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 4fbda9a3f339..968d57dd54c9 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 f567965c0620..1017c7bee388 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 30df85d8fca8..da70f5c32eb9 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 9af21e19545a..d287997d3eab 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);