Merge branch 'stable/pci.cleanups.v1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

* 'stable/pci.cleanups.v1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pci: Use 'acpi_gsi_to_irq' value unconditionally.
  xen/pci: Remove 'xen_allocate_pirq_gsi'.
  xen/pci: Retire unnecessary #ifdef CONFIG_ACPI
  xen/pci: Move the allocation of IRQs when there are no IOAPIC's to the end
  xen/pci: Squash pci_xen_initial_domain and xen_setup_pirqs together.
  xen/pci: Use the xen_register_pirq for HVM and initial domain users
  xen/pci: In xen_register_pirq bind the GSI to the IRQ after the hypercall.
  xen/pci: Provide #ifdef CONFIG_ACPI to easy code squashing.
  xen/pci: Update comments and fix empty spaces.
  xen/pci: Shuffle code around.

4 files changed, 165 insertions, 220 deletions

diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index 4fbda9a..968d57d 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -14,13 +14,14 @@ static inline int pci_xen_hvm_init(void)
 }
 #endif
 #if defined(CONFIG_XEN_DOM0)
-void __init xen_setup_pirqs(void);
+int __init pci_xen_initial_domain(void);
 int xen_find_device_domain_owner(struct pci_dev *dev);
 int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
 int xen_unregister_device_domain_owner(struct pci_dev *dev);
 #else
-static inline void __init xen_setup_pirqs(void)
+static inline int __init pci_xen_initial_domain(void)
 {
+	return -1;
 }
 static inline int xen_find_device_domain_owner(struct pci_dev *dev)
 {
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index f567965..1017c7b 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -1,8 +1,13 @@
 /*
- * Xen PCI Frontend Stub - puts some "dummy" functions in to the Linux
- *			   x86 PCI core to support the Xen PCI Frontend
+ * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
+ * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
+ * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
+ * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
+ * 0xcf8 PCI configuration read/write.
  *
  *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ *           Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+ *           Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  */
 #include <linux/module.h>
 #include <linux/init.h>
@@ -19,22 +24,53 @@
 #include <xen/events.h>
 #include <asm/xen/pci.h>
 
+static int xen_pcifront_enable_irq(struct pci_dev *dev)
+{
+	int rc;
+	int share = 1;
+	int pirq;
+	u8 gsi;
+
+	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
+	if (rc < 0) {
+		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
+			 rc);
+		return rc;
+	}
+	/* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
+	pirq = gsi;
+
+	if (gsi < NR_IRQS_LEGACY)
+		share = 0;
+
+	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
+	if (rc < 0) {
+		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
+			 gsi, pirq, rc);
+		return rc;
+	}
+
+	dev->irq = rc;
+	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
+	return 0;
+}
+
 #ifdef CONFIG_ACPI
-static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
-				 int trigger, int polarity)
+static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
+			     bool set_pirq)
 {
-	int rc, irq;
+	int rc, pirq = -1, irq = -1;
 	struct physdev_map_pirq map_irq;
 	int shareable = 0;
 	char *name;
 
-	if (!xen_hvm_domain())
-		return -1;
+	if (set_pirq)
+		pirq = gsi;
 
 	map_irq.domid = DOMID_SELF;
 	map_irq.type = MAP_PIRQ_TYPE_GSI;
 	map_irq.index = gsi;
-	map_irq.pirq = -1;
+	map_irq.pirq = pirq;
 
 	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
 	if (rc) {
@@ -42,7 +78,7 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 		return -1;
 	}
 
-	if (trigger == ACPI_EDGE_SENSITIVE) {
+	if (triggering == ACPI_EDGE_SENSITIVE) {
 		shareable = 0;
 		name = "ioapic-edge";
 	} else {
@@ -50,12 +86,63 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 		name = "ioapic-level";
 	}
 
+	if (gsi_override >= 0)
+		gsi = gsi_override;
+
 	irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
+	if (irq < 0)
+		goto out;
+
+	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
+out:
+	return irq;
+}
+
+static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
+				     int trigger, int polarity)
+{
+	if (!xen_hvm_domain())
+		return -1;
 
-	printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
+	return xen_register_pirq(gsi, -1 /* no GSI override */, trigger,
+				 false /* no mapping of GSI to PIRQ */);
+}
+
+#ifdef CONFIG_XEN_DOM0
+static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
+{
+	int rc, irq;
+	struct physdev_setup_gsi setup_gsi;
+
+	if (!xen_pv_domain())
+		return -1;
+
+	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
+			gsi, triggering, polarity);
+
+	irq = xen_register_pirq(gsi, gsi_override, triggering, true);
+
+	setup_gsi.gsi = gsi;
+	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
+	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+
+	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
+	if (rc == -EEXIST)
+		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
+	else if (rc) {
+		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
+				gsi, rc);
+	}
 
 	return irq;
 }
+
+static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
+				 int trigger, int polarity)
+{
+	return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
+}
+#endif
 #endif
 
 #if defined(CONFIG_PCI_MSI)
@@ -65,6 +152,43 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 struct xen_pci_frontend_ops *xen_pci_frontend;
 EXPORT_SYMBOL_GPL(xen_pci_frontend);
 
+static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	int irq, ret, i;
+	struct msi_desc *msidesc;
+	int *v;
+
+	v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
+	if (!v)
+		return -ENOMEM;
+
+	if (type == PCI_CAP_ID_MSIX)
+		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
+	else
+		ret = xen_pci_frontend_enable_msi(dev, v);
+	if (ret)
+		goto error;
+	i = 0;
+	list_for_each_entry(msidesc, &dev->msi_list, list) {
+		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
+					       (type == PCI_CAP_ID_MSIX) ?
+					       "pcifront-msi-x" :
+					       "pcifront-msi",
+						DOMID_SELF);
+		if (irq < 0)
+			goto free;
+		i++;
+	}
+	kfree(v);
+	return 0;
+
+error:
+	dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
+free:
+	kfree(v);
+	return ret;
+}
+
 #define XEN_PIRQ_MSI_DATA  (MSI_DATA_TRIGGER_EDGE | \
 		MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
 
@@ -123,67 +247,6 @@ error:
 	return -ENODEV;
 }
 
-/*
- * For MSI interrupts we have to use drivers/xen/event.s functions to
- * allocate an irq_desc and setup the right */
-
-
-static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
-{
-	int irq, ret, i;
-	struct msi_desc *msidesc;
-	int *v;
-
-	v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
-	if (!v)
-		return -ENOMEM;
-
-	if (type == PCI_CAP_ID_MSIX)
-		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
-	else
-		ret = xen_pci_frontend_enable_msi(dev, v);
-	if (ret)
-		goto error;
-	i = 0;
-	list_for_each_entry(msidesc, &dev->msi_list, list) {
-		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
-					       (type == PCI_CAP_ID_MSIX) ?
-					       "pcifront-msi-x" :
-					       "pcifront-msi",
-						DOMID_SELF);
-		if (irq < 0)
-			goto free;
-		i++;
-	}
-	kfree(v);
-	return 0;
-
-error:
-	dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
-free:
-	kfree(v);
-	return ret;
-}
-
-static void xen_teardown_msi_irqs(struct pci_dev *dev)
-{
-	struct msi_desc *msidesc;
-
-	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
-	if (msidesc->msi_attrib.is_msix)
-		xen_pci_frontend_disable_msix(dev);
-	else
-		xen_pci_frontend_disable_msi(dev);
-
-	/* Free the IRQ's and the msidesc using the generic code. */
-	default_teardown_msi_irqs(dev);
-}
-
-static void xen_teardown_msi_irq(unsigned int irq)
-{
-	xen_destroy_irq(irq);
-}
-
 #ifdef CONFIG_XEN_DOM0
 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
@@ -242,45 +305,28 @@ out:
 	return ret;
 }
 #endif
-#endif
 
-static int xen_pcifront_enable_irq(struct pci_dev *dev)
+static void xen_teardown_msi_irqs(struct pci_dev *dev)
 {
-	int rc;
-	int share = 1;
-	int pirq;
-	u8 gsi;
-
-	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
-	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
-			 rc);
-		return rc;
-	}
-
-	rc = xen_allocate_pirq_gsi(gsi);
-	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI: failed to allocate a PIRQ for GSI%d: %d\n",
-			 gsi, rc);
-		return rc;
-	}
-	pirq = rc;
+	struct msi_desc *msidesc;
 
-	if (gsi < NR_IRQS_LEGACY)
-		share = 0;
+	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
+	if (msidesc->msi_attrib.is_msix)
+		xen_pci_frontend_disable_msix(dev);
+	else
+		xen_pci_frontend_disable_msi(dev);
 
-	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
-	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
-			 gsi, pirq, rc);
-		return rc;
-	}
+	/* Free the IRQ's and the msidesc using the generic code. */
+	default_teardown_msi_irqs(dev);
+}
 
-	dev->irq = rc;
-	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
-	return 0;
+static void xen_teardown_msi_irq(unsigned int irq)
+{
+	xen_destroy_irq(irq);
 }
 
+#endif
+
 int __init pci_xen_init(void)
 {
 	if (!xen_pv_domain() || xen_initial_domain())
@@ -327,79 +373,6 @@ int __init pci_xen_hvm_init(void)
 }
 
 #ifdef CONFIG_XEN_DOM0
-static int xen_register_pirq(u32 gsi, int gsi_override, int triggering)
-{
-	int rc, pirq, irq = -1;
-	struct physdev_map_pirq map_irq;
-	int shareable = 0;
-	char *name;
-
-	if (!xen_pv_domain())
-		return -1;
-
-	if (triggering == ACPI_EDGE_SENSITIVE) {
-		shareable = 0;
-		name = "ioapic-edge";
-	} else {
-		shareable = 1;
-		name = "ioapic-level";
-	}
-	pirq = xen_allocate_pirq_gsi(gsi);
-	if (pirq < 0)
-		goto out;
-
-	if (gsi_override >= 0)
-		irq = xen_bind_pirq_gsi_to_irq(gsi_override, pirq, shareable, name);
-	else
-		irq = xen_bind_pirq_gsi_to_irq(gsi, pirq, shareable, name);
-	if (irq < 0)
-		goto out;
-
-	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", pirq, irq, gsi);
-
-	map_irq.domid = DOMID_SELF;
-	map_irq.type = MAP_PIRQ_TYPE_GSI;
-	map_irq.index = gsi;
-	map_irq.pirq = pirq;
-
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
-	if (rc) {
-		printk(KERN_WARNING "xen map irq failed %d\n", rc);
-		return -1;
-	}
-
-out:
-	return irq;
-}
-
-static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
-{
-	int rc, irq;
-	struct physdev_setup_gsi setup_gsi;
-
-	if (!xen_pv_domain())
-		return -1;
-
-	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
-			gsi, triggering, polarity);
-
-	irq = xen_register_pirq(gsi, gsi_override, triggering);
-
-	setup_gsi.gsi = gsi;
-	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
-	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
-
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
-	if (rc == -EEXIST)
-		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
-	else if (rc) {
-		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
-				gsi, rc);
-	}
-
-	return irq;
-}
-
 static __init void xen_setup_acpi_sci(void)
 {
 	int rc;
@@ -419,7 +392,7 @@ static __init void xen_setup_acpi_sci(void)
 	}
 	trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 	polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
-	
+
 	printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
 			"polarity=%d\n", gsi, trigger, polarity);
 
@@ -434,10 +407,9 @@ static __init void xen_setup_acpi_sci(void)
 	 * the ACPI interpreter and keels over since IRQ 9 has not been
 	 * setup as we had setup IRQ 20 for it).
 	 */
-	/* Check whether the GSI != IRQ */
 	if (acpi_gsi_to_irq(gsi, &irq) == 0) {
-		if (irq >= 0 && irq != gsi)
-			/* Bugger, we MUST have that IRQ. */
+		/* Use the provided value if it's valid. */
+		if (irq >= 0)
 			gsi_override = irq;
 	}
 
@@ -447,41 +419,16 @@ static __init void xen_setup_acpi_sci(void)
 	return;
 }
 
-static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
-				 int trigger, int polarity)
+int __init pci_xen_initial_domain(void)
 {
-	return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
-}
+	int irq;
 
-static int __init pci_xen_initial_domain(void)
-{
 #ifdef CONFIG_PCI_MSI
 	x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
 	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 #endif
 	xen_setup_acpi_sci();
 	__acpi_register_gsi = acpi_register_gsi_xen;
-
-	return 0;
-}
-
-void __init xen_setup_pirqs(void)
-{
-	int pirq, irq;
-
-	pci_xen_initial_domain();
-
-	if (0 == nr_ioapics) {
-		for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
-			pirq = xen_allocate_pirq_gsi(irq);
-			if (WARN(pirq < 0,
-				 "Could not allocate PIRQ for legacy interrupt\n"))
-				break;
-			irq = xen_bind_pirq_gsi_to_irq(irq, pirq, 0, "xt-pic");
-		}
-		return;
-	}
-
 	/* Pre-allocate legacy irqs */
 	for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
 		int trigger, polarity;
@@ -490,12 +437,16 @@ void __init xen_setup_pirqs(void)
 			continue;
 
 		xen_register_pirq(irq, -1 /* no GSI override */,
-			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE);
+			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
+			true /* Map GSI to PIRQ */);
 	}
+	if (0 == nr_ioapics) {
+		for (irq = 0; irq < NR_IRQS_LEGACY; irq++)
+			xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
+	}
+	return 0;
 }
-#endif
 
-#ifdef CONFIG_XEN_DOM0
 struct xen_device_domain_owner {
 	domid_t domain;
 	struct pci_dev *dev;
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 30df85d..da70f5c 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -615,11 +615,6 @@ static int find_irq_by_gsi(unsigned gsi)
 	return -1;
 }
 
-int xen_allocate_pirq_gsi(unsigned gsi)
-{
-	return gsi;
-}
-
 /*
  * Do not make any assumptions regarding the relationship between the
  * IRQ number returned here and the Xen pirq argument.
@@ -1693,6 +1688,6 @@ void __init xen_init_IRQ(void)
 	} else {
 		irq_ctx_init(smp_processor_id());
 		if (xen_initial_domain())
-			xen_setup_pirqs();
+			pci_xen_initial_domain();
 	}
 }
diff --git a/include/xen/events.h b/include/xen/events.h
index 9af21e1..d287997 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -74,8 +74,6 @@ int xen_set_callback_via(uint64_t via);
 void xen_evtchn_do_upcall(struct pt_regs *regs);
 void xen_hvm_evtchn_do_upcall(void);
 
-/* Allocate a pirq for a physical interrupt, given a gsi. */
-int xen_allocate_pirq_gsi(unsigned gsi);
 /* Bind a pirq for a physical interrupt to an irq. */
 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 			     unsigned pirq, int shareable, char *name);