acpi/pci_link: Avoid sharing interrupt with SCI if possible

Since ACPI SCI handler is time consuming, sharing its interrupt
with others may cause significant performance penalty.  SCI
interrupt is now shared if we can't find other resorts.

diff --git a/sys/dev/acpica5/acpi_pci_link.c b/sys/dev/acpica5/acpi_pci_link.c
index b209b6c..3d6bbdc 100644 (file)
--- a/sys/dev/acpica5/acpi_pci_link.c
+++ b/sys/dev/acpica5/acpi_pci_link.c
@@ -674,7 +674,13 @@ acpi_pci_link_add_reference(device_t dev, int index, device_t pcib, int slot,
                    bios_irq, (int)bus, slot, pin + 'A');
        } else if (!PCI_INTERRUPT_VALID(link->l_bios_irq)) {
                link->l_bios_irq = bios_irq;
-               if (bios_irq < NUM_ISA_INTERRUPTS)
+               /*
+                * Avoid sharing interrupt with SCI if possible,
+                * since ACPI interrupt handler is generally time
+                * consuming.
+                */
+               if (bios_irq < NUM_ISA_INTERRUPTS &&
+                   AcpiGbl_FADT.SciInterrupt != bios_irq)
                        pci_link_bios_isa_irqs |= (1 << bios_irq);
                if (bios_irq != link->l_initial_irq &&
                    PCI_INTERRUPT_VALID(link->l_initial_irq))
@@ -1019,10 +1025,9 @@ acpi_pci_link_choose_irq(device_t dev, struct link *link)
        }
 
        /*
-        * If this is an ISA IRQ, try using the SCI if it is also an ISA
-        * interrupt as a fallback.
+        * Check SCI as the last resort.
         */
-       if (link->l_isa_irq) {
+       if (link->l_isa_irq && !PCI_INTERRUPT_VALID(best_irq)) {
                pos_irq = AcpiGbl_FADT.SciInterrupt;
                pos_weight = pci_link_interrupt_weights[pos_irq];
                if (pos_weight < best_weight) {
@@ -1082,30 +1087,8 @@ acpi_pci_link_route_interrupt(device_t dev, int index)
        return (link->l_irq);
 }
 
-/*
- * This is gross, but we abuse the identify routine to perform one-time
- * SYSINIT() style initialization for the driver.
- */
-static void
-acpi_pci_link_identify(driver_t *driver, device_t parent)
-{
-
-       /*
-        * If the SCI is an ISA IRQ, add it to the bitmask of known good
-        * ISA IRQs.
-        *
-        * XXX: If we are using the APIC, the SCI might have been
-        * rerouted to an APIC pin in which case this is invalid.  However,
-        * if we are using the APIC, we also shouldn't be having any PCI
-        * interrupts routed via ISA IRQs, so this is probably ok.
-        */
-       if (AcpiGbl_FADT.SciInterrupt < NUM_ISA_INTERRUPTS)
-               pci_link_bios_isa_irqs |= (1 << AcpiGbl_FADT.SciInterrupt);
-}
-
 static device_method_t acpi_pci_link_methods[] = {
        /* Device interface */
-       DEVMETHOD(device_identify,      acpi_pci_link_identify),
        DEVMETHOD(device_probe,         acpi_pci_link_probe),
        DEVMETHOD(device_attach,        acpi_pci_link_attach),
        DEVMETHOD(device_resume,        acpi_pci_link_resume),