drm/vmwgfx: Convert to Linux IRQ interfaces

Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
don't benefit from using it.

Vmwgfx already uses Linux IRQ functions. All that's left to replace
is the reference to struct drm_device.irq. Use irq value of struct
pci_dev instead.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210706072253.6844-1-tzimmermann@suse.de

drivers/gpu/drm/vmwgfx/vmwgfx_irq.c

@@ -25,6 +25,7 @@
  *
  **************************************************************************/
 
+#include <linux/pci.h>
 #include <linux/sched/signal.h>
 
 #include "vmwgfx_drv.h"
@@ -287,6 +288,7 @@ static void vmw_irq_preinstall(struct drm_device *dev)
 void vmw_irq_uninstall(struct drm_device *dev)
 {
 	struct vmw_private *dev_priv = vmw_priv(dev);
+	struct pci_dev *pdev = to_pci_dev(dev->dev);
 	uint32_t status;
 
 	if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
@@ -297,7 +299,7 @@ void vmw_irq_uninstall(struct drm_device *dev)
 	status = vmw_irq_status_read(dev_priv);
 	vmw_irq_status_write(dev_priv, status);
 
-	free_irq(dev->irq, dev);
+	free_irq(pdev->irq, dev);
 }
 
 /**
@@ -309,16 +311,8 @@ void vmw_irq_uninstall(struct drm_device *dev)
  */
 int vmw_irq_install(struct drm_device *dev, int irq)
 {
-	int ret;
-
 	vmw_irq_preinstall(dev);
 
-	ret = request_threaded_irq(irq, vmw_irq_handler, vmw_thread_fn,
-				   IRQF_SHARED, VMWGFX_DRIVER_NAME, dev);
-	if (ret < 0)
-		return ret;
-
-	dev->irq = irq;
-
-	return ret;
+	return request_threaded_irq(irq, vmw_irq_handler, vmw_thread_fn,
+				    IRQF_SHARED, VMWGFX_DRIVER_NAME, dev);
 }