/*
* File: msi.c
* Purpose: PCI Message Signaled Interrupt (MSI)
*
* Copyright (C) 2003-2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
*/
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/msi.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "pci.h"
static int pci_msi_enable = 1;
#define msix_table_size(flags) ((flags & PCI_MSIX_FLAGS_QSIZE) + 1)
/* Arch hooks */
#ifndef arch_msi_check_device
int arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
{
return 0;
}
#endif
#ifndef arch_setup_msi_irqs
# define arch_setup_msi_irqs default_setup_msi_irqs
# define HAVE_DEFAULT_MSI_SETUP_IRQS
#endif
#ifdef HAVE_DEFAULT_MSI_SETUP_IRQS
int default_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
struct msi_desc *entry;
int ret;
/*
* If an architecture wants to support multiple MSI, it needs to
* override arch_setup_msi_irqs()
*/
if (type == PCI_CAP_ID_MSI && nvec > 1)
return 1;
list_for_each_entry(entry, &dev->msi_list, list) {
ret = arch_setup_msi_irq(dev, entry);
if (ret < 0)
return ret;
if (ret > 0)
return -ENOSPC;
}
return 0;
}
#endif
#ifndef arch_teardown_msi_irqs
# define arch_teardown_msi_irqs default_teardown_msi_irqs
# define HAVE_DEFAULT_MSI_TEARDOWN_IRQS
#endif
#ifdef HAVE_DEFAULT_MSI_TEARDOWN_IRQS
void default_teardown_msi_irqs(struct pci_dev *dev)
{
struct msi_desc *entry;
list_for_each_entry(entry, &dev->msi_list, list) {
int i, nvec;
if (entry->irq == 0)
continue;
nvec = 1 << entry->msi_attrib.multiple;
for (i = 0; i < nvec; i++)
arch_teardown_msi_irq(entry->irq + i);
}
}
#endif
#ifndef arch_restore_msi_irqs
# define arch_restore_msi_irqs default_restore_msi_irqs
# define HAVE_DEFAULT_MSI_RESTORE_IRQS
#endif
#ifdef HAVE_DEFAULT_MSI_RESTORE_IRQS
void default_restore_msi_irqs(struct pci_dev *dev, int irq)
{
struct msi_desc *entry;
entry = NULL;
if (dev->msix_enabled) {
list_for_each_entry(entry, &dev->msi_list, list) {
if (irq == entry->irq)
break;
}
} else if (dev->msi_enabled) {
entry = irq_get_msi_desc(irq);
}
if (entry)
write_msi_msg(irq, &entry->msg);
}
#endif
static void msi_set_enable(struct pci_dev *dev, int enable)
{
u16 control;
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
control &= ~PCI_MSI_FLAGS_ENABLE;
if (enable)
control |= PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
}
static void msix_set_enable(struct pci_dev *dev, int enable)
{
u16 control;
pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
control &= ~PCI_MSIX_FLAGS_ENABLE;
if (enable)
control |= PCI_MSIX_FLAGS_ENABLE;
pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, control);
}
static inline __attribute_const__ u32 msi_mask(unsigned x)
{
/* Don't shift by >= width of type */
if (x >= 5)
return 0xffffffff;
return (1 << (1 << x)) - 1;
}
static inline __attribute_const__ u32 msi_capable_mask(u16 control)
{
return msi_mask((control >> 1) & 7);
}
static inline __attribute_const__ u32 msi_enabled_mask(u16 control)
{
return msi_mask((control >> 4) & 7);
}
/*
* PCI 2.3 does not specify mask bits for each MSI interrupt. Attempting to
* mask all MSI interrupts by clearing the MSI enable bit does not work
* reliably as devices without an INTx disable bit will then generate a
* level IRQ which will never be cleared.
*/