x86: Add a function to assign IRQ numbers to PCI device
Add a function to assign an IRQ number to PCI device's interrupt
line register in its configuration space, so that the PCI device
can have its interrupt working under PIC mode after OS boots up.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/pci.c b/arch/x86/cpu/pci.c
index e23b233..c209f15 100644
--- a/arch/x86/cpu/pci.c
+++ b/arch/x86/cpu/pci.c
@@ -151,3 +151,24 @@
return 0;
}
+
+void pci_assign_irqs(int bus, int device, int func, u8 irq[4])
+{
+ pci_dev_t bdf;
+ u8 pin, line;
+
+ bdf = PCI_BDF(bus, device, func);
+
+ pin = x86_pci_read_config8(bdf, PCI_INTERRUPT_PIN);
+
+ /* PCI spec says all values except 1..4 are reserved */
+ if ((pin < 1) || (pin > 4))
+ return;
+
+ line = irq[pin - 1];
+
+ debug("Assigning IRQ %d to PCI device %d.%x.%d (INT%c)\n",
+ line, bus, device, func, 'A' + pin - 1);
+
+ x86_pci_write_config8(bdf, PCI_INTERRUPT_LINE, line);
+}