nvme: split dev_list_lock

Split dev_list_lock into one in the core and one in the PCI driver.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/nvme/host/core.c

@@ -52,7 +52,7 @@ static int nvme_char_major;
 module_param(nvme_char_major, int, 0);
 
 static LIST_HEAD(nvme_ctrl_list);
-DEFINE_SPINLOCK(dev_list_lock);
+static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 

drivers/nvme/host/nvme.h

@@ -266,8 +266,6 @@ int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
 			dma_addr_t dma_addr, u32 *result);
 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count);
 
-extern spinlock_t dev_list_lock;
-
 struct sg_io_hdr;
 
 int nvme_sg_io(struct nvme_ns *ns, struct sg_io_hdr __user *u_hdr);

drivers/nvme/host/pci.c

@@ -65,6 +65,7 @@ module_param(use_cmb_sqes, bool, 0644);
 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
 
 static LIST_HEAD(dev_list);
+static DEFINE_SPINLOCK(dev_list_lock);
 static struct task_struct *nvme_thread;
 static struct workqueue_struct *nvme_workq;
 static wait_queue_head_t nvme_kthread_wait;