libata: add init helpers including ata_pci_prepare_native_host()

These will be used to convert LLDs to new init model.

* Add irq_handler field to port_info.  In new init model, requesting
  IRQ is LLD's responsibility and libata doesn't need to know about
  irq_handler.  Most LLDs can simply register their irq_handler but
  some need different irq_handler depending on specific chip.  The
  added port_info->irq_handler field can be used by LLDs to select
  the matching IRQ handler in such cases.

* Add ata_dummy_port_info.

* Implement ata_pci_prepare_native_host(), a helper to alloc ATA host,
  acquire all resources and init the host in one go.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8d3ae66..2a38aa2 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6623,6 +6623,10 @@
 	.port_stop		= ata_dummy_noret,
 };
 
+const struct ata_port_info ata_dummy_port_info = {
+	.port_ops		= &ata_dummy_port_ops,
+};
+
 /*
  * libata is essentially a library of internal helper functions for
  * low-level ATA host controller drivers.  As such, the API/ABI is
@@ -6634,6 +6638,7 @@
 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
+EXPORT_SYMBOL_GPL(ata_dummy_port_info);
 EXPORT_SYMBOL_GPL(ata_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_std_ports);
 EXPORT_SYMBOL_GPL(ata_host_init);
@@ -6727,6 +6732,7 @@
 EXPORT_SYMBOL_GPL(pci_test_config_bits);
 EXPORT_SYMBOL_GPL(ata_pci_init_native_mode);
 EXPORT_SYMBOL_GPL(ata_pci_init_native_host);
+EXPORT_SYMBOL_GPL(ata_pci_prepare_native_host);
 EXPORT_SYMBOL_GPL(ata_pci_init_one);
 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
 #ifdef CONFIG_PM
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index d551fa1..142120c 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -663,13 +663,12 @@
 
 	for (i = 0; i < 2; i++) {
 		struct ata_port *ap = host->ports[i];
-		struct ata_ioports *ioaddr = &ap->ioaddr;
 		void __iomem *bmdma = host->iomap[4] + 8 * i;
 
 		if (ata_port_is_dummy(ap))
 			continue;
 
-		ioaddr->bmdma_addr = bmdma;
+		ap->ioaddr.bmdma_addr = bmdma;
 		if ((!(ap->flags & ATA_FLAG_IGN_SIMPLEX)) &&
 		    (ioread8(bmdma + 2) & 0x80))
 			host->flags |= ATA_HOST_SIMPLEX;
@@ -742,6 +741,70 @@
 	return 0;
 }
 
+/**
+ *	ata_pci_prepare_native_host - helper to prepare native PCI ATA host
+ *	@pdev: target PCI device
+ *	@ppi: array of port_info
+ *	@n_ports: number of ports to allocate
+ *	@r_host: out argument for the initialized ATA host
+ *
+ *	Helper to allocate ATA host for @pdev, acquire all native PCI
+ *	resources and initialize it accordingly in one go.
+ *
+ *	LOCKING:
+ *	Inherited from calling layer (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int ata_pci_prepare_native_host(struct pci_dev *pdev,
+				const struct ata_port_info * const * ppi,
+				int n_ports, struct ata_host **r_host)
+{
+	struct ata_host *host;
+	unsigned int port_mask;
+	int rc;
+
+	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL))
+		return -ENOMEM;
+
+	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
+	if (!host) {
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "failed to allocate ATA host\n");
+		rc = -ENOMEM;
+		goto err_out;
+	}
+
+	port_mask = ATA_PORT_PRIMARY;
+	if (n_ports > 1)
+		port_mask |= ATA_PORT_SECONDARY;
+
+	rc = ata_pci_init_native_host(host, port_mask);
+	if (rc)
+		goto err_out;
+
+	/* init DMA related stuff */
+	rc = ata_pci_init_bmdma(host);
+	if (rc)
+		goto err_bmdma;
+
+	devres_remove_group(&pdev->dev, NULL);
+	*r_host = host;
+	return 0;
+
+ err_bmdma:
+	/* This is necessary because PCI and iomap resources are
+	 * merged and releasing the top group won't release the
+	 * acquired resources if some of those have been acquired
+	 * before entering this function.
+	 */
+	pcim_iounmap_regions(pdev, 0xf);
+ err_out:
+	devres_release_group(&pdev->dev, NULL);
+	return rc;
+}
+
 struct ata_legacy_devres {
 	unsigned int	mask;
 	unsigned long	cmd_port[2];