[PATCH 5/5] nvme: Add two-pass shutdown support.
Jeremy Allison
jallison at ciq.com
Mon Jan 29 10:19:53 PST 2024
This works with the two-pass shutdown mechanism setup for the PCI
drivers and participates to provide the shutdown_wait
method at the pci_driver structure level.
This patch changes the nvme shutdown() method to pass
down the NVME_PCI_DISABLE_SHUTDOWN_TWOPASS enum value instead
of NVME_PCI_DISABLE_SHUTDOWN. nvme_dev_disable() is changed
to call nvme_request_shutdown() instead of nvme_disable_ctrl()
in this case.
nvme_request_shutdown() sets the shutdown bit,
but does not wait for completion.
The nvme_shutdown_wait() callback is added to synchronously
wait for the NVME_CSTS_SHST_CMPLT bit meaning the nvme
device has shutdown.
This change speeds up the shutdown in a system which hosts
many controllers.
Based on work by Tanjore Suresh <tansuresh at google.com>
Signed-off-by: Jeremy Allison <jallison at ciq.com>
---
drivers/nvme/host/pci.c | 39 ++++++++++++++++++++++++++++++++++++---
1 file changed, 36 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 8ee77f755d9d..bbd89eecf05a 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2607,7 +2607,14 @@ static void nvme_dev_disable(struct nvme_dev *dev,
if (!dead && dev->ctrl.queue_count > 0) {
nvme_delete_io_queues(dev);
- nvme_disable_ctrl(&dev->ctrl, shutdown);
+ /*
+ * NVME_PCI_DISABLE_SHUTDOWN_TWOPASS requests shutdown
+ * but doesn't wait for completion.
+ */
+ if (shutdown_type == NVME_PCI_DISABLE_SHUTDOWN_TWOPASS)
+ nvme_request_shutdown(&dev->ctrl);
+ else
+ nvme_disable_ctrl(&dev->ctrl, shutdown);
nvme_poll_irqdisable(&dev->queues[0]);
}
nvme_suspend_io_queues(dev);
@@ -2625,7 +2632,7 @@ static void nvme_dev_disable(struct nvme_dev *dev,
* must flush all entered requests to their failed completion to avoid
* deadlocking blk-mq hot-cpu notifier.
*/
- if (shutdown) {
+ if (shutdown_type == NVME_PCI_DISABLE_SHUTDOWN) {
nvme_unquiesce_io_queues(&dev->ctrl);
if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q))
nvme_unquiesce_admin_queue(&dev->ctrl);
@@ -3128,7 +3135,32 @@ static void nvme_shutdown(struct pci_dev *pdev)
{
struct nvme_dev *dev = pci_get_drvdata(pdev);
- nvme_disable_prepare_reset(dev, NVME_PCI_DISABLE_SHUTDOWN);
+ nvme_disable_prepare_reset(dev, NVME_PCI_DISABLE_SHUTDOWN_TWOPASS);
+}
+
+static void nvme_shutdown_wait(struct pci_dev *pdev)
+{
+ struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+ mutex_lock(&dev->shutdown_lock);
+ /*
+ * Finish waiting for the shutdown request
+ * initiated in nvme_shutdown() above using
+ * NVME_PCI_DISABLE_SHUTDOWN_TWOPASS.
+ */
+ nvme_wait_ready(&dev->ctrl, NVME_CSTS_SHST_MASK,
+ NVME_CSTS_SHST_CMPLT,
+ dev->ctrl.shutdown_timeout, "shutdown");
+ /*
+ * The driver will not be starting up queues again if shutting down so
+ * must flush all entered requests to their failed completion to avoid
+ * deadlocking blk-mq hot-cpu notifier.
+ */
+ nvme_unquiesce_io_queues(&dev->ctrl);
+ if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q))
+ nvme_unquiesce_admin_queue(&dev->ctrl);
+
+ mutex_unlock(&dev->shutdown_lock);
}
/*
@@ -3522,6 +3554,7 @@ static struct pci_driver nvme_driver = {
.probe = nvme_probe,
.remove = nvme_remove,
.shutdown = nvme_shutdown,
+ .shutdown_wait = nvme_shutdown_wait,
.driver = {
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
#ifdef CONFIG_PM_SLEEP
--
2.39.3
More information about the Linux-nvme
mailing list