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PCI: Device driver reset notification

PATCH New Keith Busch 2 participants 3 messages May 2, 2014 – May 27, 2014

Subsystems (3)
Block layer PCI NVMe
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Keith Busch

author
#0 lore raw

PATCH v2 1/2 PCI: Device driver reset notification

Notifies a pci device driver when its device's access is about to be disabled for an impending reset attempt, then after the attempt completes and device access is restored.

Signed-off-by Keith Busch <keith.busch at intel.com>

---
v1 -> v2:

Call the reset notification in all cases before device access is disabled and after device access is restored.

 drivers/pci/pci.c   |   21 +++++++++++++++++++++
 include/linux/pci.h |    3 +++
 2 files changed, 24 insertions(+)
drivers/pci/pci.c +21 -0
index 7325d43..43d87b2 100644
@@ -3305,8 +3305,27 @@ static void pci_dev_unlock(struct pci_dev *dev)
 	pci_cfg_access_unlock(dev);
 }
 
+/**
+ * pci_reset_notify - notify device driver of reset
+ * @dev: device to be notified of reset
+ * @prepare: 'true' if device is about to be reset; 'false' if reset attempt
+ *           completed
+ *
+ * Must be called prior to device access being disabled and after device
+ * access is restored.
+ */
+static void pci_reset_notify(struct pci_dev *dev, bool prepare)
+{
+	const struct pci_error_handlers *err_handler =
+			dev->driver ? dev->driver->err_handler : NULL;
+	if (err_handler && err_handler->reset_notify)
+		err_handler->reset_notify(dev, prepare);
+}
+
 static void pci_dev_save_and_disable(struct pci_dev *dev)
 {
+	pci_reset_notify(dev, true);
+
 	/*
 	 * Wake-up device prior to save.  PM registers default to D0 after
 	 * reset and a simple register restore doesn't reliably return

@@ -3328,6 +3347,7 @@ static void pci_dev_save_and_disable(struct pci_dev *dev)
 static void pci_dev_restore(struct pci_dev *dev)
 {
 	pci_restore_state(dev);
+	pci_reset_notify(dev, false);
 }
 
 static int pci_dev_reset(struct pci_dev *dev, int probe)

@@ -3344,6 +3364,7 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)
 
 	return rc;
 }
+
 /**
  * __pci_reset_function - reset a PCI device function
  * @dev: PCI device to reset
include/linux/pci.h +3 -0
index aab57b4..31c4309 100644
@@ -603,6 +603,9 @@ struct pci_error_handlers {
 	/* PCI slot has been reset */
 	pci_ers_result_t (*slot_reset)(struct pci_dev *dev);
 
+	/* PCI function reset prepare or completed */
+	void (*reset_notify)(struct pci_dev *dev, bool prepare);
+
 	/* Device driver may resume normal operations */
 	void (*resume)(struct pci_dev *dev);
 };
Signature · 1 line
1.7.10.4
author
#1 lore raw

PATCH v2 2/2 NVMe: Implement PCI-e reset notification callback

Quiesce and shutdown the device prior to reset, then restart the device and resume IO after.

Signed-off-by Keith Busch <keith.busch at intel.com>

---
v1 -> v2:

fixed compile warning for wrong data type in function (int -> bool).

 drivers/block/nvme-core.c |   11 +++++++++++
 1 file changed, 11 insertions(+)
drivers/block/nvme-core.c +11 -0
index 7c64fa7..a842c71 100644
@@ -2775,6 +2775,16 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return result;
 }
 
+static void nvme_reset_notify(struct pci_dev *pdev, bool prepare)
+{
+       struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+       if (prepare)
+               nvme_dev_shutdown(dev);
+       else
+               nvme_dev_resume(dev);
+}
+
 static void nvme_shutdown(struct pci_dev *pdev)
 {
 	struct nvme_dev *dev = pci_get_drvdata(pdev);

@@ -2839,6 +2849,7 @@ static const struct pci_error_handlers nvme_err_handler = {
 	.link_reset	= nvme_link_reset,
 	.slot_reset	= nvme_slot_reset,
 	.resume		= nvme_error_resume,
+	.reset_notify	= nvme_reset_notify,
 };
 
 /* Move to pci_ids.h later */
Signature · 1 line
1.7.10.4
maintainer
#2 lore raw

PATCH v2 1/2 PCI: Device driver reset notification

In reply to Keith Busch
Quoted 5 lines · Keith Busch

Notifies a pci device driver when its device's access is about to be disabled for an impending reset attempt, then after the attempt completes and device access is restored.

Signed-off-by Keith Busch <keith.busch at intel.com>

I applied both of these to my pci/hotplug branch for v3.16. Let me know if you want me to drop the NVMe patch and have it go via another tree.

Bjorn

Quoted 75 lines

---
v1 -> v2:

Call the reset notification in all cases before device access is disabled and after device access is restored.

 drivers/pci/pci.c   |   21 +++++++++++++++++++++
 include/linux/pci.h |    3 +++
 2 files changed, 24 insertions(+)
drivers/pci/pci.c +21 -0
index 7325d43..43d87b2 100644
@@ -3305,8 +3305,27 @@ static void pci_dev_unlock(struct pci_dev *dev)
 	pci_cfg_access_unlock(dev);
 }
 
+/**
+ * pci_reset_notify - notify device driver of reset
+ * @dev: device to be notified of reset
+ * @prepare: 'true' if device is about to be reset; 'false' if reset attempt
+ *           completed
+ *
+ * Must be called prior to device access being disabled and after device
+ * access is restored.
+ */
+static void pci_reset_notify(struct pci_dev *dev, bool prepare)
+{
+	const struct pci_error_handlers *err_handler =
+			dev->driver ? dev->driver->err_handler : NULL;
+	if (err_handler && err_handler->reset_notify)
+		err_handler->reset_notify(dev, prepare);
+}
+
 static void pci_dev_save_and_disable(struct pci_dev *dev)
 {
+	pci_reset_notify(dev, true);
+
 	/*
 	 * Wake-up device prior to save.  PM registers default to D0 after
 	 * reset and a simple register restore doesn't reliably return

@@ -3328,6 +3347,7 @@ static void pci_dev_save_and_disable(struct pci_dev *dev)
 static void pci_dev_restore(struct pci_dev *dev)
 {
 	pci_restore_state(dev);
+	pci_reset_notify(dev, false);
 }
 
 static int pci_dev_reset(struct pci_dev *dev, int probe)

@@ -3344,6 +3364,7 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)
 
 	return rc;
 }
+
 /**
  * __pci_reset_function - reset a PCI device function
  * @dev: PCI device to reset
include/linux/pci.h +3 -0
index aab57b4..31c4309 100644
@@ -603,6 +603,9 @@ struct pci_error_handlers {
 	/* PCI slot has been reset */
 	pci_ers_result_t (*slot_reset)(struct pci_dev *dev);
 
+	/* PCI function reset prepare or completed */
+	void (*reset_notify)(struct pci_dev *dev, bool prepare);
+
 	/* Device driver may resume normal operations */
 	void (*resume)(struct pci_dev *dev);
 };
Signature · 1 line
1.7.10.4