devres: implement pcim_iomap_regions()

Implement pcim_iomap_regions().  This function takes mask of BARs to
request and iomap.  No BAR should have length of zero.  BARs are
iomapped using pcim_iomap_table().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

include/linux/io.h

@@ -45,6 +45,8 @@ void __iomem * pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);
 void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr);
 void __iomem * const * pcim_iomap_table(struct pci_dev *pdev);
 
+int pcim_iomap_regions(struct pci_dev *pdev, u16 mask, const char *name);
+
 /**
  *	check_signature		-	find BIOS signatures
  *	@io_addr: mmio address to check

lib/iomap.c

@@ -498,3 +498,56 @@ void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
 	WARN_ON(1);
 }
 EXPORT_SYMBOL(pcim_iounmap);
+
+/**
+ * pcim_iomap_regions - Request and iomap PCI BARs
+ * @pdev: PCI device to map IO resources for
+ * @mask: Mask of BARs to request and iomap
+ * @name: Name used when requesting regions
+ *
+ * Request and iomap regions specified by @mask.
+ */
+int pcim_iomap_regions(struct pci_dev *pdev, u16 mask, const char *name)
+{
+	void __iomem * const *iomap;
+	int i, rc;
+
+	iomap = pcim_iomap_table(pdev);
+	if (!iomap)
+		return -ENOMEM;
+
+	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+		unsigned long len;
+
+		if (!(mask & (1 << i)))
+			continue;
+
+		rc = -EINVAL;
+		len = pci_resource_len(pdev, i);
+		if (!len)
+			goto err_inval;
+
+		rc = pci_request_region(pdev, i, name);
+		if (rc)
+			goto err_region;
+
+		rc = -ENOMEM;
+		if (!pcim_iomap(pdev, i, 0))
+			goto err_iomap;
+	}
+
+	return 0;
+
+ err_iomap:
+	pcim_iounmap(pdev, iomap[i]);
+ err_region:
+	pci_release_region(pdev, i);
+ err_inval:
+	while (--i >= 0) {
+		pcim_iounmap(pdev, iomap[i]);
+		pci_release_region(pdev, i);
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL(pcim_iomap_regions);