_kill(&bdev->tasklet); + del_gendisk(bdev->gendisk); + blk_cleanup_queue(bdev->gendisk->queue); + put_disk(bdev->gendisk); +} + +static int __init scm_blk_init(void) +{ + int ret; + + ret = register_blkdev(0, "scm"); + if (ret < 0) + goto out; + + scm_major = ret; + if (scm_alloc_rqs(nr_requests)) + goto out_unreg; + + scm_debug = debug_register("scm_log", 16, 1, 16); + if (!scm_debug) + 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(); +out_unreg: + 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); diff --git a/drivers/s390/block/scm_blk.h b/drivers/s390/block/scm_blk.h new file mode 100644 index 000000000000..5aba5612588f --- /dev/null +++ b/drivers/s390/block/scm_blk.h @@ -0,0 +1,79 @@ +#ifndef SCM_BLK_H +#define SCM_BLK_H + +#include +#include +#include +#include +#include + +#include +#include + +#define SCM_NR_PARTS 8 +#define SCM_QUEUE_DELAY 5 + +struct scm_blk_dev { + struct tasklet_struct tasklet; + struct request_queue *rq; + struct gendisk *gendisk; + struct scm_device *scmdev; + spinlock_t rq_lock; /* guard the request queue */ + spinlock_t lock; /* guard the rest of the blockdev */ + atomic_t queued_reqs; + struct list_head finished_requests; +}; + +struct scm_request { + struct scm_blk_dev *bdev; + struct request *request; + struct aidaw *aidaw; + struct aob *aob; + struct list_head list; + u8 retries; + int error; +}; + +#define to_aobrq(rq) container_of((void *) rq, struct aob_rq_header, data) + +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); + +int scm_drv_init(void); +void scm_drv_cleanup(void); + + +extern debug_info_t *scm_debug; + +#define SCM_LOG(imp, txt) do { \ + debug_text_event(scm_debug, imp, txt); \ + } while (0) + +static inline void SCM_LOG_HEX(int level, void *data, int length) +{ + if (level > scm_debug->level) + return; + while (length > 0) { + debug_event(scm_debug, level, data, length); + length -= scm_debug->buf_size; + data += scm_debug->buf_size; + } +} + +static inline void SCM_LOG_STATE(int level, struct scm_device *scmdev) +{ + struct { + u64 address; + u8 oper_state; + u8 rank; + } __packed data = { + .address = scmdev->address, + .oper_state = scmdev->attrs.oper_state, + .rank = scmdev->attrs.rank, + }; + + SCM_LOG_HEX(level, &data, sizeof(data)); +} + +#endif /* SCM_BLK_H */ diff --git a/drivers/s390/block/scm_drv.c b/drivers/s390/block/scm_drv.c new file mode 100644 index 000000000000..fce711a63060 --- /dev/null +++ b/drivers/s390/block/scm_drv.c @@ -0,0 +1,90 @@ +/* + * Device driver for s390 storage class memory. + * + * Copyright IBM Corp. 2012 + * Author(s): Sebastian Ott + */ + +#define KMSG_COMPONENT "scm_block" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include +#include +#include +#include +#include "scm_blk.h" + +static void notify(struct scm_device *scmdev) +{ + pr_info("%lu: The capabilities of the SCM increment changed\n", + (unsigned long) scmdev->address); + SCM_LOG(2, "State changed"); + SCM_LOG_STATE(2, scmdev); +} + +static int scm_probe(struct scm_device *scmdev) +{ + struct scm_blk_dev *bdev; + int ret; + + SCM_LOG(2, "probe"); + SCM_LOG_STATE(2, scmdev); + + if (scmdev->attrs.oper_state != OP_STATE_GOOD) + return -EINVAL; + + bdev = kzalloc(sizeof(*bdev), GFP_KERNEL); + if (!bdev) + return -ENOMEM; + + spin_lock_irq(&scmdev->lock); + dev_set_drvdata(&scmdev->dev, bdev); + spin_unlock_irq(&scmdev->lock); + + ret = scm_blk_dev_setup(bdev, scmdev); + if (ret) { + spin_lock_irq(&scmdev->lock); + dev_set_drvdata(&scmdev->dev, NULL); + spin_unlock_irq(&scmdev->lock); + kfree(bdev); + goto out; + } + +out: + return ret; +} + +static int scm_remove(struct scm_device *scmdev) +{ + struct scm_blk_dev *bdev; + + spin_lock_irq(&scmdev->lock); + bdev = dev_get_drvdata(&scmdev->dev); + dev_set_drvdata(&scmdev->dev, NULL); + spin_unlock_irq(&scmdev->lock); + scm_blk_dev_cleanup(bdev); + kfree(bdev); + + return 0; +} + +static struct scm_driver scm_drv = { + .drv = { + .name = "scm_block", + .owner = THIS_MODULE, + }, + .notify = notify, + .probe = scm_probe, + .remove = scm_remove, + .handler = scm_blk_irq, +}; + +int __init scm_drv_init(void) +{ + return scm_driver_register(&scm_drv); +} + +void scm_drv_cleanup(void) +{ + scm_driver_unregister(&scm_drv); +} -- cgit v1.2.3