PCI: hv: Convert remove_lock to refcount

Use refcount instead of atomic for the reference counting
on bus. Refcount is safer because it handles overflow correctly.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
[lorenzo.pieralisi@arm.com: updated commit subject]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 522fd76..b03a81b 100644 (file)
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -433,7 +433,7 @@ enum hv_pcibus_state {
 struct hv_pcibus_device {
        struct pci_sysdata sysdata;
        enum hv_pcibus_state state;
-       atomic_t remove_lock;
+       refcount_t remove_lock;
        struct hv_device *hdev;
        resource_size_t low_mmio_space;
        resource_size_t high_mmio_space;
@@ -2430,12 +2430,12 @@ static int hv_send_resources_released(struct hv_device *hdev)
 
 static void get_hvpcibus(struct hv_pcibus_device *hbus)
 {
-       atomic_inc(&hbus->remove_lock);
+       refcount_inc(&hbus->remove_lock);
 }
 
 static void put_hvpcibus(struct hv_pcibus_device *hbus)
 {
-       if (atomic_dec_and_test(&hbus->remove_lock))
+       if (refcount_dec_and_test(&hbus->remove_lock))
                complete(&hbus->remove_event);
 }
 
@@ -2479,7 +2479,7 @@ static int hv_pci_probe(struct hv_device *hdev,
                               hdev->dev_instance.b[8] << 8;
 
        hbus->hdev = hdev;
-       atomic_inc(&hbus->remove_lock);
+       refcount_set(&hbus->remove_lock, 1);
        INIT_LIST_HEAD(&hbus->children);
        INIT_LIST_HEAD(&hbus->dr_list);
        INIT_LIST_HEAD(&hbus->resources_for_children);