From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Map MSIs into pirqs, writing 0 in the MSI vector data field and the pirq
number in the MSI destination id field.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
arch/x86/pci/xen.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/xen/events.c | 22 +++++++++++++++++++
include/xen/events.h | 2 +
3 files changed, 81 insertions(+), 0 deletions(-)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index bfbe185..6fbc81a 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -56,10 +56,62 @@ int xen_hvm_register_pirq(u32 gsi, int triggering)
#if defined(CONFIG_PCI_MSI)
#include <linux/msi.h>
+#include <asm/msidef.h>
struct xen_pci_frontend_ops *xen_pci_frontend;
EXPORT_SYMBOL_GPL(xen_pci_frontend);
+static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
+ struct msi_msg *msg)
+{
+ /* We set vector == 0 to tell the hypervisor we don't care about it,
+ * but we want a pirq setup instead.
+ * We use the dest_id field to pass the pirq that we want. */
+ msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
+ msg->address_lo =
+ MSI_ADDR_BASE_LO |
+ MSI_ADDR_DEST_MODE_PHYSICAL |
+ MSI_ADDR_REDIRECTION_CPU |
+ MSI_ADDR_DEST_ID(pirq);
+
+ msg->data =
+ MSI_DATA_TRIGGER_EDGE |
+ MSI_DATA_LEVEL_ASSERT |
+ /* delivery mode reserved */
+ (3 << 8) |
+ MSI_DATA_VECTOR(0);
+}
+
+static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+ int irq, pirq, ret = 0;
+ struct msi_desc *msidesc;
+ struct msi_msg msg;
+
+ list_for_each_entry(msidesc, &dev->msi_list, list) {
+ xen_allocate_pirq_msi((type == PCI_CAP_ID_MSIX) ?
+ "msi-x" : "msi", &irq, &pirq);
+ if (irq < 0 || pirq < 0)
+ goto error;
+ printk(KERN_DEBUG "xen: msi --> irq=%d, pirq=%d\n", irq, pirq);
+ xen_msi_compose_msg(dev, pirq, &msg);
+ ret = set_irq_msi(irq, msidesc);
+ if (ret < 0)
+ goto error_while;
+ write_msi_msg(irq, &msg);
+ }
+ return 0;
+
+error_while:
+ unbind_from_irqhandler(irq, NULL);
+error:
+ if (ret == -ENODEV)
+ dev_err(&dev->dev, "Xen PCI frontend has not registered" \
+ " MSI/MSI-X support!\n");
+
+ return ret;
+}
+
/*
* For MSI interrupts we have to use drivers/xen/event.s functions to
* allocate an irq_desc and setup the right */
@@ -200,5 +252,10 @@ int __init pci_xen_hvm_init(void)
* just how GSIs get registered.
*/
__acpi_register_gsi = acpi_register_gsi_xen_hvm;
+
+#ifdef CONFIG_PCI_MSI
+ x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
+ x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+#endif
return 0;
}
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index ab4e393..9fdf3c7 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -652,6 +652,28 @@ out:
return irq;
}
+void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
+{
+ spin_lock(&irq_mapping_update_lock);
+
+ *irq = find_unbound_irq();
+ if (*irq == -1)
+ goto out;
+
+ *pirq = find_unbound_pirq();
+ if (*pirq == -1)
+ goto out;
+
+ set_irq_chip_and_handler_name(*irq, &xen_pirq_chip,
+ handle_level_irq, name);
+
+ irq_info[*irq] = mk_pirq_info(0, *pirq, 0, 0);
+ pirq_to_irq[*pirq] = *irq;
+
+out:
+ spin_unlock(&irq_mapping_update_lock);
+}
+
int xen_destroy_irq(int irq)
{
struct irq_desc *desc;
diff --git a/include/xen/events.h b/include/xen/events.h
index b276c38..5e67be7 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -72,6 +72,8 @@ void xen_hvm_evtchn_do_upcall(void);
usual. */
int xen_allocate_pirq(unsigned gsi, int shareable, char *name);
int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name);
+/* Allocate an irq and a pirq to be used with MSIs. */
+void xen_allocate_pirq_msi(char *name, int *irq, int *pirq);
/* De-allocates the above mentioned physical interrupt. */
int xen_destroy_irq(int irq);
--
1.5.6.5
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