virtio-pci: alloc only resources actually used.

Move resource allocation from common code to legacy and modern code.
Only request resources actually used, i.e. bar0 in legacy mode and
the bar(s) specified by capabilities in modern mode.

Signed-off-by: Gerd Hoffmann <[e-mail]>

Signed-off-by: Michael S. Tsirkin <[e-mail]>

drivers/virtio/virtio_pci_common.c

···
 	if (rc)
 		goto err_enable_device;
 
-	rc = pci_request_regions(pci_dev, "virtio-pci");
-	if (rc)
-		goto err_request_regions;
-
 	if (force_legacy) {
 		rc = virtio_pci_legacy_probe(vp_dev);
 		/* Also try modern mode if we can't map BAR0 (no IO space). */
···
 	else
 	     virtio_pci_modern_remove(vp_dev);
 err_probe:
-	pci_release_regions(pci_dev);
-err_request_regions:
 	pci_disable_device(pci_dev);
 err_enable_device:
 	kfree(vp_dev);
···
 	else
 		virtio_pci_modern_remove(vp_dev);
 
-	pci_release_regions(pci_dev);
 	pci_disable_device(pci_dev);
 }
 

drivers/virtio/virtio_pci_common.h

···
 	/* Multiply queue_notify_off by this value. (non-legacy mode). */
 	u32 notify_offset_multiplier;
 
+	int modern_bars;
+
 	/* Legacy only field */
 	/* the IO mapping for the PCI config space */
 	void __iomem *ioaddr;

drivers/virtio/virtio_pci_legacy.c

···
 int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 {
 	struct pci_dev *pci_dev = vp_dev->pci_dev;
+	int rc;
 
 	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
 	if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
···
 		return -ENODEV;
 	}
 
+	rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
+	if (rc)
+		return rc;
+
+	rc = -ENOMEM;
 	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
 	if (!vp_dev->ioaddr)
-		return -ENOMEM;
+		goto err_iomap;
 
 	vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
 
···
 	vp_dev->del_vq = del_vq;
 
 	return 0;
+
+err_iomap:
+	pci_release_region(pci_dev, 0);
+	return rc;
 }
 
 void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
···
 	struct pci_dev *pci_dev = vp_dev->pci_dev;
 
 	pci_iounmap(pci_dev, vp_dev->ioaddr);
+	pci_release_region(pci_dev, 0);
 }

drivers/virtio/virtio_pci_modern.c

···
  * Returns offset of the capability, or 0.
  */
 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
-					     u32 ioresource_types)
+					     u32 ioresource_types, int *bars)
 {
 	int pos;
 
···
 
 		if (type == cfg_type) {
 			if (pci_resource_len(dev, bar) &&
-			    pci_resource_flags(dev, bar) & ioresource_types)
+			    pci_resource_flags(dev, bar) & ioresource_types) {
+				*bars |= (1 << bar);
 				return pos;
+			}
 		}
 	}
 	return 0;
···
 
 	/* check for a common config: if not, use legacy mode (bar 0). */
 	common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
-					    IORESOURCE_IO | IORESOURCE_MEM);
+					    IORESOURCE_IO | IORESOURCE_MEM,
+					    &vp_dev->modern_bars);
 	if (!common) {
 		dev_info(&pci_dev->dev,
 			 "virtio_pci: leaving for legacy driver\n");
···
 
 	/* If common is there, these should be too... */
 	isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
-					 IORESOURCE_IO | IORESOURCE_MEM);
+					 IORESOURCE_IO | IORESOURCE_MEM,
+					 &vp_dev->modern_bars);
 	notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
-					    IORESOURCE_IO | IORESOURCE_MEM);
+					    IORESOURCE_IO | IORESOURCE_MEM,
+					    &vp_dev->modern_bars);
 	if (!isr || !notify) {
 		dev_err(&pci_dev->dev,
 			"virtio_pci: missing capabilities %i/%i/%i\n",
···
 	 * device-specific configuration.
 	 */
 	device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
-					    IORESOURCE_IO | IORESOURCE_MEM);
+					    IORESOURCE_IO | IORESOURCE_MEM,
+					    &vp_dev->modern_bars);
+
+	err = pci_request_selected_regions(pci_dev, vp_dev->modern_bars,
+					   "virtio-pci-modern");
+	if (err)
+		return err;
 
 	err = -EINVAL;
 	vp_dev->common = map_capability(pci_dev, common,
···
 		pci_iounmap(pci_dev, vp_dev->notify_base);
 	pci_iounmap(pci_dev, vp_dev->isr);
 	pci_iounmap(pci_dev, vp_dev->common);
+	pci_release_selected_regions(pci_dev, vp_dev->modern_bars);
 }