diff options
| author | Haiyan Hu <huhaiyan@huawei.com> | 2013-09-10 11:25:37 +0800 |
|---|---|---|
| committer | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2013-11-18 17:10:51 -0500 |
| commit | b80d5ccca3a012e91ca64a2a0b13049163a6a698 (patch) | |
| tree | 97d64d8d70ecc42f04ee52023c636d84c05e7a21 | |
| parent | 2d3c627502f2a9b0a7de06a5a2df2365542a72c9 (diff) | |
NVMe: Avoid shift operation when writing cq head doorbell
Changes the type of dev->db_stride to unsigned and changes the value
stored there to be 1 << the current value. Then there is less
calculation to be done at completion time.
Signed-off-by: Haiyan Hu <huhaiyan@huawei.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
| -rw-r--r-- | drivers/block/nvme-core.c | 10 | ||||
| -rw-r--r-- | include/linux/nvme.h | 2 |
2 files changed, 6 insertions, 6 deletions
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 26d03fa0bf2..073aec913c7 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -775,7 +775,7 @@ static int nvme_process_cq(struct nvme_queue *nvmeq) if (head == nvmeq->cq_head && phase == nvmeq->cq_phase) return 0; - writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride)); + writel(head, nvmeq->q_db + nvmeq->dev->db_stride); nvmeq->cq_head = head; nvmeq->cq_phase = phase; @@ -1113,7 +1113,7 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid, init_waitqueue_head(&nvmeq->sq_full); init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread); bio_list_init(&nvmeq->sq_cong); - nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)]; + nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride]; nvmeq->q_depth = depth; nvmeq->cq_vector = vector; nvmeq->q_suspended = 1; @@ -1149,7 +1149,7 @@ static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid) nvmeq->sq_tail = 0; nvmeq->cq_head = 0; nvmeq->cq_phase = 1; - nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)]; + nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride]; memset(nvmeq->cmdid_data, 0, extra); memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth)); nvme_cancel_ios(nvmeq, false); @@ -1741,7 +1741,7 @@ static int set_queue_count(struct nvme_dev *dev, int count) static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues) { - return 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3)); + return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride); } static int nvme_setup_io_queues(struct nvme_dev *dev) @@ -1958,7 +1958,7 @@ static int nvme_dev_map(struct nvme_dev *dev) if (!dev->bar) goto disable; - dev->db_stride = NVME_CAP_STRIDE(readq(&dev->bar->cap)); + dev->db_stride = 1 << NVME_CAP_STRIDE(readq(&dev->bar->cap)); dev->dbs = ((void __iomem *)dev->bar) + 4096; return 0; diff --git a/include/linux/nvme.h b/include/linux/nvme.h index 26ebcf41c21..8119a476cb2 100644 --- a/include/linux/nvme.h +++ b/include/linux/nvme.h @@ -80,7 +80,7 @@ struct nvme_dev { struct dma_pool *prp_small_pool; int instance; int queue_count; - int db_stride; + u32 db_stride; u32 ctrl_config; struct msix_entry *entry; struct nvme_bar __iomem *bar; |