[PATCH 10/14] NVMe: Factor out nvme_set_queue_count()

From: Alexander Gordeev
Date: Tue Jan 28 2014 - 04:44:07 EST


Function nvme_setup_io_queues() is quite big - make it more
readable by moving out a code with clearly distinguishable
functionality. This update is the first in a series.

Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
---
drivers/block/nvme-core.c | 28 +++++++++++++++++-----------
1 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 1821091..d81b4c4 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1875,22 +1875,21 @@ static int set_queue_count(struct nvme_dev *dev, int count)
return min(result & 0xffff, result >> 16) + 1;
}

+static int nvme_set_queue_count(struct nvme_dev *dev, int count)
+{
+ int result = set_queue_count(dev, count);
+ return min(result, count);
+}
+
static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
{
return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
}

-static int nvme_setup_io_queues(struct nvme_dev *dev)
+static int nvme_setup_io_queues(struct nvme_dev *dev, int nr_io_queues)
{
struct pci_dev *pdev = dev->pci_dev;
- int result, cpu, i, vecs, nr_io_queues, size, q_depth;
-
- nr_io_queues = num_online_cpus();
- result = set_queue_count(dev, nr_io_queues);
- if (result < 0)
- return result;
- if (result < nr_io_queues)
- nr_io_queues = result;
+ int result, cpu, i, vecs, size, q_depth;

size = db_bar_size(dev, nr_io_queues);
if (size > 8192) {
@@ -2417,13 +2416,20 @@ static int nvme_dev_start(struct nvme_dev *dev)
list_add(&dev->node, &dev_list);
spin_unlock(&dev_list_lock);

- result = nvme_setup_io_queues(dev);
- if (result && result != -EBUSY)
+ result = nvme_set_queue_count(dev, num_online_cpus());
+ if (result < 0)
+ goto disable;
+
+ result = nvme_setup_io_queues(dev, result);
+ if (result)
goto disable;

return 0;

disable:
+ if (result == -EBUSY)
+ return -EBUSY;
+
nvme_disable_queue(dev->queues[0]);
spin_lock(&dev_list_lock);
list_del_init(&dev->node);
--
1.7.7.6

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