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path: root/drivers/xen/xen-pciback/pci_stub.c
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Diffstat (limited to 'drivers/xen/xen-pciback/pci_stub.c')
-rw-r--r--drivers/xen/xen-pciback/pci_stub.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 62fcd485f0a7..d57a173685f3 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -242,6 +242,15 @@ struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
return found_dev;
}
+/*
+ * Called when:
+ * - XenBus state has been reconfigure (pci unplug). See xen_pcibk_remove_device
+ * - XenBus state has been disconnected (guest shutdown). See xen_pcibk_xenbus_remove
+ * - 'echo BDF > unbind' on pciback module with no guest attached. See pcistub_remove
+ * - 'echo BDF > unbind' with a guest still using it. See pcistub_remove
+ *
+ * As such we have to be careful.
+ */
void pcistub_put_pci_dev(struct pci_dev *dev)
{
struct pcistub_device *psdev, *found_psdev = NULL;
@@ -272,16 +281,16 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
* and want to inhibit the user from fiddling with 'reset'
*/
pci_reset_function(dev);
- pci_restore_state(psdev->dev);
+ pci_restore_state(dev);
/* This disables the device. */
- xen_pcibk_reset_device(found_psdev->dev);
+ xen_pcibk_reset_device(dev);
/* And cleanup up our emulated fields. */
- xen_pcibk_config_free_dyn_fields(found_psdev->dev);
- xen_pcibk_config_reset_dev(found_psdev->dev);
+ xen_pcibk_config_reset_dev(dev);
+ xen_pcibk_config_free_dyn_fields(dev);
- xen_unregister_device_domain_owner(found_psdev->dev);
+ xen_unregister_device_domain_owner(dev);
spin_lock_irqsave(&found_psdev->lock, flags);
found_psdev->pdev = NULL;
@@ -493,6 +502,8 @@ static int pcistub_seize(struct pci_dev *dev)
return err;
}
+/* Called when 'bind'. This means we must _NOT_ call pci_reset_function or
+ * other functions that take the sysfs lock. */
static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
int err = 0;
@@ -520,6 +531,8 @@ out:
return err;
}
+/* Called when 'unbind'. This means we must _NOT_ call pci_reset_function or
+ * other functions that take the sysfs lock. */
static void pcistub_remove(struct pci_dev *dev)
{
struct pcistub_device *psdev, *found_psdev = NULL;
@@ -551,6 +564,8 @@ static void pcistub_remove(struct pci_dev *dev)
pr_warn("****** shutdown driver domain before binding device\n");
pr_warn("****** to other drivers or domains\n");
+ /* N.B. This ends up calling pcistub_put_pci_dev which ends up
+ * doing the FLR. */
xen_pcibk_release_pci_dev(found_psdev->pdev,
found_psdev->dev);
}