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Release 4.11 drivers/s390/block/scm_blk_cluster.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); }

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Sebastian Ott63100.00%1100.00%
Total63100.00%1100.00%


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; }

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Sebastian Ott111100.00%1100.00%
Total111100.00%1100.00%


void scm_request_cluster_init(struct scm_request *scmrq) { scmrq->cluster.state = CLUSTER_NONE; }

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Sebastian Ott18100.00%1100.00%
Total18100.00%1100.00%


static bool clusters_intersect(struct request *A, struct request *B) { unsigned long firstA, lastA, firstB, lastB; firstA = ((u64) blk_rq_pos(A) << 9) / CLUSTER_SIZE; lastA = (((u64) blk_rq_pos(A) << 9) + blk_rq_bytes(A) - 1) / CLUSTER_SIZE; firstB = ((u64) blk_rq_pos(B) << 9) / CLUSTER_SIZE; lastB = (((u64) blk_rq_pos(B) << 9) + blk_rq_bytes(B) - 1) / CLUSTER_SIZE; return (firstB <= lastA && firstA <= lastB); }

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Sebastian Ott119100.00%2100.00%
Total119100.00%2100.00%


bool scm_reserve_cluster(struct scm_request *scmrq) { struct request *req = scmrq->request[scmrq->aob->request.msb_count]; struct scm_blk_dev *bdev = scmrq->bdev; struct scm_request *iter; int pos, add = 1; if (write_cluster_size == 0) return true; spin_lock(&bdev->lock); list_for_each_entry(iter, &bdev->cluster_list, cluster.list) { if (iter == scmrq) { /* * We don't have to use clusters_intersect here, since * cluster requests are always started separately. */ add = 0; continue; } for (pos = 0; pos < iter->aob->request.msb_count; pos++) { if (clusters_intersect(req, iter->request[pos]) && (rq_data_dir(req) == WRITE || rq_data_dir(iter->request[pos]) == WRITE)) { spin_unlock(&bdev->lock); return false; } } } if (add) list_add(&scmrq->cluster.list, &bdev->cluster_list); spin_unlock(&bdev->lock); return true; }

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Sebastian Ott189100.00%3100.00%
Total189100.00%3100.00%


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); }

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Sebastian Ott60100.00%1100.00%
Total60100.00%1100.00%


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); }

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Sebastian Ott27100.00%1100.00%
Total27100.00%1100.00%


static int 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[0]; struct msb *msb = &scmrq->aob->msb[0]; struct req_iterator iter; struct aidaw *aidaw; 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: msb->bs = MSB_BS_4K; msb->oc = MSB_OC_READ; msb->flags = MSB_FLAG_IDA; 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; aidaw = scm_aidaw_fetch(scmrq, msb->blk_count * PAGE_SIZE); if (!aidaw) return -ENOMEM; scmrq->aob->request.msb_count = 1; msb->data_addr = (u64) aidaw; for (i = 0; i < msb->blk_count; i++) { aidaw->data_addr = (u64) scmrq->cluster.buf[i]; aidaw++; } break; case CLUSTER_WRITE: aidaw = (void *) msb->data_addr; 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; } return 0; }

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Sebastian Ott40599.75%480.00%
Kent Overstreet10.25%120.00%
Total406100.00%5100.00%


bool scm_need_cluster_request(struct scm_request *scmrq) { int pos = scmrq->aob->request.msb_count; if (rq_data_dir(scmrq->request[pos]) == READ) return false; return blk_rq_bytes(scmrq->request[pos]) < CLUSTER_SIZE; }

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Sebastian Ott51100.00%2100.00%
Total51100.00%2100.00%

/* Called with queue lock held. */
void scm_initiate_cluster_request(struct scm_request *scmrq) { if (scm_prepare_cluster_request(scmrq)) goto requeue; if (eadm_start_aob(scmrq->aob)) goto requeue; return; requeue: scm_request_requeue(scmrq); }

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Sebastian Ott40100.00%3100.00%
Total40100.00%3100.00%


bool scm_test_cluster_request(struct scm_request *scmrq) { return scmrq->cluster.state != CLUSTER_NONE; }

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Sebastian Ott19100.00%1100.00%
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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; } }

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Sebastian Ott100100.00%1100.00%
Total100100.00%1100.00%


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)); }

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Sebastian Ott32100.00%2100.00%
Total32100.00%2100.00%


Overall Contributors

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Sebastian Ott128799.92%787.50%
Kent Overstreet10.08%112.50%
Total1288100.00%8100.00%
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