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回复 15# chishanmingshen
如果我记得不错的话,应该是在:
arch_setup_msi_irqs()
native_setup_msi_irqs()
setup_msi_irq()
write_msi_msg()
__write_msi_msg()
void __write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
if (entry->dev->current_state != PCI_D0) {
/* Don't touch the hardware now */
} else if (entry->msi_attrib.is_msix) {
void __iomem *base;
base = entry->mask_base +
entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
} else {
struct pci_dev *dev = entry->dev;
int pos = dev->msi_cap;
u16 msgctl;
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
msgctl &= ~PCI_MSI_FLAGS_QSIZE;
msgctl |= entry->msi_attrib.multiple << 4;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
msg->address_lo);
if (entry->msi_attrib.is_64) {
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
msg->address_hi);
pci_write_config_word(dev, pos + PCI_MSI_DATA_64,
msg->data);
} else {
pci_write_config_word(dev, pos + PCI_MSI_DATA_32,
msg->data);
}
}
entry->msg = *msg;
}
写入的数据实际上是特定的编码信息:
void native_compose_msi_msg(struct pci_dev *pdev,
unsigned int irq, unsigned int dest,
struct msi_msg *msg, u8 hpet_id)
{
struct irq_cfg *cfg = irq_cfg(irq);
msg->address_hi = MSI_ADDR_BASE_HI;
if (x2apic_enabled())
msg->address_hi |= MSI_ADDR_EXT_DEST_ID(dest);
msg->address_lo =
MSI_ADDR_BASE_LO |
((apic->irq_dest_mode == 0) ?
MSI_ADDR_DEST_MODE_PHYSICAL:
MSI_ADDR_DEST_MODE_LOGICAL) |
((apic->irq_delivery_mode != dest_LowestPrio) ?
MSI_ADDR_REDIRECTION_CPU:
MSI_ADDR_REDIRECTION_LOWPRI) |
MSI_ADDR_DEST_ID(dest);
msg->data =
MSI_DATA_TRIGGER_EDGE |
MSI_DATA_LEVEL_ASSERT |
((apic->irq_delivery_mode != dest_LowestPrio) ?
MSI_DATA_DELIVERY_FIXED:
MSI_DATA_DELIVERY_LOWPRI) |
MSI_DATA_VECTOR(cfg->vector);
} |
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