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Commit 809f9267 authored by Stefano Stabellini's avatar Stefano Stabellini
Browse files

xen: map MSIs into pirqs 



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: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 3942b740

arch/x86/pci/xen.c

+57 −0
Original line number Diff line number Diff line
@@ -64,10 +64,62 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi, 


#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 */
@@ -198,5 +250,10 @@ int __init pci_xen_hvm_init(void) 
	 */

	__acpi_register_gsi = acpi_register_gsi_xen_hvm;

#endif



#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;

}

drivers/xen/events.c

+22 −0
Original line number Diff line number Diff line
@@ -656,6 +656,28 @@ 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;

include/xen/events.h

+2 −0
Original line number Diff line number Diff line
@@ -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);