path: root/drivers/pci/msi-apic.c

/*
 * MSI hooks for standard x86 apic
 */

#include <linux/pci.h>
#include <linux/irq.h>
#include <asm/smp.h>

#include "msi.h"

/*
 * Shifts for APIC-based data
 */

#define MSI_DATA_VECTOR_SHIFT		0
#define	    MSI_DATA_VECTOR(v)		(((u8)v) << MSI_DATA_VECTOR_SHIFT)

#define MSI_DATA_DELIVERY_SHIFT		8
#define     MSI_DATA_DELIVERY_FIXED	(0 << MSI_DATA_DELIVERY_SHIFT)
#define     MSI_DATA_DELIVERY_LOWPRI	(1 << MSI_DATA_DELIVERY_SHIFT)

#define MSI_DATA_LEVEL_SHIFT		14
#define     MSI_DATA_LEVEL_DEASSERT	(0 << MSI_DATA_LEVEL_SHIFT)
#define     MSI_DATA_LEVEL_ASSERT	(1 << MSI_DATA_LEVEL_SHIFT)

#define MSI_DATA_TRIGGER_SHIFT		15
#define     MSI_DATA_TRIGGER_EDGE	(0 << MSI_DATA_TRIGGER_SHIFT)
#define     MSI_DATA_TRIGGER_LEVEL	(1 << MSI_DATA_TRIGGER_SHIFT)

/*
 * Shift/mask fields for APIC-based bus address
 */

#define MSI_ADDR_HEADER			0xfee00000

#define MSI_ADDR_DESTID_MASK		0xfff0000f
#define     MSI_ADDR_DESTID_CPU(cpu)	((cpu) << MSI_TARGET_CPU_SHIFT)

#define MSI_ADDR_DESTMODE_SHIFT		2
#define     MSI_ADDR_DESTMODE_PHYS	(0 << MSI_ADDR_DESTMODE_SHIFT)
#define	    MSI_ADDR_DESTMODE_LOGIC	(1 << MSI_ADDR_DESTMODE_SHIFT)

#define MSI_ADDR_REDIRECTION_SHIFT	3
#define     MSI_ADDR_REDIRECTION_CPU	(0 << MSI_ADDR_REDIRECTION_SHIFT)
#define     MSI_ADDR_REDIRECTION_LOWPRI	(1 << MSI_ADDR_REDIRECTION_SHIFT)


static void
msi_target_apic(unsigned int irq, cpumask_t cpu_mask, struct msi_msg *msg)
{
	u32 addr = msg->address_lo;

	addr &= MSI_ADDR_DESTID_MASK;
	addr |= MSI_ADDR_DESTID_CPU(cpu_physical_id(first_cpu(cpu_mask)));

	msg->address_lo = addr;
}

static int
msi_setup_apic(struct pci_dev *pdev,	/* unused in generic */
		unsigned int irq,
		struct msi_msg *msg)
{
	unsigned long	dest_phys_id;
	unsigned int	vector;

	dest_phys_id = cpu_physical_id(first_cpu(cpu_online_map));
	vector = irq;

	msg->address_hi = 0;
	msg->address_lo =
		MSI_ADDR_HEADER |
		MSI_ADDR_DESTMODE_PHYS |
		MSI_ADDR_REDIRECTION_CPU |
		MSI_ADDR_DESTID_CPU(dest_phys_id);

	msg->data =
		MSI_DATA_TRIGGER_EDGE |
		MSI_DATA_LEVEL_ASSERT |
		MSI_DATA_DELIVERY_FIXED |
		MSI_DATA_VECTOR(vector);

	return 0;
}

static void
msi_teardown_apic(unsigned int irq)
{
	return;		/* no-op */
}

/*
 * Generic ops used on most IA archs/platforms.  Set with msi_register()
 */

struct msi_ops msi_apic_ops = {
	.needs_64bit_address = 0,
	.setup = msi_setup_apic,
	.teardown = msi_teardown_apic,
	.target = msi_target_apic,
};