AHCI: Add generic MSI-X interrupt support to SATA PCI driver

index c7a92a743ed0..7ba5332476c6 100644
@@ -1201,17 +1201,17 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
 {}
 #endif
 
-static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
-				struct ahci_host_priv *hpriv)
+static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
+			struct ahci_host_priv *hpriv)
 {
 	int rc, nvec;
 
 	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
-		goto intx;
+		return -ENODEV;
 
 	nvec = pci_msi_vec_count(pdev);
 	if (nvec < 0)
-		goto intx;
+		return nvec;
 
 	/*
 	 * If number of MSIs is less than number of ports then Sharing Last

@@ -1224,8 +1224,8 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
 	rc = pci_enable_msi_exact(pdev, nvec);
 	if (rc == -ENOSPC)
 		goto single_msi;
-	else if (rc < 0)
-		goto intx;
+	if (rc < 0)
+		return rc;
 
 	/* fallback to single MSI mode if the controller enforced MRSM mode */
 	if (readl(hpriv->mmio + HOST_CTL) & HOST_MRSM) {

@@ -1240,12 +1240,25 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
 	return nvec;
 
 single_msi:
-	if (pci_enable_msi(pdev))
-		goto intx;
+	rc = pci_enable_msi(pdev);
+	if (rc < 0)
+		return rc;
+
 	return 1;
+}
 
-intx:
+static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
+				struct ahci_host_priv *hpriv)
+{
+	int nvec;
+
+	nvec = ahci_init_msi(pdev, n_ports, hpriv);
+	if (nvec >= 0)
+		return nvec;
+
+	/* lagacy intx interrupts */
 	pci_intx(pdev, 1);
+
 	return 0;
 }
 

index 12489ce863c4..ed6a30cd681a 100644
@@ -433,6 +433,8 @@ static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id
 	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
 	if (!hpriv)
 		return -ENOMEM;
+
+	hpriv->irq = pdev->irq;
 	hpriv->flags |= (unsigned long)pi.private_data;
 
 	if (!(hpriv->flags & AHCI_HFLAG_NO_MSI))

@@ -498,7 +500,7 @@ static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id
 	acard_ahci_pci_print_info(host);
 
 	pci_set_master(pdev);
-	return ahci_host_activate(host, pdev->irq, &acard_ahci_sht);
+	return ahci_host_activate(host, &acard_ahci_sht);
 }
 
 module_pci_driver(acard_ahci_pci_driver);

index 7ba5332476c6..a3c66c3bb76e 100644
@@ -1237,14 +1237,18 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 	if (nvec > 1)
 		hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
 
-	return nvec;
+	goto out;
 
 single_msi:
+	nvec = 1;
+
 	rc = pci_enable_msi(pdev);
 	if (rc < 0)
 		return rc;
+out:
+	hpriv->irq = pdev->irq;
 
-	return 1;
+	return nvec;
 }
 
 static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,

@@ -1258,6 +1262,7 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
 
 	/* lagacy intx interrupts */
 	pci_intx(pdev, 1);
+	hpriv->irq = pdev->irq;
 
 	return 0;
 }

@@ -1423,13 +1428,13 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	 */
 	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
 
-	ahci_init_interrupts(pdev, n_ports, hpriv);
-
 	host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
 	if (!host)
 		return -ENOMEM;
 	host->private_data = hpriv;
 
+	ahci_init_interrupts(pdev, n_ports, hpriv);
+
 	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
 		host->flags |= ATA_HOST_PARALLEL_SCAN;
 	else

@@ -1475,7 +1480,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_master(pdev);
 
-	return ahci_host_activate(host, pdev->irq, &ahci_sht);
+	return ahci_host_activate(host, &ahci_sht);
 }
 
 module_pci_driver(ahci_pci_driver);

index f4429600e2bf..5b8e8a0fab48 100644
@@ -343,6 +343,7 @@ struct ahci_host_priv {
 	struct phy		**phys;
 	unsigned		nports;		/* Number of ports */
 	void			*plat_data;	/* Other platform data */
+	unsigned int		irq;		/* interrupt line */
 	/*
 	 * Optional ahci_start_engine override, if not set this gets set to the
 	 * default ahci_start_engine during ahci_save_initial_config, this can

@@ -395,8 +396,7 @@ void ahci_set_em_messages(struct ahci_host_priv *hpriv,
 			  struct ata_port_info *pi);
 int ahci_reset_em(struct ata_host *host);
 void ahci_print_info(struct ata_host *host, const char *scc_s);
-int ahci_host_activate(struct ata_host *host, int irq,
-		       struct scsi_host_template *sht);
+int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht);
 void ahci_error_handler(struct ata_port *ap);
 
 static inline void __iomem *__ahci_port_base(struct ata_host *host,

index 1add5baec584..1c99402a1017 100644
@@ -2344,7 +2344,7 @@ static int ahci_port_start(struct ata_port *ap)
 	/*
 	 * Switch to per-port locking in case each port has its own MSI vector.
 	 */
-	if ((hpriv->flags & AHCI_HFLAG_MULTI_MSI)) {
+	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI) {
 		spin_lock_init(&pp->lock);
 		ap->lock = &pp->lock;
 	}

@@ -2472,7 +2472,10 @@ static int ahci_host_activate_multi_irqs(struct ata_host *host, int irq,
 	rc = ata_host_start(host);
 	if (rc)
 		return rc;
-
+	/*
+	 * Requests IRQs according to AHCI-1.1 when multiple MSIs were
+	 * allocated. That is one MSI per port, starting from @irq.
+	 */
 	for (i = 0; i < host->n_ports; i++) {
 		struct ahci_port_priv *pp = host->ports[i]->private_data;
 

@@ -2511,23 +2514,18 @@ static int ahci_host_activate_multi_irqs(struct ata_host *host, int irq,
 /**
  *	ahci_host_activate - start AHCI host, request IRQs and register it
  *	@host: target ATA host
- *	@irq: base IRQ number to request
  *	@sht: scsi_host_template to use when registering the host
  *
- *	Similar to ata_host_activate, but requests IRQs according to AHCI-1.1
- *	when multiple MSIs were allocated. That is one MSI per port, starting
- *	from @irq.
- *
  *	LOCKING:
  *	Inherited from calling layer (may sleep).
  *
  *	RETURNS:
  *	0 on success, -errno otherwise.
  */
-int ahci_host_activate(struct ata_host *host, int irq,
-		       struct scsi_host_template *sht)
+int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
 {
 	struct ahci_host_priv *hpriv = host->private_data;
+	int irq = hpriv->irq;
 	int rc;
 
 	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI)

index d89305d289f6..aaa761b9081c 100644
@@ -518,6 +518,8 @@ int ahci_platform_init_host(struct platform_device *pdev,
 		return -EINVAL;
 	}
 
+	hpriv->irq = irq;
+
 	/* prepare host */
 	pi.private_data = (void *)(unsigned long)hpriv->flags;
 

@@ -588,7 +590,7 @@ int ahci_platform_init_host(struct platform_device *pdev,
 	ahci_init_controller(host);
 	ahci_print_info(host, "platform");
 
-	return ahci_host_activate(host, irq, sht);
+	return ahci_host_activate(host, sht);
 }
 EXPORT_SYMBOL_GPL(ahci_platform_init_host);
 

index 24e311fe2c1c..8638d575b2b9 100644
@@ -499,6 +499,7 @@ static int ahci_highbank_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	hpriv->irq = irq;
 	hpriv->flags |= (unsigned long)pi.private_data;
 
 	hpriv->mmio = devm_ioremap(dev, mem->start, resource_size(mem));

@@ -568,7 +569,7 @@ static int ahci_highbank_probe(struct platform_device *pdev)
 	ahci_init_controller(host);
 	ahci_print_info(host, "platform");
 
-	rc = ahci_host_activate(host, irq, &ahci_highbank_platform_sht);
+	rc = ahci_host_activate(host, &ahci_highbank_platform_sht);
 	if (rc)
 		goto err0;
 

index a3c66c3bb76e..30200e757cdb 100644
@@ -42,6 +42,7 @@
 #include <linux/device.h>
 #include <linux/dmi.h>
 #include <linux/gfp.h>
+#include <linux/msi.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_cmnd.h>
 #include <linux/libata.h>

@@ -52,6 +53,7 @@
 
 enum {
 	AHCI_PCI_BAR_STA2X11	= 0,
+	AHCI_PCI_BAR_CAVIUM	= 0,
 	AHCI_PCI_BAR_ENMOTUS	= 2,
 	AHCI_PCI_BAR_STANDARD	= 5,
 };

@@ -499,6 +501,9 @@ static const struct pci_device_id ahci_pci_tbl[] = {
 	/* Enmotus */
 	{ PCI_DEVICE(0x1c44, 0x8000), board_ahci },
 
+	/* Cavium */
+	{ PCI_DEVICE(0x177d, 0xa01c), .driver_data = board_ahci },
+
 	/* Generic, PCI class code for AHCI */
 	{ PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
 	  PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff, board_ahci },

@@ -1201,6 +1206,80 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
 {}
 #endif
 
+static struct msi_desc *msix_get_desc(struct pci_dev *dev, u16 entry)
+{
+	struct msi_desc *desc;
+
+	list_for_each_entry(desc, &dev->msi_list, list) {
+		if (desc->msi_attrib.entry_nr == entry)
+			return desc;
+	}
+
+	return NULL;
+}
+
+static int ahci_init_msix(struct pci_dev *pdev, unsigned int n_ports,
+			  struct ahci_host_priv *hpriv)
+{
+	struct msi_desc *desc;
+	int rc, nvec;
+	struct msix_entry entry = {};
+
+	/* Do not init MSI-X if MSI is disabled for the device */
+	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
+		return -ENODEV;
+
+	nvec = pci_msix_vec_count(pdev);
+	if (nvec < 0)
+		return nvec;
+
+	if (!nvec) {
+		rc = -ENODEV;
+		goto fail;
+	}
+
+	/*
+	 * Per-port msix interrupts are not supported. Assume single
+	 * port interrupts for:
+	 *
+	 *  n_ports == 1, or
+	 *  nvec < n_ports.
+	 *
+	 * We also need to check for n_ports != 0 which is implicitly
+	 * covered here since nvec > 0.
+	 */
+	if (n_ports != 1 && nvec >= n_ports) {
+		rc = -ENOSYS;
+		goto fail;
+	}
+
+	/*
+	 * There can exist more than one vector (e.g. for error
+	 * detection or hdd hotplug). Then the first vector is used,
+	 * all others are ignored. Only enable the first entry here
+	 * (entry.entry = 0).
+	 */
+	rc = pci_enable_msix_exact(pdev, &entry, 1);
+	if (rc < 0)
+		goto fail;
+
+	desc = msix_get_desc(pdev, 0);	/* first entry */
+	if (!desc) {
+		rc = -EINVAL;
+		goto fail;
+	}
+
+	hpriv->irq = desc->irq;
+
+	return 1;
+fail:
+	dev_err(&pdev->dev,
+		"failed to enable MSI-X with error %d, # of vectors: %d\n",
+		rc, nvec);
+
+	return rc;
+}
+
 static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 			struct ahci_host_priv *hpriv)
 {

@@ -1260,6 +1339,10 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
 	if (nvec >= 0)
 		return nvec;
 
+	nvec = ahci_init_msix(pdev, n_ports, hpriv);
+	if (nvec >= 0)
+		return nvec;
+
 	/* lagacy intx interrupts */
 	pci_intx(pdev, 1);
 	hpriv->irq = pdev->irq;

@@ -1302,11 +1385,13 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		dev_info(&pdev->dev,
 			 "PDC42819 can only drive SATA devices with this driver\n");
 
-	/* Both Connext and Enmotus devices use non-standard BARs */
+	/* Some devices use non-standard BARs */
 	if (pdev->vendor == PCI_VENDOR_ID_STMICRO && pdev->device == 0xCC06)
 		ahci_pci_bar = AHCI_PCI_BAR_STA2X11;
 	else if (pdev->vendor == 0x1c44 && pdev->device == 0x8000)
 		ahci_pci_bar = AHCI_PCI_BAR_ENMOTUS;
+	else if (pdev->vendor == 0x177d && pdev->device == 0xa01c)
+		ahci_pci_bar = AHCI_PCI_BAR_CAVIUM;
 
 	/*
 	 * The JMicron chip 361/363 contains one SATA controller and one