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authorMatthew Wilcox <matthew.r.wilcox@intel.com>2011-10-20 17:00:41 -0400
committerMatthew Wilcox <matthew.r.wilcox@intel.com>2011-11-04 15:53:05 -0400
commitf1938f6e1ee1583c87ec74dc406fdd8694e99ac8 (patch)
treea1e27b0feb844ac675ba90230e8411dce7a86f71 /drivers
parentce38c149576fd0a3360fec3bef4012212d42e736 (diff)
NVMe: Implement doorbell stride capability
The doorbell stride allows devices to spread out their doorbells instead of packing them tightly. This feature was added as part of ECN 003. This patch also enables support for more than 512 queues :-) Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/nvme.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index cfe5932821d8..a17f80fa3881 100644
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -70,6 +70,7 @@ struct nvme_dev {
struct dma_pool *prp_small_pool;
int instance;
int queue_count;
+ int db_stride;
u32 ctrl_config;
struct msix_entry *entry;
struct nvme_bar __iomem *bar;
@@ -672,7 +673,7 @@ static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
return IRQ_NONE;
- writel(head, nvmeq->q_db + 1);
+ writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
nvmeq->cq_head = head;
nvmeq->cq_phase = phase;
@@ -889,7 +890,7 @@ 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 * 2];
+ nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
nvmeq->q_depth = depth;
nvmeq->cq_vector = vector;
@@ -981,6 +982,7 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
cap = readq(&dev->bar->cap);
timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
+ dev->db_stride = NVME_CAP_STRIDE(cap);
while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
msleep(100);
@@ -1357,7 +1359,7 @@ static int set_queue_count(struct nvme_dev *dev, int count)
static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
{
- int result, cpu, i, nr_io_queues;
+ int result, cpu, i, nr_io_queues, db_bar_size;
nr_io_queues = num_online_cpus();
result = set_queue_count(dev, nr_io_queues);
@@ -1369,6 +1371,15 @@ static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
/* Deregister the admin queue's interrupt */
free_irq(dev->entry[0].vector, dev->queues[0]);
+ db_bar_size = 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3));
+ if (db_bar_size > 8192) {
+ iounmap(dev->bar);
+ dev->bar = ioremap(pci_resource_start(dev->pci_dev, 0),
+ db_bar_size);
+ dev->dbs = ((void __iomem *)dev->bar) + 4096;
+ dev->queues[0]->q_db = dev->dbs;
+ }
+
for (i = 0; i < nr_io_queues; i++)
dev->entry[i].entry = i;
for (;;) {