Примерно так:
static unsigned int nvecs[] = { 1, 2, 4, 8, 16, 32, 1, 1 };
// Setting up interrupt handler
pdata->nvec = pci_alloc_irq_vectors(pdev,1,
nvecs[(regval >> 4) & 0x7],
PCI_IRQ_MSI);
if(pdata->nvec < 0)
dev_err(&pdev->dev,"Unable to allocate interrupt vectors");
else {
dev_info(&pdev->dev,"MSI Vectors: %d",pdata->nvec);
for(i = 0; i < pdata->nvec; i++) {
vn = pci_irq_vector(pdev,i);
ret = request_irq(vn,pf_isr,IRQF_SHARED,
pci_name(pdev),pdev);
if(ret < 0)
dev_err(&pdev->dev,
"Unable to register irq %d",vn);
}
}
// ISR
irqreturn_t pf_isr(int irq, void *dev_id)
{
struct pci_dev *pdev = (struct pci_dev *)dev_id;
struct pf_data *pdata = pci_get_drvdata(pdev);
int nirq = irq - pdata->pdev->irq;
...
в nirq при этом - номер MSI-прерывания, которое произошло
