NVMe: Add nvme subsystem reset IOCTL

Controllers can perform optional subsystem resets as introduced in NVMe
1.1. This patch adds an IOCTL to trigger the subsystem reset by writing
"NVMe" to the NSSR register.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Jon Derrick 2015-08-10 15:20:41 -06:00 committed by Jens Axboe
parent dfbac8c7ac
commit 81f03fedcc
3 changed files with 13 additions and 1 deletions

View File

@ -1901,6 +1901,15 @@ static int nvme_user_cmd(struct nvme_dev *dev, struct nvme_ns *ns,
return status;
}
static int nvme_subsys_reset(struct nvme_dev *dev)
{
if (!dev->subsystem)
return -ENOTTY;
writel(0x4E564D65, &dev->bar->nssr); /* "NVMe" */
return 0;
}
static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
unsigned long arg)
{
@ -2932,6 +2941,8 @@ static long nvme_dev_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
case NVME_IOCTL_RESET:
dev_warn(dev->dev, "resetting controller\n");
return nvme_reset(dev);
case NVME_IOCTL_SUBSYS_RESET:
return nvme_subsys_reset(dev);
default:
return -ENOTTY;
}

View File

@ -28,7 +28,7 @@ struct nvme_bar {
__u32 cc; /* Controller Configuration */
__u32 rsvd1; /* Reserved */
__u32 csts; /* Controller Status */
__u32 rsvd2; /* Reserved */
__u32 nssr; /* Subsystem Reset */
__u32 aqa; /* Admin Queue Attributes */
__u64 asq; /* Admin SQ Base Address */
__u64 acq; /* Admin CQ Base Address */

View File

@ -584,5 +584,6 @@ struct nvme_passthru_cmd {
#define NVME_IOCTL_SUBMIT_IO _IOW('N', 0x42, struct nvme_user_io)
#define NVME_IOCTL_IO_CMD _IOWR('N', 0x43, struct nvme_passthru_cmd)
#define NVME_IOCTL_RESET _IO('N', 0x44)
#define NVME_IOCTL_SUBSYS_RESET _IO('N', 0x45)
#endif /* _UAPI_LINUX_NVME_H */