From bb8d261e088811ef2b564d745afcd1633428010a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 26 Apr 2016 13:51:57 +0200 Subject: [PATCH] nvme: introduce a controller state machine Replace the adhoc flags in the PCI driver with a state machine in the core code. Based on code from Sagi Grimberg for the Fabrics driver. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Acked-by Jon Derrick: Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 51 ++++++++++++++++++++++++++++++++++++++++ drivers/nvme/host/nvme.h | 11 +++++++++ drivers/nvme/host/pci.c | 25 ++++++++++---------- 3 files changed, 74 insertions(+), 13 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 20559ad98be1..bd8f598d0c37 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -58,6 +58,55 @@ static DEFINE_SPINLOCK(dev_list_lock); static struct class *nvme_class; +bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, + enum nvme_ctrl_state new_state) +{ + enum nvme_ctrl_state old_state = ctrl->state; + bool changed = false; + + spin_lock_irq(&ctrl->lock); + switch (new_state) { + case NVME_CTRL_LIVE: + switch (old_state) { + case NVME_CTRL_RESETTING: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case NVME_CTRL_RESETTING: + switch (old_state) { + case NVME_CTRL_NEW: + case NVME_CTRL_LIVE: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + case NVME_CTRL_DELETING: + switch (old_state) { + case NVME_CTRL_LIVE: + case NVME_CTRL_RESETTING: + changed = true; + /* FALLTHRU */ + default: + break; + } + break; + default: + break; + } + spin_unlock_irq(&ctrl->lock); + + if (changed) + ctrl->state = new_state; + + return changed; +} +EXPORT_SYMBOL_GPL(nvme_change_ctrl_state); + static void nvme_free_ns(struct kref *kref) { struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref); @@ -1583,6 +1632,8 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, { int ret; + ctrl->state = NVME_CTRL_NEW; + spin_lock_init(&ctrl->lock); INIT_LIST_HEAD(&ctrl->namespaces); mutex_init(&ctrl->namespaces_mutex); kref_init(&ctrl->kref); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 41e922b33f11..4135626a3d6f 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -67,7 +67,16 @@ enum nvme_quirks { NVME_QUIRK_DISCARD_ZEROES = (1 << 2), }; +enum nvme_ctrl_state { + NVME_CTRL_NEW, + NVME_CTRL_LIVE, + NVME_CTRL_RESETTING, + NVME_CTRL_DELETING, +}; + struct nvme_ctrl { + enum nvme_ctrl_state state; + spinlock_t lock; const struct nvme_ctrl_ops *ops; struct request_queue *admin_q; struct device *dev; @@ -187,6 +196,8 @@ static inline bool nvme_req_needs_retry(struct request *req, u16 status) (jiffies - req->start_time) < req->timeout; } +bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, + enum nvme_ctrl_state new_state); int nvme_disable_ctrl(struct nvme_ctrl *ctrl, u64 cap); int nvme_enable_ctrl(struct nvme_ctrl *ctrl, u64 cap); int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl); diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 321b8e03843a..0cee23651aa7 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -102,11 +102,6 @@ struct nvme_dev { dma_addr_t cmb_dma_addr; u64 cmb_size; u32 cmbsz; - unsigned long flags; - -#define NVME_CTRL_RESETTING 0 -#define NVME_CTRL_REMOVING 1 - struct nvme_ctrl ctrl; struct completion ioq_wait; }; @@ -277,9 +272,8 @@ static void nvme_queue_scan(struct nvme_dev *dev) * Do not queue new scan work when a controller is reset during * removal. */ - if (test_bit(NVME_CTRL_REMOVING, &dev->flags)) - return; - queue_work(nvme_workq, &dev->scan_work); + if (dev->ctrl.state != NVME_CTRL_DELETING) + queue_work(nvme_workq, &dev->scan_work); } static void nvme_complete_async_event(struct nvme_dev *dev, @@ -901,7 +895,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved) * cancellation error. All outstanding requests are completed on * shutdown, so we return BLK_EH_HANDLED. */ - if (test_bit(NVME_CTRL_RESETTING, &dev->flags)) { + if (dev->ctrl.state == NVME_CTRL_RESETTING) { dev_warn(dev->ctrl.device, "I/O %d QID %d timeout, disable controller\n", req->tag, nvmeq->qid); @@ -1835,7 +1829,7 @@ static void nvme_reset_work(struct work_struct *work) struct nvme_dev *dev = container_of(work, struct nvme_dev, reset_work); int result = -ENODEV; - if (WARN_ON(test_bit(NVME_CTRL_RESETTING, &dev->flags))) + if (WARN_ON(dev->ctrl.state == NVME_CTRL_RESETTING)) goto out; /* @@ -1845,7 +1839,8 @@ static void nvme_reset_work(struct work_struct *work) if (dev->ctrl.ctrl_config & NVME_CC_ENABLE) nvme_dev_disable(dev, false); - set_bit(NVME_CTRL_RESETTING, &dev->flags); + if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_RESETTING)) + goto out; result = nvme_pci_enable(dev); if (result) @@ -1894,7 +1889,10 @@ static void nvme_reset_work(struct work_struct *work) nvme_dev_add(dev); } - clear_bit(NVME_CTRL_RESETTING, &dev->flags); + if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_LIVE)) { + dev_warn(dev->ctrl.device, "failed to mark controller live\n"); + goto out; + } return; out: @@ -2067,7 +2065,8 @@ static void nvme_remove(struct pci_dev *pdev) del_timer_sync(&dev->watchdog_timer); - set_bit(NVME_CTRL_REMOVING, &dev->flags); + nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING); + pci_set_drvdata(pdev, NULL); flush_work(&dev->async_work); flush_work(&dev->scan_work); -- 2.39.5