vgaarb: provide a vga_client_unregister wrapper

Add a trivial wrapper for the unregister case that sets all fields to
NULL.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-6-hch@lst.deAcked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -3802,7 +3802,7 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
 		vga_switcheroo_fini_domain_pm_ops(adev->dev);
 	}
 	if ((adev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
-		vga_client_register(adev->pdev, NULL, NULL, NULL);
+		vga_client_unregister(adev->pdev);
 
 	if (IS_ENABLED(CONFIG_PERF_EVENTS))
 		amdgpu_pmu_fini(adev);

drivers/gpu/drm/drm_irq.c

@@ -136,7 +136,7 @@ int drm_irq_install(struct drm_device *dev, int irq)
 	if (ret < 0) {
 		dev->irq_enabled = false;
 		if (drm_core_check_feature(dev, DRIVER_LEGACY))
-			vga_client_register(to_pci_dev(dev->dev), NULL, NULL, NULL);
+			vga_client_unregister(to_pci_dev(dev->dev));
 		free_irq(irq, dev);
 	} else {
 		dev->irq = irq;
@@ -198,7 +198,7 @@ int drm_irq_uninstall(struct drm_device *dev)
 	DRM_DEBUG("irq=%d\n", dev->irq);
 
 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
-		vga_client_register(to_pci_dev(dev->dev), NULL, NULL, NULL);
+		vga_client_unregister(to_pci_dev(dev->dev));
 
 	if (dev->driver->irq_uninstall)
 		dev->driver->irq_uninstall(dev);

drivers/gpu/drm/i915/display/intel_vga.c

@@ -158,5 +158,5 @@ void intel_vga_unregister(struct drm_i915_private *i915)
 {
 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
 
-	vga_client_register(pdev, NULL, NULL, NULL);
+	vga_client_unregister(pdev);
 }

drivers/gpu/drm/nouveau/nouveau_vga.c

@@ -118,7 +118,7 @@ nouveau_vga_fini(struct nouveau_drm *drm)
 		return;
 	pdev = to_pci_dev(dev->dev);
 
-	vga_client_register(pdev, NULL, NULL, NULL);
+	vga_client_unregister(pdev);
 
 	if (pci_is_thunderbolt_attached(pdev))
 		return;

drivers/gpu/drm/radeon/radeon_device.c

@@ -1530,7 +1530,7 @@ void radeon_device_fini(struct radeon_device *rdev)
 		vga_switcheroo_unregister_client(rdev->pdev);
 	if (rdev->flags & RADEON_IS_PX)
 		vga_switcheroo_fini_domain_pm_ops(rdev->dev);
-	vga_client_register(rdev->pdev, NULL, NULL, NULL);
+	vga_client_unregister(rdev->pdev);
 	if (rdev->rio_mem)
 		pci_iounmap(rdev->pdev, rdev->rio_mem);
 	rdev->rio_mem = NULL;

drivers/gpu/vga/vgaarb.c

@@ -877,8 +877,7 @@ EXPORT_SYMBOL(vga_set_legacy_decoding);
  * This function does not check whether a client for @pdev has been registered
  * already.
  *
- * To unregister just call this function with @irq_set_state and @set_vga_decode
- * both set to NULL for the same @pdev as originally used to register them.
+ * To unregister just call vga_client_unregister().
  *
  * Returns: 0 on success, -1 on failure
  */

drivers/vfio/pci/vfio_pci.c

@@ -1964,7 +1964,7 @@ static void vfio_pci_vga_uninit(struct vfio_pci_device *vdev)
 
 	if (!vfio_pci_is_vga(pdev))
 		return;
-	vga_client_register(pdev, NULL, NULL, NULL);
+	vga_client_unregister(pdev);
 	vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
 					      VGA_RSRC_LEGACY_IO |
 					      VGA_RSRC_LEGACY_MEM);

include/linux/vgaarb.h

@@ -116,4 +116,9 @@ static inline int vga_get_uninterruptible(struct pci_dev *pdev,
        return vga_get(pdev, rsrc, 0);
 }
 
+static inline void vga_client_unregister(struct pci_dev *pdev)
+{
+	vga_client_register(pdev, NULL, NULL, NULL);
+}
+
 #endif /* LINUX_VGA_H */